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1.
Science ; 367(6478): 626-627, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32029614
2.
J Environ Manage ; 259: 109626, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32072960

RESUMO

Integrated Water Resources Management (IWRM) in the social, economic and environmental aspect is widely accepted although still represents a big challenge for its implementation in global, regional and local scales. This is particularly important in the situation of new investments. In the case of already existing hydro-technical facilities, which were built at the end of the nineties of the last century, water management takes into account only the ecological awareness for their design and social participation is limited to acceptance of the local community. The Msciwojów retention reservoir analysed in the article is an example of an object whose project included ecological solutions aimed at ensuring high water quality, and its construction was approved and supported by the local community. At present, the reservoir does not function in accordance with the adopted assumptions, and water management requires the implementation of system solutions that take into account contradicting expectations of users and stakeholders of the reservoir. The current situation can be categorized as a wicked problem. The article presents a proposal to solve the situation on the basis of a participatory approach involving stakeholders through social learning as a part of the reservoir management system. The system approach was developed based on the principles of Soft Systems Methodology (SSM) and 10 Steps Planning Processing by Wilhite while using the causal loop diagrams (CLD). The result is an organizational model of the reservoir management structure and framework methodology for building solution scenarios. The key assumption of the proposed approach is the cyclicality of activities as part of the management process taking into account changes in the reservoir system and its settings in the social, economic and environmental aspects.


Assuntos
Recursos Hídricos , Água , Ecologia , Qualidade da Água , Abastecimento de Água
3.
J Environ Manage ; 255: 109925, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32063306

RESUMO

The Bashang Plateau, which is an ecologically fragile agro-pastoral zone in Hebei Province in China, plays an important role in protecting the Beijing-Tianjin-Hebei region from wind and sand erosion. Over the last four decades, it has been the target of extensive afforestation campaigns to promote improved ecosystem services. Though the benefits and costs of afforestation and its effectiveness within forestry have been widely investigated, few studies have focused on local households' willingness to accept (WTA) compensation relating to afforestation policies. Moreover, despite their importance in ensuring effective afforestation policies, the factors influencing WTA values have seldom been examined. We administered a direct questionnaire survey of households on the Bashang Plateau and applied a contingent valuation analysis to estimate their WTA values for compensation associated with ecological protection policies. We obtained 249 valid questionnaires, evidencing a high response rate (92.22%). New indicators of factors influencing respondents' WTA has been conducted including social, economic and ecological aspects, especially the improvement of ecological factors which consists of respondents' perceptions regarding the importance of ES and their satisfaction levels, and other environmental awareness factors. Additionally, in the case where many studies performed only one single regression analysis, this study performed a two-stage regression analysis and compared the results with those obtained using the Tobit model. A reasonable compensation standard facilitates a positive relationship between economic development and protection of natural environments. The findings showed that a certain amount of compensation (approximately 477.91 CNY/mu/year) was likely to prompt households' participation in afforestation projects. Compared with compensation standards for other ecological projects, the reported standard for afforestation projects on the Bashang Plateau is low, indicating that there is room for improvement. High annual household incomes are a key factor influencing households' WTA regarding their participation in afforestation activities. The results also revealed households' environmental awareness. Among respondents who participated in afforestation, those who valued forests for protecting environments and improving ecosystem services opted for lower compensation amounts. Our findings contribute valuable inputs for formulating ecological compensation standards and can serve as a reference for analyses of WTA and factors that drive it in other similar economically backward and ecologically fragile regions.


Assuntos
Ecologia , Ecossistema , Pequim , China , Conservação dos Recursos Naturais , Florestas
4.
J Environ Manage ; 255: 109875, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32063321

RESUMO

Countries share responsibility for the management and conservation of migratory bird species. However, a limited understanding of population dynamics hampers the implementation of harvest and transboundary management. Age-ratios and population density can be useful indicators to assess population dynamics to improve management and conservation actions. Here, the dynamics of an Atlantic population of Common quail Coturnix coturnix, using 32,508 quail samples and 4814 hunter questionnaires over a 20-year period (1996-2016) served as a comparative study for examining age-ratio patterns related to different geographic zones, population density and weather parameters. Results show that age-ratios varied over zones and years, specifically age-ratio 1 (AR1), used as an index of late breeding attempts, varied from 0.1 to 0.21. Age-ratio 2 (AR2), a surrogate of central recruitment, varied from 0.16 to 0.66. Finally, age-ratio 3 (AR3), used as an indicator of the population's annual breeding success, varied from 3.69 to 6.68. Age-ratio is linked to internal and external factors (i.e. effect of rainfall, variations over time and density-dependent relationships) depicting how quail age groups make segregated migration in time and space. Quail age groups perform a complex pattern of migration because of entwined changes in abundance, migration routes and timing, influencing population connectivity and dynamics. Our findings highlight the relevance of citizen science and transboundary agreements to improve management and conservation measures of migrant species. Administrations and policy-makers in developed and developing countries must coordinate efforts to engage hunters in a participatory management systems to achieve sustainability.


Assuntos
Migração Animal , Coturnix , Animais , Ecologia , Dinâmica Populacional , Estações do Ano
5.
Ying Yong Sheng Tai Xue Bao ; 31(1): 1-8, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957374

RESUMO

Endangered plant species are an important part of global biodiversity. To understand the competition patterns and mechanisms of endangered tree species from plant growth forms in the middle subtropical forest ecosystems, we examined the differences in intra- and inter-specific competitions between Toona ciliate var. pubescens (an intolerant of shade, deciduous species) and Taxus chinensis var. mairei (a tolerant of shade, evergreen species) in the Jiulingshan National Nature Reserve, Jiangxi Province. The results showed that intra-specific competition was dominant in the T. ciliate var. pubescens population, accounting for 66.4% of the total competition intensity. In contrary, the competitive intensity of T. chinensis var. mairei was dominated by the inter-specific competition, which accounted for 68.7% of the total competition intensity. The intra- and inter-specific competition intensity of both species decreased gradually with increasing tree diameter, indicating that competitive pressure was prevalent in small trees. T. ciliate var. pubescens was mainly affected by self-thinning due to intra-specific competition, whereas T. chinensis var. mairei was dominated by alien-thinning due to inter-specific competition. The small individuals of both species could develop into mature stage only after experiencing intense competitive selection during stand regeneration. Considering the substantial difference in the sources of competition pressures, different biodiversity conservation measures should be taken for the two endangered species with contrasting growth forms in the middle subtropical regions.


Assuntos
Taxus , Animais , China , Ecologia , Ecossistema , Espécies em Perigo de Extinção
6.
Ying Yong Sheng Tai Xue Bao ; 31(1): 208-218, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957398

RESUMO

The rational delimitation of urban development boundary plays an important role in guiding the orderly growth of urban space and ensure proper environment health of urban space. In this study, we evaluated the ecological sensitivity of Nanchang City from four aspects (soil erosion, habitat, geological disaster and water resource) and simulated urban expansion in 2020 based on CA-Markov and land use data in 2000, 2010 and 2015. Spatial decision-making analysis of the two aspects was carried out in combination to the future development of the study area. We proposed a new method of delimitating urban development boundary integrating environmental protection and urban development through the dynamic coordination of both aspects. The results showed that ecological sensitivity of Nanchang City was moderate. The scale of urban construction land based on CA Markov simulation was 1239.67 km2, which slightly exceeded the planned construction land target (1201.65 km2). When the dynamic adjustment was done by superimposing the ecological sensitivity evaluation results with the expansion simulation results, the adjusted construction land scale of Nanchang City was 1193.15 km2, which met the planned requirement. Consideration of the coordination of protection and development could not only protect the ecological space, but also help to guide the orderly growth of urban space and ensure the healthy development of urban space, and thus was an important way to achieve a win-win situation between rational urban development and ecological protection.


Assuntos
Ecologia , Reforma Urbana , China , Cidades , Conservação dos Recursos Naturais , Ecossistema
7.
Ying Yong Sheng Tai Xue Bao ; 31(1): 230-238, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957400

RESUMO

Xiamen is one of China's five major special economic zones and is the core city of Haixi Economic Zone, with a high level of urbanization. Monitoring and driving force analysis of impervious surfaces can increase our understanding of urbanization process and have important significance for urban landscape pattern research and urban ecological environment construction. We used the Landsat remote sensing image data from 1978 to 2018 to reveal the temporal and spatial variation characteristics of the impervious surface landscape in Xiamen in the past 40 years, using the full-restricted least squares method, landscape pattern analysis, slope gradient analysis and correlation analysis. We further analyzed its relationship with social and economic factors. The results showed that, during 1978-2018, the impervious surface of Xiamen increased by 348.96 km2, with a mean annual increase of 8.72 km2. The impervious surface dynamics reached a maximum of 9.0% in 2005-2010. More than 86.6% of the impervious surface of Xiamen was distributed within 6° of slope, with a tendency to expand to a greater slope in 2010-2018. With the increases of slope, the proportion of impervious surface decreased, the density of plaque decreased with the shape tending to be regular and continuous, the degree of fragmentation of the impervious surface increased. The increases of impervious surface in Xiamen was significantly related to the regional economic aggregate and population. In the study period, the spatial pattern of impervious surface in Xiamen significantly altered. In the future urban planning process, the extent and speed of impervious surface expansion should be coordinated to avoid ecological problems caused by excessive impervious surface to meet the need for sustainable development of Xiamen.


Assuntos
Planejamento de Cidades , Urbanização , China , Cidades , Ecologia
8.
Ying Yong Sheng Tai Xue Bao ; 31(1): 239-248, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957401

RESUMO

With Tongxin, Xiji, and Longde counties in the mountainous area of southern Ningxia as the research area, we used extended-exergy analysis (EEA) to compare their ecological efficiency driving mechanism in 2008-2017 to explore the causes of their variation in ecological degradation. The results showed that the overall difference of ecological efficiency in the three counties was significant during the study period. The ecological efficiency of Tongxin was low, with large inter-annual variation. The ecological efficiency of Xiji was stable, and the overall efficiency of Longde was the highest. The difference of exergy scale was small among the three counties. The exergy proportion in the economic sectors was not coordinated, which were dominated by agricultural and residential sectors. The economic sectors presented significant capital-pull-type and labor-intensive characteristics, indicating the driving force for ecological degradation mainly came from agricultural production and residents' lives in underdeveloped regions. The system's internal exergy conversion rate and the external energy exchange rate of the three counties were extremely low, constituting a simple network circulation path with high input, low storage, low opening and low conversion, which weakened the endogenous development of social economic subsystem and threatened the fragile ecosystem.


Assuntos
Ecologia , Ecossistema , Agricultura , China , Eficiência
9.
Ying Yong Sheng Tai Xue Bao ; 31(1): 293-300, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957407

RESUMO

It is important to reveal the interspecific association and correlation of main species for deep understanding of fish community structure and function. Based on data collected from the bottom trawl surveys from 2013 to 2017 in the Haizhou Bay and the adjacent waters, we analyzed interspecific association of main species using Chi-square test, Jaccard index, and Spearman rank correlation coefficient. There were consistent results from χ2-test, Jaccard index, and Spearman's rank correlation analysis. The proportion of positively correlated species pairs was high in different years, whereas the number of significant or extremely significant species pairs was low. There were 9, 6, 7, 1, 0 significant or extremely significant species pairs over different years based on Jaccard index. There were 12, 20, 13, 5, 6 significant or extremely significant species pairs over different years based on Spearman's rank correlation coefficient. While there were inter-annual changes in related species pairs, the relationship between significant species pairs was relatively stable, indicating a relatively stable interspecific association in the main fish communities. The species within the same ecological type could replace each other in the niche, which have adapted to environmental changes in Haizhou Bay and its adjacent waters.


Assuntos
Baías , Peixes , Animais , Ecologia , Estações do Ano
10.
Ying Yong Sheng Tai Xue Bao ; 31(1): 340-348, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957413

RESUMO

The relationship between biodiversity and ecosystem services is one of the hot topics in ecological research. The ways that the relationship is applied to the development of ecosystem management and policy have gradually gained attention after the Millennium Ecosystem Services Assessment in 2005. However, applying theoretical understanding of the relationship into practical management still faces challenges. Examining recent progresses may help to guide practices and po-licies. We summarized recent progress in researches on the relationship between biodiversity and ecosystem services in terms of the impacts of biodiversity on single ecosystem service, ecosystem multifunctionality and trade-offs of ecosystem services, as well as how environmental changes affected these relationships. Moreover, we outlined the application of these relationships in nature reserve management, forest management, degraded ecosystem restoration, and agro-ecosystem improvement. We further analyzed the shortcomings in relationship studies and then emphasized that future research and practice trends are the interaction of different biodiversity components and multiple trophic levels on ecosystem services, the coupling effects of environmental changes on the relationships, and practical approaches to biodiversity for improving ecosystem services.


Assuntos
Biodiversidade , Ecossistema , Conservação dos Recursos Naturais , Ecologia , Florestas
11.
J Environ Manage ; 258: 110048, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929076

RESUMO

This study put forward an evaluation index system for measuring forest ecological security index (FESI). Taking the 1086 counties located in the Yangtze River Economic Belt as a case study, we investigated the change and its spatial pattern of FESI, as well as the determining indicators (both natural and socio-economic), with the support of Arcmap and GeoDA software. The average FESI value of the study counties in 2010 and 2015 was found to be 0.4226 and 0.4990, increased by 18.08%. Spatially, an evident spatial gradient change was identified, with FESI values in the upstream areas of the Yangtze River being higher than those in midstream areas, and the values of midstream areas in turn being higher than those in downstream areas. The eight tributary basins within the economic belt witnessed significantly different FESI values. Based on the results of this evaluation of FESI and its sub-evaluation indexes, we identified 46.04% of the total counties as constituting "problem areas". These problem areas were mainly concentrated in Shanghai, Jiangsu and Anhui provinces, followed by counties around Dongting Lake, Poyang Lake and in Sichuan province. A regression analysis was conducted in order to identify the determining indicators behind forest ecological security, with results indicating that the ratio of secondary industry, the urbanization rate, the per capita financial institution loan balance, accumulated temperature and wind speed all negatively impacted on FESI values, while population structure, soil organic matter and rainfall were revealed to play a positive role; all of these indicators were highly significant. Given these findings, we also set out a series of policy measures intended to promote the sustainable forest development of the study region. These include the vigorous development of tertiary industry and moves to reduce the proportion of the secondary industry in the national economy, the development of a circular economy, slowing the pace of urbanization, and continued increases in forestry investment in central cities - particularly in problem areas.


Assuntos
Ecologia , Rios , China , Florestas , Urbanização
12.
Glob Chang Biol ; 26(1): 119-188, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891233

RESUMO

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.


Assuntos
Acesso à Informação , Ecossistema , Biodiversidade , Ecologia , Plantas
13.
J Environ Manage ; 256: 109894, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31989973

RESUMO

Despite the wide variety of variables commonly employed to measure the success of rehabilitation, the assessment and subsequent definition of indicators of environmental rehabilitation status are not simple tasks. The main challenges are comparing rehabilitated sites with target ecosystems as well as integrating individual environmental and eventually collinear variables into a single tractable measure for the state of a system before effective indicators that track rehabilitation may be modeled. Furthermore, a consensus is lacking regarding which and how many variables need to be surveyed for a reliable estimation of rehabilitation status. Here, we propose a multivariate ordination to integrate variables related to ecological processes, vegetation structure, and community diversity into a single estimation of rehabilitation status. As a case, we employed a curated set of 32 environmental variables retrieved from nonrevegetated, rehabilitating and reference sites associated with iron ore mines from the Urucum Massif, Mato Grosso do Sul, Brazil. By integrating this set of environmental variables into a single estimation of rehabilitation status, the proposed multivariate approach is straightforward and able to adequately address collinearity among variables. The proposed methodology allows for the identification of biases towards single variables, surveys or analyses, which is necessary to rank environmental variables regarding their importance to the assessment. Furthermore, we show that bootstrapping permitted the detection of the minimum number of environmental variables necessary to achieve reliable estimations of the rehabilitation status. Finally, we show that the proposed variable integration enables the definition of case-specific environmental indicators for more rapid assessments of mineland rehabilitation. Thus, the proposed multivariate ordination represents a powerful tool to facilitate the diagnosis of rehabilitating sites worldwide provided that sufficient environmental variables related to ecological processes, diversity and vegetation structure are gathered from nonrehabilitated, rehabilitating and reference study sites. By identifying deviations from predicted rehabilitation trajectories and providing assessments for environmental agencies, this proposed multivariate ordination increases the effectiveness of (mineland) rehabilitation.


Assuntos
Ecologia , Ecossistema , Brasil , Emprego , Monitoramento Ambiental , Mineração
14.
Lancet ; 395(10220): e14, 2020 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-31982076
15.
Nat Commun ; 11(1): 545, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992718

RESUMO

Severe droughts have the potential to reduce forest productivity and trigger tree mortality. Most trees face several drought events during their life and therefore resilience to dry conditions may be crucial to long-term survival. We assessed how growth resilience to severe droughts, including its components resistance and recovery, is related to the ability to survive future droughts by using a tree-ring database of surviving and now-dead trees from 118 sites (22 species, >3,500 trees). We found that, across the variety of regions and species sampled, trees that died during water shortages were less resilient to previous non-lethal droughts, relative to coexisting surviving trees of the same species. In angiosperms, drought-related mortality risk is associated with lower resistance (low capacity to reduce impact of the initial drought), while it is related to reduced recovery (low capacity to attain pre-drought growth rates) in gymnosperms. The different resilience strategies in these two taxonomic groups open new avenues to improve our understanding and prediction of drought-induced mortality.


Assuntos
Secas , Árvores/crescimento & desenvolvimento , Adaptação Fisiológica , Mudança Climática , Cycadopsida/crescimento & desenvolvimento , Ecologia , Florestas , Magnoliopsida/crescimento & desenvolvimento , Mortalidade , Solo/química , Especificidade da Espécie , Estresse Fisiológico , Análise de Sobrevida , Árvores/classificação , Água
16.
Environ Monit Assess ; 192(2): 83, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900674

RESUMO

In ecological risk assessment, sum-of-toxic-unit approaches based on measured water quality factors such as trace metals are used to infer ecological impacts in the environment. However, it is uncertain whether the use of such approaches yields accurate risk predictions. To address this issue, we investigated and compared (1) water quality, including trace metals, and (2) benthic macroinvertebrate communities in a northern Japanese river receiving treated discharge from an abandoned mine and in a nearby reference river. As a sum-of-toxic-unit approach, we employed a cumulative criterion unit (CCU), namely, the sum of the ratios of the dissolved concentrations of a metal (Cu, Zn, Cd, or Pb) divided by the US Environmental Protection Agency hardness-adjusted environmental water quality criterion for that metal. Compared with the reference sites, at the metal-contaminated sites, the richness, abundance, and structure of macroinvertebrate communities were little affected, with CCUs of 1.7 to 7.4, suggesting that CCU values exceeding 1 do not always indicate marked adverse impacts on these metrics. Further study is still required to derive a more compelling conclusion on the generally applicable relationships between CCUs and ecological impacts on river invertebrates. This would lead to better ecological risk assessments based on sum-of-toxic-unit approaches.


Assuntos
Biodiversidade , Monitoramento Ambiental , Invertebrados , Poluentes Químicos da Água/análise , Animais , Ecologia , Japão , Metais/toxicidade , Metais Pesados/análise , Rios/química , Qualidade da Água
17.
Nat Commun ; 11(1): 576, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996690

RESUMO

Urbanisation is an important global driver of biodiversity change, negatively impacting some species groups whilst providing opportunities for others. Yet its impact on ecosystem services is poorly investigated. Here, using a replicated experimental design, we test how Central European cities impact flying insects and the ecosystem service of pollination. City sites have lower insect species richness, particularly of Diptera and Lepidoptera, than neighbouring rural sites. In contrast, Hymenoptera, especially bees, show higher species richness and flower visitation rates in cities, where our experimentally derived measure of pollination is correspondingly higher. As well as revealing facets of biodiversity (e.g. phylogenetic diversity) that correlate well with pollination, we also find that ecotones in insect-friendly green cover surrounding both urban and rural sites boost pollination. Appropriately managed cities could enhance the conservation of Hymenoptera and thereby act as hotspots for pollination services that bees provide to wild flowers and crops grown in urban settings.


Assuntos
Abelhas/fisiologia , Ecologia , Insetos/fisiologia , Polinização , Urbanização , Animais , Abelhas/classificação , Biodiversidade , Cidades , Dípteros , Ecossistema , Flores , Alemanha , Himenópteros , Insetos/classificação , Lepidópteros , Filogenia
18.
BMC Ecol ; 20(1): 3, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31914976

RESUMO

BACKGROUND: Accurate network models of species interaction could be used to predict population dynamics and be applied to manage real world ecosystems. Most relevant models are nonlinear, however, and data available from real world ecosystems are too noisy and sparsely sampled for common inference approaches. Here we improved the inference of generalized Lotka-Volterra (gLV) ecological networks by using a new optimization algorithm to constrain parameter signs with prior knowledge and a perturbation-based ensemble method. RESULTS: We applied the new inference to long-term species abundance data from the freshwater fish community in the Illinois River, United States. We constructed an ensemble of 668 gLV models that explained 79% of the data on average. The models indicated (at a 70% level of confidence) a strong positive interaction from emerald shiner (Notropis atherinoides) to channel catfish (Ictalurus punctatus), which we could validate using data from a nearby observation site, and predicted that the relative abundances of most fish species will continue to fluctuate temporally and concordantly in the near future. The network shows that the invasive silver carp (Hypophthalmichthys molitrix) has much stronger impacts on native predators than on prey, supporting the notion that the invader perturbs the native food chain by replacing the diets of predators. CONCLUSIONS: Ensemble approaches constrained by prior knowledge can improve inference and produce networks from noisy and sparsely sampled time series data to fill knowledge gaps on real world ecosystems. Such network models could aid efforts to conserve ecosystems such as the Illinois River, which is threatened by the invasion of the silver carp.


Assuntos
Ecossistema , Rios , Animais , Ecologia , Cadeia Alimentar , Dinâmica Populacional , Estados Unidos
19.
Ecol Lett ; 23(2): 370-380, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31773839

RESUMO

Plant spectral diversity - how plants differentially interact with solar radiation - is an integrator of plant chemical, structural, and taxonomic diversity that can be remotely sensed. We propose to measure spectral diversity as spectral variance, which allows the partitioning of the spectral diversity of a region, called spectral gamma (γ) diversity, into additive alpha (α; within communities) and beta (ß; among communities) components. Our method calculates the contributions of individual bands or spectral features to spectral γ-, ß-, and α-diversity, as well as the contributions of individual plant communities to spectral diversity. We present two case studies illustrating how our approach can identify 'hotspots' of spectral α-diversity within a region, and discover spectrally unique areas that contribute strongly to ß-diversity. Partitioning spectral diversity and mapping its spatial components has many applications for conservation since high local diversity and distinctiveness in composition are two key criteria used to determine the ecological value of ecosystems.


Assuntos
Biodiversidade , Ecossistema , Ecologia , Plantas
20.
Ecol Lett ; 23(2): 293-304, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31775182

RESUMO

Social information networks have the potential to shape the spatial structure of ecological communities by promoting the formation of mixed-species groups. However, what actually drives social affinity between species in the wild will depend on the characteristics of the species available to group. Here we first present an agent-based model that predicts trait-related survival benefits from mixed-species group formation in a multi-species community and we then test the model predictions in a community-wide field study of African savannah herbivores using multi-layered network analysis. We reveal benefits from information transfer about predators as a key determinant of mixed-species group formation, and that dilution benefits alone are not enough to explain patterns in interspecific sociality. The findings highlight the limitations of classical ecological approaches focusing only on direct trophic interactions when analysing community structure and suggest that declines in species occupying central social network positions, such as key informants, can have significant repercussions throughout communities.


Assuntos
Ecologia , Herbivoria , Biota
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