Most evidence for links between plant traits and soil microbial communities comes from small-scale studies. We found that across 180 English grasslands, plant traits explained a significant amount of variation in soil microbial community composition, and specifically, that plant traits associated with conservative growth strategies were linked to fungal-dominated microbial communities.

Manipulative experiments in subtropical plantation and orchard systems showed that understory vegetation plays an important role in driving the ecological processes and functions of Eucalyptus plantations, such as soil respiration, litter decomposition and soil microbial community composition. Maintaining a living understory vegetation has great soil carbon sequestration potential in subtropical orchard systems.

Wind farms affect the local climate as they remove energy and increase turbulence. Given that both gas fluxes and dissolved organic carbon concentrations are significantly controlled by temperature and water table depth, a wind turbine – induced microclimate may significantly affect the carbon budgets of peatlands. In this paper we present data from Black Law Windfarm, Scotland.

We compared the functional traits of green leaves and leaf, twig and wood litters among 27 co-occurring tree species, and quantified the decomposability of the three litter types.We tested for coordination in the relative litter quality and decomposition across the three litter types, and identified the functional traits most closely associated with the decomposition of leaves, twigs and wood.

Previous studies have reported significant differences in the performance of above-ground herbivores and parasitoids on different populations of wild cabbage growing along the Dorset (UK) coast. Here, we find only subtle effects of plant-related differences in quality on a root herbivore. Potential interactions between root and shoot herbivores in this system are explored.

Positive bi-directional feeding facilitation, where both herbivores benefit by each other’s presence, is rare. Here we present evidence for this phenomena between a herbivore feeding aboveground (an aphid) and belowground (vine weevil larvae). Although spatially separated, these herbivores interact via changes in plant chemistry. We show this can prove beneficial to both insects at the expense of the plant.

Increased nitrogen availability is believed to suppress decomposition and hence promote ecosystem carbon sequestration, but this largely stems from studies applying nitrogen at rates orders of magnitude higher than current or likely future ambient nitrogen deposition. We show that this assumption may be flawed by demonstrating opposing responses of soil respiration to different nitrogen levels in a subarctic pine forest. 

The plant-mediated interactions between aboveground and belowground herbivores have attracted more and more attention. Our research mainly focus on interactions between aboveground and belowground herbivores of Plantago lanceolata. A greenhouse experiment was conducted to investigate how genetic variation in plant defense between P.lanceolata lines affects performance of aboveground herbivores, belowground nematodes and their interactions, via influencing defense compounds in plant.

Plant traits can influence the soil microbial community through their influence on the quantity and quality of organic carbon inputs to soil. We present results from cross site mesocosm and field experiments aimed at identifying how plant traits, both aboveground and belowground, impact on microbial communities of grassland soil.  

Ecosystem management can impact soil carbon stocks, but threshold levels are rarely known and in highly variable systems, threshold levels can alter.  A survey of twenty-two salt marshes showed grazing effects on aboveground plant properties, but no effect on belowground carbon stocks.  The study demonstrates grazing has a weak broad-scale effect on carbon storing in comparison to environmental variation.

Negative plant-soil feedback (PSF) plants are expected to grow better in diverse plant communities relative to monocultures, potentially driving positive biodiversity-productivity relationships observed in biodiversity experiments. However,  negative PSF species also tend to remain subordinate in plant communities. We find the latter aspect to be deciding: ‘neutral’ PSF species dominate productivity while outcompeting negative PSF plants in diverse plant communities.

Biotic exchange, and the spread of invasive plant species, has been identified as a major agent of biodiversity loss and environmental change. Some invasives also alter key ecosystem processes such as nitrogen cycling. Focussing on three problematic invasive species in Ireland, we compare nutrient cycling and decomposition processes in invaded and native communities.

This talk shall present results from the Peak District, United Kingdom, looking into the role that soil organic matter quality may have in constraining the explanations of changes in carbon flux across the hillslope. One metre soil cores were analysed for CHNO content, energy content and thermal weight loss; indicating significant changes in organic matter quality across the hillslope.

We measured Sphagnum traits across a range of species and habitats, and examined scaling of traits with canopy variables. Two trait trade-offs emerged. Individual metabolic rate and capitulum size decreased with height above water table, whereas photosynthetic efficiency decreased from treed to open habitats. Rates of production, height growth and litter decomposition scaled with Sphagnum traits.

Email: L.Belyea@qmul.ac.uk