为进一步探明陕西省榆林市樟子松人工林的土壤养分变化特征,以5年生樟子松(Pinus sylvestris L. var. mongolica Litv.)纯林和5年生樟子松-胡枝子(Lespedeza bicolor Turcz.)混交林为研究对象,分析土壤有机质、硝态氮、有效磷、速效钾...为进一步探明陕西省榆林市樟子松人工林的土壤养分变化特征,以5年生樟子松(Pinus sylvestris L. var. mongolica Litv.)纯林和5年生樟子松-胡枝子(Lespedeza bicolor Turcz.)混交林为研究对象,分析土壤有机质、硝态氮、有效磷、速效钾等理化指标以及土壤酶活性的变化特征。结果表明,樟子松纯林和樟子松-胡枝子混交林土壤有机质、有效磷和速效钾含量整体上均随着土层深度的增加呈下降趋势,全磷含量均随着土层深度的增加呈先升高后降低的趋势,硝态氮含量则均随着土壤深度的增加而增加,5个指标均表现为樟子松-胡枝子混交林高于樟子松纯林,且樟子松-胡枝子混交林各层土壤有效磷含量均显著高于樟子松纯林(P<0.05);樟子松纯林和樟子松-胡枝子混交林土壤含水率各土层间差异均不显著,樟子松-胡枝子混交林5~15 cm土层土壤含水率含量显著高于樟子松纯林(P<0.05);樟子松纯林和樟子松-胡枝子混交林土壤碱性磷酸酶活性、过氧化氢酶活性、脲酶活性均随着土层深度的增加而降低,且樟子松-胡枝子混交林过氧化氢酶活性和脲酶活性在各土层均显著高于樟子松纯林(P<0.05)。展开更多
The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distin...The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distinguished with Tullgren and Baermann methods under three Pinus sylvestris var. mongolica Litv. plantations in Zhanggutai sandy land, China. In addition, soil N mineralization rate was also measured with PVC closed-top tube in situ incubation method. The soil animals collected during growing season belonged to 13 orders, 5 groups, 4 phyla, whose average density was 86 249.17 individuals·m^(-2). There were significant differences in soil animal species, densities, diversities and evenness among three plantations. Permanent grazing resulted in decrease of soil animal species and diversity. The average ammonification, nitrification and mineralization rates were 0.48 g·m^(-2)·a^(-1), 3.68 g·m^(-2)·a^(-1) and 4.16 g·m^(-2)·a^(-1), respectively. The ammonification rate in near-mature forest was higher than that in middle-age forests, while the order of nitrification and net mineralization rates was: middle-age forest without grazing < middle-age forest with grazing < near-mature forest with grazing (P<0.05). Soil N mineralization rate increased with soil animal amounts, but no significant relationship with diversity. The contribution of soil animals to N mineralization was different for different ecosystems due to influences of complex factors including grazing, soil characteristics, the quality and amount of litter on N mineralization.展开更多
文摘为进一步探明陕西省榆林市樟子松人工林的土壤养分变化特征,以5年生樟子松(Pinus sylvestris L. var. mongolica Litv.)纯林和5年生樟子松-胡枝子(Lespedeza bicolor Turcz.)混交林为研究对象,分析土壤有机质、硝态氮、有效磷、速效钾等理化指标以及土壤酶活性的变化特征。结果表明,樟子松纯林和樟子松-胡枝子混交林土壤有机质、有效磷和速效钾含量整体上均随着土层深度的增加呈下降趋势,全磷含量均随着土层深度的增加呈先升高后降低的趋势,硝态氮含量则均随着土壤深度的增加而增加,5个指标均表现为樟子松-胡枝子混交林高于樟子松纯林,且樟子松-胡枝子混交林各层土壤有效磷含量均显著高于樟子松纯林(P<0.05);樟子松纯林和樟子松-胡枝子混交林土壤含水率各土层间差异均不显著,樟子松-胡枝子混交林5~15 cm土层土壤含水率含量显著高于樟子松纯林(P<0.05);樟子松纯林和樟子松-胡枝子混交林土壤碱性磷酸酶活性、过氧化氢酶活性、脲酶活性均随着土层深度的增加而降低,且樟子松-胡枝子混交林过氧化氢酶活性和脲酶活性在各土层均显著高于樟子松纯林(P<0.05)。
基金This research was supported by National Natural Science Foundation of China (30471377 & 30600473)the National Programs for Science and Technology Development of China (No. 2005BA517A03).
文摘The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distinguished with Tullgren and Baermann methods under three Pinus sylvestris var. mongolica Litv. plantations in Zhanggutai sandy land, China. In addition, soil N mineralization rate was also measured with PVC closed-top tube in situ incubation method. The soil animals collected during growing season belonged to 13 orders, 5 groups, 4 phyla, whose average density was 86 249.17 individuals·m^(-2). There were significant differences in soil animal species, densities, diversities and evenness among three plantations. Permanent grazing resulted in decrease of soil animal species and diversity. The average ammonification, nitrification and mineralization rates were 0.48 g·m^(-2)·a^(-1), 3.68 g·m^(-2)·a^(-1) and 4.16 g·m^(-2)·a^(-1), respectively. The ammonification rate in near-mature forest was higher than that in middle-age forests, while the order of nitrification and net mineralization rates was: middle-age forest without grazing < middle-age forest with grazing < near-mature forest with grazing (P<0.05). Soil N mineralization rate increased with soil animal amounts, but no significant relationship with diversity. The contribution of soil animals to N mineralization was different for different ecosystems due to influences of complex factors including grazing, soil characteristics, the quality and amount of litter on N mineralization.
