Temperature is an important limitation to forest growth, especially at higher elevations. A warmer temperature can extend the growing season and thus enhances vegetation growth. There are projections that increasing temperature during dry periods will intensify drought effects on vegetation. Thus, studying the effect of rising temperature on vegetation moisture content is essential to understand the moisture stress of vegetation under a warming climate. Ram Ray, Research Scientist, and his colleagues from the University of California Merced evaluated the relative vulnerability of sequoia groves (evergreen forest) in Sierra Nevada Mountain, California under a warming climate and multiyear dry periods using remotely sensed data. Results showed that increasing biomass and temperature had caused an increase in evapotranspiration, which signifies an increasing vulnerability to multiyear dry periods. On the other hand, multiyear subsurface water stage may be insufficient to make up for water loss. Results also showed that change in vegetation wetness is elevation dependent and vegetation growing in an area with lower topographic wetness index has a greater loss of wetness during a warm drought.
Ray participated in this research during his tenure at the Sierra Nevada Research Institute, University of California Merced. More details about this work can be found in the recently published article “Emerging stress and relative resiliency of Giant Sequoia groves experiencing multi-year dry periods in a warming climate” in the Journal of Geophysical Research: Biosciences of American Geophysical Union (AGU) publications at these links:
http://onlinelibrary.wiley.com/doi/10.1002/2017JG004005/full
Haimanote Bayabil, Ph.D.
Post-doctoral Researcher, Natural Resources and Environmental Systems Research
(936) 261-5021
hkbayabil@pvamu.edu