Genetic analysis reveals human-mediated long-distance dispersal among war cemeteries in Trifolium micranthum Bram D’hondt • Peter Breyne • Wouter Van Landuyt • Maurice Hoffmann Received: 2 March 2012 / Accepted: 14 June 2012 / Published online: 30 June 2012 Ó Springer Science+Business Media B.V. 2012 Abstract Many grassland plant species have limited capacity to disperse their seeds beyond local bound- aries by natural means. Meanwhile, various forms of human transportation are observed to provide long- distance dispersal. However, the contribution of human-mediated dispersal to the spatial dynamics of established (meta)populations on the regional scale has only scarcely been addressed. Trifolium micranthum is a very small legume that is rare in western Belgium. It is found (i) inland, as a lawn weed on war cemeteries that are managed by the Commonwealth War Graves Commission, and (ii) in coastal grasslands that are managed for conservation. These stations lie over 30 km apart, though interestingly, a number of satellite war cemeteries are found within the vicinity of the coastal reserves, and these also harbor T. micranthum. We have sampled plants from these populations to study their affinities through genetic analysis (AFLP). Results indicated that the coastal cemetery populations were closely related to the inland cemeteries and not to the coastal reserves. This most likely is the result of exchange of seeds with composted lawn material among regions, whereas mowing machinery and livestock may effectuate frequent dispersal within regions. Assignment tests nonetheless indicated lim- ited genetic admixture to have taken place at the coastal cemeteries. Thus, human management is responsible for the realization of gene flow among these remote gene pools. Human-mediated long-distance dispersal is likely to play a role in the local or regional dynamics of many other native plants, including more common and well-dispersing species. Keywords Anthropochory Á Regional ensemble Á Spatial genetic structure Á Gene flow Á Landscape genetics Á Amplified fragment length polymorphism Introduction Seed dispersal is a key component in the spatiotem- poral dynamics of a plant species’ distribution (Cou- sens et al. 2008). Although examples abound of plant attributes suited to promote dispersal over consider- able distances, many herbaceous and graminoid species appear to lack any of such traits (van der Pijl 1969; Hughes et al. 1994). In fact, dry, small, and overall inconspicuous (i.e., ‘‘unassisted’’) seeds con- stitute the dominant seed syndrome in open Electronic supplementary material The online version of this article (doi:10.1007/s11258-012-0082-9) contains supplementary material, which is available to authorized users. B. D’hondt (&) Á M. Hoffmann Terrestrial Ecology Unit, Biology Department, Ghent University, 9000 Ghent, Belgium e-mail: b.dhondt@ugent.be P. Breyne Á W. Van Landuyt Á M. Hoffmann Research Institute for Nature and Forest, 1070 Brussels, Belgium 123 Plant Ecol (2012) 213:1241–1250 DOI 10.1007/s11258-012-0082-9