A MULTI-METHOD ASSESSMENT OF THE TEMPORAL DYNAMICS OF TREED BOGS IN NOVA SCOTIA, CANADA

Abstract

Peat bogs contribute greatly to carbon storage, fresh water supply and biodiversity maintenance. Some studies have detected a notable shrinking of peat bogs and predicted an accelerating rate of tree establishment, however, there is only few focusing on tree encroachment in bogs in Canada. This study aimed at revealing the processes that influence tree establishment and the temporal-spatial changes in bogs over years in Nova Scotia, Canada. Positions, species, height and mortality of bog trees were measured in Kejimkujik National Park and they were analyzed by spatial point pattern analysis to help understand the underlying establishment processes. In addition, a time series of aerial photos (1928 to 2011) and UAV imagery were assembled to detect long-term tree crown dynamics in two bogs. Results indicate that during the past years, trees have been encroaching in the two peat bogs but encroachment rates are decreasing. The availability of favorable micro sites, competition between trees and drainage-blocking may have facilitated the successful seedling establishment and tree expansion in the two bogs.