Plant-soil carbon responses to warming and nitrogen - Plant carbon allocation as a mediator of soil carbon dynamics under warming and increasing nitrogen availability.

Soils contain over three times as much carbon as the atmosphere in soil organic matter, and have the potential to slow down or accelerate climate change through altered rates of plant growth and soil organic matter decomposition. Cold, northern ecosystems in particular, store vast amounts of carbon in the soil, but these stocks are vulnerable to increased carbon losses due to warming temperatures and changes in the availability of limiting nutrients such as nitrogen. In addition to the direct effects of warming and increasing nitrogen availability on organic matter decay by microbes, plants also play a major role by changing the way in which they use their photosynthates. By allocating more or less carbon belowground to roots, symbionts, or exudation, plants can alter soil carbon input rates and pathways, and thereby change the way soil organic matter responds to warming and nitrogen enrichment. Our research will examine how warming and nitrogen availability impact on carbon dynamics of plants and soil microbes in order to improve our understanding of plant-soil carbon cycling under future global change scenarios. In order to do this we will carry out experiments in a subarctic grassland of Iceland, tracking carbon flows from plant photosynthesis into the soil and back to the atmosphere and input this data into mathematical models to help better predict ecosystem carbon cycling feedbacks to global warming.

Keywords:SOIL CARBON, CARBON

Disciplines:Ecology, Other environmental sciences, Biogeochemical cycli

Project type:Collaboration project