Rattlesnakes, lizards, and horned toads invade 

 from the desert but are not particularly characteristic 

 of the woodland itself. Invertebrate populations are 

 relatively low, and consist principally of spiders, ants, 

 termites, jumping plant-lice, and a sprinkling of ich- 

 neumonids, flies, leafhoppers, beetles, and banded- 

 wing locusts (Rasmussen 1941). 



CHAPARRAL BIOME 



Chaparral, in the strict sense, consists of 

 xeric broad-leaved evergreen bushes, shrubs, or 

 dwarf trees, usually not more than 2.5 m (8 ft) high, 

 and occurring in more or less continuous stands. Be- 

 neath the bushes and shrubs there may be abundant 

 ground litter. Chaparral is less dense where there are 

 rock outcroppings and grass. Most species readily 

 produce sprouts after their tops are destroyed by fire, 

 provided fire does not occur too frequently ; germina- 

 tion of some seeds is hastened by the heat of the fire. 

 Chaparral tends to spread as a serai stage into areas 

 of montane forest and woodland when the latter is 

 destroyed by fire. Although chaparral is doubtless 

 serai over nuich of its range, it appears to be climax 

 over fairly large areas in southern California and 

 northern Baja California, and a narrow belt on the 



slopes of the Sierra Nevada and southern Rockies. 

 Broad-leaved evergreen chaparral also occurs, with 

 woodland, around the Mediterranean and elsewhere 

 on other continents. 



PLANT ASSOCIATIONS IN 

 NORTH AMERICA 



Coastal chaparral occurs from southern 

 Oregon to northern Baja California and eastward 

 into Nevada and Arizona (Weaver and Clements 

 1938). This region is one of winter rains, and con- 

 sequently the vegetation consists chiefly of ever- 

 green bushes and shrubs with leaves that are glu- 

 tinous, odorous, or hairy. Coastal chaparral occurs 

 in more massive stands than does petran bush. 



Petran bush occurs as a lower zone on the moun- 

 tains from South Dakota to Texas and westward into 

 Nevada and Arizona. This association has been 

 called petran chaparral, but the shrubs and bushes 

 are mostly deciduous. 



Both associations are derived from the Madro- 

 tertiary flora (Davis 1951) and have a phylogenetic 

 history similar to the oak woodland and piiion- 

 juniper woodland respectively, with which they are 

 closely associated. 



CHAPARRAL BIOCIATION 



There are no mammals peculiar to the 

 chaparral in North America, although in Utah the 

 bobcat, rock squirrel, and cliff chipmunk reach rela- 

 tively large populations in the petran bush (Hay- 

 ward 1948). In California, the brush rabbit and the 

 dusky-footed wood rat are numerous in heavy brush, 

 along with other mammals also found in woodland 

 (Vaughan 1954). There may be 6 to 12 occupied 

 houses of the white-throated wood rat per hectare 

 (2-5/acre) in southern Arizona (Hanson 1957). 

 The mule deer becomes common (about 10/sq km or 

 25/sq mi) during the winter when it migrates down 

 from the higher elevations in the mountains. The 

 chaparral fauna, like that of the woodland, is largely 

 ecotonal between montane forest and grassland or 

 desert scrub. 



The coastal chaparral is extensive enough, how- 

 ever, so that these birds show preference for it 

 (Miller 1951) : 



Mountain quail 

 California quail 

 Anna's hummingbird 

 Allen's hummingbird 

 Wrentit 

 Bewick's wren 

 California thrasher 



*Orange-crowned warbler 

 *MacGillivray's warbler 



* Lazuli bunting 



* Rufous-sided towhee 

 Brown towhee 

 Rufous-crowned sparrow 

 Black-chinned sparrow 



312 Geographic distribution of communities 



