Can alpine species take the heat?: Impacts of increased temperatures on early life stages
Climate change threatens plant biodiversity worldwide. Alpine plant species are particularly vulnerable to climate change, as temperature fluctuations are projected to be most severe in high elevation areas. Even small shifts in climate can have major consequences on phenology, reproduction, fitness, and community composition. Early life stages (seed germination and seedling survival) are arguably the most important processes in not only the fitness of an individual plant, but also in the dynamics and persistence of plant populations. These initial developmental stages are expected to be more vulnerable to changes in climate than adult life stages and thereby may represent a major bottleneck to recruitment and population responses as climate change increases in severity. To understand how the early life stages of alpine plant species will respond to warming temperatures, I used climate-controlled incubators at three different temperature regimes. Temperatures were based on current conditions and projected future conditions under moderate and severe scenarios. I found that two rare alpine species, Physaria alpina and Townsendia rothrockii, performed better under warmer conditions as compared to control conditions at both the germination and seedling stage. The results show that early life stages of alpine plants are not at high risk from warming temperatures, however there are many other impacts resulting from climate change beyond temperature alone. Furthermore, it is important to understand the entire life cycle of the species and how conditions may impact plants at later life stages. Future studies aim to tease apart these considerations.