title: Effects of stocking rate on the variability of peak standing crop in a desert steppe of Eurasia grassland.
abstract: Proper grazing management practices can generate corresponding compensatory effects on plant community production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how grazing influences plant community attributes and the variability of standing crop. We examined the effects of sheep grazing at four stocking rate treatments [control, 0 sheep ha(-1) month(-1); light (LG), 0.15 sheep ha(-1 )month(-1); moderate (MG), 0.30 sheep ha(-1) month(-1); and heavy (HG), 0.45 sheep ha(-1) month(-1)] on standing crop at the community level and partitioned by species and functional groups, in the desert steppe of Inner Mongolia, China. The treatments were arranged in a completely randomized block design over a 9-year period. Standing crop was measured every August from 2004 to 2012. Peak standing crop decreased (P < 0.05) with increasing stocking rate; peak standing crop in the HG treatment decreased 40 % compared to the control. May-July precipitation explained at least 76 % of the variation in peak standing crop. MG and HG treatments resulted in a decrease (P < 0.05) in shrubs, semi-shrubs, and perennials forbs, and an increase (P < 0.05) in perennial bunchgrasses compared to the control. The coefficients of variation at plant functional group and species level in the LG and MG treatments were lower (P < 0.05) than in the control and HG treatments. Peak standing crop variability of the control and HG community were greatest, which suggested that LG and MG have greater ecosystem stability.
authors.affiliation: Department of Grassland Science, College of Ecology and Environmental Science, Inner Mongolia Agricultural University, Hohhot, 010018, Inner Mongolia, People's Republic of China, zhoungwuwang1979@163.com.
authors.forename: Zhongwu
authors.initials: Z
authors.lastname: Wang
authors.forename: Shuying
authors.initials: S
authors.lastname: Jiao
authors.forename: Guodong
authors.initials: G
authors.lastname: Han
authors.forename: Mengli
authors.initials: M
authors.lastname: Zhao
authors.forename: Haijun
authors.initials: H
authors.lastname: Ding
authors.forename: Xinjie
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Wang
authors.forename: Eldon L
authors.initials: EL
authors.lastname: Ayers
authors.forename: Walter D
authors.initials: WD
authors.lastname: Willms
authors.forename: Kris
authors.initials: K
authors.lastname: Havsatad
authors.forename: Lata
authors.initials: L
authors.lastname: A
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D017753:Ecosystem; D060434:Herbivory; D008986:Mongolia; D006109:Poaceae / Q000254:growth & development*; D011891:Rain; D012756:Sheep / Q000502:physiology*