Boreal larch forests of the alliance Roso acicularis–Laricion cajanderi all. nov. in the north-east of Russia

The floodplain forests occupy river valleys in the North-East of Yakutia, Magadan region, Chukotka and Kamchatka. Studies on their dynamics, syntaxonomy and typology based on various classification principles have been undertaken throughout the last 100 years (Vasyliyev, 1956; Tyulina, 1959; Neshatayeva, 2009; The Far North…, 2010). Some studies based on the Braun-Blanquet approach were made in the past two decades (Krestov et al., 2009; Sinelnikova, 1995, 2009).

The riparian larch forests occupy a large territory within the area of continental and subcontinental climate (mean temperatures of January below –32 °C) with short vegetation period and continuous permafrost. Due to mountainous relief a local climate shows significant variation in many parameters, especially summer temperatures and precipitation (Klukin, 1970). The upper and middle parts of the Kolyma river basin within the borders of Magadan region is an area of high diversity of the larch riparian communities. Monodominant taiga stands can be found here on the floodplains of medium and high levels and also on the first and second upper river terraces where the thermic conditions are the most favorable.

This study focuses on a syntaxonomical system of the Larix cajanderi-dominated riparian forests of the North-East of Russia. The alliance Roso acicularis–Laricion cajanderi is described for the first time. The new alliance includes herb and herb-shrub forests of Equiseto–Laricetum cajanderi Sinelnikova 1995, herb-shrub larch stands of Linnaeo borealis–Laricetum cajanderi Sinelnikova 2009 and shrub-lingonberry communities of Salici bebbianae–Laricetum cajanderi Sinelnikova 2009. The main part of original data was collected in the continental part of the North-East of Russia, where the severe climatic conditions cause a very low species diversity. An original combination of the diagnostic species of associations and alliance is proposed by using the Braun-Blanquet approach.

The tree layer is formed by Larix cajanderi accompanied by following single species: Populus suaveolens, Chosenia arbutifolia, Sorbus sibirica, Salix udensis. Rosa acicularis, Ribes triste, Duschekia fruticosa, Pinus pumila, Spiraea salicifoliaare prevail in a shrub layer.  Calamagrostis langsdorffii, C. lapponica, Equisetum pratense, Chamaenerion angustifolium, Galium boreale, Lathyrus pilosus, Pyrola incarnata, Rubus arcticus dominate in the ground layer. The common species of Vaccinio-Piceetea — Linnaea borealis и Vaccinium vitis-idaea occur in the dwarf shrub layer. DCA -ordination was applied to express the positions of associations along environmental gradients. The distributive range of the alliance includes river valleys of the Northern part of the Far East to the east of Lena basin and Kamchatka Peninsula. Сhorological analysis of the floristic composition of Roso acicularis–Laricion cajanderi shows the predominance of boreal species. About 34 % of species are circumpolar, which is typical for zonal plant communities of the North-East. The syntaxonomical position of the alliance in the Vaccinio-Piceetea hierarchical system is discussed. Certain peculiarities of species-poor floristic complex and ecology of the larch riparian forests make it problematic to place the new alliance to the high units of coniferous forests of the Northern Asia — either to Abieti-Piceetalia or to Ledo palustris–Laricetalia cajanderi. Additional data obtained from the various parts of the region is needed.

The results of the research present a new data on distribution of riparian larch forests in the North-East of Russia and the geography of class Vaccinio-Piceetea in northeast Asia. Larch riparian forests are biotopes of high diversity of flora and fauna in the North-East and therefore their monitoring and conservation are needed.

Key words: vegetation, larch forests, classifi cation, Braun-Blanquet approach

Section: Articles

How to cite

Sinelnikova N. V. 2016. Boreal larch forests of the alliance Roso acicularis–Laricion cajanderi all. nov. in the north-east of Russia // Vegetation of Russia. N 28. P. 125–138. https://doi.org/10.31111/vegrus/2016.28.125

Received March 9 2015

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