ABSTRACT
Forested wetlands on organic soils in Canada have low productivity resulting from the high water table, cold substrate temperature, and poorly aerated soil conditions. This chapter aims to evaluate the effects of clearcutting and thinning on water table levels in the Clay Section of Northern Ontario. Precise evaluation of the impact of protecting advanced growth on the hydrology of forested wetlands is lacking. Measurements of water table levels were initiated in 1988 and were continued in 1989 and 1990 as the preharvest calibration period. The increased amount of water available on the site has considerable consequences in forested wetlands since the hydrological regime is the main environmental driving force. The effect of clearcutting on the water table level was evaluated using calculated regression equations for the calibration period and for 2 years after harvesting. Water table fluctuations were directly related to the amount and frequency of precipitation.
