Resource bottlenecks – periods of severe restriction in resource availability – can be triggered by increased climate variability. This is believed to represent an important mechanism through which climate change will affect biodiversity and yet little is understood about its potential impact. Martine Maron and colleagues recently reviewed the topic. They synthesized the key global change processes that might exacerbate the severity of bottlenecks in resource availability on animal populations, and outlined how adaptation responses can help buffer the impacts.
They collated examples from the literature of population-level impacts of resource bottlenecks induced by extreme weather and climate events to explore the types of population impacts that have most frequently been recorded, and the type of extreme events associated with them. They then developed a conceptual framework that captures the factors contributing to species’ vulnerability to climate-induced resource bottlenecks (in time and space) in increasingly variable environments.
They found forty-nine instances of population-level impacts from climate-induced resource bottlenecks in the published literature, including four extinctions and ten population crashes. Anthropogenic land-use change interacts with increasing climatic variability to exacerbate these resource ‘crunches’. In some instances, however, they can sometimes also act as a buffer for species.
Resource bottlenecks are likely to be a large class of climate-sensitive stressors whose impacts may play out at the population scale, even well within a species’ apparent climatic envelope. More effective conservation responses to climate-related threats include managing protected area networks for spatial and temporal resource complementarities and other targeted actions to buffer vulnerable species against bottlenecks.
Maron M, CA McAlpine, JEM Watson, S Maxwell & P Barnard (2015). Climate-induced resource bottlenecks exacerbate species vulnerability: a review. Diversity and Distributions 21: 731–743. http://onlinelibrary.wiley.com/doi/10.1111/ddi.12339/full