Bioturbation of earthworms in Sweden: impacts of climate and land use

Earthworms play a key role for soil functioning. By moving through the soil, they create new pore spaces, and transport and mix soil.

This activity, termed bioturbation, is of eminent importance for nutrient cycling, carbon turnover, and maintenance of soil structure.

Despite their significant and well-recognized key influence on ecological, hydrological and agronomic soil functions, the amount and seasonal dynamics of bioturbation by earthworms under field conditions remain poorly documented.The overall aim of the proposed project is to quantify the dynamics, rates, and total annual amount of bioturbation by earthworms.

We will monitor bioturbation under field conditions at three different latitudes in Sweden and under two land uses (grassland, arable land), and perform experiments under controlled conditions to obtain bioturbation rates for different species as functions of soil conditions.

Based on these data, we will propose a framework to simulate bioturbation rates, which we will apply to current and future climate.

We hypothesize that bioturbation decreases from south to north, that bioturbation is reduced in arable land, and that climate change decreases bioturbation in the south but increases bioturbation in the north.The project generates quantitative data on bioturbation and develops ways to model bioturbation, which are needed to better quantify the role of earthworms for soil functioning and to value the contribution of earthworms to ecosystem service provision.