The purpose of this thesis is to study the genetic diversity of the clonal plant Cirsium arvense (Asteraceae). C. arvense is one of the most frequent and most successful perennial weeds throughout the temperate zone. The increasing intervention of humans in natural landscapes, which mostly opens the vegetation, multiplies suitable sites for C. arvense. The species is nowadays omnipresent in agricultural or semi-natural landscapes. Because of its economic importance, C. arvense has been intensively studied during the last century. Although a lot of information has been accumulated about the ecology and biology of C. arvense, data about its genetic diversity are missing. Thus, the aim of this thesis was to conduct a mixed approach combining ecology and molecular biology to identify, on a landscape scale, the main factors acting and designing the genetic diversity of C. arvense in natural populations. As a first step, Amplified Fragment Length Polymorphisms (AFLP) were developed to investigate the neutral genotypic and genetic diversity of natural populations of C. arvense. The study focuses on one hand on the impact of the ecological succession, and on the other hand on the occurrence of the phytophagen insect Urophora cardui. Another part of this work concerns the evolution of the reproductive effort of C. arvense and its dispersal capacity along the ecological succession. To summarise, a high genotypic and genetic diversity was found in natural populations of C. arvense. This diversity seems to be maintained through time as populations from early and late successional stages present similar patterns of diversity. The AFLP molecular markers, which are mostly based on nucleic DNA, did not show an isolation by distance. This result suggests that an important nuclear gene flow might occur at our study scale (U. cardui on the genetic diversity of C. arvense, as well the patterns of evolution of the reproductive effort of C. arvense along a successional gradient, can both be understood in a metapopulation context. Therefore, these results suggest a spatio-temporal dynamic of populations of C. arvense, with extinction-recolonisation events.