Contact: Changyi Lu (changyi.lu@helsinki.fi), Heikki Setälä (heikki.setala@helsinki.fi)

Our previous research has shown that soils under trees, especially evergreen trees, have a high capacity to store carbon and nitrogen in urban greenspaces in Helsinki and Lahti. However, the area upon which scattered park trees extend their impact of root in urban parks remains unknown. This information is important when evaluating the ability of urban greenspace to mitigate climate warming. This study gives a Master’s student a compact pro gradu entity to be completed together with the researchers of our Urban Ecosystems Research Group.

Contact: Pasi Pouta (pasi.pouta@helsinki.fi), Johan Kotze (johan.kotze@helsinki.fi)

The main aim of this project is to identify the main factors driving and filtering vascular plant biodiversity in urban novel grasslands, such as road verges, wastelands and extensively managed open-vegetated green areas. These factors vary from local conditions, such as soil type and management, to landscape-scale factors, including current and historical habitat connectivity. As a Master’s student, you can focus for example on the community structure and biodiversity measures in one novel grassland type, and gathering data in Helsinki during the summer of 2021.

Contact: Johan Kotze (johan.kotze@helsinki.fi), Heikki Setälä (heikki.setala@helsinki.fi)

Urban forests experience chronic disturbances including trampling and understorey management, resulting in a simplified structure at ground level. Yet, small-scale within-site heterogeneity does exist in these forests, including piles of dead and decaying wood, boggy areas and spots with lush vegetation. The purpose of this study is to investigate the response of an indicator taxon, carabid beetles, to this small-scale heterogeneity, both from a taxonomic and functional trait perspective. The data collected will help to identify natural features in these highly used urban forests for conservation purposes. Sampling will be performed in a number of urban forest remnants in the city of Lahti in the spring and possibly the summer in 2021.

Contact: John Allen (john.allen@helsinki.fi), Heikki Setälä (heikki.setala@helsinki.fi), Johan Kotze (johan.kotze@helsinki.fi), Riikka Järvinen (riikka.a.jarvinen@helsinki.fi)

Mineralization of organic N and nitrification of ammonia in the soil are mediated by soil bacteria. Dogs have been shown to be a major source of N in urban parks via their urine (dog-deposition), and to have significant impacts on soil chemistry and microbial community structure. The purpose of this study is to compare and contrast N mineralization and nitrification (NMN) rates in soils from urban parks, which are commonly visited by urban residents and their dogs, with those in urban cemeteries, which are similar environments but exclude dogs. The chronic and highly localized nature of dog-deposition is expected to give rise to extreme differences in NMN rates between these two types of urban greenspace. In this study, three rounds of soil sampling will be conducted during the spring, summer, and autumn of 2021, from around path-side trees and poles in urban parks and cemeteries in Helsinki and Lahti.