Existing research indicates that warming can have a negative effect on richness and abundance of microarthropods, and cause a shift in community structure, while nutrient enrichment can increase microarthropod abundance with concurrent shifts on the community composition. Here, I examine whether warming and nutrient levels affect microarthropod abundance, richness and community structure through bottom-up shifts in the microbial community. My overall object is to examine the effects of soil warming on the soil microbial and microarthropod community in two peatland sites that differ in nutrient status. This work is in collaboration with the Ontario Forest Research Institute.
Ongoing climate change is expected to increase global temperatures between 2 and 8°C over the next century with the most extreme warming in the northern latitudes, as atmospheric CO2 concentrations are projected to reach 800 ppm. Here I examine the individual and interactive effects of warming and CO2 . My objective is to identify trends in peatland microarthropod communities under a range of soil warming treatments (ambient, +2.2, +4.5, +6.7, and +9°C) and under elevated CO2. This work is in collaboration with the U.S. Dept. of Energy SPRUCE experiment in Minnesota.
Food webs models provide information on a system’s biochemical processes, biodiversity, complexity, and potential stability. Because parameterizing a basic soil food webs requires collaborations among many specialists, we have very few examples that provide information on rates of energy and nutrient flow for real ecosystems. There are no published examples for peatland sites in Canada. Here, my objective is to create an energy-flux model for two peatland sites differing in nutrient status.
Microplastics are defined as plastic particles that are <5mm. Manufactured in the production of many commercial products, microplastics have become an environmental threat for many organisms. Microplastics can be highly abundant in soil, and given their size, can interact with soil microarthropods. But how microplastics affect soil-dwelling organisms (mites and collembolans) and their role in ecosystem services such as decomposition is largely unknown. Here, we use polyester and polypropylene microfibers in two different lengths to determine whether microplastic addition have effects on litter decomposition rates, soil fauna feeding rates, and soil microarthropod community structure.
Fungal and bacterial energy pathways in detrital food webs are linked by predators at the top of the food chain that exert top-down control on lower trophic levels. While warming is predicted to enhance the abundance of lower trophic level species, warming is expected to have a negative effect on higher trophic level and larger bodied species because of increased metabolic costs. Both top-down and bottom-up processes structure food webs, however it is unknown what the relative balance of these two processes will be under climate warming. My goal is to experimentally test whether top-down (predator) and bottom-up (nutrient) processes are moderated or altered by warming using a novel experimental soil system.