摘要
垂穗披碱草(Elymus nutans Griseb.)为多年生禾本科牧草,其野生型常见于青藏高原各个区域,因其具有抗旱、抗寒、耐盐碱等优点,成为高海拔地区优选种植牧草品种之一。但是由于垂穗披碱草的种植方法和施肥技术手段不统一,造成其生产-生态功能难以准确评估。鉴于此,本研究在西藏那曲设置了N0(不施肥)、N1(16 g/m^2)、N2(32 g/m^2)3个氮水平和P0(不施磷)、P1(7 g/m^2)和P2(14 g/m^2)3个磷水平的垂穗披碱草人工草地随机交互施肥实验,对垂穗披碱草人工草地生产性能(地上生物量、地下生物量)与生态功能(生态系统呼吸、生态系统净交换量、单位产量的碳排放量)等特征进行了初步研究。结果显示,氮添加对垂穗披碱草地上生物量变化无显著影响,而磷添加提高披碱草人工草地的地上生物量,其中P1和P2处理提高地上生物量的差异不显著。另外还发现,氮磷添加对单位产量的碳排放量的影响具有交互作用,在氮添加条件下添加磷显著降低单位产量的碳排放量,分别为65%、66%、68%、70%,单独施用磷肥时(N0P1、N0P2)同样也能降低单位生产的碳排放量。因此,施磷肥不但能有效提高垂穗披碱草人工草地的产量,而且可以防止土壤有机碳的损失,在施用磷肥时配合氮肥添加能更有效地减少碳排放量。
Elymus nutans Griseb.is a perennial grass and its’wild type is widely distributed in many areas of theQinghai-Tibet Plateau.It has become one of the preferred forage species for planting in high altitude areas be-cause of its advantages on the high ecological adaptability such as drought,cold,and salt-alkali resistance.How-ever,it is difficult to accurately evaluate its production-ecological function due to the inconsistent of plantingmethods and fertilization techniques of Elymus nutans.Therefore,a random interactive fertilization experimentwas designed with 3 nitrogen levels(N0:0 g/m^2,N1:16 g/m^2,N2:32 g/m^2)and 3 phosphorus levels(P0:0 g/m^2,P1:7 g/m^2,P2:14 g/m^2)on artificial grassland of Elymus nutans Griseb.in Nagqu,Tibet,and its production perfor-mance(aboveground biomass and underground biomass)and ecological function(ecosystem respiration,net eco-system carbon exchange,and carbon emissions per unit of production)were evaluated.Nitrogen addition had nosignificant influence on the aboveground biomass.Phosphorus addition can significantly increased abovegroundbiomass,but there were no significant difference in improving above-ground biomass between P1 and P2.In ad-dition,Addition of both nitrogen and phosphorus has interactive effects on carbon emissions per unit of produc-tion.Adding phosphorus under the condition of Nitrogen addition significantly reduced carbon emissions per unitof production about 65%,66%,68%,70%compared with N0P0,respectively,and carbon emissions per unit ofproduction was also significantly reduced about 42%and 47%when phosphate was added alone(N0P1,N0P2).In conclusion,the addition of phosphate fertilizer not only improve the yield of artificial grassland of Elymus nutans Griseb.,but also prevent organic carbon loss from soil.However,phosphate fertilizer combining with nitro-gen addition can more effectively reduce carbon emissions.
作者
仁增旺姆
姜丽丽
汪诗平
贾书刚
Renzneg-Wangmu;JIANG Lili;WANG Shiping;JIA Shugang(Key Laboratory of Alpine Ecology,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy Science,Beijing 100093,China;Guangxi Geographical Indication Crops Research Center of Big Data Mining and Experimental Engineering Technology/Key Laboratory of Environment Change and Resources Use in Beibu Gulf,Nanning 530001,China)
出处
《高原科学研究》
CSCD
2020年第3期55-61,共7页
Plateau Science Research
基金
国家自然基金委面上项目(31672474,31872994)
科技部重点研发项目(2016YFC0501802)
中科院先导(A)项目(XDA20050104)
第二次青藏高原综合科学考察研究项目(2019QZKK0302)。
关键词
净碳交换
碳排放
青藏高原
施肥
垂穗披碱
net ecosystem carbon exchange
carbon emission
Qianhai-Tibetan plateau
fertilization
Elymus nutans Griseb
