Effects of Grazing on Population Dynamics and Diversity of Grasshoppers in Desert Steppe
A long-term grazing experiment established in 2004 within a Stipa breviflora desert steppe investigated the population dynamics and abundance of grasshoppers under various grazing intensities by sheep(Ovis aries)during the grazing period.Four grazing intensities were implemented:no grazing(CK),light grazing(LG),moderate graz-ing(MG),and heavy grazing(HG),corresponding to stocking rates of 0,0.91,1.82 and 2.71 sheep units/hm2,respectively.The results showed that the CK plot harbored three dominant grasshopper species:Myrmeleotettix pal-palis,Calliptamus abbreviatus,and Dasyhippus barbipes.Grazing intensity significantly influenced grasshopper com-munity composition,with Calliptamus abbreviatus dominance replaced by Oedaleus asiaticus under grazing pressure.During peak abundance periods,MG and HG treatments exhibited increased abundances of Myrmeleotettix palpalis,Dasyhippus barbipes,and Oedaleus asiaticus compared to the CK(P<0.05).However,Calliptamus abbreviatus abundance declined significantly due to grazing(P<0.05).Furthermore,grasshopper species diversity showed a negative correlation with grazing intensity and a positive correlation with plant diversity(P<0.05).These findings suggest that the response of the abundance of dominant grasshopper species to different grazing intensities was not con-sistent,and heavy grazing reduces grasshopper species diversity,and alters dominant grasshopper species.
Desert steppeGrazingGrasshopperTemporal dynamicsGrasshopper species diversity
NETL
NSTL
万方数据
