Bird diversity and waterbird habitat preferences in relation to wetland restoration at Dianchi Lake, south-west China

Background:Restoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats.Much research has been carried out on the impacts on birds of wetland restoration and management projects in China. Studies have mainly investigated central or coastal wetlands,while inland wetlands in remote areas have been much less studied. We focused on examining the response of wild birds to wetland restoration in Dianchi Lake,south-west China. Methods: The line transect method was performed at 26 sampling plots.Three of these were in the city,and to acquire all wild bird data 23 plots were located every 2-8 km along the shore of Dianchi Lake, between December 2011 and November 2013.We collected all related bird records by searching the available literature, articles, newspapers and records of birdwatchers to compare species variation before and after implementation of wetland restoration.To measure the relationships between waterbird assemblages and habitat structures, we used canonical correspondence analysis (CCA) to pair the main matrix of bird assemblages with a second matrix of habitat variables. Results: We recorded 182 bird species belonging to 51 families and 17 orders. Of the species, 42 were new records for Kunming City and 20 were new records for Yunnan Province. Ten waterbird species were found to have disappeared from the shore of Dianchi Lake.CCA results indicated that waterbirds could be divided into four categories based on their habitat preference:synanthropic (wintering gulls), special habitat (shorebirds),semi-natural (wintering coots and ducks) and disturbance-tolerant (resident) species.Conclusions:Our study is the first to consider the entire wild bird community throughout the year and discuss the species variation before and after wetland restoration projects launched for Dianchi Lake.Distinct habitat requirements of different waterbird groups were detected in our study,suggesting different types of restoration and management should be implemented.

Decay-like fracture diagnosis of composite insulator based on small sample virtual expansion and radar graph mapping

Due to the complexity of test procedures and the high cost of measurements,the mechanism of the decay-like fracture is unclear,which brings hard concepts and the small sample problem.Therefore,it is intractable to establish accurate data-driven models.To solve the above mentioned problems,this paper proposes a data-driven modeling method based on radar graph mapping models and virtual sample generation(Radar-VSG).The main idea of the proposed method is to construct and select the most appropriate input features by using radar graph mapping,and to generate virtual samples by using the local outlier factor based on the isometric feature mapping algorithm(Isomap-LOF).To verify the effectiveness of our approach,a set of 27 training samples and 127 testing samples from China Southern Power Grid was applied.Experimental results suggested the accuracy was up to 100%after adding more than 27 virtual samples,with a 4.75%improvement.And the model has the best generalisation ability for 270 virtual samples,with the root mean square error of 0.018.Compared with support vector machine and four advanced VSG methods,the proposed Radar-VSG can achieve better performance.