Class 9 - rivers, lakes and wetlands Flashcards
Where and how big is the largest known area of TP?
Largest known area of tropical peatland is in Southeast Asia (56%, 77% of peat-carbon storage) – often depths over 10 meters
How deep is the South American peatlands compared to SE Asian
South American thinner and contain less carbon
What are peatlands important for?
Significant role in climate change moderation and biodiversity conservation
Where do peatlands occur?
Mainly occur in lowland areas in sub-coastal zones
What trees produce peat?
Tend to be formed by highly productive vegetation such as rainforest trees
How much does TP make up of total peatlands?
11%
What happens when peatland is cnverted to agriculture (often palm oil)
Destroying biodiversity, displace indigenous people, release carbon into the atmosphere
Where is the most intense destruction of peat happening?
In Indonesia and Malaysia
What is peat?
Is a type of histosol soil found in tropical altitudes. Tropical peat is mainly dead organic matter from trees
How much land does tropical peat probably cover ww?
Could be around 380,000 km2 globally
Is peat threatened and by what?
Yes, climate change and deforestation
How much area does TP cover and how much carbon does it store?
TP only covers 0.25% of forests area, they contain 3% of the world’s soil carbon resource
What are some rare animals living in TP?
Orangutan and Sumatran tiger
What commodities come from peatlands?
Commodities such as fruit, bark, resin, latex
What is the vicious cycle happening in TP?
Peatlands are under threat from climate change and they cause more climate change as they get destroyed
Is carbon from peat destruction included in greenshouse gas estimates?
Carbon release from peat destruction is not usually included in greenhouse gas emissions so we are continuously underestimating it
Is peatland a strong ecosystem?
Incredibly fragile ecosystems vulnerable to any disruption
What happens when peat is deforested?
If forest is lost and peatland drains, the surface peat oxidises - flooding
What causes peat to form?
Toxic chemicals (biotoxins) in leaves prevent decomposition – triggering peat accumulation
What forests do peatlands often coexist with?
Some peatland coexists with swamp-forest
When did deforestation really take off?
Since 1970s peat-swamp has been deforested at rapidly increasing rates
Are peatlands sinks or sources?
Deforestation transforming them from sinks to large scale sources
What animals live in congo?
Peatland in central Republic of Congo provides habitat for lowland gorillas and elephants
How much carbon is stored in the peatlands of Congo?
This site contains carbon equal to the 20 year carbon output of the USA
How much carbon is stored in a swamp in Peru?
In the Pastaza-Maranon swamp in Peru, even though it is only 3% of land area in forested Peru, it holds half of carbon
How much peatland is there vs what is recorded now?
It is estimated that there is much more tropical peat than recorded – probably 3 times more
In which areas of the world does peat mainly?
Mainly occurs in Central and South America, Africa, Southeast Asia
Which ecosystems/areas does peat occur in?
Developed in low-lying areas like deltas, floodplains, shallow lakes or meander oxbows
What happens as the peat accumulates and rises?
When peat rises as it accumulates, water input becomes solely from rainfall and it becomes a low-nutrient system
Peat and general pH?
Highly acidic
How old are the oldest peatlands in Asia?
8000 years
At what altitudes does peat occur?
Sites are usually located about 12-20 meters above sea level and this has not changes much in the past 100,000 years
Why is Indonesia the world’s third largest carbon emitter?
Indonesia is the world’s third largest carbon emitter, mainly because of destruction of peat swamp
What conservation efforts are made to try and save peatlands?
There are conservation efforts for example to save the Orangutans. There are other efforts that engage controversially with the palm oil farmers to promote better practices and educate on consequences
How much of peat-forest is protected?
Only 6%
When is it projected that peat will be completely removed in Indonesia?
2030
What are the main issues of peatlands in the Amazon?
Main issues in the Amazon: Deforestation and agriculture, palm oil production, rice fields, mining for minerals, fire, climate change
Where do lakes and wetlands get water from?
Rivers or groundwater
What characterizes Amazon rivers?
Amazonian rivers are very meandering (bending), because the ground is soft and the area is flat
What happens when rivers flow really fast?
Fastest flowing water erodes the river bank, fastest is when it goes down – this leads to backswamps or oxbow lakes
Where is there more oxygen in rivers?
More oxygen upstream than downstream
Define the flood pulse concept
Sometimes the river level is high, sometimes low, this affects life in the river – can vary in just one week with rainfall
What are the colors of the three types of river water in the Amazon?
Blackwater (black tea color), clearwater (clear color), whitewater (milky coffee color)
Characterise blackwater
High transparency, low sediment load, low nutrient load, 3.5-6 ph
Characterise clearwater
High transparency, low sediment, low-intermediate nutrient, 5.5-8 ph
Characterise whitewater
Low transparency, high sediment, intermediate-high nutrient, 6.5-7.5 ph
What is special about lake Victoria and biodiversity?
High diversity of fish species and fast evolution – 500 cichlid species just in lake Victoria, high endemism
What species is especially invasive on lakes and rivers?
The water hyacinth
What is unique about the Okavango delta in Africa?
Okavango delta in Africa finishes in the middle of the dessert – disappears into the ground or evaporates – unique
Define the 3 types of wetlands *2
Rain-fed = ombrotrophic, river-fed = rheotrophic, water from mineral soil-fed = minerotrophic
Oligotrophic = nutrient poor, mesotrophic = nutrient intermidiate, eutrophic = nutrient rich
What would peat become naturally if we left it for long enough?
Coal
How much pure organic matter must there be for something to be peat?
30cm
Campare the features of rivers and lakes
Unidirectional running water towards sea vs standing water. Water from large catchment area vs water from rivers or groundwater. Longitudinal zonation vs vertical zonation. Transportation and deposition of materials vs accumulation of materials
What is the river continuum concept?
What happens upstream affects downstream ecosystems (and other way around)
Define the flood farming cycle
- flood retreats, 2. Plowing, 3. Cultivated floodplains, 4. Crop harvesting, 5. Floodplain is bare. 6. Flood
What fish is causing mass extinction in the nile
The Nile Perch
What is the challenge of soil saturation and flooding for plants?
Plants need oxygen to grow, flooding fill soil pores with water, microorganisms consume oxygen
What are some reasons that peat does not decompose?
poor aeriation, anoxic conditions, biotoxins
