Wider research context / theoretical framework: Anthropogenic destruction of biosphere integrity is rapidly progressing. It even affects remote high mountain regions, questioning their role as biodiversity refuges in times of climate change. Although cold-determined alpine ecosystems are globally distributed, they are often very small-scale and fragmented, so that their disproportionally rich and unique vascular plant diversity is highly threatened through impacts of rising temperatures. This project will use the international GLORIA data set to understand changes in alpine plant diversity in summit zones that have been observed globally since the beginning of this century.

https://gloria.ac.at

Objectives, research questions and hypotheses: By a worldwide compilation of standardised alpine vegetation data and integration of data on ecological drivers, the planned analyses deal with three main research questions and hypotheses: (I) changes in species numbers and composition are related to regional velocities of climate change, (II) combinations of reduced cold stress and increased drought stress accelerates loss of alpine plant diversity and (III) small-ranged species are overrepresented among declining and widespread ones among the gaining plants, being particularly worrisome in isolated small-scale alpine regions.

Approach/methods: We will use (1) data from repeated recordings of permanent plots, distributed over 100 alpine regions of the main mountain systems on Earth, combined with (2) remote sensing data of topography, changes in vegetation greenness and snow cover, (3) in situ-measured soil temperature and gridded climate data series as well as (4) data of species’ overall distribution and their thermic and hydrological niches in order to analyse and assess the magnitude and rates of biodiversity changes in relation to the main drivers.

Level of originality / innovation: This is the first worldwide project on alpine vegetation changes. It is based on the largest systematic sampling scheme of mountain top environments (GLORIA, coordinated in Austria), which has now reached the level of a global resurvey dataset. This coincides with remarkable advances in the availability of Earth observation, climate and species distribution data. This together provides a novel and much improved basis for breaking new grounds in ecological climate impact research on the planet's cold ecosystems.