PNAS: Painting with Invasive Pigments

 Artist Ellie Irons creates watercolor paints by extracting pigments from weedy urban plants. In Dot Cluster: Wild Plants Common in New York City, 2016, she uses those paints to describe the community of plants growing across about 25 vacant lots in Brooklyn. Image courtesy of Ellie Irons.

Artist Ellie Irons creates watercolor paints by extracting pigments from weedy urban plants. In Dot Cluster: Wild Plants Common in New York City, 2016, she uses those paints to describe the community of plants growing across about 25 vacant lots in Brooklyn. Image courtesy of Ellie Irons.

USL Director Timon McPhearson was quoted in a recent PNAS article on Brooklyn-based artist Ellie Irons, who uses pigments derived from invasive species, or what she calls "spontaneous urban plants," to create vibrant watercolor diagrams showing the spread of plants.  

"So, do invasive plants in these more urban communities provide ecosystems services the same as or better than native plants would? “They might,” says urban ecologist Timon McPhearson, director of the Urban Systems Lab at The New School, and lead author of a study analyzing the vegetative land cover of about 1,500 New York City vacant lots. He found that urban plants are providing key services, such as stormwater mitigation, air pollution removal, and carbon sequestration (3). “One reasonable hypothesis is that if invasive species can grow faster, reproduce faster, spread faster, they might be critical for providing climate adaptation related to ecosystem services that we care about like stormwater absorption and cooling the city.”

McPhearson would like to see more research into how the traits of specific species—whether native or not—affect ecosystem services in cities. Few researchers have studied, for example, the effect of nonnative species on carbon dioxide sequestration, air quality, and nutrient cycling in cities, as noted in a recent review (4)."