Gene Flow in an Invasive Species of Grass, Brachypodium Sylvaticum

Abstract

Invasive species of plants are responsible for a staggering amount of damage to the landscape and floral and faunal communities. Invasions remain largely ignored until invasive populations have reached critical levels, at which point costly and time-consuming efforts are required for containment or control. Studying the early stages of an invasion can provide insight into the mechanics behind the establishment and spread of invaders, as well as shed more light on the processes of microevolution. Brachypodium sylvaticum is a grass recently invasive to the Willamette Valley, and possesses many traits valuable to a migration and evolutionary study. This study has focused on the aspects of the migration patterns of B.sylvaticum using microsatellite DNA.Microsatellite analysis of two loci determined that the populations studied were experiencing longdistance dispersal, in which large, well-established populations provide seeds to far-away sites; migration patterns of simple diffusion were also seen. In-field observations of this invasive grass suggest that this highly damaging invader enjoys the greatest success in disturbed areas such as logging tracts, riparian areas, and alongside roads. The long-distance migration of this genetic material appears to be propelled, at least in part, by logging trucks and tourists.

The variability of natural populations of Brachypodium pinnatum and B. sylvaticum based on morphological features

“…Despite the low proportion of sexual recruitment, clonal diversity within the population of B. pinnatum was higher than reported for other clonal plant populations (Schläpfer and Fischer 1998). In the USA, where B. sylvaticum is an invasive plant, genetic analyses indicate that both guerrilla dispersal (on vehicles, boots, clothes, and forestry equipment), and simple diffusion are taking place (Dobberstein andCruzan 2004/2005).…”