The disappearing cryosphere in the Rocky Mountains: Tipping points and ecosystem responses to changes in mountain climate

Background/Question/Methods

Niwot Ridge in the Colorado Rocky Mountains is the only multidisciplinary, long-term field site for high-elevation areas on the North American continent. As such, the site is an essential benchmark for regional, national, and global networks that measure biological changes and feedbacks and experimentally determine mechanisms for these relationships. Our ongoing attempts to meet the challenge of converting long term monitoring into process-based understanding on the controls of biodiversity and ecosystem processes at the NWT LTER is shaped by the interface of two conceptual models a) the Landscape Continuum Model and b) the novel ecosystems concept that arises out of the Panarchy Model. The interplay of these two models argues that amplification of drivers such as climate change, N deposition, and dust deposition in high-elevation catchments may be “tipping” these ecosystems into states not experienced in modern times.  
Results/Conclusions
I’ll illustrate these ideas with the following items: a) evaluate the quality and quantity of organic carbon deposition to high-elevation landscapes, b) test how plant-soil feedbacks and directional environmental change influence community dynamics, extending previously developed theory on threshold effects or tipping points to alpine ecosystems, c) evaluate the potential of biotic disturbances such as species invasions and infectious diseases to tip ecosystem properties and dynamics into novel ecosystems in both terrestrial and aquatic environments, d) build on a new conceptual framework and global meta-analysis to test the ways in which a stoichiometric perspective may better predict N accumulation along the hydrologic continuum both within and beyond the NWT region, e) explore ecohydrological feedbacks over the NWT LTER and the surrounding region through the next century by improved synthesis, integration and model development, and (f) work with social scientists and economists to increase our understanding of the impact of these and other perturbations such as the mountain pine beetle invasion and increased fire frequency on ecosystem services in high-elevation areas.