Friday, June 20, 2008

Why do we restore habitats?

One of the major aspects of the Habitat Authority’s management of open space in the Puente/Whittier Hills is the restoration of degraded habitats. The term "habitat restoration" refers to the process of restoring the functional aspects of a given ecosystem to a semblance of its pre-disturbed state. As a result of more than 100 years of human land use, the majority of the Puente Hills contains disturbed habitats, including those dominated by non-native vegetation. Past and ongoing land uses that have created or contributed to disturbed, altered habitats include livestock grazing, development, oil extraction, the intentional planting of non-native vegetation, and the use of non-native invasive vegetation on properties adjacent to open space where invasive plants spread into natural areas. The Habitat Authority actively restores degraded areas by removing non-native vegetation (such as non-native grasses, mustard, thistle, castor bean, tree tobacco, etc.) and planting native vegetation that would have been present prior to the disturbance.

Approximately 190 acres of Habitat Authority lands have been or are currently being restored in some manner, including 130 acres initiated by the Habitat Authority, and another 60 acres of mitigation conducted on Habitat Authority lands to mitigate for local development projects. Restoration projects include coastal sage scrub and sycamore riparian habitats at the Hacienda Trailhead; riparian restoration in Sycamore Canyon; coastal sage scrub restoration on the former Unocal property (east of Colima Road); coastal sage scrub restoration near the Hellman Trailhead; the restoration of coastal sage scrub at the Arroyo Pescadero Trailhead; and the restoration of oak and walnut woodland, coastal sage scrub, native grassland, and riparian habitats in Powder Canyon.

Though it makes us feel good to be a part of successful restoration projects, that feeling is a byproduct of the broader goal….to improve the overall the health of the ecosystem. Through the restoration of degraded habitats, the Habitat Authority and other participants have created (and continue to create) native habitats offering shelter and food for wildlife that otherwise would not exist in the degraded habitat. For example, the federally listed coastal California gnatcatcher is nesting in coastal sage scrub vegetation at the former Unocal property where the patch of habitat did not exist just two to three years ago. Gnatcatchers have occupied that property in the past, but we have expanded the habitat to allow for the establishment of new territories and the growth of the gnatcatcher population. Besides rare species, we are providing habitat for all sorts of mammals, birds, reptiles, amphibians, and invertebrates.

Earlier this week I visited our former Diaz property on the far eastern edge of the preserve near Harbor Boulevard. Five years ago this property contained a house and other structures, an avocado orchard, and countless more non-native vegetation. Since then we have restored nearly 25 acres to coastal sage scrub and oak/walnut woodland. During my visit the other day, I came across a family of mule deer that are regular residents of the property. As I walked through the site, I was treated with the appearance of two fawns that calmly walked out from the shelter of a grove of walnuts (see photo above). It is rewarding to know that the habitat was restored for them.

1 comment:

Ouija said...

I know that the habitat authority removes non native foliage but to cut down the naturalized Eucalyptus trees that provided shade and homes for wildlife in Arroyo Pescadero is ridiculous.. the hillside looks terrible and the owls who normally nest in the trees are gone! These groves have been a wind block and provided shelter and beauty for many many years, they were not taking over the native plants. Booo!