, 2002a, DeLuca et al., 2002b and Zackrisson et al., 2004). Assuming Alpelisib concentration wildfires

consume approximately 30–60% of the total N in the O horizon ( Neary et al., 2005) (which in this case would be about 200 kg N ha−1), the annual contribution of N by feathermosses could have replenished this N loss in about 200 years (100 years of forest succession followed by 100 years of N2 fixation). Regular burning would have consumed the moss bottom layer ( Payette and Delwaide, 2003) and greatly reduced the presence of juniper ( Diotte and Bergeron, 1989 and Thomas et al., 2007) resulting in an un-surmountable loss of N, the loss of the predominant N source, and ultimately the loss of the capacity to support stand N demands (approximately 30 kg available N ha−1 yr−1) of a mature Scots pine, Norway spruce forest of ( Mälkönen, 1974). Reindeer do Olaparib cell line not eat feathermosses, thus their presence on the forest floor was likely of no value to reindeer herders and may have

been looked upon as a nuisance. Consequently, the use of fire to transform dwarf-shrub/moss dominated forests into lichen dominated heaths to provide reindeers with winter grazing land would rather be essential for, and not be in conflict with, the traditional way of living for reindeer herders. The findings of these studies build upon the thesis put forth by Hörnberg et al. (1999) which suggested that the spruce-Cladina forests were altered by past land management and specifically repeated use of fire. The recurrent fires led to the loss of nutrient capital on these sites and thereby reducing the potential for pines to regenerate and recolonize these otherwise open forest stands.

This is further www.selleck.co.jp/products/Temsirolimus.html supported by previous findings on the black spruce-Cladina forests within the permafrost zone of North America which suggest that repeated disturbance, predominantly fire, induced a change in structure, composition and function of boreal coniferous stands ( Girard et al., 2009, Payette et al., 2000 and Payette and Delwaide, 2003). Natural fire frequency due to lightning strikes in this region in northern Sweden is relatively low ( Granström, 1993) and historical fire intervals mainly driven by climate were likely 300 or more years ( Carcaillet et al., 2007). Human use of fire as a management tool apparently altered historical vegetative communities, reduced nutrient capital, and ultimately created conditions that have perpetuated the vegetative communities present in this region today. Even in subarctic areas of Fennoscandia, that are often considered to be the last wilderness of northern Europe, impact by low technology societies has consequently lead to profound changes in some ecosystems that were carefully selected due to some specific condition that made them manageable by simple means to serve a specific purpose; e.g. use of fire to provide winter grazing land.