Abstract
Climate change at high latitudes is predicted to be greater and more rapid than in any other region on Earth. Whilst there have been major efforts in investigating the responses of vascular plants to climate change, very little is known about the response of cryptogams (lichens and bryophytes). This is a serious omission as at high latitudes they match higher plants as contributors to species diversity, while they contribute importantly to global cryptogam species diversity. There is also increasing evidence that northern cryptogams can be sensitive indicators of particularly warming and nitrogen availability and that they are key players in feedbacks to the climate and soil hydrology. These facts contrast sharply with the poor status of our knowledge about responses of northern cryptogam diversity to global changes.The aims of the present programme are: (1) Detecting general, global trends in the response of taxonomic and functional diversity of bryophytes and lichens to global changes in cold and cool biomes. (2) Devising a functional classification of higher-latitude cryptogams relevant to global change responses. (3) Collecting data for and feeding into a GBIF-compatible cross-continental northern database with cryptogam species distributions.We will investigate cryptogam species and functional type composition and diversity in response to global change in both American and European high-latitude regions at various temporal and spatial scales by: (1) Sampling for cryptogam species and associated environmental parameters in experimental field manipulation experiments (warming, nitrogen availability, precipitation regime) in subarctic and arctic ecosystems; (2) Re-sampling in particular (sub-)arctic locations sampled adequately for cryptogam species some decades ago; (3) Sampling for cryptogam species and associated environmental parameters along natural climatic gradients in the Subarctic and Arctic (spatial analogue for temporal processes); (4) Collecting existing data for northern cryptogam species distributions (and associated site factors) from the literature and databases and transfer these, together with data from (1), (2) and (3), to a digitised database (SCANNET), to be made compatible with the international GBIF format (www.gbif.net). These data will be brought into the Dutch component of the GBIF database.
Netherlands