The Origin of the Desert Climax and Climate 109 



the present purpose, the most important fact is their essential 

 agreement that the entire stretch was more humid and corre- 

 spondingly cooler during the Pleistocene than it is at present, 

 though with the logical inference that this applies to the wet 

 rather than the dry phases of the several cycles. The second value 

 of the lists is to be derived from the general agreement in respect 

 to important dominants, together with their sharp reduction 

 inland at the south. The reference of these dominants to the 

 present climaxes of California furnishes the basis for testing 

 the reconstruction of the successive climaxes that have moved 

 over the desert region from the Miocene to the present. 



PLIOCENE 



RiCARDo: Last Chance Gulch 



Woodland — Chaparral — 



Pinus cembroides monophylla Robinia neo-mexicana 



Cupressus arizonica ? 



Washingtonia r filifera 



Quercus agrifolia 



Alturus-Pico 



Coniferous: Coast-montane — Chaparral — 



Sequoia sempervirens Cercocarpus parvifolius 



Pseudotsuga taxifolia Amelanchier alnifolia 



Pinus lambertiana Prunus demissa 



Libocedrus decurrens Garrya fremonti 



Pinus muricata Heteromeles arbutifolia 



Ribes nevadense Rhus laurina 



Berberis aquifolium Ceanothus integerrimus 



Smilax californica 



Pteris aquilina 



Wooodwardia radicans 



Woodland — Serai — 



Quercus agrifolia Populus trichocarpa 



Quercus douglasi Populus fremonti 



Quercus chrysolepis Salix lasiolepis 



Quercus tomentella Salix exigua 



Castanopsis chrysophylla Platanus racemosa 



Umbellularia californica Alnus rhombifolia 



Aesculus californica Fraxinus oregona 

 Arbutus menziesi 

 Pinus sabiniana 



