Survival and Growth of Cyanolichen Transplants in Douglas-Fir Forest Canopies

Sillett, Stephen; McCune, Bruce

Abstract: "In the Oregon Cascades, epiphytic cyanolichens are abundant in old-growth forest canopies, but they accumulate very slowly in young forests. We evaluated whether epiphytic cyanolichens require old growth and/or thick, underlying moss mats to achieve normal rates of growth and mortality. We transplanted over one thousand mature thalli of two old-growth associated species (Lobaria oregana and Pseudocyphellaria rainierensis) into the crowns of Douglas- fir trees in thirteen forest stands representing four age classes: old-growth (400-700 yr), mature (140-150 yr), young (35-40 yr), and recent clear-cut. Wooden racks were used instead of trees in the clear-cuts. Half of the cyanolichen thalli were transplanted onto thick moss mats and half were transplanted onto bare bark. After one year, both species grew at least as well in younger forests as they did in old growth (20 to 30% increase in mass), but growth rates were significantly lower in clear-cuts. Mortality rates were very low (<10%) in young, mature, and old-growth forests, but high (50 to 90%) in clear-cuts. Pseudocyphellaria rainierensis grew significantly better on moss than on bare bark (30 vs 23% increase in mass). Since epiphytic cyanolichens can survive and grow in a broad range of forest age classes, silvicultural treatments that facilitate their colonization of young forests have great conservation potential."

Survival and Growth of Cyanolichen Transplants in Douglas-Fir Forest Canopies

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