城市化对杭州市鸟类营巢集团的影响

为了了解城市化对鸟类营巢集团的影响，2007年3月至2007年8月，沿城市化梯度在杭州地区的城区、城乡结合区、农田区、农林交错区和自然林区等类型栖息地内设置3 000 m长、100 m宽的样线各18条，共计90条；并对其鸟类物种与群落营巢集团进行调查。调查共记录到繁殖鸟类96种，根据鸟类营巢位置可将其分为林冠枝干营巢集团、灌草丛营巢集团、林冠枝干/灌草丛营巢集团、自然洞穴营巢集团、人工建筑营巢集团、自然洞穴/人工建筑营巢集团地面营巢集团、水面营巢集团和寄生集团共9种。进一步分析显示，随城市化程度提高，鸟类营巢集团的数目呈整体下降趋势，而各集团的物种数也基本呈下降趋势。但是，不同的营巢集团对城市化的反应存在差异，导致其物种组成在群落中比例的明显变化。城市化程度的提高使树冠筑巢鸟、灌丛筑巢鸟、地面筑巢鸟及自然洞穴筑巢鸟在群落中所占的比例明显下降，其中地面筑巢鸟最为敏感，灌丛筑巢鸟次之。同时，自然洞穴/人工建筑集团的鸟类在群落中的比例却随着城市化程度的提高明显上升。各营巢集团之所以对城市化做出不同反应，是因为它们对筑巢地资源利用方式不同。此外，还发现植被盖度、人工设施面积、至市中心距离以及人为干扰等因素均可对鸟类营巢集团结构产生影响，但不同类型的营巢集团对上述因素的反应各异。

Effects of Urbanization on the Avian Nesting Guilds in Hangzhou

We investigated the avian nesting guilds in Hangzhou across an urban gradient from March 2007 to August 2007. This gradient includes different urbanization level habitats of urban areas, rural-urban continuum areas, farmland areas, forestland mixed areas, and forestland areas, in order to recognize the effects of urbanization on avian nesting guilds. There were 18 strip transects (3 km×100 m) in each type of habitats, totaling 90 transects. Ninety-six bird species and 9 nesting guilds were recorded. Based on the locations of the nest sites, these were classified as canopy nesters, shrubs nesters, canopy/ shrub nesters, natural cavity nesters, buildings nesters, natural cavity/ buildings nesters, ground nesters, water surface nesters and parasite nesters. The results showed that the urbanization could decrease both the numbers of the nesting guilds and the species in nesting guilds. We found that the urbanization had different impact patterns for different nesting guilds. For example, the number of canopy nesters, shrub nesters, ground nesters and natural cavity nesters declined with increased urbanization. Shrub nesters and ground nesters were particularly more sensitive to urbanization. For the natural cavity/build nesters, numbers were increased with urbanization. The affecting patterns of urbanization were different with different nesting guilds as they using different nest-sites. Additionally, we found that although all of variables of habitat measured in our survey, the vegetation coverage, areas of buildings, distance to the city center and human disturbance could influence the avian community structure of nesting guilds, each variable had a specific pattern of the effect on the nesting guilds separately.