Identifying which ecosystems are close to the tipping points is key to gaining an understanding of global resilience.
Increasing spatial and temporal variance in key biodiversity indicators has been shown to provide early warning signals of an ecosystem heading towards a tipping point. Additionally, it has been hypothesised that human activity has been changing the scale of spatial and temporal variability, and it is therefore crucial to identify the drivers of both increasing and decreasing spatial and temporal variability.
Here, we use an index of disconnects between local and global variability of three essential biodiversity variables to (1) identify ecoregions at risk, and (2) establish the relationship between changing variability, human activity and climate anomalies.
We show that many ecoregions are showing increasing or decreasing variance, and that this tends to be driven by human land-use pressure, rather than climate anomalies. These human pressures have the strongest effect on the change in spatial variance in forested ecoregions in the tropics.
Dr Laura Graham is a spatial ecologist at University of Birmingham. She is currently working on a IIASA-NERC funded fellowship to develop a mechanistic understanding of the relationship between fragmentation (or, more broadly, landscape structure) and biodiversity.
Prior to this, Laura undertook a postdoc at University of Southampton examining the scaling rules of ecosystem services, and one at Stony Brook University on understanding climate change effects on hummingbirds. Laura did her PhD at University of Nottingham on metapopulation modelling of urban planning scenarios.