Climate change predictions of increases in climate extremes, such as drought, have come with expectations that such events will produce large impacts to ecosystems. However, it is often the case that climatically extreme conditions do not produce extreme ecological responses. This raises questions as to what characteristics of climate extremes (e.g. magnitude vs. duration) are most likely to produce large ecological responses. Here, I utilize both experimentation and data synthesis to develop insight as to what characteristics of climate extremes may tend towards driving reduced ecological resilience to these events. First, I introduce and discuss the results of a novel, cross-ecosystem experimental approach that imposed gradients of precipitation amount and extremity while controlling for precipitation patterns. I then synthesize results from prior precipitation manipulation experiments. In particular, I explore how 1) intra-annual variability or timing (e.g. rainfall patterns), magnitude (e.g. 1st vs. 15th percentile), and duration (e.g. 1 vs. 2 years) influences ecosystem sensitivity to extremes.
Results/Conclusions
Preliminary results suggest important interactions between intra- and inter-annual climatic variability. For example, I find that intra-annual rainfall patterns can significantly impact the magnitude of ecosystem sensitivity to severe growing season drought. Further data suggests multi-year periods and/or conditions beyond what has been historically experienced may be required before ecosystem functions exhibit large response thresholds. Thus, while ecosystems do often exhibit responses to climatically extreme years, it is likely that movement beyond what has been historically experienced by the system is what will ultimately drive large reductions in function and thus extreme ecosystem responses. Further research will explore these dynamics within prior experiments in order to add clarity to these initial insights.