%0 Journal Article
%T Harjumaa loometsad
%A Jaanus Paal
%A Elle Rajandu
%A Igna Rooma
%J Forestry Studies / Metsanduslikud Uurimused
%@ 1736-8723
%D 2009
%I 
%R 10.2478/v10132-011-0068-8
%X Alvar forests grow on shallow soils (with thickness up to 30 centimetres) formed on limestone, gravel, grit or shingle. Due to their peculiar content of flora and communities structure these forests represent one of the most exiting vegetation types around the Baltic Sea. In the current study vegetation and soils of 56 alvar forests in Harjumaa district, N and NW Estonia, were analysed. Eight community types were established: (i) Inula salicina-Potentilla fruticosa-Pinus sylvestris, (ii) Carex panicea-C. cespitosa-Pinus sylvestris-Betula pubescens, (iii) Filipendula vulgaris-Brachypodium pinnatum-Pinus sylvestris, (iv) Brachypodium pinnatum-Calamagrostis arundinacea-Picea abies-Pinus sylvestris, (v) Hepatica nobilis-Brachypodium pinnatum-Picea abies-Pinus sylvestris, (vi) Paris quadrifolia-Anemone nemorosa-Fraxinus excelsior, (vii) Mercurialis perennis-Picea abies, and (viii) Pulmonaria obscura-Viola mirabilis-Betula pendula-Picea abies. The 2nd community type represents the Sesleria alvar forest site type (FST) habitats, while communities of the 1st, 3rd and 4th types belong to the Calamagrostis alvar FST. The latter communities grow mainly on medium thick or thin Calcaric Skeletic Regosols, less frequently on thin Renzic Leptosols or on other types of soil. Other communities qualified by forest inventory as alvar forests factually belong to the boreo-nemoral Hepatica FST (communities of 5th type) and Aegopodium FST (communities of 6th, 7th and 8th types). A strong positive correlation between the soil humus horizon specific surface area and pHKCl with deciduous trees basal area and height of the 1st sublayer of trees was established, between the humus horizon CaCO3 content and spruce basal area a negative correlation exists. Alvar forests are characterized by remarkably high species diversity deriving first of all from the number of field and moss layer species. In tree layer altogether 13 species, in bush layer (incl. saplings) 48 species and in field layer 229 species were recorded. In moss layer, on tree stems and branches 100 species of bryophytes were registered. The field layer species diversity is usually higher in pine forests where tree crowns do not shadow the surface so much as in stands dominated by spruce or deciduous trees. The number of species in all layers, except moss layer, depends significantly from the factor, Type group of communities' reflecting in integrated form effect of communities structure. Diversity of field layer species is negatively affected additionally by the ratio of carbon and nitrogen content in soil humus horizon, and species number of moss layer by abundance of Pinus trees.
%K alvar forest
%K community types
%K General Regression Analysis
%K Leptosols
%K Regosols
%K species diversity
%U http://versita.metapress.com/content/8614hv416212t1kl/?p=a63ffb3dba054972bb87061c15c19b5a&pi=2