Genton, Benjamin (2005) Importance of an evolutive approach for the study of blological invasions. The example of ragweed invasion in the Rhone valley. PhD thesis Sciences de l'environnement, ENGREF.
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Alternative Locations: http://www.ese.u-psud.fr/genetique/pdfs/These-BenjaminGENTON.pdf
Abstract
Biological invasions have major ecological and economic consequences. Demographic, ecological and genetic mechanisms involved in bioinvasions are well known, but predicting invasions is still impossible. Approaches exploring the ecological characteristics of invaders or invaded environment do not converge to a unifying pattern. Here, we support an alternate, evolutionary approach that investigates two paradoxes: (1) How can some species succeed in an environment different from the one they are adapted to, sometimes displacing native species that should a priori be more adapted to the local conditions? And (2) how can exotic species adapt so rapidly to new conditions despite founder effects?
North American common ragweed (Asteraceae) is an invasive species in the Rhône valley in France. This weed poses major health problems since its pollen is a strong allergen. To solve the two paradoxes, we conducted different studies comparing French invasive and North American native populations. We found that French populations may be advantaged by an herbivore pressure release. However, we detected no adaptation consecutive to this enemy release. Moreover, we showed that French populations were more diverse than North American ones, using microsatellites markers that were developed for this study. Introductions from multiple source populations seem to have limited founder effects.
Finally, we propose a theoretical evolutionary framework that distinguishes three invasion types: those that require no change in environment or species, those that arise as a consequence of an environmental change and those that result from species adaptation.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| Thesis Supervisor: | Shykoff, Jacqui and Gouyon, Pierre-Henri |
| Date: | May 2005 |
| Board of examiners: | Millier, Claude and Thebaud, Christophe and Vila, Montserrat and David, Patrice |
| Ecole Doctorale: | ED 435 AGRICULTURE, ALIMENTATION, BIOLOGIE, ENVIRONNEMENTS ET SANTE |
| Discipline: | Sciences de l'environnement |
| Collection (Fonds): | ENGREF |
| Institution: | ENGREF |
| Subjects: | 7. Life Sciences and Engineering |
| Uncontrolled Keywords: | Ambroisie, Ambrosia artemisiifolia, Invasion biologique, Bioinvasion, Evolution |
Table of content
Avant-propos
1. Biologie évolutive et écologie des invasions biologiques
A. Comment se répartit la biodiversité ?
A.1. Répartition géographique des espèces
A.2. Facteurs écologiques limitant l'aire de répartition des espèces
A.3. Facteurs historiques limitant l'aire de répartition des espèces
B. Ampleur du phénomène des bioinvasions
B.1. Historique du phénomène des bioinvasions
B.2. Impacts écologiques
B.3. Impacts économiques et sanitaires
B.4. Contrôle des populations indésirables
C. Processus écologiques et évolutifs
C.1. Introduction dans un nouvel environnement
C.2. Etablissement de populations viables
C.3. Prolifération
D. Comprendre les bioinvasions
D.1. Caractéristiques des espèces envahissantes
D.2. Caractéristiques des écosystèmes et communautés envahis
D.3. Paradoxes "évolutifs"
2. L'invasion de l'ambroisie dans la vallée du Rhône
A. Ambrosia artemisiifolia L.
A.1. Description
A.2. Une plante envahissante
A.3. Allergies
B. Relâchement de la pression d'herbivorie
C. Plusieurs sources d'introduction
D. Synthèse
D.1. Ambrosia artemisiifolia et le premier paradoxe évolutif
D.2. Ambrosia artemisiifolia et le deuxième paradoxe évolutif
3. Discussion: développer l'approche évolutive
A. Un cadre théorique "éco-évolutif"
B. Conclusion et perspectives
Bibliographie
Annexe
| ID Code: | 1764 |
|---|---|
| Deposited By: | Benjamin GENTON |
| Deposited On: | 27 June 2006 |
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