High elevation wetlands and global changes: Impacts on biodiversity and ecosystem services

Background/Question/Methods: One promising approach to study the integrated effects of global changes on biodiversity and on ecosystem services involves monitoring the responses of entire ecosystems, as they may represent sensitive indicators of both drivers and responses. High-altitude wetlands (above 3000 m) represent ideal sentinels of global changes as their dynamics is tightly connected to climate-related changes (e.g. glacier melting rates, change in precipitation patterns) and the use of the numerous ecosystem services they provide to humans (e.g., water yield, fodder). Yet, to date, we have no broad-scale overview on the relevance of high-altitude wetlands (made by both plant and aquatic communities) as potential ‘ecosystem sentinels’. We addressed this issue through a worldwide literature review of > 500 publications on high-altitude wetlands' biodiversity and ecosystem services. We also analysed the world database of high altitude wetlands protected by the Ramsar Convention (https://rsis.ramsar.org/).

Results/Conclusions: The literature review revealed that livestock farming and ranching, water use and flow modifications, mining and climate extremes were the four main threats affecting the integrity of high altitude wetlands. Of the 2,245 RAMSAR sites covering 2,149,907 km² over the world 35 (1.5%), covering 50,842 km² (2.3%) laid completely over 3000 m. A comparison of Ramsar protection criteria between high altitude and low altitude wetlands (< 3000 m) revealed interesting attributes of the former in terms of ecosystem sentinel potential. High altitude wetlands were recognised as being unique ecosystems, sheltering endangered species and supporting the population of important plant and animal species (in particular birds populations) at significantly higher frequency than their lowland counterparts. There results argue in favour of the use of high altitude wetlands as ecosystem sentinel of global change. Based on both literature survey and analyses, we propose a general conceptual framework for a sustainable management and conservation of biodiversity and ecosystem services of high altitude wetlands in the face of global changes. This framework builds upon the classical drivers–pressures–state–impact–response model that links scientific findings with real world issues, thereby favouring science-based resource management decisions.