|
Abstract:
|
Climate change is impacting both the distribution and abundance of vegetation, especially in far northern latitudes. The effects of climate change are different for every plant community and vary heterogeneously in both space and time. Small changes in climate could result in large vegetation responses in sensitive communities but weak responses in robust communities. However, patterns of sensitivity and robustness are not yet well understood, largely due to a lack of long-term measurements of climate and vegetation. Fortunately, observations are sometimes available across a broad spatial extent. We develop a novel statistical model for a multivariate response based on unknown cluster-specific effects and covariances, where cluster labels correspond to sensitive vs. robust sites. Our approach utilizes a prototype model for cluster membership that offers flexibility, while enforcing smoothness in cluster probabilities across sites with similar characteristics. We demonstrate our approach with an application to vegetation abundance in Alaska, USA in which we leverage the broad spatial extent of the study area as a proxy for unrecorded historical observations.
|
