Functional ecology of the alpine cryptogamosphere in the face of change

Cryptogams (mosses, lichens) are a conspicuous part of the ecology of alpine and higher-latitude ecosystems, and are important for cycling carbon and nutrients. In particular, how cryptogams take nitrogen from the atmosphere (N-fixation), could be of considerable importance in these systems, where nutrients are generally not easily accessible by plants and microbes. Our understanding on these processes is poor, especially in the alpine, and especially for times of the year outside of the main summer growing season. This is concerning given how climate change is disproportionally effecting higher latitude, higher elevation, ecosystems, and through changing snow-cover, affecting winter strongly. This also means that understanding the role cryptogams plays in global climate modelling is not well resolved, and in ecosystem where they are abundant, this is a shortcoming. Cryptogams also have a diverse microbial community inhabiting the aboveground parts. As part of a complex microbial food web, this includes photosynthesising organisms and microbes that can fix atmospheric nitrogen. Currently, we have little information on the molecular ecology of these communities, and if the structure and function of the microbe-cryptogam system varies over time, and amongst different cryptogams. To understand this, and how alpine cryptogams function over time and in response to changing energy and nutrient availability, we will study four different species of cryptogams in our fieldsite in the Cairngorms of eastern Scotland. In this sub-arctic alpine environment, we will measure how C and N are captured and cycled by cryptogams, measure for the first time how these processes occur under snow, and track the fate of C and N into soils. We will use shading methods to change how C enters to the system, allowing us to determine how cryptogams change their nutrient cycling under altered energy availability. Together, these investigations will help us better model how these ecosystems under a changing climate, and increase our understanding of the ecology of the cryptogamosphere.