#Alien invasion california Patch#
But as stewards of not only our own gardens but the ecosystems they comprise, we need to understand how our choices will affect the birds, mammals, insects, and microscopic life forms that evolved in that patch of dirt we call "ours." For example, most people in my area wouldn't dream of planting pampas grass, because we have seen its unsightly incursion into our coastal bluff areas. Those of us who sincerely love our non-native garden plants will be glad to know not all of them are invasive or in any way dangerous. California's "golden hills" are not a part of our natural ecology, and the eradication of the many species of native bunchgrasses in favor of sod-forming European grasses has reduced wildflower populations and diversity throughout the oak grasslands. Over 90 percent of the grass in our state is European weed grass, imported in the manure of livestock. Some areas, such as Hawaii's rain forests and California's oak grasslands, have been almost completely overrun by invasive exotics. This leads to the destruction and extinction of all the plants and animals that once lived in the ecosystem that is being replaced by a monoculture of the successful invader.
#Alien invasion california free#
Some exotics behave well for fifty or a hundred years, before breaking free from constraints and exploding into invasiveness. Natural predators and diseases, as well as competition from other plants, in general give exotics a head start in any system, however closed or balanced it might seem at first glance. While not all non-natives are invasive, most have the potential to become invasive in a way in which native, adapted plants do not.
While much of Devine's call for arms is directed at industry and government, Alien Invasion also contains pleas to gardeners, botanical gardens, nurseries, and growers to consider the consequences of their choices before growing, planting, or distributing a non-native plant.ĭevine considers a plant "non-native" if the ecosystem into which it is introduced did not evolve with that plant. From the kudzu-entangled south to the melaleuca-choked Everglades, from a whitefly-crusted Imperial Valley to a cheatgrass-smothered sagebrush prairie, Devine takes us on a guided tour of an America dangerously overrun by plants and animals that our ecology did not evolve to include. the list of foreign beauties we've fallen for goes on and on.īut not all beautiful plants are benign, as Robert Devine recounts in Alien Invasion. Lantana, hybrid roses, vinca, the graceful fountain of pampas grass, lawn. Gardeners in temperate climates are constantly tempted by beautiful exotics. National Geographic Society, Washington, DC, 1998. donax invasion of riparian ecosystems, which in turn can help prioritize control strategies and revegetation of riparian ecosystems.Main : Holistic Care : Holistic Health for People Index : America's Battle With Non-Native Animals and PlantsĪlien Invasion: America's Battle With Non-Native Animals and Plants These results help elucidate the optimal conditions for A. Arundo donax infestations appear to create an invasive plant-fire regime. donax dominated these burned areas (99% relative cover and a 24% increase in relative cover compared to pre-fire conditions). donax grew 3–4 times faster than native riparian plants. donax began regrowth from rhizomes immediately after being burned in October 2003 along the Santa Clara River whereas native riparian plants remained dormant for several months, and A. donax may take advantage of anthropogenically enriched N (and K) levels in riparian ecosystems. Unlike the native red willow (Salix laevigata Bebb.), A.
donax infestations whereas sites with lower N levels did not. donax infestation throughout several coastal watersheds in Southern California revealed that floodplains with enriched soil NO3-N supported A. Analysis of the influence of nutrient enrichment from residential and agricultural land use types on A. The main hypothesis of this project is that the current abundance of nutrients, water, light, and fire in riparian ecosystems of Mediterranean-type climate promotes A. Urban and agricultural development adjacent to riparian ecosystems may contribute to its invasion success. donax increases the risks of flooding and fire, uses prodigious amounts of water, and reduces habitat value for wildlife. Giant reed, Arundo donax L., is one of the greatest threats to riparian ecosystems of Mediterranean-type climate regions, including California.
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