气候变化领域集成服务门户

As global temperatures rise, there is an urgency to understand the limiting factors of ranges of species and how those factors vary across the range to develop predictions of shifts in spatial distributions. A long-standing hypothesis postulates that, for Northern Hemisphere species, abiotic factors, such as temperature, limit northern or higher elevation extents, while biotic factors like competition limit the southern or lower elevation range edges. Recent evidence, however, suggests that salamanders may follow the opposite of this general trend, although experimental tests of this hypothesis are lacking. Therefore, we determined the role of origin population (i.e., where individuals were captured) and transplant location (i.e., where individuals were placed) on survival, growth, and reproduction using a reciprocal transplant experiment across an elevational gradient with the Northern Gray-cheeked Salamander (Plethodon montanus). We collected juveniles from each of three elevations and transplanted them within mesocosms such that each origin population was represented within each transplant location. We found that individuals transplanted to low elevations had lower survival and growth rates compared to those moved to mid or high elevations regardless of origin location; whereas, individuals originating from low elevations had the highest survival regardless of their transplant location. Our study provides experimental support that conditions found at lower elevations limit the distribution of P. montanus but populations at the lower edge may feature adaptive traits that increase survival. Although climate change is predicted to reduce environmental suitability for this species especially at lower elevations, these traits may be important to mitigating extirpations.