An emerging theory centering around the role of plants in the climate system
Key Points & Overview
- Regional forest loss can have a measurable impact on forest productivity elsewhere in the world.
- Forest loss in the Western United States is reducing productivity of forests and croplands in the Eastern United States.
A seemingly remote event in one part of the globe having an impact on other regions across the globe is often referred to as a “climate teleconnection”. It is commonly understood that the El Niño-Southern Oscillation (ENSO), a quasi-cyclic fluctuation in the sea-surface temperatures of the Pacific Ocean and the air pressure of the atmosphere above, is a climate teleconnection; these fluctuations modify the general flow of the atmosphere, having a profound effect on the normal weather conditions in many parts of the world. Still, a key question remains debated: could there be other types of teleconnections connecting components of the global climate system?
Recent work by Abby Swann, an assistant professor of the Department of Atmospheric Sciences and Department of Biology, Marysa Lague, a graduate student in the Department of Atmospheric Sciences, and Elizabeth Garcia, a postdoctoral fellow in the Department of Atmospheric Sciences, suggests that this is indeed possible. The group, along with a number of coauthors, demonstrated that forest loss in one part of the United States can drive productivity of forests in other regions of the United States.
Using complex models that describe how the Earth system behaves, the group of researchers removed forests in certain regions of the United States and analyzed the response. When forests in the southwestern United States were removed, areas in the eastern United States warmed slightly, causing forest productivity in those areas to decline. Removing forests near the Mid-Atlantic United States, however, helped Midwestern forests grow. Swann and her colleagues refer to these events as ecoclimate teleconnections: where ecosystems in one location impact climate and ecosystems in another location through changes in atmospheric circulation. For instance, the loss of forests in the southwestern United States decreased the amount of water transpired to the atmosphere, changing atmospheric circulation and subsequently warming areas of the eastern United States. This warming resulted in an ecological response, causing a decrease in plant productivity.
This work helps to refine our understanding of how the Earth system works and demonstrates the importance of considering ecoclimate teleconnections when trying to meld macro-biology with global-scale ecology.