Abiotic stress alters microclimate by changing vegetation traits

• Applicants: Professor Dr. Christian Bernhofer, since 1/2024; Professorin Dr. Jutta Ludwig-Müller, since 3/2023
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 449763414

The preservation of biodiversity and endangered habitats is a global priority. A key limitation for this task is the difficulty to identify in advance which goals are currently attainable in a given target area, and what will be the sustainability of our achievements over time in the face of climate change. The assessment of the microclimatic niche of a target vegetation type is a key step, because the microclimate is the actual conditions experienced by the plants. A major gap in our understanding of microclimate formation is the range to which microclimate is shaped by the vegetation, especially under stressful conditions. We hypothesize that the microclimatic niche of a vegetation type is determined by the capacity of the dominant species to buffer climatic fluctuations and by shifts in species and functional groups abundancies. In the proposed study, we will quantify the vegetation’s microclimate modification capacity (VMMCa), specifically under drought and heat stress, and assess the level to which stress mitigation is reliant on microclimate modification.The study will take place in the Ore Mountains and focuses on species-rich montane meadows (Polygono-Trisetium) as a representative of temperate grassland vegetation, an ecosystem experiencing globally the highest rates of habitat loss. Our specific goals are: (1) detecting shifts in traits of dominant species and in the characteristics of the plant community along microclimatic gradients, and in turn, how these shifts alter the microclimate, (2) assessing the thresholds for a change in plant’s resource allocation in response to drought and heat stress in order to anticipate how plant reaction to stress will influence microclimate and species composition in the community, and (3) quantifying VMMCa of a plant community in field setting and on a broad spatial scale to develop a novel approach for the assessment of community vulnerability to climate change. Finally, we will conduct a synthesis on whether the capacity to mitigate stress is the same as the capacity to alter the microclimate. To achieve these goals we will perform substantial amount of fieldwork in the form of vegetation surveys, manipulation experiments, and physiological measurements while at the same time operating a dense network of sensors to monitor the microclimate in the study plots. Additional climatic and microclimatic variables beyond those measured in the field will be derived through regional datasets, remote sensing and modelling. The outcome of the project will enhance the mechanistic understanding of how microclimate is formed as an interplay between biotic and abiotic factors, and enhance the mechanistic understanding of plant stress in complex environments.

• DFG Programme: Research Grants
• Ehemalige Antragstellerinnen / Ehemalige Antragsteller: Daniel Gliksman, Ph.D., until 12/2023; Dr. Sabine Hänel, until 3/2023