Die Bodenkultur - Journal for Land Management, Food and Environment

A. Bruckner:

Temperature variability and fluctuation in the humus layer of a temperate deciduous forest in spring: implications on the resident fauna

Summary

The temperature of forest floor humus during spring was studied in a cool-temperate beech stand. Before bud break, temperatures in the L horizon peaked at 20-40° C on clear days due to high insulation through the open canopy. Diurnal and short-term variability were very high, with extreme shifts of up to 13.0 to 18.5° C within a 5 to 15 minute span. After leaf expansion, temperature fluctuations were greatly reduced in the L horizon and temperatures rarely exceeded 25° C. The F and Ah horizons were much cooler and wetter than the L horizon, exhibiting minimal diurnal and short-term variability during the entire study. Temperatures and the temporal temperature variability in the F and Ah horizons were always very similar and were largely independent of depth. The spatial variability of temperature at the F - Ah boundary between different microsites was low. The L horizon of temperate deciduous forests can therefore be a hostile and unpredictable environment for humus-dwelling animals. In contrast, conditions in the deeper horizons are cool, moist and very stable, and therefore are more favorable to the resident fauna. Key words:  soil ecology, soil fauna, humus stratification, variability.