Study On Soil Ecological Characteristics After Natural Evergreen Broadleaved Forest Artificial Regeneration In Southern Sichuan Province

This paper systematically studied on the change of soil ecological characteristics which include eco-hydrological benefits of forest litter layer, soil's water conservation, soil fertility feature, change of soil carbon pool, soil fractal feature, and effects of litter on soil fertility under natural evergreen broadleaved forest and three artificial plantations, Sassafras tzumu, Cryptomeria fortunei and Metasequoia glyptostroboides forests, which formed by artificial regeneration of natural evergreen broadleaved forest in southern sichuan province. The results as follows:CD The amount of litter layer was natural evergreen broadleaved forest(25.68 t/hm~2) >Metasequoia glyptostroboides plantation(18.14 t/hm~2)>Sassafras tzumu plantation(9.95 t/hm~2)> Cryptomeria fortunei plantation(1.13 t/hm~2). The natural water content of whole litter layer in natural evergreen broadleaved forest was 3.18, 41.33, 1.53 times of that in Sassafras tzumu, Cryptomeria fortunei and Metasequoia glyptostroboides plantations, respectively. During the process of water holding of litter layer, the water holding capacity and absorption speed of the first 2 h were superior to the rest of time. The equation between the water holding capacity of the litter layer and the immerse time was Q = a ln t + b, the equation between the water absorption speed of the litter layer and the immerse time was V = k f. The maximum water holding capacity, the maximum interception and the modified interception of litter layer were natural evergreen broadleaved forest > Metasequoia glyptostroboides plantation > Sassafras tzumu plantation > Cryptomeria fortunei plantation.â‘¡ The bulk density increase and porosity decrease are the main factors which resulted in the decrease of soil water storage and drainage capacity and infiltration after natural evergreen broadleaved forest artificial regeneration; Among the three artificial plantations, Sassafras tzumu plantation soil had higher water storage and drainage capacity and better infiltration, followed by soils with Metasequoia glyptostroboides plantation and Cryptomeria fortunei plantation; Correlation analysis indicated that the correlation coefficient between the soil organic matter, bulk density, porosity, water storage and drainage capacity and infiltration reached significant level.