We investigated the forest health of red fir (Abies magnifica) and how it compared with commonly-associated species Jeffrey pine (Pinus jeffreyi), lodgepole pine (Pinus contorta) and white fir (Abies concolor) in the upper montane forests of California. We evaluated tree mortality rates, changes in the density of recently-dead trees and the amount of insect and disease damage on live trees from comprehensive forest inventories. The annual mortality rate for red fir was 1.8%, while the rates for Jeffrey pine, lodgepole pine and white fir were 1.9, 1.1 and 3.0%, respectively. The proportion of recently-dead red fir trees increased over time, suggesting an increase in mortality; however, stage-transition models suggested the current population structure of red fir is stable. Dwarf mistletoe and drought-stressed sites were significant predictors of red fir mortality. Trees with substantial damage had a higher probability of experiencing mortality in five years. Our results are consistent with others, but the timeframe is too short to make conclusions about long-term declines. Our results suggest that the most significant of multiple biotic factors involved in red fir mortality processes is dwarf mistletoe, while tree age and the proportion of forest in old-growth may also influence mortality rates.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 22 • No. 1