青头潜鸭种群状况及其潜在适宜生境分布

Status and Distribution of Potential Suitable Habitats of Bear’s Pochard Population

极危物种青头潜鸭(Aythya baeri)曾经广泛分布,但是由于其栖息地萎缩或消失等原因,青头潜鸭种群数量急剧减少。通过全国鸟类多样性观测网络、全球生物多样性信息网络、文献查询和咨询专家等方式,共获得2011~2018年期间的318条青头潜鸭分布信息;利用最大熵模型(maximum entropy modeling,MaxEnt)和地理信息系统技术,分析了青头潜鸭繁殖季和越冬季的潜在适宜分布区。研究结果表明,2011年至今,在中国繁殖和越冬的青头潜鸭的种群数量不超过700只,分布在京津冀湖泊湿地、长江中下游流域和环绕黄海、渤海的湿地的青头潜鸭繁殖地和越冬地数量较多,青头潜鸭在其它地区零散分布;利用最大熵模型预测的青头潜鸭繁殖种群和越冬种群潜在适宜生境的AUC(area under the receiving operator curve)值分别为0.982和0.974,表明预测结果可信度较高;青头潜鸭高度依赖低海拔的湿地生境,合适的最湿月的降水量(150~250 mm)、最湿季度的降水量(300~700 mm)和最热季度的降水量(300~600 mm)对青头潜鸭的分布具有主导影响作用;适宜青头潜鸭繁殖种群的生境主要分布在华北平原以北地区和长江中下游的湖泊湿地;适宜青头潜鸭越冬种群的生境主要分布在华北平原和长江中下游平原。

The critically endangered Bear’s Pochard(Aythya baeri)was once widespread and has experienced significant decline in population numbers in the past,as their habitats degradation and disappear.Based on the China-Bon-Birds,Global Biodiversity Information Facility(GBIF),literature search and expertconsulting,a total of 318 items distribution data of the population from 2011 to 2018 were acquired.Maximum entropy modeling(MaxEnt)and ArcGIS software were used to model the potential distribution regions of Bear’s Pochard.The results showed that the population of Bear’s Pochard was less than 700 individuals,and the number of records in Beijing-Tianjin-Hebei areas,the Middle-Lower Yangtze Plain and the coast of Yellow Sea were much more than those in the northeast,and it was scattered in other areas.The AUC(area under the receiving operator curve)values of breeding and wintering model were 0.982 and 0.974 respectively,indicating the prediction of models was accurate.Bear’s Pochard was highly dependent on low elevation and abundant water,and the precipitation of the wettest month(150-250 mm),wettest quarter(300-700 mm)and hottest quarter(300-600 mm)had a dominant influence on the distribution of Bear’s Pochard.The north of the North China Plain was suitable to reproduction of Bear’s Pochard.In winter,the North China plain and the MiddleLower Yangtze plains were the main potential distribution areas of Bear’s Pochard.