Sustaining ecosystems - Tropical Rainforests
Cycles
Nutrient cycle
There aren't many nutrients in the soil due to rapid absorbtion by plants and high transpiraiton rates as nutrients are required to replace the used ones
Biomass - Large store of nutrients due to the vast majotiy of vegetation in TRFs
Water cycle
High sun intensity means lots of air rises, cools and condenses into clouds which release water as rain
75% of rain that falls on a rainforest is evapourated back into the atmostphere
25% is evapirates directly from vegetation that intercepted the water
Deforestation means there is less moisture in the atmostphere and rainfall declines
Goods and Services
Goods
Medicine
1/4 of drugs used in developed world are derived from plants
Golden trumpet - laxative, roots used to treat jaundice and also discovered to have antibioitic properties
Rosy Periwinkle - 80% of children with lymphocytic leukemia survive due to medicine from the plant, 50 years ago, most of them died
Food
Coffee - market worth $104 billion in 2020
Soya - market worth $120 billion
Coca used in chocolate, prices peaked at $3,100 per tonne
Raw materials
Timber - used for homes by indigenous people, TNCs turn it into furniture for profit
Oil - Lots of oil under rainforests, used in energy production
Rubber - tapped from trees, used to make tyres
Services
Climate
Rainforests account or 55% of global forest above ground carbon stock
Trees in amazon release 20 billion tonnes of moisture a day
390 billion amazon trees suck up water, release it through transpiraiton
Tourism
Many people travel to see animals like Orang-utan in Borneo
These animals are only found in certain places
Brings money to nations, often LIDCs/EDCs, valuable income
Employment
Farmers in tropics earn $500 profit per hectare of land
13.2 million have a job related to the forest sector
Energy
People in rainforest countries rely on rainforest oil, timber, water and minerals
2nd and 3rd largest HEP projects are in the amazon
People in Cameroon use timber fro firewood
Forest floor is hot an damp, decomposition happens very quickly, there is a small nutrient store in litter, as most nutrients are transferred to the soil
120+ prescription durgs come from plants
Threats to the rainforest
Reasons for deforestation
Farming - growings crops and cattle grazing
Mining - oil and gold
Timber
Tourism
Dam construction
Condition
31 millions acres of forest are cut down every year
20% of tree cover was lost between 1970-2018
Palm oil
3 endemic species among thousands of others are being threatended with extinction due to palm oil clearance, Orangutan, Sumatran tires and Javan Rhinos
Malaysia and Indonesia
85% of palm oil comes from Malaysia and Indonesia
3 million jobs exist due to palm oil plantations
Cattle Ranching
Brazil
65% of cleared forest land in Northern Brazil is for cattle ranching
50% of cattle are grown on land that used to be rainforest
One football field of land is cleared every minute
Logging
Timber is harvested to create commercial item like furniture
2 million hectares of Indonesian rainforest are disappearing every year
10 million hectares of rainforest has been lost illegally
3.4 billion m2 of tree cover was removed in 2010
Mining
2008 recession led to increase in gold price, and led to huge numbers of people minng for gold
Peruvian government is placing fines on illegal miners
2018 - highest rate of deforestation in peru
Congo basin
80% of worlds Coaltan supply
Used in electronics
Hydroelectric power
Destroy ecosystems
Constuction requires heavy machinery which need roads
Case Study - Costa Rica
Threats
Between c, deforestation was one of the highest in the the world
32000 hectares of forest cut down each year
Large scale management
Government established protected areas of forest
28 national parks and nature reserves
24% of ocuntries land area is protected
Now the defoestation rate is almost rezo
Small scale management
Ecotourism
Water comes from netural springs are rainwater
Buildings fit inbetween trees
Samasati Nature retreat founded in 1997
Creates local employment while conserving the TRF
Evalutaion
Successful as it has led to reduce deforestation, more medical supplies, less carbon in atm
Many people depend on the rainforest for a living, less socially and economically sustainable
Evaluation
Environmentally and socialy sustainable
However it doesn't benefit the rainforest
Tropical rainforests
Climate
Forest system
When there is a gap in the vegetaiton, trees grow very quickly in order to get the best spot
Floor stays wetter for longer, perfect for decomposition
Forest floor recieves 2% of actual sunlight
Tallest trees have very strong leaves as they are continually battered with precipitation
Tallest trees receive the most sunlight, in the emergent layer
Temperatures range between 26-30, no variaiton between day/night temperature
Reliable stream of rainfall, over 2000mm a year, it usually rains every afternoon as convectional rainfall
Hot and Wet all year round - one seaon
Soil profile
O horizon - nutrient rich soil layer, shallow
Humus layer (decomposed) is thin as minerals rapidly incorporte into soil and decompose
Rapid chemical weatherng throughout the profile, particularly of the origional parent rock, where the soil has formed
Top layers of soil are red due to high concentrations of aluminium oxide and iron oxide
Minerals like Calcium are leached through the soil due to rainfall
Fertility of soil is sustained by replacement of nutrients from dead leaves
Soils are generally shallow and lack minerals
Soils in rainforests are called latosols
Indigenous people
Grow crops from a section of land for 2-3 year, once the nutrients have been used, they move
Indienous people practice shifting cultivation
Amazon supports the largest number of native people
Depend on surroundings for food, shelter and medicines
Payments for Environmental service programme pays landowners directley when they sustainably use land, 18000 families have benefitted
Risen to nearly 60% rainforest cover
36 guests
200 specis of bird on the grounds
Minimised waste generation due to recycling and composting
Managements jobs are held by foreigners so doesn't benefit local people
Greenwood trees were used (ones that were fallen naturally)
No airconditioning
Small number of guests, so small impact
Requires greater imports as less land food to be grown
Some Landowners have planted large plantations of African oil Palms, which lower biodiversity