• Redding, Erin Joelle
  University of Maine Graduate School
  

Annual development events in biological systems are dependent, in part on environmental conditions. They are valuable bio-indicators of shifting climate, making the science of phenology an essential component of climate change research. Many studies have been done on the effects of temperature and photoperiod on phenophases, but fewer have explored the consequences of nutrient availability in terrestrial ecosystems.

The Bear Brook Watershed in Maine (BBWM) provides an opportunity to evaluate morphological and chemical phenology as influenced by decadal-scale experimental ecosystem acidification and nitrogen (N) enrichment. BBWM is a paired watershed study designed to assess responses to a changing chemical and physical climate. The West Bear (WB) watershed has been treated bimonthly with (NH4)2SO4 since 1989; the East Bear (EB) watershed serves as a reference. Significant differences have been found between the WB watershed and the EB watershed with respect to biogeochemical cycles affecting essential plant nutrients.