for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3042 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Showing 1 - 200 of 3042 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 17, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 81, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 23, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, 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: 328, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
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   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 206, 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: 9, 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: 23, 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: 3)
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: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 128, 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: 16, 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: 25, 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: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 20, 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: 25, 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 Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, 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: 10, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, 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 Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 40, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 40, 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: 48, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
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: 12)
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: 21, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
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: 35, 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: 4)
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: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, 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 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: 25, 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: 7, 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: 19, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 59)
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: 2, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 340, 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: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 30, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 15)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 43, 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: 309, 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: 8, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 400, 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: 30, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 38, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 50, 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: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 6)
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  
Algal Research     Partially Free   (Followers: 8, 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)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 7, 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: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 48, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 44, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 36, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 16, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 30, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 24, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 34, 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: 179, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 55, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
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: 23, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 24, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 33, 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: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 55, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 9)
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: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 160, 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: 11)
Anesthésie & Réanimation     Full-text available via subscription  
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  
Animal Behaviour     Hybrid Journal   (Followers: 153, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Journal Cover Acta Oecologica
  [SJR: 0.915]   [H-I: 53]   [9 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1146-609X
   Published by Elsevier Homepage  [3042 journals]
  • The effect of altitude, patch size and disturbance on species richness and
           density of lianas in montane forest patches
    • Authors: Dharmalingam Mohandass; Mason J. Campbell; Alice C. Hughes; Christos Mammides; Priya Davidar
      Pages: 1 - 14
      Abstract: Publication date: August 2017
      Source:Acta Oecologica, Volume 83
      Author(s): Dharmalingam Mohandass, Mason J. Campbell, Alice C. Hughes, Christos Mammides, Priya Davidar
      The species richness and density of lianas (woody vines) in tropical forests is determined by various abiotic and biotic factors. Factors such as altitude, forest patch size and the degree of forest disturbance are known to exert strong influences on liana species richness and density. We investigated how liana species richness and density were concurrently influenced by altitude (1700–2360 m), forest patch size, forest patch location (edge or interior) and disturbance intensity in the tropical montane evergreen forests, of the Nilgiri and Palni hills, Western Ghats, southern India. All woody lianas (≥1 cm dbh) were enumerated in plots of 30 × 30 m in small, medium and large forest patches, which were located along an altitudinal gradient ranging from 1700 to 2360 m. A total of 1980 individual lianas were recorded, belonging to 45 species, 32 genera and 21 families, from a total sampling area of 13.86 ha (across 154 plots). Liana species richness and density decreased significantly with increasing altitude and increased with increasing forest patch size. Within forest patches, the proportion of forest edge or interior habitat influenced liana distribution and succession especially when compared across the patch size categories. Liana species richness and density also varied along the altitudinal gradient when examined using eco-physiological guilds (i.e. shade tolerance, dispersal mode and climbing mechanism). The species richness and density of lianas within these ecological guilds responded negatively to increasing altitude and positively to increasing patch size and additionally displayed differing sensitivities to forest disturbance. Importantly, the degree of forest disturbance significantly altered the relationship between liana species richness and density to increasing altitude and patches size, and as such is likely the primary influence on liana response to montane forest succession. Our findings suggest that managing forest disturbance in the examined montane forests would assist in conserving local liana diversity across the examined altitudinal range.

      PubDate: 2017-06-22T01:20:11Z
      DOI: 10.1016/j.actao.2017.06.004
      Issue No: Vol. 83 (2017)
       
  • Ant-related oviposition is not associated to low parasitism of the
           myrmecophilous butterfly Allosmaitia strophius in an extrafloral nectaried
           shrub
    • Authors: Alexandra Bächtold; Estevão Alves-Silva; Kleber Del-Claro
      Pages: 15 - 21
      Abstract: Publication date: August 2017
      Source:Acta Oecologica, Volume 83
      Author(s): Alexandra Bächtold, Estevão Alves-Silva, Kleber Del-Claro
      In Lycaenidae-ant mutualisms, ovipositing females select plants based on the presence and/or species of ants in order to maximize survival rates of immatures. The ants are supposed to protect the immatures from parasitoids, but there is large variation in the protection provided. Here, we experimentally investigated whether the occurrence of the facultative myrmecophilous Allosmaitia strophius (the dominant species in our study system) was ant-related. The parasitism rates of immatures collected in the field and reared in the laboratory were also investigated. Stems of the extrafloral nectaried shrub Peixotoa tomentosa were designated as either ant-present (control) or absent (treated). The occurrence of A. strophius on ant-present stems was five times greater than on treated stems. Most eggs and larvae were associated with Camponotus blandus and Ectatomma tuberculatum, two aggressive ant species in the Brazilian savanna. Egg parasitism rate was 9%, and all the parasitized eggs were on ant-present stems. Pupal parasitism on ant-present and ant-absent stems was 25.6% and 7%, respectively. The higher parasitism rate in the presence of ants might also have been density-dependent, because caterpillars were more abundant in ant-present stems. Tropical lycaenids are frequently found in association with patrolling ants. Nevertheless, there is growing evidence that parasitism is higher in the presence of ants, owing to caterpillar's density-dependent effects in plants with ants, and/or to the weak lycaenid-ant associations. This indicates that the offspring of myrmecophilous lycaenids may not benefit, at least in terms of lower parasitism, by living with ants.

      PubDate: 2017-07-03T02:22:02Z
      DOI: 10.1016/j.actao.2017.06.007
      Issue No: Vol. 83 (2017)
       
  • How does vegetation structure influence woodpeckers and secondary cavity
           nesting birds in African cork oak forest'
    • Authors: Amalia Segura
      Pages: 22 - 28
      Abstract: Publication date: August 2017
      Source:Acta Oecologica, Volume 83
      Author(s): Amalia Segura
      The Great Spotted Woodpecker provides important information about the status of a forest in terms of structure and age. As a primary cavity creator, it provides small-medium size cavities for passerines. However, despite its interest as an ecosystem engineer, studies of this species in Africa are scarce. Here, spatially explicit predictive models were used to investigate how forest structural variables are related to both the Great Spotted Woodpecker and secondary cavity nesting birds in Maamora cork oak forest (northwest Morocco). A positive association between Great Spotted Woodpecker and both dead-tree density and large mature trees (>60 cm dbh) was found. This study area, Maamora, has an old-growth forest structure incorporating a broad range of size and condition of live and dead trees, favouring Great Spotted Woodpecker by providing high availability of foraging and excavating sites. Secondary cavity nesting birds, represented by Great Tit, African Blue Tit, and Hoopoe, were predicted by Great Spotted Woodpecker detections. The findings suggest that the conservation of the Maamora cork oak forest could be key to maintaining these hole-nesting birds. However, this forest is threatened by forestry practises and livestock overgrazing and the challenge is therefore to find sustainable management strategies that ensure conservation while allowing its exploitation.

      PubDate: 2017-07-03T02:22:02Z
      DOI: 10.1016/j.actao.2017.06.008
      Issue No: Vol. 83 (2017)
       
  • The effects of biome and spatial scale on the Co-occurrence patterns of a
           group of Namibian beetles
    • Authors: Monica Pitzalis; Francesca Montalto; Valentina Amore; Luca Luiselli; Marco A. Bologna
      Pages: 29 - 37
      Abstract: Publication date: August 2017
      Source:Acta Oecologica, Volume 83
      Author(s): Monica Pitzalis, Francesca Montalto, Valentina Amore, Luca Luiselli, Marco A. Bologna
      Co-occurrence patterns (studied by C-score, number of checkerboard units, number of species combinations, and V-ratio, and by an empirical Bayes approach developed by Gotelli and Ulrich, 2010) are crucial elements in order to understand assembly rules in ecological communities at both local and spatial scales. In order to explore general assembly rules and the effects of biome and spatial scale on such rules, here we studied a group of beetles (Coleoptera, Meloidae), using Namibia as a case of study. Data were gathered from 186 sampling sites, which allowed collection of 74 different species. We analyzed data at the level of (i) all sampled sites, (ii) all sites stratified by biome (Savannah, Succulent Karoo, Nama Karoo, Desert), and (iii) three randomly selected nested areas with three spatial scales each. Three competing algorithms were used for all analyses: (i) Fixed-Equiprobable, (ii) Fixed-Fixed, and (iii) Fixed-Proportional. In most of the null models we created, co-occurrence indicators revealed a non-random structure in meloid beetle assemblages at the global scale and at the scale of biomes, with species aggregation being much more important than species segregation in determining this non-randomness. At the level of biome, the same non-random organization was uncovered in assemblages from Savannah (where the aggregation pattern was particularly strong) and Succulent Karoo, but not in Desert and Nama Karoo. We conclude that species facilitation and similar niche in endemic species pairs may be particularly important as community drivers in our case of study. This pattern is also consistent with the evidence of a higher species diversity (normalized according to biome surface area) in the two former biomes. Historical patterns were perhaps also important for Succulent Karoo assemblages. Spatial scale had a reduced effect on patterning our data. This is consistent with the general homogeneity of environmental conditions over wide areas in Namibia.

      PubDate: 2017-07-03T02:22:02Z
      DOI: 10.1016/j.actao.2017.06.005
      Issue No: Vol. 83 (2017)
       
  • Effects of biotic and abiotic factors on the temporal dynamic of bat-fruit
           interactions
    • Authors: Rafael de Souza Laurindo; Renato Gregorin; Davi Castro Tavares
      Pages: 38 - 47
      Abstract: Publication date: August 2017
      Source:Acta Oecologica, Volume 83
      Author(s): Rafael de Souza Laurindo, Renato Gregorin, Davi Castro Tavares
      Mutualistic interactions between animals and plants vary over time and space based on the abundance of fruits or animals and seasonality. Little is known about this temporal dynamic and the influence of biotic and abiotic factors on the structure of interaction networks. We evaluated changes in the structure of network interactions between bats and fruits in relation to variations in rainfall. Our results suggest that fruit abundance is the main variable responsible for temporal changes in network attributes, such as network size, connectance, and number of interactions. In the same way, temperature positively affected the abundance of fruits and bats. An increase in temperature and alterations in rainfall patterns, due to human induced climate change, can cause changes in phenological patterns and fruit production, with negative consequences to biodiversity maintenance, ecological interactions, and ecosystem functioning.

      PubDate: 2017-07-03T02:22:02Z
      DOI: 10.1016/j.actao.2017.06.009
      Issue No: Vol. 83 (2017)
       
  • Edge, height and visibility effects on nest predation by birds and mammals
           in the Brazilian cerrado
    • Authors: Pavel Dodonov; Ingrid Toledo Paneczko; Marina Telles
      Pages: 56 - 64
      Abstract: Publication date: August 2017
      Source:Acta Oecologica, Volume 83
      Author(s): Pavel Dodonov, Ingrid Toledo Paneczko, Marina Telles
      Edge influence is one of the main impacts in fragmented landscapes; yet, most of studies on edge influence have focused on high-contrast edges, and the impacts of low-contrast edges and narrow linear openings are less understood. Edge influence often affects bird nest predation, but these effects are not ubiquitous and may depend on characteristics such as nest height and visibility. We performed an experiment on nest predation in a migratory passerine, Elaenia chiriquensis (Lesser Elaenia; Passeriformes: Tyrannidae), in a savanna vegetation of the Brazilian Cerrado biome in South-Eastern Brazil. We used 89 real E. chiriquensis nests, collected during previous reproductive seasons, with two plasticine eggs in each, and randomly distributed them at two locations (edge – up to 20 m from a firebreak edge and interior – approx. 150–350 m from the edge) and two heights (low – 60–175 cm and high – 190–315 cm above ground). We also measured leaf and branch density around each nest. We performed this study on two 15-days campaigns, checking the nests every 2–3 days and removing those with predation marks. We sorted the predation marks into those made by birds, mammals, or unidentified predators, and used generalized linear models to assess the effects of location, height and leaf density on survival time and predator type. Only four nests had not been predated during the experiment; 55 nests were predated by birds, 7 by mammals, and 23 by unidentified predators. Low nests in the interior tended to have larger survival times whereas high nests at the edge tended to be more predated by birds and less predated by mammals. Thus, even a low-contrast (firebreak) edge may significantly increase nest predation, which is also affected by the nest's height, mainly due to predation by birds. These effects may be due to predator movement along the edge as well as to edge-related changes in vegetation structure. We suggest that higher-contrast edges which may also be used as movement conduits, for example powerline openings, may have even stronger effects, demanding further studies.

      PubDate: 2017-07-12T01:34:51Z
      DOI: 10.1016/j.actao.2017.06.010
      Issue No: Vol. 83 (2017)
       
  • Fagus sylvatica L. provenances maintain different leaf metabolic profiles
           and functional response
    • Authors: Ismael Aranda; David Sánchez-Gómez; Marina de Miguel; Jose Antonio Mancha; María Angeles Guevara; Estrella Cadahía; María Brígida Fernández de Simón
      Pages: 1 - 9
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Ismael Aranda, David Sánchez-Gómez, Marina de Miguel, Jose Antonio Mancha, María Angeles Guevara, Estrella Cadahía, María Brígida Fernández de Simón
      Most temperate forest tree species will suffer important environmental changes as result of the climate change. Adaptiveness to local conditions could change at different sites in the future. In this context, the study of intra-specific variability is important to clarify the singularity of different local populations. Phenotypic differentiation between three beech provenances covering a wide latitudinal range (Spain/ES, Germany/DE and Sweden/SE), was studied in a greenhouse experiment. Non-target leaf metabolite profiles and ecophysiological response was analyzed in well-watered and water stressed seedlings. There was a provenance-specific pattern in the relative concentrations of some leaf metabolites regardless watering treatment. The DE and SE from the center and north of the distribution area of the species showed a clear differentiation from the ES provenance in the relative concentration of some metabolites. Thus the ES provenance from the south maintained larger relative concentration of some organic and amino acids (e.g. fumaric and succinic acids or valine and isoleucine), and in some secondary metabolites (e.g. kaempferol, caffeic and ferulic acids). The ecophysiological response to mild water stress was similar among the three provenances as a consequence of the moderate water stress applied to seedlings, although leaf N isotope composition (δ15N) and leaf C:N ratio were higher and lower respectively in DE than in the other two provenances. This would suggest potential differences in the capacity to uptake and post-process nitrogen according to provenance. An important focus of the study was to address for the first time inter-provenance leaf metabolic diversity in beech from a non-targeted metabolic profiling approach that allowed differentiation of the three studied provenances.

      PubDate: 2017-05-12T13:47:07Z
      DOI: 10.1016/j.actao.2017.05.003
      Issue No: Vol. 82 (2017)
       
  • The relationship between mammal faunas and climatic instability since the
           Last Glacial Maximum: A Nearctic vs. Western Palearctic comparison
    • Authors: Erik Joaquín Torres-Romero; Sara Varela; Jason T. Fisher; Miguel Á. Olalla-Tárraga
      Pages: 10 - 15
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Erik Joaquín Torres-Romero, Sara Varela, Jason T. Fisher, Miguel Á. Olalla-Tárraga
      Climate has played a key role in shaping the geographic patterns of biodiversity. The imprint of Quaternary climatic fluctuations is particularly evident on the geographic distribution of Holarctic faunas, which dramatically shifted their ranges following the alternation of glacial-interglacial cycles during the Pleistocene. Here, we evaluate the existence of differences between climatically stable and unstable regions – defined on the basis of climatic change velocity since the Last Glacial Maximum – in the geographic distribution of several biological attributes of extant terrestrial mammals of the Nearctic and Western Palearctic regions. Specifically, we use a macroecological approach to assess the dissimilarities in species richness, range size, body size, longevity and litter size of species that inhabit regions with contrasting histories of climatic stability. While several studies have documented how the distributional ranges of animals can be affected by long-term historic climatic fluctuations, there is less evidence on the species-specific traits that determine their responsiveness under such climatic instability. We find that climatically unstable areas have more widespread species and lower mammal richness than stable regions in both continents. We detected stronger signatures of historical climatic instability on the geographic distribution of body size in the Nearctic region, possibly reflecting lagged responses to recolonize deglaciated regions. However, the way that animals respond to climatic fluctuations varies widely among species and we were unable to find a relationship between climatic instability and other mammal life-history traits (longevity and litter size) in any of the two biogeographic regions. We, therefore, conclude that beyond some biological traits typical of macroecological analyses such as geographic range size and body size, it is difficult to infer the responsiveness of species distributions to climate change solely based on particular life-history traits.

      PubDate: 2017-05-22T14:25:20Z
      DOI: 10.1016/j.actao.2017.05.004
      Issue No: Vol. 82 (2017)
       
  • Calcareous forest seepages acting as biodiversity hotspots and refugia for
           woodland snail faunas
    • Authors: Michal Horsák; Eva Tajovská; Veronika Horsáková
      Pages: 16 - 22
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Michal Horsák, Eva Tajovská, Veronika Horsáková
      Land-snail species richness has repeatedly been found to increase with the increasing site calcium content and humidity. These two factors, reported as the main drivers of land-snail assemblage diversity, are also among the main habitat characteristics of calcareous seepages. Here we explore local species richness and compositional variation of forest spring-fed patches (i.e. seepages), to test the hypothesis that these habitats might act as biodiversity hotspots and refugia of regional snail faunas. In contrast to treeless spring fens, only little is known about land snail faunas inhabiting forest seepages. Studying 25 isolated calcareous forest seepages, evenly distributed across the White Carpathians Protected Landscape Area (SE Czech Republic), we found that these sites, albeit spatially very limited, can harbour up to 66% of the shelled land-snail species known to occur in this well-explored protected area (in total 83 species). By comparing land snail assemblages of the studied seepages with those occurring in the woodland surroundings of each site as well as those previously sampled in 28 preserved forest sites within the study area, we found the seepages to be among the most species rich sites. Although the numbers of species did not statistically differ among these three systems, we found highly significant differences in species composition. Seepage faunas were composed of many species significantly associated with spring sites, in contrast to the assemblages of both surrounding and preserved forest sites. Our results highly support the hypothesis that calcareous forest seepages might serve as refugia and biodiversity hotspots of regional land snail faunas. Protection of these unique habitats challenges both conservation plans and forest management guidelines as they might act as sources for the recolonization and restoration of forest snail assemblages particularly in areas impoverished by harvesting and clearcutting.

      PubDate: 2017-05-27T14:34:02Z
      DOI: 10.1016/j.actao.2017.05.006
      Issue No: Vol. 82 (2017)
       
  • Unravelling ecosystem functions at the Amazonia-Cerrado transition: II.
           Carbon stocks and CO2 soil efflux in cerradão forest undergoing
           ecological succession
    • Authors: Karine S. Peixoto; Ben Hur Marimon-Junior; Beatriz S. Marimon; Fernando Elias; Josenilton de Farias; Renata Freitag; Henrique A. Mews; Eder C. das Neves; Nayane Cristina C.S. Prestes; Yadvinder Malhi
      Pages: 23 - 31
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Karine S. Peixoto, Ben Hur Marimon-Junior, Beatriz S. Marimon, Fernando Elias, Josenilton de Farias, Renata Freitag, Henrique A. Mews, Eder C. das Neves, Nayane Cristina C.S. Prestes, Yadvinder Malhi
      The transition region between two major South American biomes, the Amazon forest and the Cerrado (Brazilian savanna), has been substantially converted into human-modified ecosystems. Nevertheless, the recovery dynamics of ecosystem functions in this important zone of (ecological) tension (ZOT) remain poorly understood. In this study, we compared two areas of cerradão (a forest-woodland of the Brazilian savanna; Portuguese augmentative of cerrado), one in secondary succession (SC) and one adjacent and well preserved (PC), to test whether the ecosystem functions lost after conversion to pasture were restored after 22 years of regeneration. We tested the hypothesis that the increase in annual aboveground biomass in the SC would be greater than that in the PC because of anticipated successional gains. We also investigated soil CO2 efflux, litter layer content, and fine root biomass in both the SC and PC. In terms of biomass recovery our hypothesis was not supported: the biomass did not increase in the successional area over the study period, which suggested limited capacity for recovery in this key ecosystem compartment. By contrast, the structure and function of the litter layer and root mat were largely reconstituted in the secondary vegetation. Overall, we provide evidence that 22 years of secondary succession were not sufficient for these short and open forests (e.g., cerradão) in the ZOT to recover ecosystem functions to the levels observed in preserved vegetation of identical physiognomy.

      PubDate: 2017-05-27T14:34:02Z
      DOI: 10.1016/j.actao.2017.05.005
      Issue No: Vol. 82 (2017)
       
  • Let native species take their course: Ambrosia artemisiifolia replacement
           during natural or “artificial” succession
    • Authors: Rodolfo Gentili; Chiara Montagnani; Federica Gilardelli; Maria Francesca Guarino; Sandra Citterio
      Pages: 32 - 40
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Rodolfo Gentili, Chiara Montagnani, Federica Gilardelli, Maria Francesca Guarino, Sandra Citterio
      Ambrosia artemisiifolia is able to dominate the early stages of vegetation succession in open/disturbed habitats, spreading out into available empty niches, after which it can be progressively replaced by perennial plants. In this study, we considered the time-span in which the species is suppressed during active (restoration actions) and passive (spontaneous) vegetation recovery. In particular, we envisaged that A. artemisiifolia growth and fitness may be strongly reduced and that the species may rapidly be suppressed within a short time during succession as a consequence of the increase of vegetation cover, both natural or artificially induced, in a disturbed area of northern Italy. Three different treatments were applied within an abandoned quarry area commonly invaded by A. artemisiifolia: (i) spontaneous succession i.e. (control), (ii) hayseed and (iii) a commercial seed mixture. We determined the effect of mixtures of grassland species, established from native hayseed or from a commercial seed mixture, on A. artemisiifolia growth and fitness traits over time in comparison to a non-seeded area left to spontaneous succession. The results demonstrated that, after the first growing season, compared with spontaneous succession, both commercial seed and hayseed resulted in a strong reduction of A. artemisiifolia abundance and growth rate, in terms of both vegetative and reproductive traits. After the second growing season, A. artemisiifolia was completely suppressed in the commercial seed treatment, and after the third growing season it was also suppressed in the spontaneous succession and hayseed treatments. This study indicated that both active and passive vegetation recovery (by niche filling and competitive exclusion) could be used as methods individually or in combination with other methods, such as mowing and biological control, to suppress A. artemisiifolia from anthropogenic habitats.

      PubDate: 2017-05-27T14:34:02Z
      DOI: 10.1016/j.actao.2017.05.007
      Issue No: Vol. 82 (2017)
       
  • Factors affecting seasonal habitat use, and predicted range of two
           tropical deer in Indonesian rainforest
    • Authors: Dede Aulia Rahman; Georges Gonzalez; Mohammad Haryono; Aom Muhtarom; Asep Yayus Firdaus; Stéphane Aulagnier
      Pages: 41 - 51
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Dede Aulia Rahman, Georges Gonzalez, Mohammad Haryono, Aom Muhtarom, Asep Yayus Firdaus, Stéphane Aulagnier
      There is an urgent recognized need for conservation of tropical forest deer. In order to identify some environmental factors affecting conservation, we analyzed the seasonal habitat use of two Indonesian deer species, Axis kuhlii in Bawean Island and Muntiacus muntjak in south-western Java Island, in response to several physical, climatic, biological, and anthropogenic variables. Camera trapping was performed in different habitat types during both wet and dry season to record these elusive species. The highest number of photographs was recorded in secondary forest and during the dry season for both Bawean deer and red muntjac. In models, anthropogenic and climatic variables were the main predictors of habitat use. Distances to cultivated area and to settlement were the most important for A. kuhlii in the dry season. Distances to cultivated area and annual rainfall were significant for M. muntjak in both seasons. Then we modelled their predictive range using Maximum entropy modelling (Maxent). We concluded that forest landscape is the fundamental scale for deer management, and that secondary forests are potentially important landscape elements for deer conservation. Important areas for conservation were identified accounting of habitat transformation in both study areas.

      PubDate: 2017-06-07T00:24:11Z
      DOI: 10.1016/j.actao.2017.05.008
      Issue No: Vol. 82 (2017)
       
  • Topographically-controlled site conditions drive vegetation pattern on
           inland dunes in Poland
    • Authors: Piotr Sewerniak; Michał Jankowski
      Pages: 52 - 60
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Piotr Sewerniak, Michał Jankowski
      The inland dunes of Central Europe are commonly overplanted by Scots pine (Pinus sylvestris) monocultures in which the primary occurrence of the natural vegetation pattern is obliterated. We hypothesize that on naturally revegetated inland dunes the pattern is clear and driven by topographically-controlled site conditions. To test this hypothesis, we addressed the following research questions: (1) Does topography drive vegetation patterns on inland dunes and if so, what are main differences between vegetation in varying relief positions' (2) To what extent does topography involve the variability of microclimates and of soil properties, and how does the topographically-induced differentiation of these site conditions control vegetation patterns' We conducted interdisciplinary studies (applying floristic, pedological and microclimatic research techniques) on a naturally revegetated inland dune area situated on a military artillery training ground near Toruń, northern Poland. We investigated vegetation patterns with reference to three topographical position variants (north-facing slopes, south-facing slopes, and intra-dune depressions). We found distinct differences in vegetation characteristics covering the aforementioned topographical positions. This primarily concerned species composition of ground vegetation: Calluna vulgaris was dominant species on north-facing slopes, Corynephorus canescens on south-facing slopes, while Calamagrostis epigejos in intra-dune depressions. In comparison to dune slopes, the depressions were characterized by much higher biodiversity of vascular plant species. This followed the most favorable soil conditions for the existence of plants (higher moisture and nutrient pools) occurring in low topographical positions. However, tree succession was most advanced not in depressions, where the competitive impact of tall grasses on seedlings was recognized, but on north-facing slopes. Based on our results, we formulated some suggestions, which could be useful for both practical foresters to increase biodiversity of ecosystems and for practices that work on the fixation of dunes by restoring vegetation.

      PubDate: 2017-06-17T01:00:32Z
      DOI: 10.1016/j.actao.2017.06.003
      Issue No: Vol. 82 (2017)
       
  • Effects of temporally biased watering on the nitrogen response of
           Chenopodium album
    • Authors: Toshihiko Kinugasa; Yumi Hozumi
      Pages: 61 - 68
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Toshihiko Kinugasa, Yumi Hozumi
      Plant growth responses to an increasing N deposition are stimulated by an increase in annual precipitation, but such a stimulation has not always been found. We hypothesized that the effect of precipitation on plant N responses can change with temporally biased precipitation: a plant N response will be suppressed when precipitation is lower in the late growing period because larger plants are more susceptible to water limitations. We grew Chenopodium album under a high and low N application level with three watering patterns while maintaining the total supplied watering amount during the experimental period: constant watering, low watering in the first period and high watering in the latter period, and high watering in the first period and low watering in the latter period. The watering pattern did not affect plant dry mass under low N conditions. The plant dry mass under high N conditions was reduced by low watering in the first period, but the reduction was fully compensated in the subsequent high watering period by the stimulation of photosynthesis. Low watering following high watering under high N conditions did not suppress plant growth, but partial leaf wilting was observed at the end of the experimental period. Finally, at the end of the experiment, the response of plant dry mass to N was not different among the watering patterns. We concluded that a plant's response to increasing N deposition could be affected by temporally biased precipitation, depending on the scale of the precipitation bias and the ability of the plant to compensate or mitigate growth inhibition due to a water deficit. Precipitation deficits later in the growing period may be more detrimental to plant growth and can reduce plant responses to an increasing N deposition.

      PubDate: 2017-06-17T01:00:32Z
      DOI: 10.1016/j.actao.2017.06.001
      Issue No: Vol. 82 (2017)
       
  • The effect of spatial context and plant characteristics on fruit removal
    • Authors: Florencia Tiribelli; Guillermo Cesar Amico; Yamila Sasal; Juan Manuel Morales
      Pages: 69 - 74
      Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82
      Author(s): Florencia Tiribelli, Guillermo Cesar Amico, Yamila Sasal, Juan Manuel Morales
      Attracting frugivores for fruit removal is a crucial step in the reproductive success of those plants that depend on animals for seed dispersal. This mutualism involves many plant extrinsic and intrinsic factors that affect fruit removal. Along the northern portion of the temperate forest of southern South America, the nocturnal marsupial Dromiciops gliroides is the only effective disperser of the mistletoe Tristerix corymbosus. This system, where a single disperser removes the fruits of a plant is simple compared to systems that include multiple dispersers and represents a unique opportunity to study the effect of extrinsic and intrinsic factors in frugivore plant choices for fruit removal. With a hierarchical model, we evaluated the effects of spatial context (accessibility and tree cover) and plant characteristics (age and crop size) in fruit removal during four fruiting seasons. While all these variables affected fruit removal, only accessibility and plant age had consistent and positive effects across years. After studying four fruiting seasons, we found that characteristics associated with frugivores’ habits are the most important factors for the reproductive success of plants dispersed by animals.

      PubDate: 2017-06-17T01:00:32Z
      DOI: 10.1016/j.actao.2017.06.002
      Issue No: Vol. 82 (2017)
       
  • Do forest soil microbes have the potential to resist plant invasion? A
           case study in Dinghushan Biosphere Reserve (South China)
    • Authors: Bao-Ming Chen; Song Li; Hui-Xuan Liao; Shao-Lin Peng
      Pages: 1 - 9
      Abstract: Publication date: May 2017
      Source:Acta Oecologica, Volume 81
      Author(s): Bao-Ming Chen, Song Li, Hui-Xuan Liao, Shao-Lin Peng
      Successful invaders must overcome biotic resistance, which is defined as the reduction in invasion success caused by the resident community. Soil microbes are an important source of community resistance to plant invasions, and understanding their role in this process requires urgent investigation. Therefore, three forest communities along successional stages and four exotic invasive plant species were selected to test the role of soil microbes of three forest communities in resisting the exotic invasive plant. Our results showed that soil microbes from a monsoon evergreen broadleaf forest (MEBF) (late-successional stage) had the greatest resistance to the invasive plants. Only the invasive species Ipomoea triloba was not sensitive to the three successional forest soils. Mycorrhizal fungi in early successional forest Pinus massonina forest (PMF) or mid-successional forest pine-broadleaf mixed forest (PBMF) soil promoted the growth of Mikania micrantha and Eupatorium catarium, but mycorrhizal fungi in MEBF soil had no significant effects on their growth. Pathogens plus other non-mycorrhizal microbes in MEBF soil inhibited the growth of M. micrantha and E. catarium significantly, and only inhibited root growth of E. catarium when compared with those with mycorrhizal fungi addition. The study suggest that soil mycorrhizal fungi of early-mid-successional forests benefit invasive species M. micrantha and E. catarium, while soil pathogens of late-successional forest may play an important role in resisting M. micrantha and E. catarium. The benefit and resistance of the soil microbes are dependent on invasive species and related to forest succession. The study gives a possible clue to control invasive plants by regulating soil microbes of forest community to resist plant invasion.

      PubDate: 2017-04-26T13:09:14Z
      DOI: 10.1016/j.actao.2017.04.003
      Issue No: Vol. 81 (2017)
       
  • Taxa-specific eco-sensitivity in relation to phytoplankton bloom stability
           and ecologically relevant lake state
    • Authors: Agnieszka Napiórkowska-Krzebietke; Julita A. Dunalska; Elżbieta Zębek
      Pages: 10 - 21
      Abstract: Publication date: May 2017
      Source:Acta Oecologica, Volume 81
      Author(s): Agnieszka Napiórkowska-Krzebietke, Julita A. Dunalska, Elżbieta Zębek
      Phytoplankton (including plant-like, animal-like algae and Cyanobacteria) blooms have recently become a serious global threat to the sustenance of ecosystems, to human and animal health and to economy. This study focused on the composition and stability of blooms as well as their taxa-specific ecological sensitivity to the main causal factors (especially phosphorus and nitrogen) in degraded urban lakes. The analyzed lakes were assessed with respect to the trophic state as well as ecological status. Total phytoplankton biomass (ranging from 1.5 to 181.3 mg dm−3) was typical of blooms of different intensity, which can appear during a whole growing season but are the most severe in early or late summer. Our results suggested that steady-state and non-steady-state bloom assemblages including mono-, bi- and multi-species or heterogeneous blooms may occur in urban lakes. The most intense blooms were formed by the genera of Cyanobacteria: Microcystis, Limnothrix, Pseudanabaena, Planktothrix, Bacillariophyta: Cyclotella and Dinophyta mainly Ceratium and Peridinium. Considering the sensitivity of phytoplankton assemblages, a new eco-sensitivity factor was proposed (E-SF), based on the concept of Phytoplankton Trophic Index composed of trophic scores of phytoplankton taxa along the eutrophication gradient. The E-SF values of 0.5, 1.3, 6.7 and 15.1 were recognized in lakes having a high, good, moderate or poor ecological status, respectively. For lake restoration, each type of bloom should be considered separately because of different sensitivities of taxa and relationships with environmental variables. Proper recognition of the taxa-specific response to abiotic (especially to N and P enrichment) and biotic factors could have significant implications for further water protection and management.

      PubDate: 2017-04-26T13:09:14Z
      DOI: 10.1016/j.actao.2017.04.002
      Issue No: Vol. 81 (2017)
       
  • Clipping and irrigation enhance grass biomass and nutrients: Implications
           for rangeland management
    • Authors: Samuel Tuffa; Dana Hoag; Anna C. Treydte
      Pages: 32 - 39
      Abstract: Publication date: May 2017
      Source:Acta Oecologica, Volume 81
      Author(s): Samuel Tuffa, Dana Hoag, Anna C. Treydte
      Increasing frequency of drought and high herbivore pressure significantly affect individual grass functions in semiarid regions. Reseeding of degraded rangelands by native grass species has been recommended as a tool for restoration semiarid rangelands. However, how grass species used for reseeding respond to stressors has not been fully explored. We examined biomass allocation and nutrient contents of Cenchrus ciliaris and Chloris gayana in the semiarid Borana rangelands, Ethiopia. We tested clipped mature tufts of the same species for biomass allocation and nutritive values. Further, shifts in rainfall and herbivory were simulated by three irrigation and four clipping treatments, respectively, for newly established grasses in pot and field plot experiments. Aboveground biomass (AGB) significantly declined by up to 75% under increased clipping in mature tufts. In contrast, clipping significantly stimulated up to 152% higher AGB of newly established grasses. Lower irrigation reduced the AGB by 24 and 42% in C. ciliaris and in C. gayana, respectively. Clipping, further, significantly enhanced grass nutrients in grass tufts by up to 82 and 105% in C. ciliaris and C. gayana, respectively. Hence, management should focus on balancing this trade-off in mature grasses for nutritious rangeland production by clipping and storing for later supplemental feeding when grass nutrients drop. Further, young pastures should be moderately clipped/grazed for better establishment and biomass allocation. Additionally, our experiments established the first interactive effect of clipping and irrigation frequencies on the biomass allocation of native grasses in the semiarid Borana rangelands, Ethiopia. Knowledge of these interacting factors is deemed essential for policy makers to enhance productivity of degraded rangelands such as the Borana rangelands.

      PubDate: 2017-05-08T13:40:11Z
      DOI: 10.1016/j.actao.2017.05.001
      Issue No: Vol. 81 (2017)
       
  • Latitudinal variation of life-history traits of an exotic and a native
           impatiens species in Europe
    • Authors: Kamal Prasad Acharya; Pieter De Frenne; Jörg Brunet; Olivier Chabrerie; Sara A.O. Cousins; Martin Diekmann; Martin Hermy; Annette Kolb; Isgard Lemke; Jan Plue; Kris Verheyen; Bente Jessen Graae
      Pages: 40 - 47
      Abstract: Publication date: May 2017
      Source:Acta Oecologica, Volume 81
      Author(s): Kamal Prasad Acharya, Pieter De Frenne, Jörg Brunet, Olivier Chabrerie, Sara A.O. Cousins, Martin Diekmann, Martin Hermy, Annette Kolb, Isgard Lemke, Jan Plue, Kris Verheyen, Bente Jessen Graae
      Understanding the responses of invasive and native populations to environmental change is crucial for reliable predictions of invasions in the face of global change. While comparisons of responses across invasive species with different life histories have been performed before, comparing functional traits of congeneric native and invasive species may help to reveal driving factors associated with invasion. Here we compared morphological functional trait patterns of an invasive species (Impatiens parviflora) with its congeneric native species (I. noli-tangere) along an approximately 1600 km European latitudinal gradient from France (49°34′N) to Norway (63°40′N). Soil nitrogen was recorded during six weeks of the growing season, and light, soil moisture, and nutrient availability were estimated for each sampled population using community weighted means of indicator values for co-occurring species. Temperature data were gathered from nearby weather stations. Both the native and invasive species are taller at higher latitudes and this response is strongest in the invasive species. Seed mass and number of seeds per capsule increase in I. noli-tangere but decrease in I. parviflora towards higher latitudes. Surprisingly, plant height in the invasive I. parviflora decreases with increasing soil nitrogen availability. The latitudinal pattern in seed mass is positively related to temperature in I. noli-tangere and negatively in I. parviflora. Leaf area of both species decreases with increasing Ellenberg indicator values for nitrogen and light but increases with increasing soil moisture. Soil nitrogen concentrations and Ellenberg indicator values for nitrogen have significant positive (I. noli-tangere) and negative (I. parviflora) effects on the number of seeds per capsule. Our results show that the native I. noli-tangere has efficient reproduction at its range edge while the invasive I. parviflora shows a marked decrease in seed size and seed number per capsule. These patterns are unrelated to the growth and obtained size of the plants: even low soil nitrogen availability in the north seemed not to limit plant growth and size. Our results suggest that the invasive I. parviflora tends to become more invasive at lower latitudes by producing heavier seeds and more seeds per capsule.

      PubDate: 2017-05-12T13:47:07Z
      DOI: 10.1016/j.actao.2017.05.002
      Issue No: Vol. 81 (2017)
       
  • Is the ecological belt zonation of the Swiss Alps relevant for moth
           diversity and turnover?
    • Authors: Jan Beck; Cecil M. Rüdlinger; Christy M. McCain
      Pages: 1 - 7
      Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80
      Author(s): Jan Beck, Cecil M. Rüdlinger, Christy M. McCain
      Mountain ecosystems are traditionally envisioned as elevational belts of homogenous vegetation, separated by intervening ecotones. Recent research has cast doubt on such predictable layering at least in animal communities. We test the link of two a priori defined ecological belt zonations to noctuid moth distributions in the Swiss Alps. Predictions, in particular, were a coincidence of proposed ecotones with increased range endpoint frequencies and with increased species turnover or species richness between equidistant elevational bands. Using >320,000 distributional records for >500 noctuid species, we found no support for these three predictions despite several contrasting analytical approaches. Concurrent with recently published vertebrate data, we conclude that simple ecological belt zonations are unrelated to the moth communities found along mountain slopes. Rather, species are distributed idiosyncratically following their specific niche requirements. Additional rigorous evidence, particularly comparing insect clades spanning a spectrum of host-plant relationships, may be required to support the relevance of the ecological belt concept in structuring mountain ecosystems beyond tree and plant communities.

      PubDate: 2017-02-25T08:38:00Z
      DOI: 10.1016/j.actao.2017.02.001
      Issue No: Vol. 80 (2017)
       
  • A predictive relationship between population and genetic sex ratios in
           clonal species
    • Authors: D. Nicholas McLetchie; Gisela García-Ramos
      Pages: 18 - 23
      Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80
      Author(s): D. Nicholas McLetchie, Gisela García-Ramos
      Sexual reproduction depends on mate availability that is reflected by local sex ratios. In species where both sexes can clonally expand, the population sex ratio describes the proportion of males, including clonally derived individuals (ramets) in addition to sexually produced individuals (genets). In contrast to population sex ratio that accounts for the overall abundance of the sexes, the genetic sex ratio reflects the relative abundance of genetically unique mates, which is critical in predicting effective population size but is difficult to estimate in the field. While an intuitive positive relationship between population (ramet) sex ratio and genetic (genet) sex ratio is expected, an explicit relationship is unknown. In this study, we determined a mathematical expression in the form of a hyperbola that encompasses a linear to a nonlinear positive relationship between ramet and genet sex ratios. As expected when both sexes clonally have equal number of ramets per genet both sex ratios are identical, and thus ramet sex ratio becomes a linear function of genet sex ratio. Conversely, if sex differences in ramet number occur, this mathematical relationship becomes nonlinear and a discrepancy between the sex ratios amplifies from extreme sex ratios values towards intermediate values. We evaluated our predictions with empirical data that simultaneously quantified ramet and genet sex ratios in populations of several species. We found that the data support the predicted positive nonlinear relationship, indicating sex differences in ramet number across populations. However, some data may also fit the null model, which suggests that sex differences in ramet number were not extensive, or the number of populations was too small to capture the curvature of the nonlinear relationship. Data with lack of fit suggest the presence of factors capable of weakening the positive relationship between the sex ratios. Advantages of this model include predicting genet sex ratio using population sex ratios given known sex differences in ramet number, and detecting sex differences in ramet number among populations.

      PubDate: 2017-03-09T15:38:54Z
      DOI: 10.1016/j.actao.2017.02.002
      Issue No: Vol. 80 (2017)
       
  • Contrasting patterns of fine-scale herb layer species composition in
           temperate forests
    • Authors: Markéta Chudomelová; David Zelený; Ching-Feng Li
      Pages: 24 - 31
      Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80
      Author(s): Markéta Chudomelová, David Zelený, Ching-Feng Li
      Although being well described at the landscape level, patterns in species composition of forest herb layer are rarely studied at smaller scales. Here, we examined fine-scale environmental determinants and spatial structures of herb layer communities in thermophilous oak- and hornbeam dominated forests of the south-eastern part of the Czech Republic. Species composition of herb layer vegetation and environmental variables were recorded within a fixed grid of 2 × 2 m subplots regularly distributed within 1-ha quadrate plots in three forest stands. For each site, environmental models best explaining species composition were constructed using constrained ordination analysis. Spatial eigenvector mapping was used to model and account for spatial structures in community variation. Mean Ellenberg indicator values calculated for each subplot were used for ecological interpretation of spatially structured residual variation. The amount of variation explained by environmental and spatial models as well as the selection of variables with the best explanatory power differed among sites. As an important environmental factor, relative elevation was common to all three sites, while pH and canopy openness were shared by two sites. Both environmental and community variation was mostly coarse-scaled, as was the spatially structured portion of residual variation. When corrected for bias due to spatial autocorrelation, those environmental factors with already weak explanatory power lost their significance. Only a weak evidence of possibly omitted environmental predictor was found for autocorrelated residuals of site models using mean Ellenberg indicator values. Community structure was determined by different factors at different sites. The relative importance of environmental filtering vs. spatial processes was also site specific, implying that results of fine-scale studies tend to be shaped by local conditions. Contrary to expectations based on other studies, overall dominance of spatial processes at fine scale has not been detected. Ecologists should keep this in mind when making generalizations about community dynamics.

      PubDate: 2017-03-17T10:27:26Z
      DOI: 10.1016/j.actao.2017.02.003
      Issue No: Vol. 80 (2017)
       
  • Root responses to nitrogen pulse frequency under different nitrogen
           amounts
    • Authors: Qing-Ye Yuan; Pu Wang; Lu Liu; Bi-Cheng Dong; Fei-Hai Yu
      Pages: 32 - 38
      Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80
      Author(s): Qing-Ye Yuan, Pu Wang, Lu Liu, Bi-Cheng Dong, Fei-Hai Yu
      Responses of morphology and biomass allocation of roots to frequency of nitrogen (N) pulse potentially influence the fitness of plants, but such responses may be determined by root size. We grew 12 plant species of three functional groups (grasses, forbs, and legumes) under two N pulse frequencies (high vs. low supply frequency) and two N amounts (high vs. low supply amount). Compared to low-amount N supply, high-amount N supply stimulated biomass accumulation and root growth by either increasing the thickness and length of roots or decreasing the root mass fraction. Compared to low-frequency N supply, high-frequency N supply improved biomass accumulation and root growth in forbs or grasses, but not in legumes. Furthermore, the magnitude of the response to N frequency was significantly negatively correlated with root size at the species scale, but this was only true when the N amount was high. We conclude that root responses to N frequency are related to plant functional types, and non-legume species is more sensitive to N frequency than legume species. Our results also suggest that root size is a determinant of root responses to N frequency when N supply amount is high.

      PubDate: 2017-03-21T20:48:33Z
      DOI: 10.1016/j.actao.2017.03.001
      Issue No: Vol. 80 (2017)
       
  • Differential endozoochory of aquatic invertebrates by two duck species in
           shallow lakes
    • Authors: Luis Valls; Andreu Castillo-Escrivà; Luis Barrera; Eulalia Gómez; José Antonio Gil-Delgado; Francesc Mesquita-Joanes; Xavier Armengol
      Pages: 39 - 46
      Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80
      Author(s): Luis Valls, Andreu Castillo-Escrivà, Luis Barrera, Eulalia Gómez, José Antonio Gil-Delgado, Francesc Mesquita-Joanes, Xavier Armengol
      Animal vectors are essential for the movement of invertebrate resting eggs between water bodies. However, differences in habitat preferences and feeding behaviour between bird species may result in variations in the dispersal of invertebrates via these birds, even if the different bird species live in the same lake. To test such effects, faecal samples from Anas platyrhynchos (collected in autumn and spring) and Tadorna tadorna (collected in spring) were cultured in water at 20° C and 12 L: 12 D conditions in order to quantify the resting eggs which could be internally transported by these birds. One half of each faecal sample was initially cultured at a conductivity of 0.6 mS cm−1 and the other half at 6 mS cm−1. 1054 invertebrates hatched from a total of 60 faecal samples, including cladocerans, copepods, ostracods, rotifers and ciliates, with a wide variability among faeces. Autumn yielded a low proportion of samples with hatchlings (12.5%) compared to spring (90%). Significant differences were observed between birds, but not between conductivity treatments. Thus, our results imply different hatching dynamics affected by disperser and season, but most species transported as resting eggs by birds seem to have a wide tolerance to hatch under variable salinity conditions. These differences may largery influence the metacommunity dynamics of lake networks, and could be a key factor to consider in wetland conservation planning.

      PubDate: 2017-03-28T21:09:42Z
      DOI: 10.1016/j.actao.2017.03.003
      Issue No: Vol. 80 (2017)
       
  • Temporal changes in native-exotic richness correlations during early
           post-fire succession
    • Authors: Qinfeng Guo
      Pages: 47 - 50
      Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80
      Author(s): Qinfeng Guo
      The relationship between native and exotic richness has mostly been studied with respect to space (i.e., positive at larger scales, but negative or more variable at smaller scales) and its temporal patterns have rarely been investigated. Although some studies have monitored the temporal trends of both native and exotic richness, how these two groups of species might be related to each other and how their relative proportions vary through time in a local community remains unclear. Re-analysis of early post-fire successional data for a California chaparral community shows that, in the same communities and at small spatial scales, the native-exotic correlations varied through time. Both exotic richness and exotic fraction (i.e., the proportion of exotic species in the flora) quickly increased and then gradually declined, during the initial stages of succession following fire disturbance. This result sheds new light on habitat invasibility and has implications for timing the implementation of effective management actions to prevent and/or mitigate species invasions.

      PubDate: 2017-03-28T21:09:42Z
      DOI: 10.1016/j.actao.2017.03.002
      Issue No: Vol. 80 (2017)
       
  • Local adaptation in oviposition choice of a specialist herbivore: The
           cinnabar moth
    • Authors: Xianqin Wei; Klaas Vrieling; Patrick P.J. Mulder; Peter G.L. Klinkhamer
      Pages: 1 - 7
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Xianqin Wei, Klaas Vrieling, Patrick P.J. Mulder, Peter G.L. Klinkhamer
      Specialist herbivores feed on a restricted number of related plant species and may suffer food shortage if overexploitation leads to periodic defoliation of their food plants. The density, size and quality of food plants are important factors that determine the host plant choice of specialist herbivores. To explore how all these factors influence their oviposition behaviour, we used the cinnabar moth Tyria jacobaeae and the hybrids of a cross between Jacobaea vulgaris and J. aquatica as a study system. While defoliation by the cinnabar moth is common in the coastal area of The Netherlands, it is relatively rare in inland ragwort population. Ragworts contain pyrrolizidine alkaloids (PAs) and those that are found in coastal areas are rich in jacobine-like PAs while those that occur inland are rich in erucifoline-like PAs. We tested how the oviposition preference was influenced by plant size, nitrogen and water content and PA composition. We used cinnabar moth populations from a regularly defoliated area, Meijendel, and Bertogne, a rarely defoliated area. Our results revealed no effects of nitrogen or water content on oviposition preference. Moths from both populations laid larger egg batches on the plants rich in jacobine-like PAs. Moths from Meijendel preferred larger plants and spread their eggs over more egg batches that were, on average, smaller than those of Bertogne moths. These results suggest that Meijendel moths adopted a oviposition strategy to cope with potential defoliation.

      PubDate: 2017-01-15T18:02:35Z
      DOI: 10.1016/j.actao.2017.01.001
      Issue No: Vol. 79 (2017)
       
  • Changes in arbuscular mycorrhizal fungal communities along a river delta
           island in northeastern Brazil
    • Authors: Iolanda Ramalho da Silva; Danielle Karla Alves da Silva; Francisco Adriano de Souza; Fritz Oehl; Leonor Costa Maia
      Pages: 8 - 17
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Iolanda Ramalho da Silva, Danielle Karla Alves da Silva, Francisco Adriano de Souza, Fritz Oehl, Leonor Costa Maia
      Arbuscular mycorrhizal fungi (AMF) play a key role in the maintenance of the balance of terrestrial ecosystems, but little is known about the biogeography of these fungi, especially on tropical islands. This study aims to compare AMF community structure along a transect crossing a fluvial-marine island and relate these communities with soil and vegetation parameters to shed light on the forces driving AMF community structure on a local scale. We tested the hypothesis that the composition of AMF communities changes across the island, even within short distances among sites, in response to differences in edaphic characteristics and vegetation physiognomies. We sampled roots and soils in five different natural and degraded habitats: preserved mangrove forest (MF), degraded mangrove forest (MD), natural Restinga forest (RF), and two regeneration Restinga forests (RR1 and RR2) on Ilha da Restinga, northeastern Brazil. We determined the mycorrhizal colonization rate and AMF community structure based on morphological spore identification. The island soils were sandy with pH varying from acid to neutral; higher levels of organic matter were registered in RF and lower in MF; other chemical and physical soil attributes differed along the habitat types on the island. In total, 22 AMF species were identified, without any difference in species richness. However, the diversity and composition of AMF communities, spore abundance per families, and mycorrhizal colonization were statistically different among the habitats. The composition of AMF communities was strongly related to soil characteristics, especially the sum of exchangeable bases. Our results indicate that the different habitat types have diverse AMF communities even within short distances among habitats. In conclusion, islands with high spatial heterogeneity in soil parameters and diverse vegetation are potential refuges for the diversity conservation of AM fungi.

      PubDate: 2017-01-22T18:21:51Z
      DOI: 10.1016/j.actao.2016.12.011
      Issue No: Vol. 79 (2017)
       
  • Settlements as a source for the spread of non-native plants into Central
           European suburban forests
    • Authors: Luca Gaggini; Hans-Peter Rusterholz; Bruno Baur
      Pages: 18 - 25
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Luca Gaggini, Hans-Peter Rusterholz, Bruno Baur
      Urbanization is considered as a major driver for biotic homogenization. Urbanization also promotes the dispersal of non-native species. This study examined the roles of suburban settlements and of the surrounding landscape composition for the spread of non-native plant species into adjacent mixed deciduous forests in Southern and Northwestern Switzerland. The number and abundance of native and non-native vascular plant species in both the ground vegetation and shrub layer were recorded in 15 forest sites situated adjacent to settlements and 15 control sites far from settlements. Various site and landscape characteristics were assessed in the surroundings (100 m radius) of the study sites. In both regions we found a higher number and larger abundance of non-native plant species in forest sites adjacent to settlements than in control forest sites. Furthermore, non-native plants were more frequently recorded close to roads and in sites surrounded by a large percentage cover of garden. All these effects were more pronounced in Southern Switzerland, a region with milder winter climate, than in Northwestern Switzerland. Our study showed that settlements are a source for the spread of non-native plant species into Central European suburban forests, and that the composition of the surrounding landscape matrix (e.g. traffic infrastructure, percentage cover of gardens) also affects the establishment of non-native plants.

      PubDate: 2017-01-22T18:21:51Z
      DOI: 10.1016/j.actao.2016.12.008
      Issue No: Vol. 79 (2017)
       
  • Sexual segregation in foraging giraffe
    • Authors: Rosemary Peter Mramba; Obeid Mahenya; Annetjie Siyaya; Karen Marie Mathisen; Harry Peter Andreassen; Christina Skarpe
      Pages: 26 - 35
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Rosemary Peter Mramba, Obeid Mahenya, Annetjie Siyaya, Karen Marie Mathisen, Harry Peter Andreassen, Christina Skarpe
      Sexual segregation in giraffe is known to vary between savannas. In this study, we compared sexual segregation in giraffe in one nutrient-rich savanna, the Serengeti National Park, one nutrient-poor, Mikumi National Park, and one medium rich savanna, Arusha National Park, (from here on referred to just by name) based on effects of sexual size dimorphism and related hypotheses. Data were collected in the wet and dry seasons, by driving road transects and making visual observations of browsing giraffe. Additional data were collected from literature (plant chemistry; mammal communities). There was a noticeable difference in browsing by females and males and in browsing between the three savannas. Females browsed a higher diversity of tree species in Serengeti whereas males browsed a higher diversity in Arusha, while the diversity of species browsed in Mikumi was high and about the same in both sexes. Females selected for high concentrations of nitrogen and low concentrations of tannins and phenolics compared to males in Serengeti but selection in Mikumi was more complex. Males browsed higher in the canopy than females in all sites, but the browsing height was generally higher in Serengeti than Mikumi and Arusha. Season had an effect on the browsing height independent of sex in Mikumi, where giraffes browsed higher in the dry season compared to the wet season. Males spent more time browsing per tree compared to females in all three sites; however, browsing time in Mikumi was also affected by season, where giraffes had longer browsing bouts in the wet season compared to the dry season. We suggest that sexual differences in forage requirement and in foraging interacts with differences in tree chemistry and in competing herbivore communities between nutrient rich and nutrient poor savanna in shaping the sexual segregation.

      PubDate: 2017-01-15T18:02:35Z
      DOI: 10.1016/j.actao.2016.12.007
      Issue No: Vol. 79 (2017)
       
  • Nuclear DNA contents of Echinchloa crus-galli and its Gaussian
           relationships with environments
    • Authors: Dan-Dan Li; Yong-Liang Lu; Shui-Liang Guo; Li-Ping Yin; Ping Zhou; Yu-Xia Lou
      Pages: 36 - 47
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Dan-Dan Li, Yong-Liang Lu, Shui-Liang Guo, Li-Ping Yin, Ping Zhou, Yu-Xia Lou
      Previous studies on plant nuclear DNA content variation and its relationships with environmental gradients produced conflicting results. We speculated that the relationships between nuclear DNA content of a widely-distributed species and its environmental gradients might be non-linear if it was sampled in a large geographical gradient. Echinochloa crus-galli (L.) P. Beauv. is a worldwide species, but without documents on its intraspecific variation of nuclear DNA content. Our objectives are: 1) to detect intraspecific variation scope of E. crus-galli in its nuclear DNA content, and 2) to testify whether nuclear DNA content of the species changes with environmental gradients following Gaussian models if its populations were sampled in a large geographical gradient. We collected seeds of 36 Chinese populations of E. crus-galli across a wide geographical gradient, and sowed them in a homogeneous field to get their offspring to determine their nuclear DNA content. We analyzed the relationships of nuclear DNA content of these populations with latitude, longitude, and nineteen bioclimatic variables by using Gaussian and linear models. (1) Nuclear DNA content varied from 2.113 to 2.410 pg among 36 Chinese populations of E. crus-galli, with a mean value of 2.256 pg. (2) Gaussian correlations of nuclear DNA content (y) with geographical gradients were detected, with latitude (x) following y = 2.2923 *e − ( x − 24.9360 ) 2 2 * 63.7945 2 (r = 0.546, P < 0.001), and with longitude (x) following y = 2.2933 *e − ( x − 116.1801 ) 2 2 * 44.7450 2 (r = 0.672, P < 0.001). (3) Among the nineteen bioclimatic variables, except temperature isothermality, precipitations of the wettest month, the wettest quarter and the warmest quarter, the others could be better fit with nuclear DNA content by using Gaussian models than by linear models. There exists intra-specific variation among 36 Chinese populations of E. crus-galli, Gaussian models could be applied to fit the correlations of its Nuclear DNA content with geographical and most bioclimatic gradients.

      PubDate: 2017-01-22T18:21:51Z
      DOI: 10.1016/j.actao.2017.01.002
      Issue No: Vol. 79 (2017)
       
  • Arbuscular mycorrhizal fungal community composition associated with
           Juniperus brevifolia in native Azorean forest
    • Authors: Catarina Drumonde Melo; Sara Luna; Claudia Krüger; Christopher Walker; Duarte Mendonça; Henrique M.A.C. Fonseca; Maria Jaizme-Vega; Artur da Câmara Machado
      Pages: 48 - 61
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Catarina Drumonde Melo, Sara Luna, Claudia Krüger, Christopher Walker, Duarte Mendonça, Henrique M.A.C. Fonseca, Maria Jaizme-Vega, Artur da Câmara Machado
      The communities of glomeromycotan fungi (arbuscular mycorrhizal fungi, AMF) under native Juniperus brevifolia forest from two Azorean islands, Terceira and São Miguel, were compared, mainly by spore morphology, and when possible, by molecular analysis. Thirty-nine morphotypes were detected from 12 genera. Glomeromycotan fungal richness was similar in Terceira and São Miguel, but significantly different among the four fragments of native forest. Spore diversity and community composition differed significantly between the two islands. The less degraded island, Terceira, showed 10 exclusive morphotypes including more rare types, whereas the more disturbed forest on São Miguel showed 13 morphs, mostly of common types. Forests from Terceira were dominated by Acaulosporaceae and Glomeraceae. Whereas members of Acaulosporaceae, Glomeraceae and Ambisporaceae were most frequent and abundant in those from São Miguel. Spore abundance was greatest on Terceira, and correlated with soil chemical properties (pH), average monthly temperature and relative humidity.

      PubDate: 2017-01-22T18:21:51Z
      DOI: 10.1016/j.actao.2016.12.006
      Issue No: Vol. 79 (2017)
       
  • A minimum stochastic model evaluating the interplay between population
           density and drift for species coexistence
    • Authors: Rafael Dettogni Guariento; Adriano Caliman
      Pages: 62 - 69
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Rafael Dettogni Guariento, Adriano Caliman
      Despite the general acknowledgment of the role of niche and stochastic process in community dynamics, the role of species relative abundances according to both perspectives may have different effects regarding coexistence patterns. In this study, we explore a minimum probabilistic stochastic model to determine the relationship of populations relative and total abundances with species chances to outcompete each other and their persistence in time (i.e., unstable coexistence). Our model is focused on the effects drift (i.e., random sampling of recruitment) under different scenarios of selection (i.e., fitness differences between species). Our results show that taking into account the stochasticity in demographic properties and conservation of individuals in closed communities (zero-sum assumption), initial population abundance can strongly influence species chances to outcompete each other, despite fitness inequalities between populations, and also, influence the period of coexistence of these species in a particular time interval. Systems carrying capacity can have an important role in species coexistence by exacerbating fitness inequalities and affecting the size of the period of coexistence. Overall, the simple stochastic formulation used in this study demonstrated that populations initial abundances could act as an equalizing mechanism, reducing fitness inequalities, which can favor species coexistence and even make less fitted species to be more likely to outcompete better-fitted species, and thus to dominate ecological communities in the absence of niche mechanisms. Although our model is restricted to a pair of interacting species, and overall conclusions are already predicted by the Neutral Theory of Biodiversity, our main objective was to derive a model that can explicitly show the functional relationship between population densities and community mono-dominance odds. Overall, our study provides a straightforward understanding of how a stochastic process (i.e., drift) may affect the expected outcome based on species selection (i.e., fitness inequalities among species) and the resulting outcome regarding unstable coexistence among species.

      PubDate: 2017-02-04T18:55:07Z
      DOI: 10.1016/j.actao.2017.01.004
      Issue No: Vol. 79 (2017)
       
  • The role of nurse functional types in seedling recruitment dynamics of
           alternative states in rangelands
    • Authors: Dardo R. López; Laura Cavallero
      Pages: 70 - 80
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Dardo R. López, Laura Cavallero
      In arid ecosystems, recruitment dynamics are limited by harsh environmental conditions and greatly depend on the net outcome of the balance between facilitation and competition. This outcome can change as a consequence of degradation caused by livestock overgrazing. Also, distinct plant species may show a differential response to a common neighbour under the same environmental conditions. Therefore, ecosystem degradation could affect the net balance of plant-plant interactions, which can also depend on the functional traits of potential nurse species. The aim of this study is to assess the influence of alternative degradation states on (i) the density of seedlings of perennial species emerging in four microsite types, and on (ii) the relative interaction intensity (RII) between seedlings and potential nurses belonging to three functional types (deep- and shallow-rooted shrubs, and tussock grasses). During three years, we recorded seedling density of perennial species in four alternative degradation states in grass-shrubby steppes from northwestern Patagonia. The density of emerged seedlings of perennial species decreased sharply as degradation increased, showing non-linear responses in most microsites. Seedling density underneath deep-rooted shrubs was higher than underneath shallow-rooted shrubs and tussock grasses. Also, deep-rooted shrubs were the only functional type that recorded seedling emergence in highly degraded states. Deep-rooted shrubs had facilitative effects on the seedlings emerging and surviving underneath them, independently of ecosystem degradation. In contrast, RII between shallow-rooted shrubs and recently emerged seedlings, switched from positive effects in the less degraded states, to negative effects in the most degraded state. Tussock grasses recorded the weakest intensity of facilitative interactions with recently emerged seedlings, switching to competitive interactions as degradation increased. Our results suggest that species with key functional traits should be considered in management and restoration plans for rangelands with different degradation levels, since they have a strong influence in the net outcome of plant-plant interactions and in the recruitment dynamics of arid ecosystems.

      PubDate: 2017-02-18T07:26:14Z
      DOI: 10.1016/j.actao.2017.01.003
      Issue No: Vol. 79 (2017)
       
  • Scavenging efficiency and red fox abundance in Mediterranean mountains
           with and without vultures
    • Authors: Zebensui Morales-Reyes; José A. Sánchez-Zapata; Esther Sebastián-González; Francisco Botella; Martina Carrete; Marcos Moleón
      Pages: 81 - 88
      Abstract: Publication date: February 2017
      Source:Acta Oecologica, Volume 79
      Author(s): Zebensui Morales-Reyes, José A. Sánchez-Zapata, Esther Sebastián-González, Francisco Botella, Martina Carrete, Marcos Moleón
      Vertebrate scavenging assemblages include two major functional groups: obligate scavengers (i.e., vultures), which depend totally on carrion and are undergoing severe declines around the globe, and facultative scavengers, which exploit carrion opportunistically and are generally ubiquitous. Our goal was to investigate the hypothesis that vultures can indirectly regulate the abundance of mesopredators (i.e., facultative scavengers) through modulating their access to carrion resources. We studied scavenging efficiency and red fox (Vulpes vulpes) abundance in two neighbouring areas of South-eastern Spain where vultures (mainly griffon vultures Gyps fulvus) are present (Cazorla) and absent (Espuña). To do so, we monitored ungulate carcasses consumption during winter and summer, and counted red fox scats along walking transects as a proxy of fox density. Our results confirmed that scavenging efficiency was higher in Cazorla and in carcasses visited by vultures. This resulted in increasing scavenging opportunities for facultative scavengers where vultures were absent. Accordingly, mean red fox abundance was higher in Espuña. These results suggest the existence of a vulture-mediated mesopredator release (i.e., an increase of mesopredator numbers following vulture loss), which could trigger important indirect ecological effects. Also, our study demonstrates that facultative scavengers are hardly able to functionally replace vultures, mainly because the former exploit carrion on a slower time scale.

      PubDate: 2017-02-18T07:26:14Z
      DOI: 10.1016/j.actao.2016.12.012
      Issue No: Vol. 79 (2017)
       
  • Nest site preferences of the Woodlark (Lullula arborea) and its
           association with artificial nest predation
    • Authors: Roman Buehler; Laura Bosco; Raphaël Arlettaz; Alain Jacot
      Pages: 41 - 46
      Abstract: Publication date: January 2017
      Source:Acta Oecologica, Volume 78
      Author(s): Roman Buehler, Laura Bosco, Raphaël Arlettaz, Alain Jacot
      The Woodlark is an insectivorous bird, which is listed as a priority species in Switzerland. In Valais, a stronghold of this species in the country, the birds breed in intensively managed vineyards and show a preference for parcels with ground vegetation during territory establishment. As a ground-breeder, the species is highly vulnerable to nest predation by avian and mammal predators. The aims of our study were firstly to investigate nest site preferences of the woodlark within vineyards and secondly to compare the predation risk of artificial nests dependent of ground vegetation structure. Our results point out that the Woodlark prefers patches of tall and dense ground cover within vegetated vineyard parcels and avoids parcels that have been treated with herbicides. In a follow-up experiment we conducted a study comparing the predation rate of artificial nests between bare parcels (<20% vegetated area) and vegetated parcels (>40% vegetated area). Artificial nests equipped with one quail egg were distributed pairwise between two adjacent parcels that fulfilled the upper criteria and were monitored by trail cameras during 10–12 days. Predation rate was generally low (4 predation events) and only occurred in bare parcels. These data indicate that conspicuousness of avian nests may be decreased in vegetated parcels and that the amount of vegetation can lower the predation risk on ground breeding birds - another indication for the importance of ground vegetation for a successful conservation of the endangered Woodlark in Swiss vineyards.

      PubDate: 2017-01-06T17:34:05Z
      DOI: 10.1016/j.actao.2016.12.004
      Issue No: Vol. 78 (2017)
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: July 2017
      Source:Acta Oecologica, Volume 82


      PubDate: 2017-06-22T01:20:11Z
       
  • Sugar secretion and ant protection in Ficus benguetensis: Toward a general
           trend of fig–ant interactions
    • Authors: Shang-Yang Lin; Lien-Siang Chou; Anthony Bain
      Abstract: Publication date: Available online 17 June 2017
      Source:Acta Oecologica
      Author(s): Shang-Yang Lin, Lien-Siang Chou, Anthony Bain
      The relationship between plants and ants is often mediated by the presence of extrafloral nectaries (EFNs) that attract ants and provide rewards by protecting plants from herbivores or parasites. Ficus trees (Moraceae) and their pollinators (Hymenoptera: Agaonidae) are parasitized by many nonpollinating fig wasp species (Hymenoptera: Chalcidoidea) that decrease the reproductive output of the mutualistic partners. Previous studies have shown that ants living on and patrolling Ficus species can efficiently deter parasitic wasps. The aim of this study was to verify the presence of EFNs on figs of Ficus benguetensis and test the hypothetical protection service provided by ants. Figs in different developmental stages were collected from Fu-Yang Eco Park, Taipei, Taiwan. Sugars on the fig surface were collected and analyzed through high-performance anion-exchange chromatography. Moreover, ants were excluded from the figs to determine the effect of ants on the nonpollinating fig wasps. We identified three oligosaccharides whose relative proportions varied with the fig developmental phase. In addition, results showed that the ant-excluded figs were heavily parasitized and produced three times less pollinators than did the control figs. Finally, the specific interactions of Ficus benguetensis with ants and the relationship between figs and ants in general are discussed.

      PubDate: 2017-06-22T01:20:11Z
      DOI: 10.1016/j.actao.2017.06.006
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: May 2017
      Source:Acta Oecologica, Volume 81


      PubDate: 2017-05-17T13:56:42Z
       
  • Host–parasitoid development and survival strategies in a
           non-pollinating fig wasp community
    • Authors: Pratibha Yadav; Renee M. Borges
      Abstract: Publication date: Available online 5 May 2017
      Source:Acta Oecologica
      Author(s): Pratibha Yadav, Renee M. Borges
      In a tritrophic system, parasitoid development and galler host survival strategies have rarely been investigated simultaneously, an approach crucial for a complete understanding of the complexity of host–parasitoid interactions. Strategies in parasitoids to maximize host exploitation and in gallers to reduce predation risk can greatly affect the structure of tritrophic communities. In this study, the developmental strategies of galler hosts and their associated parasitoids in the tritrophic fig–fig wasp system are experimentally investigated for the first time. In this highly co-evolved system, wasp development is intrinsically tied with the phenology of the wasp brood sites that are restricted to the enclosed urn-shaped fig inflorescence called the syconium which can be regarded as a microcosm. Wasp exclusion experiments to determine host specificity, gall dissections and developmental assays were conducted with non-pollinating fig wasps in Ficus racemosa. Our results provide evidence for exceptions to the widely accepted koinobiont–idiobiont parasitoid dichotomy. This is also the first time fig wasps were raised ex situ from non-feeding stages onwards, a technique that enabled us to monitor their development from their pre-pupal to adult stages and record their development time more accurately. Based on variation in development time and host specificity, the possibility of a cryptic parasitoid species is raised. The frequency of different wasp species eclosing from the microcosms of individual syconia is explained using host–parasitoid associations and interactions under the modulating effect of host plant phenology.
      Graphical abstract image

      PubDate: 2017-05-08T13:40:11Z
      DOI: 10.1016/j.actao.2017.04.001
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: April 2017
      Source:Acta Oecologica, Volume 80


      PubDate: 2017-04-12T10:55:53Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016