Urban landscape design can be repetitious to extravagant, lush to ridiculously sterile. Landscape design is a contrived artistic system of imposed order. It can complement and encourage the ecology of an area or fight against it. Often designs are not integrated with the natural environment.
An ecological approach to landscaping allows for the interaction of multiple organisms. Plants need insects for pollination; birds and animals for seed dissemination. Certain animals disturb the soil for seed germination. Animals and birds need vegetation for food and shelter, to reproduce young and for thermal cover during the winter.
Within every healthy landscape, there are interactions among the organisms, whether mammals, birds, insects, plants or the organisms in the soil. In a well-functioning landscape, beneficial predator mites keep detrimental plant-feeding mites under control without chemicals. Insects eat other insects. Smaller birds also eat insects. Hawks, owls and other raptors reduce vole, mice and ground squirrel populations. Certain plants host butterflies and other pollinators. Moles and earthworms aerate and loosen soils while consuming pest organisms. However, the spread of traditional urban landscaping can reduce predator and bird habitat and threaten communities of native plants and insects.
Why should we care? How valuable are songbirds? What purpose do moths serve? Why care about earthworms, nematodes, fungi, bacteria or mycorrhizae in a soil? Is there a loss to the human community, if a species of bunchgrass or some other plant goes extinct? We do know that living systems and the individual organisms, including humans, making up those systems are interrelated. We don’t know what the long-term effects are if we change those interrelationships, eliminating or reducing one or more of the players.
Healthy ecosystems serve many functional purposes on which humans depend. They affect the weather. They maintain the quality of the atmosphere. Fresh water is supplied through the hydrologic cycle. Soils are generated and maintained through the breakdown processes of the decomposing organisms. Wastes are recycled. Food is supplied. A genetic library is maintained.
In nature, there are many impartial disturbances: insect infestations, floods, fires, avalanches, droughts and winds that do not yield to our efforts to control them. To live more safely with these challenges, we need to plan for them in our landscape designs. Landscapes must be integrated for fire and flood safety, erosion control, sustained environmental health, water efficiency, function and, of course, beauty. Some traditional landscape design concepts may need to be abandoned or changed dramatically.
JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension. She can be reached at firstname.lastname@example.org.