Secondary Plant Compounds in Seedling and Mature Aspen (Populus tremuloides) in Yellowstone National Park, Wyoming

Abstract

Abstract Widespread establishment of seedling aspen (Populus tremuloides) occurred in Yellowstone National Park (YNP) following the extensive1988 fires. Aspen stands occupy ∼2% of YNP and aspen stems are intensively browsed by native ungulates. Chemical composition, especially secondary compounds, may influence levels of herbivory and, hence, survival of aspen, but concentrations of such compounds in aspen in the northern Rocky Mountains are not known. Quantitative profiles of foliar nitrogen and secondary compounds (condensed tannins and the phenolic glycosides, salicortin and tremulacin) in aspen were assessed to address the following questions: (1) Do concentrations of secondary compounds differ between seedling and mature aspen stands? (2) Do concentrations of secondary compounds in seedling aspen differ between unbrowsed and artificially browsed seedlings? (3) Among mature aspen stands, do concentrations of secondary plant compounds differ among, (a) burned and browsed, (b) unburned and browsed and (...