Gillies Graydon J, Dungey Michael P, Eckert Christopher G
Department of Biology, Queen's University, Kingston, Ontario, Canada.
Department of Geography, Memorial University of Newfoundland and Labrador, St. John's, Newfoundland and Labrador, Canada.
Ecol Lett. 2025 May;28(5):e70128. doi: 10.1111/ele.70128.
The metapopulation hypothesis for range limits proposes that geographic variation in a species' extinction from and/or colonisation of habitat can generate an abrupt range limit. We tested whether this contributes to the northern range limit of coastal dune plant Camissoniopsis cheiranthifolia by quantifying suitable habitat area and the rates of extinction and colonisation across 3485 plots throughout the northern half of the species' range. Colonisation of previously unoccupied plots increased with suitable habitat area and abundance in nearby plots and consequently declined towards the range limit. Extinction was more frequent from plots with less habitat and lower initial abundance but did not increase significantly towards the limit. Incorporating spatial variation in estimated rates of colonisation and extinction in a metapopulation model predicted a decline in plot occupancy towards the limit that closely matched the observed decline in occupancy. Thus, variation in metapopulation dynamics may contribute to this species' range limit.
关于分布范围界限的集合种群假说提出，物种在栖息地的灭绝和/或定殖的地理变异可产生一个突然的分布范围界限。我们通过量化适宜栖息地面积以及该物种分布范围北半部3485个样地的灭绝率和定殖率，来测试这是否促成了海岸沙丘植物小花山桃草（Camissoniopsis cheiranthifolia）的北部分布范围界限。先前未被占据的样地的定殖随着适宜栖息地面积和附近样地的丰度增加而增加，因此朝着分布范围界限下降。在栖息地较少和初始丰度较低的样地中，灭绝更为频繁，但朝着界限并未显著增加。在集合种群模型中纳入估计的定殖率和灭绝率的空间变异，预测样地占据率朝着界限下降，这与观察到的占据率下降密切匹配。因此，集合种群动态的变异可能促成了该物种的分布范围界限。
