 Subjects -> CONSERVATION (Total: 128 journals)
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- Differential accumulation of cardenolides from Asclepias curassavica by
large milkweed bugs does not correspond to availability in seeds or
biological activity on the bug Na+/K+-ATPase
Authors: Paola Rubiano-Buitrago, Shrikant Pradhan, Veit Grabe, Alfonso Aceves-Aparicio, Christian Paetz, Hannah M. Rowland
Abstract: Milkweed–herbivore systems are characterized by cardenolide chemical defenses and specialized herbivore adaptations such as physiological target site insensitivity. Cardenolide defenses in milkweeds can vary in terms of the total concentration, differences in the polarity of individual cardenolides, and the substitution of the steroidal structures that can contribute to the molecule's reactivity. The variability in cardenolide defenses could represent the plant's response to natural selection and adaptation of resistant herbivores and is a characteristic of phenotype-matching between defensive and offensive traits resulting from coevolution. Here, we test the phenotypic match of the cardenolide composition of seeds of Asclepias curassavica and those sequestered by nymphs and adults of the specialized seed herbivore Oncopeltus fasciatus, combined with tests of the inhibitory capacity of a subset of seed cardenolides against the Na+/K+-ATPase of O. fasciatus and a non-adapted insect (Drosophila melanogaster). We compare this with the inhibitory capacity against the highly sensitive porcine Na+/K+-ATPase. Among the five most abundant cardenolides present in milkweed seeds, glucopyranosyl frugoside, glucopyranosyl gofruside, and glucopyranosyl calotropin were significantly more abundant in the seeds than in the adults and nymphs; the bugs contained higher concentrations of the deglucosylated compounds. The most abundant compound, glucopyranosyl frugoside, was also the most inhibitory for O. fasciatus, but O. fasciatus was significantly more tolerant to all compounds compared to D. melanogaster and the highly sensitive porcine enzyme. Our results add to the evidence that O. fasciatus sequesters specific individual cardenolides from its Asclepias host plants that are not directly linked to the concentration and inhibitory potency.
PubDate: 2023-06-08T00:00:00Z
- Genetic diversity and population structure of Epichloë fungal pathogens
of plants in natural ecosystems
Authors: Artemis D. Treindl, Jessica Stapley, Adrian Leuchtmann
Abstract: Understanding the population genetic processes driving the evolution of plant pathogens is of central interest to plant pathologists and evolutionary biologists alike. However, most studies focus on host-pathogen associations in agricultural systems of high genetic and environmental homogeneity and less is known about the genetic structure of pathogen populations infecting wild plants in natural ecosystems. We performed parallel population sampling of two pathogenic Epichloë species occurring sympatrically on different host grasses in natural and seminatural grasslands in Europe: E. typhina infecting Dactylis glomerata and E. clarkii infecting Holcus lanatus. We sequenced 422 haploid isolates and generated genome-wide SNP datasets to investigate genetic diversity and population structure. In both species geographically separated populations formed genetically distinct groups, however, population separation was less distinct in E. typhina compared to E. clarkii. The patterns of among population admixture also differed between species across the same geographic range: we found higher levels of population genetic differentiation and a stronger effect of isolation by distance in E. clarkii compared to E. typhina, consistent with lower levels of gene flow in the former. This pattern may be explained by the different dispersal abilities of the two pathogens and is expected to be influenced by the genetic structure of host populations. In addition, genetic diversity was higher in E. typhina populations compared to E. clarkii, indicative of higher effective population size in E. typhina. These results suggest that the effect of genetic drift and the efficacy of selection may differ in the two species. Our study provides evidence of how ecologically similar species occupying the same geographical space can experience different evolutionary contexts, which could influence local adaptation and co-evolutionary dynamics of these fungal pathogens.
PubDate: 2023-06-08T00:00:00Z
- Editorial: Can the trees save the crops' Predicting the services provided
Authors: Mário Santos, Maria Rosa Mosquera-Losada, Berta Gonçalves
PubDate: 2023-06-08T00:00:00Z
- Body condition and corticosterone stress response, as markers to
investigate effects of human activities on Adélie penguins (Pygoscelis
adeliae)|Introduction|Methods|Results|Discussion
Authors: Coline Marciau, Thierry Raclot, Sophie Bestley, Christophe Barbraud, Karine Delord, Mark Andrew Hindell, Akiko Kato, Charline Parenteau, Timothée Poupart, Cécile Ribout, Yan Ropert-Coudert, Frédéric Angelier
Abstract: IntroductionIn Antarctica, there is growing concern about the potential effect of anthropogenic activities (i.e., tourism, research) on wildlife, especially since human activities are developing at an unprecedented rate. Although guidelines exist to mitigate negative impacts, fundamental data are currently lacking to reliably assess impacts. Physiological tools, such as circulating corticosterone levels, appear promising to assess the potential impact of human disturbance on Antarctic vertebrates.MethodsIn this study, we compared the body condition, and the physiological sensitivity to stress (i.e., basal and stress-induced corticosterone level) of adult and chick Adélie penguins between a disturbed and an undisturbed area (i.e., 2 colonies located in the middle of a research station exposed to intense human activities and 2 colonies located on protected islands with minimal human disturbance).ResultsWe did not find any significant impact of human activities on body condition and corticosterone levels in adults (incubating adults, brooding adults). In chicks, there were significant inter-colony variations in stress-induced corticosterone levels. Specifically, the chicks from the disturbed colonies tended to have higher stress-induced corticosterone levels than the chicks from the protected areas although this difference between areas was not significant. In addition, and independently of human disturbance we also found significant differences in adult body condition, and chick corticosterone level between colonies.DiscussionOverall, our study suggests that this species is not dramatically impacted by human activities, at least when humans and penguins have cohabited for several decades. Our results support therefore the idea that this species is likely to be tolerant to human disturbance and this corroborates with the persistence of Adélie penguin colonies in the middle of the research station. However, our results also suggest that chicks might be more sensitive to human disturbance than adults and might therefore potentially suffer from human disturbance. Our study also suggests that specific individual and environmental variables outweigh the potential minor impact of human disturbance on these variables. Combining corticosterone with complementary stress-related physiological markers, such as heart rate, may strengthen further studies examining whether human disturbance may have subtle detrimental impacts on individuals.
PubDate: 2023-06-07T00:00:00Z
- Urban areas in rural landscapes – the importance of green space and
local architecture for bat conservation
Authors: Lisa Printz, Kirsten Jung
Abstract: Urbanization is a highly disperse process, resulting in urban sprawl across landscapes. Within such landscapes, structural heterogeneity may be an important factor for maintaining biodiversity. We investigated the importance of habitat heterogeneity on bats in villages across the Schwäbische Alb, Germany, a progressively urbanized region. Bat activity and diversity were assessed using acoustic monitoring. We characterized habitat composition at the local and neighborhood scale and assessed environmental characteristics of urban density, vegetation cover and architectural features, combining satellite and ground-based measures. Our results revealed that the extent of urban areas determines the occurrence of different bat species, while local spatial, structural, and architectonic parameters at recording sites affected bat activity, feeding activity and social encounters. Larger urban areas with increased proportion of impervious surfaces and newly constructed housing areas were associated with fewer bat species and lower bat activity. Bat activity and feeding were highest in housing areas constructed between 1950-2000 and increased with higher proportions of older, rather openly structured vegetation. Our results clearly show a combined importance of environmental parameters across spatial scales, affecting habitat suitability and quality of rural urban areas for bats. This highlights that strategies for biodiversity inclusion in rural urban planning need to consider both local and neighborhood conditions to support bat diversity and vital bat activity. In particular, it exemplifies future challenges to maintain biodiversity within progressively urbanized rural landscapes, as this needs support by municipalities for maintaining space for nature in areas designated for urban development and also the consciousness by local residents for biodiversity-friendly modernizations.
PubDate: 2023-06-07T00:00:00Z
- Ecological stoichiometric characteristics of three dominant fish species
from the Beibu Gulf: inter- and intraspecific variations
Authors: Caiguang Wang, Liang Zhu, Liangliang Huang, Hao Xu, Peng Xu, Xiongbo He, Yunrong Yan, Xi Yang, Asfandyar Shahab, Bin Kang
Abstract: In this study we explore the inter- and intraspecific variations in the ecological stoichiometry of three dominant fish species [Saurida tumbil (n = 33), Pennahia macrocephalus (n = 34), and Upeneus sulphureus (n = 32)] from the Beibu Gulf, the contents of carbon (C), nitrogen (N), phosphorus (P), calcium (Ca), δ13C, and δ15N in fishes were analyzed. Results illustrated that the ranges of elemental variations (C, N, P, and Ca) in the three fishes were 36.73∼49.24%, 8.79∼13.99%, 1.11∼2.78%, and 1.16∼4.58%, respectively while P content varied the most, resulting in variations in C:P and N:P in fishes. Correlation analysis determined the association among various parameters and illustrated that Ca content was significantly positively correlated with P content, which indicated that P content variation was attributed to the formation of fish bones and scales. The C, N, and P contents and their ratios were significantly correlated with body length and δ13C in the three fishes, indicating that the changes in C:N:P concentrations are due to individual development and food sources. Significant inter- and intraspecific differences in the body stoichiometry of the three fishes were found in this study, mainly due to differences in body size and diet. The aquatic organisms underwent individual development fluctuations in morphology and diet, which consequently altered their stoichiometric features.
PubDate: 2023-06-07T00:00:00Z
- Harnessing iNaturalist to quantify hotspots of urban biodiversity: the Los
Angeles case study|Introduction|Methods|Results|Discussion
Authors: Joscha Beninde, Tatum W. Delaney, Germar Gonzalez, H. Bradley Shaffer
Abstract: IntroductionA major goal for conservation planning is the prioritized protection and management of areas that harbor maximal biodiversity. However, such spatial prioritization often suffers from limited data availability, resulting in decisions driven by a handful of iconic or endangered species, with uncertain benefits for co-occurring taxa. We argue that multi-species habitat preferences based on field observations should guide conservation planning to optimize the long-term persistence of as many species as possible.MethodsUsing habitat suitability modeling techniques and data from the community-science platform iNaturalist, we provide a strategy to develop spatially explicit models of habitat suitability that enable better informed, place-based conservation prioritization. Our case study in Greater Los Angeles used Maxent and Random Forests to generate suitability models for 1,200 terrestrial species with at least 25 occurrence records, drawn from plants (45.5%), arthropods (27.45%), vertebrates (22.2%), fungi (3.2%), molluscs (1.3%), and other taxonomic groups (< 0.3%). This modeling strategy further compared spatial thinning and taxonomic bias file corrections to account for the biases inherent to the iNaturalist dataset, modeling species jointly and separately in wildland and urban sub-regions and validated model performance using null models and a “test” dataset of species and occurrences that were not used to train models.ResultsMean models of habitat suitability of all species combined were similar across model settings, but the mean Random Forest model received the highest median AUCROC and AUCPRG scores in model evaluation. Taxonomic groups showed relatively modest differences in their response to the urbanization gradient, while native and non-native species showed contrasting patterns in the most urban and the most wildland habitats and both peaked in mean habitat suitability near the urban-wildland interface.DiscussionOur modeling framework is based entirely on open-source software and our code is provided for further use. Given the increasing availability of urban biodiversity data via platforms such as iNaturalist, this modeling framework can easily be applied to other regions. Quantifying habitat suitability for a large, representative subset of the locally occurring pool of species in this way provides a clear, data-driven basis for further ecological research and conservation decision-making, maximizing the impact of current and future conservation efforts.
PubDate: 2023-06-06T00:00:00Z
- An artificial intelligence-based assessment of soil erosion probability
indices and contributing factors in the Abha-Khamis watershed, Saudi
Arabia
Authors: Saeed Alqadhi, Javed Mallick, Swapan Talukdar, Meshel Alkahtani
Abstract: Soil erosion is a major problem in arid regions, including the Abha-Khamis watershed in Saudi Arabia. This research aimed to identify the soil erosional probability using various soil erodibility indices, including clay ratio (CR), modified clay ratio (MCR), Critical Level of Soil Organic Matter (CLOM), and principle component analysis based soil erodibility index (SEI). To achieve these objectives, the study used t-tests and an artificial neural network (ANN) model to identify the best SEI model for soil erosion management. The performance of the models were then evaluated using R2, Root Mean Squared Error (RMSE), Mean Squared Error (MSE), and Mean Absolute Error (MAE), with CLOM identified as the best model for predicting soil erodibility. Additionally, the study used Shapley additive explanations (SHAP) values to identify influential parameters for soil erosion, including sand, clay, silt, soil organic carbon (SOC), moisture, and void ratio. This information can help to develop management strategies oriented to these parameters, which will help prevent soil erosion. The research showed notable distinctions between CR and CLOM, where the 25–27% contribution explained over 89% of the overall diversity. The MCR indicated that 70% of the study area had low erodibility, while 20% had moderate and 10% had high erodibility. CLOM showed a range from low to high erodibility, with 40% of soil showing low CLOM, 40% moderate, and 20% high. Based on the T-test results, CR is significantly different from CLOM, MCR, and principal component analysis (PCA), while CLOM is significantly different from MCR and PCA, and MCR is significantly different from PCA. The ANN implementation demonstrated that the CLOM model had the highest accuracy (R2 of 0.95 for training and 0.92 for testing) for predicting soil erodibility, with SOC, sand, moisture, and void ratio being the most important variables. The SHAP analysis confirmed the importance of these variables for each of the four ANN models. This research provides valuable information for soil erosion management in arid regions. The identification of soil erosional probability and influential parameters will help to develop effective management strategies to prevent soil erosion and promote agricultural production. This research can be used by policymakers and stakeholders to make informed decisions to manage and prevent soil erosion.
PubDate: 2023-06-06T00:00:00Z
- Seasonal dynamics of sediment organic carbon storage for the upper streams
of the Yangtze River|Introduction|Methods|Results|Discussion
Authors: Jianfeng Hou, Fei Li, Zhihui Wang, Xuqing Li, Rui Cao, Wanqin Yang
Abstract: IntroductionForest streams reserve more than 90% of the organic carbon (OC) in sediments, thus playing crucial roles in the global carbon cycle. Although forest streams are widely distributed across various forest regions, seasonal dynamics of OC in forest sediments have not been fully investigated.MethodsHere, we sampled soils (0–5 cm) in 15 representative forest stream sediments for 5 critical periods (snowmelt season, early growing season, growing season, late growing season, and seasonal snow cover season) during a one-year investigation in a geologically fragile subalpine coniferous forest catchment in the upper reaches of the Yangtze River in Sichuan province and the OC concentrations were measured by potassium dichromate external heating method.ResultsThe OC concentration of stream sediments ranged from 6.39 to 458.93 g kg−1, and the average was 84.56 g kg−1 for 15 streams in 5 critical periods during a 1-year investigation. Correspondingly, their stocks ranged from 2.05 to 310.56 kg m−2, and the average was 46.03 kg m−2. The maximum and minimum OC stocks were consistently observed during the late growing season and the snowmelt season, respectively. Otherwise, the OC stocks ranged from 1.31 to 218.05, 1.29 to 182.64, and 0.99 to 190.38 kg m−2 for the upstream, midstream, and downstream sediments, and the average was 39.36, 36.58, and 37.93 kg m−2, respectively. The average ratios of the OC stocks of the upstream and downstream ranged from 0.10–6.31, with an average of 1.43, during 5 critical periods, which indicated that the forest stream sediments may play crucial roles as carbon sources.DiscussionFurthermore, based on regression analysis, we found that the seasonal dynamics of OC concentrations and stocks were mainly regulated by precipitation, temperature, sediment depth, and litter carbon input to the streams together. These findings demonstrate that forest stream sediments may play crucial roles in the carbon biogeochemical cycle of subalpine forests and adjoining streams.
PubDate: 2023-06-06T00:00:00Z
- A three-step approach for co-locating nature-based solutions within
offshore wind farms
Authors: Emma Jane Rendle, Emily Louise Hunt, Anthony William James Bicknell
Abstract: The extent of seabed licensed for offshore renewables is being expanded with the global requirement to reduce carbon emissions. The opportunity for Nature-based Solutions for restoration, conservation, mariculture, infrastructure protection, and carbon sequestration initiatives are being explored internationally. Co-location of marine renewable or structures with conservation initiatives offers the opportunity to support populations of threatened species and contribute to wider ecosystem services and benefits. Building on experience from a North Sea project, we explore the feasibility to co-locate bivalve species at offshore wind farms. We present a three-step approach to identify offshore wind farm sites with the potential to co-locate with compatible species within a marine licensed area, based on environmental and physical conditions and biological tolerances. These steps are, (1) information collection and data synthesis, (2) data analysis through site suitability and species compatibility assessments, and (3) numerical modelling approaches to test the feasibility of pilot studies and scale-up planned operations. This approach supports feasibility assessment by identification of sites where Nature-based Solution project success is more likely or certain, thereby reducing project costs and risk of failure. An example case study is provided using Gunfleet Sands offshore wind farm (southeast England) and the restoration and conservation of the commercially valuable European Flat Oyster (Ostrea edulis).
PubDate: 2023-06-05T00:00:00Z
- A precise forest spatial structure investigation using the SLAM+AR
technology|Introduction|Methods|Results|Discussion
Authors: Fei Yan, Tianshuo Guan, Mohammad Rahmat Ullah, Li Gao, Yongxiang Fan
Abstract: IntroductionForest spatial structures are the foundations of the structure and function of forest ecosystems. Quantitative descriptions and analyses of forest spatial structure have recently become common tools for digitalized forest management. Therefore, the accuracy and intelligence of acquiring forest spatial structure information are of great significance.MethodsIn this study, we developed a forest measurement system using a mobile phone. Through this system, the following tree measurements can be achieved: (1) point cloud of tree and chest diameter circle to measure tree diameter at breast height (DBH) and position coordinates of tree by using simultaneous localization and mapping (SLAM) technology, (2) virtual boundary creation of the sample plot, and the auxiliary measurement function of tree with the augmented reality (AR) interactive module, and (3) position coordinates and single-tree volume factor to calculate the spatial structural parameters of the forest (e.g., Mingling degree, Dominance index, Uniform angle index, and Crowdedness index).The system was tested in three 32 x 32 martificial forest plots.ResultsThe average DBH estimations showed BIAS of -0.47 to 0.45 cm and RMSEs of 0.57 to 0.95 cm. Its accuracy level met the requirements of forestry sample surveys. The tree position estimates for the three plots had relatively small RMSEs with 0.17 to 0.22 m on the x-axis and 0.16 to 0.26 m on the y-axis. The spatial structural parameters were as follows: the mingling degree of plot 1 was 0.32, and the overall mixing degree of tree species was low. The trees in plots 2 and 3 were all single species, and the mixing degree of both plots was 0. The dominance index of the three plots was 0.56, 0.51, and 0.51, indicating that the competitive advantage of the whole orest species was not obvious. The uniform angle index of the three plots was 0.55, 0.59, and 0.61, indicating that the positions of trees in the three plots were randomly distributed. The crowdedness index of plot 1 was 1.03, indicating that the degree of aggregation of the trees was low and showed a random distribution trend. The crowdedness index of the other plots were 1.36 and 1.40, indicating that the trees in the plots show a trend of uniform distribution, and the uniformity of plot 3 is higher than that of plot 2, but the overall uniformity is relatively weak.DiscussionThe findings of this study provide support for the optimization of forest structures and improve our conceptual understanding of forest community succession and restoration, in addition to the informatization and precision of forest spatial structure surveys.
PubDate: 2023-06-05T00:00:00Z
- Does environmental information disclosure drive corporate sustainable
growth' A new insight into U-shaped relationship
Authors: Jinsong Zhang, Mengmeng Wang
Abstract: Due to the increasing rate of economic development and the increasingly serious problem of environmental degradation, environmental information disclosure has become an important basis for promoting carbon peaking and carbon neutrality, and an important way for enterprises to carry out green governance to achieve sustainable development. This study uses empirical research methods to analyze the relationship between environmental information disclosure and corporate sustainable growth in the context of green governance using panel data of Chinese A-share listed companies in Shanghai and Shenzhen from 2012 to 2021. The empirical tests conclude that there is a U-shaped relationship between environmental information disclosure and corporate sustainable growth, which decreases and then increases, and the U-shaped relationship is transmitted through innovation inputs. The U-shaped relationship between environmental information disclosure and corporate sustainable growth is weakened by firm size and enhanced by equity incentives. In addition, further group analysis reveals that the above U-shaped relationship is more significant in non-state enterprises than in state-owned enterprises.
PubDate: 2023-06-05T00:00:00Z
- The pygidial gland secretion of Laemostenus punctatus (Coleoptera,
Carabidae): a source of natural agents with antimicrobial, anti-adhesive,
and anti-invasive activities
Authors: Marija Nenadić, Dejan Stojković, Marina Soković, Ana Ćirić, Ivica Dimkić, Tamara Janakiev, Nikola Vesović, Ljubodrag Vujisić, Marina Todosijević, Saša S. Stanković, Nina B. Ćurčić, Uroš Milinčić, Dragan Petrović, Miroljub Milinčić, Srećko Ćurčić
Abstract: In the present study, we investigated in vitro the antimicrobial activity of the pygidial gland secretion of the guanophilic ground beetle Laemostenus (Pristonychus) punctatus (Dejean, 1828) and some of its chemicals against resistant and non-resistant bacteria and Candida species, the synergistic and additive potential of combinations of selected chemicals and antimicrobial drugs against resistant bacterial and fungal strains, anti-adhesive and anti-invasive potential of the secretion and formic acid alone and in selected combinations with antimicrobial drugs against methicillin-resistant Staphylococcus aureus (MRSA) toward spontaneously immortalized human keratinocyte cell line (HaCaT cells). In addition, we examined the antiproliferative activity of the secretion and formic acid in vitro. The tested secretion and the standards of formic and oleic acids possessed a significant level of antimicrobial potential against all tested strains (P < 0.05). The isolate from guano Pseudomonas monteilii showed the highest resistance to the secretion and formic acid, while MRSA achieved a significantly high level of susceptibility to all agents tested, particularly to the combinations of formic acid and antibiotics, but at the same time showed a certain level of resistance to the antibiotics tested individually. Candida albicans and C. tropicalis were found to be the most sensitive fungal strains to the secretion. Formic acid (MIC 0.0005 mg/mL) and gentamicin (MIC 0.0010 mg/mL) in the mixture achieved synergistic antibacterial activity against MRSA (FICI = 0.5, P < 0.05). The combination of formic acid, gentamicin and ampicillin accomplished an additive effect against this resistant bacterial strain (FICI = 1.5, P < 0.05). The secretion achieved a better inhibitory effect on the adhesion ability of MRSA toward HaCaT cells compared to formic acid alone, while formic acid showed better results regarding the invasion (P < 0.001). The combinations of gentamicin and ampicillin, as well as of formic acid and gentamicin and ampicillin achieved similar anti-adhesive and anti-invasive effects, with a slight advantage of formic acid and antibiotics in combination (P < 0.001). The secretion and formic acid were found to be non-toxic to HaCaT cells in vitro (IC50 ≥ 401 μg/mL).
PubDate: 2023-06-02T00:00:00Z
- A dynamic framework for assessing and managing risks to ecosystems from
fisheries: demonstration for conserving the krill-based food web in
Antarctica
Authors: Andrew J. Constable, So Kawaguchi, Michael Sumner, Philip N. Trathan, Victoria Warwick-Evans
Abstract: The ecosystem approach to fisheries has been discussed since the 1980s. It aims to reduce risks from fisheries to whole, or components of, ecosystems, not just to target species. Precautionary approaches further aim to keep the risk of damage to a low level. Here, we provide a dynamic framework for spreading the ecosystems risk of fisheries in space and time, a method that can be used from the outset of developing fisheries and continually updated as new knowledge becomes available. Importantly, this method integrates qualitative and quantitative approaches to assess risk and provides mechanisms to both spread the risk, including enabling closed areas to help offset risk, and adjust catch limits to keep regional risk to a baseline level. Also, the framework does not require uniform data standards across a region but can incorporate spatially and temporally heterogeneous data and knowledge. The approach can be coupled with the conservation of biodiversity in marine protected areas, addressing potential overlap of fisheries with areas of high conservation value. It accounts for spatial and temporal heterogeneity in ecosystems, including the different spatial and temporal scales at which organisms function. We develop the framework in the first section of the paper, including a simple illustration of its application. In the framework we include methods for using closed areas to offset risk or for conserving biodiversity of high conservation value. We also present methods that could be used to account for uncertainties in input data and knowledge. In the second section, we present a real-world illustration of the application of the framework to managing risks of food web effects of fishing for Antarctic krill in the Southern Ocean. Last, we comment on the wider application and development of the framework as information improves.
PubDate: 2023-06-02T00:00:00Z
- Spatial and temporal characteristics of carbon emission and sequestration
of terrestrial ecosystems and their driving factors in mainland China—a
case study of 352 prefectural administrative
districts|Introduction|Methods|Results|Discussion
Authors: Jingyuan Lin, Yi Guo, Jiayan Li, Ming Shao, Peng Yao
Abstract: IntroductionGlobal climate change, increase in human activities, and prominence of ecological issues have led to uneven quantitative and spatial distributions of carbon emission and sequestration of terrestrial ecosystems. Such uneven distributions can lead to more negative impacts on the natural environment and human living conditions.MethodsTherefore, based on the carbon neutralization policy, we conducted geographically weighted regression (GWR) modeling in this study using panel data from 352 Chinese prefectural administrative districts in 2000, 2005, 2010, and 2017 to analyze and determine the impact factors and their spatial distribution for carbon emission and sequestration of terrestrial ecosystems.ResultsOur results showed that total population (TP), per capita gross domestic product (GDP) (PCG), proportion of secondary industry output (PSIO), scale of urban built-up area (SUB), green space proportion in city areas (GSP), normalized difference vegetation index (NDVI), and temperature (TEM) are factors driving carbon sequestration and carbon emission. The spatial distribution of these driving factors in mainland China is: (1) TP showed a negative correlation to carbon emission in most areas, while it exhibited a positive correlation to carbon sequestration in the southern, southwestern, and western parts of northwest China; however, in all other areas, TP showed a negative correlation with carbon sequestration; (2) PCG was positively correlated to carbon emission in most areas of China and to carbon sequestration in southwest, south, central, and northeast China; however, PCG demonstrated a negative correlation to carbon sequestration in the remaining areas; (3) PSIO and SUB presented a positive correlation to carbon emission and a negative correlation to carbon sequestration in most areas; (3) In contrast, GSP showed a negative correlation to carbon emission and a positive correlation to carbon sequestration in most areas; (5)NDVI showed a negative correlation to carbon emission and carbon sequestration in most areas toward the east of the “Heihe-Tengchong Line”; NDVI was positively correlated to both carbon emission and sequestration toward the west of this line; (6)TEM was positively correlated to carbon emission and sequestration in most parts of China.DiscussionBased on these results, we further divided the Chinese cities into 6 groups: (1) Groups 1, 2, 3, and 6 are areas where carbon emission and sequestration are governed by both socioeconomic and natural ecological factors. The major driving factors of carbon emission and carbon sequestration in group 1 are PSIO, GSP, and NDVI; the driving factors of group 2 are SUB and NDVI. Meanwhile, carbon emission and sequestration in group 3 are governed by PCG, GSP, and NDVI; for group 6, carbon emission and sequestration are controlled by PCG, SUB, GSP, and NDVI; (2) Group 4 represents areas where carbon emission and sequestration are majorly impacted by PCG and SUB, thereby rendering socioeconomic factors as the major driving forces. Group 5 represents areas where carbon emission and sequestration are sensitive to the natural environment, with GSP and NDVI being the driving factors. Considering the uneven distribution of carbon sequestration and emission and the diverse driving factors in different areas of China, we provided guidance for future environmental policies aimed at reducing the uneven distribution of carbon sequestration and emission in different areas to achieve carbon neutralization.
PubDate: 2023-06-02T00:00:00Z
- ANN-based prediction of ammonia nitrogen for wastewater discharge
indicators under carbon neutral trend|Introduction|Methods|Results and
discussion
Authors: Hongbo Liu, Haoran Jian
Abstract: IntroductionWith the rapid development of society and urbanization, greenhouse gas emissions have increased, leading to environmental problems such as global warming. The rise in urban water consumption has also resulted in increased sewage discharge, exacerbating freshwater scarcity and water pollution. Understanding the current status and spatial distribution of greenhouse gas emissions in China's sewage treatment industry is crucial for emission reduction measures and controlling ammonia nitrogen pollution.MethodsThis study comprehensively investigates greenhouse gas emissions from sewage treatment plants, analyzing influencing factors and predicting future spatial and temporal distributions. The uncertainty of ammonia nitrogen emissions is calculated using the IPCC's error propagation method, considering uncertainty ranges of variables. Additionally, an artificial neural network is employed to predict ammonia nitrogen content in sewage discharge, aiming to prevent excessive levels in wastewater.Results and discussionThe proposed model outperforms others with an R-Squared score of 0.926, demonstrating its superior accuracy in predicting ammonia content in wastewater. These findings contribute to better emission reduction strategies and control of ammonia nitrogen emissions. This model can effectively prevent excessive ammonia nitrogen content in discharged wastewater, contributing to water pollution control. In conclusion, this study highlights the importance of understanding greenhouse gas emissions from sewage treatment plants and their impact on water pollution. The research provides valuable insights into emission reduction measures, emission prediction, and technological innovations suitable for China's specific conditions. By effectively managing ammonia nitrogen emissions and adopting the proposed predictive model, the goals of carbon neutrality and environmental sustainability can be better achieved.
PubDate: 2023-06-02T00:00:00Z
- Multi-scenario simulation analysis of cultivated land based on PLUS
model—a case study of Haikou, China
Authors: Xiaofu Lin, Hui Fu
Abstract: Land-use changes have received increasing attention since the 1990s. Cultivated land is a vital land resource with both natural and economic features. Socioeconomic development profoundly affects the spatiotemporal evolution of cultivated land. In turn, the spatiotemporal change of cultivated land also reflects the socioeconomic development trend. This study took Haikou City, which has the highest degree of urbanization in Hainan Province, as the study area, analyzed the spatiotemporal evolution characteristics of its cultivated land resources during the past 20 years of rapid socioeconomic development, and predicted the future spatiotemporal evolution trends of its cultivated land resources on this basis, to provide scientific reference for the rational use and sustainable development of the cultivated land resources in Haikou. This study applied the single land-use dynamic degree (SLUDD) and land-use transfer matrix to explore the spatiotemporal evolution of cultivated land in Haikou from 2000 to 2020. The patch-generating land-use simulation (PLUS) model was introduced to predict the patterns of cultivated land under different development scenarios in 2030. The results showed that: (1) although rapid socioeconomic development has contributed to Haikou's urbanization rate over the past 20 years, the accompanying expansion of construction land has caused damage to cultivated land resources, especially in urban suburbs. Site conditions, differential land benefits, and urban economic radiation may be potential influencing factors leading to the loss of peri-urban cultivated land; (2) it was verified that the PLUS model applies to the land-use patterns prediction in Haikou; and (3) the simulation results of both natural and urban development scenarios not only predicted the continued loss of cultivated land in the original zone but also exposed new sites of cultivated land loss. Although construction land expansion is an inevitable trend, there is still hope that the expansion rate can be controlled, for example, under the cultivated land conservation scenario. The simulation results of the three scenarios have essential reference values for the future maintenance of cultivated land resource security in Haikou.
PubDate: 2023-06-02T00:00:00Z
- Assembling animals: trees, genomes, cells, and contrast to plants
Authors: Jordi Paps, Maria Eleonora Rossi, Alexander M. C. Bowles, Marta Álvarez-Presas
Abstract: The Animal Kingdom is an astonishingly diverse group. Together with plants and fungi is one of the three major lineages of multicellular eukaryotes. Due to anthropocentrism and/or genuine scientific interest, their origin and diversification are pivotal to modern evolutionary biology. In the last few decades, dramatic technological advances in molecular biology and computational power have generated new phylogenetic proposals, as well as new tools to compare genomes or study cell type evolution. These new approaches complement the insights from fields such as comparative morphology, evodevo, or palaeontology, which all together provide an integrative view of animal evolution, including major evolutionary transitions such as the origin of animals or the emergence of animals with bilateral symmetry. In this paper, we review recent developments in animal phylogenetics, comparative genomics, and cell type evolution related to these two transitions, and we compare animals to another major lineage of multicellular eukaryotes, plants.
PubDate: 2023-06-02T00:00:00Z
- The constructive evolution of taste in Astyanax cavefish: A review
Authors: Daniel Berning, Joshua B. Gross
Abstract: Animals inhabiting subterranean environments tend to evolve a constellation of ‘regressive’ and ‘constructive’ features. Regressive traits like vision and pigmentation are reduced or lost in derived organisms. In contrast, constructive traits like non-visual sensation, are commonly augmented and evolving under strong selection. Numerous studies have examined the genetic, developmental and molecular bases for regressive traits, while constructive traits have received less attention. A key constructive sensory feature in cave animals is the gustatory system which is likely useful for animals living in complete darkness, given the need to secure food for survival. Interestingly, despite having been studied for decades in the Mexican tetra, Astyanax mexicanus, much remains unknown regarding the biological basis, and adaptive relevance, of taste system evolution in cave morphs. Here, we present a brief review of taste system research in this system, conducted over the past ~90 years. We underscore key differences in gustation between cave and surface fish that reside at the levels of anatomy, perception and behavior. From this review, we sought to identify key knowledge gaps in our understanding of constructive taste system evolution. Future studies will provide further insights to the nature of constructive trait evolution by determining if constructive and regressive traits evolve through similar or different genetic and developmental mechanisms, and provide an essential case study for examining convergence of constructive traits across geographically distinct populations.
PubDate: 2023-06-02T00:00:00Z
- Physiological and developmental mechanism of regressive molt in a
damp-wood termite Hodotermopsis sjostedti
Authors: Kenta Kobayashi, Kohei Oguchi, Toru Miura
Abstract: In some species of termites, a part of nymphs can undergo “regressive molt,” in which imaginal characters such as wing buds and body size are reduced. The function of regressive molt is thought to be a regulatory mechanism controlling caste composition in a colony. However, little is known about the physiological and developmental processes resulting in the regressive molt. In this study, therefore, regressive molt was observed in a damp-wood termite Hodotermopsis sjostedti, under rearing conditions, and histological and morphological observations during regressive molt (especially the reduction of wing buds) were carried out. It was found that nymphs with wing buds were classified into three morphological types. Almost all nymphs with swollen wing buds (Type 1) differentiated into alates, while nymphs with pigmented wing buds (Type 2) or with flat wing buds (Type 3) underwent regressive molts to become pseudergates (workers). Through the regressive molt, a part of nymphs differentiated into presoldiers or neotenic reproductives. Histological observations showed that, in nymphs undergoing regressive molt, epithelial tissue of wing buds was degenerated. Consistently, real-time qPCR analyses revealed that, apoptosis-related factors were up-regulated in the thoracic parts of Type 3 nymphs. Furthermore, expression analyses on developmental and endocrine factors by real-time qPCR were carried out, showing that, the expression pattern of these factors in regressive molt is nearly identical to that in stationary molt. These results suggest that the differentiation fate of nymph is determined during the intermolt period before the differentiation into Type 1 or Type 2/3 nymphs. The regressive molt itself would be almost identical to stationary molt.
PubDate: 2023-06-02T00:00:00Z
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