Drawing on a long history of studying natural ecosystems, most of us rely on the species concept to conceptualize and quantify the diversity and composition of urban ecosystems. Many urban plants, however, are cultigens that are the product of artificial selection and don’t always easily fit traditional ecological models and taxonomies. Fortunately, the process of cultivation and the history and practice of horticulture are closely tied to the very human-ecosystem interactions that are central to urban ecology. By studying these processes, we may be able to significantly advance our understanding of urban ecosystem structure and function. The history of selecting for specific plant traits that produce food, aesthetic qualities, and other human benefits goes back centuries, and has been studied in agroecology, cultivated plant taxonomy, environmental history, cultural geography, and other disciplines. Given the dominance of cultigens in many urban ecosystems, can we incorporate and adapt lessons learned from these studies into urban ecological methods and theory?
Results/Conclusions
There are numerous ecological dimensions of the history and types of plant cultivation found in cities. Here I’ll focus on three: 1) Environmental and geographical histories of plant imports and the horticultural trade have been very informative for understanding invasion ecology, and may be equally informative in cultivated ecology. 2) An understanding of the attributes of plants that have attracted human attention, which is emerging from studies of human-plant geography, may provide new insights into why certain plant traits and taxa are prevalent in cultivated urban gardens. Selection for large and complex flowers, for example, is a dominant feature of urban horticulture that might be better incorporated into our understanding of urban ecological processes. Finally, from a classic ecological and evolutionary perspective, horticultural plants have greatly benefited from cultivation, and their reproductive success can be attributed to their interrelationships with humans. Therefore, agroecologists have described the process of crop and domesticated animal cultivation as a mutualism, which is likely to be equally applicable to the cultivation of horticultural plants. These lenses on human-plant relationships are more expansive than previous ecosystem services concepts, in that they’re two-directional and highlight the complex and reciprocal effects of cultivation on both humans and non-humans.