不同强度平茬对柠条生长及养分归还的影响  

Effects of Different Intensities of Thinning on the Growth and Nutrient Return of Caragana korshinskii

作　　者：李金山 马旭君 吴晶 曲浩 程小云 李丽丽 王新源 LI Jin-shan;MA Xu-jun;WU Jing;QU Hao;CHENG Xiao-yun;LI Li-li;WANG Xin-yuan(Grassland Workstation of Liangzhou District,Wuwei Gansu 733000,P.R.China;Urat Desert-grassland Research Station,Northwest Institute of Eco-environment and Resources,Chinese Academy of Sciences,Lanzhou Gansu 730000,P.R.China;Forestry and Grassland Bureau of Urat Rear County,Bayannur Inner Mongolia 015543,P.R.China;Gansu Monitoring Center for Ecological Resources,Lanzhou Gansu 730020,P.R.China;College of Earth Science and Engineering,West Yunnan University of Applied Sciences,Dali Yunnan 671006,P.R.China)

机构地区：[1]武威市凉州区草原工作站,甘肃武威733000 [2]中国科学院西北生态环境资源研究院乌拉特荒漠草原研究站,甘肃兰州730000 [3]乌拉特后旗林业和草原局,内蒙古巴彦淖尔015543 [4]甘肃省生态资源监测中心,甘肃兰州730020 [5]滇西应用技术大学地球科学与工程学院,云南大理671006

出　　处：《西部林业科学》2023年第1期57-63,共7页Journal of West China Forestry Science

基　　金：国家重点研发计划项目(2016YFC0500506);国家自然科学基金(41877540);内蒙古自治区乌拉特后旗巴音温都尔沙漠沙化土地封禁保护补助试点项目(蒙林规-2015-182)。

摘　　要：为柠条平茬复壮提供依据,对乌拉特荒漠草原6龄株柠条进行1/3、1/2和100%(刈割)3种不同高度平茬处理,测定其生长特征指标(高度、盖度、新生枝数量、新生枝含水量与鲜重),并将其平茬下来的鲜枝叶装入网袋内,以监测其养分归还能力。结果显示:(1)植株生长方面,1/3和1/2高度的平茬未对柠条的生长状态产生负面影响,而其盖度在短期内得到显著提升,其新生枝在以不牺牲含水量为前提的情况下数量显著增加,刈割则不能使其生长获益,属于过度平茬。(2)土壤养分方面,1/3平茬对土壤氮和磷的归还力显著高于对照和另外两种处理,而刈割是增加土壤速效钾含量的最佳措施。研究结果提示,在荒漠草原退化草地恢复的实际工作中,对柠条进行1/3高度平茬最有利于其进行二次萌蘖与更新复壮,并可以最大程度的发挥其养分归还效应。Caragana korshinskii is one of the most important artificial vegetation types for soil and water conservation and sand fixation in the desert steppe in northwest China.However,after a certain age of growth,the ecological and economic benefits of C.korshinskii will be affected by the increase degree of lignification and the decline of growth force.The compensatory growth effect produced by the thinning is the most effective means to solve this problem.We carried out Three different heights of thinning treatments(1/3,1/2 and 100%of plant height)on the 6-year-old Caragana korshinskii were conducted in the Urat desert steppe,and measured its growth characteristics(height,coverage,number of new shoots and their water contents).Fresh branches and leaves(green litterfall)from the different thinning treatments were put into mesh bags to monitor their nutrient return ability.The results showed that:after 4 years,the 1/3 and 1/2 height of the thinning did not have a negative impact on the high growth of C.korshinskii,but its coverage was significantly improved in a short period of time,and the number of new shoots increased significantly without losing water content,while the 100%treatment does not benefit its growth,which was identified as excessive thinning.The 1/3 thinning treatment had significantly higher returning ability to soil nitrogen and phosphorus than the control and the other two thinning treatments,while 100%thinning treatment is the best measure to increase soil available potassium content.Therefore,we concluded that in the actual work of the restoration of the degraded grassland in the desert steppe,the 1/3 height thinning of C.korshinskii is most conducive to its secondary tillering and regeneration,and can maximize its nutrient return effect.

关 键 词：柠条 平茬 荒漠草原 新生枝 土壤养分 

分 类 号：S793.3[农业科学—林木遗传育种]