Climate and Natural Vegetation

Study and revision resources

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1. Physical Factors affecting Ecosystem and Biome Distribution

Ecosystem: A community of interdependent organisms and the physical environment they inhabit.

Biome: A collection of ecosystems sharing similar climatic conditions; for example, tundra, tropical rainforest, desert.

Solar Radiation Received

The concentration of the suns energy reaching the earth diminishes with distance from the equator. As the diagram shows, the curvature of the earth results in the solar radiation being spread over a much wider surface area.

The result of this is much warmer temperatures around the equator which results in high levels of evaporation from the oceans.

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Figure 6.1 Solar Radiation Received

Atmospheric Circulation

  • Equatorial low: low pressure surrounding the equator. Rising warm moist air leads to high levels of precipitation, tropical rainforest.
  • Sub-tropical high: high pressure areas around the tropics of Cancer & Capricorn. Descending warm dry air results in arid/desert regions.
  • These air cells redsitribute heat around the globe through moving warmer air from the equator north & south, and colder air from the poles towards the equator.
Atmospheric air cells
Figure 6.2 Atmospheric Cells

2. Photosynthesis & the Food Chain

Photosynthesis

Ecosystems and all the life that exists within them rely on the ability of plants to harness the suns energy and convert it into gulcose.

The energy is then transfered through the food chain and eventually recycled as animals and plants die, decompose and return the nutrients to the soil.

  • Producers these are the plants that produce the initial usable energy.
  • Consumers eat the producers & maybe other consumers.
  • Decomposers return the nutrients to the soils.

Photosynthesis also plays an important role in producing oxygen which is essential for life.

  1. Draw and label a diagram showing the process of photosynthesis.
  2. Energy is lost in each stage of the food, describe ways in which this happens.
Photosynthesis diagram
Figure 6.3 Atmospheric Cells

The Food Chain

Ecosystems and all the life that exists within them rely on the ability of plants to harness the suns energy and convert it into gulcose.

The energy is then transfered through the food chain and eventually recycled as animals and plants die, decompose and return the nutrients to the soil.

  • Producers these are the plants that produce the initial usable energy.
  • Consumers eat the producers & maybe other consumers.
  • Decomposers return the nutrients to the soils.

Photosynthesis also plays an important role in producing oxygen which is essential for life.

  1. Draw and label a diagram showing the process of photosynthesis.
  2. Energy is lost in each stage of the food, describe ways in which this happens.
Food chains
Figure 6.4 Food Chains

3. Tropical Rainforest

Rainforest Canopy
Figure 6.5 Rainforest canopy
Epiphytes and air plants
Figure 6.6 Epiphytes and Bromeliads
Lianas and vines
Figure 6.7 Lianas and vines
butress roots
Figure 6.8 Rainforest butress roots
Rainforest Shrub Layer
Figure 6.9 Rainforest shrub layer

Rainforests ecosystems have a distinct structure. You should be able to describe the structure and link it to the adaptations of plants in this ecosystem.

Rainforest Structure
Figure 6.10 Rainforest structure

Amazon Rainforest

Tasks

  1. Draw a large version of Figure 6.10.
  2. Add labels pointing to the correct layers that describe the ways in which plants have adapted to the conditions there.
  3. Use figure 6.11 to describe the location of Manaus.
  4. Use the data in table 6.1 to draw a climate graph for Manaus. Make sure the graph is labelled correctly.
  5. Explain the varaiation in the climate throughout the year in Manaus climate.
Month Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec
Temp0C 28 29 28 28 29 29 30 31 31 30 29 30
Rainfall 380 310 315 240 230 110 110 100 110 100 250 300
Table 6.1: Manaus Climate Data
Figure 6.11: Manaus Locational Map

Rainforest Destruction

Deforestation is a major issue in many areas of the world, not just rainforests. The global importance of rainforests in climate stability and species biodiversity gives them added importance.

Open this link WWF Deforestation and use the sections (tabs at the top) to answer the following questions.

Introduction

  1. Give 3 reasons why rainforests are important.
  2. What % of the Amazons rainforest has been lost in the last 50 years?
  3. The Amazon has many valuable natural resources that people wish to exploit, state the 3 mentioned.

Causes

  1. Describe and explain the 4 main causes of deforestation in rainforests (dont just bullet point the cause, you need to be able to say why its happening).

Impacts

  1. What % of the worlds biodiversity lives in rainforests?
  2. Describe the ways in which deforestation leads to increased greenhouse gas emissions.
Video 6.1: Amazon Rainforest Deforestation
rainforest clearance
Figure 6.12: Rainforest Clearance for Cattle

4. Hot Desert

Climate and Vegetation/Animal Adaptations

Hot desert ecosystems are found in the sub-tropical high pressure regions (see figure 6.3) north and south of the the equator.

High pressure and relatively close proximity to the equator result in clear skies and high levels of solar radiation recieved. The clear skies result in very low rainfall totals aswell as hot daytime temperatures but cold nights as the heat escapes easily.

Vegetation Adaptations:

Figure 6.13: wide circular stem allows cacti to store lots of water after rains. Waxy skin reduces water loss through evaporation. Sharp spines protect the cacti from being eaten by animals.

Figure 6.14: the ridges running down the stem allow the cactus to swell considerably to store extra water wehn it is available.

Cacti often have either long shallow roots that spread out to absorb any rainfall or they have long deep taproots to reach groundwater.

Animal adaptations:

Figure 6.15: Camels have wide feet to spread their weight on the sand, long eyelashed to protect agaist wind blown dust and sand, humps to store extra water and long legs to raise their bodies away from the surface where the temperature is highest.

Snakes and insects burrow into the sand during the day to avoid the heat.

camel
Figure 6.15: Camels walking in Egypt

Tasks

  1. Use table 6.2 to draw a correctly labled desert climate graph.
  2. Describe and explain the variations through the year.
Month Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Temp0C

 19 21 24 28 32 35 35 35 33 30 26 21
Rainfall (mm) 7 4 4 2 0 0 0 0 0 1 3 5
Table 6.2: Cairo Climate Data
cacti
Figure 6.13: Prickly Pear Cactus
cacti adaptations
Figure 6.14: Cactus Adaptations

Opporutnities and Threats in Deserts

Tasks

Use Videos 6.2 and 6.3 and to help answer the following:

  1. Why are deserts being increasingly used for solar farms? (give at least 3 different reasons).
  2. How many home is the Ivanpah solar plant expected to supply energy for?
  3. How can solar plants store energy for use through the night?
  4. Describe briefly the environmental concerns that the company faced when building the solar plant.
  5. Describe why the desert ecosystem is under threat in Israel.
  6. Where does the water come from to irrigate the crops in the desert?
  7. Why is precision drip irrigation technology so important to this type of farming?
  8. Suggest ways that mining in the desert (Video 6.4) damages the ecosystem.
Video 6.2: Desert Solar Farms
Video 6.3: Greening the Desert, Israel
Video 6.4: Mining in Australian Desert

5. Revision

Content for Accordion Panel 5

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