A Comparison Study On Avian Community Diversity Between The Coal Mining Subsidence Wetlands And The Natural Wetlands

The coal mining subsidence wetland has a certain impact on the bird community,as a new type of wetland gradually formed after coal mining.The community structure and seasonal dynamics of coal mining subsidence wetland and natural wetland were surveyed in order to understand the impacts of environmental factors especially human disturbance on bird diversity of wetland community.The bird survey was conducted from December 2014 to November 2015 in six wetlands,that is Jiaogang Lake National Wetland Park(Jiaogang Lake wetland),Sanchahe National Wetland Park(Sanchahe wetland),Liangwan Provincial Wetland Park(Liangwan wetland),Linhuan coal mining subsidence(Linhuan wetland),Digou National Wetland Park(Digou wetland),Nanhu National Wetland Park(Nanhu wetland).A total of 51 quadrats and transects were used.We surveyed the birds in these 6 wetlands each quarter,and analyzed the bird community composition in different habitats and seasons,studied the bird diversity differences in natural and artificial wetlands,especially the impacts of coal mining subsidence on bird diversity.The main results are as follows.A total of 108 species of birds were recorded in coal mining subsidence wetland,belonging to 15 orders and 36 families.Among them,the number of species and families of Passeriformes all accounted for the main proportion.Waterbirds in Digou wetland had the largest number of species,with a total of 30 species(35.3%).The density of birds in Nanhu wetland was highest,which was 38.85±6.79 ind/hm2.The bird density of Digou wetland and Linhuan wetland were similar,which were 27.6±5.47ind/hm2 and 27.38±3.11ind/hm2 respectively.The bird density had significant differences in three subsidence wetland(F(2,15)=7.55,P<0.01),and the difference in bird density between the Nanhu wetland(N)and Linhuan wetland(L)and Digou wetland(D)reached a significant level(NL:t=1.74,P<0.05;ND:t=2.04,P<0.05).The bird diversity index of Nanhu wetland was the highest and that of Linhuan wetland was the lowest.The bird species,diversity index and the subsidence time were not significantly correlated with the time and area of subsidence in Linhuan wetland,Nanhu wetland and Digou wetland.A total of 117 species were recorded in natural wetlands,belonging to 16 orders and 38 families.Among them,the number of species and families of Passeriformes all accounted for the main proportion.The number of waterbirds was largest in Jiaogang Lake wetland,with a total of 31 species(32.3%).The density of birds in Sanchahe wetland was highest,which was 36.94±3.78 ind/hm2.Followed by the Jiaogang Lake wetland,the density of birds was 35.94±6.16 ind/hm2.And that was the lowest in Liangwan wetland,which was 34.48±4.27 ind/hm2.Variance analysis of bird density in different natural wetlands showed significant difference(F(2,5)?10.27,P<0.05).The bird diversity index of Sanchahe wetland was the highest,and that of Liangwan wetland was the lowest.The comparison between two types of wetland bird communities showed that t Charadriiformes and Ciconiiformes of natural wetland birds were more than those of the sinking wetland,while the number of Passeriformes was slightly less than that of the subsidence wetland.There were 37 species waterbirds in natural wetland,accounting for 31.1%of total bird species.While there are fewer waterbirds in the subsidence wetland,33 species,accounting for 30.6%.The density of birds in natural wetland was 35.45±4.96ind/hm2,while that of the subsidence wetland was lower than that of natural wetland,and the density was 31.28±7.56 ind/hm2.Liangwan wetland and Nanhu wetland had the lowest similarity index(0.777),Jiaogang Lake wetland and Sanchahe wetland had the highest similarity index(0.895).We divided Digou wetland,Nanhu wetland and Linhuan wetland into one group,Jiaogang Lake wetland,Sanchahe wetland,and Liangwan wetland into one group in cluster analysis.There was higher bird diversity in natural wetlands with uniform distribution,lower bird diversity in constructed wetlands with uneven distribution.Landscape heterogeneity and human disturbance are important factors that had effects on wetland bird distribution.Independent sample t tests were conducted for the natural wetland and the subsidence wetland in the species number,the density,the Shannon index,the uniformity index and the advantage index.The results showed that it was significantly different in the species number between the natural wetland and the subsidence wetland(t=-2.393,df=205,p=0.018<0.05).But it was indistinctively different in the density,the Shannon index,the uniformity index and the advantage index.