Aspen phenology monitoring in the Central Alaska Network of the National Park Service: Progress report 2010
Dates
Year
2011
Citation
Roland, Carl, and Nicklen, E. Fleur, 2011, Aspen phenology monitoring in the Central Alaska Network of the National Park Service: Progress report 2010: Naional Park Service Natural Resource Stewardship and Science National Park Service: Fort Collins, Colorado, v. NPS/CAKN/NRTR—2010/501.
Summary
We examined the phenology, or the timing of biological events, in aspen trees in interior Alaska. Specifically, we observed the dates of leaf out, flowering and fall senescence in aspen in plots in parks within the Central Alaska Network. We first examined six years of aspen phenology observations taken from two very different areas (one a steep, dry, south-facing area and one a flat, mesic area) within Denali National Park. We then compared the phenology of aspen from similar habitats (both flat and mesic) in different parks: Denali National Park and Wrangell St. Elias National Park. We made correlations between climate variables and phenology benchmarks. We also investigated differences in flowering and bud burst between female and [...]
Summary
We examined the phenology, or the timing of biological events, in aspen trees in interior Alaska. Specifically, we observed the dates of leaf out, flowering and fall senescence in aspen in plots in parks within the Central Alaska Network. We first examined six years of aspen phenology observations taken from two very different areas (one a steep, dry, south-facing area and one a flat, mesic area) within Denali National Park. We then compared the phenology of aspen from similar habitats (both flat and mesic) in different parks: Denali National Park and Wrangell St. Elias National Park. We made correlations between climate variables and phenology benchmarks. We also investigated differences in flowering and bud burst between female and male trees. Generally, we found the two Denali aspen trees had similar phenology in both the spring and fall. The Denali and Wrangell St. Elias aspen trees had different timing for leaf out, but similar timing for senescence. In general we found spring leaf out was highly correlated with late spring temperatures, while the onset of senescence was correlated with a minimum temperature being reached and progression of senescence was correlated with growing season rainfall. Our data do not rule out the importance of photoperiod as a controlling factor in leaf senescence. We also found that male and female trees differ in their timing of flowering and leaf out.