Карта растительности памятника садово-паркового искусства «Осиновая роща» (Санкт-Петербург)

Abstract

This article continues a series of publications devoted to vegetation mapping of existing and prospective specially protected natural areas of St. Petersburg. The “Osinovaya Roshcha” is a monument of garden art of the late XVIII–early XIX centuries. It is located on the northern border of St. Petersburg in a picturesque kame landscape, where sandy hills alternate with small bogged depressions and lakes. The landscape park of the Levashov-Vyazemsky estate was created in the forested area dominated by spruce, pine and birch. Since the 1780s oak, linden, ash, larch, fir, Siberian, Weymouth and other pines were planted there (Isachenko, 2004). A large-scale map of the actual vegetation of the “Osinovaya Roshcha” park and the adjacent territory was compiled for the first time. The natural forest, bog and meadow plant communities are characteristic features of the northern part of the area. The broad-leaved and coniferous trees, planted in the central part more than 200 years ago, have formed various plant communities, including mixed stands of local flora species and introduced trees. The southern part of the park is occupied mainly by broad-leaved introduced forest stands. Vegetation is divided into three sections in the map legend — natural, introduced, and formed by both native and introduced species. Each section represents vegetation types (or groups of types) (forest vegetation, mire vegetation, etc.); then forest communities are subdivided into classes of formations and formations, bog communities — according to the types of water-mineral nutrition. The mapped units are associations, subassociations and their variants, identified according the ecological-phytocoenotic classification. Territorial units — ecological series and combinations of plant communities — were also used in the map legend. Short-term secondary communities formed under various ecological (mainly anthropogenic) factors are subordinate to conventionally primary ones. They are indicated by indices at the legend numbers. Various types of shading were used on the map to distinguish natural and introduced vegetation. The vegetation map of the “Osinovaya Roshcha” represents a diversity of plant communities: they are forest (spruce, pine, birch) and bog (lowland, transitional, upland) communities typical of the region, as well as old-growth larch (Larix sibirica) and broad-leaved (oak, linden, elm, mixed composition) forests formed by introduced trees. Last ones are rare for the region. The plant community of Carex brizoides, found in the park, is of great interest among the communities of herbaceous plant introducers. This sedge is a rare species for St. Petersburg and the Leningrad region, which probably like the Poa chaixii was used for sodding the park soils.