Plant Communities At The SRP: Plant Distribution

• What percentage of the native taxa are found on all 16 trails?

  Just 3%, 9 out of 352.

  This is half the 6% (1/16) it would be if there was an equal probability to be found on N trails. Those 9 taxa are:

  Common Name	Scientific Name
  western ragweed	Ambrosia psilostachya
  purple clarkia	Clarkia purpurea ssp. quadrivulnera
  horseweed	Conyza canadensis
  blue dicks	Dichelostemma capitatum ssp. capitatum
  fragrant everlasting	Gnaphalium canescens ssp. beneolens
  California-aster	Lessingia filaginifolia var. filaginifolia
  Spanish clover	Lotus purshianus var. purshianus
  checkerbloom	Sidalcea malviflora ssp. sparsifolia
  poison oak	Toxicodendron diversilobum

  Our two most common trees, are found on 15 routes. Coast live oak, Quercus agrifolia, is missing on the Nighthawk Loop Trail; Engelmann oak, Q. engelmannii, is missing on the Wiashal Trail.

• What percentage are found on half or more of those 16 routes?

  29%

• What percentage are found on only a single trail?

  20%; over three times more than if there was an equal probability to be found on N trails.

http://tchester.org/srp/plants/communities/5.html Comments and feedback: Tom Chester Last update: 6 November 2005.

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