Abstract:
Objective The hydrological effects of litter layer and soil layer of Larix kaempferi plantation under different management models in subtropical regions were studied and compared, and the correlation between hydrological performance of the two was explored to provide scientific basis for regional forest hydrological cycle and forest health management.
Method Taking three typical management models of Larix kaempferi plantation (Larix kaempferi-Sassafras tzumu mixed management model, Larix kaempferi-Liriodendron chinense mixed management model and Larix kaempferi pure forest management model) in Changlinggang State-Owned Forest Farm of Jianshi County as the research objects, and the hydrological effects of litter layer and soil layer were studied by means of sample plot observation method, indoor immersion method, cutting ring method and double ring method, and the regression analysis and bivariate correlation analysis were used to fit and analyze the hydrological effects.
Result (1) There were significant differences in the stratification changes of litter thickness and volume under different management models (P < 0.05); the thickness and volume of semi-decomposed layer in mixed forest management model were significantly higher than those in un-decomposed layer, but the opposite was true in pure forest management mode. (2) The change law of water holding capacity and water absorption rate of litter with soaking time in different management models was basically consistent. There was a logarithmic regression relationship between litter water holding capacity and soaking time, and a power function regression relationship between litter water absorption rate and soaking time. (3) The soil physical properties and infiltration performance of mixed forest were better than that of pure forest, and the difference was significant (P < 0.05); the relationship between soil infiltration rate and infiltration time was power function regression. (4) There was a certain correlation between the hydrological effects of litter layer and soil layer in different management models. Except for soil bulk density, soil hydrological indexes were positively correlated with hydrological indexes of semi-decomposed layer of litter, and negatively correlated with hydrological indexes of un-decomposed layer of litter; maximum soil water holding capacity, total porosity, initial infiltration rate, steady infiltration rate were positively correlated with thickness of litter, maximum water holding capacity and maximum water absorption rate of semi-decomposed layer.
Conclusion Generally, the hydrological properties of litter layer and soil layer of mixed management model were better than that of pure forest management model. It is suggested that the influence of tree species composition and configuration mode should be fully considered in forest management, and the near-natural broadleaved transformation of pure coniferous forest should be accelerated to strengthen the hydrological function and healthy management of regional forest.