在典型红壤丘陵区平均坡度为10°的坡耕地径流小区(2 m×5 m)上进行降雨强度为1.69mm min-1(大雨强)、1.31 mm min-1(中雨强)和0.64 mm min-1(小雨强)的模拟降雨试验,并对模拟降雨过程中泥沙的迁移规律和土壤有机碳的流失富集...在典型红壤丘陵区平均坡度为10°的坡耕地径流小区(2 m×5 m)上进行降雨强度为1.69mm min-1(大雨强)、1.31 mm min-1(中雨强)和0.64 mm min-1(小雨强)的模拟降雨试验,并对模拟降雨过程中泥沙的迁移规律和土壤有机碳的流失富集规律进行了研究。结果表明:侵蚀作用下土壤流失量随着降雨强度的增大而增加,并与径流量呈显著的立方关系,径流量是坡耕地土壤流失的重要影响因素;土壤有机碳流失以泥沙结合态为主,泥沙态有机碳流失量占总有机碳流失量的84%以上,最高达97.6%;泥沙中有机碳富集比随着降雨强度的增大而减小,有机碳的选择性迁移在低强度降雨条件下表现更为明显;中雨强和小雨强下有机碳的富集比与黏粒的富集比分别呈极显著和显著正相关,而大雨强泥沙有机碳富集比与黏粒富集比没有显著的线性关系。雨强是影响泥沙流失和泥沙有机碳迁移的重要因素。展开更多
通过野外微型径流小区模拟降雨试验,对坡面小区尺度水力侵蚀过程中物理运移土壤有机碳的规律进行研究。结果表明:2 m×5 m径流小区持续降雨30 min后,大雨强(1.64 mm min-1)和小雨强(0.58 mm min-1)降雨条件下泥沙携带流失的有机碳...通过野外微型径流小区模拟降雨试验,对坡面小区尺度水力侵蚀过程中物理运移土壤有机碳的规律进行研究。结果表明:2 m×5 m径流小区持续降雨30 min后,大雨强(1.64 mm min-1)和小雨强(0.58 mm min-1)降雨条件下泥沙携带流失的有机碳总量分别为56.09 g和3.18 g,溶解于径流流失的有机碳总量分别为13.55 g和2.81 g。降雨强度和持续时间对有机碳流失的过程特征有显著影响。降雨强度越大,泥沙携带及溶解于径流的有机碳流失速率和总量也越大。大雨强泥沙有机碳富集比在产流发生后的18min内大于1,随后降至1以下。小雨强泥沙有机碳富集比始终小于1。大雨强径流有机碳浓度与径流量呈立方关系,小雨强有机碳流失量随径流量增加呈线性递增趋势;大雨强泥沙有机碳含量与泥沙量之间具有明显的立方关系。展开更多
A preliminary investigation on the characteristics of animals in the soil of Huangshan forests was conducted.Invertebrates included 33 genera in 11 classes and 5 phyla,among which Acarina,Collembola and Nematoda were ...A preliminary investigation on the characteristics of animals in the soil of Huangshan forests was conducted.Invertebrates included 33 genera in 11 classes and 5 phyla,among which Acarina,Collembola and Nematoda were dominant groups,occupied 88.21% of the total samples,and formed the main body of the forest soil animal community.The others included common groups and rare groups,respectively accounting for 5.85% and 5.98%.It is warm and humid in the mid-subtropical region of China,covered with lush vegetation has and with an abundant resource of animals in the soil underneath.Soil animal abundance was affected by a number of factors,among which vegetation and soil types are the main limiting factors.Based on data collected from 4 sample sites the evergreen broad-leaved forest and the conifer-broad leaved mixed forest had the highest average density of soil animals,rearching up to 68.80 and 66.53 104·m-3,respectively,while the artificial coniferous forest had the lowest density,with only 36.43 104·m-3.The vertical distribution of animals in the soil was closely related with the surface accumulation of organic matter and the vertical variation of soil physiochemical characteistics.The results showed the soil animals were mainly distributed in litter and humus layers,and obviously accumulated on of the soil surface and sharply decreased downward.展开更多
文摘在典型红壤丘陵区平均坡度为10°的坡耕地径流小区(2 m×5 m)上进行降雨强度为1.69mm min-1(大雨强)、1.31 mm min-1(中雨强)和0.64 mm min-1(小雨强)的模拟降雨试验,并对模拟降雨过程中泥沙的迁移规律和土壤有机碳的流失富集规律进行了研究。结果表明:侵蚀作用下土壤流失量随着降雨强度的增大而增加,并与径流量呈显著的立方关系,径流量是坡耕地土壤流失的重要影响因素;土壤有机碳流失以泥沙结合态为主,泥沙态有机碳流失量占总有机碳流失量的84%以上,最高达97.6%;泥沙中有机碳富集比随着降雨强度的增大而减小,有机碳的选择性迁移在低强度降雨条件下表现更为明显;中雨强和小雨强下有机碳的富集比与黏粒的富集比分别呈极显著和显著正相关,而大雨强泥沙有机碳富集比与黏粒富集比没有显著的线性关系。雨强是影响泥沙流失和泥沙有机碳迁移的重要因素。
文摘A preliminary investigation on the characteristics of animals in the soil of Huangshan forests was conducted.Invertebrates included 33 genera in 11 classes and 5 phyla,among which Acarina,Collembola and Nematoda were dominant groups,occupied 88.21% of the total samples,and formed the main body of the forest soil animal community.The others included common groups and rare groups,respectively accounting for 5.85% and 5.98%.It is warm and humid in the mid-subtropical region of China,covered with lush vegetation has and with an abundant resource of animals in the soil underneath.Soil animal abundance was affected by a number of factors,among which vegetation and soil types are the main limiting factors.Based on data collected from 4 sample sites the evergreen broad-leaved forest and the conifer-broad leaved mixed forest had the highest average density of soil animals,rearching up to 68.80 and 66.53 104·m-3,respectively,while the artificial coniferous forest had the lowest density,with only 36.43 104·m-3.The vertical distribution of animals in the soil was closely related with the surface accumulation of organic matter and the vertical variation of soil physiochemical characteistics.The results showed the soil animals were mainly distributed in litter and humus layers,and obviously accumulated on of the soil surface and sharply decreased downward.
