基于人工掩蔽物法的若尔盖湿地中华蟾蜍种群生态研究

近几十年来,全球两栖动物种群衰减显著,两栖动物的生存现状引起了越来越多的生态学家和保护生物学家的关注。若尔盖湿地不仅是世界上最大的一块高原泥炭沼泽湿地,也是我国生物多样性保护的热点地区之一。该地区分布有3种两栖类:高原林蛙(Rana kukunoris)、倭蛙(Narorana pleskei)和中华蟾蜍岷山亚种(Bufo gargarizans minshanica)。已有研究发现该3种两栖动物种群数量均有不同程度的下降。采用人工掩蔽物法,在2011—2014年对该地区中华蟾蜍种群生态做了连续追踪。结果表明:该区域中华蟾蜍种群数量逐年波动较大,年龄结构数据显示该种群处于增长期;中华蟾蜍为聚集分布,且发现率与水体距离呈显著的线形关系(P0.01),在样地范围内离水体越远,发现的个体越多;线形样方比方形样方捕获动物的效率更高(P=0.018);中华蟾蜍亚成体的肥满度季节间无明显差异;中华蟾蜍具有较强的迁徙能力,可能沿着固定的线路周而复始的迁徙。对于家域范围大,迁徙距离远的中华蟾蜍这类物种,应加强最适栖息地的保护并防止栖息地破碎化。

Population ecology of Bufo gargarizans in zoige wetland based on artificial cover

In recent decades, as the population size of amphibians has significantly declined, the survival status of amphibians has been studied by a growing number of ecologists and conservationists. Zoige wetland is not only the largest plateau peat bog in the world but also one of the biodiversity conservation hotspots in China. Three species of amphibians inhabit this region, Rana kukunoris, Nanorana pleskei, and Bufo gargarizans minshanica. Previous studies showed that the populations of the three species have decreased at different rates. In the present study, we monitored the population ecology of the Asiatic toad (B. gargarizans minshanica) in Zoige wetland using artificial cover from 2011 to 2014. The results showed that:the population fluctuated significantly at the sampling sites; the analysis of age structure showed that the population has been increasing; the number of individuals had an apparent positive linear relationship with the distance from the brook (P<0.01); the number of individuals increased with the distance from the brook; and the line shape was more effective than the square shape in monitoring this species (P=0.018). We also found that the fatness of sub-adults of Asiatic toad did not exhibit significant difference among the seasons. We hypothesize that the Asiatic toad has high migratory capacity, as it may migrate along fixed routes circularly. For those species that have a broad home range and move long distances, such as the Asiatic toad, we should protect the optimal habitats of the species and prevent their fragmentation.