Surface pool dynamics and climate in boreal peatland of the La Grande River watershed

A study was conducted to investigate the influence of climate on the morphological changes of boreal peatlands of the La Grande (LG) River watershed. In particular, changes in 100 pools from 3 boreal peatlands of different trophic status were examined in relation to their regional meteorological data. Aerial photographs from 1977 and 1999 were used to measure area, perimeter, length and width axes of 35 pools in each of the 3 peatlands from LG1, LG2 and LG3. Results show changes in size and shape of pools during the studied periods. The total area covered by pools decreased between 1977 and 1999. At LG1, a decrease of 246 m2 was measured between 1986 and 1990. At LG2, the total area covered by pools decreased by 3320 m2 between 1984 and 1999, and at LG3 the area decreased by 2634 m2 between 1979 and 1988. The changes appear to be related to seasonal or inter-annual variations of precipitation and evapotranspiration regime. Spatial variability response of pools to changes in hydrological condition indicates their different level of sensitivity