8 THE BHOAD-SCLEROPHYLL VEGETATION OF CALIFORNIA. 



province of this work. Four papers dealing with difficult genera 

 should be mentioned: Abrams on Uva-Ursi [Arctostaphylos] (2), 

 Trelease and Brandegee on Ceanothus (89, 10), and Miss Eastwood 

 on Garry a (28). 



(b) Papers by foresters may be grouped in two classes: (1) those 

 deaUng particularly with chaparral; (2) descriptions of various 

 forest reserves in which chaparral occurs. One of the former, 

 by Plummer (74), purports to be a rather full discussion of the subject 

 from both the purely scientific and the economic standpoints. 

 It is totally inadequate. All the other papers by foresters deal 

 with conditions in more or less restricted localities. Those by Boerker 

 (9), Foster (30), Haefner (37), and Sterling (85) treat of northern 

 California, where the chaparral is mainly of the temporary kind. 

 Naturally the successional relations with the forest trees and the 

 effects of fire upon these are treated with considerable detail. Sub- 

 division of the general type into communities and subcommunities 

 is attempted to some extent, and also the correlation of these in a 

 very general way with habitat factors, especially slope exposure. 

 The work has been almost wholly observational, with no exact 

 habitat measurements and few statistical studies of the vegetation. 

 Miller (64), studying the chaparral of northern California as a 

 watershed cover, gives some data bearing upon successional relations. 

 In the works of more general scope by Barber (6), Leiberg (50-56), 

 and Sudworth (86) there is considerable material of value relating 

 to the extent, composition, zonation, and successional relations 

 of the chaparral in various parts of the State. E. N. Munns has put 

 forth three papers (66-68), in which some instrumental habitat 

 data are presented. He has also much valuable material, as yet 

 unpublished, to which I have had access through his kindness. 



(c) Four papers dealing with the phytogeography of southern 

 California must be mentioned. McKenny (60) recognizes in Orange 

 County seven formations, two of which (the mountain and the 

 foothill formations) are mainly chaparral of various types, which 

 are not very clearly distinguished. Hall, in his account of the San 

 Jacinto Mountains (38), relates the vegetation to the well-known 

 temperature zones of Merriam, and distinguishes two altitudinal 

 belts of chaparral, the lower dominated by Adenostoma, the upper 

 by Castanopsis and other genera. He also summarizes the obvious 

 ecological characteristics of the average chaparral shrub, noting 

 reduction of leaf-surface, vertical position, thickness and leathery 

 quality, frequency of woolly pubescence (with which I would dis- 

 agree), and depth of penetration of root system. Parish (71) 

 divides southern California into five phytogeographic areas, and in 

 consideration of the cismontane area describes the chaparral in 

 general terms. Abrams (1) emphasizes the facts of zonation, ad- 

 hering to the Merriam arrangement, and distinguishes three altitudi- 



