HOLOCENE CARBON DYNAMICS IN SOUTHERN BRITISH COLUMBIA'S FORESTS: A PALEOECOLOGICAL PERSPECTIVE

In this study we use a multi-proxy paleoecological approach to understand the dynamics of carbon in lacustrine systems as it pertains to carbon storage, acquisition, and release. Pollen and carbon analysis of lake sediments was undertaken in order to test the concept that vegetation zones interpreted using pollen analysis can be used to infer carbon storage on the landscape as well as in lacustrine systems. Dog Lake in Kootenay National Parks Interior Montane Spruce zone and 3M Pond in the Engelmann Spruce Subalpine Fir zone in the northern Cascade Mountains of British Columbia were used to test this concept. Among the two study sites; pollen, charcoal, plant macrofossil, and Chironomid head capsule analyses indicate that large scale changes in climate throughout the Holocene have drastically altered ecosystem composition and natural disturbance regimes over the last 10,000 14C yr BP. In particular, temperatures during the early Holocene Xerothermic period were up to 4C warmer than present, hence allow for a potentially analogous climate regime to future temperature increase over the next century. Using actual measurement of carbon in lake sediments, as well as inferring landscape carbon values in the past from a combination of paleoecological forest zone interpretation and the Canadian Forest Service CBM‐CFS3 model, we compare how much carbon was stored on the landscape based on paleoecological data to that estimated from forest carbon accounting systems. These data help us refine our understanding on ecosystem level changes in carbon dynamics based on both empirical data and modeled scenarios.