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Effects of fire and grazing on above‐ground biomass and species diversity in recovering grasslands in northeast China
Author(s) -
Huang Yue,
Wang Kelin,
Deng Bowen,
Sun Xuekai,
Zeng DeHui
Publication year - 2018
Publication title -
journal of vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 115
eISSN - 1654-1103
pISSN - 1100-9233
DOI - 10.1111/jvs.12641
Subject(s) - grazing , biomass (ecology) , forb , agronomy , environmental science , grassland , conservation grazing , pasture , ecology , species diversity , biology , agroforestry
Abstract Questions Fire and grazing can affect plant communities through different pathways in grasslands. However, little is known about how these disturbances affect plant communities in recovered semi‐arid grasslands. Here we investigated effects of prescribed fire, sheep grazing and their interactions on above‐ground biomass and species diversity in degraded semi‐arid grasslands recovered from cropping agriculture. Location Keerqin grasslands, northeast China. Methods A short‐term grazing and burning experiment with split‐plot design was conducted, with burning applied at the main plot level and grazing applied at the subplot level. After 1 year of spring burning and 2 years of grazing by sheep, the above‐ground biomass, species diversity, biomass proportion of plant functional groups and soil resource availability of the grasslands were measured and compared between treatments using a split‐plot ANOVA model. Results One‐year of spring fire significantly increased above‐ground biomass, while 2 years of grazing by sheep significantly decreased it. Species diversity was reduced by grazing in the burned plots but enhanced by grazing in the unburned plots. Fire significantly increased the biomass percentage of grasses and reduced that of forbs. Fire also changed soil water content and inorganic N concentration, and grazing enhanced light intensity to the soil surface. Moreover, above‐ground biomass was positively related to soil water content and inorganic N concentration under both disturbances. Species diversity had a positive linear relationship with biomass percentage of grasses and a negative relationship with biomass percentage of forbs under sheep grazing. Conclusions Both short‐term fire and grazing are important in determining the above‐ground biomass in degraded semi‐arid grasslands, and their effects are opposite. Grazing coupled with fire has negative effects on species diversity. Thus, we advise that fire and grazing should be carefully applied when used in the same management regime to maintain above‐ground biomass and species diversity in managing this grassland ecosystem.