HOW DO THE CARBON AND WATER CYCLES OPERATE IN CONTRASTING PLACES

Amazon rainforest

Arctic tundra

Carbon cycle

Water cycle

Carbon cycle

Water cycle

6 million2 rainforest spanning across 7 countries with 70% of it in Brazil. Consistent temperature of around 30 with rainfall gradually increasing throughout the year (highest in march with 325mm)

Humid environments allow decomposition to occur much faster, carbon is consistently released. Lots of flows of water

Geology

Relief

Temperature

Gentle relief allows overland flow and through flow to rivers

Impermeable catchments have low capacity for water storage- rapid runoff

High temperature allows high rates of evaporation and strong convection

Atmosphere-high humidity

Precipitation- 2000mm per year

10% intercepted by vegetation

Stored in soil

Runoff

Evaporation- high temperature and dense vegetation-

Tree growth

Leaves shed/organisms die

Decaying vegetation is decomposed

Shallow roots take up nutrients

Albedo

Net primary productivity

Proportion of sunlight reflected from a surface

The rate at which plant accumulate energy in thr form of organic matter

Changes to the carbon cycle

Changes to the water cycle

Deforestation

Why is it happening

Exploitation of minerals under the soil, building materials, food and medicine, land space

19-73-2013 17,500km2 deforested every year

How is it impacting the water cycle

Less vegetation reduces interception

Vegetation absorbs more solar energy, albedo increases so temperature rises

Breach of water storage capacity in soil, more surface runoff

Increased flood risk , lag time and peak flow increase and less uptake of water form soil

2500g/m2 per year in the amazon

Large trees stroke around 180 tonnes of carbon per hectare above ground and 40 tonnes below ground

The whole rainforest absorbs 2.4 billion tonnes per year and releases 1.7 billion tonnes

Deforestation exhausts carbon biomass stores

Reduces inputs of organic material to the soil so the soil is depleted of carbon and exposed to strong sunlight

There are less decomposers so reduced flops of carbon to the atmosphere

Deforestation. Destroys the main nutrient stores and removes nutrients from the ecosystem

Roots no longer take up nutrients and are washed away by rain

Soils are left unprotected so are eroded by run off

Impacts

Less carbon absorption by photosynthesis

Less carbon stored above and below the ground

Less emissions by respiration but more emissions thrihgh erosion fire and deomposition

Management strategies

Amazon Regional Protected areas

Reforestation projects

Local projects

Deforestation and degradation scheme

Agriculture

Covers and area 20x the size of Belgium

By 2015, 44% of the Brazilian amazon was protected

Sequesters carbon in trees and soils and reduces c02 emissions, re-establishes cycles by reducing run off and loss of nutrients

Difficult to legally implement due to the size

Parcia project in the western amazon aims to develop 1000km2 of timber plantation - 20 million fast growing hardwood that will mature over 25 years

Financial assistance can be given and timber can be transported in the river

Monoculture- biodiversity isn’t replicated

Surui people are protected from illegal logging by planting seeds in deforested areas

Provides income

Encourages logging elsewhere

Provides payment to tribes for abandoning logging

Carbon credits can be purchased by companies and counties to expand their carbon quotas, but encourages emissions

Rotational cropping

Planting crops sequentially on the same plot of land to improve soil health and optimise nutrients

Reduces reliance on one set of nutrients however monocroping can deplete the soil

Arable farming

Growing crops like wheat and barely rather than keeping livestock

Improves productivity

Shifting cultivation

Rainforest grows

Tribes clear small areas

Trees are cut and undergrowth burnt

Houses built on cleared land using the wood

Crops grown and harvested on small plots

Nutrients are washed out of the soil by rain

Land eventually abandoned for more fertile ground

8 million km2 spanning accross Canada Alaska and Siberia average temperature is below -15degrees c low annual precipitation and low biodiversity underline with thick permafrost

Small stores of water in the atmosphere

Low precipitation as snow

Settles as snow as soil is impermeable due to permafrost

Lack of vegetation limits transpiration

Low humidity limits evaporation

Snow and ice melt in the summer

Small wetlands and lakes store water as permafrost can drain melted snow

Permafrost acts as a carbon sink

Temperature

Rock permeability

Relief

Low temperatures so slow decomposition

Flux of carbon when the active layer thaws

Short burst of plant growth- small biomass

Input of carbon into the soil

Microorganisms are active and respire c02

Snow insulted microorganisms allowing decomposition

Active layer then freezes again

Below freeing most of the year , water is stored in the permafrost but shallow active layer thaws in the summer

Low relief and large glacial deposits prevent drainage

Crystalline rocks have low permeability

Temperature

Permeability

Limited plant growth due to lack of liquid water and low temperature , slow decomposition and and small carbon store in biomass

Porosity and mineral composition make rocks impermeable to carbon

Changes to the water cycle

Changes to the carbon cycle

Oil and gas

Why is it happening

Impacts

Oil and gas reserves where discovered in Prudhole bay, Alaska in 1968 with quarries and pipelines being invested in in the 70s and 80s

By 90s is accounted for 1/4 of the USA’s domestic oil production

Diffusion of heat from machinery directly into the tundra has caused melting of the permafrost.

Dust deposition also darkens snow increasing sun absorption as well as the removal of vegetation that insulates the permafrost

Both c02 and ch4 are released estimated 40 million tonnes of c02 emission per year

Oil spillages input c02

Destruction of vegetation reduces photosynthesis and c02 uptake

Melting of the permafrost increases runoff and river discharge

Increased flood risk and increased evaporation in the summer

Drainage disrupted

Management strategies

Insulated ice and gravel pads

Building and pipelines elevated on piles

Drilling laterally

Technology

Refrigerated supports

Roads can be constructed on these to protect the permafrost from melting

Allows cold air to circulate beneath prevents permafrost melting

Oil ands gas can be accessed several km from drilling site using directional drilling over a wide area from a single site, fewer sites are then needed

Less impact on vegetation and permafrost

Computers can find where oil i stored by measuring seismic activity rather than using exploration wells

Exploration is targeted, less land damaged

Stabilise the temperature of the permafrost to prevent melting

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