The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, netprimary pro...The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, netprimary production and their distributions of trunk, bark, branch, leaf and root of 16-year-old stand were analyzed.The regressive equation for the estimation of each organ biomass was established through djmensional analysis.Preferable equation with higher precision was selected. The study results showed that the total biomass of theforest community was 62.023 t/hm2 and net primary production was 5.045 V(hm2. a). which indicates that thecommunity of plantation possesses high bio-productivity.展开更多
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
In order to investigate the effects of afforestation on soil microbial abundance, microbial biomass carbon and enzyme activity in sandy dunes, 20-year-old Pinus sylvestris var. mongolica Litv. （PSM） and Populus simo...In order to investigate the effects of afforestation on soil microbial abundance, microbial biomass carbon and enzyme activity in sandy dunes, 20-year-old Pinus sylvestris var. mongolica Litv. （PSM） and Populus simonii Carri6re （PSC） mature forests were se- lected in Horqin Sandy Land, and mobile dunes was set as a control （CK）. Results show that PSM and PSC plantations can im- prove soil physicochemical properties and significantly increase microbiological activity in mobile dunes. Soil microbial abun- dance, microbial biomass carbon and enzyme activity show an order of PS〉PSM〉CK. Total soil microbial abundance in PSM and PSC was respectively 50.16 and 72.48 times more than that in CK, and the differences were significant among PSM, PSC and CK Soil microbial biomass carbon in PSM and PSC was respectively 23.67 and 33.34 times more than that in CK, and the difference was insignificant between PSM and PSC. Soil enzyme activity, including dehydrogenase （DEH）, peroxidase （PER）, protease （PRO）, urease （URE） and cellobiohydrolase （CEL） in PSM and PSC were respectively 19.00 and 27.54, 4.78 and 9.89, 4.05 and 8.67, 29.93 and 37.46, and 9.66 and 13.42 times of that in CK. R sylvestris and P. simonii can effectively improve soil physico- chemical and microbiological properties in sandy dunes and fix mobile dunes in Horqin Sandy Land. The Cmic：C ratio is an appli- cable indicator to estimate soil stability and soil water availability, and based on an overall consideration of plantation stability and sustainability, R sylvestris is better than R simonii in fixing mobile dunes in sandy land.展开更多
文摘The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, netprimary production and their distributions of trunk, bark, branch, leaf and root of 16-year-old stand were analyzed.The regressive equation for the estimation of each organ biomass was established through djmensional analysis.Preferable equation with higher precision was selected. The study results showed that the total biomass of theforest community was 62.023 t/hm2 and net primary production was 5.045 V(hm2. a). which indicates that thecommunity of plantation possesses high bio-productivity.
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.
基金supported by the National Science and Technology Support Program(2011BAC07B02)Young Scientists Foundation of Chinese Academy of Sciences(CAS)(Y251951001)National Natural Science Foundation of China(41171414and31170413) from Coldand Arid Regions Environmental and Engineering Research Institute,CAS
文摘In order to investigate the effects of afforestation on soil microbial abundance, microbial biomass carbon and enzyme activity in sandy dunes, 20-year-old Pinus sylvestris var. mongolica Litv. （PSM） and Populus simonii Carri6re （PSC） mature forests were se- lected in Horqin Sandy Land, and mobile dunes was set as a control （CK）. Results show that PSM and PSC plantations can im- prove soil physicochemical properties and significantly increase microbiological activity in mobile dunes. Soil microbial abun- dance, microbial biomass carbon and enzyme activity show an order of PS〉PSM〉CK. Total soil microbial abundance in PSM and PSC was respectively 50.16 and 72.48 times more than that in CK, and the differences were significant among PSM, PSC and CK Soil microbial biomass carbon in PSM and PSC was respectively 23.67 and 33.34 times more than that in CK, and the difference was insignificant between PSM and PSC. Soil enzyme activity, including dehydrogenase （DEH）, peroxidase （PER）, protease （PRO）, urease （URE） and cellobiohydrolase （CEL） in PSM and PSC were respectively 19.00 and 27.54, 4.78 and 9.89, 4.05 and 8.67, 29.93 and 37.46, and 9.66 and 13.42 times of that in CK. R sylvestris and P. simonii can effectively improve soil physico- chemical and microbiological properties in sandy dunes and fix mobile dunes in Horqin Sandy Land. The Cmic：C ratio is an appli- cable indicator to estimate soil stability and soil water availability, and based on an overall consideration of plantation stability and sustainability, R sylvestris is better than R simonii in fixing mobile dunes in sandy land.
