(A review) S. S. Kholod. Zonation in the plant cover on the Wrangel Island: syntaxonomical approach. Vegetation of Russia. 2013. N 23. P. 89–121.

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• (A review) S. S. Kholod. Zonation in the plant cover on the Wrangel Island: syntaxonomical approach. Vegetation of Russia. 2013. N 23. P. 89–121.

N. V. Matveyeva

DOI: https://doi.org/10.31111/vegrus/2014.25.116

Full article

Annotation

The reviewed paper by S. Kholod (Kholod, 2013) presents the results of detail analysis of a large set of characteristics of 46 syntaxa (associations, subassociations, variants) described on the Wrangel Isl. (Kholod, 2007) according to the of Braun-Blanquet approach. Such parameters as the number and set of syntaxa, their correlations with the elements of landscapes, and the parameters of proper syntaxa composition and structure (number of species, projective cover, horizontal structure type, geographical range of elements, above-ground mass of vascular plants) are included into the analysis. The application of the results of the vegetation classification to the large area with complex geomorphology, geology and meso- and microclimatic conditions is undeniable novelty. The purpose of the S. Kholod paper, reflected in it title, was to assess the zonal position and to conduct a zonal subdivision of the territory of Wrangel Isl. using the syntaxonomical approach. This is undoubtedly should be appreciated having in mind that our knowledge on the syntaxa distribution, both in general and focusing on optimal allocation, their assemblage in different latitudinal stripes strongly increases the objectivity of the zonal division while the use of all mentioned characteristics makes it actually geobotanical (Matveyeva, 2008). However the conclusions and the results of zonal division (shown in the scheme, see Figure), made on the basis of the comprehensive syntaxonomical analysis, induce the numerous questions and even fundamental objections.

It is worth to emphasize that islands, in general and in particular those with mountains and situated in the higher latitudes, are not the simplest objects for establishing their zonal status. This fully applies to the Wrangel Isl., where the mountains (albeit low), in most parts of the island, and the cold sea, around a relatively small area of land, leave no opportunity to manifest zonation in its correct (non-changed) form. Searching the zonal positions in the mountains is doomed to fail because this contradicts to the whole system of terms and phenomena taken into consideration when discussing the phenomenon of zonation. However, zonation is reflected not only in zonal but as well in intrazonal landscape elements, and that allows determining the zonal status of a territory when the space of zonal elements is minimized or even in their absence. The last case is not a cause to name as “zonal positions” some others that are widely represented in landscape like, for example, inside mountain valleys or carbonate substrates on Wrangel Isl. Thus, there are no grounds to call the localities, designated on the Fig. 3 in the reviewed paper (see Figure) by the letters «A», «Б», «В» and «Г» as units of zonal subdivision. Three isolated fragments under character A, that are relatively wide mountain valleys, are interpreted as the northern variant of the typical tundra subzone due to the presence the shrub willows that are absent besides this, the most heat favorable, element of landscape. However, it is the presence of the mountains is the main cause for the slightly higher air temperature, due to the specific warm winds (foehn), and optimal snow cover. Without the mountains, this effect would be impossible, and in their absence there would be no shrub thickets. So their existence is a beautiful example of «Alekhin’ feedforward rule» (Alekhin, 1951) when the specific syntaxa represent the extrazonal plant communities but in no case the presence of one zone within another. The analogous example is the location of fragments of polar desert zone and northern variants of arctic tundra subzone both in the north and south of the island. In particular this concerns the south-west island extremity on the Cape Blossom (with mean July temperature 1.1 С°), where the occurrence of polar desert syntaxa is the sequence of the hard ice conditions due to the specific configuration of the coast: long spit and thereby prolonged standing ice, which just is responsible for low summer temperatures. Hence, if the configuration of the coast in the south-west of the island would be different, neither polar desert nor the northern variant of arctic tundra in the southern half of the island would exist. But the configuration of the coastal line of the studied island has nothing to do with zonation. Also debatable is assignment to the zone of polar deserts the narrow strip in the north of the island where low summer temperatures are caused not by the amount of solar radiation / radiation balance, but the cooling effect of the ice cover persisting for most of the growing season, again due to the configuration of coastline with numerous lagoons and specificity of deepwater currents, as well as summer fogs, i. e. not with direct sequence of radiation factors. The occurrence of the communities of ass. Oncophoro wahlenbergii–Deschampsietum borealis, which has some similarities with syntaxa on the Bolshevik Isl. (Matveyeva, 2006), in wet habitats at long gentle macro-slope (mountain trail) of the northern exposure is another classic example of extrazonality, as in the case of communities with high shrub willows in mountain valleys, but with the opposite sighting.

When assessing the zonal position of small area it is necessary to link a decision with the existing subdivision of the entire biome. The Wrangel Isl. is situated in relatively low latitudes (between 70° 46′ and 71° 34′ N) where the southern (shrub) tundra subzone is represented in the middle of the Eurasian continent. The southernmost areas of the polar desert zone in circumpolar scale are located north of 75° N in the warmest Atlantic sector and north of 77° N in continental part of the north Eurasia. Similar in size with Wrangel Isl., flat islands of Novosibirskie islands archipelago located between 73° and 76° N, are referred to the arctic tundra subzone. The total cooling effect of the Arctic Ocean affects not only the island territories. The presence of tundras on the vast space of the Eurasian coast (with the exception of the Yamal, Gydan and Taymyr peninsulas) at low latitudes can be explain not only by solar radiation regime, but also by the fact that the large areas of land are cut off by sea. Otherwise, on the territory of the present tundras south of 67–69° N would been the woods. In fact, only on the Taymyr Peninsula, that is mostly extended to the north, the radiation and thermal conditions are proportionate, and therefore all subzonal boundaries are situated there more north than in the European and East Siberian sectors. The oceanic influence appears all over the whole Arctic biome but it does not prevent manifest zonal differentiation from the southern tundras to the polar deserts. This factor, common for the entire Eurasian coast, is strongly enhanced by durable ice cover owing to the specific regional conditions on Wrangel Isl. The mixed pattern of zonal units (the location of polar desert zone south of the arctic tundras and that of typical tundras inside of latter), proposed by S. Kholod, destroys all current ideas of zonation. It is obvious that these are cases of the presence of some community types (by no means zones or subzones) in alien zonal positions (that always has a clear explanation). It is not possible to agree with the author, that all differences of syntaxonomical variability within the studied territory are connected with the zonal position of its various parts. It is rather common situation when the image of zonal subdivision appears based upon for some ideas, and then all identified differences have been linked with this image rather than with the landscape peculiarities.

The usage of some terminology, concerning the names of elements of relief, the designation of zonal units, the terms of intra-landscape differentiation are also discussed with a certain amount of criticism.

Section: Critics and bibliography

How to cite

Matveyeva N. V. 2014. (A review) S. S. Kholod. Zonation in the plant cover on the Wrangel Island: syntaxonomical approach. Vegetation of Russia. 2013. N 23. P. 89–121. // Vegetation of Russia. N 25. P. 116–123. https://doi.org/10.31111/vegrus/2014.25.116

Received October 9 2014

References