The Living World: Tropical Rainforests Flashcards Preview

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Flashcards in The Living World: Tropical Rainforests Deck (46):
1

Characteristics of biomes: TROPICAL RAINFOREST

-Found near the equator

-Hot and humid (equatorial) with heavy rainfall

-Covers 6% of the earth's land surface

-Contains around half of all the world's species

-A quarter of all medicines come from rainforest plants

2

Layers of the tropical forest: SHRUB LAYER

-Near forest floor and extremely dense
-Dark and gloomy with little vegetation between the trees
-Can flood during heavy rainfalls

3

Layers of the tropical forest: UNDER CANOPY

-Limited sunlight
-Saplings wait here for larger plants and trees to die and leave a gap in the canopy which they can grow into
-Lianas can climb up trees to get sunlight

4

Layers of the tropical forest: CANOPY

-Where upper parts of most trees are found
-Typically 20-40 metres tall
-Home to about 50% of rainforest (insects, birds, some mammals)

5

Layers of the tropical forest: EMERGENTS

-Tops of tallest trees in rainforest
-Much higher, so able to get more light then average trees in canopy
-Layer can grow in excess of 50 metres

6

Environmental characteristics of tropical rainforests
-CLIMATE

-Thrive in warm and wet conditions
-Equatorial zone characterised by high rainfall and temp throughout the year*
*(Climate generally stays same with only some dryer and wetter months)

7

Environmental characteristics of tropical rainforests
-PLANTS AND ANIMALS

-Provides habitats for over half all plant and animal species on the planet
-Birds live in the canopy feeding on nectar from flowers
-Mammals (monkeys, sloths) are well adapted to living in trees
-Animals (deer, rodents) live on forest floor

8

Environmental characteristics of tropical rainforests
-SOILS

-Mostly infertile
-Most nutrients found at surface, where dead leaves decompose rapidly in the hot and humid conditions
-Many trees and plants have shallow roots to absorb these nutrients
-Fungi growing on roots transfer nutrients straight from air (nutrient cycling)
-Heavy rainfall can quickly dissolve and carry away nutrients (leaching)
-This leaves behind an infertile, red, iron-rich soil (latsol)
-

9

Environmental characteristics of tropical rainforests
-PLANT AND ANIMAL ADAPTATIONS

-Majority of plant and animal species found in canopy, where there is the most light
-Biotic factors have a close relationship with abiotic factors: small changes to either factors (e.g. deforestation, water pollution) can have serious knock-on effects on the entire ecosystem

10

ADAPTATION: Lianas

Woody creepers rooted to the ground but carried by trees into the canopy where there is more sunlight

11

ADAPTATION: Buttress roots

Massive ridges to help support bases of tall trees and help transport water
May also help O2/CO2 exchange by increasing surface area

12

ADAPTATION: Leaves with flexible bases

Flexibility in base helps leaves turn to face the sun

13

ADAPTATION: Thin smooth bark

Allows water to flow down tree easily and stops other plants from growing on tree surfaces

14

ADAPTATION: Epiphytes

Plants which live on trunks and branches of other plants, allowing them to make the most of the sunlight in the canopy

15

ADAPTATION: Emergent

Fast-growing trees (e.g. Capoc) out-compete other trees to reach sunlight

16

ADAPTATION: Drip-tip

Allows heavy rain to drip off leaf. This prevents algae growing which could block sunlight and stop photosynthesis

17

Nutrient cycle:

1) Trees shed leaves all year round
2) Decaying vegetation decomposes rapidly releasing nutrients
3) Nutrients enter the soil surface but don't get the chance to sink in
4) Shallow roots quickly take up the nutrients
5) The nutrients help the tree grow rapidly
*repeat*

18

Deforestation

The cutting down of trees on a very large scale, often to make profit

19

Deforestation in the Amazon for resource exploitation
-LOGGING

-Timber companies are interested in selectively logging mahogany and teak because they can be sold to other countries to make furniture
-Smaller trees are used for fuel or made into pulp or charcoal

20

Deforestation in the Amazon for resource exploitation
-MINERAL EXTRACTION

-Most of the mining is for gold
-In 1999 there was 10,000 hectares of land being used for gold mining
-Today, the area is over 50,000 hectares

21

Deforestation in the Amazon for resource exploitation
-ENERGY DEVELOPMENT

-Hydro-electric power is an ideal energy source due to the unlimited supply of water and ideal river conditions for HEP dams
-Trees have to be removed because reservoirs need to be stored for water
-HEP dams have short lifespans in the rainforest because they become blocked with soil washed down deforested slopes by heavy rain

22

Deforestation in the Amazon for resource exploitation
ILLEGAL TRADE IN WILDLIFE

It is endangering species (e.g. Jaguar) and upsetting the natural balance of the rainforest ecosystem, therefore degrading it

23

Deforestation in the Amazon for use of the land
-COMMERCIAL FARMING: CATTLE

-Livestock rearing in Brazil is said to account for 80% of all rainforest destruction
-The land cannot be used for long since the quality of the pasture quickly declines
-The cattle farmers then have to move on and destroy more rainforest to create new cattle pastures *repeat*

24

Deforestation in the Amazon for use of the land
-COMMERCIAL FARMING: CROPS

-The amount of rainforest cleared for the soybean crop doubled between 1990 and 2010
-This is due to being and important ingredient in many food products and the main food source for cattle
-Soil will not sustain crops for long, so after a few years the farmers have to cut down more rainforest for new plantations *repeat*

25

Deforestation in the Amazon for use of the land
-SETTLEMENT AND POPULATION GROWTH

-All deforestation activities need workers, and workers and their families need homes and services
-This creates a knock-on effect, causing even more deforestation
-The Brazilian government offers land in the rainforest to poor people from overcrowded cities to provide cheap labour since they could work and live in the rainforest for minimum wages

26

Deforestation in the Amazon for use of the land
-ROAD BUILDING

-Roads are needed to bring equipment and transport products to markets, but road-building means cutting through the forest
-A road built for one particular commercial activity makes the forest accessible to other exploiters of the rainforest resources
-The Trans-Amazonian Highway began construction in 1972 and is 4000km long
-Only a small part of it is paved, but paving brings even more destruction and cuts down more trees

27

Selective logging

Cutting down trees that are mature or inferior to encourage the growth of the remaining trees in the rainforest
-cause

28

Mineral extraction

The removal of solid mineral resources from the earth (e.g. Ores and precious stones)
-cause

29

Biodiversity reduced

The number of different species of plants and animals will decline
-impact

30

More carbon dioxide released into atmosphere

This will lead to changes to our climate
-impact

31

Commercial farming

Farming to sell produce for a profit to retailers or food processing companies
-cause

32

Subsistence farming

A type of agriculture that only benefits the farmer and their family
-cause

33

Logging

The business of cutting down trees and transporting the logs to sawmills
-cause

34

Soil erosion

Removal of topsoil (the nutrient rich layer of soil) faster than it can be replaced due to natural and human activity
-impact

35

Goods

Things that can be directly obtained from the rainforest

36

Services

Benefits that the rainforest can offer for both people and the environment

37

The value of the rainforest: GOODS

-Native food crops (fruit, nuts, cocoa, sugar, vanilla, spices)
-Wild meat and fish
-Building materials (timber)
-Energy from hydro-electric power (HEP)
-Medicines (25% all medicines come from rainforest plants) e.g. Periwinkle: vinblastine increased chance of surviving childhood cancer from 10-95%; vincristine treats Hodgkin's disease

38

The value of the rainforest: SERVICES

-Biodiversity (TR contain half of the world's plants and animals)
-Air purification (28% the world's O2 comes from the rainforest)
-Protection against soil erosion
-Wildlife habitats
-Nutrients recycling
-Water recycling (20% world's fresh water come from Amazon Basin)
-Employment opportunities

39

Strategies to manage tropical rainforests sustainable:

-Selective logging and replanting
-Conservation and education
-Ecotourism
-International agreements about use of tropical hardwoods
-Debt reduction

40

Rules made by NGOs to stay manage tropical rainforests sustainable (sustainable forest managment = more profit)

1) Clearing of intact rainforests are prohibited
2) Use sustainable management plan
3) Sensitive forest areas are to be preserved
4) The rights of indigenous groups are to be protected
5) Workers are assured of fair working conditions

41

The sustainability certificate and label ensures:

-National legality and assurance systems
-Climate protection
-Sustainable procurement
-Sustainable wood energy supply
-Sustainable construction materials for buildings

42

Sustainability management methods: SELECTIVE LOGGING AND REPLANTING

=fell only fully grown trees, younger trees allowed to mature

+protects ground from erosion, cycle lasts 30-40 years

-trees still being cut down, open to exploitation

43

Sustainability management methods: CONSERVATION AND EDUCATION

=TPRs preserved in conservation areas (e.g. national parks), areas used for education, research and tourism

+education increases awareness of value of TPRs, national parks protect biodiversity

-people may not care despite awareness, still needs money

44

Sustainability management methods: ECOTOURISM

=introduces people to natural world, jobs for locals, money generated used to protect and conserve TPR for future generations

+local people and gov. benefit from retaining and protecting their TPR

-interaction between tourists and locals threaten indigenous cultures

45

Sustainability management methods: DEBT REDUCTION

=agreements between countries to protect TPRs for debt-for nature swaps

+part of debt to other country cancelled if they ensure the conservation of its TPRs

-not all debt cancelled, country may still need to make a lot of money

46

Sustainability management methods: INTERNATIONAL AGREEMENTS ABOUT THE USE OF TROPICAL HARDWOODS

=products sourced from sustainably managed forests carry the Forest Stewardship Council label

+FSC educates manufacturers and consumers about the need to buy sustainable hardwoods (e.g. mahogany)

-manufacturers will get more money from selling rare and valuable hardwoods