Project Details
Projekt
LUMiClim: Interactive effects of land-use and microclimate on drought resistance and their ecophysiological basis in insects
Subject Area
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Term
since 2026
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 569029468
The resilience of ecosystems to climate change is becoming a research field of great importance. There is ample evidence that intense land-use makes ecosystems more vulnerable to climate change and to weather extremes. This is due 1) to impoverished communities, which are less resilient to climatic changes, and 2) to the local microclimate, which is itself affected by land-use and makes communities more sensitive to climate extremes. Intense land-use, such as mowing or intense grazing in grasslands, but also gaps or lack of undergrowth in forests, can lead to drier and warmer microclimates, thus causing higher desiccation stress for insects compared to reduced land-use intensity. In the proposed project, we want to study how land-use affects drought resistance, heat tolerance and cuticular hydrocarbon (CHC) composition in insects. We predict that intense land-use acts as environmental filter, which only drought-resistant and heat-tolerant species survive. Since drought stress increases with temperature (even well below lethal temperatures), drought resistance may be an important driver of insect species distribution. Insects protect themselves against desiccation with a waxy layer of cuticular hydrocarbons (CHCs) that cover their cuticle. Their composition is highly species-specific. Certain CHC traits are strong indicators of the drought resistance a CHC layer can provide. For example, CHC layers provide better drought resistance if they have high proportions of n-alkanes, low proportions of alkenes, and/or longer hydrocarbon molecules (high chain lengths). Here, we want to sample six insect taxa, hoverflies, wild bees, true bugs, Orthopterans (grasshoppers and others), ants, and dung beetles, which differ in ecological function and micro-habitat. Our aim is to determine how their distribution along a land-use gradient can be explained by drought resistance, heat tolerance, and CHC composition. They will be collected via sweep-netting (bees, hoverflies), sweep-netting and beating trays (Orthoptera, true bugs), or baited traps (ants, dung beetles). From each taxon, we will collect 8 to 20 species, and determine drought resistance, heat tolerance (CTmax), and CHC profile. For rarer species, we will only collect CHC samples. This will be done in REX I and in FOX sites of the Biodiversity Exploratories, as we expect mowing (REX) and gaps (FOX) to have particularly strong impacts on drought stress for insects. Our data will allow us to understand how CHC profiles, but also drought resistance and heat tolerance, can be used to predict a species’ tolerance to intense land-use and to climatic extremes. The interactive effect of land-use and climate on biodiversity, species distributions, and resilience is a focus of the current funding phase of the Exploratories. Our project aims at a mechanistic understanding of the link between ecophysiological functional traits, climate, and land-use intensity, and will hence be a valuable contribution to this goal.
DFG Programme
Infrastructure Priority Programmes
Subproject of
SPP 1374:
Biodiversity Exploratories
