毛乌素沙地樟子松造林效果对土壤盐渍化程度的响应

为探讨毛乌素沙地樟子松造林效果对土壤盐渍化程度的响应规律和机制,分析其造林效果指标、生理特征、生物量分配格局、土壤盐渍化程度的相互关系。结果表明：随着土壤盐渍化程度的加重，全盐、Na+、Cl-含量升高而含水率下降；净光合速率、水分利用效率与全盐、Na+、Cl-含量呈负相关，与造林保存率、林木生长量呈正相关。同时，随着土壤盐渍化程度的加重，种群将更多的生物量分配于根系的生长发育。由此可见：随着土壤盐渍化程度的加重，土壤含水率、净光合速率、水分利用效率以及地上生物量分配比例下降，从而导致樟子松存活与生长能力削弱。因此，提高盐渍化地段造林效果必须从降低土壤盐含量、改善土壤水分状况入手。

Afforestation Effect of Pinus sylvestris var. monglica on Soil Salinity Degree in Mu Us Sandy Land

To explore the afforestation effect of Pinus sylvestris var. monglica plantation on the response regularity and mechanism of soil salinization degree, we analyzed the physiological and ecological characteristics, the afforestation effect index and soil salinization degree of relationship. The results showed that, as soil salinization degree aggravating, the salt, Na+ and Cl- content increased and the moisture content decreased; Net photosynthetic rate and water use efficiency had negative correlation with total salt, content of Na+, Cl-, while afforestation survival rate, the tree growth were positively correlated. At the same time, along with the soil salinization degree aggravating, the population would be more biomass allocation to root growth and development. Thus, as the soil salinization degree aggravating, soil moisture content, net photosynthetic rate and water use efficiency and biomass allocation proportion dropped on the ground, thereby resulting in impaired the ability of mongolica to survive and grow. Therefore, we must improve the effect of afforestation of salinization area from the lower soil salt content, improve soil moisture conditions.