The Conservancy’s first restoration and enhancement project has been challenged by a proliferation of exotic weeds. Working with consultants and specialists, Conservancy staff has attempted to control the weeds so that the many native species of grasses, shrubs and trees will be able to effectively compete. One of the last remaining non-chemical control tools available to the Conservancy is sheep, which have recently been introduced to the site.
Some 400 ewes were introduced to the BKS site in early July 2002. The introduction of the sheep followed efforts cattle grazing and selected mechanized cutting to control weeds, particularly star thistle and bull thistle. Weed specialists have labeled the site, prior to construction, as having one of the worst exotic weed infestations in the Natomas Basin. The Conservancy is committed to exploiting all non-herbicide means of controlling exotic weeds.
The native shrubs that have recently been planted on the site include:
California Blackberry, Rubus vitifolius
California Wild Grape, Vitis californica
California Wild Rose, Rosa californica
Coyote Brush, Baccharis pilularis
Mule Fat, Baccharis vimimea
Among the many native grasses that were planted on the preserve were Blue Wild Rye, California Barley, Idaho Fescue, Native California Brome, Pine Bluegrass and Purple Needlegrass. The native grass species are most at risk of being overwhelmed by the extoic weeds on the site.
Conservancy staff and consultants are so far very pleased at the progress the sheep have made on the property. Continued active monitoring will determine if grazing sheep will have a longer-term beneficial effect on this preserve.