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Publisher: Elsevier   (Total: 3118 journals)

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Showing 1 - 200 of 3118 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 7)
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 25, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 22, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 89, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 30, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 372, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 27, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 1)
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 235, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 10, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 25, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 4, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 5)
Acute Pain     Full-text available via subscription   (Followers: 13)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 6)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 3)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 136, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 27, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 11, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 22, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 26, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 4)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 13)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 26, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 9, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 29, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Dermatology     Full-text available via subscription   (Followers: 12)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 12)
Advances in Digestive Medicine     Open Access   (Followers: 7)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 6)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 46, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 26, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 8)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 44, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 52, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 22, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 2)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 23)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 9, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 4)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 24, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 13)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 62)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.1, h-index: 2)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Space Research     Full-text available via subscription   (Followers: 367, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Surgery     Full-text available via subscription   (Followers: 8, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 31, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 16)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 6, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 45, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 335, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 5, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 9, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 445, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 41, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 56, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 5, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 11, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 8)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access   (Followers: 1)
Algal Research     Partially Free   (Followers: 9, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 4, SJR: 0.776, h-index: 35)
Alpha Omegan     Full-text available via subscription   (SJR: 0.121, h-index: 9)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 48, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 49, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 48, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 41, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 9, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 26, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 31, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 46, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 204, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 60, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 6)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 24, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 27, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 26, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 35, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 59, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 13)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 4, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 36, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 164, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 8, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 12)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 1)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 22, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  

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Journal Cover Acta Oecologica
  [SJR: 0.915]   [H-I: 53]   [10 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1146-609X
   Published by Elsevier Homepage  [3118 journals]
  • Soil conditions drive changes in a key leaf functional trait through
           environmental filtering and facilitative interactions
    • Authors: Rafael Molina-Venegas; Abelardo Aparicio; Sébastien Lavergne; Juan Arroyo
      Pages: 1 - 8
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): Rafael Molina-Venegas, Abelardo Aparicio, Sébastien Lavergne, Juan Arroyo
      Non-random patterns in the functional structure of communities are often interpreted as evidence for different forces governing their assemblage. However, community assembly processes may act antagonistically, countering each other's signatures on the functional structure of communities, which may lead to spurious inferences on the underlying mechanisms. To illustrate this issue, we assessed the joint effects of environmental filtering and facilitative interactions on a key leaf functional trait (i.e. specific leaf area, SLA) in Mediterranean dwarf-shrub communities, using a two-scale sampling approach. Specifically, we analyzed differences in community-weighted mean SLA values (CWM-SLA) between communities (community-scale) and between guilds within communities (guild-scale, i.e. individuals sampled in understorey, overstorey and open-ground conditions) across contrasted soil environments and elevational gradients. We found that communities on harsh edaphic conditions (i.e. dolomite habitats) showed significantly lower CWM-SLA values than communities on more fertile habitats. In contrast, elevation was a poor predictor of differences in CWM-SLA between the communities. This suggests that environmental filtering may influence leaf trait variation along soil gradients irrespective of elevation. On the other hand, communities on dolomite habitats showed strong differences in CWM-SLA between understorey (higher CWM-SLA) and either open-ground and overstorey guilds (lower CWM-SLA), whereas communities on more fertile soils showed no differences between the guilds. The strong differences in CWM-SLA between understorey and non-understorey guilds in dolomite communities suggest that facilitative interactions may be particularly at stake under stressful edaphic conditions, thus partially mitigating the effect of environmental filtering (i.e. low SLA values) on communities growing in harsh soils.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.008
      Issue No: Vol. 86 (2017)
       
  • Herbivory alters plant carbon assimilation, patterns of biomass allocation
           and nitrogen use efficiency
    • Authors: María Laura Peschiutta; Fabián Gustavo Scholz; Guillermo Goldstein; Sandra Janet Bucci
      Pages: 9 - 16
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): María Laura Peschiutta, Fabián Gustavo Scholz, Guillermo Goldstein, Sandra Janet Bucci
      Herbivory can trigger physiological processes resulting in leaf and whole plant functional changes. The effects of chronic infestation by an insect on leaf traits related to carbon and nitrogen economy in three Prunus avium cultivars were assessed. Leaves from non-infested trees (control) and damaged leaves from infested trees were selected. The insect larvae produce skeletonization of the leaves leaving relatively intact the vein network of the eaten leaves and the abaxial epidermal tissue. At the leaf level, nitrogen content per mass (N mass) and per area (N area), net photosynthesis per mass (A mass) and per area (A area), photosynthetic nitrogen-use efficiency (PNUE), leaf mass per area (LMA) and total leaf phenols content were measured in the three cultivars. All cultivars responded to herbivory in a similar fashion. The N mass, A mass, and PNUE decreased, while LMA and total content of phenols increased in partially damaged leaves. Increases in herbivore pressure resulted in lower leaf size and total leaf area per plant across cultivars. Despite this, stem cumulative growth tended to increase in infected plants suggesting a change in the patterns of biomass allocation and in resources sequestration elicited by herbivory. A larger N investment in defenses instead of photosynthetic structures may explain the lower PNUE and A mass observed in damaged leaves. Some physiological changes due to herbivory partially compensate for the cost of leaf removal buffering the carbon economy at the whole plant level.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.007
      Issue No: Vol. 86 (2017)
       
  • Predation risk of artificial ground nests in managed floodplain meadows
    • Authors: Susanne Arbeiter; Elisabeth Franke
      Pages: 17 - 22
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): Susanne Arbeiter, Elisabeth Franke
      Nest predation highly determines the reproductive success in birds. In agricultural grasslands, vegetation characteristics and management practices influences the predation risk of ground breeders. Little is known so far on the predation pressure on non-passerine nests in tall swards. Investigations on the interaction of land use with nesting site conditions and the habitat selection of nest predators are crucial to develop effective conservation measures for grassland birds. In this study, we used artificial nests baited with quail and plasticine eggs to identify potential predators of ground nests in floodplain meadows and related predation risk to vegetation structure and grassland management. Mean daily predation rate was 0.01 (±0.012) after an exposure duration of 21 days. 70% of all observed nest predations were caused by mammals (Red Fox and mustelids) and 17.5% by avian predators (corvids). Nest sites close to the meadow edge and those providing low forb cover were faced with a higher daily predation risk. Predation risk also increased later in the season. Land use in the preceding year had a significant effect on predation risk, showing higher predation rates on unmanaged sites than on mown sites. Unused meadows probably attract mammalian predators, because they provide a high abundance of small rodents and a more favourable vegetation structure for foraging, increasing also the risk of incidental nest predations. Although mowing operation is a major threat to ground-nesting birds, our results suggest that an annual removal of vegetation may reduce predation risk in the subsequent year.
      Graphical abstract image

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.012
      Issue No: Vol. 86 (2017)
       
  • Analysis of spatial patterns informs community assembly and sampling
           requirements for Collembola in forest soils
    • Authors: Tara Dirilgen; Edite Juceviča; Viesturs Melecis; Pascal Querner; Thomas Bolger
      Pages: 23 - 30
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): Tara Dirilgen, Edite Juceviča, Viesturs Melecis, Pascal Querner, Thomas Bolger
      The relative importance of niche separation, non-equilibrial and neutral models of community assembly has been a theme in community ecology for many decades with none appearing to be applicable under all circumstances. In this study, Collembola species abundances were recorded over eleven consecutive years in a spatially explicit grid and used to examine (i) whether observed beta diversity differed from that expected under conditions of neutrality, (ii) whether sampling points differed in their relative contributions to overall beta diversity, and (iii) the number of samples required to provide comparable estimates of species richness across three forest sites. Neutrality could not be rejected for 26 of the forest by year combinations. However, there is a trend toward greater structure in the oldest forest, where beta diversity was greater than predicted by neutrality on five of the eleven sampling dates. The lack of difference in individual- and sample-based rarefaction curves also suggests randomness in the system at this particular scale of investigation. It seems that Collembola communities are not spatially aggregated and assembly is driven primarily by neutral processes particularly in the younger two sites. Whether this finding is due to small sample size or unaccounted for environmental variables cannot be determined. Variability between dates and sites illustrates the potential of drawing incorrect conclusions if data are collected at a single site and a single point in time.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.010
      Issue No: Vol. 86 (2017)
       
  • Genetic diversity of dispersed seeds is highly variable among leks of the
           long-wattled umbrellabird
    • Authors: Kym Ottewell; Luke Browne; Domingo Cabrera; Jorge Olivo; Jordan Karubian
      Pages: 31 - 37
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): Kym Ottewell, Luke Browne, Domingo Cabrera, Jorge Olivo, Jordan Karubian
      Frugivorous animals frequently generate clumped distributions of seeds away from source trees, but genetic consequences of this phenomenon remain poorly resolved. Seed dispersal of the palm Oenocarpus bataua by long-wattled umbrellabirds Cephalopterus penduliger generates high seed densities in leks (i.e., multi-male display sites), providing a suitable venue to investigate how dispersal by this frugivore may influence seed source diversity and genetic structure at local and landscape levels. We found moderate levels of maternal seed source diversity in primary seed rain across five leks in northwest Ecuador (unweighted mean alpha diversity α = 9.52, weighted mean αr = 3.52), with considerable variation among leks (αr range: 1.81–24.55). Qualitatively similar findings were obtained for allelic diversity and heterozygosity. Higher densities of O. bataua adults around leks were associated with higher values of αr and heterozygosity (non-significant trends) and allelic diversity (significant correlation). Seed source overlap between different leks was not common but did occur at low frequency, providing evidence for long-distance seed dispersal by umbrellabirds into leks. Our findings are consistent with the idea that seed pool diversity within leks may be shaped by the interaction between density of local trees, which can vary considerably between leks, and umbrellabird foraging ecology, particularly a lack of territorial defense of fruiting trees. Taken as a whole, this work adds to our growing appreciation of the ways resource distribution and associated frugivore foraging behaviors mechanistically shape seed dispersal outcomes and the distribution of plant genotypes across the landscape.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.016
      Issue No: Vol. 86 (2017)
       
  • Intra-specific downsizing of frugivores affects seed germination of
           fleshy-fruited plant species
    • Authors: Néstor Pérez-Méndez; Airam Rodríguez; Manuel Nogales
      Pages: 38 - 41
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): Néstor Pérez-Méndez, Airam Rodríguez, Manuel Nogales
      The loss of largest-bodied individuals within species of frugivorous animals is one of the major consequences of defaunation. The gradual disappearance of large-bodied frugivores is expected to entail a parallel deterioration in seed dispersal functionality if the remaining smaller-sized individuals are not so effective as seed dispersers. While the multiple impacts of the extinction of large bodied species have been relatively well studied, the impact of intraspecific downsizing (i.e. the extinction of large individuals within species) on seed dispersal has rarely been evaluated. Here we experimentally assessed the impact of body-size reduction in the frugivorous lizard Gallotia galloti (Lacertidae), an endemic species of the Canary Islands, on the seed germination patterns of two fleshy-fruited plant species (Rubia fruticosa and Withania aristata). Seed germination curves and the proportions of germinated seeds were compared for both plant species after being defecated by large-sized individuals and small-sized individuals. The data show that seeds of W. aristata defecated by larger-sized lizards germinated faster and in a higher percentage than those defecated by small-sized lizards, while no differences were found for R. fruticosa seeds. Our results suggest that disappearance of the largest individuals of frugivorous species may impair recruitment of some plant species by worsening seed germination. They also warn us of a potential cryptic loss of seed dispersal functionality on defaunated ecosystems, even when frugivorous species remain abundant.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.017
      Issue No: Vol. 86 (2017)
       
  • Rangewide determinants of population performance in Prunus lusitanica:
           Lessons for the contemporary conservation of a Tertiary relict tree
    • Authors: Adara Pardo; Yonatan Cáceres; Fernando Pulido
      Pages: 42 - 48
      Abstract: Publication date: January 2018
      Source:Acta Oecologica, Volume 86
      Author(s): Adara Pardo, Yonatan Cáceres, Fernando Pulido
      Relict species are an extremely important part of biodiversity and as such studies on the factors that allow their current persistence are required. The aim of this study was to assess the determinants of the distribution and range-wide population performance of the Tertiary relict tree Prunus lusitanica L. This threatened species is confined to Iberia, Northern Morocco and Macaronesia with a fragmented and scattered distribution. Using ecological niche modelling, we calculated the level of range filling across the range and tested its relationship with human impact. We then assessed the relative importance of climatic suitability as obtained through niche modelling, topographic factors and contemporary human impact on range-wide population performance. Results showed that the species occupies only 2.4% of the overall area predicted to be climatically suitable for its presence and the level of range filling varied across regions. A weak negative relationship among range filling and human impact was found. Overall climatic suitability was the strongest predictor of population performance. However, it showed high variability across regions: the effect was positive in Iberia whereas negative but not significant in Macaronesia and Morocco. Human impact showed a significant negative effect and finally topographic factors such as altitude had a minor negative effect. Our results highlight that both climate and human impact play a major role in the current limited range filling and performance of the species. Management plans to minimize anthropogenic disturbances together with reforestation measures are urgently needed in order to conserve this unique species.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.12.001
      Issue No: Vol. 86 (2017)
       
  • Trade-off between light availability and soil fertility determine refugial
           conditions for the relict light-demanding species in lowland forests
    • Authors: Marcin Kiedrzyński; Józef Krzysztof Kurowski; Edyta Kiedrzyńska
      Pages: 1 - 8
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Marcin Kiedrzyński, Józef Krzysztof Kurowski, Edyta Kiedrzyńska
      Identifying potential refugial habitats in the face of rapid environmental change is a challenge faced by scientists and nature conservation managers. Relict populations and refugial habitats are the model objects in those studies. Based on the example of Actaea europaea from Central Poland, we analyse the habitat factors influencing relict populations of continental, light-demanding species in lowland forests and examine which habitats of studied species corresponding most closely to ancient vegetation. Our results indicate that the current refugial habitats of Actaea europaea include not only communities which are very similar to ancient open forest but also forests with a closed canopy. Although the populations are influenced by nitrogen and light availability, the co-occurrence of these two factors in forest communities is limited by dense canopy formation by hornbeam and beech trees on fertile soils and in more humid conditions. Our findings indicate that the future survival of relict, light-demanding communities in lowland forests requires low-intensity disturbances to be performed in tree-stands, according to techniques, which imitate traditional forests management.

      PubDate: 2017-09-17T15:20:16Z
      DOI: 10.1016/j.actao.2017.09.004
      Issue No: Vol. 85 (2017)
       
  • Temporal variation in bat-fruit interactions: Foraging strategies
           influence network structure over time
    • Authors: Natalya Zapata-Mesa; Sebastián Montoya-Bustamante; Oscar E. Murillo-García
      Pages: 9 - 17
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Natalya Zapata-Mesa, Sebastián Montoya-Bustamante, Oscar E. Murillo-García
      Mutualistic interactions, such as seed dispersal, are important for the maintenance of structure and stability of tropical communities. However, there is a lack of information about spatial and temporal variation in plant-animal interaction networks. Thus, our goal was to assess the effect of bat's foraging strategies on temporal variation in the structure and robustness of bat-fruit networks in both a dry and a rain tropical forest. We evaluated monthly variation in bat-fruit networks by using seven structure metrics: network size, average path length, nestedness, modularity, complementary specialization, normalized degree and betweenness centrality. Seed dispersal networks showed variations in size, species composition and modularity; did not present nested structures and their complementary specialization was high compared to other studies. Both networks presented short path lengths, and a constantly high robustness, despite their monthly variations. Sedentary bat species were recorded during all the study periods and occupied more central positions than nomadic species. We conclude that foraging strategies are important structuring factors that affect the dynamic of networks by determining the functional roles of frugivorous bats over time; thus sedentary bats are more important than nomadic species for the maintenance of the network structure, and their conservation is a must.

      PubDate: 2017-09-17T15:20:16Z
      DOI: 10.1016/j.actao.2017.09.003
      Issue No: Vol. 85 (2017)
       
  • Light as a regulator of structural and chemical leaf defenses against
           insects in two Prunus species
    • Authors: Ewa Mąderek; Marcin Zadworny; Joanna Mucha; Piotr Karolewski
      Pages: 18 - 24
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Ewa Mąderek, Marcin Zadworny, Joanna Mucha, Piotr Karolewski
      Light is a key factor influencing competition between species, and the mechanisms by which trees overcome insect outbreaks can be associated with alternation of the leaves structure, which then prevent or promotes their susceptibility to herbivores. It was predicted that leaf tissue anatomy would likely be different in sun and shade leaves, with a gradual decline of leaves resistance coupled with reduction of accessible light. We quantified anatomical patterns and the distribution of defence compounds (phenols, total tannins, catechol tannins) within heavily grazed leaves of Prunus padus, native in Europe and Prunus serotina, an invasive to Central Europe. Both species were strongly attacked by folivorous insects when shrubs grew in the shade. In the sun, however only P. padus leaves were grazed, but P. serotina leaves were almost unaffected. We identified that anatomical characteristics are not linked to different P. padus and P. serotina leaf vulnerability to insects. Furthermore, the staining of defence compounds of P. serotina leaves grown in full sun revealed that the palisade mesophyll cells had a higher content of phenolic compounds and catechol tannins. Thus, our results indicate that a specific distribution of defence compounds, but not the anatomical relationships between palisade and spongy mesophyll, may be beneficial for P. serotina growth outside its natural range. The identified pattern of defence compounds distribution is linked to a lower susceptibility of P. serotina leaves to herbivores, and is associated with its invasiveness. This likely reflects that P. serotina is a stronger competitor than P. padus, especially at high sunlit sites i.e. gaps in the forest.

      PubDate: 2017-09-24T01:57:02Z
      DOI: 10.1016/j.actao.2017.09.002
      Issue No: Vol. 85 (2017)
       
  • Physiological plasticity of epiphytic orchids from two contrasting
           tropical dry forests
    • Authors: Edilia de la Rosa-Manzano; José Luis Andrade; Gerhard Zotz; Casandra Reyes-García
      Pages: 25 - 32
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Edilia de la Rosa-Manzano, José Luis Andrade, Gerhard Zotz, Casandra Reyes-García
      An enormous variation in light, both temporally and spatially, exists in tropical forests, which represents a potential driver for plant physiological plasticity. The physiological plasticity of epiphytic orchids from two tropical dry forests in response to different light environments was experimentally investigated. Plants of five species were growing in a shade-house under three different light regimes (photosynthetic photon flux density; PPFD of 20, 50 and 70% of total daily incident radiation) under watered and drought conditions. Orchids with similar leaf morphology but from different forests responded differently to the same light environment. Linear leaves of Encyclia nematocaulon avoided drought stress through stomata control and had a notable increase of photosynthesis, lower osmotic potential, and high photosynthetic efficiency under 50% daily PPFD during both drought and watered periods. In contrast, orchids with cylindrical and oval leaves had a marked decrease of these physiological parameters under 50 and 70% of PPFD during the drought period, but then recovered after rewatering. Oval leaves of Lophiaris oerstedii were more sensitive to high light and water availability because they had a strong decrease of their physiological parameters at 70% of PPFD, even during the rewatering period. Contrary to our predictions, E. nematocaulon had low plasticity and Laelia rubescens, from the deciduous forest, was the most able to acclimate. In general, orchids from the drier forest had higher plasticity than those from the more humid forest, which might help them to tolerate the higher fluctuations of light and water availability that occur there.

      PubDate: 2017-09-24T01:57:02Z
      DOI: 10.1016/j.actao.2017.09.006
      Issue No: Vol. 85 (2017)
       
  • Spatial pattern of Baccharis platypoda shrub as determined by sex and life
           stages
    • Authors: Darliana da Costa Fonseca; Marcio Leles Romarco de Oliveira; Israel Marinho Pereira; Anne Priscila Dias Gonzaga; Cristiane Coelho de Moura; Evandro Luiz Mendonça Machado
      Pages: 33 - 43
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Darliana da Costa Fonseca, Marcio Leles Romarco de Oliveira, Israel Marinho Pereira, Anne Priscila Dias Gonzaga, Cristiane Coelho de Moura, Evandro Luiz Mendonça Machado
      Spatial patterns of dioecious species can be determined by their nutritional requirements and intraspecific competition, apart from being a response to environmental heterogeneity. The aim of the study was to evaluate the spatial pattern of populations of a dioecious shrub reporting to sex and reproductive stage patterns of individuals. Sampling was carried out in three areas located in the meridional portion of Serra do Espinhaço, where in individuals of the studied species were mapped. The spatial pattern was determined through O-ring analysis and Ripley's K-function and the distribution of individuals' frequencies was verified through x 2 test. Populations in two areas showed an aggregate spatial pattern tending towards random or uniform according to the observed scale. Male and female adults presented an aggregate pattern at smaller scales, while random and uniform patterns were verified above 20 m for individuals of both sexes of the areas A2 and A3. Young individuals presented an aggregate pattern in all areas and spatial independence in relation to adult individuals, especially female plants. The interactions between individuals of both genders presented spatial independence with respect to spatial distribution. Baccharis platypoda showed characteristics in accordance with the spatial distribution of savannic and dioecious species, whereas the population was aggregated tending towards random at greater spatial scales. Young individuals showed an aggregated pattern at different scales compared to adults, without positive association between them. Female and male adult individuals presented similar characteristics, confirming that adult individuals at greater scales are randomly distributed despite their distinct preferences for environments with moisture variation.

      PubDate: 2017-09-24T01:57:02Z
      DOI: 10.1016/j.actao.2017.09.001
      Issue No: Vol. 85 (2017)
       
  • Effects of grassland degradation and precipitation on carbon storage
           
    • Authors: Xiaobing Li; Yunxiao Bai; Wanyu Wen; Hong Wang; Ruihua Li; Guoqing Li; Han Wang
      Pages: 44 - 52
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Xiaobing Li, Yunxiao Bai, Wanyu Wen, Hong Wang, Ruihua Li, Guoqing Li, Han Wang
      Environmental degradation influences carbon (C) cycling and storage in grassland ecosystems by altering vegetation productivity. However, the impacts of different degradation intensities on vegetation–soil C distributions in grasslands have not been well documented. We measured C storage in soil, roots, and plants under light, moderate, and severe degradation levels in a typical steppe region of Xilinhot, Inner Mongolia, China in 2011 and 2012. Grassland C storage was highest in soil, followed by roots, and then aboveground plant biomass. Grassland degradation and precipitation significantly influenced C storage distributions. During the dry year (2011), total C storage in vegetation and soil was highest under light degradation. Carbon storage in aboveground plant biomass and roots increased with degradation intensity. During the wet year (2012), C storage was highest in aboveground plant biomass and roots under light degradation. Root biomass tended to be concentrated in the soil surface during the wet year.

      PubDate: 2017-09-24T01:57:02Z
      DOI: 10.1016/j.actao.2017.09.008
      Issue No: Vol. 85 (2017)
       
  • Population demography of alpine butterflies: Boloria pales and Boloria
           napaea (Lepidoptera: Nymphalidae) and their specific adaptations to high
           mountain environments
    • Authors: Stefan Ehl; Marlene Ebertshäuser; Patrick Gros; Thomas Schmitt
      Pages: 53 - 61
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Stefan Ehl, Marlene Ebertshäuser, Patrick Gros, Thomas Schmitt
      High mountain ecosystems are extreme habitats, and adaptation strategies to this ecosystem are still poorly understood in most groups. To unravel such strategies, we performed a MRR study in the Hohe Tauern National Park (Salzburg, Austria) with two nymphalid butterfly species, Boloria pales and B. napaea. We analysed their population structure over one flight period by studying the development of population size and wing wear. B. pales had more individuals and a higher survival probability than B. napaea; the sensitivity to extreme weather conditions or other external influences was higher in B. napaea. We only observed proterandry in B. pales. Imagines of both species survived under snow for at least some days. Additionally, we observed a kind of risk-spreading, in that individuals of both species, and especially B. pales, have regularly emerged throughout the flight period. This emergence pattern divided the population's age structure into three phases: an initial phase with decreasing wing quality (emergence > mortality), followed by an equilibrium phase with mostly constant average wing condition (emergence = mortality) and a final ageing phase with strongly deteriorating wing condition (mortality » emergence). Consequently, neither species would likely become extinct because of particularly unsuitable weather conditions during a single flight period. The observed differences between the two species suggest a better regional adaptation of B. pales, which is restricted to high mountain systems of Europe. In contrast, the arctic-alpine B. napaea might be best adapted to conditions in the Arctic and not the more southern high mountain systems. However, this needs to be examined during future research in the Arctic.

      PubDate: 2017-09-24T01:57:02Z
      DOI: 10.1016/j.actao.2017.09.009
      Issue No: Vol. 85 (2017)
       
  • Identification of the key ecological factors influencing vegetation
           
    • Authors: Yu Peng; Qinghui Wang; Min Fan
      Pages: 62 - 68
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Yu Peng, Qinghui Wang, Min Fan
      When assessing re-vegetation project performance and optimizing land management, identification of the key ecological factors inducing vegetation degradation has crucial implications. Rainfall, temperature, elevation, slope, aspect, land use type, and human disturbance are ecological factors affecting the status of vegetation index. However, at different spatial scales, the key factors may vary. Using Helin County, Inner-Mongolia, China as the study site and combining remote sensing image interpretation, field surveying, and mathematical methods, this study assesses key ecological factors affecting vegetation degradation under different spatial scales in a semi-arid agro-pastoral ecotone. It indicates that the key factors are different at various spatial scales. Elevation, rainfall, and temperature are identified as crucial for all spatial extents. Elevation, rainfall and human disturbance are key factors for small-scale quadrats of 300 m × 300 m and 600 m × 600 m, temperature and land use type are key factors for a medium-scale quadrat of 1 km × 1 km, and rainfall, temperature, and land use are key factors for large-scale quadrats of 2 km × 2 km and 5 km × 5 km. For this region, human disturbance is not the key factor for vegetation degradation across spatial scales. It is necessary to consider spatial scale for the identification of key factors determining vegetation characteristics. The eco-restoration programs at various spatial scales should identify key influencing factors according their scales so as to take effective measurements. The new understanding obtained in this study may help to explore the forces which driving vegetation degradation in the degraded regions in the world.

      PubDate: 2017-09-30T02:34:44Z
      DOI: 10.1016/j.actao.2017.09.011
      Issue No: Vol. 85 (2017)
       
  • Frugivorous birds influence the spatial organization of tropical forests
           
    • Authors: Franck Trolliet; Pierre-Michel Forget; Jean-Louis Doucet; Jean-François Gillet; Alain Hambuckers
      Pages: 69 - 76
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Franck Trolliet, Pierre-Michel Forget, Jean-Louis Doucet, Jean-François Gillet, Alain Hambuckers
      Animal-mediated seed dispersal is recognized to influence the spatial organization of plant communities but little is known about how frugivores cause such patterns. Here, we explored the role of hornbills and primates in generating recruitment foci under two zoochoric trees, namely Staudtia kamerunensis (Myristicaceae) and Dialium spp. (Fabaceae - Caesalpiniodea) in a forest-savanna mosaic landscape in D.R. Congo. We also examined the influence of the availability of fruits in the neighborhood and the amount of forest cover in the landscape on such clumping patterns. The density and species richness of hornbill-dispersed and the density of primate-dispersed seedlings were significantly higher under Staudtia kamerunensis trees than at control locations. However, we did not find such patterns under Dialium spp. trees compared to control locations except for the density of hornbill-dispersed seedlings which was lower at control locations. Also, we found that an increasing amount of forest cover in the landscape was associated with an increase in the density of hornbill-dispersed seedlings, although the tendency was weak (R2 = 0.065). We concluded that S. kamerunensis acts as a recruitment foci and plays a structuring role in Afrotropical forests. Hornbills were probably the main frugivore taxon responsible for the clumping under that tree and appear as a key ecological component in fragmented and disturbed landscapes where the diversity of large frugivores such as primates is reduced. Our findings improve our understanding of the causal mechanisms responsible for the spatial organization of tropical forests.

      PubDate: 2017-09-30T02:34:44Z
      DOI: 10.1016/j.actao.2017.09.010
      Issue No: Vol. 85 (2017)
       
  • Is the Peltogyne gracilipes monodominant forest characterised by distinct
           soils'
    • Authors: Marcelo Trindade Nascimento; Reinaldo Imbrozio Barbosa; Kyle G. Dexter; Carolina Volkmer de Castilho; Lidiany Camila da Silva Carvalho; Dora Maria Villela
      Pages: 104 - 107
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Marcelo Trindade Nascimento, Reinaldo Imbrozio Barbosa, Kyle G. Dexter, Carolina Volkmer de Castilho, Lidiany Camila da Silva Carvalho, Dora Maria Villela
      Various explanations have been put forward for monodominance in otherwise diverse tropical forests. This study assesses if the monodominance of Peltogyne gracilipes on Maraca Island in the northern Amazon can be related to edaphic factors. The basal area of P. gracilipes and the five other most common tree species on Maraca Island (Astrocaryum aculeatum, Attalea maripa, Ecclinusa guianensis, Licania kunthiana and Pradosia surinamensis) were recorded in 30 regularly-spaced 0.5 ha plots distributed over an area of 25 km2, for which data on topography and concentration of mineral elements in the soil were also obtained. Stems of P. gracilipes accounted for ≥50% of the basal area in five of the plots, which we consider indicative of monodominance, whilst the highest relative basal area that any of the other species achieved in any plot was 31%. The soils data explained more of the variation in the basal area of P. gracilipes than it did for the other five species. The presence vs. absence and basal area of P. gracilipes was positively related to concentrations of magnesium (Mg), aluminium (Al), iron (Fe), phosphorus (P) and silt in the soil and to Mg:Ca ratios. These soils were found in the plots at the lowest elevations, which suggests that drainage factors may also be important. Overall, our results suggest that edaphic factors may explain, at least partially, monodominance in this Amazonian forest.

      PubDate: 2017-11-05T01:03:51Z
      DOI: 10.1016/j.actao.2017.10.001
      Issue No: Vol. 85 (2017)
       
  • Trunk structural traits explain habitat use of a tree-dwelling spider
           (Selenopidae) in a tropical forest
    • Authors: German Antonio Villanueva-Bonilla; Adriana Trevizoli Salomão; João Vasconcellos-Neto
      Pages: 108 - 115
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): German Antonio Villanueva-Bonilla, Adriana Trevizoli Salomão, João Vasconcellos-Neto
      Habitat selection by spiders may be strongly influenced by biotic, climatic, and physical factors. However, it has been shown that the selection of habitats by generalist predators (like spiders) is regulated more by the physical structure of the habitat than by prey availability. Yet, the preferences of spiders in relation to plants or plant traits remain poorly explored. In a remnant of the Atlantic forest in Brazil, the spider Selenops cocheleti is frequently detected on the trunks of plants from the Myrtaceae family. Here, we investigated quantitatively and experimentally whether the colonization of trees by S. cocheleti is related to plant species or the presence of specific structures on trunks. We found that S. cocheleti preferentially occurred on plants of the family Myrtaceae. This spider was also strongly associated with trees that have smooth trunks and/or exfoliating bark. Non-Myrtaceae plants that were occupied by this species have exfoliating bark (e.g., Piptadenia gonoacantha) or deep fissures on the trunk (e.g., the exotic species Pinus elliottii). Our results indicate that the selection of host plants by S. cocheleti is not species-specific, but based on the structural characteristics of plants. Trunks with exfoliating bark may benefit spiders by providing shelter against predators and harsh climatic conditions. Smooth surfaces might allow rapid movements, facilitating both attacks on preys and escape from predators. Our study emphasizes the importance of the physical structure of the habitat on spider's distribution. Future studies investigating how specific plant characteristics influence prey acquisition and predator avoidance would improve our understanding of habitat selection by these animals.

      PubDate: 2017-11-05T01:03:51Z
      DOI: 10.1016/j.actao.2017.10.004
      Issue No: Vol. 85 (2017)
       
  • Thermodynamics, ecology and evolutionary biology: A bridge over troubled
           water or common ground'
    • Authors: Keith R. Skene
      Pages: 116 - 125
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Keith R. Skene
      This paper addresses a key issue confronting ecological and evolutionary biology, namely the challenge of a cohesive approach to these fields given significant differences in the concepts and foundations of their study. Yet these two areas of scientific research are paramount in terms addressing the spatial and temporal dynamics and distribution of diversity, an understanding of which is needed if we are to resolve the current crisis facing the biosphere. The importance of understanding how nature responds to change is now of essential rather than of metaphysical interest as our planet struggles with increasing anthropogenic damage. Ecology and evolutionary biology can no longer remain disjointed. While some progress has been made in terms of synthetic thinking across these areas, this has often been in terms of bridge building, where thinking in one aspect is extended over to the other side. We review these bridges and the success or otherwise of such efforts. This paper then suggests that in order to move from a descriptive to a mechanistic understanding of the biosphere, we may need to re-evaluate our approach to the studies of ecology and evolutionary biology, finding a common denominator that will enable us to address the critical issues facing us, particularly in terms of understanding what drives change, what determines tempo and how communities function. Common ground, we argue, is essential if we are to comprehend how resilience operates in the natural world and how diversification can counter increasing extinction rates. This paper suggests that thermodynamics may provide a bridge between ecology and evolutionary biology, and that this will enable us to move forward with otherwise intractable problems.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.10.010
      Issue No: Vol. 85 (2017)
       
  • How do patch quality and spatial context affect invertebrate communities
           in a natural moss microlandscape'
    • Authors: Hendrik Trekels; Mario Driesen; Bram Vanschoenwinkel
      Pages: 126 - 135
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Hendrik Trekels, Mario Driesen, Bram Vanschoenwinkel
      Globally, moss associated invertebrates remain poorly studied and it is largely unknown to what extent their diversity is driven by local environmental conditions or the landscape context. Here, we investigated small scale drivers of invertebrate communities in a moss landscape in a temperate forest in Western Europe. By comparing replicate quadrats of 5 different moss species in a continuous moss landscape, we found that mosses differed in invertebrate density and community composition. Although, in general, richness was similar among moss species, some invertebrate taxa were significantly linked to certain moss species. Only moss biomass and not relative moisture content could explain differences in invertebrate densities among moss species. Second, we focused on invertebrate communities associated with the locally common moss species Kindbergia praelonga in isolated moss patches on dead tree trunks to look at effects of patch size, quality, heterogeneity and connectivity on invertebrate communities. Invertebrate richness was higher in patches under closed canopies than under more open canopies, presumably due to the higher input of leaf litter and/or lower evaporation. In addition, increased numbers of other moss species in the same patch seemed to promote invertebrate richness in K. praelonga, possibly due to mass effects. Since invertebrate richness was unaffected by patch size and isolation, dispersal was probably not limiting in this system with patches separated by tens of meters, or stochastic extinctions may be uncommon. Overall, we conclude that invertebrate composition in moss patches may not only depend on local patch conditions, in a particular moss species, but also on the presence of other moss species in the direct vicinity.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.10.003
      Issue No: Vol. 85 (2017)
       
  • Refuse dumps from leaf-cutting ant nests reduce the intensity of
           above-ground competition among neighboring plants in a Patagonian steppe
    • Authors: Alejandro G. Farji-Brener; María Natalia Lescano
      Pages: 136 - 140
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Alejandro G. Farji-Brener, María Natalia Lescano
      In arid environments, the high availability of sunlight due to the scarcity of trees suggests that plant competition take place mainly belowground for water and nutrients. However, the occurrence of soil disturbances that increase nutrient availability and thereby promote plant growth may enhance shoot competition between neighboring plants. We conducted a greenhouse experiment to evaluate the influence of the enriched soil patches generated by the leaf-cutting ant, Acromyrmex lobicornis, on the performance of the alien forb Carduus thoermeri (Asteraceae) under different intraspecific competition scenarios. Our results showed that substrate type and competition scenario affected mainly aboveground plant growth. As expected, plants growing without neighbors and in nutrient-rich ant refuse dumps showed more aboveground biomass than plants growing with neighbors and in nutrient-poor steppe soils. However, aboveground competition was more intense in nutrient-poor substrates: plants under shoot and full competition growing in the nutrient-rich ant refuse dumps showed higher biomass than those growing on steppe soils. Belowground biomass was similar among focal plants growing under different substrate type. Our results support the traditional view that increments in resource availability reduce competition intensity. Moreover, the fact that seedlings in this sunny habitat mainly compete aboveground illustrates how limiting factors may be scale-dependent and change in importance as plants grow.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.10.009
      Issue No: Vol. 85 (2017)
       
  • Modeling impacts of human footprint and soil variability on the potential
           distribution of invasive plant species in different biomes
    • Authors: Ji-Zhong Wan; Chun-Jing Wang; Fei-Hai Yu
      Pages: 141 - 149
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Ji-Zhong Wan, Chun-Jing Wang, Fei-Hai Yu
      Human footprint and soil variability may be important in shaping the spread of invasive plant species (IPS). However, until now, there is little knowledge on how human footprint and soil variability affect the potential distribution of IPS in different biomes. We used Maxent modeling to project the potential distribution of 29 IPS with wide distributions and long introduction histories in China based on various combinations of climatic correlates, soil characteristics and human footprint. Then, we evaluated the relative importance of each type of environmental variables (climate, soil and human footprint) as well as the difference in range and similarity of the potential distribution of IPS between different biomes. Human footprint and soil variables contributed to the prediction of the potential distribution of IPS, and different types of biomes had varying responses and degrees of impacts from the tested variables. Human footprint and soil variability had the highest tendency to increase the potential distribution of IPS in Montane Grasslands and Shrublands. We propose to integrate the assessment in impacts of human footprint and soil variability on the potential distribution of IPS in different biomes into the prevention and control of plant invasion.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.10.008
      Issue No: Vol. 85 (2017)
       
  • The role of biotic interactions in plant community assembly: What is the
           community species pool'
    • Authors: Eva Švamberková; Alena Vítová; Jan Lepš
      Pages: 150 - 156
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Eva Švamberková, Alena Vítová, Jan Lepš
      Differences in plant species composition between a community and its species pool are considered to reflect the effect of community filters. If we define the species pool as a set of species able to reach a site and form a viable population in a given abiotic environment (i.e. to pass the dispersal and abiotic filter), the difference in species composition should correspond to the effect of biotic interactions. However, most of the operational definitions of the species pool are based on co-occurrence patterns and thus also reflect the effect of biotic relationships, including definitions based on functional plant traits, Ellenberg indicator values or Beals index. We conducted two seed introduction experiments in an oligotrophic wet meadow with the aim of demonstrating that many species excluded, according to the above definitions, from a species pool are in fact able to establish there successfully if competition is removed. In sowing experiments, we studied the establishment and survival of species after the removal of competition (i.e. in artificial gaps) and in intact vegetation. We also investigated inter-annual variability of seed germination and seedling establishment and competitive exclusion of sown species. The investigated species also included those from very different habitats (i.e. species with very low corresponding Beals index or Ellenberg indicator values that were different from the target community weighted mean). Many of these species were able to grow in the focal wet meadow if competition was removed, but they did not establish and survive in the intact community. These species are thus not limited by abiotic conditions, but by the biotic filter. We also recorded a great inter-annual variability in seed germination and seedling establishment. Competitive exclusion of species with different ecological requirements could be quite fast (one and half seasons) in some species, but some non-resident species were able to survive several seasons; the resident species were able to persist in competition. Comparison of realized vegetation composition with the corresponding species pool greatly underestimates the potential impact of the biotic filter if the delimitation of the species pool is based on the realized niches of species and co-occurrence patterns.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.10.011
      Issue No: Vol. 85 (2017)
       
  • Nitrogen enrichment of host plants has mostly beneficial effects on the
           life-history traits of nettle-feeding butterflies
    • Authors: Susanne Kurze; Thilo Heinken; Thomas Fartmann
      Pages: 157 - 164
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Susanne Kurze, Thilo Heinken, Thomas Fartmann
      Butterflies rank among the most threatened animal groups throughout Europe. However, current population trends differ among species. The nettle-feeding butterflies Aglais io and Aglais urticae cope successfully with the anthropogenic land-use change. Both species are assumed to be pre-adapted to higher nitrogen contents in their host plant, stinging nettle (Urtica dioica). However, it is currently unknown, whether this pre-adaptation enables both Aglais species to cope successfully or even to benefit from the excessive nitrogen availabilities in nettles growing in modern farmlands. For this reason, this study focused on the response of both Aglais species to unfertilized nettles compared to nettles receiving 150 or 300 kg N ha−1 yr−1 (i.e., common fertilizer quantities of modern-day agriculture). Fertilized nettles were characterized by higher nitrogen concentrations and lower C:N ratios compared to the control group. In both Aglais species, the individuals feeding on fertilized nettles had higher survival rates, shorter larval periods and heavier pupae and, in A. urticae also longer forewings. All these trait shifts are beneficial for the individuals, lowering their risk to die before reproduction and increasing their reproductive potential. These responses agree with the well-accepted nitrogen-limitation hypothesis predicting a positive relationship between the nitrogen content of the diet and the performance of herbivorous insects. Furthermore, our findings suggest that the increasing abundance of both Aglais species may result not only from the increasing spread of nettles into the farmland but also from changes in their quality due to the eutrophication of the landscape during recent decades.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.11.005
      Issue No: Vol. 85 (2017)
       
  • Aposematism and crypsis are not enough to explain dorsal polymorphism in
           the Iberian adder
    • Authors: Fernando Martínez-Freiría; Guillem Pérez i de Lanuza; António A. Pimenta; Tiago Pinto; Xavier Santos
      Pages: 165 - 173
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Fernando Martínez-Freiría, Guillem Pérez i de Lanuza, António A. Pimenta, Tiago Pinto, Xavier Santos
      Aposematic organisms can show phenotypic variability across their distributional ranges. The ecological advantages of this variability have been scarcely studied in vipers. We explored this issue in Vipera seoanei, a species that exhibits five geographically structured dorsal colour phenotypes across Northern Iberia: two zigzag patterned (Classic and Cantabrica), one dorsal-strip patterned (Bilineata), one even grey (Uniform), and one melanistic (Melanistic). We compared predation rates (raptors and mammals) on plasticine models resembling each colour phenotype in three localities. Visual modelling techniques were used to infer detectability (i.e. conspicuousness) of each model type for visually guided predators (i.e. diurnal raptors). We hypothesize that predation rates will be lower for the two zigzag models (aposematism hypothesis) and that models with higher detectability would show higher predation rates (detectability hypothesis). Classic and Bilineata models were the most conspicuous, while Cantabrica and Uniform were the less. Melanistic presented an intermediate conspicuousness. Predation rate was low (3.24% of models) although there was variation in attack frequency among models. Zigzag models were scarcely predated supporting the aposematic role of the zigzag pattern in European vipers to reduce predation (aposematism hypothesis). From the non-zigzag models, high predation occurred on Bilineata and Melanistic models, and low on Uniform models, partially supporting our detectability hypothesis. These results suggest particular evolutionary advantages for non-zigzag phenotypes such as better performance of Melanistic phenotypes in cold environments or better crypsis of Uniform phenotypes. Polymorphism in V. seoanei may respond to a complex number of forces acting differentially across an environmental gradient.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.11.003
      Issue No: Vol. 85 (2017)
       
  • Lying in wait: Limiting factors on a low-density ungulate population and
           the latent traits that can facilitate escape from them
    • Authors: Kyle Joly; Tim Craig; Matthew D. Cameron; Adrian E. Gall; Mathew S. Sorum
      Pages: 174 - 183
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Kyle Joly, Tim Craig, Matthew D. Cameron, Adrian E. Gall, Mathew S. Sorum
      Predation, habitat, hunting, and environmental conditions have all been implicated as regulatory mechanisms in ungulate populations. The low-density equilibrium hypothesis predicts that in low-density populations, predators regulate their prey and that the population will not escape unless predation pressure is eased. We evaluated survival of adult and juvenile moose (Alces alces) in north-central Alaska to determine whether or not the population supported the hypothesis. We instrumented adult male and female moose with radiocollars and used aerial observations to track parturition and subsequent survival of juvenile moose. Generalized linear mixed-effects models were used to assess survival. Adult annual survival rates were high (∼89%), but may be negatively influenced by winter conditions. Migratory status did not affect moose survivorship or productivity. Approximately 60% of the calf crop died before 5 months of age. Productivity was significantly lower in the northern section of the study area where there is less high-quality habitat, suggesting that, even in this low-density population, nutrition could be a limiting factor. It appears that predation on young calves, winter weather, and nutritional constraints may be interacting to limit this population. Latent traits, such as overproduction of calves and migratory behavior, which do not currently enhance fitness, may persist within this population so that individuals with these traits can reap benefits when environmental conditions change.

      PubDate: 2017-11-18T04:59:04Z
      DOI: 10.1016/j.actao.2017.11.004
      Issue No: Vol. 85 (2017)
       
  • Ontogenetic stage, plant vigor and sex mediate herbivory loads in a
           dioecious understory herb
    • Authors: Sara Selaković; Vukica Vujić; Nemanja Stanisavljević; Živko Jovanović; Svetlana Radović; Dragana Cvetković
      Pages: 184 - 190
      Abstract: Publication date: Available online 14 November 2017
      Source:Acta Oecologica
      Author(s): Sara Selaković, Vukica Vujić, Nemanja Stanisavljević, Živko Jovanović, Svetlana Radović, Dragana Cvetković
      Plant-herbivore interactions can be mediated by plant apparency, defensive and nutritional quality traits that change through plant ontogeny, resulting in age-specific herbivory. In dioecious species, opposing allocation patterns in defense may lead to sex-biased herbivory. Here, we examine how onto stage and plant sex determine levels of herbivore damage in understory herb Mercurialis perennis under field conditions. We analyzed variation in plant size (height, total leaf area), physical (specific leaf area) and chemical (total phenolic and condensed tannins contents) defense, and nutritional quality (total water, soluble protein and nonstructural carbohydrate contents) during the shift from reproductive to post-reproductive stage. Furthermore, we explored correlations between the analyzed traits and levels of foliar damage. Post-reproductive plants had lower levels of chemical defense, and larger leaf area removed, in spite of having lower nutritive quality. Opposing patterns of intersexual differences were detected in protein and phenolic contents during reproductive stage, while in post-reproductive stage total leaf area was sexually dimorphic. Female-biased herbivory was apparent only after reproduction. Plant size parameters combined with condensed tannins content determined levels of foliar damage during post-reproductive stage, while the only trait covarying with herbivory in reproductive stage was total nonstructural carbohydrate content. Our results support claims of optimal defense theory – sensitive stage of reproduction was better defended. We conclude that different combinations of plant traits mediated interactions with herbivores in mature stages. Differences in reproductive allocation between the sexes may not immediately translate into different levels of damage, stressing the need for considering different ontogenetic stages when exploring sex bias in herbivory.

      PubDate: 2017-11-18T04:59:04Z
      DOI: 10.1016/j.actao.2017.11.006
      Issue No: Vol. 85 (2017)
       
  • Context dependence of acorn handling by the Algerian mouse (Mus spretus)
    • Authors: D. Gallego; T. Morán-López; I. Torre; Á. Navarro-Castilla; I. Barja; M. Díaz
      Pages: 1 - 7
      Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84
      Author(s): D. Gallego, T. Morán-López, I. Torre, Á. Navarro-Castilla, I. Barja, M. Díaz
      Perceived predation risk and competition for acorns are expected to affect scatter-hoarding decisions by Algerian mice (Mus spretus). We manipulated both factors by means of predator fecal scents and ungulate exclosures. We hypothesized that high-risk perception and ungulate presence would promote acorn dispersal. In the former case, it would stimulate acorn mobilization to safe microhabitats rather than in situ consumption. In the latter, increased competition for acorns would promote their storage for later consumption. We also expected that mice would adapt their foraging behavior to previous experience modulating the strength of these effects. In the presence of ungulates, mice focused their foraging activities on food acquisition at the expenses of vigilant behaviors. However, a more efficient foraging did not entail enhanced dispersal services. Lack of anti-predatory cover in tree surroundings may have deterred mice from transporting seeds outside canopies. Increased risk interacted with previous experience. In control trees (no predator odor), mice confidence increased throughout the night resulting in decreased vigilance and enhanced acorn mobilization rates. In contrast, in risky conditions (trees with predator odor) mice maintained a base-line vigilant behavior. Contrary to our expectations, increased risk did not result in higher acorn mobilization, but the opposite. Again, the scarcity of safe microhabitats for mobilization may have been the underlying cause of this behavior. Our results show that successful acorn dispersal depends, at least partly, on plant-animal relationships that are beyond the oak-rodent mutualism. Thus, any conservation policy aimed at restoring natural regeneration of oaks should take into account the interaction network in which oak-rodent encounters are embedded. In addition, they suggest that mice incorporate direct and indirect cues of risks (habitat structure) through recent experience. A better understanding of this process will improve our ability to incorporate such temporal and spatial variability in models of acorn dispersal.

      PubDate: 2017-07-24T02:06:49Z
      DOI: 10.1016/j.actao.2017.07.002
      Issue No: Vol. 84 (2017)
       
  • Temperature-dependent performance of competitive native and alien invasive
           plant species
    • Authors: Uhram Song
      Pages: 8 - 14
      Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84
      Author(s): Uhram Song
      To assess the likely impacts of environmental change, the responses of two well-known invasive plant species, native Pueraria lobata and alien Humulus japonicus, to differences in growth temperature were studied in South Korea. Habitat preferences, physiological responses such as photosynthetic rates and chlorophyll contents, growth rates, and nutrient contents were quantified for each species. A competition experiment was conducted to evaluate the temperature preferences of the two species. All results indicated that the alien species H. japonicus can take advantage of elevated temperatures (35 °C) to enhance its competitive advantage against the native species P. lobata. While H. japonicus took advantage of elevated temperatures and preferred high-temperature areas, P. lobata showed reduced performance and dominance in high-temperature areas. Therefore, in future, due to global warming and urbanization, there are possibilities that H. japonicus takes advantage of elevated temperature against P. lobata that could lead to increased H. japonicus coverage over time. Therefore, consistent monitoring of both species especially where P. lobata is dominated are required because both species are found in every continents in the world. Controlling P. lobata requires thorough inspection of H. japonicus presence of the habitat in advance to prevent post P. lobata management invasion of H. japonicus.

      PubDate: 2017-08-28T04:23:16Z
      DOI: 10.1016/j.actao.2017.08.001
      Issue No: Vol. 84 (2017)
       
  • Seasonality, diaspore traits and the structure of plant-frugivore networks
           in Neotropical savanna forest
    • Authors: Adriano Antonio Brito Darosci; Emilio M. Bruna; José Carlos Motta-Junior; Cristiane da Silva Ferreira; John Gilman Blake; Cássia Beatriz Rodrigues Munhoz
      Pages: 15 - 22
      Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84
      Author(s): Adriano Antonio Brito Darosci, Emilio M. Bruna, José Carlos Motta-Junior, Cristiane da Silva Ferreira, John Gilman Blake, Cássia Beatriz Rodrigues Munhoz
      Complex frugivory networks are common in heterogeneous environments, but how the structure of those networks varies due to seasonality and other environmental factors remains unclear. For example, seasonal variation in rainfall can influence fruit production and diaspore characteristics, which could alter the quantity and quality of resources available to different animals in the network and, hence, network structure. We investigated how a frugivory network varied seasonally in Brazilian savanna (Cerrado), where there are well-defined dry and wet seasons and fructification mainly during the rainy season for most tree species. We recorded fruit consumption by animals during the dry and wet seasons in two different gallery forests and used these data to test the hypotheses that connectance, links per species and nestedness would be higher in the dry season than rainy season due to low available food in the former that would be consumed by various species of frugivores. Concomitantly, we also measured seed width and lipid content from diaspores of the fruiting trees to determine if these characteristics influenced interaction properties between fruiting trees and frugivores. Among the measured network parameters, connectance, links per species and specialization varied between seasons in one site but not in the other, indicating that seasonal variation in networks is not necessarily consistent over time or space. The number of tree species with small diaspores with high lipid content differed between seasons, and those characteristics were key factors increasing the interaction parameter of fruiting trees. We suggest that network stability between seasons may be related to local frugivore diversity, resource availability, and fruit quality.

      PubDate: 2017-08-28T04:23:16Z
      DOI: 10.1016/j.actao.2017.08.003
      Issue No: Vol. 84 (2017)
       
  • Range expansion potential of two co-occurring invasive vines to marginal
           habitats in Turkey
    • Authors: Shahid Farooq; Sonnur Tad; Huseyin Onen; Hikmet Gunal; Ugur Caldiran; Cumali Ozaslan
      Pages: 23 - 33
      Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84
      Author(s): Shahid Farooq, Sonnur Tad, Huseyin Onen, Hikmet Gunal, Ugur Caldiran, Cumali Ozaslan
      Niche distribution models accurately predict the potential distribution range of invasive plants into new habitats based on their climatic requirements in the native regions. However, these models usually ignore the marginal habitats which can limit the distribution of exotic plants. We therefore tested the seedling survival, growth and nutrient acquisition capabilities of two co-occurring invasive vines [Persicaria perfoliata (L.) H. Gross and Sicyos angulatus L.] in three different manipulative greenhouse experiments to infer their range expansion potential to marginal habitats in Turkey. First experiment included five different moisture availability regimes (100, 75, 50, 25 and 12.5% available water), second experiment consisted of four different salinity levels (0, 3, 6 and 12 dSm−1 soil salinity) and third experiment had four different soil textures (clay-1, clay-2, sandy loam and silt-clay-loam). Seedling mortality was only observed under extreme moisture deficiency in both plant species, while most of the transplanted seedlings of both species did not survive under 6 and 12 dSm−1 salinity levels. Soil textures had no effect on seedling survival. POLPE better tolerated low moisture availability and high salinity compared to SIYAN. Biomass production in both plant species was linearly reduced with increasing salinity and moisture deficiency. SIYAN invested more resources towards shoot, accumulated higher K and P, whereas POLPE maintained higher root-to-shoot ratio under all experimental conditions. Both plant species employed different strategies to cope with adverse environmental conditions, but failed to persist under high soil salinity and moisture deficiency. Our study suggest that both plant species have limited potential of range expansion to marginal habitats and will be limited to moist and humid areas only. Therefore, further research activities should be concentrated in these regions to develop effective management strategies against both species.

      PubDate: 2017-08-30T04:24:42Z
      DOI: 10.1016/j.actao.2017.08.004
      Issue No: Vol. 84 (2017)
       
  • Prey availability affects territory size, but not territorial display
           behavior, in green anole lizards
    • Authors: Chelsea M. Stehle; Andrew C. Battles; Michelle N. Sparks; Michele A. Johnson
      Pages: 41 - 47
      Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84
      Author(s): Chelsea M. Stehle, Andrew C. Battles, Michelle N. Sparks, Michele A. Johnson
      The availability of food resources can affect the size and shape of territories, as well as the behaviors used to defend territories, in a variety of animal taxa. However, individuals within a population may respond differently to variation in food availability if the benefits of territoriality vary among those individuals. For example, benefits to territoriality may differ for animals of differing sizes, because larger individuals may require greater territory size to acquire required resources, or territorial behavior may differ between the sexes if males and females defend different resources in their territories. In this study, we tested whether arthropod abundance and biomass were associated with natural variation in territory size and defense in insectivorous green anole lizards, Anolis carolinensis. Our results showed that both male and female lizards had smaller territories in a habitat with greater prey biomass than lizards in habitats with less available prey, but the rates of aggressive behaviors used to defend territories did not differ among these habitats. Further, we did not find a relationship between body size and territory size, and the sexes did not differ in their relationships between food availability and territory size or behavioral defense. Together, these results suggest that differences in food availability influenced male and female territorial strategies similarly, and that territory size may be more strongly associated with variation in food resources than social display behavior. Thus, anole investment in the behavioral defense of a territory may not vary with territory quality.

      PubDate: 2017-09-06T04:57:55Z
      DOI: 10.1016/j.actao.2017.08.008
      Issue No: Vol. 84 (2017)
       
  • Modelling the spatial baseline for amphibian conservation in West Africa
    • Authors: Johannes Penner; Moritz Augustin; Mark-Oliver Rödel
      Abstract: Publication date: Available online 21 December 2017
      Source:Acta Oecologica
      Author(s): Johannes Penner, Moritz Augustin, Mark-Oliver Rödel
      To answer questions such as whether the existing network of protected areas is sufficient, conservation needs data covering complete taxonomic groups and large geographic areas. However, most distributional data sets are either coarse, patchy and/or based solely on expert opinion which is often hard to verify. In addition, not all regions are equally well studied. For example sub-Saharan Africa remains comparatively under-sampled for most taxa, especially Central and Western Africa. However, these regions contain many threatened species, including a high diversity of highly threatened vertebrates - amphibians. To fill this knowledge gap, we extrapolated species occurrence records (n = 15,944) on a 30 arc-seconds grid for most known West African amphibian taxa (92%), using environmental niche modelling and employing relevant environmental parameters (climate, vegetation, elevation & distance to rivers). We provide, for the first time, a fine scale distribution map of amphibian alpha diversity for the entire West African region. Already known centres of high biodiversity were confirmed (e.g. south-western Ghana and south-eastern Côte d’Ivoire) and new ones were identified (e.g. northern Liberia and the borders of Liberia with Guinea and Sierra Leone). Diversity analyses focusing on unique amphibians, i.e. threatened, endemic and evolutionary distinct species', revealed that areas of high diversity also contained many high conservation-priority species. Herewith, we offer a comprehensive baseline for identifying those areas which are important for amphibian conservation for one of the most periled regions on the continent. Those areas of high diversity were only partly in accordance with previous analyses such as the hotspot definitions, the ecoregion analyses, or analyses of other taxa, highlighting the added new value of our approach. The most outstanding areas of amphibian diversity were only partly covered by the existing network of protected areas. Thus there is an urgent need to devise a regional conservation concept to protect West African amphibians from extinction.
      Graphical abstract image

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.018
       
  • Geographic variation of fruit scents in a dispersion mutualism, the case
           of Ficus lutea
    • Authors: Catherine C.L. Soler; Bertrand Schatz; Jean-Marie Bessière; Martine Hossaert-McKey
      Abstract: Publication date: Available online 7 December 2017
      Source:Acta Oecologica
      Author(s): Catherine C.L. Soler, Bertrand Schatz, Jean-Marie Bessière, Martine Hossaert-McKey
      Chemical mediation is often involved in interactions between plants and animals, as in pollination and in seed dispersion mutualisms. Extensive investigation has been done in floral scents and on their interspecific and intraspecific variations, but similar research on fruit scent remains poorly explored and only focused on interspecific variations. We investigated in this study the intraspecific variations of volatile bouquet emitted by mature fruits of Ficus lutea, in two sites within its wide distribution range, i.e. in South Africa and in Madagascar. We demonstrated a clear geographic variation in the volatile bouquet emitted by ripe figs in these two study sites, especially due to the presence of sesquiterpenes in Madagascan bouquets, while scents present at both sites high amounts of fatty acid derivatives. We discuss here different possible explanations for such variations in fruit scents, potentially resulting from insular and/or geographic isolation. This novel result of an intraspecific variation linked to fig seed dispersion serves to increase our knowledge of the role of scents in seed dispersal mutualisms.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.014
       
  • Keep it simple' Dispersal abilities can explain why species range
           sizes differ, the case study of West African amphibians
    • Authors: Johannes Penner; Mark-Oliver Rödel
      Abstract: Publication date: Available online 6 December 2017
      Source:Acta Oecologica
      Author(s): Johannes Penner, Mark-Oliver Rödel
      A well-known positive correlation between niche breadth and range size exists across a number of animal and plant taxa. A relatively more simple explanation, range size being connected to differing dispersal abilities, was recently presented for passerine birds. Unfortunately, respective datasets are not easily available for other taxonomic groups. We circumvented this problem by developing a simple dispersal index, incorporating niche information (body size, litter size, preferred habitats of adults and offspring, ecotype of adults) which can be collected straightforwardly for most animal taxa. We tested this dispersal index for species which are generally considered poor dispersers, amphibians. Our results from West Africa revealed a positive correlation between the dispersal index and range size (p < 0.001). Our index can easily be transferred to and tested with other taxa. Furthermore, our results suggest one possible way of integrating information on dispersal abilities in niche modelling (distribution modelling) processes which assess the impact of climate change on future species distributions.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.011
       
  • Spatial variation in pollinator gall failure within figs of the
           gynodioecious Ficus hirta
    • Authors: Hui Yu; Stephen G. Compton; Lanfen Wu
      Abstract: Publication date: Available online 1 December 2017
      Source:Acta Oecologica
      Author(s): Hui Yu, Stephen G. Compton, Lanfen Wu
      Figs, the inflorescences of Ficus species (Moraceae), contain numerous uni-ovulate flowers. Male trees of gynodioecious Ficus have figs that support development of pollinator fig wasp offspring (Agaonidae) and rarely produce seeds. Pollinator larvae develop inside galled ovules that expand rapidly after eggs are laid to fill the available space. Galls that fail to support successful larval development can be abundant and failures may influence oviposition behavior and modify realized offspring sex ratios. We examined pollinator reproductive success in figs of the Asian Ficus hirta where we had allowed entry by either one or two foundresses and prevented attack by parasitoids. At the developmental stage when adult offspring were about to emerge from their galls, we recorded where in the figs their galls were located, the distributions of sons and daughters in the galls and whether galls that developed closest to the periphery of the figs were more likely to fail. Foundress number had an effect on gall location, but not total offspring numbers. No spatial variation in the distribution of male and female adult offspring was detected. Overall, over 25% of the galled ovaries failed to support offspring development, and failure rates were independent of foundress number. More peripheral galls were more likely to fail in figs entered by two foundresses. Gall location in gynodioecious figs is determined largely by the extent to which their basal pedicels expand after galling. Competition for nutrients between galls, with those developing shorter pedicels being at a disadvantage, may explain the results. If pedicel length is related to timing of oviposition, then pollinator eggs laid later are less likely to survive.

      PubDate: 2017-12-27T04:19:11Z
      DOI: 10.1016/j.actao.2017.11.009
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85


      PubDate: 2017-12-27T04:19:11Z
       
  • Rush hour at the Museum – Diversification patterns provide new clues for
           the success of figs (Ficus L., Moraceae)
    • Authors: Sam Bruun-Lund; Brecht Verstraete; Finn Kjellberg; Nina Rønsted
      Abstract: Publication date: Available online 13 November 2017
      Source:Acta Oecologica
      Author(s): Sam Bruun-Lund, Brecht Verstraete, Finn Kjellberg, Nina Rønsted
      Tropical rainforests harbour much of the earth's plant diversity but little is still known about how it evolved and why a small number of plant genera account for the majority. Whether this success is due to rapid turnover or constant evolution for these hyper-diverse plant genera is here tested for the species-rich genus Ficus L. (figs). The pan-tropical distribution of figs makes it an ideal study group to investigate rainforest hyper-diversification patterns. Using a recently published, dated and comprehensive phylogenetic hypothesis, we infer that figs are an old lineage that gradually accumulated species and exhibits very low extinction rates, which corresponds to the ‘museum model’ of evolution. Overall, no major significant shifts in evolutionary dynamics are detected, yet two shifts with lower probability are found. Hemi-epiphytism, monoecy, and active pollination are traits that possibly are associated with the hyper-diversity found in figs, making it possible for the plants to occupy new niches followed by extensive radiation over evolutionary time scales. Figs possess unique diversification patterns compared to other typical rainforest genera.

      PubDate: 2017-11-18T04:59:04Z
      DOI: 10.1016/j.actao.2017.11.001
       
  • Comparison of the antennal sensilla of females of four fig-wasps
           associated with Ficus auriculata
    • Authors: Pei Yang; Zong-bo Li; Da-rong Yang; Yan-qiong Peng; Finn Kjellberg
      Abstract: Publication date: Available online 7 November 2017
      Source:Acta Oecologica
      Author(s): Pei Yang, Zong-bo Li, Da-rong Yang, Yan-qiong Peng, Finn Kjellberg
      A comparison was performed of the antennal sensilla of females of four chalcid wasp species Ceratosolen emarginatus Mayr, 1906, Sycophaga sp., Philotrypesis longicaudata Mayr, 1906, and Sycoscapter roxburghi Joseph, 1957, which are specific and obligatory associated with Ficus auriculata (Lour, 1790). The four species exhibit different oviposition strategies in the fig ovules where their offspring hatch and develop. Antennal sensilla morphology was evaluated using scanning electron microscopy. Females of the four species present 11 morphologically similar types of sensilla: trichoid sensilla, sensilla obscura, chaetica sensilla 1 and 2, which all have mechanosensory functions; uniporous basiconic sensilla, which are presumably contact chemosensilla; basiconic capitate peg sensilla, coeloconic sensilla 1, multiporous basiconic and placoid sensilla, which may be regarded as olfactory sensilla, and coeloconic sensilla 2 and 3, which are presumed to be proprioreceptors or pressure receptors. The four species have significant differences in the abundance and arrangement of trichoid sensilla and chaetica sensilla 1 on the flagellum. The coeloconic sensilla and sensilla obscura only occur on the antennae of C. emarginatus that enter figs. The chemosensilla which are presumably involved in host discrimination, i.e., basiconic sensilla, multiporous placoid sensilla and basiconic capitate peg sensilla, are similar in shape and configuration, although they present some differences in abundance. These findings provide practical information on the adaptations of fig wasps and the relationship between multisensory antennae and functions in fig wasp behaviour.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.11.002
       
  • Ovipositor morphology correlates with life history evolution in agaonid
           fig wasps
    • Authors: Larissa Galante Elias; Finn Kjellberg; Fernando Henrique Antoniolli Farache; Eduardo A.B. Almeida; Jean-Yves Rasplus; Astrid Cruaud; Yan-Qiong Peng; Da-Rong Yang; Rodrigo Augusto Santinelo Pereira
      Abstract: Publication date: Available online 7 November 2017
      Source:Acta Oecologica
      Author(s): Larissa Galante Elias, Finn Kjellberg, Fernando Henrique Antoniolli Farache, Eduardo A.B. Almeida, Jean-Yves Rasplus, Astrid Cruaud, Yan-Qiong Peng, Da-Rong Yang, Rodrigo Augusto Santinelo Pereira
      The high adaptive success of parasitic Hymenoptera might be related to the use of different oviposition sites, allowing niche partitioning among co-occurring species resulting in life history specialization and diversification. In this scenario, evolutionary changes in life history and resources for oviposition can be associated with changes in ovipositor structure, allowing exploitation of different substrates for oviposition. We used a formal phylogenetic framework to investigate the evolution of ovipositor morphology and life history in agaonid wasps. We sampled 24 species with different life histories belonging to all main clades of Agaonidae including representatives of all described genera of non-pollinating fig wasps (NPFW). Our results show an overall correlation between ovipositor morphology and life history in agaonid fig wasps. Ovipositor morphologies seem to be related to constraints imposed by features of the oviposition sites since ovipositor morphology has experienced convergent evolution at least four times in Sycophaginae (Agaonidae) according to the resource used. Non-galling species have more distantly spaced teeth with uneven spacing, as opposed to the observed morphology of galling species. Our results suggest that the ancestral condition for ovipositor morphology was most likely the presence of one or two apical teeth. Regarding life history, ovary galling species that oviposit in receptive figs possibly represent the ancestral condition. Different ovipositor characteristics allow exploitation of new niches and may be related to resource partitioning and species co-existence in the fig-fig wasp system.

      PubDate: 2017-11-11T03:44:26Z
      DOI: 10.1016/j.actao.2017.10.007
       
  • The role of non-fig-wasp insects on fig tree biology, with a proposal of
           the F phase (Fallen figs)
    • Authors: Luciano Palmieri; Rodrigo Augusto Santinelo Pereira
      Abstract: Publication date: Available online 23 October 2017
      Source:Acta Oecologica
      Author(s): Luciano Palmieri, Rodrigo Augusto Santinelo Pereira
      The two seminal papers by Galil and Eisikowitch describing the development of Ficus flowers and their sycophilous wasps (i.e., phases A-E) have been adopted in several ecological and evolutionary studies on a wide range of fig tree-insect interactions. Their classification, however, is not inclusive enough to encompass all the diversity of insects associated with the fig development, and the impact of this fauna on the fig-fig wasp mutualism is still unexplored. Here we describe the life history of the non-fig-wasp insects and propose an additional phase to fig-development classification, the F phase (Fallen figs). These figs are not consumed by frugivores while still on the parent tree, fall to the ground and turn into a resource for a diverse range of animals. To support the relevance of the F phase, we summarized a 5-years-period of field observations made on different biomes in three continents. Additionally, we compiled data from the literature of non-fig-wasp insects including only insects associated with inflorescences of wild fig tree species. We report 129 species of non-fig-wasp insects feeding on figs; they colonize the figs in different phases of development and some groups rely on the fallen figs to complete their life cycles. Their range of interaction varies from specialists – that use exclusively fig pulp or fig seeds in their diets – to generalists, opportunists and parasitoids species. The formalization of this additional phase will encourage new studies on fig tree ecology and improve our knowledge on the processes that affect the diversification of insects. It will also help us to understand the implications this fauna may have had on the origin and maintenance of mutualistic interactions.

      PubDate: 2017-11-05T01:03:51Z
      DOI: 10.1016/j.actao.2017.10.006
       
  • Laticifer distribution in fig inflorescence and its potential role in the
           fig-fig wasp mutualism
    • Authors: Cristina Ribeiro Marinho; Rodrigo Augusto Santinelo Pereira; Yan-Qiong Peng; Simone Pádua Teixeira
      Abstract: Publication date: Available online 17 October 2017
      Source:Acta Oecologica
      Author(s): Cristina Ribeiro Marinho, Rodrigo Augusto Santinelo Pereira, Yan-Qiong Peng, Simone Pádua Teixeira
      Although in Moraceae the presence of laticifers is considered to be a synapomorphy, little is known about the distribution and morphology of this type of secretory structure in the reproductive organs of its species. Ficus, the largest genus of Moraceae, is characterized by an inflorescence known as syconium and by an obligate mutualistic interaction with pollinating wasps. The objectives of the present study were to evaluate the distribution and morphology of laticifers in syconia of 36 species belonging to different Ficus sections and to survey traits of taxonomic and adaptive value for the group. Syconia containing flowers in a receptive state were collected, fixed and processed for anatomical analysis. All species studied have branched laticifers distributed in the syconium receptacle, in the ostiolar bracts and in the pedicel of staminate flowers. Almost all species show laticifers in the pedicel of shorter-styled flowers. Laticifers also occur in the pedicel of longer-styled flowers in most Ficus sections, except F. curtipes (Conosycea section) and more than 75% of the studied species of the Americanae section. Laticifers are observed in the sepals of 25 of the 36 species studied and occasionally in the pistil. The presence of laticifers in the pedicel of shorter-style flowers and its absence in the pistil suggest that the distribution of this secretory structure in the fig flower was selected by pressures imposed by the fig-fig wasp mutualism. The laticifers in the pedicel of shorter-styled flowers may confer protection to the developing wasp larvae against natural enemies. However, the absence of laticifers in the pistil of most Ficus species studied was probably selected by the mutualistic relationship with the agaonid pollinating wasps since the latex could interfere with oviposition through the style, with the larval development of the pollinating fig wasps, and the emergence of pollinator offspring from their galls.

      PubDate: 2017-11-05T01:03:51Z
      DOI: 10.1016/j.actao.2017.10.005
       
  • Understanding the influence of non-wealth factors in determining bushmeat
           consumption: Results from four West African countries
    • Authors: Luca Luiselli; Emmanuel M. Hema; Gabriel Hoinsoudé Segniagbeto; Valy Ouattara; Edem A. Eniang; Massimiliano Di Vittorio; Nioking Amadi; Gnoumou Parfait; Nic Pacini; Godfrey C. Akani; Djidama Sirima; Wendengoudi Guenda; Barineme B. Fakae; Daniele Dendi; John E. Fa
      Abstract: Publication date: Available online 16 October 2017
      Source:Acta Oecologica
      Author(s): Luca Luiselli, Emmanuel M. Hema, Gabriel Hoinsoudé Segniagbeto, Valy Ouattara, Edem A. Eniang, Massimiliano Di Vittorio, Nioking Amadi, Gnoumou Parfait, Nic Pacini, Godfrey C. Akani, Djidama Sirima, Wendengoudi Guenda, Barineme B. Fakae, Daniele Dendi, John E. Fa
      The meat of wild animals (bushmeat) is consumed extensively in many tropical regions. Over the past few decades bushmeat consumption has greatly increased, threatening the survival of some hunted species and the supply of animal protein to countless numbers of people. Understanding patterns of bushmeat consumption is thus vital to ensure the sustainable use of this resource. Although the economic drivers of bushmeat consumption have been well studied, non-wealth correlates have been poorly considered. Here, we analyse how variables such as age and gender may influence bushmeat consumption in four West African countries, within the Guinean forests (Togo and Nigeria) and Sahel (Burkina Faso and Niger). We interviewed a total of 2453 persons (1253 urban, 1200 in rural areas) to determine frequency of consumption of bushmeat as well as the main species eaten. We found significant differences in bushmeat consumption between rural and urban areas in all four countries. In particular, the proportion of persons not consuming any bushmeat was highest in urban areas. Gender differences in bushmeat consumption were not generally important but young people consistently avoided eating bushmeat, especially in Togo and Nigeria, and in urban areas. The complicated interplay between tradition and evolution of social systems (especially the trends towards westernization) may explain the different perceptions that people may have towards consuming bushmeat in the four studied countries. In addition, we found considerable variation in types of bushmeat eaten, with antelopes and large rodents eaten by the great majority of interviewees, but bats, monkeys, and snakes being avoided, especially in urban settlements.

      PubDate: 2017-11-05T01:03:51Z
      DOI: 10.1016/j.actao.2017.10.002
       
  • Can fine-scale post-pollination variation of fig volatile compounds
           explain some steps of the temporal succession of fig wasps associated with
           Ficus racemosa'
    • Authors: Magali Proffit; Jean-Marie Bessière; Bertrand Schatz; Martine Hossaert-McKey
      Abstract: Publication date: Available online 12 October 2017
      Source:Acta Oecologica
      Author(s): Magali Proffit, Jean-Marie Bessière, Bertrand Schatz, Martine Hossaert-McKey
      Volatile organic compounds (VOCs) emitted by flowers play an essential role in mediating the attraction of pollinators. However, they also attract other species exploiting resources associated with flowers. For instance, VOCs emitted by figs play a major role in encounters between Ficus spp., their mutualistic pollinating wasps, and all the members of the community of non-pollinating fig wasps (NPFWs) that exploit the mutualistic interaction. Because pollinators might be in limited supply for a tree bearing many inflorescences, the plant might maximize its individual reproductive success by reducing the attractiveness of inflorescences once they are pollinated, so that pollinators orient only towards the tree's unpollinated figs. Changes in VOCs emission that bring this about could represent an important cue for NPFWs that exploit particular stages of fig development. In this study, by monitoring precisely the presence of fig-associated wasps on figs of F. racemosa, a common widespread fig species, we demonstrated that 4–5 days and 15 days following pollination represent two critical transitional steps in the succession of different wasp species. Then, focusing on the first one of these transitional steps, by investigating the composition of fig VOCs at receptivity and from 1 to 5 days following pollination, we detected progressive quantitative and qualitative variation of floral scent following pollination. These changes are significant at 5 days following pollination. The qualitative changes are mainly due to an increase in the relative proportions of two monoterpenes (α-pinene and limonene). These variations of the floral VOCs following pollination could explain why pollinating wasps stop visiting figs very shortly after the first pollinators enter receptive figs. They also possibly explain the succession of non-pollinating wasps on the figs following pollination.

      PubDate: 2017-10-14T03:59:07Z
      DOI: 10.1016/j.actao.2017.08.009
       
  • Relationships between soil parameters and vegetation in abandoned terrace
           fields vs. non-terraced fields in arid lands (Lanzarote, Spain): An
           opportunity for restoration
    • Authors: Silvia Alfredo; Reyes-Betancort Marisa Tejedor Francisco
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): José Ramón Arévalo, Silvia Fernández-Lugo, J. Alfredo Reyes-Betancort, Marisa Tejedor, Concepción Jiménez, Francisco J. Díaz
      Over 90% of terraced fields have been abandoned on the island of Lanzarote in the last 40 years. The present work analyses the effects of abandonment on the soil and vegetation recovery of terraced field agroecosystems by comparing them with adjacent non-terraced fields in Lanzarote, Canary Islands (Spain). This information is necessary to take the appropriate management actions to achieve goals such as soil protection and biodiversity conservation. Results indicate that terraced fields display better soil quality than non-terraced ones, as shown by the significant differences found in parameters such as SAR, exchangeable Na, CaCO3, B content, moisture content or soil depth. Moreover, the terraced fields' plant community has more species similarities with the native plant community when compared with non-terraced areas. Owing to characteristics such as deeper soils, more water capacity, lower salinity and less sodic soils, terraced soils provide better conditions for passive restoration of both soil and vegetation. Therefore, the recovery and maintenance of wall structures and revegetation with native/endemic species are proposed to promote the restoration of native systems and preserve a landscape with cultural and aesthetic value.

      PubDate: 2017-10-08T03:34:48Z
       
  • Seed-deposition and recruitment patterns of Clusia species in a disturbed
           tropical montane forest in Bolivia
    • Authors: Francisco Saavedra; Isabell Hensen Amira Apaza Quevedo Eike Lena Neuschulz
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Francisco Saavedra, Isabell Hensen, Amira Apaza Quevedo, Eike Lena Neuschulz, Matthias Schleuning
      Spatial patterns of seed dispersal and recruitment of fleshy-fruited plants in tropical forests are supposed to be driven by the activity of animal seed dispersers, but the spatial patterns of seed dispersal, seedlings and saplings have rarely been analyzed simultaneously. We studied seed deposition and recruitment patterns of three Clusia species in a tropical montane forest of the Bolivian Andes and tested whether these patterns changed between habitat types (forest edge vs. forest interior), distance to the fruiting tree and consecutive recruitment stages of the seedlings. We recorded the number of seeds deposited in seed traps to assess the local seed-deposition pattern and the abundance and distribution of seedlings and saplings to evaluate the spatial pattern of recruitment. More seeds were removed and deposited at the forest edge than in the interior. The number of deposited seeds decreased with distance from the fruiting tree and was spatially clustered in both habitat types. The density of 1-yr-old seedlings and saplings was higher at forest edges, whereas the density of 2-yr-old seedlings was similar in both habitat types. While seedlings were almost randomly distributed, seeds and saplings were spatially clustered in both habitat types. Our findings demonstrate systematic changes in spatial patterns of recruits across the plant regeneration cycle and suggest that the differential effects of biotic and abiotic factors determine plant recruitment at the edges and in the interior of tropical montane forests. These differences in the spatial distribution of individuals across recruitment stages may have strong effects on plant community dynamics and influence plant species coexistence in disturbed tropical forests.

      PubDate: 2017-10-08T03:34:48Z
       
  • Cone and seed traits of two Juniperus species influence roles of
           frugivores and scatter-hoarding rodents as seed dispersal agents
    • Authors: Lindsay Dimitri; William Longland Stephen Vander Wall
      Abstract: Publication date: November 2017
      Source:Acta Oecologica, Volume 85
      Author(s): Lindsay A. Dimitri, William S. Longland, Stephen B. Vander Wall
      Seed dispersal in Juniperus is generally attributed to frugivores that consume the berry-like female cones. Some juniper cones are fleshy and resinous such as those of western juniper (Juniperus occidentalis), while others are dry and leathery such as those of Utah juniper (J. osteosperma). Rodents have been recorded harvesting Juniperus seeds and cones but are mostly considered seed predators. Our study sought to determine if rodents play a role in dispersal of western and Utah juniper seeds. We documented rodent harvest of cones and seeds of the locally-occurring juniper species and the alternate (non-local) juniper species in removal experiments at a western juniper site in northeastern California and a Utah juniper site in western Nevada. Characteristics of western and Utah juniper cones appeared to influence removal, as cones from the local juniper species were preferred at both sites. Conversely, removal of local and non-local seeds was similar. Piñon mice (Peromyscus truei) were responsible for most removal of cones and seeds at both sites. We used radioactively labeled seeds to follow seed fate and found many of these seeds in scattered caches (western juniper: 415 seeds in 82 caches, 63.0% of seeds found; Utah juniper: 458 seeds in 127 caches, 39.5% of seeds found) most of which were attributed to piñon mice. We found little evidence of frugivores dispersing Utah juniper seeds, thus scatter-hoarding rodents appear to be the main dispersal agents. Western juniper cones were eaten by frugivores, and scatter-hoarding is a complimentary or secondary form of seed dispersal. Our results support the notion that Utah juniper has adapted to xeric environments by conserving water through the loss of fleshy fruits that attract frugivores and instead relies on scatter-hoarding rodents as effective dispersal agents.

      PubDate: 2017-10-08T03:34:48Z
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84


      PubDate: 2017-09-24T01:57:02Z
       
  • The potential of military training areas for bird conservation in a
           central European landscape
    • Authors: Reif
      Abstract: Publication date: October 2017
      Source:Acta Oecologica, Volume 84
      Author(s): Ondřej Bušek, Jiří Reif
      European biodiversity has suffered from serious declines during the past few decades, with alterations of land use practices resulting in a loss of fine-scale habitat heterogeneity being a dominant driver. This heterogeneity was maintained by extensive landscape management, which has gradually been replaced by either intensive exploitation or land abandonment. It has been suggested that military training can generate habitat heterogeneity that may support the existence of species of conservation concern, but studies rigorously testing the real importance of military training areas for biodiversity are lacking. Here we address this issue by analyses of two datasets. First, we compared land cover classes between all large military training areas (MTAs) and surrounding control areas (CAs) of the same size in the Czech Republic using multivariate redundancy analysis. We found that the difference in land cover between MTAs and CAs was significant and represented the strongest gradient in land cover classes: from various farmland and artificial habitats typical for CAs to forest and scrubland-grassland mosaic typical for MTAs. Second, we selected one of these areas and compared bird species richness between the MTA and the nearby CA using generalized linear mixed effects models. We found that the number of species of conservation concern was significantly higher in the MTA than in the CA. With respect to habitats, bird species richness was significantly higher in the MTA than in the CA for open habitats, but not for forest habitats. Our results are thus consistent with the view that military training creates areas that are different from the surrounding landscape in terms of land cover, and that this difference translates to a suitability for species of conservation concern. It is remarkable that the positive influence of military training is confined to open habitats, which are subject to the most intensive military activities and also suffer the highest degree of deterioration in European landscapes.

      PubDate: 2017-09-06T04:57:55Z
       
 
 
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