THE WOODLAND CLIMAX. 



193 



influencing it; that its importance is equally divided between wet and dry 

 seasons, the greater excess of supply over loss in the forest during the growing 

 season explaining the size and luxuriance of the plants living there, and the 

 higher evaporation rate in the chaparral during the dry season, with equally 

 severe soil-moisture conditions, accounting for the absence of mesophytic 

 species in that habitat." 



SOCIETIES. 



The winter rainy season of the Coast region causes a corresponding early 

 development of societies and necessitates a readjustment of the aspects. 

 Because of favorable temperatures, societies appear in southern California as 

 early as January and the first aspect attains its maximum in February or 

 March. In order to maintain the usual seasonal relations, this is regarded as 

 the prevernal aspect. It is followed by a late spring or vernal aspect, and this 

 by one in which summer and autumn relations are more or less combined. 

 With few exceptions, the societies listed are perennial. Some of them bloom 

 through more than one aspect, but these are listed in the first one in which 

 they appear. A large number of annuals occur, especially in southern Cali- 

 fornia, but these are either members of subsere communities, or they are 

 desert annuals, most of which have already been given under the desert scrub. 

 It is practically certain that some of the societies listed below have been 

 derived from the original Stipa grassland, but the exact determination of these 

 must await further study. 



Prevernal Societies: 



Brodiaea capitata. 

 Brodiaea congesta. 

 Brodiaea grandiflora. 

 Brodiaea minor. 

 Sisyrinchium bellum. 

 Eriogonum compositum 

 Eschscholtzia californica. 

 Delphinium parryi. 

 Sidalcea malviflora. 

 Viola pedunculata. 

 Sanicula bipinnata. 

 Sanicula bipinnatifida. 

 Dodecatheon clevelandii. 

 Castilleia foliolosa. 

 Wyethia glabra. 

 Wyethia helenioides. 



Vernal Societies: 



Calochortus luteus. 

 Calochortus venustus. 

 Calochortus splendens. 



Vernal Societies — continued. 

 Hosackia glabra. 

 Pentstemon heterophyllus. 

 Pentstemon azureus. 

 Lupinus formosus. 

 Lathyrus splendens. 

 Lathyrus vestitus. 

 Astragalus crotalariae. 

 Astragalus leucopsis. 

 Eriophyllum confertiflorum. 

 Eriophyllum lanatum. 

 Phacelia ramosissima. 

 Castilleia affinis. 

 Delphinium hesperium. 

 Gnaphalium bicolor. 

 Gnaphalium decurrens. 

 Poly gala californica. 

 Haplopappus linearifolius. 

 Eriogonum nudum. 

 Oxalis corniculata. 

 Agoseris retrorsa. 

 Agoseris grandiflora. 



Vernal Societies — continued. 

 Hypericum concinnum. 

 Scrophularia californica. 

 Convolvulus occidentalis. 

 Paeonia brownii. 

 Wyethia angustifolia. 

 Corethrogyne filaginifolia. 

 Galium andrewsii. 

 Lomatium tomentosum. 



Estival Societies: 



Artemisia heterophylla. 

 Achillea millefolium. 

 Solidago californica. 

 Gutierrezia sarothrae. 

 Senecio douglasii. 

 Zauschneria californica. 

 Verbena prostrata. 

 Verbena stricta. 

 Opuntia engelmannii. 

 Opuntia basilaris. 



THE WOODLAND CLIMAX. 



PINUS-JUNIPERUS FORMATION. 



Nature. — The woodland formation consists of small trees capable of form- 

 ing a canopy and hence of constituting a real though low forest. A number of 

 reasons combine to make it the most difficult of all formations to delimit and 

 to characterize. The first of these lies in the ability of practically all the 

 dominants to vary from trees 30 to 50 feet high to shrubs of 10 to 20 feet, and 

 in some cases to bushes of less than 10 feet. As trees they often give the 



