My main long-standing interest has been the ecology of plant populations and how they are influenced by phytophagous insects and plant pathogens. This led to the study of phenotypic plasticity and genetic differentiation of various species in different habitat types, effects of disease epidemics and insect herbivory on plant competition, demographic and genetic aspects of within- and among-population variation in space and time, and trans-continental comparisons.
The study of ecological interactions both at the individual plant and at the population level between Senecio vulgaris and the rust fungus Puccinia lagenophorae has been the major focus of my research during the past 12 years.
Since 2000, I have become interested in various aspects of conservation and restoration ecology, especially on mechanisms of local adaptation and biodiversity management, both in agricultural and alpine habitats.
Since 2004 I have come back to topics of my PhD: Plant invasions and biological control; my theoretical and experimental studies predominantly deal with the prediction of evolutionary changes in invasive, exotic plants and their consequences for plant-herbivore interactions, such as for biological control measures.
In 2013, our project proposal on “Sustainable management of Ambrosia artemisiifolia in Europe (SMARTER) became funded as COST-FA1203 and presently, more than 180 researchers with expertise in weed science, biological control, health care, aerobiology, economy and atmospheric and agricultural modelling. from over 33 countries, are participating in this unique European research initiative.
SMARTER website: this is the website of our COST-SMARTER Action http://www.ragweed.eu/
- This is the Leaflet we made to brifely describe our Action
- This is the Poster that shows the problems caused by Ragweed and our suggested solutions
- This is the Video about SMARTER on Youtube (2013/11/29)
- This is the iphone App ‘THE SMARTER AMBROSIA REPORTER’
- This is the Video of " Common ragweed - seeds, pollen and allergy"
CENTAUREA STOEBE SPOTTED KNAPWEED, AS A RESEARCH MODEL
Using the model species Centaurea stoebe, introduced from Central Europe into North America during the late 19th century, and where it covers now an area larger than Switzerland (Müller-Schärer et al. 2004), we explore the inter-relationship between the life-cycle habit, ploidy level and breeding system, and their associations with the invasion success.
PROJECTS AND FUNDING
Swiss NCCR "Plant Survival", a research programme of the Swiss National Science Foundation TG3 and WP3 : Evolution and spread of potential invasive plants (2005-2013) · More information
Swiss National Science Foundation: Polyploidy, herbivory and plant invasions (2009-2012)
COLLABORATORS AT UNIVERSITY OF FRIBOURG
Antoine Guisan · University of Lausanne · Co-PI
BIOLOGICAL CONTROL OF RUMEX SPP IN EUROPE
Rumex obtusifolius is widespread throughout Europe and recognized as the economically most important native weed in grassland ecosystems causing yield losses of up to 30%. It can spread rapidly due to its high seed production and ability for clonal growth, and is unpalatable to several livestock. Chemical and mechanical control measures are widely applied, but their efficiency is unsatisfactory and highly costly. The same holds for previous biological control attempts using the leaf feeding chrysomelid beetle Gastrophysa viridula and the leaf rust pathogen Ramularia rubella.
In contrast, a root-feeding Sesiid moth has been recently introduced from Europe into Australia, mainly against Rumex pulcher, which resulted in sustainable control. Following on this success, a research consortium led by CABI Europe-Switzerland Center, and including an industrial partner, was formed in Switzerland to explore the potential of the native root borer Pyropteron chrysidiforme (Lep.: Sesiidae) as an inundative biocontrol agent against Rumex obtusifolius.
The work at the University of Fribourg mainly focuses on biosafety studies and potential non-target effects. We presently perform a series of oviposition and larval transfer tests on more than 20 test plant species including closely related crop and native plants to assess its host specificity. Preliminary results indicate significant oviposition preference for the target weed.
Further biosafety studies include the development of procedures to increase early larval survival on the target plant, an extension of host specificity tests also to field conditions, and environmental risk assessments such as the response of potential predators to an increased occurrence of this Sesiid.
DEVELOPING A BIOLOGICAL PLANT PROTECTION PRODUCT AGAINST DOCK PLANTS (RUMEX SPP).
CTI project 2010-2013 (780,00 CHF)
|The most important grassland weeds in Europe|
COLLABORATORS AT THE UNIVERSITY OF FRIBOURG
- Tiziana Pedrotta (MSc student)
- Vanessa Schneider (MSc student)
- Heinz Müller-Schärer (co-PI)
- CABI Europe-Switzerland Centre, Delémont (PI)
- Agroscope Reckenholz-Tänikon ART, Reckenholz (co-PI)
- Andermatt Biocontrol AG, Grossdietwil (co-PI)
- Swiss Confederation's Commission for Technology and Innovation (CTI)
- National Centre of Competence in Research (NCCR) Plant Survival, a research programme of the Swiss National Science Foundation
- University of Fribourg
A small leaflet is available in English, German, French and Italian
Checklist of alien invasive plant species of Georgia
The Flora of Georgia is amongst the richest in Europe and comprises approximately 4100 species of higher plants. Preliminary observations indicate that this extraordinary wealth of plant diversity is now greatly threatened by the spread of alien plants, which has especially increased due to changes in land use, cross-country pipeline construction, and habitat destruction.
|A joint research project between Georgia and Switzerland aimed to survey the alien plants (AP) of Georgia in expected sensitive habitats across all accessible historical-geographical regions across Georgia. We restricted our survey to seed plants (Gymnospermae and Angiospermae) and naturalized species, thus excluding alien crop or ornamental plants that have not escaped from cultivation.|
|In our collaborative studies, we give special emphasis to some of the most invasive plants, especially Phytolacca americana(Pokeweed), Ambrosia artemisiifolia (Common Ragweed) and Robinia pseudoacacia (Black Locust). These studies allowed us to roughly estimate the abundance, distribution and invasive potential of AP in Georgia, to identify habitats most susceptible to invasions, and to assess the invasion impact of selected AP. Such basic knowledge is also a pre-requisite for potential subsequent biological control measures.|
COLLABORATORS AT TH UNIVERSITY OF FRIBOURG
COLLABORATORS IN GEORGIA
|Click on the title page to get the pdf of this Brochure: KikodzeD, Memiadze N, Kharazishvili D, Manvelidze Z and Mueller-Schaerer H. 2010. The alien flora of Georgia. Joint SNSF SCOPES and FOEN publication.|
PRESENT AND FUTURE STUDIES
Present studies (2008-2012) concentrate on management measures for Ambrosia artemisiifolia,especially in pipeline corridors across the country, with partial funding by British Petroleum.
SURVEY AND CONTROL OPTIONS FOR INVASIVE AMBROSIA ARTEMISIIFOLIA RECORDED FROM PIPELINE RIGHT-OF-WAYS AND ADJACENT CROPS IN GEORGIA (2009-2011)
Below: predicted potential distribution of Ambrosia artemisiifolia in Georgia
A further project deals with present and expected future biodiversity impact of invasive plants in Georgia (cf MSc thesis by Daniela Thalmann).
We are able to do some routine molecular techniques such as DNA extraction, PCR, gel and polyacryamide electrophoresis, AFLPs and SSRs. The lab is equipped with an ABI 3130 Genetic analyser.
Absolute and relative genome size measurements are performed using CyFlow cytometer (Partec) and a propidium iodide staining procedure. This technique allows us to distinguish small genome size differences between closely related taxa, as well as to estimate relative DNA-ploidy levels from different plant tissues, including seeds (seed progeny analysis).
It is equipped with one light microscope (Leica DMLB) and two stereomicroscopes Leica MZ6 and MZ8. We use them for routine observations of karyological or pollen samples, or other plant microstructure (e.g. trichomes). More sophisticated techniques (e.g. fluorescence microscopy) can be done at the Plant Biology. Further, we have constructed facilities to measure gas exchange both at the level of individual leaves and the whole plant.
The capacity of the greenhouse is 100 m2. Aeration, heating, as well shading is automatic (depending on our demands). We also have space outside in our garden and have the possibility of cultivating plants in other nearby fields and greenhouses.
We have several walk-in climate chambers to grow plants and raise insects, and have privileged access to the insect quarantine facilities at the CABI Europe-Switzerland Institute in Delémont.