Johanna Toivonen de Gonzales profile picture
Toivonen de Gonzales
Senior Researcher, Biodiversity Unit of the University of Turku


+358 29 450 3652
+358 50 595 1495
Vesilinnantie 5

Areas of expertise

Treeline spatial patterns and dynamics
Tree biomass and carbon fluxes


I am a plant ecologist fascinated by biogeography, with research experience from variety of vegetation and climatic zone, from humid tropics to subarctic and dry savanna environments.

I did my MSc in 2002 on tropical low land forest structure, dynamics and seed dispersal in Peruvian Amazonia at the Department of Biology, University of Turku. Main subject: Ecology. Minor subjects: Taxonomy and Environmental sciences.

I defended my PhD in 2014 at the Biodiversity unit of the University of Turku. My dissertation on “Determinants of Polylepis (Rosaceae) forest distribution and treeline formation in the high Andes” dealt with ecology of high-Andean endangered Polylepis treeline forests, and climatic & anthropogenic impacts on them.

Currently my work focuses on carbon stock and fluxes of African dry savanna environment trees.


I have assisted as a co-teacher in several field courses and excursions, for example: Excursion to New Zealand in 2020 by the University of Marburg, and Erasmus BIP (Blended Intensive Programme) course on the vegetation patterns in altitudinal and latitudinal gradients (2023), co-organised with the University if Marburg, University of Turku and University of Réunion. The physical parts were held in Kevo biological station in N-Finland and in the topical island of La Réunion. Erasmus BIP courses are a new element of Erasmus+ programme, offering a new and flexible way for student and staff mobilities combining innovatively physical and virtual teaching & learning.

I have also given courses at the University of Cusco, Peru, on academic writing in 2019, and a course of Marie Curie funding at the University of Marburg in 2022. At the University of Turku, I have given several grant writing courses and seminars in 2017-2023.


My research focus, in a broad sense, is in species-environment interactions within a framework covering ecological, ecophysiological and biogeographic approaches. The biogeographic approach is reflected in a broad range of ecosystem that I have worked with. I have carried out work in the Andean high elevation treeline ecosystems, Andean tropical montane cloud forests and lately also on dry savanna environments in Africa.  I have also studied anthropogenic pressures on the ecosystems, developed indices of human impact and compared forest structural characters, such as tree size and seedling abundance, and epiphyte abundance and diversity, between areas of higher and lower human impact.

In my PhD, I specifically focused on climatic and anthropogenic drivers of high-Andean Polylepis forest distribution. I used a variety of methods from field ecology to ecophysiological laboratory measurements and growing experiments, and GIS and remote sensing analyses, aiming at comprehensively answer to the question of the natural and human-based causes limiting the Andean treeline forest distribution. I also used herbarium collections & GBIF database to define species trait - climatic niche relationship.

In my postdoc project, I focused on microclimatic preferences and water retention capacity of the Andean cloud forest epiphytes in Peru. I was specifically looking at what aspects of forest structure and microclimate are related to epiphyte abundance, including vascular and non-vascular epiphytes. I also studied water retention dynamics of epiphytic bryophytes in the community and species level.

Currently, I am studying carbon dynamics (stock and fluxes)  of common Namibian agroforestry trees in dry savanna environment.


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Global fading of the temperature-growth coupling at alpine and polar treelines (2021)

Global Change Biology
Camarero Jesús Julio, Gazol Antonio, Sánchez-Salguero Raúl, Fajardo Alex, McIntire Eliot J. B., Gutiérrez Emilia, Batllori Enric, Boudreau Stéphane, Carrer Marco, Diez Jeff, Dufour-Tremblay Geneviève, Gaire Narayan P., Hofgaard Annika, Jomelli Vincent, Kirdyanov Alexander V., Lévesque Esther, Liang Eryuan, Linares Juan Carlos, Mathisen Ingrid E., Moiseev Pavel A., Sangüesa-Barreda Gabriel, Shrestha Krishna B., Toivonen Johanna M., Tutubalina Olga V., Wilmking Martin
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))

Uraohjaus osana väitöskirjaohjausta (2019)

Johanna M. Toivonen
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))