redwoods exert a strong influence on determining which plants 

 can grow under them. Redwood forests tend to be densely shaded 

 at the ground level and also to have thick mats of semi-decom- 

 posed fallen redwood leaves and twigs. Because of the shading 

 and the dense cover of fallen leaves, rather few herbaceous plants 

 can flourish under redwood trees. Among these are Redwood 

 Sorrel {Oxalis oregana), Inside-out Flower {Vancouveria parvi- 

 flora). Sword Fern {Polystichum munitum) and a few shrubs such 

 as Salal {Gaultheria shallon). Evergreen or California Huckleberry 

 {Vaccinium ovatum), and some other species. 



Certain features of the Redwood Forest also support the 

 contention of some plant ecologists that in many instances the 

 idea of "community" is rather arbitrary. Obviously, wherever 

 you encounter a large natural stand of redwoods you are, by 

 definition, in a redwood forest. A redwood forest is defined by 

 the presence of a single dominant species. One might assume, 

 however, that a number of "fellow travellers" of the Coast Red- 

 wood also are generally restricted to redwood forest. But this 

 is not true. If you examine the distribution of all other plant 

 species that generally are associated with redwoods you will find 

 that each of these is widespread in areas where the Coast Red- 

 wood does not occur, and, furthermore, that there are no striking 

 parallelisms among the ranges of these individual species. 



Examples of other Coniferous Forest plant communities 

 dominated by one or a few tree species are the Closed-Cone Pine 

 Forest (dominated in various areas by Bishop Pine, Pinus muri- 

 cata; or Monterey Pine, P. radiatd) and the Montane Forest 

 (dominated in various areas by the Ponderosa Pine, Pinus pon- 

 derosa; Coulter Pine, P. coulteri. Sugar Pine, P. lambertiana, 

 Incense Cedar, Calocedrus decurrens; Douglas Fir, Pseudotsuga 

 menziesii; and/or a few other coniferous tree species). 



The aggregations of plants in some parts of CaHfornia cannot 

 be recognized as belonging to any plant community. In many 

 areas, there are mixtures of species that are characteristic of 

 two or more different plant communities. One solution to this 

 problem is to continue to invent new names to designate these 

 associations, but ultimately this would lead to a confusingly large 

 number of plant communities. Perhaps the most reasonable al- 



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