3. What is climate ?
Weather conditions dominating an area in general or
over a long period.
Climate is also a measure of the average pattern of the
variation in temperature, humidity, pressure , wind,
Climate is different from weather, weather only
describes the short term conditions of these variables in
a given region.
E.g cold, hot, windy, rainy, etc .
4. What are biomes ?
A large naturally occurring community of flora and founa occupying a major
habit, e.g. forest of tundra.
5. Climate effect on biomes
What do temperature, wind and rain have
They are all part of climate, the statistical
of temperature, humidity, atmospheric
pressure, wind, rainfall, other
meteorological measurements in a given
region over long periods. In other words, is it
dry or wet, hot or cold, or humid? And it is
these abiotic factors that help determine the
nature of a biome.
6. Plants and temperature
Plants and Temperature. Tropical plants are most competitive in the
tropical zone and warmer parts of the subtropical zones. These plants
generally cannot survive winters, and so are restricted to their
homelands. Subtropical plants can tolerate some very light frost, but
cannot tolerate any kind of "hard" frost. They survive in the
subtropical zones, and in some areas in the tropical zone. Plants that
can survive hard frosts or freezes are called Hardy Plants. These
plants can handle varying levels and durations of freezing, explaining
their distributions up into the high latitudes toward the Polar Circles.
Where permafrost exists the thin layer of soil that thaws briefly in
summer supports the distinct vegetation known as tundra. These are
among the toughest plants on earth. They go through their life cycle in
just a few weeks of summer and then tolerate extreme cold for the
rest of the year. They tend to be short in stature.
Forest is the smallest biome in South Africa,
covering only about 0.1% of the country (1 062
Forests are found from sea level to above 2000
metres. They grow in areas with high rainfall and
no frost. Forests are moist and seldom burn.
Forests consist of trees that form a
closed canopy, with layers of plants beneath the
The largest and most famous forests in South
Africa are the Knysna and Tsitsikamma Forests of
the southern Cape.
South African fynbos grows in a
100km- to 200km-wide coastal
belt stretching from the West
Coast to the south-east coast. It
makes up 80% of the Cape Floral
Region, a world of finely
branched plants beautifully
adapted to flourish in poor soils
and wildly varying rainfall
Grassland biomes are large, rolling terrains
of grasses, flowers and herbs. Latitude, soil
and local climates for the most part
determine what kinds of plants grow in a
particular grassland. A grassland is a
region where the average annual
precipitation is great enough to support
grasses, and in some areas a few trees. The
precipitation is so unpredictable that
drought and fire prevent large forests from
growing. Grasses can survive fires because
they grow from the bottom instead of the
top. Their stems can grow again after being
burned off. The soil of most grasslands is
also too thin and dry for trees to survive.
The Nama Karoo Biome occurs on
the central plateau of the western
half of South Africa, at altitudes
between 500 and 2000m, with most
of the biome failing between 1000
and 1400m. It is the second-largest
biome in the region.
Savannas have warm temperature
year round. There are actually two
very different seasons in a savanna; a
very long dry season (winter), and a
very wet season (summer). In the dry
season only an average of about 4
inches of rain falls. Between
December and February no rain will
fall at all. Oddly enough, it is actually
a little cooler during this dry season.
But don't expect sweater weather; it
is still around 70° F.
14. Succulent karoo
The Succulent Karoo, including desert, covers
about 7.5% of the country (approximately 83
This biome covers the arid western parts of
South Africa, including Namaqualand and the
The region is extremely dry in summer and
the temperature often rises above 40oC. Rain
falls in winter and varies from 20 to 290 mm
16. Terrestrial biomes and climate
Climate is the average weather in an area over a long period of
time. Weather refers to the conditions of the atmosphere from day to day.
Climate is generally described in terms of temperature and moisture.
Temperature falls from the equator to the poles. Therefore, major
temperature zones are based on latitude . They include tropical, temperate,
and arctic zones, However, other factors besides latitude may also influence
temperature. For example, land near the ocean may have cooler summers
and warmer winters than land farther inland. This is because water gains and
loses heat more slowly than does land, and the water temperature influences
the temperature on the coast. Temperature also falls from lower to higher
altitudes. That’s why tropical zone mountain tops may be capped with snow.
18. Terrestrial biomes
In terms of moisture, climates can be classified as arid (dry), semi-arid, humid (wet), or semi-
humid. The amount of moisture depends on both precipitation and evaporation. Precipitation
increases moisture. Evaporation decreases moisture.
The global pattern of precipitation is influenced by movements of air masses. For example, there is
a global belt of dry air masses and low precipitation at about 30° N and 30° S latitude.
Precipitation is also influenced by temperature. Warm air can hold more moisture than cold air, so
tropical areas receive more rainfall than other parts of the world.
Nearness to the ocean and mountain ranges may also influence the amount ofprecipitation an area
receives. This is explained in Figure below .
Evaporation of moisture is greatest where it is hot and sunny. Therefore, cold climates with low
precipitation may not be as dry as warm climates with the same amount of precipitation.
Moist air from the ocean rises up over the mountain range.
As the air rises, it cools and its water vapor condenses. Precipitation falls on the windward side of
the mountain range.
The air is dry when it reaches the leeward side of the mountain range, so there is little precipitation
there. This creates a “rain shadow.”
19. Climate and plant growth
Plants are the major producers in terrestrial biomes. They have five basic
needs: air, warmth, sunlight, water, and nutrients. How well these needs are
met in a given location depends on the growing season and soil quality, both
of which are determined mainly by climate.
The growing season is the period of time each year when it is warm and wet
enough for plants to grow. The growing season may last all year in a hot, wet
climate but just a few months in a cooler or drier climate.
Plants grow best in soil that contains plenty of nutrients and organic matter.
Both are added to soil when plant litter and dead organisms decompose.
Decomposition occurs too slowly in cold climates and too quickly in hot, wet
climates for nutrients and organic matter to accumulate. Temperate
climates usually have the best soil for plant growth.
20. Climate and biodiversity
Because climate determines plant growth, it also influences the number and
variety of other organisms in a terrestrial biome. Biodiversity generally
increases from the poles to the equator. It is also usually greater in more
humid climates. This is apparent from the desert and rainforest biomes.