Сучасний стан, продуктивність і созологічна цінність корінних вербово-тополевих угруповань у пониззі річки Ворскли

Abstract

На основі закладених пробних площ проаналізовано стан корінних вербово-тополевих угруповань у пониззі р. Ворскла. Встановлено, що продуктивність галерейних лісів не висока і дуже низьке природне поновлення основних видів Salix alba L., S. x fragilis L., S. caprea L., Populus alba L., P. nigrа L., P. tremula L. Галерейні вербово-тополеві ліси в пониззі р. Ворскла виконують водорегулюючу, ґрунтозахисну і созологічну функції.

На основании заложенных пробных площадей проанализировано состояние коренных ивово-тополевых сообществ в низовье р. Ворскла. Установлено, что производительность галерейных лесов не высокая и очень низкое естественное возобновление основных видов Salix alba L., S. x fragilis L., S. caprea L., Populus alba L., P. nigrа L., P. tremula L. Галерейные ивово-тополевые леса в низовье р. Ворскла выполняют водорегулирующую, почвозащитную и созологичную функции.

The article analyzes the conditions of indigenous willow-poplar groups in the lower reaches of the Vorskla river, a natural region located on the border of Forest-steppe and Steppe of Ukraine in the South of Poltava region. Most of the region is protected within the regional landscape Park «Nyzhniovorsklianskyi» (23200 ha). Specification of taxation indicators in indigenous willow-poplar groups was carried out on 20 sample plots using the standard methods of forest taxation worked out by N.P. Anuchin (1982). The height and diameter of tree trunks measuring, identification of the forest growth conditions type (according to H.I. Vasenkov, O.O. Orlov (2010), determination of species composition, age, site quality, completeness and stock of stem wood were evaluated. Natural regeneration of the areas was analyzed considering the age of stand. Complete geobotanical descriptions of sample plots were also provided. The majority of studied willow-poplar groups in the floodplain of Vorskla river are of сoppice origin, clumps of seed origin are very rare and usually can be revealed in meander flood plain. Formed willow-poplar groups were investigated on the territory of the landscape reserve «Luchkivskyi» on the right bank of the Vorskla river, in the natural boundary «Sokilske» on the floodplain of the left bank and on Vilkhovatskyi island. It was determined that indigenous willow-poplar groups in the lower reaches of the river Vorskla developed the frame, that is, gallery forests, the conservation areas of wetland biodiversity in the region. However, the conditions of these groups are satisfactory because they form mature and overmature stands and natural regeneration of key species Salix alba L., S. x fragilis L., S. caprea L., Populus alba L., P. nigra L., P. tremula L. is very low and slow due to the water level decline in the Vorskla river and ground waters. The expansion of adventive species Acer negundo L. in these groups, which is characteristic of the moist forests in the island systems of the region was confirmed. The vegetation of saucer-shaped swamps studied on Vilkhovatskyi island deserves special attention. P. nigra, P. alba, P. tremula L., S. x fragilis are dominant in the plantation composition. The undergrowth is composed of S. cinerea L. In their moss-herbaceous cover composition the species with conservation status (Lycopodium clavatum L., Ophioglossum vulgare L., representatives of genus Sphagnum) were also identified. Willow-poplar forests of the park are habitats of a number of rare species (Polypodium vulgare L., Pyrola rotundifolia L., Convallaria majalis L., Scilla siberica Haw., Equisetum hyemale L., Fragaria moschata Duch.) and species less common in the region (Thelypteris palustris Shott, Dianthus stenocalyx Juz.). Gallery willow-poplar forests in the lower reaches of the Vorskla river are habitats of rich fauna preservation. In particular, dams constructed by beavers (Castor fiber L.) were identified in the natural boundary «Sokilske». In the landscape reserve «Luchkivskyi» and on Vilkhovatskyi island the mixed-age groups of wild boar population (Sus scrofa L.) were found. On the sand dune of Vilkhovatskyi island European badger setts (Meles Meles L.) were also found. The efficiency of willow-poplar forests in the lower reaches of the Vorskla river are not high, however, they secure water regulation, soil protection and perform sozological functions. Sanitary conditions of these groups require improvement as they ate affected by wood-destroying fungus. Therefore, it is necessary to take the following measures: to stop abrupt discharge of water on Dniprodzerzhynsk hydroelectric power station; to carry out sanitary felling and remove invasive species A. negundo, because its growth causes changes of phytocenoses.