黑嘴鸥巢址的时空变化

Spatiotemporal variation of nesting sites of the Saunders's gull Larus saundersi

利用Arcview GIS对江苏盐城国家级自然保护区1999-2007年黑嘴鸥的巢址时空变化研究结果表明:区域尺度上,江苏盐城沿海黑嘴鸥种群数量维持在1000只左右,多年平均为954只±161.26只,但由于滩涂围垦和开发,其营巢地主要集中在核心区,种群数量占整个种群数量的85.24%±7.00%。地点尺度上,中路港巢区的多年平均面积为153.19hm2±112.09hm2,三里闸巢区的多年平均面积为62.60hm2±66.41hm2;两个巢区的质心总体上均向东南方向偏移,中路港巢区与潮沟大泗洋子距离以及三里闸巢区与潮沟大流水距离均呈现减小趋势;但同一巢区不同年份的重叠面积、密度和质心均不尽相同。影响黑嘴鸥巢区时空变化的因素包括年际间降雨量、潮水的入侵、植被演替等自然因素,同时还包括无序开发利用滩涂生物资源、拾捡鸟蛋、人为改变滩涂水动力等人为因素。鉴于此,提出了江苏盐城沿海黑嘴鸥及其栖息地的保护管理建议。

Understanding spatial and temporal patterns of species is a prerequisite for successful species and habitat conservation. Spatiotemporal variation of nesting sites of Sannders＇s gull Larus saundersi was studied in Yancheng National Nature Reserve from 1999 to 2007. In terms of regional scale, the population size was maintained at 1000 individuals in recent years （954 ± 161.26） . With greater land reclamation along the coastline, the nesting areas tended to shift to the core area gradually and accounted for 85.24 % ± 7.00% of the total population. In terms of site scale, mean nesting areas among different years reached 153.19 hm^2 ＋ 112.09 hm^2 in Zhonglugang and 62.60 hm^2 ＋ 66.41 hm^2 in Sanlizha. The overlapped area, density and centriod of the same nesting area in different years showed distinct difference. However, the centrieds of different nesting areas tend to the southeast. The distances between nesting sites and the tidal channel of Dasiyangzi, and Daliushui in different nesting areas showed decrease. Factors affected the spatiotemporal variation of nesting areas of Saunders＇ s Gull include natural constraints such as rainfall, tide and vegetation succession, and artificial factors such as grass and clamworm harvesting, egg-collection, and other human disturbances. Considering the differences of site tenacity and spatial turnover in different scales, we also propose measures for conserving the Sannders＇s gull and its habitat