Description of research and teaching

Main Interest

My main research interest is the effects of our everyday urban activities on ecosystem processes and health. I am in charge of the ecosystem research consortium ADELE - Immune Defense and Living environment funded by Business Finland. The projects aims to reveal previously hidden associations between biological diversity, environmental pollution and land cover, and we develop novel ways to modulate immune response among urban dwellers. My other projects include ImmunoGarden that seeks for ways to ameliorate biodiversity in the everyday living environment of urbanites. The other research groups in ADELE consortium are Professor Heikki Hyöty's virology group and Professor Juho Rajaniemi's urban planning group at Tampere University. We employ scientists from several disciplines, e.g. architecture, ecology, geography, medicine, molecular biology, social sciences. One of the central goals is to utilize cross-disciplinary metadata to reveal novel associations between living environment and health. I am collaborating with Principal Investigators at DIPP (Diabetes Prediction and Prevention; Professor Mikael Knipp at University of Helsinki, Professors Jorma Ilonen and Jorma Toppari at University of Turku and Professor Riitta Veijola at University of Oulu) and Ikihyvä (Good Ageing in Lahti region) projects as well as Professor Ari Jumpponen (Kansas State University) and University Lecturer Raisa Valve (Department of Food and Environmental Sciences at UH). The ADELE consortium seeks for practical solutions that are widely acceptable; we have close connections to several enterprises and Helsinki Innovation Services.

Soil, microbes and plants

My long-term research interests cover the impacts of pollution on microbial communities and plant growth, soil remediation and the ecology of autumn leaf colors.  My Ph. D. thesis consisted of five single-author papers that concentrated on the effect of phytotoxins on plant biomass at varying plant densities (Sinkkonen 2001 J. Chem. Ecol., 2003 Plant Soil, 2006 Dose-Response, 2006 Springer book chapter, 2007 J. Theor. Biol.). Thereafter I was lucky to meet Professor Martin Romantschuk who introduced me to the fascinating realm of soil remediation and the ecology of soil microbial communities (e.g. Kauppi et al. 2011 Intern. Biodet. Biodegr., 2012 Environ. Sci. Pollut. Res., Sinkkonen et al. 2013 Environ. Sci. Pollut. Res., Yu et al. 2014 J. Environ. Manag., 2015 Appl. Soil Ecol.). University Lecturer Anna-Lea Rantalainen provided invaluable expertize when I realized that low toxicant concentrations can shape plant populations even though mean size is not affected (Sinkkonen et al. 2008 Environ. Pollut., 2009 Sci. Tot. Environ., 2011 Dose-Reponse). Today, this research direction continues in collaboration with Ph D Regina Belz (Universität Hohenheim; Belz and et al. 2018 Sci. Tot. Environ.). Together with Professor Jeffrey D. Weidenhamer (Ashland University), I have been exploring the consequences of density-dependence of pollutant effects on plants (Hansi et al. 2014 Environ. Pollut.). I have worked also with plant invasiveness, in collaboration with Professor Heikki Setälä and group leader Vesa Hytönen (University of Tampere)(Sinkkonen et al. 2014 Soil Biol. Biochem), and Professors Kitichate Sridith and Krittika Kaewchumnong at Prince of Songkla University (Thapa et al. 2017 Weed Research).

Autumn leaf colors

Autumn leaf colors belong to the most impressive displays in nature. As they may play a central role in tree growth and defense, I investigated them in spare time. I found out that early leaf yellowing is associated with high seed production in mountain birch (Sinkkonen 2006 J. Evol. Biol.). Professor Simcha Lev-Yadun (University of Haifa) and I got independently the idea that red spring leaf colors and red autumn leaf colors have separate evolutionary histories, and we published a geographically wide survey of leaf coloration (Lev-Yadun et al. 2012 Flora). University Lecturer Juha Mikola had a central role while we found out that leaf yellowing affects aphid load on silver birch (Sinkkonen et al. 2012 New Phytol.). At the same time, I realized that the egg load of birch aphids may depend on growth cessation (Silfver et al. 2015 Evol. Ecol.). My experimental and observational research does not provide direct support for the most cited hypotheses concerning the evolutionary ecology of autumn leaf coloration. Instead, I believe several interrelated factors have shaped leaf cessation in boreal and temperate regions.

Team members and collaboration

I am the head of the Nature-Based Solutions Research Group at the University of Helsinki. The team members include Dr. Riikka Puhakka, Dr. Mira Grönroos, Dr. Anirudra Parajuli and graduate students Marja Roslund, Laura Soininen, Yan Sun and Guoyong Yan. B. Sc. Simone Cavazzoli and B. Sc. Alexis Haskins belong to Erasmus and Fullbright trainees in 2019. I have also supervised several Ph. D. and M. Sc. theses:

Ph. D. Sari Kauppi (2007 - 2011) Title: Bioremediation of diesel oil contaminated soil and water, University of Helsinki (cosupervisors Martin Romantschuk and Rauni Strömmer);

Ph. D. Lal B. Thapa (2013 - 2016) Title: Impacts of invasive alien species on native vegetation in Central Nepal, Prince of Songkla University, Hat Yai, Thailand (cosupervisor Kitichate Sridith);

Ph. D. Anirudra Parajuli (2015-2019) Title: The effect of living environment and environmental exposure on the composition of microbial community in soil, on human skin and in the gut. University of Helsinki, University of Helsinki (cosupervisor Anna-Lea Rantalainen)

M. Sc. theses: Anne Kemppainen (2010), Mervi Myyrä (2010), Eeva Somerkoski (2010), Minna Vesterinen (2011), Mari Hansi (2011), Helena Rahikainen (2012), Yun Xiao (2015) , Yan Sun (2016), Marja Roslund (2017), Ruhui Wen (2017), Heli K. Vari (2017)

Dr. Olli Laitinen (one of the key scientists in ADELE; Tampere University) belongs to key collaborators since 90's. I have collaboration also with Senior Researcher Pertti Pulkkinen (Natural Resources Institute Finland), Dr. Tomasz Płociniczak (Uniwersytet Śląski w Katowicach; Płociniczak et al. 2013 Appl Soil Ecol.), Dr. Sergio Sorbo (Universita' degli Studi di Napoli Federico II; Sorbo et al. 2011 Plant Biosyst.) and Professors Polina Galitskaya and Svetlana Selivanovskaya at Kazan Federal State University.

Former group members include Assoc. Prof. Nan Hui at Shanghai Jiao Tong University and Ph. D. Ville Selonen who is CSO at Remsoil, a soil remediation company that utilizes a patent based on one of the innovations in the Nature-Based Solutions Research Group (Liu et al. 2019 Chemosphere).