Topic 8 Flashcards
What are the specialised characteristics of tropical rainforests
Warm wet climate means plant grow quickly
Dense leaf cover protects floor from wind and rain and root systems hold soil together
Lack of wind on floor means that plant rely on insects such as bees for pollination ( symbiotic relationships are common in rainforests )
Lots of epiphytes where plants grow on trees for sunlight, they depend on rainfall for water and nutrients
How do changes to the rainforest have knock on effects
Deforestation reduces amount of Co2 being absorbed which increases the greenhouse effect and climate change
Rainforest structure and some adaptions
Emergents: tallest trees, have thick buttress roots to hold the trunks
Main canopy: continuous main layer of trees
Undercanopy: younger trees which have not fully grown yet
Shrub layer: dark from leaves blocking light, shrubs have large leaves to get maximum sunlight
Adaptations of plants
Thick waxy leaves with drip tips to channel water off to stop mould of the leaf being weighed down
Trees have smooth, thin bark because they do not need to protect themselves from the cold
Lianas use trees to climb up to sunlight
Plants drop leaves gradually through the year so they can grow all year
How are some animals adapted to the rainforest
Monkeys have strong limbs to spend all day up in the canopy
Animals are camouflaged to hide from predators or catch prey
Animals can swim across rivers
Adapted to low light levels on forest floor with heighted hearing and smell to avoid predators
How are nutrients cycled through a rainforest
Nutrients are stored as: biomass, dead organic material ( leaf litter ), the soil
Nutrients are transferred between these stores
Why are nutrients rapidly transferred in tropical rainforests
Trees are evergreen, so dead leaves fall all year
Warm, moist climate means decomposers can quickly release soluble nutrients by breaking down dead biomass so nutrients quickly enter the soil
Nutrients are rapidly taken up from rapid plant growth
How do rainforests have high biodiversity
Rainforest has been around for 10s millions of years without climate change which allows time for lots of plants to grow
Layered structure provides lots of habitats, plants and animals adapt to specific environments so lots of species develop
Rainforests are stable environments with constant rain and high temps. This means it’s productive so nutrients can cycle quickly so lots of plants can always grow and animals can always develop
How do rainforests have complex food webs
So many species so many links can develop between components e.g. jaguars eat many different prey
Animals can be both secondary and primary consumers e.g. fruit bats eat fruit and also mice which have eaten grass
Why is the rainforest being deforested
Local demand for fuel wood Mineral resources Electricity ( HEP ) Commercial hardwood ( furniture ) Commercial farming ( palm oil ) Local subsistence farming Demand for biofuels
What environmental impacts does deforestation have
Soil is not held together by roots, can be washed away by rain
Nutrients are washed out of soil by rain not being caught by canopy
Trees remove co2 and burning trees releases co2 so deforestation adds to the greenhouse effect
How can climate change be an indirect threat to the rainforest
Increase in temperature and less rainfall causes drought
Drought causes ecosystem stress as many animals that are adapted to moist conditions die
Drought can also cause forest fires
Why is deforestation rising in areas give examples
E.g. borneo and nigeria
Poverty - more small scale subsistence farmers
Foreign debt - selling goods from rainforests can help countries pay back debt to richer countries
Economic development - road and rail projects to promote development open up areas to logging, mining and farming
Why is deforestation decreasing in some areas give examples
E.g. costa rica and brazil
Government policies - costa rican government has invested in ecotourism and pays landowners to reforest
International condemnation - puts pressure on by naming and shaming deforesting countries
Monitoring systems - e.g. Global Forest Watch ( GFW ) provides satellite data to track forest loss. Stops illegal logging
What is REDD and CITES
Reduced Emissions from Deforestation and forest Degradation
Scheme that aims to reward forest owners in poorer countries for keeping forests
Convention on International Trade in Endangered Species of Wild Fauna and Flora
Agreement to tightly control trade in wild animals and plants
Adavantages of REDD
Deals with cause of climate change and deforestation
Forest is protected so remains a habitat for species
Everyone benefits from reducing emissions
Relatively cheap
Disadvantages of REDD
Deforestation may continue in another area
Aspects of REDD are not clear: rewards can be given from cutting down trees and replacing with palm oil plantations which are low in biodiversity
Local communities may suffer from banning agriculture and mining as they need income from them
Advantages of CITES
The issue is tackled at a global level so endangered species trade is controlled all over the world
Raises awareness of threats to biodiversity by education
Disadvantages of CITES
Although individual species are protected from poaching, their habitat may be destroyed so they can still go extinct
Rules are unclear e.g. on ivory trade
Not all countries are members
What is sustainable forestry
When a forest is used in a way that prevents long term damage, whilst allowing people to benefit from the resources it provides in the present and future
Economic challenges of sustainable forestry
Ecnonomkc benefits only seen long term, effects poorer countries who need income immediately
More expensive so it is difficult to persuade companies to adopt sustainable methods
Funding from IGOs and NGOs, if priorities of the organisations change then the funding will stop
Environmental challenges of sustainable forestry
Replanted trees may not resemble natural forest, entire ecosystem may not be restored
Replanted trees will grow slowly and more forest will be cut down before these trees have matured
Selective logging can damage lots of trees in the process of removing target trees
Social challenges of sustainable forestry
Sustainable forestry provides fewer jobs to locals so many can turn to illegal logging
If a population of a forest area increases then demand for resources increases and not enough resources can be supplied to match demand
What is ecotourism
Tourism that minimkse forest damage and benefits local people
Small amount of people allowed into an area at once
Environmental impacts reduced as litter and wasted are disposed of safely
Provides a source of income for local people
Can raise awareness of conservation which can bring in more money
Local people employed in tourism do not have to log or mine for income so deforestation decreases
What are sustainable farming techniques
These techniques protect the soil so that the land remains productive
Agro - forestry: trees and crops planted at the same time so the tree roots bind the soil and the leaves protect it from heaving rain
Green manure: plants which add nutrients to the soil are planted to maintain soil fertility
Crop rotation: crops moved between fields each year with one left empty so soil can recover
How are Taiga Forests interdependant ecosystems
Plants get nutrients from the soil and provide the nutrients to animals which spread their seeds through their dung
Plants grow slowly in cold climates and decompose slowly. Therefore soil is low in nutrients
Herbivores rely on mosses for food and migrate to where plants can grow for them. Predators follow them
In summer, trees absorb heat from the sun and and shade the ground below, this prevent the permafrost ( which provides water to plants ) from thawing
How do changes to the Taiga ecosystem have knock on effects
Chopping down trees can cause permafrost to thaw which floods land and prevents plant growth.
It also releases trapped greenhouse gases which leads to global warming and climate change ( threatening animals )
How are teees adapted to the Taiga forest
Evergreen - don’t drop leaves and can make best use of available light
Needles instead of flat leaves to reduce water loss from strong, cold winds
Cone shaped to stop snowfall from breaking branches, branches also bendy to stop snapping
Animals’ adaptations to the Taiga
Larger mammals are migratory so they move long distances to find food
Well insulated with thick fur
Can hibernate to conserve energy
White coats to camouflage in snow from predators
Why is nutrient cycling slow in Taiga forests
Trees are evergreen to drop needles all year round
Low temperatires means that litter is broken down slowly as conditions are too harsh for many decomposers
Low soil fertility
Cold climate means plants grow slowly so the rate of transfer of nutrients from soil to plant is low
Why do Taiga forests have low biodiversity
Land was covered by ice until about 15000 years ago so animals have not had time to adapt
Simple structure means less habitats so fewer species
Taiga forests less productive as nutrients are cycled slowly, growing season is short so their is nkt much food and a struggle for survival
Why is the taiga exploited
Logging for softwood - housing, furniture, matches Exploitation of fossil fuels Pulp and paper production HEP Exploitation of minerals
How is acid rain causing loss of biodiversity
Burning fossil fuels release gases which dissolve in water in the atmosphere to make acids which are deposited on plants and soils
It damaged plants’ leaves and makes it harder to cope with cold
It can make soils too acidic to support growth
How is pests and diseases causing loss of biodiversity
Many pests and disease are specific to one species and as there is often a particular species of tree in taiga areas it is easy for them to spread which causes damage
Warming from climate change is making it easier for pests and disease causing pathogens to survive
New pests and disease are arriving so attacks are increasing
How is forest fires causing loss of biodiversity
Forest fires are natural as they allow for new growth
Climate change causes warmer, drier conditions so frequency of fires is increasing
They destroy huge numbers of trees and may alter species numbers as some are better at recolonising burnt areas than others
May also breaks forests up into smaller sections which affects migratory animals which need a lot of space to find food
What is creating a wilderness area
An area that is undisturbed by human activity with the aim of protecting the landscape
What is a national park
Area that is mostly in its natural state that is managed to protect biodiversity and promote recreation
What is sustainable forestry
Ways of harvesting timber from forests without damaging it long term
Strengths of a wilderness area
Highest level of protection
Area is kept as pristine as possible
Cover large area so large scale processes can take place e.g. migrations
Strengths of a national park
May be established to protect particular species
Cover large area
Unsustainable human activity not permitted
Good access for tourists
Strengths of sustainable forestry
Limits can be placed on number of trees felled or size of clear cut areas to allow forest to regenerate
Companies can be required to regenerate the area after logging
Selective logging means means some trees remain to become part of new forest
Challenges of creating a wilderness area
Large areas hard to police
Economic pressure on governments from logging, mining and energy companies who want the resources
Pressure from companies and tourists to build roads to allow greater access
Challenges of national parks
Must take into account the needs of local communities who use land for hunting
Tourism may be required to pay for conservation, but access roads, infrastructure and pollution from tourists may harm ecosystem
Challenges of sustainable forestry
Some countries struggle to reinforce restrictions
May be a lack of clear management or information about the ecosystem
Different groups may not agree with rules and restrictions
Why should the taiga forest be protected
The forests store lots of carbon and deforestation will release this as Co2 which causes global warming
Some species exclusive to taiga forest, can go extinct with destruction of forest
Indigenous people rely on forest for their way of life
Why should the taiga be exploited
Demand for resources is increasing, forests provide the wood, fuel and minerals that people need
Forest industries of logging and mining provides jobs
Exploitation of the forest generates a lot of wealth for countries involved
