Trade-off between reproduction and growth in the foliose old forest lichen Lobaria pulmonaria

A data set of growth in 600 Lobaria pulmonaria transplants in three successional forest stands was reanalysed after a subsequent quantification of their reproductive effort. This epiphytic lichen reproduces mainly by asexual and symbiotic diaspores (soredia and/or isidia) that simultaneously disperse the fungal and algal partners. L. pulmonaria showed a clear trade-off between growth and reproductive efforts. Increased reproductive efforts decreased the area growth to a larger extent than the weight gain, meaning that reproduction increased with increasing lobe thickness and presumably increasing lobe age. The growth reduction caused by reproduction is so strong that future ecological and physiological lichen studies should consider the reproductive stage or standardize the amount of asexual diaspores in future experiments. (c) 2006 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.