Alteration Of Birds Diversity In Two Periods In The Lakeshore Of Dianchi Lake And Its Correlation With Land Cover Type

Dianchi Lake,the largest plateau lake in Southwest China,is an important h abitat and stopover for many wetland birds.The urban development of Kunming has greatly changed the land cover types in the lakeside area of Dianchi Lake,b ut it is not clear what impact these changes have on birds and their habitats.In this study,based on the data of birds and their habitats from 34 samples in the lakeside area of Dianchi Lake from 2012 to 2013,the same method was used to conduct bird surveys again from 2018 to 2019.The combination of eCognition Developer 8.7 and ArcGIS 10 visual interpretation taxonomy analyzes land cover over the same period.Screen the linear regression model through the weight coe fficient of the minimum AICc model,select the model with ?AICc <2.0 and the number of independent variables ? 2 as the candidate model,and analyze the c orrelation between bird diversity and land cover type changes during the two tim e periods.The main results obtained are as follows.(1)So far,Dianchi Lake and its lakeside area have recorded 248 species of 17 orders,55 families and birds.Among them,in this survey,a total of 157 species of 16 orders,49 families,and birds were recorded in 34 samples;of 23 samples compared,a total of 80,431 species of 156 species,44 families,and 14 orders of birds were recorded from 2012 to 2013.From 2018 to 2019,there we re 51 orders of 136 species and 136 species in 14 orders and 46 families.(2)In the two periods of comparison,the number of swimming birds incr eased from 11 species 3436(4.27%)to 15 species 4079(7.94%);the number of wading birds decreased from 46 species 52716(65.54%)to 30 species 39152(76.26%);the number of songbirds decreased from 81 species 23376(29.06%)to 73 species 7619(14.84%);the number of other ecotypes of birds decreased to v arying degrees.In terms of residence type,the number of species of tourist birds decreased from 40 to 17;the number of species of summer migratory birds rem ained 12;the number of species of resident birds decreased from 75 to 72;the number of species of winter migratory birds decreased from 52 to 50;the numb er of species of rare or unknown species increased from 9 to 10.(3)Combining the changes in land cover of the 23 sample sites in two p eriods,among them,the proportion of the area showing an increasing trend is fo rest land(60.82%),roads(15.10%),built-up land(84.94%),and pits and rivers(15.96 %),Lake water surface(23.06%),herb wetland(7.83%);The proportion o f area showing a decreasing trend includes grassland(-6.32%),dry land(-47.52%),greenhouse(-83.96%),bare land(-58.60%),paddy field(-11.32%).(4)The change in the number of bird species in the lakeside area of Dia nchi Lake is negatively correlated with the change in the proportion of built-up area and grassland area,that is,the increase in the proportion of built-up area a nd grassland area within the sample point will make the bird species richness re duce.The change in the species richness of waterbirds is negatively correlated w ith the change in the proportion of dry land area,and positively correlated with the change in the proportion of paddy field area.The change in species richness of shorebirds is negatively correlated with the change in the proportion of built-u p land and dry land area,and positively correlated with the change in the propo rtion of bare land area and the area of rivers and ditches on the surface of pon ds and ponds.Among them,the change in the proportion of built-up land is the most important factor affecting the change in the species of shorebirds.(5)In this study,by investigating the changes in bird species,number,eco logical types,residence types,and land cover types at the same point in the lak eside area of Dianchi Lake,the relationship between the two can be analyzed fo r future planning and layout And ecological restoration provides more basis.The resulting Dianchi Bird List also provides monitoring data for future studies of Di anchi Birds.