乐清湾海岛与周边大陆的鸟类多样性及影响因子

Bird Diversity and Their Influencing Factors Between the Islands and the Surrounding Continents in Yueqing Bay

2018年4月至2020年5月,对乐清湾诸海岛及周边大陆开展了鸟类多样性调查,选取其中有代表性的海岛和大陆调查样地各10个,分析二者之间鸟类多样性及其影响因子。结果表明,乐清湾的鸟类多样性岛屿比周边大陆低,其中夏季的多样性指数达到显著性差异(P<0.05),故生境类型差异和隔离程度是主要影响因子;鸟类均匀度指数岛屿高于周边大陆,其中春季的均匀度指数达到显著性差异(P<0.05),则人为干扰是主要的间接影响因子。从β多样性指数看,岛屿与周围大陆之间,种的水平和夏季各自表现出最低的相似性;从生态类群上看,夏季的生态类群物种数存在显著性差异(P<0.05),所以温度是主要影响因子。从个体数看,春季和夏季各有48.39%和61.54%的鸟类存在显著或极显著差异,仅有6种鸟岛屿占优,可能的原因是乐清湾各岛屿仅在多岩石区域和灌丛植被面积占有较大的比率,故各生境面积占比差异是主要影响因子。导致上述差异的主要影响因子包括生境差异(包括生境类型差异和各生境面积占比差异)、人为干扰和温度等,因此乐清湾岛屿比周边大陆具有更大的脆弱性。

The bird diversity survey was carried out on the islands and the surrounding continents in Yueqing Bay from April 2018 to May 2020.10 samples of representative islands and 10 mainland samples were selected to analyze the bird diversity and their influencing factors between them.The results showed that the bird diversity index of island was lower than that of surrounding continent,in which the difference was significant in summer(P<0.05),so the habitat type difference and the degree of isolation are the main influencing factor.The bird evenness index of island was higher than that of surrounding continent,in which the difference was significant in spring(P<0.05),then human interference is a main indirect influencing factor.From theβdiversity index,species levels and summer seasons showed the lowest similarity between islands and surrounding continents respectively,and there were significant differences in summer between the island and the surrounding continent(P<0.05)from the perspective of ecological groups,so temperature is a main influencing factor.Seen from individual number,48.39%and 61.54%of birds had significant or extremely significant differences in spring and summer respectively,and only 6 species of birds were dominated by islands.The possible reason is that the islands only occupy a larger proportion of rocky areas and shrub vegetation than the surrounding continent,so the difference in the area proportion of each habitat is a main influencing factor.The main factors leading to the above differences include habitat differences(difference in habitat type and and the proportion of each habitat area),human disturbance and temperature,so yueqing Bay islands are more vulnerable than the surrounding continents.