PARENT SESSION
Oral Session #30: Landscape Ecology: Dynamics and patterns. Presiding: A. Hansen.
Tuesday, August 7, 2001. 1:00 PM to 5:00 PM. Madison Ballroom D.

Regeneration characteristics of quaking aspen stands in Lake Tahoe Basin, Sierra Nevada.

Ko, Dong¹, Taylor, Alan¹, ¹

ABSTRACT- There has been growing concern over the decline of quaking aspen (Populus tremuloides) in the western forests of United States. A number of studies suggested that quaking aspen stands are declining due to suppression of frequent fire and increased grazing associated with Euro American settlement. Aspen also occurs in California, and similar environmental changes have occurred, but there is no identified scientific documentation on aspen population dynamics in the area. In this study, we identified age and stand structure in twenty quaking aspen stands in the Lake Tahoe Basin in California, to determine whether quaking aspen is declining due to the similar environmental change. Our results show a wide range of establishment patterns. Five stands are shifting in composition and even will be replaced by shade-tolerant conifer species, while in twelve stands the aspen populations are stable with evidence of self replacement. Three stands showed active regeneration of both aspen and conifer species. Local logging and fire history may contribute to the wide range of regenerative patterns. Our data suggest that quaking aspen dynamics is more complex than other studies suggest. Consequently, this suggests the development of more elaborate forest management strategies to maintain aspen stands in Sierra Nevada, especially when considering the strong emphasis on conifer species in the current management approach.

KEY WORDS: quaking aspen (Populus tremuloides), aspen dynamics, California-Sierra Nevada, stand structure analysis