Adjustment Techniques of Species Structure on Soil and Water Conservation Forest

Adjustment experiments with 7 methods were done in soil and water conservation forest in western Liaoning. The aims are to solve the problems of pine caterpillars and pure forest of Chinese Pine are too larger. The methods are corridor method, patches method, method of open ground in forest, method of ravine in forest, method of closing the land for reforestation, method of reforestation with plane and method of planting trees into mixed stand. 14 species were selected to adjustment of species structure in soil and water conservation forest based on the abilities of water utilization of tree species and growth situation. 3 adjustment patterns of species structure of soil and water conservation forest are set up based on experiment and matching species with the site. After pure forest of Chinese Pine were adjusted Pine caterpillars no more occurred with higher amount, and abilities of soil and water conservation grew, and tree growth increased, economic and social benefit were double than before. Now, there are 3 stands after adjusted, the first one is soil and water conservation forest with ecological benefit on poor condition, the second one is soil and water conservation forest with ecological and economic benefit in medium condition, the last one is soil and water conservation forest with timber benefit on good condition.