摘要
为评价红壤区林下侵蚀劣地恢复措施的有效性,以江西宁都典型马尾松退化林地为对象,设置7个处理:无恢复措施(CT)、鱼鳞坑+乔草(FG)、鱼鳞坑+乔灌(FS)、鱼鳞坑+乔灌草(FGS)、小水平沟+乔草(FGP)、小水平沟+乔灌(FSP)、小水平沟+乔灌草(FGSP),利用^(7)Be示踪技术评价了林下劣地次降雨事件土壤侵蚀及碳氮养分流失对不同恢复措施的响应。结果表明,试验4年后,各恢复措施土壤^(7)Be面积活度显著高于CT,面积活度残留率为-6.84%~-33.13%,土壤侵蚀速率(RBe)为4.43~24.04 t·hm^(-2)·event^(-1),各恢复措施减蚀效率为21.19%~85.49%,其中FGSP和FGS减蚀量最大(分别为85.49%和83.81%);与CT相比,各恢复措施土壤有机碳(SOC)、全氮(TN)、速效氮(AN)含量的增幅为25.10%~65.71%、9.79%~46.85%、-30.68%~1.29%;鱼鳞坑和小水平沟区组下,乔灌草复合植被措施(FGSP和FGS)可显著减少土壤碳氮养分流失,但两种工程措施无显著差异。简单相关和逐步回归分析表明,土壤^(7)Be面积活度与SOC、TN、AN含量呈极显著正相关(P<0.01),RBe和植被盖度(VC)解释了SOC流失94.7%的变异,RBe、TN和VC共同解释了TN流失98.3%的变异,而RBe解释了AN流失85.6%的变异,说明SOC、TN、AN组分与^(7)Be同一物理运移,土壤碳氮养分流失受植被-土壤-水土过程耦合互作影响。综上,7 Be可有效评价不同恢复措施下林下侵蚀劣地短期土壤侵蚀及养分流失状况,实施恢复措施4年后,草灌乔复合植被措施相对于工程措施对降低土壤侵蚀及碳氮养分流失作用更显著。本研究结果为林下侵蚀劣地恢复和生态效益评估提供了科学依据。
To evaluate the effectiveness of soil restoration measures in erosion-degraded forestlands in red soil region of South China,a typical erosion-degraded Pinus massoniana forestland was selected,which located in Ningdu County,Jiangxi province.Seven treatments were set up in this trial:no restoration measures(CT),fish scale pit+tree-grass(FG),fish scale pit+tree-shrubs(FS),fish scale pit+tree-shrubs-grass(FGS),small horizontal ditch+tree-grass(FGP),small horizontal ditch+tree-shrubs(FSP),small horizontal ditch+tree-shrubs-grass(FGSP).The response of soil erosion and nutrient loss to different restoration measures in the erosion-degraded forestlands was evaluated using the^(7)Be tracing technique.Results showed that the^(7)Be inventory residual percentage under different restoration measures was-6.84%to-33.13%.Soil erosion rate under different restoration measures ranged from 4.43 to 24.04 t·hm^(-2)·event^(-1).The sediment reduction rate was 21.19%-85.49%compared with the CT,and the maximum were 85.49%and 83.81%under FGSP and FGS respectively.Compared with CT,the percentages of increment of soil organic carbon(SOC),total nitrogen(TN),available nitrogen(AN)in each restoration measures were 25.10%-65.71%,9.79%-46.85%,-30.68%-1.29%,respectively.Under two engineering measures,integrated vegetation measures(i.e.FGSP and FGS)of tree-shrubs-grass significantly reduced soil carbon and nitrogen loss,but there was no significant difference between the two engineering measures.The Pearson correlation and stepwise regression analysis suggested that^(7)Be was significantly and positively correlated with SOC,TN and AN content(P<0.01).RBe and VC explained 94.7%of variation of SOC loss;RBe,TN and VC explained 98.3%of variation of TN loss;and RBe explained 85.6%of variation of AN loss,which indicated that that SOC,TN and AN were physically transported with^(7)Be during soil erosion process,and soil carbon and nitrogen nutrient loss was influenced by coupling interactions of vegetation-soil-soil and water processes.^(7)Be allowed effective evaluation of short-term soil erosion and nutrient loss by different restoration measures.After 4 years of implementing restoration measures,the effect of integrated vegetation measures with tree-shrubs-grass on reducing soil erosion,carbon and nitrogen loss was more significant than that of soil conservation engineering measures.The results of this study provided scientific basis for assessment of ecological benefits and restoration management of erosion-degraded forestlands.
作者
陆朝阳
王洪雨
薛婷婷
刘文祥
陈晓光
于寒青
LU Zhaoyang;WANG Hongyu;XUE Tingting;LIU Wenxiang;CHEN Xiaoguang;YU Hanqing(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081;Chongqing Branch Institute,Changjiang River Scientific Research Institute,Chongqing 400026)
出处
《核农学报》
CAS
CSCD
北大核心
2023年第9期1833-1842,共10页
Journal of Nuclear Agricultural Sciences
基金
国家重点研发计划课题(2017YFC0505402)。
