Changes in Species Composition of a Mixed Scots Pine - Norway Spruce Forest at the Augustow Forest During the Period 1964-1987

1991

S. 5-24

4 Tab., 11 Lit. Ang.

Unselbständiges Werk

200048865

Releves were done twice: in 1964 and 1987 exactly at the same places at the Augustow Forest, forest district of Suwalki, in a mixed fresh forest site (Calamagrostio-Piceetum community). Significant changes in species composition have been noticed after the 23 years. The changes occurred mainly at the layer of herbs and mosses, being smaller at the layer of shrubs. The number of species has decreased in all the releves. Significantly reduced in number were oligotrophic species, especially those characteristic for the Vaccinio-Piceetea class and Quercetalia pubescentis order. The communities changed their phytosociological character. As a result they became similar to deciduous fresh forest - Corylo-Piceetum association. The changes reported are a consequence of eutrophization of forest sites. The eutrophization itself was seemingly generated by the processes of regeneration and emission of nitrogen and phosphorus to the atmosphere. The observed eutrophization of forest sites suggests the necessity to change species composition of newly-regenerated forests as well as to support broadleaved species at the phase of coppices.