Feature Of Plant Community In The Habitat Of Giant Pandas In Taibai Mountain And The Influence Of Fargesia Qinlingensis Flowering On Giant Panda

A large area of Fargesia qinlingensis flowering happened in Taibaishan Nature Reserve.Bamboo flowering event result in the loss of habitat and even reduce the food availability of giant pandas(Ailuropoda melanoleuca).The transect line and sampling method were used to investigate the vegetation characteristics of giant panda habitat under the bamboo flowering,including the characteristics of plant community,bamboo stand of F.qinlingensis,and the spatial associations of main tree species with understory flowering F.qinlingensis.Meanwhile,infrared camera trap technology was used to monitor the activities of giant panda under bamboo forestry.The results showed that:(1)There exist 36 plant species,belong to 31 genera,18 families in the habitat of giant pandas in Taibaishan Nature Reserve.All tree plants belong to 6 species,5 genera of 3families with dominant species Betula albo-sinensis and Abies fargesii.Shrub layer shares 14 species,12 genera of 7 families,with the higher number of F.qinlingensis.Herb layer shares16 species,14 genera of 10 families.The absolute advantage of F.qinlingensis in the shrub layer led to the richness index,diversity index and evenness index of tree layer and herb layer in the community were lower than that of shrub layer.The population structure of B.albo-sinensis and Betula platyphylla were growing,while a deciling in the population of A.fargesii was observed in the plot.There were many individuals in the middle age group and fewer tree seedings of the six main tree populations.(2)In the habitat of giant pandas,the average height and basal diameter of F.qinlingensis was 2.46�0.66 m and 7.41�1.91 mm,respectively.There was no significant difference between flowering bamboo(FB)and non-flowering bamboo(NFB).Bamboo density and coverage was 54/m2 and 30.30 %.In age group of bamboo,the annual bamboo was 7.64 %,biennial bamboo was 5.56 %,the perennial bamboo and flowering bamboo was 54.32 % and32.57 %,respectively.Except the crude fiber,the contents of nutrient in various parts of FB and NFB mostly displayed leaf>stem>stem.Crude protein had same trend in FB and NFB:leaves>branches>stems,but it was significantly lower in FB than in NFB,while the content of crude fiber showed the opposite trend.They both was no significant difference in crude fat.Soluble sugar was significantly lower in leaves and greater in the stems of FB than NFB.(3)The three main tree species,A.fargesii,B.platyphylla and B.albo-sinensis in Abies fargesii forest in Taibai Mountain,showed significantly aggregated distributions at small scales and random distributions at large scales,and the degree of aggregation decreased with increasing spatial scales.Spatial associations among tree species were mainly found at small scales and gradually disappeared with increasing scales.A.fargesii and B.platyphylla were positively associated with flowering F.qinlingensis at large and medium scales,whereas B.albo-sinensis were negatively associated with flowering bamboos at large and medium scales.(4)Some bamboo stumps and discarded tops by giant panda as well as some feces with inflorescences were found in FB forest during three years in field survey in Taibaishan Nature Reserve.Moreover,with the flowering bamboo area constantly increased(26.7 % of the bamboo forest area in 2013,33.9 % in 2014 and 52.3 % in 2015)during three years,the number of inflorescence in feces gradually increased(17.67,49.82,65.67),while the times of giant panda's activity observed was decreased in flowering bamboo forest(20,18,11).The elevation floor of feeding sites of giant panda was extremely higher in 2015(P=0.000)than that of other years,and its activity range changed from 2350-2450 m to 2460-2630 m.The dominant species of shrub layer was F.qinlingensis with medium density,low coverage and declining population in the habitat of giant pandas in Taibaishan Nature Reserve.The spatial distribution patterns of flowering F.qinlingensis were influenced by the spatial distribution patterns of upper trees.In face of large area bamboo flowering,the foraging strategy and spatial behavior of giant panda would changed.