ClimateChange

Many of the most dramatic biological impacts of climate change are mediated by species interactions. Still, we largely ignore how climate change influences the way species interact, and how this affects community dynamics. Due to their steep climatic and ecologic gradients, mountains are excellent systems to study how species interactions will influence community dynamics in future climates. As part of my doctoral research, in collaboration with Loic Pellisier, and Jake Alexander, we transplanted pieces of alpine meadow to lower elevations in the Swiss Alps to investigate how climate change alters the performance of different species and the nature of the interactions among them.

The 2022 Environmental Performance Index is composed of 40 indicators measuring different aspect of environmental sustainability, including trends in greenhouse gas emissions, deforestation, waste management, air quality, etc. Deciding how much each indicator counts towards the overall EPI score involves some subjectivity, and some have criticized the weighting scheme in the 2022 EPI. The EPI website has a tool to modify the relative weights of environmental issue categories and policy objectives, but not the weight of individual indicators.

As climate changes, species’ ability to spatially track suitable climate depends on their capacity to spread (or migrate), a function of their population growth and dispersal capacity. Migration lags can ameliorate the climate experienced at species’ expanding range edges as conditions become increasingly similar to those of the range core. When this boosts species’ growth rates, migrations accelerate. As part of my Ph.D. work, I used simulations of a spreading population with an annual life history to explore the consequences of variation in demography across climatic gradients for the dynamics of climate induced range shifts.