改造华家岭防护林带的土壤改良效果

Soil Amelioration Effect of Low-efficient Shelterbelts Transformation in Huajialing,Gansu,China

为探讨华家岭低效防护林带改造对土壤的改良效果,在华家岭地区选取生长不良的低效杨树纯林和改造后的云杉纯林、云杉×杨树、云杉×油松、云杉×落叶松混交林5种典型林带类型,对其土壤理化性状进行对比研究。结果表明:(1)云杉纯林及其混交林土壤的平均容重、平均毛管孔隙度、总孔隙度、通气度与杨树纯林的差异显著(p<0.05),经过低效林改造后的云杉纯林及其混交林较杨树纯林的土壤容重有所下降,孔隙度和通气性有所提高。(2)除速效P外,各林型的土壤速效N、速效K、全N、全P、全K和有机质含量随土层深度的增加而降低;云杉纯林及其混交林的土壤有机质含量、速效N、P、K和全量N、P、K养分均高于杨树纯林,pH值低于杨树纯林。(3)云杉纯林及其混交林的有机质含量和全N含量与容重和总孔隙度的相关性较杨树纯林的好,云杉纯林及其混交林对土壤理化性能的改良作用优于杨树纯林。

In order to discuss the effect of low-efficient shelterbelts transformation on soil amelioration in Huajialing. The soil physicochemical properties were studied by choosing low-efficient Populus pure forest which grew badly and Picea asperata pure forest, Picea asperata Populus, Picea asperata Pinzs tabu- laetbrmis and Picea asperata Larix prncipis-rupprechtii which were transformation forest in the district of Huajialing. The results showed that： （1） Differences of soil mean bulk density, capillary porosity, total porosity and venting quality were significant between Picea asperata pure forest and its mixed forests and Pops pure forest. Compared with Poputus pure forest, after low-efficient transformation, the soil bulk density of Picea asperctta pure forest and its mixed forests were decreased to some extent, porosity and vent ability were improved. （2） The contents of soil available N, available K, total N, total P, total K and organic matter in forest types all decreased gradually with the increasing of soil depth except the available P. And the organic matter, available N, P, K and total N, P, K of Picea asperata pure forest and its mixed for ests were higher than Populus pure forest. PH of Populus pure forest was higher than Picea asperata pure forest and its mixed forests. （3） The correlations between soil organic matter, total N and soil bulk density, total porosity of Picea asperata pure forest and its mixed forests were better than Popdus pure forest. Amelioration effects of Picea asperata pure forest and its mixed forests on soil physicochemical properties were superior to Populus pure forest.