Contrasting effects of N fertilization and mowing on ecosystem multifunctionality in a meadow steppe  

作　　者：Haiying Cui Wei Sun Manuel Delgado-Baquerizo Wenzheng Song Jian-Ying Ma Keying Wang Xiaoli Ling 

机构地区：[1]Key Laboratory of Vegetation Ecology of Ministry of Education,Institute of Grassland Science,School of Life Science,Northeast Normal University,Changchun 130024,China [2]Departamento de Sistemas Fisicos,Químicos y Naturales,Universidad Pablo de Olavide,Carretera de Utrera Km.1,41013 Sevilla,Spain [3]Key Laboratory of Biogeography and Bioresource in Arid Land,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China

出　　处：《Soil Ecology Letters》2020年第4期268-280,共13页土壤生态学快报（英文）

基　　金：supported by the National Key Research and Development Program of China(2016YFC0500602);the National Natural Science Foundation of China(31570470,31870456);the Fundamental Research Funds for the Central Universities(2412018ZD010);the Program of Introducing Talents of Discipline to Universities(B16011);supported by the Spanish Government under Ramon y Cajal(RYC2018-025483-I);support from a Large Research Grant from the British Ecological Society(Grant Agreement No.LRA17\1193,MUSGONET);support from Chinese Scholarship Council(CSC).

摘　　要：There is little experimental field evidence on how multiple essential land use intensification drivers(LUIDs),such as nitrogen(N)fertilization and mowing,interact to control ecosystem multifunctionality.Here,we conducted a 4-year field experiment in a meadow steppe in northeast China and evaluated the direct and indirect effects of mowing and N fertilization on a range of ecosystemfunctions associated with nutrient cycle,carbon stocks,and organic matter decomposition during the past 2 years of the experiment(2017 and 2018).Mowing had negative effects on the ecosystem multifunctionality index(EMF),carbon(C)cycle multifunctionality index(CCMF),and N cycle multifunctionality index(NCMF)in 2 years of sampling.However,in general,the responses of multifunctionality to N fertilization were ratespecific and year-dependent.N fertilization had positive effects on EMF,CCMF,NCMF,and phosphorus(P)cycle multifunctionality index(PCMF)in 2017,with the higher precipitation rate during the growing season,which was likely associated with the strong monsoon season.However,in 2018,EMF,CCMF,and NCMF increased at the lower N fertilization levels(£10 g N m^(-2) yr^(-1)),but decreased at higher N rates.N fertilization had consistent positive effects on PCMF in the 2 years of sampling.The effects of land use drivers on multifunctionality were indirectly influenced by bacterial biomass,plant richness,and soil moisture changes.Our results also indicated that the impacts of land use drivers on multifunctionality played an important role in maintaining a range of functions at low levels of functioning(<50% functional threshold).Low N fertilization levels(£10 g N m^(-2) yr^(-1))were able to reduce the negative effects of mowing on ecosystem multifunctionality while promoting plant biomass(food for livestock)and C storage.These findings are useful for designing practical strategies toward promoting multifunctionality by managing multiple LUIDs in a meadow steppe.

关 键 词：Ecosystem multifunctionality Sustainable grassland management Land use intensification MOWING Multi-threshold approach Nitrogen fertilization 

分 类 号：X171[环境科学与工程—环境科学]