Chapter 10 - 4 Temperature : Species and Ecosystems

Figure 1. Mountainous habitats provide a wide range of temperatures. Here Ditrichum flexicaule grows in the foreground. Photo by Michael Lüth. Importance of Climate In his study of the Gulf of St. Lawrence region of Canada, Belland (2005) found that climatic variables were the most important factors determining moss species distributions, with warmth of the growing season being the most important. Acebey et al. (2003) likewise found that climate accounted for the reduced bryophyte species diversity and changes in growth forms from submontane rainforest in Bolivia to the 4-15-year-old fallows at 500-650 m elevation. In central Belgium, species composition could be predicted based on four life-history traits (minimum spore size, life expectancy, type of gametophyte, and papillose leaf cell walls) and three ecological traits (indicator values of light, temperature, and soil acidity) (Vanderpoorten & Engels 2002). For bryophytes of the eucalypt-dominated forests in Tasmania, minimum temperature in the coldest month and precipitation were the most important variables predicting bryophyte cover, richness, and composition (Pharo et al. 2005). These were reduced by the cover of vascular plants. Certainly temperature plays an important role at all stages of the life cycle. While some species are limited in their extension toward the poles by cold temperatures, others are unable to survive further away from the poles due to the heat. Grimmia torquata is an arctic-montane moss that reaches its southern limit in Newfoundland, where further