1. Section B- The Living World What is a small scale ecosystem?
Within each ecosystem there are often complex interrelationships (links) between the living (Biotic) and non-living (Abiotic).
Biotic are the plants and animals whereas the abiotic is the climate and soil.
How does change affect ecosystems?
Slow natural change have few harmful effects, but rapid change like extreme weather can be devasting.
An ecosystem is a complex system made up of plants, animals and the environment.
They occur at different scales from small ponds to large Tropical Rainforests called Biomes.
Human activities can have any impacts such as:
Agriculture fertilisers can lead to eutrophication. This is where nitrates increase algae, which deplete (reduces) oxygen so fish die.
Hedgerows have been removed to make bigger fields and this has destroyed habitats.
Woodlands cut down.
Producers- plants convert energy from the sun by photosynthesis into carbohydrates (sugars) for growth.
Consumers- get their energy from eating producers, creating direct link in the ecosystem called a food chain and more complex food webs.
Decomposers- dead plants and animals (litter) are broken down by fungi, bacteria and termites which adds nutrients to the soil.
Nutrient cycle- Nutrients produced are used by the plants to grow.
Avington Park Lake, Hampshire
The lake had not be looked after for many years so silt had built up and vegetation had blocked paths. Birds did thrive there though.
In 2014 the lake was de-silted and reshaped. New watering habitats were created to attract new wildlife. It is now successfully supporting a diverse range.

2. Distribution and characteristics of biomes
Characteristics of Tropical Rainforest
Many trees have smooth, thin bark as there is no need to protect the trunk from cold temperatures. The smooth surface allows water to run off easily.
m cold temperatures. The smooth surface allows water to run off easily.
Fan palms have large, fan-shaped leaves that are good for catching sunshine and water. The leaves are segmented, so excess water can drain away and not damage the leaves with the weight of the water.
Rainforests have a shallow layer of fertile soil, so trees only need shallow roots to reach the nutrients. However, shallow roots can't support huge rainforest trees, so many tropical trees have developed huge buttress roots. These stretch from the ground to two metres or more up the trunk and help to anchor the tree to the ground.
Lianas are woody vines that start at ground level, and use trees to climb up to the canopy where they spread from tree to tree to get as much light as possible.
Drip tips can also be found on leaves which allow the water to drip off the leaf otherwise it would start to decay in the warm humid air.
easily.
TRF are formed in layers.
Emergents is the highest layer 35-50m.
Main canopy 20-35m- most productive layer
Lower canopy-10-20m-shaded area
Shrub layer 0-10m-ferns grow due to lack of light.
Soil known as latosol- has rapid nutrient cycle but if forest is cleared rainfall will wash nutrients away this is called leaching.

3. Causes of deforestation in the Amazon
Cattle ranching- is the leading cause of deforestation in the Amazon rainforest. In Brazil, this has been the case since at least the 1970s: government figures show 38% of deforestation from was due to large-scale cattle ranching. Today the figure in Brazil is closer to 70%. Most of the beef is destined for urban markets, whereas leather and other cattle products are primarily for export markets.
Historically, hydroelectric projects have flooded vast areas of Amazon rainforest. The Balbina dam flooded some 2,400 square kilometres (920 square miles) of rainforest when it was completed. Today dams drive deforestation by powering industrial mining and farming projects. Hundreds of dams are planned in the Amazon basin over the next 20 years.
Commercial farming-After the commercialisation of a new variety of soybean developed by Brazilian scientists to flourish in rainforest climate, soy emerged as one of the most important contributors to deforestation in the Brazilian Amazon from the 1990s through the mid-2000s. While forest was converted directly for soy fields, the crop's impact on rainforests was much larger, to get the soy to market new roads had to be built which meant more deforestation.
Mining has had a substantial impact in the Amazon. High mineral and precious metal prices has caused a massive invasions of rainforest lands across Brazil, Venezuela, Colombia, French Guiana, Suriname, Guyana, and Peru. A 2013 study found that the area torn up for small-scale gold mining increased 400% in 13 years.
In theory, logging in the Amazon is controlled by strict licensing which allows timber to be harvested only in designated areas, but in practice, illegal logging remains widespread in Brazil and Peru. Logging in the Amazon is closely linked with road building. Studies show that areas that have been selectively logged are eight times more likely to be settled and cleared by shifting cultivators than untouched rainforests because of access granted by logging roads. Logging roads give colonists access to remote rainforest areas.

4. Impacts of deforestation in the Amazon
What are the rates of deforestation and why do we need the rainforests?
Impact of deforestation in the Amazon:
Reduces biodiversity.
Exposes the ground to soil erosion as now trees and roots to protect the soil.
Impacts local and global climates by reducing photosynthesis, transpiration and the cooling effect of evaporation. There will also be more carbon dioxide in the atmosphere which adds to the greenhouse effect.
Every 2 seconds rainforest the size of a football pitch is lost. Brazil’s rate of loss are at its lowest due to:
Brazil’s government cracking down on deforestation.
Brazil leads the world in conservation, protecting over half of the forest.
Rainforest versus economic development
Most deforestation is driven by profit.
Economic gains
Economic losses
Job creation.
Tax revenue used to supply public services such as education.
Improved transport and infrastructure benefits development and tourism.
HEP cheap and plentiful
Minerals are valuable
Water pollution in an increasingly dry climate may limit supplies.
Fires pollute and destroy vast areas of valuable lands.
Greenhouse effect,
Plants that form profitable medicines may become extinct.
Rainforest tourism could decrease.
Biodiversity- they contain over 50% of all plants and animals in the world.
Medicines- around 25% of all medicines come from rainforest plants
Climate change- rainforests absorb and store carbon dioxide.
Water- rainforest are an important source for clean water
People- indigenous tribes live sustainably e.g. the Kayapo tribe

5. Managing the Amazon Rainforest more sustainably
Ecotourism in the Amazon
A lot of TRF are found in LICs. Many LICs borrow money from richer countries and businesses to help development or help them cope with a natural disaster. The borrowed money has to be paid back with interest, so they allow the destruction of the rainforest to help earn money to pay back the debt. Debt has started to be cancelled under conservation swap. The money is written off if there is a guarantee that the money will be spent on conservation. In 2008 USA reduced Peru’s debt by $25million in exchange for rainforest conservation.
Ecotourism usually involves small-scale tourism. The Yachana ecolodge in the Amazon Rainforest is one example of an ecotourism development. The ecolodge is a guesthouse where a small number of ecotourists can stay. Its basically a small environmentally friendly hotel that is surrounded by nature. The Yachana ecolodge is next to the Napo River - a tributary of the Amazon - which is close to the village of Mondana. It is set in its own, protected, 1200-hectare section of rainforest, which is home to thousands of species of tropical plants and animals. Every room has a view of the river, safe drinking water and a private bathroom with a hot shower. Its dining room serves the guests meals made from locally grown food. Most of the people who work at Yachana are local. They have jobs in the kitchen, dining room, garden - and help to look after the guests and their bedrooms. The lodge also employs Amerindian guides to show guests the forest environment and its creatures, how local people live and how they use plants for medicines
Selective Logging where only some trees are cut down. These tend to be the older or inferior ones so it gives the younger trees a chance to grow. This is less damaging to the forest then felling the whole area. It also allows the forest to regenerate. To remove the fell trees the best ways are horse logging or helicopter logging. Both horses and helicopters drag the felled trees out instead of using trucks and roads.
The Forest Stewardship Council is an organisation made up of businesses, NGOs such as Greenpeace and individuals from all over the world. They mark sustainable sourced timber with their logo so consumers can buy sustainable wood.
Conservation- many countries have set up national parks within the rainforest to protect the trees, though policing this is hard. HIC governments and businesses invest in rainforests to try to promote conservation. Norway have invested $1 billion into the Amazon Fund.

6. Characteristics of hot deserts
Opportunities and Challenges in the Thar Desert
Thar- The Thar desert is the most densely populated desert in the world. It stretches across north-west India and into Pakistan.
Hot deserts are mostly found in a belt between approximately 30 degrees north and south of the Equator. This is largely due to atmospheric circulation. Most occupy dry continental interiors, but coastal deserts also exist such as the Atacama Desert in S. America.
Hot Deserts- Characteristics
Plants can have long roots to get to the water or shallow to get the rain as soon as it happens. Roots can grow horizontal and stay close to the surface to get the rain as soon as it falls.
Seeds can lay dormant for years and germinate quickly when it rains.
Cacti- large stems to store water and thick waxy skin to reduce water loss.
Soils tend to be sandy or stony. Limited leafy vegetation means little organic matter and fertility.
Soils are saline (salty) because evaporation of moisture draws salt to the surface.
Thar- - Opportunities (ggod things)
Minerals- Gypsum used to make plaster and cement. Can be mined here along with feldspar.
Tourism- camel safaris in Jaisalmer.
Energy-solar farm Bhaleri uses solar in the water treatment.
Farming- most is subsistence. Some commercial due to irrigation- maize and mustard
Irrigation- from the Indira Gandhi Canal has made what was once scrubby desert productive.
Climate- less than 250mm of rain. Diurnal temp 40c in day to 0 at night.
Soil is shallow and coarse. Not very fertile due to lack of plant material and dry. Few plants. Mammals tend to be nocturnal. People tend to be nomadic and travel in search of food and water.
Thar- Challenges
Extreme Temps- hard to work outside, causes high evaporation leading to water shortage.
Water supply-High rates of evaporation and low rainfall make finding water difficult. Indira Gandhi Canal has been built(1958), which has helped revolutionise farming.
Accessibility- Very limited roads as the high temperatures can melt the tarmac. Strong winds could also cover the roads with sand. Some places use camels to get around.
Desert Animals Characteristics
Nocturnal rodents live in burrows underground.
Snakes and lizards have waterproof skins which retain the moisture.
Camels can withstand days without water.

7. Causes of desertification on the fragile desert fringe
Opportunities and Challenges in the Thar Desert
Reducing Desertification
Water and soil management- irrigation needs to be managed carefully if salinization is to be avoided. Too much irrigation and/or badly drained schemes build-up toxic salts on the surface.
Contour traps- embankments build along slopes prevent soil being washed away during heavy rainfall.
National Park Status- gives legal protection to areas at risk e.g. national park in the Thar desert.
Tree planting- reduces soil erosion because the roots bind the soil together, and the leaves and branches provide shade, grazing for animals and fuelwood e.g. prosopis cineraria in the Thar desert.
What is desertification?
Is where land is gradually turned into a desert. It occurs mostly in fragile boards on the fringe of deserts. This can be caused by natural and human factors. It threatens one billion people .
Causes of desertification
climate Change- Is resulting in drier conditions and unreliable rainfall in some regions e.g. the Sahel on the southern margins of the Sahara.
Soil Erosion- where vegetation is destroyed, exposing soil which cracks and breaks up making it vulnerable to erosion by wind and rain.
Salinisation- Rapid evaporation of poorly practised irrigation leads to surface salts building-up which kill plants.
Overgrazing- population pressure results in the limited vegetation supporting too many animals.
Over-cultivation- More people need more food which exhausts the soil turning it to dust.
Fuelwood- Population growth increases demand . Trees that are stripped of branches will die
Appropriate Technology
Practical and sustainable approaches to farming address the needs of poor people who are unable to afford expensive machinery
Magic Stones- Stones are placed as a small wall to trap in water in Burkina Faso. This has helped crop yield increase by 50%.