To better understand the ecological and economic benefits of short-term grazing exclusion on the aboveground net primary productivity(ANPP)of alpine pastures,we conducted annual multi-site transect surveys in the summ...To better understand the ecological and economic benefits of short-term grazing exclusion on the aboveground net primary productivity(ANPP)of alpine pastures,we conducted annual multi-site transect surveys in the summers from 2009 to 2011 and calculated the aboveground biomass discrepancy(ABD)between grazed and ungrazed pastures at plant community and economic group levels for three zonal alpine grassland types—meadow,steppe,and desert-steppe—across the northern Tibetan Plateau.Our results indicated that aboveground biomass(AGB)significantly differed among grassland types and declined northwesterly from 64.07 to11.44 g m-2with decreasing precipitation and increasing temperature.The mean ABD exhibited considerable community dependency,with meadow(12.47 g m-2)[steppe(6.91 g m-2)[desert steppe(2.54 g m-2),and it declined from 25.42 to 1.29 g m-2with decreasing precipitation and increasing temperature.‘Good forage’,i.e.grasses and sedges,benefited most from grazing exclusion,followed by edible forbs.With longer grazing exclusion durations(GEDs),the aboveground biomass of poisonous locoweeds initially decreased and then increased compared with the adjacent grazed sites.In the nested analysis of co-variances with a general linear model,growing season precipitation(GSP;from May to September)accounted for 52.67%ofthe observed variation in AGB,followed by AGT(9.77%)and pasture management systems(PMSs;grazing or grazing-excluded,5.31%).The variation in ABD was explained primarily by AGT(16.52%),GED(20.25%),and the interaction of AGT 9 GED(19.58%).Our results confirm that precipitation is the primary factor controlling the ANPP of alpine grasslands on the Northern Tibetan Plateau and that the ecological benefits arising from grazing exclusion are also partly dependent on grassland type and exclusion duration.Therefore,spatial and temporal variations in growing season precipitation and plant functional traits or economic group composition should be jointly considered when developing policies concerning the management and spatial layouts of grazing exclosures in this region.展开更多
Tillage is one of the agricultural management practices that significantly impacts agroecosystems,crop production,and the environment.Conventional tillage(CT)practices alter the soil environment and induce organic con...Tillage is one of the agricultural management practices that significantly impacts agroecosystems,crop production,and the environment.Conventional tillage(CT)practices alter the soil environment and induce organic constituents’decomposition and the emission of greenhouse gases(GHGs),which contribute to the greenhouse effect and global warming.Low organic matter,biological diversity,aggregate stability,high erosion and degradation of the soil environment,and sequestration strength are additional factors associated with CT,which negatively affect food security and environmental sustainability.As a result,CT is no more beneficial in the long run;consequently,zero tillage(ZT)could be a viable candidate for sustainable agriculture.The review to establish this systematically compared and summarized the effect of tillage systems(i.e.CT and ZT)by synthesizing and interpreting published data(>150 peer-reviewed articles)with>200 observations on soil ecosystem services and properties/agroecosystem,crop yield/food security,GHG emission,and carbon sequestration/environmental resilience.The review established that ZT improves soil structure,aggregate stability,biological diversity,organic matter and nutrients,water and water use efficiency,and reduces soil degradation,erosion,tillage machinery impacts,and GHG emissions.It allows timely seeding and better crop growth,increases yield and food security,improves carbon sequestration,strengthens soil storage potential,and helps to mitigate the adverse effects of climate change on environmental resilience.Based on various latent direct and indirect benefits,resource-saving ability,and broad adoption scope of ZT,it is corroborated that ZT is a practical and potential approach for improved and sustainable agroecosystem,food security,and environmental resilience.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0304-02)Joint Chinese Academy of Sciences(CAS)-Max Planck Society(MPG)Research Project(HZXM20225001MI)+3 种基金the Strategic Priority Research Program A of Chinese Academy of Sciences(XDA20050104)the National Natural Science Foundation of China(42041005)CAS Light of West China Programthe Fundamental Research Funds for the Central Universities。
基金supported by the National Natural Science Foundation of China(41171044)Knowledge Innovation Project of the Chinese Academy of Sciences(XDB03030401&KZCXZ-XB3-08)by a General Financial Grant from theChina Postdoctoral Science Foundation(2013M530716)
文摘To better understand the ecological and economic benefits of short-term grazing exclusion on the aboveground net primary productivity(ANPP)of alpine pastures,we conducted annual multi-site transect surveys in the summers from 2009 to 2011 and calculated the aboveground biomass discrepancy(ABD)between grazed and ungrazed pastures at plant community and economic group levels for three zonal alpine grassland types—meadow,steppe,and desert-steppe—across the northern Tibetan Plateau.Our results indicated that aboveground biomass(AGB)significantly differed among grassland types and declined northwesterly from 64.07 to11.44 g m-2with decreasing precipitation and increasing temperature.The mean ABD exhibited considerable community dependency,with meadow(12.47 g m-2)[steppe(6.91 g m-2)[desert steppe(2.54 g m-2),and it declined from 25.42 to 1.29 g m-2with decreasing precipitation and increasing temperature.‘Good forage’,i.e.grasses and sedges,benefited most from grazing exclusion,followed by edible forbs.With longer grazing exclusion durations(GEDs),the aboveground biomass of poisonous locoweeds initially decreased and then increased compared with the adjacent grazed sites.In the nested analysis of co-variances with a general linear model,growing season precipitation(GSP;from May to September)accounted for 52.67%ofthe observed variation in AGB,followed by AGT(9.77%)and pasture management systems(PMSs;grazing or grazing-excluded,5.31%).The variation in ABD was explained primarily by AGT(16.52%),GED(20.25%),and the interaction of AGT 9 GED(19.58%).Our results confirm that precipitation is the primary factor controlling the ANPP of alpine grasslands on the Northern Tibetan Plateau and that the ecological benefits arising from grazing exclusion are also partly dependent on grassland type and exclusion duration.Therefore,spatial and temporal variations in growing season precipitation and plant functional traits or economic group composition should be jointly considered when developing policies concerning the management and spatial layouts of grazing exclosures in this region.
基金The present study was conducted with the support of the China Postdoctoral Council,IEDA,CAAS,National Natural Science Foundation of China(Grant No.42007073)technologies for GHG mitigation and carbon sequestration,supported by MARA,PRC(Grant No.13210352)+1 种基金Ministry of Science and Technology National Science and Technology Support Program(2015BAC02B06)the Sino-German Cooperation Program on Agriculture and Climate Change(CHN 19-02).
文摘Tillage is one of the agricultural management practices that significantly impacts agroecosystems,crop production,and the environment.Conventional tillage(CT)practices alter the soil environment and induce organic constituents’decomposition and the emission of greenhouse gases(GHGs),which contribute to the greenhouse effect and global warming.Low organic matter,biological diversity,aggregate stability,high erosion and degradation of the soil environment,and sequestration strength are additional factors associated with CT,which negatively affect food security and environmental sustainability.As a result,CT is no more beneficial in the long run;consequently,zero tillage(ZT)could be a viable candidate for sustainable agriculture.The review to establish this systematically compared and summarized the effect of tillage systems(i.e.CT and ZT)by synthesizing and interpreting published data(>150 peer-reviewed articles)with>200 observations on soil ecosystem services and properties/agroecosystem,crop yield/food security,GHG emission,and carbon sequestration/environmental resilience.The review established that ZT improves soil structure,aggregate stability,biological diversity,organic matter and nutrients,water and water use efficiency,and reduces soil degradation,erosion,tillage machinery impacts,and GHG emissions.It allows timely seeding and better crop growth,increases yield and food security,improves carbon sequestration,strengthens soil storage potential,and helps to mitigate the adverse effects of climate change on environmental resilience.Based on various latent direct and indirect benefits,resource-saving ability,and broad adoption scope of ZT,it is corroborated that ZT is a practical and potential approach for improved and sustainable agroecosystem,food security,and environmental resilience.
