Native Species

Native species are the species of plants, animals, and insects that have inhabited a given area or region prior to human disturbance. These original inhabitants are adapted to the specific environmental conditions of their area. They make up the various interdependent parts of the food chain and are an integral part of the regional web of life. Most species have a resident natural predator within the food web that keeps populations of native species in check.

Native species have received a lot of attention in the last decade in two main interest areas: (1) landscaping in an increasingly energy- and water-restricted world; and (2) nonnative invasions. Conventional landscaping traditionally uses exotic plants to enhance an area with colors and shapes from a standard toolkit of vegetative materials. The act of conventional landscaping produces an artificial ecosystem to the extent that earth is often scraped clean and a full array of plant materials is placed to live upon it. Although such plantings are culturally accepted and even expected, they are energy- and water-intensive. As a result, in the last decade there has been more and more interest in native species plantings, since these plants are already adapted to the nutrient and water regimes of the area and therefore require little, if any, added inputs of energy (e.g., petroleum-based fertilizer and insecticides) or water. Additionally, native plantings tend [Page 1214]to attract the native fauna and insects, benefitting pollination and the local ecosystem overall.

One area of particular interest within the native landscaping movement is grass-free lawns. Conventional lawns require large amounts of water and fertilizers, insecticides and pesticides to stay green. In many drought-stricken areas of the United States, homeowners are replacing their green lawns with hardy native groundcovers that require no extra irrigation.

Nonnative invasions are another reason why native species have received a lot of recent attention. The introduction of nonnative species is nothing new—ever since humans have colonized new areas, they have consciously or unconsciously brought nonnative species with them. Ecological imbalance occurs when nonnative species take over the niches of native species because of a lack of natural predators in that ecosystem. They simply out-compete native plants and animals for space, food, or water. In some cases, nonnative species make it difficult or impossible for native species to survive by fundamentally altering natural disturbance regimes and other ecological processes.

Nonnative species are introduced via deliberate and nondeliberate acts of human disturbance. Several prominent historical examples of the unintended introduction of nonnative species include the Japanese beetle, Japanese honeysuckle, and rats brought from the Old World to the New World in ships' hulls. Humans have also intentionally introduced invasive species in attempts to deal with ecological issues, but with negative repercussions for the rest of the ecosystem, such as in the introduction of the zebra mussel to the Great Lakes and the cane toad to Australia. Nonnative species continue to spread largely due to lack of public education. Nurseries continue to sell invasive plants as landscape materials and exotic plants and animals remain popular. Nonnative species endanger the earth's already threatened biodiversity. In the process of invasion, nonnatives can push rare species to the edge of extinction.

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