Tropical-Temperate Ecohydrological Connectivities: Assessing Ecoclimate Teleconnections Related to Tree Die-off Events

Abstract:

Ecohydrological processes in one region can potentially be affected by ecolohydrological processes in a distant region through ecoclimate teleconnections. When change in vegetation cover of sufficient magnitude occurs in one area, it can alter microclimate conditions not only there, but through climate connections can impact ecosystems elsewhere. We are developing an approach to assessing ecoclimate teleconnections that is tied to one of the largest-scale vegetation change processes driven directly by climate change: drought- and heat-related tree die-off events. Our approach includes six steps: (1) What is the probability of vegetation change (in this case due to tree die-off) in a given location?; (2) How does the land surface change in terms of vegetation structure?; (3) How does the vegetation-structure change influence albedo and other components of land surface energy balance?; (4) What are the consequences of the changes in vegetation structure and energy balance for the region?; (5) What climate teleconnections link the initially impacted region to other regions?; and (6) What type of secondary ecological impacts does this produce in another teleconnected region of interest? We initially focused on potential connections between temperate western North American forests and tropical Amazon forests, but are also examining other intra- and inter-continental connections. In our approach, we use experimental data to drive tree die-off estimates, field campaigns to relate changes in vegetation structure to changes in albedo and other aspects of microclimate, and global vegetation models to identify locations, magnitudes and mechanisms of potential ecoclimate teleconnections within and beyond tropical regions. Ecoclimate teleconnections present a new frontier for assessing tropical ecoclimate teleconnections at intra- and inter-continental scales.