黄土丘陵半干旱区退化刺槐林不同改造方式效果分析

Effects Different Improvement Measures of Degradated Robinia pseudoacacia in Semi-arid Loess Hilly Region

采用野外典型抽样调查和室内分析测定的方法,在黄土丘陵半干旱区-安塞水土保持综合试验站研究了退化刺槐林经萌蘖更新和重造侧柏林改造后林地土壤水分含量、乔木根系生物量和生物多样性指标的差异。结果表明:萌蘖更新林地内的土壤水分含量和生物多样性指数均高于重造侧柏林地;不同改造方式下整个土层内根系生物量的差异较大,根系生物量最大的是重造侧柏林地,为17.59 g,最小的是退化刺槐林,为16.59 g。萌蘖刺槐林与退化刺槐林相比,土壤水分含量和生物多样性指数变化不大,但林内乔木种类较退化刺槐林内丰富。因此利用间伐萌蘖方式对退化刺槐林改造是可行的。

With the methods of representative field sampling investigation and laboratory analysis, this paper studied the differences of soil water content in forestland, the biomass of root system of tree and the biodiversity under the （Plantycladas oriental degradated Robinia is forest） at semi-arid pseudoacacia by loess hilly region. root-sprout regeneration and reforestation The results showed that the soil moisture and biodiversity index of root-sprout regenerated forest were better than reforestated P. orientalis forest. The root biomass in all soil layers made a great difference under different reformative ways, with the high- est root biomass of 17.59 g in reforestated P. orientalis forest and the lowest root biomass of 16.59 g in degradated R. pseudoacacia. There were little changes in the soil moisture and biodiversity index between root-sprout regenerated forest and degradated R. pseudoacacia forest, but the tree species in root-sprout regenerated forest were much richer than those in degradated R. pseudoacacia forest. Therefore, rootsprout regeneration is a feasible way of reforming degradated R. pseudoacacia forest.