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Key concepts

In this session we will focus on summarising what you need to know about:

  • Terrestrial and aquatic biomes of Southern Africa.
  • How climate, soil and vegetation influence the organisms found in each.
  • Location of the different biomes in South Africa.


Biomes can be defined as the major climatic regions of the world, classified according to their predominant vegetation and characterised by adaptations of organismsto that particular environment.


The biosphere can be divided into relatively large regions called biomes. A biome has a distinct climate and certain living organisms (especiallyvegetation) characteristic to the region and may contain many ecosystems. The key factors determining climate are average annual precipitation andtemperature. These factors, in turn, depend on the geography of the region, such as the latitude and altitude of the region, and mountainous barriers. Themajor types of biomes include: aquatic , desert , forest , grassland and tundra . Biomes have no distinct boundaries. Instead, there is a transition zone called an ecotone, which contains a variety of plants and animals. For example, anecotone might be a transition region between a grassland and a desert, with species from both.

You will be required to learn about terrestrial and aquatic biomes.

Aquatic biomes

Water covers a major portion of the earth's surface, so aquatic biomes contain a rich diversity of plants and animals. Aquatic biomes can be subdivided into two basic types: freshwater and marine .

A freshwater region has a low salt concentration, usually less than 1 percent, and occurs in several types of regions: ponds and lakes, streams and rivers, and wetlands.

  • Ponds and lakes range in size, and small ponds may be seasonal. They sometimes have limited species diversity due to isolation from other water environments. They can gettheir water from precipitation, surface runoff, rivers, and springs.
  • Streams and rivers are bodies of flowing water moving in one general direction (i.e., towards the sea). Streams and rivers start at their upstream headwaters, which could besprings, snowmelt or even lakes. They continue downstream to their mouths, which may be another stream, river, lake or ocean. The environment of a streamor river may change along its length, ranging from clear, cool water near the head, to warm, sediment-rich water near the mouth. The greatest diversity ofliving organisms usually occurs in the middle region.
  • Wetlands are places of still water that support aquatic plants, such as cattails, pond lilies and cypress trees. Types of wetlands include marshes, swamps and bogs. Wetlands have the highest diversity of species with many species of birds, mammals, amphibians and reptiles. Some wetlands, such as salt marshes, are notfreshwater regions.

Marine regions cover nearly three-fourths of the earth's surface. Marine bodies are salty, having approximately 35 grams of dissolved salt per litre of water (3.5percent). Oceans are very large marine bodies that dominate the earth's surface and hold the largest ecosystems. They contain a rich diversity of living organisms. Oceanregions can be separated into four major zones: intertidal, pelagic, benthic and abyssal .

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
why and for what was five kingdom of classification of organisms introduced
give the ans as fast as possible
Comment on the ozone depletion over the period of 1982 to 1996
Mpho Reply

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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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