Diversity and distribution of vascular plants within the treeline ecotone in Mount Iremel (Southern Urals, Russia)

Study Extent

The study was carried out in the Southern Urals, Russia, within the Iremel mountain group, at the different slopes of Bol’shoy (54° 31.2’ N, 58° 50.5’ E) and Malyy (54° 33.1’ N, 58° 53.5’ E) Iremel. A total of 700 sampling plots (672 plots of 0.5×0.5 m and 28 plots of 10×10 m) were established in three types of biotopes: 300 plots in a birch-spruce sparse forest, 300 plots in a spruce forest with fragments of meadow plant communities, and 100 plots in a birch-spruce shrub forest.

Sampling

The sampling process included direct naked eye observations of all vascular plant species in ground vegetation in sampling plots of two sizes (0.5×0.5 m and 10×10 m). Each plot was described according to the common practice of geobotanical description. A large number of plots (700 in total) make it possible to take into account the irregularity in distribution of plant species within the study sites. The use of small-sized sampling plots allows obtaining quantitative data (frequency of species occurrences) to estimate the species abundance.

Quality Control

Identification of plant species was carried out mostly in the field; specimens with controversial species affiliation were herborized and identified later in a laboratory. Identification was cross-checked by specialists of the Institute Botanical Garden of the Ural Branch of the Russian Academy of Sciences (IBG UB RAS). About 90% of all occurrences of vascular plants have been identified to species.

Method steps

1. Vertical transects were established across the treeline ecotone at the south-western and southern slopes of Malyy Iremel and the north-eastern slope of Bol’shoy Iremel (three transects on each slope, nine transects in total). At the southern slope of Malyy Iremel and the north-eastern slope of Bol’shoy Iremel, two elevation levels were selected (the corresponding biotopes are birch-spruce sparse forest and spruce forest with fragments of meadow plant communities). At the south-western slope of Malyy Iremel, three elevation levels were selected (the corresponding biotopes are birch-spruce sparse forest, birch-spruce shrub forest, and spruce forest with fragments of meadow plant communities). Three sampling sites 20×20 m (also referred to as macro-plots (=locationID), 21 in total) were placed within each elevation level. The central points of the sampling sites were positioned at a distance of 50–70 m from each other. At each elevation level, within two sampling sites, 12 plots with a size of 1×1 m were located (total number 168), within which, in turn, four sampling plots with a size of 0.5×0.5 m were placed (total number 672; the first method for assessment of plant species composition). The third sampling site within each elevation level was divided into four sampling plots of 10×10 m (total number 28; the second estimation method). All observations of plant species composition were carried out during July 2003.

General taxonomic coverage is 1 phylum, 4 classes, 22 orders, 30 families, 59 genera, 70 species of vascular plants.

1. Tracheophyta
   rank: phylum
2. Liliopsida
   rank: class
3. Magnoliopsida
   rank: class
4. Pinopsida
   rank: class
5. Polypodiopsida
   rank: class
6. Apiales
   rank: order
7. Araliales
   rank: order
8. Asparagales
   rank: order
9. Asterales
   rank: order
10. Brassicales
    rank: order
11. Caryophyllales
    rank: order
12. Dipsacales
    rank: order
13. Ericales
    rank: order
14. Fabales
    rank: order
15. Gentianales
    rank: order
16. Geraniales
    rank: order
17. Lamiales
    rank: order
18. Liliales
    rank: order
19. Malpighiales
    rank: order
20. Myrtales
    rank: order
21. Oxalidales
    rank: order
22. Pinales
    rank: order
23. Poales
    rank: order
24. Polypodiales
    rank: order
25. Ranunculales
    rank: order
26. Rosales
    rank: order
27. Saxifragales
    rank: order
28. Apiaceae
    rank: family
29. Asparagaceae
    rank: family
30. Asteraceae
    rank: family
31. Brassicaceae
    rank: family
32. Campanulaceae
    rank: family
33. Caprifoliaceae
    rank: family
34. Caryophyllaceae
    rank: family
35. Crassulaceae
    rank: family
36. Cupressaceae
    rank: family
37. Cyperaceae
    rank: family
38. Dryopteridaceae
    rank: family
39. Ericaceae
    rank: family
40. Fabaceae
    rank: family
41. Gentianaceae
    rank: family
42. Geraniaceae
    rank: family
43. Hypericaceae
    rank: family
44. Juncaceae
    rank: family
45. Liliaceae
    rank: family
46. Onagraceae
    rank: family
47. Orobanchaceae
    rank: family
48. Oxalidaceae
    rank: family
49. Plantaginaceae
    rank: family
50. Poaceae
    rank: family
51. Polygonaceae
    rank: family
52. Primulaceae
    rank: family
53. Ranunuculaceae
    rank: family
54. Rosaceae
    rank: family
55. Rubiaceae
    rank: family
56. Salicaceae
    rank: family
57. Valerianaceae
    rank: family

The Iremel mountain group is located in the region of the highest elevations of Southern Urals within the Iremel-Avalyak mountain region. On the joint base of the Iremel mountain range, two peaks rise – Bol’shoy and Malyy Iremel (1582 and 1450 m above sea level, respectively). The elevation range of 1100–1150 m above sea level is occupied by spruce and spruce-birch sparse forests of a park type as well as tall-herb meadows dominated by Koenigia alpina and Bistorta officinalis; a range of 1350–1400 m is mainly occupied by spruce and birch shrub forests with low-herb meadows. Elevations above 1400 m occupied by mountain tundra. The herb–moss tundras prevail, but there are also stony, lichen, dwarf shrub–moss, and complex tundra types. The main tree species forming the upper forest line are Picea obovata and Betula pendula spp. tortuosa. Sampling plots were placed at an altitude of 1200–1350 m above sea level within the present-day ecotone of the upper forest line. At the southern slope of Malyy Iremel and the north-eastern slope of Bol’shoy Iremel plots were located in two types of biotopes (birch-spruce sparse forest and spruce forest with fragments of meadow plant communities); at the south-western slope of Malyy Iremel in three types of biotopes (birch-spruce shrub forest, birch-spruce sparse forest and spruce forest with fragments of meadow plant communities).