Evaluation frameworks and conservation system of Latvian forests

Since the 1990s the forest conservation system in Latvia has developed in two parallel trends. This reflects both traditional application of central European phytosociology by explicit forest communities (at least 19 associations in Latvian forests) and the recently appreciated method of key-habitats in forests. It consists of two attributes: indicator species-habitat specialists and certain abiotic structures whose persistent presence on the spot is limited by intactness, time-scale and natural disturbances. Following the interpretation manual of habitats in the European Union, eight forest habitats deserve particular conservation in Latvia. Altogether 8% of Latvian forests are formally protected, although only 1.5% meet the World Conservation Union Category '1' where all human intervention must be excluded or minimized. Original analysis of Latvian forest communities by their phytosociological standard and a comparison with similar assemblages elsewhere suggest that four forest groups deserve all-European conservation priority in Latvia because of intactness and large stands still survived or because of narrow distribution area. These are: Alnus glutinosa-Betula spp.-Fraxinus excelsior wetlands (ca. 3000 ha in various formal reserve networks), northern outposts of mixed riverine hardwood forests on the bank slopes and in semi-permanently moist ravines (ca. 240 ha in reserves), floodplain and riverine Quercus robur relic woodlands in eastern Latvia (ca. 120 ha in reserves) and dry Fennoscandian-Baltic Pinus sylvestris woodlands on dolomites and limestones (no areas formally protected by law yet). Preliminary inventory of woodland key-habitats suggests that only 3% of Latvian forests can meet the desired criteria. This method, based on 53 indicator species indicating certain habitat properties and 25 abiotic structures and stand features, has been found a valuable tool in forestry practice to evaluate the forest before any logging takes place and to monitor spatial changes of biodiversity.