Background: Since the future climate is predicted to be more extreme even in the case of semi-arid conditions, data on such conditions will be more important in the global context.
Aims: The current work focuses on the effects of precipitation control on soil microorganisms in deciduous wild forest ecosystems in northeast China.
Methods: To study the amount of rainwater reaching forest litter and determine the effect of rainfall on leaf mass loss, respiration rate, and microbial biomass, three regimes with six repetitions were applied: 1) full coverage (100% reduction in precipitation); 2) partially covered areas (50% reduction); and 3) completely open areas.
Results: Rainwater did not reach entirely covered areas. Similarly, coverage did not always impact soil respiration and microbial biomass. Massive losses of fully open and partially covered litter were 20-35% larger than those of closed litter. Mass loss of the five litter types was in the following order: Ulmus japonica>Quercus mongolica>Fráxinus mandshurica>Juglans mandshurica>Tilia amurensis. Respiration intensity from closed litter decreased in all species six months after planting. For one year, a significant effect of the closed plot was observed only on U. japonica and Q. mongolica litter. An exception was noted for T. amurensis since three months after planting, microbial biomass values were comparable, irrespective of the extent of cover closure. According to the results of the experiment, precipitation on partially covered plots of the five litter types was reduced by approximately 45-50%.
Conclusion: The absence of precipitation had an adverse effect on some biological processes in the litter but had a sporadic effect on soil processes. The lack of precipitation, although soil moisture was maintained, may have had an impact on the organic matter cycle in forest litter.