BiodiversityandConservation 10: 2153–2166, 2001. © 2001 KluwerAcademicPublishers. PrintedintheNetherlands. Bryophyte and vascular plant species richness in boreo-nemoral moist forests and mires NELE INGERPUU 1,2,∗ , KAI VELLAK 1,2 , TOOMAS KUKK 1,2 and MEELIS PÄRTEL 1,3 1 InstituteofBotanyandEcology,UniversityofTartu,40LaiStr.,51005Tartu,Estonia; 2 Instituteof ZoologyandBotany,EstonianAgriculturalUniversity,181Riiastr.,51014Tartu,Estonia; 3 Department ofBiology,UniversityofRegina,Regina,Saskatchewan,CanadaS4S0A2;*Authorforcorrespondence (e-mail:nele@zbi.ee;fax:+372-7-376222) Received 3 July 2000; accepted in revised form 25 January 2001 Abstract. We compare species richness of bryophytes and vascular plants in Estonian moist forests and mires. The material was collected from two wetland nature reserves. Bryophyte and vascular plant spe- cies were recorded in 338 homogeneous stands of approximately 1 ha in nine forest and two mire types. Regional species pools for bryophytes and vascular plants were significantly correlated. The correlations between the species richnesses of bryophytes and vascular plants per stand were positive in all community types. The relative richnesses (local richness divided by the regional species pool size) were similar for bryophyte species and for vascular plant species. This shows that on larger scales, conservation of the communities rich in species of one taxonomic plant group, maintains also the species richness of the other. The minimum number of stands needed for the maintenance of the regional species pool of typical species for the every community type was calculated using the species richness accumulation curves. Less stands are needed to maintain the bryophyte species pools (300–5300 for bryophytes and 400–35 000 for vascular plants). Key words: bryophytes, conservation of species diversity, species accumulation curve, species pool, vascular plants Introduction The importance of maintaining species richness has become more pressing in recent years, especially due to the loss and fragmentation of natural habitats (Fischer and Stöcklin 1997; Rozensweig 1999). In Estonia, the main attention in plant species richness studies has been on grasslands (Pärtel and Zobel 1995, 1999; Zobel et al. 1996; Pärtel et al. 1998). Plant species richness in forests and wetlands has been studied much less (Zobel 1993). Forests and mires form the typical climax vegetation for the boreo-nemoral zone (Sjörs 1963) although natural forests and wetlands have almost disappeared from Western Europe due to agriculture and forest cultivation (Navid 1994; Noss and Csuti 1994). In Estonia the situation is much better, 47% of the territory of Estonia is covered by woodland (Varblane 1998) and 23% by mires (Orru et al. 1992). Land ownership reform has intensified forest utilization in Estonia