Effects of chaparral conversion on small vertebrates in Southern California

Lizard and small mammal faunas were sampled on eight sites of chaparral and artificial chaparral-grass conversions in southern California. The abundance and diversity of these faunas were characteristically greater in chaparral than in areas of grass. The deer mouse (Peromyscus maniculatus) was the only animal studied that was abundant on both chaparral and grass sites. In early stages of chaparral-grass conversion, mechanical brush clearing (Bulldozing, discing)_appeared to cause greater initial reductions in small vertebrate populations than did the use of selective herbicides (primarily 2,4-D). Both lizards and small mammals were virtually absent from grass that was heavily grazed. Lizards reached peak abundance in recently burned (relatively open) chaparral.