Reflections on lichenology: achievements over the last 40 years and challenges for the future

In June 2000, at the joint meeting of the Canadian Botanical Association and the Canadian Society of Plant Physiologists, the author of this review was presented with the George Lawson Medal for lifelong contributions to botany and was invited to prepare a special contribution for the Canadian Journal of Botany. Subsequently, an invitation was received to give the Swinscow Lecture to the British Lichen Society and the Linnean Society in London. This commentary is a written version of that January 2001 lecture and presents a personalized view of developments in those areas of lichenology studied by the author during a career in Canada and other parts of the world. Aspects touched upon include lichen identification, spore dispersal, nutrient transfer between the symbionts, water relations, and lichen strategies in particular climatic regions. The value of lichens for monitoring pollutants is noted, and the developing problem of lichen conservation is discussed. Finally, a plea is made regarding the value of field teaching and field excursions with respect to recruiting the next generation of lichenologists.