辽西北防护林对林下土壤理化性状的影响

Effects of Shelterbelt on Soil Physical and Chemical Properties in Northwestern Liaoning Province

以辽西北防护林土壤为研究对象,比较防护林内外土壤水稳性团聚体质量分数、破坏率和有机质质量分数的差异,分析土壤性状变化与林分因子的关系。结果表明,大部分防护林下土壤水稳性团聚体和有机质质量分数增加,团聚体破坏率下降;但也有部分林分土壤性状变化不明显,甚至退化。防护林内外土壤团聚体变化率与树种组成和植被盖度均呈显著正相关(P<0.05),而与林分年龄和地表生物量的相关性不显著(P>0.05);土壤有机质变化率与树种组成、植被盖度和生物量均呈显著正相关(P<0.05),而与林分年龄无显著关系(P>0.05)。说明防护林的树种组成和地表植被对林下土壤理化性状变化影响显著,因此应合理选择树种,保护林下植被,加强抚育管理。

We studied the percentage of aggregate disruption,and soil organic matter content of internal and external shelterbelt（ windbreak and sand-fixation forest,soil and water conservation forest and farmland shelterbelt） in northwestern Liaoning Province,and analyzed the relationships between soil properties and forest factors. The soil water stable aggregate and organic carbon content increased,and the percentage of aggregate disruption decreased in most of shelterbelts,but the soil physical and chemical properties varied little,or even degraded in some shelterbelts. The change rate of water stable aggregate of internal and external forests was significantly correlated with tree species and vegetation coverage（ P0.05）,but was insignificantly correlated with forest age and vegetation biomass（ P0.05）. Furthermore,the change rates of soil organic carbon content of internal and external forests were significantly correlated with tree species,vegetation coverage and biomass（ P0.05）,but the correlation was not significant between the change rate and forest age（ P0.05）. Therefore,there are close relations between variation of soil properties and tree species,and the tree species should be properly selected,the undergrowth vegetation should be well protected,and the tending management should be strengthened.