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Natuurwetenskappe

Graad 8

Omgewing en interaksies

Module 33

Verskillende ekosisteme

Ons land is ryk aan wyduiteenlopende soorte ekosisteme.

Jou onderwyser sal julle waar moontlik na een of meer van hierdie ekosisteme neem.

Aktiwiteit 1:

Om die nut van ’n grasveld-ekosisteem te bespreek

[lu 1.3]

In groot dele van ons land vorm gras die grootste deel van die ekosisteme. Ons kan ook die term BIOOM gebruik om na die dele van ’n land wat min of meer dieselfde ekologiese kenmerke toon, te verwys. So kry ons byvoorbeeld ’n grasveldbioom. ’n Grasveldbioom kan as ’n groot ekosisteem beskryf word of dit kan in kleiner grasveld-ekosisteme verdeel word.

Kennis van die grasveldbioom en -ekosisteme is belangrik in Suid-Afrika, aangesien groot dele van die land vir veebeweiding benut word.

Wildsboksoorte soos impala, buffels en springbokke is ook grasvreters.

Die tipe gras in ’n ekosisteem word hoofsaaklik deur die aard van die grond bepaal.

Grasveldbiome word in terme van die dominante grassoort wat daarin voorkom, benoem.

Die hooftipes grasveld-ekosisteme (eintlik biome) is:

1. soetveld – lae reënvalgebiede; goeie voer vir vee;

2. suurveld – hoë reënvalareas; nie baie goeie weiding nie;

3. gemengde veld.

Rooigras Themeda triandra is ’n welbekende grassoort wat baie voedsaam is vir vee.

Oorbeweiding is die boer se grootste oortreding, want dit lei op sy beurt tot erosie, woestynvorming en gevolglik hongersnood.

Voer ’n klasdebat oor die volgende vraag:

  • Is die gereelde brand van gras goed of sleg vir die omgewing?
  • Dui die voor- en nadele soos wat dit uit die debat voortspruit in die kolom hieronder aan.
VOORDELE VAN BRAND NADELE VAN BRAND
.............................................................. ..............................................................
.............................................................. ..............................................................
.............................................................. ..............................................................
.............................................................. ..............................................................
.............................................................. ..............................................................
.............................................................. ..............................................................
.............................................................. ..............................................................

Assessering van DEBAT:

Het jy ’n waardevolle bydrae tot debat gelewer?

[LU 1.3]

Aktiwiteit 2:

Om ’n woud/boomekosisteem te bespreek

[lu 1.2; 1.3; 2.4]

Bome is nie net produseerders nie, maar vorm as gevolg van hul grootte ook die habitat van verskeie spesies.

Dier- en plantspesies bewoon bome.

Die blaarbedekking van bome verskaf skuiling vir voëls. Die bas en skeure in die boom verskaf ’n habitat vir ’n menigte insekspesies. Die blaarbedekking vorm ook ’n skaduryke omgewing vir skaduliewende, laaggroeiende plante.

Die blomme en vrugte wat bome in sommige gevalle voortbring, is ’n kosbron vir baie.

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
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Source:  OpenStax, Natuurwetenskappe graad 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11049/1.1
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