Ecosystems Flashcards
What are the effects of deforestation?
Humans are impacting plant and animal life in rainforests.
Deforestation involves chopping down trees, exposing the forest floor to sunlight and reducing the number of trees in the rainforest.
Fewer trees absorb less carbon dioxide through photosynthesis.
Soil erosion increases, reducing the quality of the soil and reducing the ability of rainforests to support large animal populations. Trees that used to catch rainwater and protect the soil have been removed, leaving the soil exposed.
What are the interdependence between climate and soil?
Decomposition happens rapidly because of the humid, warm, and moist climate in a tropical rainforest.
This rapid decomposition creates a nutrient-rich layer of soil and this can allow plants to grow very fast.
The speed of plant growth is tied to the soil and the nutrients within the soil.
Interdependence between plants and animals:
Animals get their nutrition (energy, food, nutrients, and minerals) by eating plants, or by eating animals that have eaten plants themselves.
The vegetation in tropical rainforests is very dense. This means that there is a lot of food for primary consumers and other plant-eating animals. There being a lot of food for plant-eating animals means that there are more of them alive, and therefore, more food for meat-eating animals higher up the food chain.
Because of this, rainforests can support large animal populations.
What are evergreen trees?
Because the trees in a rainforest are evergreen, leaves are dropped gradually and consistently throughout the year.
Warm, humid and moist climate:
Decomposers operate very efficiently in warm, humid and moist conditions. Because of this, any organic matter like leaves is broken down (decomposed) very quickly.
The rainfall mixes with the nutrients from decomposition and the nutrients are then absorbed back into the soil.
Biodiversity and plant life
There are so many plants and so much biodiversity that any nutrients in the soil are quickly absorbed by vegetation or by tall trees through their buttress roots.
What is deforestation used for?
Pasture and cattle ranching: 63% Subsistence farmers: 12% Fire:9% Commercial crop farming: 7% Tree felling and looging: 6% Other activities: 3%
What is the rate of deforestation in the Amazon?
In 2015, the Brazilian President Dilma Rousseff claimed that the rate of deforestation had fallen by 83% and that actually Brazil was going to reforest the Amazon.
However, the policies under President Temer and President Bolsonaro has reversed Rousseff’s plan. In 2019, under Bolsonaro, the rate of deforestation was increasing again.
Economic impact of Amazonian deforestation:
Deforestation has fuelled the economic development of poor countries.
In 2018, Brazil exported $28bn worth of metals. The mining industry creates jobs, exports and helps increase Brazilian people’s standard of living.
Similarly, hydroelectric power plants and cattle farms help to create jobs.
In 2018, Brazil became the world’s largest exporter of beef.
Rio Tinto, an iron ore mining company employs 47,000 people globally and thousands of these are in Brazil.
Environment impact of Amazonian deforestation
Photosynthesis by trees in the Amazon absorbs 5% of the world’s carbon emissions each year (2bn tons of CO2).
100 billion tonnes of carbon are stored in the wood of the trees in the Amazon.
If the Amazon were completely deforested, it would release the 100bn tonnes and also reduce the amount of carbon dioxide taken out of the atmosphere by 2bn tons each year.
Trees anchor soil in the ground, bound to their roots. Deforestation damages the topsoil and once this has happened, the fertility of the ground is seriously damaged.
What is sustainable forestry?
Because monitoring the entire Amazon is very difficult (the area is huge and covers 9 countries), logging businesses can pay for the rights to log a certain area, conditional on meeting certain standards. This is called a system of ‘concessions’.
Mahogany is the most valuable tree grown in the Amazon.
Like the Fairtrade stamp, the Forest Stewardship Council’s stamp of approval shows customers whether their wood products were obtained sustainably. Consumer awareness campaigns and standards aim to help consumers make better decisions.
What is ecotourism?
Ecotourism is tourism that has minimal impact on the environment and that helps support local communities.
Eco-tourism, like the hotel Hix Island House in Puerto Rico could become a major source of income in the future for countries and local people. It also educates tourists and people internationally about their personal impact on the environment.
Manaus in Brazil is a hotspot for eco-tourism and Juma Lodge is a famous eco-hotel.
Guests usually pay high prices and only visit in small quantities to help to limit their impact on the Amazon rainforest.
What is selective logging?
Selective logging involves only cutting down a certain species of tree or trees of a certain age. For example, in the Brazilian Amazon, only very old trees may be logged.
Selective logging preserves the structure of the rainforest. This reduces soil erosion as there are still trees in the area, with their roots binding the soil and their leaves/canopy protecting the vegetation below.
What are community programmes?
Organisations like the Amazon Team work with indigenous people and local people in Colombia, Suriname, and Brazil, helping to protect the rainforest, whilst training local people in skills like growing tea, starches, and cacay trees.
Local people are trained up in skills that can help them earn more money, whilst they learn to farm and grow this produce in a way that is sustainable for the Amazon rainforest.
What are biosphere reserves and protection organisations?
Biosphere reserves are protected areas for conservation.
The biggest protected area in the Amazon is the Central Amazon Conservation Complex (CACC). This area is in Brazil and spans six million hectares. In this area, felling trees and hunting animals & fish is limited.
In Brazil, the IBAMA government environmental agency and the FUNAI government indigenous protection agency are tasked with protecting the Amazon rainforest and its inhabitants.
