1-B Tropical Rainforests Flashcards
What are the physical characteristics of a tropical equator?
- Climate - warm and wet
- Average temperature is 26C
- 2500 ml of rainfall per year - Vegetation - rich vegetation cover with tall trees (40m)
- Soils - thin and poor due to nutrient cycling:
- warm/humid conditions decomposes litter fast
- rain washes away litter nutrients
- causes infertile soil, but lots of nutrients in large trees
What components are within the interdependent ecosystem of the rainforest?
People/Animals Trees Understory Plants Forest Floor Soil Decomposers
How have plants adapted to poor soils?
- rapid cycling of nutrients
- absorption of sunlight > photosynthesis
- warmth/humidity allows plants to grow all year
- adapted to compete for sunlight and humidity
How have plants adapted to the heat and humidity?
- use circulating water as a cooling mechanism
- waxy leaves with tips that allows water run off
- leaves that can stand large volumes of water
- flexible leaf stems, which allows the leaf to move towards the sun
How have plants adapted to competition for sunlight?
- flexible leaf stems, which allows the leaf to move towards the sun
- the bottom two layers (with less sunlight) acquire their food supply from soil and some plants are parasitic plants (attach themselves to host tree and shares its supply of food and water)
How have animals adapted to the great competition for food?
- certain food can only be eaten by certain animals (e.g. toucans and parrots have strong beaks to crack open hard nuts)
- plants and animals work symbiotically (e.g. bats eat fruit with seeds and disperse seeds)
What are some adaptations of animals, which are other survival strategies?
- camouflage used to hide
- poisonous animals with colourful patterns to warn others (e.g. poison dart frogs)
How can biodiversity be impacted within a tropical rainforest?
As all part of the rainforest are dependent on one another, if one changes, then everything else is affected.
For example:
- By removing trees, the levels of CO2 released into the atmosphere increases. This adds to the greenhouse effect.
- By removing trees, the levels of water uptake reduces, which means that the risk of drought increases. This is bad as it means that plants and animals are more likely to be affected.
How are the rates of deforestation changing?
The rate of deforestation has increased in Asia, Africa and South America. (In Indonesia, deforestation rates has doubled since 2005.)
The rate of deforestation has decreased in 7 countries. (In Brazil, deforestation levels are a record low and 1/2 of the rainforest has a protected status)
However, deforestation still occurs - 31 million hectares per year are cleared
What are the causes of deforestation within Brazil?
Main Resource Exploiting Activities:
1) Logging - to cut trees to sell, make pulp/charcoal or for fuel
2) Mineral Extraction - 50,000 hectares have been cleared today for mining in the Amazon
3) Energy Development - dams are built, which floods and rots areas. This kills wildlife
4) Illegal Trade in Wildlife - endangered species disrupt the biodiversity
Activities that Cause Forest Clearing:
1) Commercial Farming (esp. cattle - 80% of forest destruction) - as pasture quality is low, they keep moving
2) Commercial Farming (esp. crops) - cleared 2x the land from 2010 for soya production. Have to keep moving too
3) Road Building (e.g. Trans-Amazonian Highway) - cuts forest and brings access
4) Settlement + Population Growth - activities require settlements to live in
What are the impacts of deforestation within Brazil?
1) Economic Development - has brought wealth to poor Brazil. In 2008, Brazil made $6.9 billion from trading cattle and it is the world’s second biggest exporter of soy beans
2) Soil Erosion - Brazil is losing 55 mill. tons of topsoil every year because of soil erosion caused by soy farming
3) Contribution to Climate Change - the Amazon contains around 100 bill. tonnes of carbon - deforestation releases this, which causes global warming
What are the goods that come out of tropical rainforests?
High Biodiversity means rich source of goods:
- Rubber, coffee, chocolate and sugar are sourced form the rainforest.
- Undiscovered species might give us new medicines (1/4 of drugs are from the rainforest)
What are the services that come out of tropical rainforests?
Rainforests provide services through their impact on the global climate and local environment:
- It is home to the highest diversity of animal and plant species
- Rainforests absorb 0.7 bill tonnes of CO2 from the atmosphere a year, reducing climate change
- Rainforests stores lots of water, which can be slowly released into the atmosphere, which aids with the water cycle
What can be done at an international level to manage rainforests?
- Inter-gov. agreements on hardwoods & endangered species: Inter. Tropical Timber Agreement - restrict trade of hardwood and all legally felled timber must be marked with a registration number
- Debt Reduction by HICs: (e.g. debt-for-nature swaps)
- E.g. in 2010, US loaned 13.5 mill pounds and Brazil turned the money into a fund to protect rainforests - Conservation and Education by NGOs (e.g. WWF)
- Have education programmes in schools and colleges
- Train conservation workers
- Buy threatened areas and create nature reserves
What can be done at a local level to manage rainforests?
- Selective logging (only fell mature trees and protect ground from erosion)
- Replanting: collect seeds and grow into saplings, and then plant saplings into deforested areas. (new US-Brazil Climate Partnership states to replant 12 mill. hectares)
- Eco-Tourism - educate visitors and increase their appreciation for nature and local cultures.
- Profits stay in local communities
- Minimise consumption of non-resources and minimise ecological impact
