The analysis of phytophagous mammals’ excretory activity in forest ecosystems

In this paper the author considers the excretory activity as one of zoocenosis environment-transforming activity types. The paper presents the results of experimental data on the effect of phytophagous animals’ excreta on the soil-forming processes through adding organic substances to the soil in the process of decomposing the undigested plant residues. The organic substance (humus) is a source of mineral elements necessary for plant organisms. The value of phytophagous animals’ excreta is in their peculiar properties such as high content of humic acids performing a number of important functions in the biosphere. In this paper one of these functions – accumulative – has been considered. Decomposition of the organic substance in the form of the excreta of the elk (Alces alces, L.) as the largest phytophagous animal of the north-west proceeded in the course of the experiment in natural and laboratory conditions. Anthropogenically disturbed areas of the Vologda Region have been chosen as natural conditions. The excreta decomposition took place on medium-loamy and strongly podzolic soils on the cutting site after clear felling in the sorrel spruce forest. In laboratory conditions the experiments on excreta decomposition have been carried out in microlysimeters. Thereby we have chosen the three factor experiment with subsequent developing mathematical models (regression equations). We have used the winter variety of the elk’s excreta which differs in composition from the summer variety. Winter excreta appear as a result of digesting the coarse woody feeds. In the paper the results of the research on the group composition of humus and agrochemical NPK-complex have been given. As a result of decomposition it has been revealed that the content of the humus components under study and NPK have been influenced by the size of particles in the soil, microconditions and the time of organic substance decomposition.