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3.18 Environment and Ecology
Te main species of animals include reindeer, caribou, white-bear, polar fox, arctic fox, musk-ox,
stoat, wolves, rodents, lemmings, shrew, etc. Most of the animals of tundra biome have thick and dense
insulating coat of fur or feathers around their bodies. In tundra biome, polar bears are well-adapted to
swimming with a water-repellent coat and webbed feet. Te fur keep the animals warm during severe
winters. Te birds such as water fowl, ducks, swan, geese, etc. migrate seasonally. Mosquitoes, midges
and blacky are the important species of insects which emerge in huge swarms in pools, lakes, swamps
during summer.
Alpine Tundra Biome
Alpine tundra is similar to arctic tundra, but can occur at lower latitudes because it is associated with high
elevation. Tis biome is usually described ‘as above the timberline’, which means that elevation above which
trees cannot grow. Timberline increases in elevation equator-ward in both the hemispheres. Alpine tundra
communities occur in the Andes near the equator, the Himalayas, White Mountains of California, the
Rockies, the Alps, and Mt. Kilimanjaro of equatorial Africa, as well as mountains from the Middle East to
Asia. Alpine meadows (Margs) feature grasses and stunted shrubs, such as willow and heath (Fig. 3.11).
Te height and size of canopy of diferent trees varies from biome to biome and region to region. A
comparative picture of the height, size of some of the important trees of the world has been given in
Fig. 3.12.
It may be observed from Fig. 3.12 that the giant red-wood (douglas-fr) with a height of 90 to 100
metres is the tallest tree of the world, followed by the Brazil-nut (60 metres) and Elm of North-West
Europe (50 metres), and willow about 45 metres. Te relative heights of banana, elephant-grass and
other grasses have also been given in this fgure.
Table 3.1 Major Biomes and their Salient Characteristics
S. No. Biome Vegetation Annual Temperature Water Balance
Characteristics Precipitation Pattern
1. Tropical Rain Leaf canopy thick and 180-400 21-30oC average Surplus all the
Forests continuous; broad- 25oC year
leaf, evergreen trees (>6cm,in each
(lianas), epiphytes, tree month)
ferns, palm. About
40% of world’s plants
and animals are found.
2. Tropical Transitional between 130–200 cm, Variable and Seasonal surplus
Deciduous rainforest and (40 rainy days always warm and defcits
or Monsoon tropical-grasslands; during four driest (>18oC)
Biome broadleaf, deciduous months)
trees; open parkland
to dense undergrowth
(Contd.)
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Major Biomes 3.19
Table 3.1 (Contd.)
S. No. Biome Vegetation Annual Temperature Water Balance
Characteristics Precipitation Pattern
3. Savannah Transitional between 90–150 cm, No cold weather Tend to moisture
Biome deciduous rain- limitations defcit, therefore
forests, and semi-arid seasonal fre and drought
tropical steppes and susceptible
deserts; trees with
fat crowns, great
diversity of grazers,
antelopes, bufaloes,
zebras, elephants,
rhinoceros, lions,
cheetah, hyena, mon-
goose and rodents.
4. Subtropical Mixed broadleaf and 75–150 cm Temperate, with Seasonal pattern
mixed Ev- needle-leaf trees; cold season with summer
ergreen and deciduous broad- and maximum
Deciduous leaf, losing leaves in precipitation
Biome winter, southern and
eastern evergreen
pines demonstrate
fre association
5. Temperate Narrow margin of 150–500 Mild summer Large surplus and
Rainforest lush evergreen and and mild winter run-of
deciduous trees on
windward slopes:
red-wood, douglus-
fr (tallest trees of the
world-height about
100 meters)
6. Mediterranean- Short shrubs, 25–65 (summer Hot, dry sum- Summer defcit,
Biome drought adapted, season dry) mer, cool winter winter surplus
tending to grassy
woodlands; chapar-
ral, maquis, etc
7. Mid-latitude Broad leaf forest 75–150 cm More rains in Adequate in all
Deciduous maple, etc. Beach, winter months
Biome oak, maple, mul-
berry, willow, and
cherry. Most animals
are vertebrates and
invertebrates
(Contd.)
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3.20 Environment and Ecology
Table 3.1 (Contd.)
S. No. Biome Vegetation Annual Temperature Water Balance
Characteristics Precipitation Pattern
8. Temperate Highly modifed 25–75 cm Temperate con- Soil moisture
Grasslands by human activity; tinental climate utilisation and re-
major areas of com- charge balanced;
mercial grain farm- irrigation and dry
ing. Bison, antelope, farming in drier
rodents, dog, wolves areas
and ground-resting
birds.
9. Taiga Biome Coniferous, needle- 25–60 cm Continental Water surplus
leaf Biome spruce, climate, high throughout the
fr and pine are the annual range of year
main trees, small seed temperature
eating birds, hawks,
fur bearing-carni-
vores, little mink,
elks, puma, siberian
tiger, fox and wolves
are the main wild
animals.
10-A Hot deserts and Bare ground, gradu- <20 cm Average annual Chronic defcit,
semi-deserts ating into xerophytic temperature irregular pre-
plains including around 18oC cipitation; more
succulents, cacti, evaporation than
saquaro, sagebrush precipitation
and dry shrubs,
reptiles, mammals
and birds
10-B Cold desert and Short grass, and dry 10–20 cm Average annual More evaporation
semi-desert shrubs temperature less than precipitation
than 18oC
11. Arctic and Treeless, dwarf 25cm Warmest month Not applicable
Alpine Tundra shrubs, stunted 10oC, only 2 or most of the year,
sedges, mosses, lichen 3 months are poor drainage in
and short grasses, above freezing summer
alpine pastures, grass- temperature
meadows (Margs)
snowy owl, lemming,
arctic hare, white fox,
white bear. Reptiles
and amphibians are
almost absent.
Source: Christopherson, R.W., 1995, Elemental Geo-systems: A Foundation in Physical Geography, New Jersey,
Prentice Hall, pp.508–9.
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Major Biomes 3.21
Giant-redwood
Brazil-nut
Elm
Poplar
Spruce Willow
Baobab
Howthorne
Flowering
Lilac
Fig dogwood
Joshua tree
Juniper
Banana
Elephant grass
Fern Cattail
Grasses
Fig. 3.12 Forms of Plants (after W. M. Marsh and J. Dozier, Landscape:
An Introduction to Physical Geography, 1981, p.273)
