农田防护林对耕地土壤侵蚀速率和空间分布格局的影响  

Effects of shelter forest on rates and spatial patterns of soil erosion in a cultivated land

作　　者：伍佐 苏正安[1] 王勇 张信宝[1] 周涛[1,3] 王晓艺 何周窈 刘翊涵 WU Zuo;SU Zheng'an;WANG Yong;ZHANG Xinbao;ZHOU Tao;WANG Xiaoyi;HE Zhouyao;LIU Yihan(Key Laboratory of Mountain Hazards and Earth Surface Processes/Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,Sichuan,China;College of Water Conservancy and Hydropower Engineering,Sichuan Agricultural University,Ya’an 625014,Sichuan,China;University of Chinese Academy of Science,Beijing 100049,China;Forestry College,Sichuan Agricultural University,Chengdu 611130,Sichuan,China;College of Geography and Resources Science,Sichuan Normal University,Chengdu 610101,Sichuan,China)

机构地区：[1]中国科学院、水利部成都山地灾害与环境研究所/中国科学院山地灾害与地表过程重点实验室,四川成都610041 [2]四川农业大学水利水电学院,四川雅安625014 [3]中国科学院大学,北京100049 [4]四川农业大学林学院,四川成都611130 [5]四川师范大学地理与资源科学学院,四川成都610101

出　　处：《草业科学》2020年第7期1218-1226,共9页Pratacultural Science

基　　金：水体污染控制与治理科技重大专项(2017ZX07101-001);四川省科技计划(2018JY0034、2018SZDZX0034)。

摘　　要：利用137Cs示踪技术对张家口坝上地区农田防护林对农耕地土壤侵蚀速率及其空间分布格局的影响进行了初步研究。结果表明:1)农耕地土壤剖面137Cs呈均匀分布,防护林土壤剖面137Cs呈指数型分布;2)不同土地利用类型下土壤137Cs面积活度表现为沿主风向的防护林[(3148.38±228.91)Bq·m^-2]>垂直于主风向的防护林[(2548.09±202.56)Bq·m^-2]>农耕地[(1687.43±174.99)Bq·m^-2],土壤侵蚀速率表现为农耕地[(4446.04±208.68)t·(km^2·a)^-1]>垂直于主风向的防护林[(2514.56±181.08)t·(km^2·a)^-1]>沿主风向的防护林[(1357.32±301.56)t·(km^2·a)^-1];3)距离防护林越近的区域,农耕地土壤137Cs面积活度越高,土壤侵蚀速率越小,而越靠近农耕地中心部位,土壤137Cs面积活度越低,土壤侵蚀模数越高,这表明防护林成林后在减弱耕地风沙侵蚀方面发挥了重要作用;4)垂直于主风向的防护林土壤137Cs面积活度总体呈由西南向东北降低的趋势,即越靠近沿主风向的防护林,土壤137Cs面积活度越高,土壤侵蚀模数越低;5)沿主风向的防护林土壤137Cs面积活度显著高于垂直于主风向的防护林,这表明沿主风向防护林的土壤侵蚀速率显著低于垂直于主风向的防护林。综上可知,农田防护林对我国北方农耕地土壤侵蚀空间分布格局具有显著影响,能够显著减弱农耕地风力侵蚀速率。The 137Cs tracer technique was used to study the effects of shelter forests on rates and spatial patterns of soil erosion in a cultivated land(CL)in the Bashang Region of Zhangjiakou City.The results showed that 137Cs was uniformly distributed in the soil profile of CL,and an exponentially decreasing trend of 137Cs concentration from the top to bottom layer of soil profile was observed in a shelter forest land(SFL).137Cs inventories in SFL along the primary wind direction(ASFL),SFL perpendicular to the primary wind direction(PSFL),and CL were estimated to be 3148.38±228.91 Bq·m^-2,2548.09±202.56 Bq·m^-2 and 1687.43±174.99 Bq·m^-2,respectively.137Cs inventories in ASFL were the highest,while those in CL were the lowest.Soil erosion rates in CL,PSFL,and ASFL were estimated to be 4446.04±208.68 t·(km^2·a)^-1,2514.56±181.08 t·(km^2·a)^-1,and 1357.32±301.56 t·(km^2·a)^-1,respectively.Meanwhile,the effects of shelter forest on rates and spatial patterns of soil erosion in CL were evident.In CL,137Cs inventories exhibited a decreasing trend and soil erosion rates exhibited an increasing trend as the distance from FSL increased,indicating that shelter belts play important roles in protecting the CL from wind erosion because the surrounding shelter forest is mature.Simultaneously,as distance from ASFL decreased,137Cs inventories in PSFL exhibited an increasing trend.Additionally,137Cs inventories in ASFL were obviously higher than those in PSFL,indicating that PSFL experienced greater soil loss than did ASFL.These results indicate that the surrounding shelter belts play a critical role in altering the spatial patterns of soil erosion and reducing wind erosion rates in the CL in northern China.

关 键 词：137Cs 土壤侵蚀速率 空间格局 农田防护林 农耕地 

分 类 号：S157.1[农业科学—土壤学]