Calicioid presence in relation to substrate and tree age in forests of northeast Washington, U.S.A.

Abstract

Abstract. To further understand calicioid communities and their habitat and substrate requirements, we conducted a study on the Colville National Forest of northeastern Washington State, U.S.A. We hypothesized that calicioid composition would vary depending on age and type of substrate, and that species diversity would be higher on older trees and in older stands, as found by previous research. To test these hypotheses, we searched for calicioids on plots established by the USDA Forest Service's Forest Inventory and Analysis (FIA) program. Because individual trees on FIA plots are tagged, we could relate recorded tree species and age to calicioid composition. We investigated calicioid species diversity in relation to host species; live, dead or burnt trees; and dominant forest type. Our analyses show that calicioid abundance and diversity do increase with tree age. Thuja plicata hosted the highest number of calicioid species in our study and also had the highest rate of occupancy with 70% of all investigated boles inhabited. In an analysis of the effect of forest type (series), we found the Thuja plicata series to host the highest number of species while the Pseudotsuga menziesii series had the lowest number of species. Only 3.4% of burnt trees sampled hosted calicioids while 43.6% of unburnt trees did, suggesting that fire does negatively impact calicioid communities. Three species, Chaenotheca obscura, Chaenothecopsis haematopus, and C. nigra and were found only on snags. Of the 17 species of shrubs sampled, only Alnus, Amelanchier, Salix, and Holodiscus hosted calicioid lichen or fungi. Species that have rarely been reported from Washington include Chaenothecopsis haematopus and C. ochroleuca.