生境因子对向海保护区秋季迁徙期鸟类多样性的影响

Effects of Habitat Factors on Bird Diversity During Autumn Migration in Xianghai Nature Reserve

2016—2018年秋季(9—11月),以定点观测方式布设225个观察点,对吉林向海国家级自然保护区的鸟类进行调查,以ArcGIS 10.3通过导入坐标点的方法将观察点落入3 km×3 km网格中,通过对Landsat 8影像进行监督分类以及对数字高程图(DEM)进行数据提取得到生境因子信息,然后利用ArcGIS 10.3获取各网格的生境因子信息,包括距耕地距离、距林地距离、距水体距离、海拔、坡度、坡向等。利用Excel以及香农-维纳指数、均匀性指数、物种丰富度计算公式将鸟类观测数据转算成鸟类多样性指数等数据,并与生境因子进行相关性分析。结果表明:3年共记录到鸟类57种130597只,数量较集中的有赤膀鸭(Anas strepera,10097只)、灰鹤(Grus grus,15990只)、小天鹅(Cygnus columbianus,10111只)、白骨顶(Fulica atra,13813只)、豆雁(Anser fabalis,35862只)、绿头鸭(Anas platyrhynchos,15096只)等。2016年观测到的鸟类数量大于2017年和2018年观测到的鸟类数量总和。向海保护区内不同地域的生境条件与生境分布的差异导致鸟类多样性在各生境中均有显著差异,其中海拔、坡度、坡向对鸟类多样性的影响较显著,流动沙丘会显著减少鸟类多样性,而林地分布导致其鸟类多样性程度较低但均匀性程度较高;水体内芦苇香蒲沼泽过高的天然盖度对鸟类产生负面影响,导致物种丰富度随着距水体距离的增加先减小后增加;道路与人为用地虽然带来人为干扰因素的增大,但同时增加了生境异质性,特别是使可采食的食物增多,因此物种丰富度反而表现为距离人为干扰越近越大;物种丰富度随着海拔的增大而增大,随着坡度的增加而先增加后减小且鸟类表现出了对固定坡向栖息的倾向性。通过探讨向海保护区内秋季迁徙期鸟类多样性与生境的线性或非线性关系,为向海保护区鸟类保护提供了新的基础数据。

The birds in Xianghai National Nature Reserve of Jilin Province were investigated in the autumns of 2016-2018(September to November of every years).A total of 225 observation sites were set up,and the birds in each observation site were counted by fixed-point observation method.Using ArcGis 10.3 to import coordinate points,the observation points were dropped into the 3 km×3 km grid,and the habitat factor information was obtained by supervised classification of Landsat 8 images and data extraction from DEM(digital elevation map).Then the habitat factor information of each grid was obtained by ArcGIS 10.3,including distance from cultivated land,distance from forest land,distance from water body,elevation,slope,slope direction and so on.Using Excel and Shannon-Wiener index,species evenness index and species richness calculation formula,the data were converted into bird diversity index and the other data,and the correlation with habitat factors was analyzed.The results showed that a total of 130,597 individuals of 57 species were recorded in three years.The more concentrated populations are Anas strepera(10,097 individuals),Grus grus(15,990 individuals),Cygnus columbianus(10,111 individuals),Fulica atra(13,813 individuals),Anser fabalis(35,862 individuals),and Anas platyrhynchos(15,096 individuals).Among them,the number of birds observed in 2016 was greater than the total number in 2017 and 2018.There were significant differences in bird diversity among different habitat conditions and habitat distribution in Xianghai Nature Reserve,and the effects of elevation,slope and slope direction on bird diversity were significant.Among them,mobile sand dunes significantly reduced bird diversity,while woodland distribution led to lower bird diversity but higher evenness,and the high natural coverage of Reed cattail swamp in water body had a negative effect on birds.As a result,the species richness decreased at first and then increased with the increase of the distance from water body.Although roads and construction land bring about the increase of human interference factors,they also increased the habitat heterogeneity,especially the amount of food that can be eaten,so the species richness showed that the nearer the human disturbance is,the greater the species richness is.Species richness increased with the increase of elevation,first increased and then decreased with the increase of slope,and birds tended to inhabit in a fixed slope direction.By discussing the linear or non-linear relationship between bird diversity and habitat during autumn migration,this study provides new basic data for bird protection in Xianghai Nature Reserve.