scholarly journals Topography, energy and the global distribution of bird species richness

2007 ◽  
Vol 274 (1614) ◽  
pp. 1189-1197 ◽  
Author(s):  
Richard G Davies ◽  
C. David L Orme ◽  
David Storch ◽  
Valerie A Olson ◽  
Gavin H Thomas ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Bird Species ◽  
Geometric Constraints ◽  
Global Distribution ◽  
Current Evidence ◽  
Energy Availability ◽  
Relative Importance ◽  
Environmental Predictors ◽  
Predictor Models

A major goal of ecology is to determine the causes of the latitudinal gradient in global distribution of species richness. Current evidence points to either energy availability or habitat heterogeneity as the most likely environmental drivers in terrestrial systems, but their relative importance is controversial in the absence of analyses of global (rather than continental or regional) extent. Here we use data on the global distribution of extant continental and continental island bird species to test the explanatory power of energy availability and habitat heterogeneity while simultaneously addressing issues of spatial resolution, spatial autocorrelation, geometric constraints upon species' range dynamics, and the impact of human populations and historical glacial ice-cover. At the finest resolution (1°), topographical variability and temperature are identified as the most important global predictors of avian species richness in multi-predictor models. Topographical variability is most important in single-predictor models, followed by productive energy. Adjusting for null expectations based on geometric constraints on species richness improves overall model fit but has negligible impact on tests of environmental predictors. Conclusions concerning the relative importance of environmental predictors of species richness cannot be extrapolated from one biogeographic realm to others or the globe. Rather a global perspective confirms the primary importance of mountain ranges in high-energy areas.

scholarly journals Modelling avian biodiversity using raw, unclassified satellite imagery

2014 ◽  
Vol 369 (1643) ◽  
pp. 20130197 ◽  
Author(s):  
Véronique St-Louis ◽  
Anna M. Pidgeon ◽  
Tobias Kuemmerle ◽  
Ruth Sonnenschein ◽  
Volker C. Radeloff ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Bird Species ◽  
Image Texture ◽  
Spectral Mixture Analysis ◽  
Mixture Analysis ◽  
Bird Species Richness ◽  
Habitat Composition ◽  
Avian Biodiversity ◽  
Spectral Mixture

Applications of remote sensing for biodiversity conservation typically rely on image classifications that do not capture variability within coarse land cover classes. Here, we compare two measures derived from unclassified remotely sensed data, a measure of habitat heterogeneity and a measure of habitat composition, for explaining bird species richness and the spatial distribution of 10 species in a semi-arid landscape of New Mexico. We surveyed bird abundance from 1996 to 1998 at 42 plots located in the McGregor Range of Fort Bliss Army Reserve. Normalized Difference Vegetation Index values of two May 1997 Landsat scenes were the basis for among-pixel habitat heterogeneity (image texture), and we used the raw imagery to decompose each pixel into different habitat components (spectral mixture analysis). We used model averaging to relate measures of avian biodiversity to measures of image texture and spectral mixture analysis fractions. Measures of habitat heterogeneity, particularly angular second moment and standard deviation, provide higher explanatory power for bird species richness and the abundance of most species than measures of habitat composition. Using image texture, alone or in combination with other classified imagery-based approaches, for monitoring statuses and trends in biological diversity can greatly improve conservation efforts and habitat management.

scholarly journals Altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in South Korea

2018 ◽  
Author(s):  
Jin-Yong Kim ◽  
Sanghun Lee ◽  
Man-Seok Shin ◽  
Chang-Hoon Lee ◽  
Changwan Seo ◽  
...  
Keyword(s):  
Species Richness ◽  
South Korea ◽  
Habitat Heterogeneity ◽  
Bird Species ◽  
Bird Diversity ◽  
Spring Temperature ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Main Driver ◽  
And Migration

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these remain controversial. This study investigated the causes of altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in Jirisan National Park, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1400 m above mean sea level in the breeding season. A total of 2771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 16 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity, and that density was positively correlated with vertical, but not horizontal, habitat heterogeneity, and negatively correlated with migrant rate. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. And neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.

scholarly journals Autoregressive modelling of species richness in the Brazilian Cerrado

2008 ◽  
Vol 68 (2) ◽  
pp. 233-240 ◽  
Author(s):  
CM. Vieira ◽  
D Blamires ◽  
JAF. Diniz-Filho ◽  
LM. Bini ◽  
TFLVB. Rangel
Keyword(s):  
Species Richness ◽  
Spatial Structure ◽  
Spatial Autocorrelation ◽  
Bird Species ◽  
Information Criterion ◽  
Type I ◽  
Environmental Predictors ◽  
Human Occupation ◽  
Ecological Data ◽  
Bird Species Richness

Spatial autocorrelation is the lack of independence between pairs of observations at given distances within a geographical space, a phenomenon commonly found in ecological data. Taking into account spatial autocorrelation when evaluating problems in geographical ecology, including gradients in species richness, is important to describe both the spatial structure in data and to correct the bias in Type I errors of standard statistical analyses. However, to effectively solve these problems it is necessary to establish the best way to incorporate the spatial structure to be used in the models. In this paper, we applied autoregressive models based on different types of connections and distances between 181 cells covering the Cerrado region of Central Brazil to study the spatial variation in mammal and bird species richness across the biome. Spatial structure was stronger for birds than for mammals, with R² values ranging from 0.77 to 0.94 for mammals and from 0.77 to 0.97 for birds, for models based on different definitions of spatial structures. According to the Akaike Information Criterion (AIC), the best autoregressive model was obtained by using the rook connection. In general, these results furnish guidelines for future modelling of species richness patterns in relation to environmental predictors and other variables expressing human occupation in the biome.

scholarly journals Altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in South Korea

2018 ◽  
Author(s):  
Jin-Yong Kim ◽  
Sanghun Lee ◽  
Man-Seok Shin ◽  
Chang-Hoon Lee ◽  
Changwan Seo ◽  
...  
Keyword(s):  
Species Richness ◽  
South Korea ◽  
Habitat Heterogeneity ◽  
Bird Species ◽  
Bird Diversity ◽  
Spring Temperature ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Main Driver ◽  
And Migration

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these remain controversial. This study investigated the causes of altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in Jirisan National Park, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1400 m above mean sea level in the breeding season. A total of 2771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 16 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity, and that density was positively correlated with vertical, but not horizontal, habitat heterogeneity, and negatively correlated with migrant rate. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. And neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.

scholarly journals Elevational pattern of bird species richness and its causes along a central Himalaya gradient, China

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2636 ◽  
Author(s):  
Xinyuan Pan ◽  
Zhifeng Ding ◽  
Yiming Hu ◽  
Jianchao Liang ◽  
Yongjie Wu ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Anthropogenic Activities ◽  
Bird Species ◽  
Primary Forest ◽  
Central Himalaya ◽  
Wet Season ◽  
Breeding Bird ◽  
Richness Pattern ◽  
Richness Patterns

This study examines the relative importance of six variables: area, the mid-domain effect, temperature, precipitation, productivity, and habitat heterogeneity on elevational patterns of species richness for breeding birds along a central Himalaya gradient in the Gyirong Valley, the longest of five canyons in the Mount Qomolangma National Nature Reserve. We conducted field surveys in each of twelve elevational bands of 300 m between 1,800 and 5,400 m asl four times throughout the entire wet season. A total of 169 breeding bird species were recorded and most of the species (74%) were small-ranged. The species richness patterns of overall, large-ranged and small-ranged birds were all hump-shaped, but with peaks at different elevations. Large-ranged species and small-ranged species contributed equally to the overall richness pattern.Based on the bivariate and multiple regression analyses, area and precipitation were not crucial factors in determining the species richness along this gradient. The mid-domain effect played an important role in shaping the richness pattern of large-ranged species. Temperature was negatively correlated with overall and large-ranged species but positively correlated with small-ranged species. Productivity was a strong explanatory factor among all the bird groups, and habitat heterogeneity played an important role in shaping the elevational richness patterns of overall and small-ranged species. Our results highlight the need to conserve primary forest and intact habitat in this area. Furthermore, we need to increase conservation efforts in this montane biodiversity hotspot in light of increasing anthropogenic activities and land use pressure.

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