@mastersthesis {728,
	title = {Age structure and fire disturbance in the southern Sierra Nevada subalpine forest},
	volume = {M.S.},
	year = {1991},
	school = {University of Arizona},
	abstract = {I used age structure to examine the role of fire disturbance and climate on the population dynamics of the subalpine forest in the southern Sierra Nevada. I cored trees on ten 0.1 ha plots (3300-3400 m elevation) that varied in species composition, from single-species foxtail pine (Pinus balfouriana) or lodgepole pine (Pinus contorta, var. murrayana), to mixed-species stands of both pines. Crossdating was used to produce accurate dates of tree recruitment and fire events. Age structure varied by plot species composition: lodgepole pine recruitment pattern is pulsed, sometimes forming single-cohort patches in response to fire; foxtail pine plots have a more steady pattern of recruitment; mixed-species plots show an intermediate recruitment pattern. Fire may maintain a species composition mosaic in the subalpine forest. Foxtail pine regeneration may increase in areas opened by fire, although not immediately following fire. Low-intensity fire may spread over areas larger than previously reported under certain conditions in the subalpine zone. In addition, unusually frequent, extreme, and/or extended periods of drought may severely limit subalpine tree regeneration. Growing season frost events and grazing before 1900 may also have affected trees establishing in the subalpine zone.},
	url = {http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=747829851\&sid=7\&Fmt=2\&clientId=43922\&RQT=309\&VName=PQD},
	author = {MaryBeth Keifer}
}
