Data from: Landscape-level factors influencing bog turtle persistence and distribution in southeastern New York State

The bog turtle Glyptemys muhlenbergii is a highly endangered species inhabiting freshwater wetlands of the eastern United States. Habitat degradation is considered one of the chief causes of bog turtle declines. Most of the studies investigating habitat requirements of bog turtles focus on intrawetland influences on bog turtle habitat, but few have explored landscape-level drivers of bog turtle distribution. To better understand causes of bog turtle declines, we combined bog turtle occurrence records with geographic data to contrast 12 landscape variables among wetlands containing extant populations of bog turtles (n  =  65) and 500 nearby and 500 distant, randomly located wetlands in southeastern New York State. In contrast to randomly chosen wetlands, bog turtles have persisted in relatively large, open-canopy wetlands (typically >0.42 ha) within large watersheds (typically >13.54 ha), in wetlands with more numerous stream connections, and more often in wetlands positioned atop carbonaceous rock types. Wetlands occurring within carbonaceous surficial geological settings may be more resistant to bog turtle habitat degradation and hence likely to support more persistent populations of bog turtles. Our findings that geomorphic features and intrawetland vegetation are the most useful predictors of bog turtle occurrence and persistence in southeastern New York State are important for generating more detailed hypotheses regarding drivers of bog turtle declines and are also helpful for prioritizing sites for bog turtle conservation and guiding surveys to discover new populations.

牟氏水龟（Glyptemys muhlenbergii）是一种极度濒危物种，栖息于美国东部的淡水湿地中。生境退化被认为是牟氏水龟种群数量下降的主要诱因之一。多数针对牟氏水龟生境需求的研究聚焦于湿地内部对其生境的影响，却鲜有探讨其分布的景观尺度驱动因素。为深入解析牟氏水龟种群下降的成因，本研究将牟氏水龟出现记录与地理数据相结合，对比了纽约州东南部的三类湿地：包含现存牟氏水龟种群的湿地（n=65）、500处邻近随机湿地以及500处远端随机湿地的12项景观变量。与随机选取的湿地相比，牟氏水龟存续的湿地多为大型流域（通常>13.54公顷）内面积较大、冠层开阔的湿地（通常>0.42公顷），且这类湿地的溪流连通性更强，更多分布于碳酸盐岩地层之上。分布于碳酸盐岩表层地质环境中的湿地，对牟氏水龟生境退化的抵御能力更强，因此更有可能支撑存续更久的牟氏水龟种群。本研究发现，地貌特征与湿地内部植被是纽约州东南部牟氏水龟出现与存续的最有效预测因子，这一结果不仅有助于提出关于牟氏水龟种群下降驱动因素的更细致假说，也可为牟氏水龟保护的优先位点筛选以及发现新种群的野外调查提供指导。