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Andres Felipe Suárez-Castro;Orlando Acevedo-Charry;Luis Hernando Romero Jiménez;Elkin A. Noguera-Urbano;Fernando Ayerbe-Quiñones;Natalia Ocampo-Peñuela; 《Diversity & distributions》2024,30(10):e13917
Global species distribution maps tend to be limited to a reduced number of species or are too coarse to inform ecological research and conservation actions at local scales. We developed a workflow to generate species range and area of habitat (AOH) maps tailored to local contexts based on expert information, community science observations and an ecoregion approach. We also developed a workflow to increase transparency in range maps and map the areas of uncertainty at the species and community levels using community science data. 相似文献
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Aim The method used to generate hypotheses about species distributions, in addition to spatial scale, may affect the biodiversity patterns that are then observed. We compared the performance of range maps and MaxEnt species distribution models at different spatial resolutions by examining the degree of similarity between predicted species richness and composition against observed values from well‐surveyed cells (WSCs). Location Mexico. Methods We estimated amphibian richness distributions at five spatial resolutions (from 0.083° to 2°) by overlaying 370 individual range maps or MaxEnt predictions, comparing the similarity of the spatial patterns and correlating predicted values with the observed values for WSCs. Additionally, we looked at species composition and assessed commission and omission errors associated with each method. Results MaxEnt predictions reveal greater geographic differences in richness between species rich and species poor regions than the range maps did at the five resolutions assessed. Correlations between species richness values estimated by either of the two procedures and the observed values from the WSCs increased with decreasing resolution. The slopes of the regressions between the predicted and observed values indicate that MaxEnt overpredicts observed species richness at all of the resolutions used, while range maps underpredict them, except at the finest resolution. Prediction errors did not vary significantly between methods at any resolution and tended to decrease with decreasing resolution. The accuracy of both procedures was clearly different when commission and omission errors were examined separately. Main conclusions Despite the congruent increase in the geographic richness patterns obtained from both procedures as resolution decreases, the maps created with these methods cannot be used interchangeably because of notable differences in the species compositions they report. 相似文献
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Aim To develop an approach for assessing the spatial scale of centres of endemism among species level data.
Location Australia.
Methods Endemism is inherently scale dependent. Therefore, the Corrected Weighted Endemism (CWE) index used by Crisp et al. [ J. Biogeogr. (2001)28:183] is extended to account for species samples in local neighbourhoods as a Spatial CWE index. This then allows an analysis of how the degree of endemism of a location (cell) changes with spatial scale. The quality of the Spatial CWE index results are assessed using three spatial randomizations at the species level with and without preserving species richness and distributional patterns. We show that CWE is equivalent to beta diversity and predict that it should show high rates of change around centres of endemism.
Results Similar patterns to those found by Crisp et al. using a data set of vascular flora from Australia are retrieved, but the extent to which they are scale dependent is more easily identified. For example, the Central Australian centre discounted by Crisp et al. is identified when a three-cell radius neighbourhood is used. However, the level of endemism in this centre is no greater than in the margins of many of the coastal centres of endemism. Most of the identified centres of endemism are better than random at all scales and are increasingly so as the spatial scale increases. As predicted, the highest rate of change in Spatial CWE (beta diversity) is most often between zero- and one-cell radius neighbours in most centres of endemism.
Main conclusions The explicit incorporation of geographical space in analyses allows for a greater understanding of the scale-dependence of phenomena, in this case endemism and beta diversity. 相似文献
Location Australia.
Methods Endemism is inherently scale dependent. Therefore, the Corrected Weighted Endemism (CWE) index used by Crisp et al. [ J. Biogeogr. (2001)28:183] is extended to account for species samples in local neighbourhoods as a Spatial CWE index. This then allows an analysis of how the degree of endemism of a location (cell) changes with spatial scale. The quality of the Spatial CWE index results are assessed using three spatial randomizations at the species level with and without preserving species richness and distributional patterns. We show that CWE is equivalent to beta diversity and predict that it should show high rates of change around centres of endemism.
Results Similar patterns to those found by Crisp et al. using a data set of vascular flora from Australia are retrieved, but the extent to which they are scale dependent is more easily identified. For example, the Central Australian centre discounted by Crisp et al. is identified when a three-cell radius neighbourhood is used. However, the level of endemism in this centre is no greater than in the margins of many of the coastal centres of endemism. Most of the identified centres of endemism are better than random at all scales and are increasingly so as the spatial scale increases. As predicted, the highest rate of change in Spatial CWE (beta diversity) is most often between zero- and one-cell radius neighbours in most centres of endemism.
Main conclusions The explicit incorporation of geographical space in analyses allows for a greater understanding of the scale-dependence of phenomena, in this case endemism and beta diversity. 相似文献
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中国北方典型草地物种丰富度与生产力的关系 总被引：13，自引：0，他引：13
利用2002–2004年内蒙古和甘肃南部几种典型草地的实测资料,研究了不同尺度物种丰富度与生产力的关系,并初步探讨了其形成机制。结果显示,温带草地的物种丰富度随生产力的增加而增加,但受空间尺度影响。在群落尺度(同一群落),在7种样方数大于15的群落中,仅沙生针茅(Stipaglareosa)群落物种丰富度与生产力呈现单峰型关系,其余均呈现线性正相关关系;在植被类型尺度,物种丰富度–生产力之间表现为显著的正相关关系;在研究区尺度,物种丰富度随生产力的增加而显著增加。研究还表明,研究区群落生产力的变化范围为13–368g·m–2·yr–1,物种丰富度为4–35种;生产力从高到低的顺序为:高寒草甸>草甸草原>典型草原>荒漠草原。 相似文献
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Dan Cog?lniceanu Laurentiu Rozylowicz Paul Székely Ciprian Samoil? Florina St?nescu Marian Tudor Diana Székely Ruben Iosif 《ZooKeys》2013,(341):49-76
The reptile fauna of Romania comprises 23 species, out of which 12 species reach here the limit of their geographic range. We compiled and updated a national database of the reptile species occurrences from a variety of sources including our own field surveys, personal communication from specialists, museum collections and the scientific literature. The occurrence records were georeferenced and stored in a geodatabase for additional analysis of their spatial patterns. The spatial analysis revealed a biased sampling effort concentrated in various protected areas, and deficient in the vast agricultural areas of the southern part of Romania. The patterns of species richness showed a higher number of species in the warmer and drier regions, and a relatively low number of species in the rest of the country. Our database provides a starting point for further analyses, and represents a reliable tool for drafting conservation plans. 相似文献
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Dan Cog?lniceanu Paul Székely Ciprian Samoil? Iosif Ruben Marian Tudor Rodica Pl?ia?u Florina St?nescu Lauren?iu Rozylowicz 《ZooKeys》2013,(296):35-57
Nineteen species of amphibians inhabit Romania, 9 of which reach their range limit on this territory. Based on published occurrence reports, museum collections and our own data we compiled a national database of amphibian occurrences. We georeferenced 26779 amphibian species occurrences, and performed an analysis of their spatial patterns, checking for hotspots and patterns of species richness. The results of spatial statistic analyses supported the idea of a biased sampling for Romania, with clear hotspots of increased sampling efforts. The sampling effort is biased towards species with high detectability, protected areas, and large cities. Future sampling efforts should be focused mostly on species with a high rarity score in order to accurately map their range. Our results are an important step in achieving the long-term goals of increasing the efficiency of conservation efforts and evaluating the species range shifts under climate change scenarios. 相似文献
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Gabriela Franzoi Dri;Nilton Carlos Cáceres;Franchesco Della-Flora;Cristian Sales Dambros; 《Oikos》2022,2022(8):e09115
Many animal species participate in interspecific groups which can provide benefits such as better detection of predator presence, but may also lead to costs such as interspecific competition. In interspecific groups, species with particular functional traits should be aggregated in a way that maximizes the benefits and minimizes the costs of these interactions. Further, the balance between costs and benefits depends on the resource availability and the spatial scale in which species interact. We aim to determine how species traits are distributed within and among interspecific groups and how intrinsic (group size) and extrinsic (environmental conditions) factors relate to aggregation patterns. We surveyed 192 bird species distributed in 355 mixed-species bird flocks along an environmental gradient in southwest Brazil and analyzed data at both scales of individual flocks (n = 355) and sites (n = 29). We used mixed-effect and multiple regression models to test if the functional richness of coexisting species changes with increasing group size and in response to environmental covariates that may influence the selection of specific traits. Using a null model approach, we inferred the differences between observed and simulated associations (random expectations). We found that groups with more than 20 species have greater diet variation (i.e. more omnivores) and are more similar in body mass than expected randomly. Indeed, larger groups consume more resources, increasing competitive dynamics and decreasing facilitation among species. Thus such groups should take advantage of a more profitable trait variation among co-occurring species. Our results suggest that the distribution of species in close associations is determined mostly by ecological processes occurring at local scales (i.e. not dependent on regional spatial context). Additionally, larger groups maximize foraging trait variation (diet diversity) and minimize predator scape variation (similar body mass) potentially increasing the benefits of the aggregation. 相似文献
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Pablo V. C. Mathias† Cláudio V. Mendonça† Thiago F. L. V. B. Rangel‡ José A. F. Diniz-Filho‡§ 《Global Ecology and Biogeography》2004,13(3):193-198
A criticism of macroecological studies has been their extensive use of secondary data sources. In this note we evaluate how different data sources affect macroecological patterns for the parrots of South America. We mapped extents of parrot occurrence based on four sources of range maps. We compared basic statistics for geographical range size distribution (mean, variance and skew) and calculated correlations between geographical range size estimates and grid cell species richness estimates. Finally, results from multiple regression analyses of species richness against six environmental variables were also compared. We found that patterns were very robust to the data source, with only relatively slight quantitative differences. Our results reinforce the notion that patterns emerging from macroecological analyses are robust to variations in data sources and cannot be merely artefacts resulting from low data quality, notably poorly defined mapping and conflicting taxonomy. 相似文献
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Jonathan M. Chase Brian J. McGill Patrick L. Thompson Laura H. Anto Amanda E. Bates Shane A. Blowes Maria Dornelas Andrew Gonzalez Anne E. Magurran Sarah R. Supp Marten Winter Anne D. Bjorkman Helge Bruelheide Jarrett E. K. Byrnes Juliano Sarmento Cabral Robin Elahi Catalina Gomez Hector M. Guzman Forest Isbell Isla H. Myers‐Smith Holly P. Jones Jes Hines Mark Vellend Conor Waldock Mary O'Connor 《Oikos》2019,128(8):1079-1091
Humans have elevated global extinction rates and thus lowered global scale species richness. However, there is no a priori reason to expect that losses of global species richness should always, or even often, trickle down to losses of species richness at regional and local scales, even though this relationship is often assumed. Here, we show that scale can modulate our estimates of species richness change through time in the face of anthropogenic pressures, but not in a unidirectional way. Instead, the magnitude of species richness change through time can increase, decrease, reverse, or be unimodal across spatial scales. Using several case studies, we show different forms of scale‐dependent richness change through time in the face of anthropogenic pressures. For example, Central American corals show a homogenization pattern, where small scale richness is largely unchanged through time, while larger scale richness change is highly negative. Alternatively, birds in North America showed a differentiation effect, where species richness was again largely unchanged through time at small scales, but was more positive at larger scales. Finally, we collated data from a heterogeneous set of studies of different taxa measured through time from sites ranging from small plots to entire continents, and found highly variable patterns that nevertheless imply complex scale‐dependence in several taxa. In summary, understanding how biodiversity is changing in the Anthropocene requires an explicit recognition of the influence of spatial scale, and we conclude with some recommendations for how to better incorporate scale into our estimates of change. 相似文献
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Switzerland's governmental ‘Biodiversity Monitoring’ program is designed to produce factual information on the dynamics of biodiversity within the country for governmental agencies, politicians, and the general public. Monitoring a complex issue like biodiversity in order to give relevant and accurate messages to the general public and politicians within a politically relevant timescale and at moderate cost means focusing on few elements. Because relevant human impacts on biodiversity operate differently at different spatial scales, we need at least three different indicators to observe changes over time in local (‘within‐habitat’), landscape (‘habitat‐mosaic’), and macro‐scale (‘regional’) diversity. To keep things as simple as possible, we use species richness as an indicator for all three levels of diversity, just defining three different spatial scales (10 m2, 1 km2, regions, respectively). Each indicator is based on a number of taxonomic groups which have been selected mainly on the basis of costs and the availability of appropriate methods. 相似文献
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Victoria Veach Enrico Di Minin Federico M. Pouzols Atte Moilanen 《Diversity & distributions》2017,23(7):715-726
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Aim Species richness patterns along elevational gradients have been documented extensively. Yet, the implications of differences in how the data are compiled are seldom explored. We investigate the effect of grain size on the richness–elevation relationship. Grain size varies among the principal methods used to collect or aggregate species occurrences: localized sites, elevational ‘bins’ and interpolation of species ranges. Assumptions of sampling and species distributions also vary among these methods. Methodology can influence the pattern that is perceived and comparability of results. We compare patterns from all three methods explicitly using the same suite of observations, based on museum records and field surveys of non‐flying small mammals. Our assessment is enhanced by comparing patterns resulting from each method for each of six adjacent mountain ranges. Location Utah, North America. Methods We document elevational species richness patterns using generalized linear models (GLMs), comparing the general shape of the trend as well as curvature, location and magnitude of peak richness across methods, both within and among gradients. We also introduce a new procedure to test for richness peaks using site‐based occurrences. Results We find a general congruence of the richness–elevation relationship, depicting a hump‐shaped pattern with a second‐order polynomial GLM showing a significant fit to nearly all gradient‐methodology combinations. However, underlying characteristics of the trend may vary with grain size. As grain size coarsens, maximum species richness increases and elevation of the mode slightly decreases. Results for curvature vary, but degree of curvature tends to increase as grain size coarsens. The richness–elevation patterns are independent of sampling effects. Main conclusions The perceived elevational diversity pattern for small mammals along these mountain ranges is not scale‐dependent. Differences in how the data are compiled are not reflected in major differences in patterns, even when local samples are neither uniformly spaced nor sampled with the same intensity. This result lends confidence to the assertion that patterns documented in similar studies with different methodologies and for which sampling is sufficiently comprehensive are good indicators of diversity. However, consistency of results from more than one compilation method may help to address issues of scale‐dependence, more so when these comparisons are made explicit. 相似文献
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Ma Wenhong 《Frontiers of Biology in China》2007,2(3):318-323
The relationship between plant species richness and primary productivity has long been a central topic in biodiversity research.
In this paper, we examine the relationship between species richness and productivity in four typical grasslands of Northern
China at different spatial scales. At the community scale, a positive correlation was found for six of seven communities.
A unimodal pattern was found only for one community (Stipa glareosa community), while at a large scale (vegetation type or landscape/region), the relationship was also found significantly positive.
Species richness ranged from 4 to 35 species, and community aboveground productivity from 13 to 368 g·m−2·a−1. The highest species richness and aboveground productivity were found in alpine meadow, followed by meadow steppe, typical
steppe and desert steppe.
Translated from Biodiversity Science, 2006, 14(1): 21–28 [译自: 生物多样性] 相似文献
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Abstract: Little quantitative information exists about the survey effort necessary to inventory temperate bat species assemblages. We used a bootstrap resampling algorithm to estimate the number of mist net surveys required to capture individuals from 9 species at both study area and site levels using data collected in a forested watershed in northwestern California, USA, during 1996–2000. The mean number of simulated surveys required to capture individual species varied with species' rarity and ranged from 1.5 to 44.9. We retrospectively evaluated strategies to reduce required survey effort by subsampling data from 1996 to 1998 and tested the strategies in the field during 1999 and 2000. Using data from 1996 to 1998, the mean number of simulated surveys required to capture 8 out of 9 species was 26.3, but a 95% probability of capture required >61 surveys. Inventory efficiency, defined as the cumulative proportion of species detected per survey effort, improved for both the study area and individual sites by conducting surveys later in summer. We realized further improvements in study area inventory efficiency by focusing on productive sites. We found that 3 surveys conducted between 1 July and 10 September at each of 4 productive sites in this 10-km2 study area resulted in the capture of 8 species annually. Quantitative estimation of the survey effort required to assess bat species occurrence improves the ability to plan and execute reliable, efficient inventories. Results from our study should be useful for planning inventories in nearby geographical areas and similar habitat types; further, the analytical methods we used to assess effort are broadly applicable to other survey methods and taxa. 相似文献