Vegetation Structure 

 within 4 Strata 



E 



3 



50 100 ISO 200 250 300 

 Mean Value 



LICHEN COMMUNITIES' 



Lichen communities provide information 

 about several key monitoring questions such 

 as contamination of natural resources, 

 biodiversity, and sustainability of resource 

 production. Hundreds of papers published 

 worldwide in the last century document the 

 close relation of lichen communities to air pol- 



Table 5-6 — Most common plant species 



Common name 



Sites (no.) 



Acrobolbus 

 Red alder 

 Twin flower 

 Oregongrape 

 Red blueberry 

 Western salal 

 Starflower 

 Pacific blacl<berry 

 Western hemlock 

 Sword fern 

 Douglas-fir 



9 

 9 

 10 

 10 

 10 

 13 

 13 

 16 

 16 

 17 

 20 



lution, especially nitrogen and sulfur -based 

 pollutants. Sensitivity of epiphytic lichens 

 apparently results from their lack of a cuticle 



'Adapted from: Cooperative Agreement Report: 

 Lichen communities-Pacific Northwest Pilot Study, 

 1994. Peter Neitlich, Bruce McCune, and Jeri Peck, 

 Botany Department, Oregon State University, 

 Corvalhs, OR. 1996. 9 p. 



Macrolichens on woody substrate. 



and their total reliance on atmospheric sources 

 of nutrition. Lichens thus provide a direct in- 

 dication of air pollution effects and can be in- 

 directly related to forest productivity. 



Because lichens are linked to several hu- 

 man-induced environmental stressors, they 

 may be a key indicator of general forest condi- 

 tion. To test this idea, lichens have been 

 sampled in forest health monitoring plots in 

 several regions of the United States since 1990. 

 Sampled flora is restricted to macrolichens on 

 living or standing dead woody substrates. 

 Small microlichens are excluded because they 

 are difficult to sample. These collection restric- 

 tions standardize measurements to a class of 

 substrates that can be found at all sites. For 

 example, lichens are usually abundant and 

 diverse on rocks but many field sites have no 

 surface rocks. 



Field workers collected macrolichens on 

 woody plants, excluding the 1.6-foot basal 

 portions of trees and shrubs. They estimated 

 abundance of each species using a four-step 

 scale. Accurately assigning species names to 

 collected lichens was not necessary because 

 all specimens were sent to a specialist for iden- 

 tification. 



Monitoring — 75 



