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In fynbos-areas the water balance of mountain catchment areas have been upset by dense patches of alien plants, thus creating a far bigger fire hazard than the natural vegetation.

All seven of the most important biospheres are threatened by alien plants, with fynbos, savannah and wooded areas being affected most severely. Up to now efforts to kerb alien plants in the formal conservation areas of the sub-continent have met with varied success, when directed at alien trees and shrubs. Invasion by weeds and grasses are mostly ignored and little ecological information is available on this problem.

Activity 4:

To do research on alien species and put the findings into writing

[lo 1.2]

The eradication of alien species is a costly and time-consuming process.

1. Write short notes on one alien plant and one alien animal found in your area.

a) Alien plant

b) Alien animal

Some alien plants

Jointed cactus

Invasion by the jointed cactus hinder farming activities and cause the value of the land to depreciate. It diminishes the grazing potential of the veld.

Animals can become covered with sores and ulcerations as a result of the barbed thorns hooking into their flesh.


Parts of the plant are poisonous for humans, birds and other animals.

Early signs of poisoning include sweating, loss of appetite, nausea, vomiting, dizziness, stomach cramps, etc. Serious cases can lead to death due to heart failure or paralysis of the respiratory system.

Port Jackson

The Port Jackson was originally planted to bind the sand on the Cape Flats.

The bark of the trees was initially used for the tanning of leather, but was later replaced by better types of bark.

The wood of the Port Jackson is softer en weaker than that of Rooikrans, which is a better sand-binder.


This alien plant is so aggressive in the warmer regions of the Cape that it can choke trees of 10 metres in height.

Invasion in plantations hamper forestry activities. Animals eating the leaves may die.

Poisoning in humans may cause kidney failure, leading to death within three weeks.


Rooikrans forms thick, impenetrable stretches of large shrubs or low trees with entangled crowns.

They cause a serious problem, as the germination suppresses the growth of indigenous plants, causing them to disappear.


Learning Outcomes (LOs)

LO 1

Geographical Enquiry

The learner will be able to use enquiry skills to investigate geographical and environmental concepts and processes.

Assessment Standards(ASs)

We know this when the learner:

1.1 identifies and selects a variety of geographical and environmental sources relevant to an

enquiry [uses fieldwork and other enquiry methods; finds sources];

1.2 interprets maps and atlas information, graphical and statistical sources [works with sources].

LO 3

Exploring Issues (social and environmental)

The learner will be able to make informed decisions about social and environmental issues and problems.

We know this when the learner:

3.3 investigates possible ways of reducing resource consumption [makes choices].



  1. REDUCES : Carrying capacity refers to the number of sheep or stock that can graze successfully and sustainable on a hectare of land. Livestock must be reduced to be in line with the carrying capacity of the land. This will protect the land against overgrazing and prevent eventual soil erosion and desertification.

ENCOURAGED : Diversified (mixed) farming should be encouraged in areas with sufficient rainfall. This will prevent that farmers rely solely on one type of farming, and suffer financial losses when prices go down. It also helps to combat the exhaustion of the soil.

2. If these substances are used correctly (scientifically), it can help to increase production, which is to the advantage of the farmer and his land. Irresponsible and uncontrolled application of the said substances can result in the destruction of ecosystems and the poisoning of water resources, so that the land may become completely unproductive.

3. Urbanisation results in a rapid growth of the population in urban areas. This in turn causes a large demand for housing areas and commercial sites, the result of which is deforestation, or even the impingement on precious agricultural land, as urban areas expand towards the outskirts of towns and cities.


  1. Bottle corks: Synthetic corks are already being used on a wide scale

Rayon material: Natural fibres

Wooden planks: Hardened synthetic material – will be difficult

Wooden sawdust: Cottonwool and synthetic fibre or wool fibre

Paper: Impossible – recycling necessary

Sleepers: Concrete

Wooden boxes: Cardboard that can be recycled

Pencils: Plastic-covered graphite

Wetlands form a unique ecosystem and has to be protected.

Wetlands act as a “sponge” to absorb surplus water.

To maintain biodiversity.

Accommodates a large variety of plant and animal species.

Interest of the community.

2. Trees and woods play an essential role in the regulation of atmospheric and climatic processes.

It stores carbon and keeps local water cycles intact.

Stabilises soil (compact) against erosion.

Reduces the impact of floods.

Maintains species – ecosystem.

Tourism and recreation.


Answer will depend on area where you live.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Geography grade 8. OpenStax CNX. Sep 11, 2009 Download for free at http://cnx.org/content/col11036/1.1
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