Ecological and genetic correlates of long-term population trends in the park grass experiment.

The Park Grass Experiment (PGE) is the longest-observed set of experimental plant communities in existence. Although the gross composition of the vegetation was at equilibrium over the 60-yr period from 1920 to 1979, annual records show that individual species exhibited a range of dynamics. We tested two hypotheses to explain why some species initially increased and why subsequently some of these (the outbreak species) decreased again.

Persistence of seeds from crops of conventional and herbicide tolerant oilseed rape (Brassica napus).

A series of rotation experiments at five sites over four years has explored the environmental and agronomic implications of growing herbicide tolerant oilseed rape and sugar beet. This paper reports on the population dynamics of volunteer rape (Brassica napus). The experiments compared four winter oilseed rape (WOSR) cultivars: a conventional cultivar (Apex) and three developmental cultivars either genetically modified (GM) to be tolerant to glyphosate or glufosinate, or conventionally bred to be tolerant to herbicides of the imidazolinone group.