TY - JOUR
T1 - Holocene precipitation in the coastal temperate rainforest complex of southern British Columbia, Canada
AU - Brown, K.J.
AU - Fitton, R.J.
AU - Schoups, G.
AU - Allen, G.B.
AU - Wahl, K.A.
AU - Hebda, R.J.
N1 - Funding Information:
The authors would like to thank the Natural Sciences and Engineering Research Council of Canada for providing operating Grant no. OGP0090581 to Richard Hebda; the Univeristy of Victoria, Canada, for graduate student funding; Ross Benton of the Pacific Forestry Centre, Canada, for kindly allowing use of GIS resources; Benny Schark of the Geological Survey of Denmark and Greenland for helping with figures; and Dave Gillan, Qibin Zhang, Rob Hewlett, Richard Bradshaw, and Pat Bartlein for their various contributions. We also would like to express our sincere gratitude to the two anonymous reviewers who constructively assessed the manuscript and provided thoughtful comments.
PY - 2006/11
Y1 - 2006/11
N2 - Pollen data from 69 surface samples from Vancouver Island, Canada, were used to develop a ratio index of precipitation, Douglas fir-western hemlock index (DWHI). DWHI ratios were combined with interpolated estimates of mean annual precipitation to develop pollen-based precipitation transfer functions. The optimal regression model, with a predictive range of 960-2600 mm, was applied to 10 Holocene lake sediment records distributed across a ∼150 km long coastal-inland precipitation gradient. Predicted precipitation was spatially modelled in a geographic information system to examine the spatio-temporal history of precipitation from this representative portion of the coastal temperate rainforest (CTR) complex of western North America. The reconstructions show widespread early Holocene dry conditions coupled with a steep east-west precipitation gradient. Thereafter, the modern precipitation gradient established 7000 years ago, illustrating that the CTR complex has experienced marked short-distance east-west changes in precipitation in the past. Changes in the abundance of arboreal and non-arboreal vegetation, as well as fire disturbance, are often concomitant with changes in Holocene precipitation. Given the precipitation and vegetation history of the region, conservation initiatives should focus on the moist outer coastal zone since it appears to have the greatest amount of resilience to perturbations in precipitation, whereas monitoring programs for signs of climate change should be initiated in central and eastern areas as they appear sensitive to changes in the moisture regime.
AB - Pollen data from 69 surface samples from Vancouver Island, Canada, were used to develop a ratio index of precipitation, Douglas fir-western hemlock index (DWHI). DWHI ratios were combined with interpolated estimates of mean annual precipitation to develop pollen-based precipitation transfer functions. The optimal regression model, with a predictive range of 960-2600 mm, was applied to 10 Holocene lake sediment records distributed across a ∼150 km long coastal-inland precipitation gradient. Predicted precipitation was spatially modelled in a geographic information system to examine the spatio-temporal history of precipitation from this representative portion of the coastal temperate rainforest (CTR) complex of western North America. The reconstructions show widespread early Holocene dry conditions coupled with a steep east-west precipitation gradient. Thereafter, the modern precipitation gradient established 7000 years ago, illustrating that the CTR complex has experienced marked short-distance east-west changes in precipitation in the past. Changes in the abundance of arboreal and non-arboreal vegetation, as well as fire disturbance, are often concomitant with changes in Holocene precipitation. Given the precipitation and vegetation history of the region, conservation initiatives should focus on the moist outer coastal zone since it appears to have the greatest amount of resilience to perturbations in precipitation, whereas monitoring programs for signs of climate change should be initiated in central and eastern areas as they appear sensitive to changes in the moisture regime.
UR - http://www.scopus.com/inward/record.url?scp=33751211828&partnerID=8YFLogxK
U2 - 10.1016/j.quascirev.2006.02.020
DO - 10.1016/j.quascirev.2006.02.020
M3 - Article
VL - 25
SP - 2762
EP - 2779
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
SN - 0277-3791
IS - 21-22
ER -