Encyclopaedia Britannica > Volume 21, ROT-Siam

76
Flora.
RUSSIA
[flora.
country are highways for sledges. The "Volga remains frozen for
a period varying between 150 days in the north and 90 days at
Astrakhan, the Don for 100 to 110 days, and the Dnieper for 83 to
122 days. On the Diina ice prevents navigation for 125 days, and
even the Vistula at Warsaw remains frozen for 77 days. The
lowest temperatures are experienced in January, in which month
the average is as low as 20° to 5° Fahr. throughout Eussia ; in the
west only does it rise above 22°. On the whole, February and
March continue to be cold, and their average temperatures rise
above zero only on the Black Sea coast. Even at Kieff and Lugah
the average of March is below 30°, while in central Eussia it is 25°
to 22°, and as low as 20° and 16° at Samara and Orenburg.
Isotherms.—All Eussia is comprised between the isotherms of 32°
and 54°. On the whole, they are more remote from one another
than even on the plains of North America, those of 46° to 32° beino-
distributed over 20 degrees of latitude. They are, on the whole,
inclined towards the south in eastern Russia ; thus the isotherm of
39° runs from St Petersburg to Orenburg, and that of 35° from
TorneA to Uralsk. The inflexion is still greater for the winter
isotherms. Closely following one another, they run almost north
and south ; thus Odessa and Konigsberg are situated on the same
winter isotherm of 28° ; so also St Petersburg, Orel, and the
mouth of the Ural river (about 20°) ; Mezen and Ufa (9°). The
summer isotherms cross the above nearly at right angles, so that
Kieff and Ufa, Warsaw and Tobolsk, Eiga and the upper Kama
have the same average summer temperatures of 64°, 62J°, and 61°.
Winds, Moisture, Rainfall.—The investigation of the cyclones
and anticyclones in Eussia cannot as yet be regarded as completed.
It appears, however, that in January the cyclones mostly cross
north-west Eussia (north of 55° and west of 40° E. long.), following
directions which vary between north-east and south-east. In July
they are displaced towards the north, and cross the Gulf of Bothnia,
while another series of cyclones crosses middle Eussia, between 50°
and 55° N. laC The laws of the anticyclones are not yet estab¬
lished. The winds closely depend on the routes followed by both.
Generally, however, it may be said that alike in January and in
July west and south-west winds prevail in western Eussia, while
eastern ones are most common in south-eastern Eussia; northern
winds are most common on the Black Sea coast. The strength of
the wind is greater, on the whole, than in the continental parts of
western Europe, and it attains its maximum in winter. Terrible
gales blow from October to March, especially on the southern
steppes and on the tundras. Gales with snow {burans, myatels),
lasting from two to three days, or northerly gales without snow|
are especially dangerous to man and beast. The average relative
moisture reaches 80 to 85 per cent, in the north, and only 70 to 81
per cent, in southern and eastern Russia. In the steppes it is only
60 per cent, during summer, and still less (57) at Astrakhan. The
average amount of cloud reaches 73 to 75 per cent, on the White
Sea and in Lithuania, 68 to 64 in central Russia, and only 59 to 53
in the south and south-east. The amount of rainfall is shown in
the subjoined table (III.):—1
Archangel...
Petrozavodsk
Helsingfors..
St Petersburg..
Bogoslovsk
Dorpat
Kostroma
Ekaterinburg..
Kazan
Moscow
Vilna
"Warsaw
Orenburg
Kursk
Kieff
Tsaritsyn
Lugan
Odessa
Astrakhan
Sebastopol
Poti
Tiflis
North
Latitude.
64 34
61 47
60 10
59 57
59 45
56 22
57 46
56 49
55 47
55 45
54 41
52 14
51 45
51 44
50 27
48 42
48 27
46 29
46 21
44 37
42 9
41 42
Height
above
Sea in
Feet.
30
160
40
20
630?
220
360
890
260
520
390
360
360
690
590
100
200
270
-70
130
0
1440
Average Temperatures.
Year. January. July,
327
36- 4
39-0
38- 4
29-4
39- 5
37- 3
32-8
37-2
39-0
43- 8
44- 9
37-9
41-0
44-2
44- 4
45- 6
49-0
49-0
53- 7
58-4
54- 5
7'6
11-8
19-5
15-0
-3-8
17'6
9-4
2-2
7-0
12-1
22-1
23- 8
47
137
2U0
13-4
17-0
24- 8
19-2
35-2
39-0
33-0
60-6
62-1
61- 5
64- 0
62- 5
631
66'3
63- 5
67-3
66-0
65- 6
65- 4
70-9
67-2
66- 3
74-6
73-0
72- 3
77-9
73- 8
73-3
757
Average
Minimum. Maximum,
-33
-24
-17
-20
-47
-14
-27
-33
-25
-22
-10
- 2
-28
-19
-13
-18
- 3
-14
+ 10
+ 25
+ 10
84
86
80
83
87
85
88
87
89
88
85
86
96
91
89
95
89
97
93
93
96
Full
Range of
Ther¬
mometer.
147
135
112
135
150
124
140
142
129
144
110
123
147
139
122
146
108
135
105
88
100
First
Frosts.
26 Sept.
15 Oct.
20 Sept.
7 Oct.
21 Oct.
1 Oct.
7 Oct.
17 Oct.
18 Oct.
19 Oct.
11 Oct.
10 Nov.
27 Oct.
Last
Frosts.
20 May
8 May
14 May
3 May
14 May
27 April
26 April
27 April
7 April
17 April
11 April
31 Mar.
5 April
Number of Days
per Year.
Bright.
Cloudy.
Average Rainfall
in Inches.
Year.
12 Jan. 1 Mar.
18 Nov. 115 Mar.
23
35
43
40
40
35
23
40
34
64
67
69
199
148
94
145
138
i42
175
154
132
124
112
114
16-2
19-6
18- 3
15-8
24-9
19- 4
14-1
18-0
23-0
22-8
17-1
19- 9
20- 1
14- 3
15- 6
57
15-4
64-9
19-3
November
to March.
4- 3
7'3
5'3
31
7'3
5- 2
1-6
5-4
7-3
6'7
5- 8
5 6
6- 0
4-3
5'4
1-5
7-2
23-4
4-3
The flora of Russia, which represents an intermediate link
between those of Germany and Siberia, is strikingly uniform over
a very large area. Though not poor at any given place, it appears
so if the space occupied by Eussia be taken into account, only
3300 species of phanerogams and ferns being known. Four great
regions may be distinguished the Arctic, the Forest, the Steppe,
and the Circum-Mediterranean,
The Arctic Region comprises the tundras of the Arctic littoral
beyond the northern limit of forests, which last closely follows the
coast-line, with bends towards the north in the river valleys (70°
N. lat. m Finland, on the Arctic Circle about Archangel, 68° N.
lat. on the Urals, 71° on "West Siberia). The shortness of the
summer, the deficiency of drainage, and the thickness of the layer
ol soil which is frozen through in winter are the elements which go
to the making of the characteristic features of the tundras Their
flora is far nearer those of northern Siberia and North America
than that of central Europe. . Mosses and lichens cover them, as
also the birch,_ the dwarf willow, and a variety of shrubs ; but
where the soil is drier and humus has been able to accumulate, a
variety of herbaceous flowering plants, some of which are familiar
xooa Yestcrn ®ul'°Pe> make their appearance. Only from 275
to 280 phanerogams are found within this region.
^^ Forest Region of the Russian botanists occupies the greater
part of the country from the Arctic tundras to the Steppes, and
it maintains over this immense surface a remarkable uniformity
of character. M. Beketoff subdivides it into two portions—the
forest region proper, and the “Ante-Steppe” (jrredstepie). The
northern limit of the Ante-Steppe would be represented by a line
drawn from the South Pruth through Zhitomir, Kursk, Tamboff
and Stavropol-on-Volga to the sources of the Ural. But the
forest region proper itself presents a certain variety of aspect in
its northern and southern parts, and must in turn be again sub¬
divided into two parts—the coniferous region and that of the oak
forests,—these being separated by a line drawn through Pskoff,
Kostroma, Kazan, and Ufa. Of course, the oak occurs farther
north than this, and conifer forests extend farther south, advancing
even to the border-region of the Steppes ; but this line must still
be considered as important. To the north of it we have dense
forests, covering very large areas, and interrupted oftener by
marshes than by meadows or cultivated fields. "Vast and impene¬
trable forests, unpassable marshes and thickets, frequent lakes,
swampy meadows, with cleared and dry spaces here and there occu¬
pied by villages, are the leading features of the region. Fishing
and hunting are the important sources of livelihood. The
characteristics of what may be described as the oak region, which
comprises all central Eussia, are totally different. The surface is
undulatory; marshy meadow lands no longer exist on the flat
watersheds, and only a few shelter themselves in the much deeper
and broader river valleys. Forests are still numerous where not
destroyed by man, but their character has changed. Conifers are
rare, and the Scotch pine, which covers the sandy plains, has
taken the place of Abies ; birch, oak, and other deciduous trees
1 Bibliography.—Memoirs of the Central Physical Observatory; Repertorium
fur Meteorologie and Meteorological Sbornik, published by the same body; Ves-
selovsky, Climate of Russia Wild, Temperatur-Verhdltni&se des Buss
B., 1881; Woyeikoff, The Climates of the Globe, 1884 (Russ.), containing the best
geneial information about the climate of Russia: Klossovsky, Thunderstorms in
Bussia, 1885 (Russ.); Memoirs and Izvestia oi the Geographical Society; many
papers in the Memoirs and Bulletin of the Academy of Sciences, in the Trudy
of the Scientific Societies at the Universities, in the Moscow Bulletin, <fcc.;
Woyeikoff and Leist in Appendix to Russian translation of Elise Reclus’s Ge'ogr.
Univ.; Woyeikoff, in Russkiy Kalendar and in Mem. Russ. Geogr.Soc., 1885.