BIOSPHERE AND BIOMES 20 AUGUST 2014

Lesson Description

In this lesson we:

Discuss the following:

o The concept of the biosphere o The interconnectedness with and components of the global ecosystem: lithosphere,

atmosphere and hydrosphere o The terrestrial and aquatic biomes of Southern Africa

Summary

The Biosphere

The part of the planet that supports life e.g. atmosphere(air), lithosphere (land) and

hydrosphere(water)

The atmosphere is the body of air which surrounds our

planet. Most of our atmosphere is located close to the

earth's surface where it is most dense. The air of our planet

is 79% nitrogen and just under 21% oxygen; the small

amount remaining is composed of carbon dioxide and other

gasses.

The hydrosphere is composed of all of the water on or near the earth.

This includes the oceans, rivers, lakes, and even the moisture in the air.

Ninety-seven percent of the earth's water is in the oceans. The

remaining three percent is fresh water; three-quarters of the fresh

water is solid and exists in ice sheets

Aquatic organisms depend on the hydrosphere for life

The lithosphere is the solid, rocky crust covering entire planet. This

crust is inorganic and is composed of minerals. It covers the entire

surface of the earth.

This is where terrestrial organisms live

Interconnections of the Spheres

The lithosphere, hydrosphere and atmosphere form the biosphere.

The soil, water and air support life on earth.

Life on earth is linked in each of the three spheres.

All four spheres can be and often are present in a single location. For example, a piece of soil

will of course have mineral material from the lithosphere. Additionally, there will be elements

of the hydrosphere present as moisture within the soil, the biosphere as insects and plants,

and even the atmosphere as pockets of air between soil pieces.

There are two components to the biosphere

o A biotic or living component – animals, plants microorganisms etc.

o An abiotic or non-living component – water air temperature, soil etc.

o The biotic and abiotic factors of the biosphere form the global ecosystem

Living organisms are not evenly distributed throughout the biosphere.

Scientists have divided the earth into regions according to their climate, soil, plants and

animals that live their – these

regions are called biomes

Biomes are sub-divided into

ecosystems.

Ecosystems are communities

of organisms that interact in a

particular environment.

An organism lives in a certain

place where it gets its food,

space and where it reproduces

– this is called its habitat

Scientists divide biomes into :

o Terrestrial biomes that

occur on land –

grasslands, savannah,

fynbos

o Aquatic biomes - marine, wetlands, coastal

South African Biomes – Terrestrial

Biomes Characteristics Savannah

• Savannas are the wooded grasslands of the tropics and subtropics that account for 46% of the South African landscape.

• Stretches from the Kalahari in the west into the north and north-east of Limpopo

• Rainfall2oo-1000mm • Summers hot and wet • Winter cool and dry • Soil fertile • Vegetation: Grasses, thorn tress, large shrubs,

trees (marula, baobab) • Animals:‘Big 5” blue wildebeest, eland, hippo,

kudu, cheetah, zebra, giraffe, wild dogs

Grassland

• The grasslands cover the high central plateau of South Africa, inland areas of Kwazulu-Natal and the mountain areas of the Eastern Cape Province

• Variety – rainfall varies, thunderstorms and hailstorms

• Winters cold with or without frost, fires common

• Summer – hot and wet • Soil type- fertile • Plants - Grasses (rooigras) • Animals - Blesbok, black wildebeest, springbok

Nama-Karoo

• The Nama-Karoo covers most of the vast central plateau region of the Western and Northern Cape Provinces.

• Semi-desert – flat and rugged • Ground dry and rocky • No permanently flowing rivers (no rain) • Rainfall less than 500mm • Summer high temp • Winter freezing cold • Soil – rich in lime, thin layer of soil over rock,

infertile • Plants – xerophytes, low bushes, grass and

shrubs - Stone plant, sweet thorn, Karoo daisy • Animals - black-eared jackal, leopard, baboon,

vervet monkey, tawny eagle

Succulent Karoo

• This biome occurs mostly west of the western escarpment through the western belt of the Western Cape and inland towards the Little Karoo.

• The succulent Karoo is restricted to the year-round and winter rainfall areas and have the greatest summer aridity

• Rainfall - dry, 50mm-350mm rainfall • Summers – hot and dry • Soil – rich in lime, infertile and erodes easily • Plants – xerophytic, Namaqualand daisies,

succulents, lichens • Animals – small rodents- mice squirrels, Bat-

eared fox, suricate, barking gecko

Fynbos

• Fynbos occupies 5,3 % of South Africa, occurring almost exclusively in the south-western and southern parts of the Western Cape Province.

• Winters cold and wet – 210-3000mm • Summers hot and dry • Soil – infertile soil that is leached of all its

nutrients – inhibits growth of larger plants • 68% of plants endemic to the fynbos biome • One of the six floral kingdoms in the world • Fires common in summer – needed to stimulate

germination • Plants- Proteas, shrubs and trees, rooibos tea,

buchu, olives, table wine, thatching reed • Animals - Klipspringer, Cape mountain zebra,

leopard, geometric tortoise, baboons, porcupines, lynxes , Cape sugar bird

South African Biomes – Aquatic

Marine and Coastal Biomes

Include – oceans, coral reefs and estuaries

Biomes include salty water.

Algae live in the water and produce oxygen and food

South African marine biome contains 12% of the worlds fish species. Our coastline is 3000km long

Water on the east coast is warm because of the warm Indian current and the water on the west coast is cold because of the Benguela current.

The west coast water are rich in nutrients which provides food for plankton and fish

Organisms

Plankton- phytoplankton (algae), zooplankton (microscopic crustaceans) – fish and large fish – sharks, dolphins, whales – animals living on the bottom – crabs, oysters, sponges, lobster etc.

Concentration of nutrients

Coral Reefs

Shallow waters off the northern coast of Kwa-Zulu Natal

Coral reefs are formed from calcium carbonate of tiny corral animals

Large biodiversity

Animals – micro-organisms, invertebrates, fish, sea urchins, sea-stars, octopusi

Open Sea Zone

Open ocean

Temperature is generally cold

Plankton main food provider for fish, dolphins and whales

Forests

• Smallest biome. Mountainous forests along the Southern Cape coastline – Knysna and Tsitsikamma

• Rainfall – throughout year, mainly winter • Forests cool and moist, humid • Soil deep and fertile • Plants - Outeniqua Yellowwood, epiphytes,

herbaceous and bulbous plants • Animals - Blue duiker, bush-pig, Knysna Lourie

and woodpecker , paradise flycatcher

Thickets

• Along the coast of Kwa-Zulu Natal and Eastern Cape

• Rainfall fairly high but not sustainable for forests

• Soil – shallow and varies from sandy loam to sandy clay that is rich in lime

• Plants – varies, shrubland to low forests, evergreen and succulent trees and shrubs, plants have thorns. Short trees, spekboom, Cape honeysuckle, Plumbago

• Animals - Elephants, antelopes, monkeys, squirrels, bushbuck , African python

Wetlands

Area of land which is covered predominately by shallow water.

Include mountain springs, marshlands, flood plains, estuaries to swamp forests that are linked by river and streams.

Rich in biodiversity- o Birds o Large amount of carbon o These wetlands share common and

important functions in river catchments by providing a regular water supply, by filtering the water naturally

o By reducing the effects of floods and droughts.

Estuaries

Are areas where freshwater of streams or rivers meet with the salt water of the sea

Water conditions, temperature and salt content, change constantly with the tides

Rich in nutrients

Plants – algae, seaweed, marsh grass and mangroves

Animal – prawns, sponges, mussels, barnacles, crabs

Test Yourself

Question 1

In the ecosystem of a tropical rainforest, the producers obtain energy from the:

A consumers

B decomposers

C rotting leaves

D sunlight.

Question 2

Which set of words correctly shows the organisation of living things from the largest to the smallest?

A species → biosphere → community

B biosphere → community → species

C individual → biosphere → community

D species → individual → community

Question 3

The boundaries between biomes are usually seen as

A. gradual transition zones

B. abrupt changes in vegetation, but not of animals

C. abrupt changes in both vegetation and animals

D. distinct geographic barriers such as mountains and rivers

E. abrupt changes in animals, but not of vegetation

Question 4

Organisms that use inorganic nutrients and an outside energy source to produce sugars and other organic nutrients for themselves and other members of the community are

A. autotrophs

B. producers

C. heterotrophs

D. herbivores

E. both a and b

Question 5

Light is regarded as an abiotic factor because it is

A. necessary for life.

B. not continuous.

C. non-living.

D. contains energy.

E. radiant.

Question 6

A population is made up of

A. Individuals

B. Communities

C. Ecosystems

D. Different species

Improve your Skills

Question 1

Study the map below where South Africa’s terrestrial biomes are indicated with the letters A to G and answer the questions that follow

1.1 Define the term biome 1.2 Name the TWO main types of biomes 1.3 Identify the biomes A-G. 1.4 Which biome is a main tourist attraction during spring, when the whole area is covered with

flowers? 1.5 Which biome includes one of the world’s richest floral kingdoms? 1.6 Which biome attracts tourists to its many game farms? 1.7 Which biome is the largest? 1.8 Which biome will you find the following plant species?

a) Vygies, quiver trees

b) Yellowwood and stinkwood

c) Mopani and baobab

d) Proteas, ericas and reeds

G

Question 2

The gemsbok is a large herbivore that lives in herds in desert areas of South Africa. Gemsbok feed on plants that are adapted to living in dry conditions. There are not many rivers, lakes or ponds that provide drinking water for the animals. The desert areas are hot during the day but cool at night. As the air cools at night it becomes moist, and the plants absorb the moisture. 2.1 A few lions live in the desert areas. They hunt and

feed on the gemsboks. Use the information from the drawing of the gemsbok to suggest two ways in which it could avoid being killed by lions.

The graphs show the water content of the grass and the times of day that the gemsbok feed.

2.2 Describe how the water content of the grass changes during the day. (4) 2.2 Suggest why the water content of the grass changes. (2) 2.3 Between which times of the day are more than 25% of the herd feeding? (2) 2.4 Suggest an advantage to the gemsbok of feeding mainly at these times. (2)

Question 3

Use the map below to help answer the questions that follow:

3.1 Name the two types of forest found in South Africa. Describe the soil and climatic conditions

of these biomes. 3.2 What influence could the cold Benguela current on the west coast of South Africa have on

the vegetation? 3.3 In what way is the fynbos region not suitable to the growth of plants? 3.4 Why is fire important for the fynbos vegetation? 3.5 What is the difference between the vegetation of the grasslands and savannah? 3.6 Describe the effect elephants will have on the savannah during times of drought. 3.7 How are plants adapted to survive the harsh Karoo regions? 3.8 How are animals adapted to withstand the extreme high temperature conditions in the

Karoo? 3.9 What is the importance of fog from the Atlantic ocean in the succulent karoo

Links

Clear Diagram and Summary:

http://cnx.org/contents/fe5ee9f2-7357-4d82-8fc3-44da2ac322e8@1