This Masters Project uses a laboratory experiment, paleolimnological approach, and monitoring data to identify specific mechanisms driving species acclimation to warming. More specifically, we study intraspecific phenotypic plasticity of aquatic invertebrates (with Chironomidae as model organisms) in response to climate warming.
Climate warming has been identified as one of the most important and immediate threats to biodiversity. Among others, individuals can persist under novel climates by acclimation through a series of changes across organisation levels allowing species to cope with temperature changes. Climatically driven phenotypic variation among populations is a common feature for aquatic invertebrates, but there is no universal agreement. For example, although decreasing body size in response to climate warming is expected to be widespread, this finding may vary across organismal groups.
Furthermore, climate fluctuates at various magnitudes and rates of change, but the influence of these climate characteristics on acclimation has been largely overlooked (i.e. high magnitude of climatic change can exceed the physiological limits of an organism, and, therefore, hinder species' abilities to acclimate to novel conditions). Although acclimation processes are key to our understanding of biodiversity responses to climate warming, they have, unfortunately, not been extensively studied.
We will chironomid larvae as model organisms. Chironomidae (Arthropoda; Diptera; Nematocera) are one of the most diverse and abundant group in lakes, forming keystone taxonomic groups in lake food web. Chironomid larvae also produce remains that preserve well in lake sediments, and microscope-based identification of these subfossil remains to the species level provides unique insights into climate-induced changes in chironomid biodiversity.
Intraspecific phenotypic plasticity will be quantified using measurements of the different morphological parts of the head capsule of chironomids (i.e. mentum, ventromental plate, mandibles). This will allow producing time series of morphological changes.
Depending on your own interest, we will use biological samples from rearing laboratory experiments, paleolimnological records of the Late-Glacial period, and from the Swedish monitoring program.
This objective will unravel the specific mechanisms driving species acclimation to warming. Previous theories showing body-size distribution will find novel support here. We expect that results can be published in a high-ranked scientific journal (with you as a co-author).