scholarly journals Climate mediates the effects of disturbance on ant assemblage structure

2015 ◽  
Vol 282 (1808) ◽  
pp. 20150418 ◽  
Author(s):  
Heloise Gibb ◽  
Nathan J. Sanders ◽  
Robert R. Dunn ◽  
Simon Watson ◽  
Manoli Photakis ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Anthropogenic Disturbance ◽  
Global Scale ◽  
Habitat Disturbance ◽  
Assemblage Structure ◽  
Arid Environments ◽  
Global Database ◽  
Low Precipitation ◽  
Impacts Of Climate Change

Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk.

Evaluation of the Impacts of Climate Change on Land Suitability for Jatropha Cultivation

2014 ◽  
Vol 955-959 ◽  
pp. 3777-3782 ◽  
Author(s):  
Xiao Feng Zhao ◽  
Bin Le Lin
Keyword(s):  
Climate Change ◽  
Rank Order ◽  
Global Scale ◽  
Land Suitability ◽  
Climate Change Scenarios ◽  
Climate Scenarios ◽  
The West ◽  
The North ◽  
North And South ◽  
Impacts Of Climate Change

We evaluated land suitability for Jatropha cultivation at a global scale under current and future climate scenarios. Areas that are suitable for Jatropha cultivation include southern South America, the west and southeast coasts of Africa, the north of South Asia, and the north and south coasts of Australia. In the predicted climate change scenarios, areas near the equator become less suitable for Jatropha cultivation, and areas further from the equator become more suitable. Our analyses suggest that the rank order of the six climate change scenarios, from the smallest to the largest effects on Jatropha cultivation, was as follows: B1, A1T/B2, A1B, A2, and A1FI.

scholarly journals Illustrating a new approach to estimating potential reduction in fish species richness due to flow alteration on a global scale

2013 ◽  
Vol 10 (6) ◽  
pp. 7837-7856 ◽  
Author(s):  
S. Yoshikawa ◽  
A. Yanagawa ◽  
A. Khajuria ◽  
P. Sui ◽  
Y. Iwasaki ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Fish Species ◽  
Statistical Models ◽  
River Discharge ◽  
Global Scale ◽  
The Other ◽  
Freshwater Ecosystem ◽  
Global Simulation ◽  
Flow Alteration

Abstract. Changes in river discharge due to human activities and climate change would affect the sustainability of freshwater ecosystem. In order to globally assess the future status of freshwater ecosystem under regime shifts in river discharge, global-scale hydrological simulations need to be connected with a model to estimate the soundness of freshwater ecosystem. However, the explicit combination of those two on a global scale is still in its infancy. A couple of statistical models are introduced here to link flow regimes to fish species richness (FSR): one based on a linear relationship between FSR and mean river discharge, and the other based on a relationship between FSR and ecologically relevant flow indices involving other several flow characteristics as well as mean river discharge. The former one has been sometimes used in global simulation studies, but the latter one is newly introduced here in the context of global simulation. These statistical models for estimating FSR were combined with a set of global river discharge simulations to evaluate the potential impact of flow alterations due to climate change on FSR changes. Generally, future reductions in FSR by the latter method are larger and much more scattered rather than by the former method. In arid regions, both models provide reductions in FSR because mean discharge is projected to decrease from past to future, although the magnitude of reduction in FSR is different. On the other hand, large reductions in FSR only by the latter model are detected in heavy-snow regions due to the increases of mean discharge and frequency of low and high flows. Although we need further research to conclude which is more relevant, this study demonstrates that the new model could show a considerably different behavior in assessing the global impact of flow alteration on freshwater ecosystem change.

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