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Analysis of ecological and genetic factors of alien plant invasions along altitudinal gradients in the Swiss Alps and Wallowa Mountains (USA)

English title Analysis of ecological and genetic factors of alien plant invasions along altitudinal gradients in the Swiss Alps and Wallowa Mountains (USA)
Applicant Dietz Hansjörg
Number 104147
Funding scheme Project funding (Div. I-III)
Research institution Institut für Integrative Biologie Departement Umweltwissenschaften ETHZ
Institution of higher education ETH Zurich - ETHZ
Main discipline Botany
Start/End 01.06.2004 - 31.05.2007
Approved amount 248'300.00
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All Disciplines (2)


Keywords (7)

Altitudinal gradient; competition with native plants; genetic variation; growth plasticity; plant invasion; propagule pressure; mountain systems

Lay Summary (English)

Lay summary
Background. Despite the urgent need for a comprehensive understanding of the processes underlying biological invasions our ability to generalize and make predictions about invasions is still weak. Comparative, ecological studies with carefully selected species are required to arrive at an understanding that corresponds with the huge management needs.Comparative studies of plant invasions into mountain systems are particularly promising because they allow detecting the factors limiting the invasion ability of species along pronounced environmental gradients in the introduced area. Mountain systems offer exceptional opportunities to analyze the effects of genetic variation and propagule pressure on the invasion process relative to community invasibility and variation in abiotic stress.

Main Working Hypotheses. 1 - Species reach lower relative altitudes in the introduced area because of (i) lag effects (lower propagule pressure),(ii) the absence of mountain ecotypes or (iii) due to biotic interactions with the native community to which they are not (yet) adapted. 2 - The altitudinal limits of the invasive species due to increasing abiotic stress are influenced by the structure and composition of the native community. 3 - Increased plasticity may be favourable under unpredictable conditions, whereas under more homogeneous stress conditions at higher altitudes a less plastic but well-adapted genotype is more successful.
Specific Aims. The aim of the proposed study is to identify the factors underlying the varying success of invasive exotic forbs in temperate mountain areas in the northern hemisphere. For that we analyze (i) the distribution and structure of plant populations along altitudinal gradients, (ii) responses of individual species to changes in environmental conditions along altitudinal gradients including changes in biotic interactions with the native communities, and (iii) the relative importance of plasticity and genetic adaptation in coping with altered abiotic conditions and biotic interactions at higher altitudes.
Methods and Experimental Design. To investigate these issues we will compare groups of related native and invasive Asteraceae forb species in two mountain systems, the Swiss Alps and the Wallowa Mountains in the US.Our reciprocal approach will include (i) field surveys of invasive populations along altitudinal gradients, (ii) analysis of the patterns of genetic variation within and between populations, (iii) common garden experiments at different altitudes in Switzerland and (iv) transplant experiments in both mountain systems.
Expected Value of the Proposed Project. We expect the proposed project to provide insight in the mechanisms of plant invasions by elucidating the limiting factors of the invasion processes as obtained from mountain systems as model systems for pronounced environmental gradients. The results will also be valuable for an evaluation of the system-specificity of plant invasion patterns and mechanisms, and for the development of policies to control plant invasions, especially to protect fragile mountain ecosystems.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants


Associated projects

Number Title Start Funding scheme
65426 Correlative and experimental analysis of anatomy and ecology of the development of annual rings in the roots of dicotyledonous perennial herbs 01.10.2001 Project funding (Div. I-III)