title: Long term prevention of disturbance induces the collapse of a dominant species without altering ecosystem function.
abstract: Limitation of disturbances, such as grazing and fire, is a key tool for nature reserve management and ecological restoration. While the role of these disturbances in shaping ecosystem structure and functioning has been intensively studied, less is known about the consequences of long-term prevention of grazing and fire. Based on a 31-year study, we show that relative biomass of the dominant grass, Leymus chinensis, of grasslands in northern China declined dramatically, but only after 21 years of exclusion of fire and grazing. However, aboveground net primary productivity (ANPP) did not decline accordingly due to compensatory responses of several subdominant grass species. The decline in dominance of L. chinensis was not related to gradually changing climate during the same period, whereas experimentally imposed litter removal (simulating fire), mowing (simulating grazing), fire and moderate grazing enhanced dominance of L. chinensis significantly. Thus, our findings show that disturbances can be critical to maintain the dominance of key grass species in semiarid grassland, but that the collapse of a dominant species does not necessarily result in significant change in ANPP if there are species in the community capable of compensating for loss of a dominant.
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.|Department of Biology, Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523 USA.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
authors.forename: Honghui
authors.initials: H
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
authors.forename: Zhengwen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Global Change and Alpine Ecosystem Research Laboratory, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.|Institute of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland.
authors.forename: Dan F B
authors.initials: DF
authors.lastname: Flynn
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yang
authors.affiliation: Shenzhen Baoan Qianlong School, Shenzhen 518131, China.
authors.forename: Fumei
authors.initials: F
authors.lastname: Lü
authors.affiliation: Department of Biology, Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado 80523 USA.
authors.forename: Melinda
authors.initials: M
authors.lastname: Smith
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.|State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Han
mesh_terms: D058448:Biota; D002681:China; D005390:Fires / Q000517:prevention & control*; D065948:Grassland; D060434:Herbivory; D006109:Poaceae; D011157:Population Dynamics