Figure 9.1: The various spheres within the biosphere are connected.9.3 Biomes
Thebiosphere is divided up into a number ofbiomes. Biomes are regions with similar cli-
mate and geography. The key factors determining climate are average annual precipitation
(rainfall) and temperature. These factors, in turn, depend on the geography of the region,
such as the latitude and altitude of the region, and mountainous barriers. The specific con-
ditions of biomes determine the plant and animal life found within them. The communities
of plants, animals and soil organisms in a particular biome are collectively referred to as an
ecosystem. Biomes can beaquaticorterrestrial.Aquatic biomes DUMMY
Water covers a major portion of the Earth’s surface, so aquatic biomes contain a rich diversity
of plants and animals. Aquatic biomes are divided into two main groups depending on the
amount of salt present in the water: freshwater and marine biomes.- Freshwater
Freshwater biomes are defined by their low salt concentration (usually less than 1%). Exam-
ples include: ponds, lakes, streams, rivers and wetlands.- Marine biomes
Marine bodies are salty, having approximately 35 grams of dissolved salt per litre of water
(3,5%). Marine biomes are divided into oceans, coral reefs and estuaries. The vegetation of
the marine biome is made of of the different types of algae which is one the major source of
oxygen in the world. The green algae also also plays a role in the removal of carbon dioxide
from the atmosphere.- Oceans: are very large marine bodies that dominate the earth’s surface and hold the
largest ecosystems. The open ocean or sea covers nearly three-quarters of the earth’s
surface and contain a rich diversity of living organisms. Examples of animals in the
ocean biome include whales, sharks, octopuses, perlemoen, crabs and crayfish. Figure
9.2 shows a typical ocean ecosystem.
258 9.3. Biomes