The role of intraspecific variation in seed dispersal, traits, and genetic diversity for the response capacity of plants to climate change

• Applicant: Dr. Eike Lena Neuschulz
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 264526707

Four potential responses of species to climate change exist: species could tolerate the changing conditions and persist, they could shift to alternative habitats, they could move to their preferred habitat, or they could go extinct. Which of these options may apply to a particular species depends on its response capacity mediated by various components, such as dispersal and colonization ability, life history traits and genetic diversity. While previous studies have mainly investigated the mean differences among species in response to climate change, we know only little on how variation among individuals shapes species’ response capacity across distributional ranges. I here propose to use the Swiss stone pine (Pinus cembra) and its seed dispersing bird, the Spotted nutcracker (Nucifraga caryocatactes), as a model system to examine how intraspecific variation in a) dispersal ability, b) reproductive traits and c) population genetics in concert with local environmental conditions affect the recruitment of the plant across its elevational range. In particular, I aim to examine how these components shape the plant’s response capacity, defined as the ability to successfully recruit at high elevations. In the first work package, GPS tracking of nutcrackers will be conducted to study variation in pine seed dispersal across three range positions (i.e., at the population center, and at the upper and lower elevational range edges). I will identify foraging and seed caching sites and the frequency of movements between them to study whether and how often birds move seeds upwards, downwards or within the respective range position. In the second work package, I seek to conduct seed transplant experiments, where large- and small-sized seeds from each range position are sown at all three range positions to test how seed size in concert with the genetic diversity of seed source populations and local environmental factors affect pine establishment. In the third work package, data from work package one and two will be used to calculate the response capacity of Swiss stone pine to climate change. I will assess the recruitment probability, i.e. the potential to successfully disperse and establish across the elevational range of the species. I will then calculate the response capacity to climate change as the probability to recruit beyond the current population center. Taken together, this approach will unravel intraspecific variation in seed dispersal, seedling establishment and genetic diversity to better understand the mechanisms that allow plants to recruit at high elevations. This way, the planned study will advance current research efforts to better understand the capacity of species to respond to climate change.

• DFG Programme: Research Grants