T39 Lakes of the World through Time and Space I

Monday, 26 October 2020
5:30 PM - 8:00 PM
Meeting Rooms

PALEOECOLOGICAL INDICATORS AND CARBON DYNAMICS IN LAKE SEDIMENTS ACROSS WESTERN CANADA IMPLICATIONS FOR PROTECTED AREA MANAGEMENT

Paper number: T39-9
Program: Technical Sessions
Time: 6:40 PM – 6:50 PM

Authors

Abstract

Lake sediment from 18 lakes across western Canada was studied in regards to carbon accumulation rate over the last 150 years. Carbon (C) accumulation rate was found to be 3.8 times greater on average in the modern time period (1980-2010) when compared to the historical time period (1830-1860). The largest C accumulation rate change was found in the Boreal Plains ecozone. Maximum lake depth, lake geometry ratio, and temperature related climate variables (e.g., number of ice free days) were significantly correlated to C accumulation rate. There was not a statistically significant difference between lake C accumulation rate between protected and non-protected lakes.

To better understand how climate controlled millennial forces of vegetation composition and fire related to carbon accumulation, paleo proxies of pollen and charcoal were investigated on two longer sediment cores in adjacent biogeoclimatic zones of the Kootenay Valley of British Columbia. Broad-scale climatic controls are interpreted as the major influence on high fire frequency and carbon accumulation rate in the dry and hot xerothermic period (11,500-8,000 cal. yrs BP). The Kootenay Valley is expected to return to xerothermic-like climate conditions within the next century. The conversation pertaining to how protected areas would manage for carbon in the future began with a workshop exploring how to frame carbon management. Experts were then interviewed and ecological integrity measures were determined to be the best place for carbon to act as either a co-benefit or as a separate ecological integrity measure. A survey of protected area manager perspectives on the importance of each ecological integrity measure to carbon management was created. Vegetation-related ecological integrity measures were found to have the most importance to co-benefit carbon management. Active management in protected areas should use paleo proxies to find reference biogeoclimatic zones and restoration efforts should focus on retaining carbon on the landscape through maintenance of vegetation-related ecological integrity measures like prescribed burning.

Geological Society of America Abstracts with Programs. Vol. 52, No. 6

doi: 10.1130/abs/2020AM-352767

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