Study On The Interaction Of Litter And Surface Soil In Secondary Oak Forest, Pine Forest Of The Zijin Mountain

Leaf-litters layer and soil layer, as an important part of forest ecosystem, have important ecological functions, such as regulating runoff, keeping water and soil conservation, water conservation, and so on.This paper based on Nanjing Zijin Mountain secondary oak forest, pine forest(Pinus massoniana) leaf-litters decomposition rate and nutrient release characteristics and soil physical and chemical properties and earthworm number of analysis and study in a secondary oak forest and Pine forest in two different forest leaf-litters and soil interaction, the main results are as follows:(1)Secondary oak forest, Pine forest leaf-litters leaf-litters quality in the presence of significant difference, secondary oak forests deadwood defoliation layer N, P content was higher than that of Pine forest. And pine leaf-litters layer of C/N and C/P is greater than the secondary oak forest, significant differences(P < 0.01). The weight loss rate of dry matter after decomposition of 1a was less than that of secondary oak forest, and the difference was significant(P < 0.05). The leaf-litters decomposition of the secondary oak forest and pine forest showed obvious seasonal characteristics.(2)The secondary oak forest leaf-litters and the pine leaf-litters were placed in a secondary oak forest and Pine forest, after the decomposition of 1a, the rate of weight loss were significant difference(P < 0.01). Two types of leaf-litters were in the secondary oak forest in weightlessness rate is higher, the faster decomposition rate. According to the Olson exponential regression equation, the decomposition half-life and 95% time of secondary oak forest leaf-litters decomposition in secondary oak forest and pine forest were estimated. There were significant differences in the leaf-litters of the secondary oak forest and pine forest in the soil environment(P < 0.01) in two different forest types.(3)After the decomposition of 1a, placed in secondary oak forest, pine forest, secondary oak forest leaf-litters N and P residual rate and placed in secondary oak forest, Pine forest of Pinus massoniana leaf-litters N, P residual rate, fully shows that secondary oak forest on the decomposition environment on leaf-litters nutrient release has a role in promoting, show different community types of forest soil under environmental conditions on leaf-litters decomposition has a more significant impact.(4)Different types of forest leaf-litters on soil bulk density, capillary porosity, water holding capacity and capillary moisture influence. Secondary oak forest soil bulk density in leaf-litters than Pinus massoniana low, capillary porosity is bigger, better water holding capacity. So the leaf-litters of broad-leaved tree is more conducive to the improvement of soil structure of conifer.(5)Leaf-litters decomposition and nutrient release in different stand types had effects onsoil nutrient content and pH. Different forest leaf-litters layer N content and decomposition of soil total N had a significant impact; P elements in soil in the ecological system flow is strong,and in summer content reached the maximum; two leaf-litters fall layer on the content of soil total P effect was not significant(P > 0.05); secondary oak forest and Pine forest soil available phosphorus and two stand deadwood defoliation layer P content changes similar to that leaf-litters decomposition for soil available phosphorus content has significant effect; different forest leaf-litters decomposition effect on the concentration of soil available K significantly.Secondary oak forest and pine forest soil pH value had no obvious seasonal variation, the average 5.43 and 4.62, secondary oak forest is acidic, Pine forest is highly acidic, secondary oak forest leaf-litters leaves layer decomposition is beneficial to increase soil pH value.(6)Leaf-litters nutrient content and soil nutrient content of a certain correlation. Secondary oak forest, Pine forest leaf-litters layer in N content and soil total N showed significant correlation(P < 0. 05) and secondary oak forest correlation strong; in the secondary oak forest and Pine forest leaf-litters layer P content and soil available P also showed significant correlation(P < 0.05), and is related to the degree of near; two stand the deadwood defoliation layer P content and soil total P no significant correlation; secondary oak forest and Pine forest leaf-litters layer K and soil available K low-grade related.(7)The number of earthworms in the surface soil of different leaf-litters has great difference. Secondary oak forest soil earthworm numbers mean 87/m2, and the number of earthworms in the soil of Pine forest averaged 33/m2, which was significantly lower than that of the number of earthworm in secondary oak forest soil and leaf-litters,leaf-litters types has significant effect on the number of earthworms in soil.