%0 Journal Article
%T Vanade salumetsade rohurinde koosseis ja seda m jutavad tegurid
%A Toivo Sepp
%A Jaan Liira
%J Forestry Studies / Metsanduslikud Uurimused
%@ 1736-8723
%D 2009
%I 
%R 10.2478/v10132-011-0067-9
%X In contemporary forests, management activities and other anthropogenic disturbances are thought to be the key factors transforming stand structure and species composition in various stand layers. The aim of this research is to compare the herb layer composition in old-aged (more than 75 years) Estonian boreonemoral forests (Aegopodium and Hepatica forest site-types) that have been influenced by various intensities of forest management and other anthropogenic disturbances. According to the survey plan a managed and a near-natural forest were studied as a pair in each sub-region of both forest site-types. In addition to management activity, stand age, geographic location and tree species composition were analysed as potential influential factors. The DCA ordination and MRPP test of herb layer composition brought out differences between the two site-types and dominant-tree-type. The MRPP test also showed a significant effect of management in general when both site-types were pooled. However, in detailed analysis, it was statistically significant only in Hepatica site-type forests. Altogether 28 species were found to have a preference for a very low or very high management intensity of a forest. The unmanaged forest sites were characterized by presence of nemoral vernal herbs e.g. Lathyrus vernus, Galeobdolon luteum, Stellaria holostea that typically grow in deciduous and mixed stands. Species characteristic for managed stands e.g. Galium album, Tussilago farfara, Veronica officinalis and V. chamaedrys, are mostly light demanding apophytes and prefer dry soils. Presumably, the high share of conifers, particularly in intensively managed Hepatica site-type forests can limit the growth of typical nemoral, especially vernal species. Forest management activities have mostly indirect effects on herb layer in old stands, via supporting the dominance of conifers, changed tree species composition, or thinned and more homogenous stand canopy. Enhanced light conditions lead to higher species richness, but also to changed composition in herb layer, e.g. supporting the abundance of graminoids. Geographic location of a forest stand also appeared to affect the understorey composition and species richness, which shows that this should be taken into account in various forest surveys. Our results suggest that silvicultural practices have to mimic more natural dynamics to achieve forest's near-natural stand structure. Such aspects as nemoral broadleaved trees, mixed stand composition and heterogeneous site conditions are important to maintain herb layer diversity.
%K forest biodiversity
%K boreonemoral forest
%K DCA
%K herb layer
%K forest management
%K species richness
%K indicator species analysis
%U http://versita.metapress.com/content/y733046820159105/?p=a63ffb3dba054972bb87061c15c19b5a&pi=1