This study aims to explore the species composition and climatic drivers of two distinct alpine ecosystems: the High-Latitude Alpine Ecosystems (HLAE) of Hardangervidda National Park, Norway, and the High-Altitude Alpine Ecosystems (HAAE) of the Tibetan Plateau. These ecosystems have variations in environmental factors like solar radiation and topography, but they are characterized by low temperatures, precipitation, and sensitivity to climate change. Data were collected from 40 plots of 100 square meters in each ecosystem, and Non-metric Multidimensional Scaling (NMDS) and Canonical Correspondence Analysis (CCA) were employed to assess species composition and identify key climatic factors influencing these patterns. The results revealed notable differences between the species found in HLAE and those in HAAE. HLAE species were found to be more temperature-sensitive, while HAAE species were found to be more responsive to precipitation. Specifically, Growing Season Length (GSL) and Annual Precipitation (AP) were critical for species composition in HAAE, whereas Mean Temperature of the Warmest Quarter (MTWQ) and Mean Annual Temperature (MAT) were more influential in HLAE. The specific ecological responses of these systems to climate change are discussed, and the study highlights the significance of considering both climatic and non-climatic aspects in understanding species composition in alpine ecosystems.

The evolution of body size, both within and between species, has been long predicted to be influenced by multifarious environmental factors. However, the specific drivers of body size variation have remained difficult to understand because of the wide range of proximate factors that consistently covary with ectotherm body sizes across populations with varying local environmental conditions. Here, we used a widely distributed lizard (Eremias argus) collected from different populations situated across China to assess how climatic conditions and/or available resources at different altitudes shape the geographical patterns of lizard body size across populations. We used body size data from locations differing in altitudes across China to construct linear mixed models to test the relationship between lizard body size and ecological and climate conditions across altitudes. Lizard populations showed significant differences in body size across altitudes. Furthermore, we found that variation in body size among populations was also explained by climatic and seasonal changes along the altitudinal gradient. Specifically, body size decreased with colder and drier environmental conditions at high altitudes, resulting in a reversal of Bergmann’s rule. Limited resources at high altitudes, as measured by net primary productivity, may also constrain body size. Therefore, our study demonstrates that the intraspecific variation in female lizards’ body size may be strongly influenced by multifarious local environments as adaptive plasticity for female organisms to possibly maximise reproductive ecology along geographic clines.