Comparison analyses of the functional groups of natural enemy of Ancylis sativa (Lepioptera: Tortricidae) in jujube forestry with different managements
Abstract:There are considerable amounts of canopy humus within the crowns of trees in tropical, subtropical and temperate montane moist forests. As an important structural component, the canopy humus provides essential substrates and nutrients for the growth of abundant epiphytes. In this study, the physical and chemical properties, microbial biomass and enzyme activities of humus from both canopy and forest floor were analyzed in a subtropical montane moist evergreen broad-leaved forest in Ailao Mts., Yunnan. The significant differences in the physical and chemical properties and microbial activities were found between the canopy humus and humus from forest floor, due to differences in origins, composition of humus and spatial distribution patterns. The concentration of organic C, total N, total Ca, as well as C/N ratio and cation exchange capacity were significantly higher in canopy humus, whereas higher concentrations of total K and total Mg were observed in the humus from forest floor. There was no significant difference in total P concentration between two humus types. The microbial biomass C and N, respiration rate, as well as activities of sucrase, urease and protease were significantly greater in canopy humus than its terrestrial counterpart. These results indicated that canopy humus belong to a category of organic histosol with high nutrients content and microbial activities, and thus it could play important roles in nutrients cycling, maintenance of species diversity pattern of epiphytes in the montane moist evergreen broad-leaved forest ecosystems.