Global change and the functional diversity of cryptogams in northern biomes

Climate change in the (Sub)Arctic is expected to be more extreme and rapid compared to other regions on Earth. At these northern latitudes, cryptogams (bryophytes and lichens) are the dominant vegetation component both in terms of abundance and biodiversity, fulfilling important ecosystem functions such as regulation of hydrology, carbon balance, nitrogen fixation and preservation of permafrost. While responses of vascular plants to climate have been studied in much detail, cryptogams have been mostly neglected in these investigations. Here I present a detailed study on cryptogam responses to climate (change), focusing not only on their diversity and abundance in contrasting ecosystems, but also on the consequences these changes may have for the nutrient and carbon economy of the cryptogam community. I focus especially on nutrient cycling processes that are related to the ‘afterlife effects’ of traits of the cryptogams, through analyzing interspecific variation in nutrient resorption from senescing tissues, quality of the litter remaining and its consequent decomposability.