Lichenological evidence for the recognition of inland rain forests in western North America
Article first published online: 2 JUN 2005
Journal of Biogeography
Volume 32, Issue 7, pages 1209–1219, July 2005
How to Cite
Goward, T. and Spribille, T. (2005), Lichenological evidence for the recognition of inland rain forests in western North America. Journal of Biogeography, 32: 1209–1219. doi: 10.1111/j.1365-2699.2005.01282.x
- Issue published online: 2 JUN 2005
- Article first published online: 2 JUN 2005
- British Columbia;
- summer moisture deficit;
- temperate rain forests
Aim The coastal temperate rain forests of north-western North America are internationally renowned as the archetypal expression of the temperate rain forest biome. Less well documented is the existence of somewhat similar forests 500–700 km inland on the windward slopes of the Columbia and Rocky Mountains. Here we attempt to show that these inland ‘wetbelt’ forests warrant rain forest status.
Location North-western North America.
Methods We use tree-dwelling macrolichens to assess the degree of environmental congruence between the coastal temperate rain forests and their inland counterparts.
Results We report three key findings: (1) 40% of oceanic, epiphytic macrolichens found in Pacific coastal rain forests occur also in inland regions; (2) epiphytic species richness decreases with decreasing latitude, such that roughly 70% of disjunct oceanic species are restricted to regions north of 51° N; and (3) the southward decline in lichen diversity is correlated with a parallel decrease in summer precipitation, but not with mean annual precipitation.
Main conclusions These observations are consistent with the recognition of an inland rain forest formation between 50 and 54° N. Inland rain forests represent a small, biologically significant ecosystem whose continued fragmentation and conversion to tree plantations warrant close scrutiny.