Category: Ecological Research
Title: Variability of Warm/Dry Mixed Conifer Forests in Southwestern Colorado, USA: Implications for Ecological Restoration
Author: * Korb, J.E. , * Fule, P.Z., Wu, R.
Subject: Mixed conifer, Colorado, Variability
Abstract: There is a need to quantitatively describe forest types and their associated natural ﬁre regimes in the western US to understand their variability and to develop strategies to restore ﬁre dependent landscapes to reduce ecological problems that might ensue from forest structure and ﬁre regime generalizations. We established three study sites in warm/dry mixed conifer across a west–east transect in southwestern Colorado to determine variability in the historical ﬁre regime and ﬁre–climate relationships and to quantify how diverse warm/dry mixed conifer forest composition and structure are along the same west–east transect. At each study site we collected cross-sections from dead ﬁre-scarred trees to reconstruct ﬁre history and established study plots to characterize forest structure. The three warm/dry mixed conifer sites exhibited different ﬁre histories. One site was characterized by numerous smaller ﬁres as well as larger ﬁres that appeared to burn most of the study site with the other two study sites characterized by relatively infrequent, large ﬁre events. There were more unique ﬁre years at each site than synchronous ﬁre years shared by any sites. Current forest stand structure, after extended ﬁre exclusion and past logging across the three sites, also varied with a reverse-J distribution indicating strong dominance by small trees for two of the study sites and a truncated age distribution at the other site.Our research illustrates that historical ﬁre regime variability exists within the same vegetation type in a relatively small, 50km, geographic locality emphasizing the role that other topographic variables play in determining ﬁre regimes and forest structure. Our ﬁndings demonstrate the need to develop site-speciﬁc reference conditions and for managers to exercise caution when extrapolating ﬁre regimes and forest structure from one geographic locality to another given a projected warmer climate making conditions more favorable to frequent, large wildﬁres.
Source: Forest Ecology and Management
Publisher: Elsevier Science B.V