宁夏干旱风沙区降雨量与土壤水分对造林成活率的影响研究

Effects of Precipitation and Soil Moisture on Survival Rate of Forestation of Desert Region in Ningxia

宁夏干旱风沙区降雨量、土壤含水量对苗木成活率的影响研究表明,降雨量对土壤含水量的贡献可用对数曲线模拟,小于5.1mm的降雨量属无效降雨,不会增加土壤含水量,土壤含水量低于1.7%时所有造林树种均无法成活,土壤含水量大于12.0%时才能保证所有树种成活率都达到85%以上。在此基础上分析了降雨量与植苗造林成活率的相关性,在多年春季平均土壤含水量6.0%的基础上,降雨量高于30.4mm才能保证主要树种的造林成活率都达到85%以上。

Study on the effects of precipitation and soil moisture on survival rate of forestation of desert region in Ningxia was carried out. The results showed that contribution of precipitation to soil moisture could be simulated by a Logarithmic Curve,and the precipitation less than 5.1 mm was noneffective as it could not increase the soil moisture. All species of forestation could not survive when soil moisture content ≤ 1.7% ,but the survival rate reached 85% when soil moisture content ≥ 12.0%.Then the correlation of precipitation and survival rate of forestation was analyzed. Based on the average spring soil moisture content of 6.0%, the survival rate of primary forestation species could reach 85% when precipitation ≥30.4 mm.