Matthies
Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Evolutionsbiologie und Umweltwissenschaften, Institut für » Ecology & Environment » PD Dr. Diethart Matthies (ausgetreten) » Matthies
Completed research project
| Title / Titel | Conservation biology of declining grassland species: experimental analysis of population processes | ||||
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| Abstract (PDF, 14 KB) | |||||
| Summary / Zusammenfassung | In the last decades many plant species have experienced a dramatic decline in the number of popu-lations and the remaining populations are frequently small and isolated from each other. Environmental stochasticity and genetic erosion pose considerable threats to small and isolated plant populations. Successful management of declining species to conserve plant biodiversity requires an understanding of both demographic and genetic processes at the population level and of their importance for local extinctions. The first aim of our project is to analyze the mechanisms driving the population dynamics of plant species in decline. We will investigate the relationship between environmental factors, variability of demographic parameters, population size, and risk of extinction in several short-lived grassland species. All demographic data will be integrated into stochastic matrix population models to iden-tify critical transitions in the life cycle and estimate critical population sizes. Part of the project will be a continuation of demographic studies with Gentianella germanica. This offers the chance to obtain long-term estimates of the temporal and spatial variability of demo-graphic transition rates. They will be integrated into models to study minimum data requirements for reliable predictions of population trends and extinction risks in rare species. Results of the first phase of the project indicate that reproduction is the first component of a plant's life cycle that be-comes negatively affected by reduced population size. We will investigate the relationship between population size and reproduction in a large number of declining plant species to determine critical population sizes for reproductive success. The results will be compared with results from the general demographic studies. The second aim of the project is to assess the importance of genetic variability for the population dynamics of declining species. Two different approaches will be used. First, we will study the effect of increased gene flow on the growth and survival of plants in small populations. This study has important implications for habitat management. Second, we will experimentally investigate the im-portance of initial genetic diversity for the success of founder populations. |
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| Publications / Publikationen | Fischer, M., Matthies, D. (1998). RAPD variation in relation to population size and plant performance in the rare Gentianella germanica. American Journal of Botany 85:811-819.Matthies, D. (1998). Creating rare plant populations. Review of "Restoring diversity: strategies for reintroduction of endangered plants" by Falk, D.A., Millar, C.I. and M. Olwell (eds.). Conservation Biology 12: 254 - 255.Kéry, M., Matthies, D., Spillmann, H.H. (2000) Reduced fecundity and offspring performance in small populations of the declining grassland plants Primula veris and Gentiana lutea. Journal of Ecology 88: 17-30. | ||||
| Keywords / Suchbegriffe | Declining species, gene flow, population dynamics, population viability analysis, species conservation, inbreeding, reproduction | ||||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
SNF (Personen- und Projektförderung) |
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| Duration of Project / Projektdauer | Jul 1996 to Dec 2005 |