Joel's research interest is mainly green infrastructure and the role of green roofs for the provision of ecosystem services such as stormwater management and biodiversity in built-up areas.
The primary focus of the research is on how different plant compositions affect the ability of green roofs to maintain and delay stormwater volumes at different rainfall intensities and seasons. The research also aims to improve the understanding of how plant communities on green roofs develop over time, especially in challenging climates, and to what extent unintended vegetation (weeds) can contribute with various ecosystem services.
He also studies the relationship between species diversity and biomass on Nordic green roofs and the importance of various abiotic variables as well as weather parameters for plant propagation and survival over time.
Joel has a background as a biologist with a master's degree in biology with a specialization in limnology. His master's thesis was carried out at the Swedish University of Agricultural Sciences (LTU) and dealt with how the size and characteristics of the stream catchments affect the distribution and composition of aquatic plants in dams made of beavers (Castor fiber).