Canadian Forest Service Publications
Spatial and temporal patterns of fire history and vegetation of dry forests along an elevation gradient in the Arrowstone valley, southern British Columbia. 2012. Arsenault, A. Page 6 in Proceedings, 5th International Fire Ecology and Management Congress: Uniting Research, Education and Management. December 2012, Portand Oregon, USA.
Issued by: Atlantic Forestry Centre
Catalog ID: 34656
Fire has been an important process in shaping the dry Douglas-fir forests of British Columbia’s southern interior. However the spatial and temporal patterns of fire regimes and how they are linked to vegetation and climate have not been investigated thoroughly. We document the spatio-temporal pattern of fire history along an elevation gradient in the Arrowstone valley. The study area is a 6700 ha protected watershed which has experienced only limited human intervention. Interior Douglas-fir occurs throughout the study area while Lodgepole pine dominates at higher elevations. Ponderosa pine occurs on drier sites and tends to be more abundant at lower elevations. Hybrid white spruce and trembling aspen are associated with wetter microsites. Fire history, forest structure and vegetation were assessed in 90 plots located along five 2-km gradsects distributed in different parts of the watershed to capture variation in elevation and topography. A fire chronology was constructed from 143 fire scar samples and spanned a period from 1585 to 2006. Tree ages collected from over 700 tree cores ranged from 30 to 500 years. Additional cores were collected from this valley and nearby Hat Creek to construct a long chronology from 1312 to 2006 which exhibited clear drought patterns associated with high fire years. Historically the landscape was in a state of non-equilibrium with fires of variable size, severity, and frequency. Fire protection records from the BC Forest Service reveals little fire suppression activities in the watershed suggesting that a lengthening of fire intervals for portions of the watersheds are most likely related to changes in climate. Episodic catastrophic fire and insect distur¬bances have played a major role in shaping the structure and composition of these forests reinforcing the idea that interior Douglas-fir forests.