| Summary: | Effects of stand type on ground lichen height and species richness in boreal forests. P. contorta as an alternative to P. sylvestris in terms of providing a suitable habitat Maria Johansson Abstract Lichen-rich forests are essential to reindeer but up to 50 % of the lichen-rich areas in Sweden have been lost since the 1950s. Ground lichens thrive in pine-heaths and with an increasing area of plantations of the non-native tree species Pinus contorta, as an alternative to the native P. sylvestris, it is important to investigate if P. contorta can provide such an optimal habitat to ground lichens. The purpose of this study was to assess if forest characteristics, such as tree density, canopy cover and production capacity, affect the abundance and growth of five lichen species (Cladonia rangiferina, C. arbuscula/mitis, C. stygia, C. stellaris and Cetraria islandica) and whether these characteristics differ between forests dominated by P. contorta and forests dominated by P. sylvestris. Fieldwork was conducted in Norrbotten and Västerbotten on sample plots previously used by the Swedish National Forest Inventory (SNFI). The statistical analysis was based on data collected from 22 sample plots, 11 of each forest type, visited during July and September 2015. No statistical significant differences were found between forest characteristics of the two forest types, and none of the forest characteristics were found to relate to lichen height. Forest age did not seem to have an effect on ground lichens, while both canopy cover and production capacity were found to negatively relate to the proxy for lichen biomass as well as the abundance of the most common lichen species, C. rangiferina and C. arbuscula/mitis. The result suggests that a shadier canopy as well as a higher production capacity contributes to a reduced distribution of ground lichens. Keywords: Ground lichens, Pinus contorta, Pinus sylvestris, forest characteristics, forestry, reindeer husbandry
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