PINE FOREST SUCCESSION ON SANDY RIDGES WITHIN OUTWASH PLAIN (SANDUR) IN NERUSSA-DESNA POLESIE

• Main Authors: O. I. Evstigneev, V. N. Korotkov
• Format: Article
• Language: English
• Published: Penza State University Publishing House 2016-09-01
• Series: Russian Journal of Ecosystem Ecology
• Subjects: pine forests; succession; zoochory; outwash areas
• Online Access: http://rjee.ru/en/rjee-1-3-2016-2/

Successional changes of pine forests were studied in outwash areas characterised by topography with ridges and depressions. The spatial series of pine forests of different stand ages and those that have not experienced the impact of human activities were analyzed. Pine forests in outwash areas form two successional series depending on the different ecotopes. The following successional series occurs at the tops of ridges: boreal green moss pine forest à boreal green moss – dwarf shrub forests à boreo-nemoral pine forest with admixture of birch, oak, spruce à nemoral polydominant spruce broad-leaved forest. Another successional series is formed on gentle ridge slopes: boreal polytric pine forest à boreal bilberry-polytric pine forest à boreo-nemoral pine forest with admixture of birch, oak, spruce à nemoral polydominant spruce broad-leaved forest. We show that ecotope has the leading role in the organisation of cenoses at the early stages of succession: green moss pine forests are formed at high and relatively dry relief sites (ridges) and polytric pine forests are formed on relatively wet ridge slopes. The ecotopic mosaic is complicated by the vegetation pattern created by animals (e.g., seed hawkers) at the intermediate stages of succession. Zoochoric species appear in the community: Vaccinium vitis-idaea, Convallaria majalis, Sorbus aucuparia and Quercus robur more often take root at the top of ridges; Vaccinium myrtillus, Frangula alnus and Picea abies grow on the slopes. The mosaic created by trees is imposed on a mosaic caused by ecotopes and animals at the final stages of succession: tree-fall gaps appear in the place of old dead trees with tree undergrowth. As a result, a heterogeneous community with a number of asynchronously developing gaps is formed in place of homogeneous pine forest