Effects Of Vegetation Succession On The Bird Communities In Xinglongshan National Nature Reserve

The community structure and seasonal dynamic of bird communities of four successional stages (shubland , deciduous forest, mixed forest and coniferous forest) in Xinglongshan National Nature Reserve, Gansu were investigated, and four time phases were chosen to represent four seasons - April and May , 2004 as spring, June to August, 2004 as summer, September and Octomber, 2003 as autumn , and November, 2004 to January, 2005 as winter. A total of 55 species of birds were recorded in the four habitates, and they belong to 6 catagories of guilds.Among the four habitates, the number of bird species in the shrub was the largest, with the other three almost in the same level. This results showed that shrub plays an important role in the maintenance of bird diversity. In the four successional stages, 16 species of birds such as Tarsiger cyanurus, Phoenicurus frontal is, Phoenicurus erythrogaster and Paradoxornis conspicillatus are only existed in the shrub. 3 species(Buteo buteo, Dendrocopos canicapillus and Phoenicurus schisticeps) were only in the deciduous forest,. Lophobasileus elegans only existed in the coniferous forest. And all the birds in the mixed forest distributed in at least one of the other three stages. From the results above, we conclude that the shrub can provide more suitable habitat environment for birds, but as the metaphase of the succession, mixed forest has more similarity to deciduous forest and coniferous forest,which was why no birds only existed in it. Analysis of Variance Procedure suggested that the bird density of the four stages in every season differenced obviously. Shrub is the first stage of the succession , its bird divisity was the highest and the amount of the bird species was the largest. However, as the second stage of the succession, deciduous forest is mainly consisted of broadleaf trees, so it has fewer species of plants, which results in its low bird diversity and fewer bird species.Mixed forest and coniferous forest almost had the same bird divisities and the amount of bird species in four seasons.Comparing the bird community in a habitat of four seasons, We found the bird dinversity index in deciduous forest, mixed forest and coniferous forest followed a similar rule, which were summer was the higest, spring took the second place, autumn took the third place and winter was the lowest.At the same time, the trend about the richness of bird species was the same with the bird diversity index, which was mainly caused by migration. But, the shrub was exceptional to the rules above, its diversity index and richness of species decreased from spring to winter in turn, in which we can find that the shrub has its particularity.Because many birds only exist in a special habitat and some birds choose its preferable habitat ,so we should adopt manpower interference to work on the procession of succession to maintain or even increase the bird diversity on the sight level.