Project: The potential of trees to mitigate climate change in northern arable lands

Duration: 2019–2020

Team: Liisa Kulmala (Finnish Meteorological Institute), Karoliina Huusko (University of Helsinki), Kristiina Karhu (University of Helsinki), Mari Pihlatie (University of Helsinki)

Funded by: Tiina and Antti Herlin Foundation

Short description:

Agroforestry is a very marginal practice in Northern countries currently and it is not even favored by current subsidies or policies. However, in the tropics, agroforestry has proved to be an excellent method not only for mitigating climate change but also for improving yields due to increased biodiversity and soil carbon.

The objectives of this project were

(1) to evaluate the potential of tree avenues planted in croplands to uptake atmospheric carbon and also nitrogen in Finland

(2) to quantify the effect of trees on yields and the amount of nitrogen available in the soil.

The measuring site was located at Kilpiä Farm, Pusula, southern Finland. In the summer of 2019, the trees had an average height of 3 m. The measurements are made in several cross-sections on both sides of the tree avenues at distances of 0-12 meters. In addition to regular greenhouse gas exchange measurements over the growing season, we studied the effect of the trees on plant growth, i.e. biomass production, soil moisture and temperature, pH, pool and quality of carbon and nitrogen, microbial biomass and microbial species at different distances from the tree avenues.