Abstract
Agroecosystems are, at their core, composed of interacting species. Farmers take advantage of specific technological packages to manage their crops and animals (i.e., the planned biodiversity). These practices and the ecological context where they occur, in turn, result in the presence of a variety of genes, species, ecological networks, or functional traits not intentionally introduced and managed by the farmer but naturally occurring within crop fields, along field margins, and across agricultural landscapes (i.e., the associated biodiversity). As members of the associated biodiversity, weeds are an unavoidable and ever-present component of agroecosystems that, through competition and multitrophic interactions, impact the functioning and dynamics of agroecosystems. In this chapter, we (1) review the ecological impact of edible weeds, also referred to as edible noncrop plants, on the other components of associated biodiversity; (2) present case studies from temperate annual row cropping systems, the agroecosystem we have been studying for more than 20 years, on the ecological role of edible noncrop plants; and (3) propose avenues for future research. We are hopeful that an increased appreciation of the functional importance of edible noncrop plants will promote awareness of the role that the associated biodiversity plays in fostering sustainable agriculture. This awareness, in turn, will help increase the implementation of sustainable agricultural management systems that will favor multiple ecosystem services while maintaining food, fiber, and bioenergy production.