Mountain Dionisiya

Created: 2014-01-24 13:53:37
Modified: 2014-01-27 12:24:12

SITE DESCRIPTION

«Mt. Dionisiya» CALM site (100 ´ 100 m) is situated in Nizhneanadyrskaya Lowland in the bottom of western slope of Mt. Dionisiya (N 64°34¢31², E 177°11¢37²). The site is located 25 km south of Anadyr city and is 35 km from the Cape Rogozhny site. The area belongs to subarctic climatic belt with transitional climate from moderately continental to marine one. According to Anadyr City weather station (25 km NNE from the site) the average annual air temperature is -7,7ºС, average annual precipitations are 312 mm. Remarkable short period deviations of both annual and monthly average air temperatures and precipitations are in common. The site is located in the area of continuous permafrost with local hydrogenous taliks. Average annual permafrost temperature is about -5º С; permafrost thickness reaches 150 m. Cryogenic crumbly-loamy bare ground patches (frost boils) formation is widely distributed in mountain bottom and plain throughout the Nizhneanadyrskaya Lowland.The study site is geomorphologically a slightly inclined (5-6º WSW) proluvial-deluvial mountain bottom with elevation about 140-145 m a.s.l. (folder with photos).

The site is vegetated by dynamically related set of moist sedge-cotton grass (Carex stans, Eriophorum polystachyon, E. scheuchzeri) stands, which coincide a network of slowly flowing water tracks, wet to mesic cotton grass tussock-moss (Eriophorum vaginatum, Sphagnum and non-Sphagnum mosses) tundra with dwarfshrubs (Betula exilis, Salix pulchra, Vaccinium uliginosum subsp. microphyllum, V. vitis-idaea var. minus, Empetrum subholarcticum, Ledum decumbens), which occupy most of the site, and some hillocks (1 to 4 m in diameter and 0.4-0.6 m high from the running water level) with mesic to xeric dwarfshrub-moss-lichen tundra (Ledum decumbens, Rubus chamaemorus, Arctous alpina, Betula exilis, Vaccinium vitis-idaea var. minus, V. uliginosum subsp. microphyllum, Empetrum subholarcticum, Dicranum sp. sp., Polytrichum sp. sp., Cetraria sp. sp., Cladina sp. sp., Cladonia sp. sp.)

SAMPLING DESIGN AND METHOD:

Permanent 100x100 m grid has been established, with 10-m intervals between grid nodes. Thaw depths were determined at each grid node (121) using a steel rod. Thaw depth measurements were made in between of tussocks or in lowerings according to the standard CALM procedure from 1996 to present except for 2006. The relative areas occupied by tundra vegetation, water tracks, and frost boils were determined, accompanied by grid leveling. The site is supplied with a temperature data-loggers measuring air and soil temperatures to the depth of 100 cm but measurements are irregular.