Evolutionary Ecology Models of Weed Life History

Weeds and invasive plants perform the colonization niche by seizing locally available opportunity spacetime created by human activity. The urge to understand and predict weed life history behavior provides a strong scientific and practical motivation to develop models. Most current weed models are quantitative and demographic. This chapter is a critical review of the limitations of demographic models and well as the opportunities provided by evolutionary models. Several fundamental flaws are associated with the way the local population is represented in demographic models. The first artifact is the confounding effects of plant, as opposed to animal, population structure. The second derives from how unique individual phenotypes in the local population are represented. The third arises from population membership changes with evolutionary time that compromise assumptions of deme covariance structure. As an alternative to demographic models, an evolutionary model of weed population dynamics is based on the actions of functional traits guided weedy plant life history behavior in a deme as a consequence of natural selection and reproductive success among excess variable phenotypes in response to the structure, quality and timing of locally available opportunity spacetime. The thesis of this chapter is that understanding population dynamics in agroecosystems requires a qualitative evolutionary representation of local