Study On The Protective Effects Of Farm-shelter Forest Network In Alluvial Sandy Area Of The Old Yellow River

This study contrasted to analyze the windbreak effect, temperature effect, hydrology effect, soil improvement effect, wind erosion preventive effect and yield-increasing effect of three species farm-shelter forest network which on the alluvial sandy area of the old yellow river of Xiajin County in north Shandong Province, and using the market value method to evaluate the protect effect and yield-increasing effect economic benefit of the farm-shelter forest network. At the same time, according to the local farm-shelter forest network actual need renewal to reform, contrasted to observed the fitting poplar of the farm-shelter forest network in the alluvial sandy area of the old yellow river, the research result indicate:1.Pass the cluster analysis,10 poplar clone can divided into four series, zhonglin-46, L35 and W-141 is category 1, Zhonghe No.1, L-324 and I-69 is category 2, I-107, T66 and NL895 is category 3, the I-214 is alone.L-324 of America black pop-lar and L-35, W-141, I-69 of Euro-American poplar are fit to the farm-shelter forest network of alluvial sandy area of old yellow river in Shandong province.2.The wind speed of three farm-shelter forest network are all low to comparison,and intra-network wind speed as differ as the tree height multiple department. three farm-shelter forest network wind protection efficiency order for : 130m×300m's network>260m×300m's network>300m×400m's network.3. In mid-May, the air temperature of intra and outside network fit for the order is:130m×300m<260m×300m<300m×400m260m×300m's network>300m×400m's network. Under the condition of a sunshine weather,each survey point evaporation from open water surface fit for the proper order is: Comparison>130m×300m's network>260m×300m's network>300m×400m's network. The improvement effect to the evaporation in proper order is:130m×300m's network>260m×300m's network>300m×400m's network.6.The soil moisture of different depth area inside the network of the three species farm-shelter forest network are all higher than comparison. Soil moisture intra-network shows disciplinary with apart from the different tree height multiple of network, this is exactly the opposite with speed of wind in the level distributing intra-network. The effect of adjusting the soil moisture in proper order:130m×300m's network>260m×300m's network>300m×400m's network.7.The farm-shelter forest network can greatly improve the edaphically mechanical...