Methods and uncertainties in bioclimatic envelope modelling under climate change

Progress in Physical Geography Earth and Environment, Journal Year: 2006, Volume and Issue: 30(6), P. 751 - 777

Published: Dec. 1, 2006

Potential impacts of projected climate change on biodiversity are often assessed using single-species bioclimatic ‘envelope’models. Such models a special case species distribution in which the current geographical is related to climatic variables so enable projections distributions under future scenarios. This work reviews number critical methodological issues that may lead uncertainty predictions from modelling. Particular attention paid recent developments modelling address some these as well topics where more progress needs be made. Developing and applying informative way requires good understanding wide range methodologies, including choice technique, model validation, collinearity, autocorrelation, biased sampling explanatory variables, scaling non-climatic factors. A key challenge for research integrating factors such land cover, direct CO 2 effects, biotic interactions dispersal mechanisms into species-climate models. We conclude that, although envelope have important advantages, they need applied only when users thorough their limitations uncertainties.

Language: Английский

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Soil pH drives the spatial distribution of bacterial communities along elevation on Changbai Mountain

Soil Biology and Biochemistry, Journal Year: 2012, Volume and Issue: 57, P. 204 - 211

Published: Aug. 17, 2012

Language: Английский

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Microbes on mountainsides: Contrasting elevational patterns of bacterial and plant diversity

Proceedings of the National Academy of Sciences, Journal Year: 2008, Volume and Issue: 105(supplement_1), P. 11505 - 11511

Published: Aug. 12, 2008

The study of elevational diversity gradients dates back to the foundation biogeography. Although patterns plant and animal have been studied for centuries, such not reported microorganisms remain poorly understood. Here, in an effort assess generality patterns, we examined soil bacterial along elevation gradient. To gain insight into forces that structure these adopted a multifaceted approach incorporate information about structure, diversity, spatial turnover montane communities phylogenetic context. We found observed were fundamentally different. While taxon richness decreased monotonically from lowest highest elevations, plants followed unimodal pattern, with peak at mid-elevations. At all elevations had tendency be phylogenetically clustered, containing closely related taxa. In contrast, did exhibit uniform across gradient: they became more overdispersed increasing elevation, distantly Finally, metric beta-diversity showed lineages randomly distributed, but rather exhibited significant gradient, whereas signal. Quantifying influence sample scale intertaxonomic comparisons remains challenge. Nevertheless, our findings suggest structuring microorganism macroorganism differ.

Language: Английский

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Spatial species‐richness gradients across scales: a meta‐analysis

Journal of Biogeography, Journal Year: 2008, Volume and Issue: 36(1), P. 132 - 147

Published: Sept. 10, 2008

Abstract Aim We surveyed the empirical literature to determine how well six diversity hypotheses account for spatial patterns in species richness across varying scales of grain and extent. Location Worldwide. Methods identified 393 analyses (‘cases’) 297 publications meeting our criteria. These criteria included requirement that more than one hypothesis was tested its relationship with richness. grouped variables representing into following ‘correlate types’: climate/productivity, environmental heterogeneity, edaphics/nutrients, area, biotic interactions dispersal/history (colonization limitation or other historical evolutionary effect). For each case we determined ‘primary’ variable: most strongly correlated taxon defined ‘primacy’ as proportion cases which correlate type represented by primary variable, relative number times it studied. differences both primacy mean coefficient determination variable between categories five grouping variables: grain, extent, (animal vs. plant), habitat medium (land water) insularity (insular connected). Results Climate/productivity had highest overall primacy, heterogeneity lowest. Primacy climate/productivity much higher large‐grain large‐extent studies at smaller scales. It also on land water, connected systems insular ones. hypotheses, were less pronounced. Throughout, plants animals showed similar patterns. Coefficients differed little variables, strongest effects being low means smallest class edaphics/nutrients a water but vice versa systems. highlight areas data deficiency. Main conclusions Our results support notion climate productivity play an important role determining large scales, particularly non‐insular, terrestrial habitats. At extents sizes, different types correlates appears differ from null expectation. In analysis, is rarely best richness, this may reflect difficulty incorporating factors regression models, collinearity past current climates. findings are consistent view determines capacity However, influence evident probably because (1) small extent tend sample climatic range, (2) grains some influences vary mainly within sampling unit.

Language: Английский

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Disentangling the Drivers of β Diversity Along Latitudinal and Elevational Gradients

Science, Journal Year: 2011, Volume and Issue: 333(6050), P. 1755 - 1758

Published: Sept. 22, 2011

Understanding spatial variation in biodiversity along environmental gradients is a central theme ecology. Differences species compositional turnover among sites (β diversity) occurring are often used to infer the processes structuring communities. Here, we show that sampling alone predicts changes β diversity caused simply by sizes of pools. For example, forest inventories sampled latitudinal and elevational well-documented pattern higher tropics at low elevations. However, after correcting for pooled richness (γ diversity), these differences disappear. Therefore, there no need invoke mechanisms community assembly temperate versus tropical systems explain global-scale patterns diversity.

Language: Английский

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Species richness, hotspots, and the scale dependence of range maps in ecology and conservation

Proceedings of the National Academy of Sciences, Journal Year: 2007, Volume and Issue: 104(33), P. 13384 - 13389

Published: Aug. 9, 2007

Most studies examining continental-to-global patterns of species richness rely on the overlaying extent-of-occurrence range maps. Because a does not occur at all locations within its geographic range, range-map-derived data represent actual distributional only some relatively coarse and undefined resolution. With increasing availability high-resolution climate land-cover data, broad-scale are increasingly likely to estimate high resolutions. scale dependence most ecological phenomena, significant mismatch between presumed may arise. This affect conclusions regarding basic drivers diversity lead errors in identification hotspots. Here, we examine avian maps 834 bird conjunction with geographically extensive survey sets two continents determine spatial resolutions which range-map actually characterize occurrences richness. At less than 2° (≈200 km), overestimate area occupancy individual mischaracterize richness, resulting up two-thirds biodiversity hotspots being misidentified. The accuracy poses clear limitations analyses conservation assessments. We suggest that contain information is generally assumed provide guidance about appropriate their use.

Language: Английский

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Towards an integrated computational tool for spatial analysis in macroecology and biogeography

Global Ecology and Biogeography, Journal Year: 2006, Volume and Issue: 15(4), P. 321 - 327

Published: May 8, 2006

ABSTRACT Because most macroecological and biodiversity data are spatially autocorrelated, special tools for describing spatial structures dealing with hypothesis testing usually required. Unfortunately, of these methods have not been available in a single statistical package. Consequently, using is still challenge ecologists biogeographers. In this paper, we present sam (Spatial Analysis Macroecology), new, easy‐to‐use, freeware package analysis macroecology biogeography. Through an intuitive, fully graphical interface, allows the user to describe patterns variables provides explicit framework standard techniques regression correlation. Moran's I autocorrelation coefficient can be calculated based on range matrices relationships, original as well residuals models, which also include filtering components (obtained by trend surface or principal coordinates neighbour matrices). offers correcting number degrees freedom when calculating significance correlation coefficients. Explicit modelling several forms autoregression generalized least‐squares models available. We believe new tool will provide researchers basic resolve problems and, simultaneously, explore biogeographical data. Although program was designed primarily applications biogeography, 's useful all kinds pattern analysis. The freely at http://www.ecoevol.ufg.br/sam (permanent URL http://purl.oclc.org/sam/ ).

Language: Английский

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Community and Ecosystem Responses to Elevational Gradients: Processes, Mechanisms, and Insights for Global Change

Annual Review of Ecology Evolution and Systematics, Journal Year: 2013, Volume and Issue: 44(1), P. 261 - 280

Published: Nov. 23, 2013

Community structure and ecosystem processes often vary along elevational gradients. Their responses to elevation are commonly driven by changes in temperature, many community- ecosystem-level variables therefore frequently respond similarly across contrasting There also exceptions, sometimes because other factors such as precipitation can with elevation. Given this complexity, our capacity predict when why the same variable responds differently among disparate gradients is limited. Furthermore, there utility using for understanding community global climate change at much larger spatial temporal scales than possible through conventional ecological experiments. However, future studies that integrate gradient approaches experimental manipulations will provide powerful information improve predictions of impacts within ecosystems.

Language: Английский

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Elevational Gradients in Species Richness

Encyclopedia of Life Sciences, Journal Year: 2010, Volume and Issue: unknown

Published: Sept. 15, 2010

Abstract The abiotic and biotic gradients on mountains have enormous potential to improve our understanding of species distributions, richness patterns conservation. Here we describe how factors change with elevation, flora fauna respond these changes elevational been studied uncover drivers biodiversity. There are four main trends in richness: decreasing increasing plateaus across low elevations then or without a mid‐elevation peak unimodal pattern mid‐elevational peak. We discuss the history studies overview various hypotheses thought be important trends, including climatic, spatial, evolutionary factors. Key Concepts: Elevational exhibit complex variation conditions over short distances. Patterns follow common patterns: peaks, decreasing, low‐elevation peaks. vary between taxonomic groups. A combination water availability temperature is often found related patterns. No consistent support for importance area mid‐domain effects Support mechanisms underlying tends ecology group interest. valuable task disentangle causes behind broad‐scale biodiversity, quest understand threats biodiversity climatic change.

Language: Английский

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The imprint of the geographical, evolutionary and ecological context on species–area relationships

Ecology Letters, Journal Year: 2005, Volume and Issue: 9(2), P. 215 - 227

Published: Nov. 24, 2005

Abstract Species–area relationships (SAR) are fundamental in the understanding of biodiversity patterns and critical importance for predicting species extinction risk worldwide. Despite enormous attention given to SAR form many individual analyses, little attempt has been made synthesize these studies. We conducted a quantitative meta‐analysis 794 SAR, comprising wide span organisms, habitats locations. identified factors reflecting both pattern‐based dynamic approaches tested whether leave significant imprints on slope strength SAR. Our analysis revealed that significantly affected by variables characterizing sampling scheme, spatial scale, types organisms or involved. found steeper generated at lower latitudes larger organisms. varied between nested independent schemes major ecosystem types, but not generally terrestrial aquatic realm. Both fit were scale‐dependent. conclude dynamically regulating richness different scales strongly affect shape highlight important consequences this systematic variation ecological theory, conservation management predictions.

Language: Английский

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