Fire-induced shifts in overstory tree species composition and associated understory plant composition in Glacier National Park,Montana |
| |
Authors: | David A McKenzie Daniel B Tinker |
| |
Institution: | (1) Program in Ecology and Department of Botany-3165, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, USA |
| |
Abstract: | In Rocky Mountain forests, fire can act as a mechanism of change in plant community composition if postfire conditions favor
establishment of species other than those that dominated prefire tree communities. We sampled pre and postfire overstory and
postfire understory species following recent (1988–2006) stand-replacing fires in Glacier National Park (GNP), Montana. We
identified changes in relative density of tree species and groups of species (xerophytes vs. mesophytes and reseeders vs.
resprouters) in early succession. Postfire tree seedling densities were adequate to maintain prefire forest structure, but
relative densities among species were variously changed. Changes were directly related to individual species’ response to
severe fires. Most notably, relative density of the mesophytic resprouter quaking aspen (Populus tremuloides) and the xerophytic reseeder lodgepole pine (Pinus contorta) increased substantially following fire, with a concomitant decline in proportional abundance of other tree species that,
in some cases, dominated stands before fire. Trends identified in our study suggest that forest community shifts toward those
dominated by lodgepole pine and quaking aspen are occurring in GNP. Cover of understory species was not affected by tree species
composition or density. These forest communities will likely change throughout succession with the addition of shade-intolerant
species in early seral stages and shade-tolerant species later in succession. However, with increased fire frequency, the
lodgepole pine-dominated postfire communities observed in our study may become more common throughout time. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|