西安地区鸟类区系30年的变化

Avifauna Changes in 30 Years (1977 to 2007) in Xi′an,China

采取路线调查法,在1977～1980年和2004～2007年两个阶段对西安地区的鸟类进行了调查,并通过比较来说明西安地区鸟类30年来的变化。将调查地区分为4种生境类型(浅山地带、农田村落、水域和城市建筑区),并在每种生境类型中进行鸟类物种和种群数量统计。结果表明:2004～2007年调查的物种数(149种)比1977～1980年调查的物种数(138种)略有增高,在人为干扰相对较少的浅山地区鸟类物种在两次调查中均最多,而人口集中的城市建筑区物种在两次调查中均最少。比较两个阶段的鸟类,有24种在2004～2007年的调查中没有见到,但又新增了鸟类34种,每种生境类型中的物种组成和每个物种的数量在不同阶段也不同。在城市建筑区植食性鸟类增多,而在浅山地区食虫鸟类相对更多。随着城市化进程的加快,需要关注城市鸟类的保护。

Avifauna changes in 30 years in Xi＇ an were analyzed based on two bird surveys by line transect method conducted from 1977 to 1980 and 2004 to 2007.Totally, 138 species were recorded in the first bird survey and 149 species in the second survey in four types of habitat, namely shallow hill zone, village/cropland, open water, and city building zone. Highest bird richness was found in the shallow hill zone where the ecological environment was undisturbed, while in city building zone the bird richness was the lowest in both of the bird surveys. Comparing with the result got in the first survey, 24 species were not found and 34 birds have been added in the list, while 24 birds recorded in the first survey have not been found in the second survey. The species richness and abundance in each habitat was different for the two surveys. More bird species feeding on foliage have been recorded in the city building zone and more insectivorous birds have been recorded in the shallow hill zone in the second survey comparing with the result of the first bird survey. More attention should be paid to the urban bird conservation as the size of city expanded speedily.