Nonnative Plants in California

* Re “Invasion of the Green Aliens,” Nov. 2: I think we are in serious danger of losing much of Southern California’s wildlife heritage due to the replacement of native plant species with alien plants.

In 1983, my husband and I bought my parents’ house, where I had lived previously, some two decades before. One of the attractions for me was the sagebrush-filled canyon that extends down some 200 feet at the back of our lot. I remembered the wild birds and animals that I enjoyed watching as a kid. But things had changed. The roadrunners were gone. The desert cottontails and jack rabbits were gone. Many species still present were much less numerous.

Neighboring areas had built up, with developers having cleared not only areas to be built on but large adjacent areas of native plants. Some residents in our neighborhood, including my parents, had chosen to clear canyon walls and plant nonnative species. This opened the door to fast-growing nonnative weeds like fennel. My husband and I, after a half-century of seeing our native plants and animals disappear, decided to remove fruit trees and weeds from the canyon wall behind our lot, and to try to get the natives to return from nearby areas. It was too late for the roadrunners and cottontails, but we have hopes for the continued survival of the cactus wren and the wintering fox sparrow that are currently fellow residents.

MARGARET HOGGAN

Rancho Palos Verdes

* I have observed that the nonnative plants in the Santa Monica Mountains thrive only on disturbed land; that is, land which has been graded, grazed, eroded, cleared or trampled. The nonnatives appear to pose no threat to our native flora on land undisturbed for decades. Indeed, just 100 yards from Mulholland Drive in Tarzana the only nonnatives I find are on the trail. Even sites formerly occupied decades ago in Topanga State Park have been completely reclaimed by our native chaparral.

The success of the “green aliens” is a symptom and not the cause of our native flora’s loss of diversity. The cause is the loss and abuse of our remaining open spaces.

CHUCK MILBOURNE

Woodland Hills