COLONIZATION OF EXPERIMENTAL PATCHES IN A MOWN GRASSLAND

Colonization of experimentally created patches was studied on an amenity grassland in Wales, where the most abundant plant species was Holcus lanatus (Poaceae). The patches were of three different sizes (200 cm2, 40 cm2 and 15.4 cm2) and two different types: gaps and planted stands of H. lanatus. Most patches were colonized rapidly and were fully covered after two months. Patch size, of both gaps or Holcus stands, influenced colonization by many species. As expected most species entered into the centers of small patches more rapidly than they entered into the centers of large patches. A few stolon-forming species and H. lanatus entered large patches equally or more rapidly than smaller patches. Patch type (gap or Holcus stand) influenced colonization by only three species. In spite of its dominance in the vegetation, there is little evidence from this study that H. lanatus had much negative effect on the growth of other species in this mown grassland.