4. Discussion
Seasonal changes in soil moisture content were frequently
reported to affect microbial populations and their activities in forest
Table 4
Predicted difference between enzyme activities and microbial biomass content in soil samples with high moisture content and in samples with low moisture
content expressed as a percentage of the activity in the samples with high moisture content predicted by linear regression models. The data were derived fromlinear regression curves and calculated as a difference between samples with moisture content 0.40 g g−1 versus 0.70 g g−1 in the L horizon and between 0.30 and 0.60 g g−1 in the H horizon and are expressed as a percentage of the value in the wet soil. Values in parentheses represent the same difference calculated using
the fit representing the 95% probability limit and actually represent the minimal level of soil moisture effect at that probability level; n.s. indicates variables where linear regression was not significant at P < 0.05. For example, the linear model predicts that the L horizon samples collected in May with 0.40 g g−1 soil moisture content contain by 59% less PLFAT found in samples with 0.70 g g−1 and that the difference is at least 31% at P < 0.05.