Evaluation of the bottom-up force of accumulated organic matter on microarthropods in a temperate forest floor

A microarthropod community established in artificial soil containing different amounts of organic matter was examined to evaluate the community response to organic matter. On a forest floor of a cypress stand, mesh boxes were filled with grains of perlite, a porous mineral material, mixed with three different quantities (0, 1.55, and 3.1 gC L−1) of organic matter, which was collected by sieving (φ 2 mm) the accumulated organic layer of the forest floor. Soils in the boxes were sampled after 6 months of field incubation and the animals were extracted and identified. The abundance of Collembola, Oribatida, and Prostigmata positively correlated with organic matter content. Based on the results, 1 gC of organic matter was estimated to have the potential to support 106 Collembola, 81 Oribatida, and 130 Prostigmata. This estimation suggests that existing organic matter in the studied forest is sufficient in quantity to support microarthropods.

► We examined effect of soil organic matter on the microarthropods’ abundance.
► Mesocosms to minimize the effect of physical factors were constructed.
► Microarthropods positively responded to amount of organic matter.
► Based on the result, potential carrying capacity of natural organic soil was estimated.
► Field abundances of the animals were less than the estimated carrying capacity.