Grazing Effects On Reproductisve Ecology Of Emberiza Jankobwskii

Grazing is the main way for human to use natural grassland,and is also an important factor to impact on natural grassland and the wild animals.Here we investigated the reproductive status,nest site selection and reproductive success of Emberiza jankowaski in the fenced and non-fenced areas from May to July in 2015 and 2016 at Gahatu town,Zhalute Banner,Tongliao City,Inner Mongolia,China.Statistical analysis of the population density of Emberiza jankowaskii and the area of plaque.Showed that there was no significant difference(r=-.105,P=.745).We also found that there were extremely significant differences in the density of Armeniaca Siberian,height of Stipa baicalensis,hay density,grass density and the proportion of open space between fenced and non-fenced areas(t =-3.090,p <0.01).Significant differences were also detected in the height of Armeniaca Siberian and density of Stipa baicalensis(t =2.286,p <0.05),while the average height of the grass,the plant species and the thickness of the eroded grass were not significantly different.On the selection of habitat of Emberiza jankowaskii,the principal component analysis was carried out.The results showed that the five plants(Lespedeza bicolor,Stipa baicalensis,Aneurolepidium chinense,Filifolium sibiricum,Cleistogenes spurrosa)were dominant plants in the sample area.Statistical analysis of vegetation characteristics in the breeding grounds of the Emberiza jankowaskii's at different grazing intensities.Showed that there was a significant correlation between the grazing intensity and the ratio of bare land(r = 0.977,P = 0.023)and grass height(r =-0.992,p=0.008)under different grazing intensities.With the increasing grazing intensity,the proportion of bare grass is increasing,and the height of grass is decreasing.During the process,89 nests and 202 eggs were found,30 nests of them were in the fence area(33.70%).The number of nests with all the fledgings leave nest successfully was 4(4.49%),and the total number of eggs was 119(58.91%);hatching number was 34(16.83%);successful fledgings were 15(7.43%).The number of nests in non-fence area was 25(28.09%),1 of them(1.12%)was flying success;the total number of eggs was 83(41.09%),24 of them(11.88%)hatched successfully,and then 4 of them(1.98%)were fledging success.Moreover the average area of patch was 67.62+/-59.55 hm2,and the average quantity of Emberiza jankowaskii in the patches was 17.08+/-19.99.The relationship between patch area and population quantity was significant negative,there was a significant negative,suggesting the more the number of grazing herds,the smaller the population density of the Emberiza jankowaskii's population.On the selection of habitat of Emberiza jankowaskii,the principal component analysis was carried out.