prof. dr. ir. C. (Chris) Smit

I am currently (co)supervising 7 PhD students and usually between 5-10 MSc students per year. All projects deal with the question how natural communities are shaped by interactions with other species (e.g. plants, herbivores, predators), the abiotic environment. Via these projects I aim to contribute to improved nature conservation and restoration management.

The PhD project of Esther Swankhuisen ( https://www.rug.nl/staff/e.swankhuisen/ ) is on the impacts of (feral) cats at meadow bird populations in the Netherlands. Field work will primarily be carried out in the northern part of the Netherlands (provinces Friesland and Groningen). At the island of Schiermonnikoog (ca. 3-4 field seasons) the effects of (feral) cats at ground breeding bird species – and other prey species – are quantified, and the effects of removal of (feral)cats at these different prey species is assessed. At two meadow bird areas in Groningen and Friesland, data will be collected on habitat use by (feral) cats, and others mammalian predators, and directly linked to survival of (tagged) meadow bird chicks. Furthermore, fecal samples will be collected and metabarcoding analyses are performed to assess the diets of feral cats, and other mammalian predators (lab work). 

The PhD project of Bjorn Mols (https://www.rug.nl/staff/b.mols/research) is about how predators and humans jointly and in isolation create a landscape of fear for ungulates with cascading impacts on the vegetation. Bjorns work entails comparative and experimental field studies in the Bialowieza Primeval Forest in Poland, the Bavarian Forest in Germany, and the Veluwezoom in the Netherlands. The focus of his project is on the ecological impacts of the returning wolf.  

The PhD project of Isabelle Buyens ( https://research.rug.nl/en/persons/isabelle-buyens ) is on plant-plant facilitation, plant trait variation and vegetation
patchiness; more specifically, she addresses the question how plant intra- and inter-specific responses to positive interactions determine patch-dynamics and diversity at landscape scale. As study system, she uses the typical patchy vegetation at the (cattle) grazed salt marshes of Schiermonnikoog, where tall vegetation patches of herbivore defended Juncus maritimus co-occur with palatable Elytriga atherica in a mosaic of short grazed lawns dominated by Festuca rubra and Puccinellia maritima.   

The PhD project of Megan Korte (https://www.rug.nl/staff/m.k.korte/research) deals with the evolutionary consequences of facilitative plant - plant interactions. Megan's model species is the annual arid grass Brachypodium distachyon which she uses for descriptive and experimental field and greenhouse studies (mostly carried out in southern Spain) and modelling work.

Completed projects: 

The PhD project of Nicolas Velasco Saragoni  ( https://research.rug.nl/en/persons/nicol%C3%A1s-velasco-saragoni)   was on disjunct distributions and whether differentiation in ecological traits as morphology and niche relate to variation in the effects produced by populations in different regions. Specifically, Nicolas studied the ecological differentiation (morphological, niche and function) of Acacia caven var. caven, a plant species with a disjunct distribution in the Southern Andes, with populations occurring in both Chile and Argentina on both sides of the mountain range. Nicolas used a combination of descriptive, quasi-experimental, niche modelling, and experimental studies to study this widespread species. Nicolas received his double degree (from University of Chile and University of Groningen) in September 2023.

The PhD project of Lisa Sanchez (https://www.rug.nl/staff/l.sanchez.aguilar/) applied a novel interdisciplinary approach of science and art/design communication to landscape (time) scale ecological processes in rewilding projects and trophic cascades (e.g. Bialowieza Primeval Forest as case study). The aim was to improve our scientific understanding of these processes, and at the same time raise interest and accurately help the broadening up towards public understanding and awareness. Lisa received her PhD thesis in August 2023.

The PhD project of Rik Veldhuis (http://www.rug.nl/staff/e.r.veldhuis/research ) was on the relationship between atmospheric deposition, soil chemistry, mycorrhiza, and the recruitment and vitality of the evergreen shrub juniper (Juniperus communis). Aim of this project was to 1) understand how atmospheric deposition affects the quality, vitality and development of populations of the endangered common juniper, in order to 2) determine which management interventions could best be applied to improve soil chemistry and thus the sustainable recovery of juniper populations.  The project was a collaboration between University of Groningen, B-Ware / University of Nijmegen and Ghent University. Rik succesfully defended his PhD thesis in May 2023.

The PhD project of Annelies van Ginkel (http://www.rug.nl/staff/h.a.l.van.ginkel/research) was a joint project with the Mammal Research Institute in Poland (Dries Kuijper, http://www.zbs.bialowieza.pl/) where we aimed to test the combined impacts of wolves and coarse woody debris on recruitment of various tree species through altered behaviour in red deer (ecology of fear theory). Field work  was predominantly performed in the famous undisturbed primeval Bialowieza forest in Poland.  Annelies got her PhD thesis in February 2020.

The PhD project of Qingqing Chen (http://www.rug.nl/staff/q.chen/research) aimed to focus at the evolutionary consequences of positive plant-plant interactions, and to study the impacts of facilitation on the phenotypic variation and genotypic population structure of ‘protégé’ plants that are being facilitated by ‘nurse’ plants. This was done in a series of lab and field experiments with different environmental stress levels (drought, salinity) for multiple varieties and ecotypes of protégé plants (notably the clonal salt marsh grass Elytrigia atherica).  

The PhD project of Mathias Dillen (http://www.ugent.be/bw/dfwm/en/research/fornalab/staff-fornalab/mathias-dillen) in cooperation with UGhent (Kris Verheyen) focused on the interplay of biodiversity and environmental stress for ecosystem functioning, notably herbivory on tree saplings. This project was embedded within the larger FORBIO experiment set-up in three forest sites across Belgium (http://forbio.biodiversity.be/). Mathias got his PhD degree in September 2017.

The Postdoc project of Georgette Lagendijk (http://www.rug.nl/staff/d.d.g.lagendijk/) aimed at finding an optimal grazing regime for biodiversity conservation, including various trophic levels (plants, invertebrates, rodents, birds). In a large grazing experiment in the salt marshes of Noord Friesland Buitendijks five different grazing regimes were applied: horse and cattle grazing at two stocking densities each (0.5 animals ha-1, 1 animal ha-1), and a rotational grazing regime (one fallow year followed by 1 cattle ha-1). This project focused at the long term effects of the various grazing regimes on the different trophic levels, with particular attention at the effects of the rotational grazing regime.

The PhD project of Mart Verwijmeren (http://www.uu.nl/staff/MVerwijmeren) in collaboration with Utrecht University (Max Rietkerk) dealt with plant-plant interactions along a gradient of environmental stress (drought) in a grazed, arid ecosytem in the southeast of Spain. Mart combined experimental field studies (enclosure studies with goats and rabbits) and observational field studies of plant co-occurence, with modeling studies, with the aim to understand and prevent future land degradation, and catastrophic shifts, in arid ecosytems. Mart got his PhD degree in December 2016.

The PhD project of Ruth Howison (http://www.rug.nl/staff/r.a.howison-fraser/) dealt with the dynamics of vegetation mosaics in grazed ecosystems, and the complex feedback-loops between large herbivores, plant communities and soil macrofauna. Ruth studied the striking similarity between, and processes behind, the vegetation mosaics at the Dutch salt marshes and those in the savannas of South-Africa. Ruth successfully defended in January 2016.

The PhD project of Jasper Ruifrok 'Herbivore-mediated structural diversty of vegetation' comprised of a large multifactorial field experiment in the Oostvaardersplassen with transplanted tree saplings in stepwise exclosures (excluding horses and cattle, or red deer), as well as descriptive and modelling studies on the impact of large herbivores, and their predators, on dynamics and spatial heterogeneity in vegetation structure in this, and other, grazed ecosystems. Jasper successfully defended his thesis in March 2014.