WATER AND CARBON CYCLES: UNIT 7 - CARBON STORES

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WATER AND CARBON CYCLES: UNIT 7 - CARBON STORES

IN DIFFERENT BIOMES EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -23 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: Tropical Rainforest's: Deforestation in the Amazon Case Study - McDonalds and Deforestation

Answer:

-Cutting down the forest to grow Soya Beans for their cattle.-Use debt slavery - workers are paid terrible salaries and have to fund own transport.

Solutions:

-Government of Brazil can hold McDonalds accountable.

Question 2: Temperate Grassland - Fact File

Answer:

Location:

-Above the equator on the Northern Continents.-One of the largest temperate grasslands was the USA Priarie Land, of this only 2% remains.

Climate:

-Mild range of temperatures, but distinct seasons.

-Summer: 38+°C

-Winter: -40°C

-250-890mm precipitation / year with the majority as snow in the winter.

Plants:

-Grasses dominate.-Grazed by animals so rarely grows any trees or shrubs.-Soil is perfecet for

agriculture .

Animals:

-Herd based animals: Bison.

-Wolves.-Coyotes.

Soil Quality:

-Unusually rich and fertile - also deep.Question 3: Temperate Grasslands - 'Nutrients Cycle' or Stores & Transfers diagram

Answer:

Stores-

Soil:

-Largest carbon stoe in a temperate grassland.-Built up over time from the seasonal decay.-Extensive root networks help to strengthen its structural integrity and protect it from erosion.-Grasslands store 34% of global terrestrial carbon, in some cases 98% of this carbon is stored in the soil.

Biomass:

-Small due to climate.-Insufficient moisture to support large trees.-Short growing season (6 months) limits growth.-Photosynthesis is therefore seasonal.-Wildfires, and grazing of animals also limit further growth.

Litter:

-Small store as once dead, grasses decay quickly into the soil.-Also, small because much of the biomass is stored underground in roots, so when they die, they decompose and automatically become part of the soil - bypassing the litter store.Transfers- Fallout (Biomass to Litter): Largest transfer. Carbon in biomass is transferred to litter when plants die and animals excrete.Decomposition (Litter to Soil): Bacteria break down the litter that collects at the end of the growing season and add carbon to the soil store.Plant take up (Soil to biomass): The roots of grasses are effective at storing nutrients and water so do not need to frequently replenish stocks. Uptake is therefore small.Inputs- Weathering (Soil): Carbon added through chemical and physical weathering. Wide range of temperature makes rocks vulnerable to freeze-thaw weathering.

Precipitation (Litter): 10-30 inches of rain per year.

Outputs:

Runoff (Litter) Leaching (Soil): Low levels of precipitation, hence loss of carbon from leaching is low.

Question 4: Tropical Rainforest's - Stores & Transfers diagram

Answer:

Biomass is the largest store, Litter is the smallest.Decay pathway is the largest due to high daily temperature and precipitation levels, fallout pathway is the smallest.Question 5: Tropical Rainforest's: Deforestation in the Amazon Case Study - Impacts

Answer:

-Now absorbs just half as much as it did 20 years ago.-Rising temperatures are forcing the Amazon to dry out which leads to less absorption of carbon dioxide and higher susceptibility to wildfires.-Releases up to 20bn tons of water each day.Question 6: Temperate Grassland - Natural flows and stores within temperate grasslands

Answer:

-Grasslands store approximately 34% of global terrestrial stock of carbon.-Primary source of carbon is within the soil.-In Canada, temperate grasslands such as those found in the Great Plains of Alberta, Saskatchewan and Manitoba play a vast role in the global carbon cycle because of their vast areas and high soil carbon density.-Estimated that soils under native grasslands in Western Canada contain around 200 tonnes of carbon per hectare. Therefore, estimated that between 200-300 billion tonnes of carbon are stores there.-The amount of carbon stored under one hectare is equivalen to removing around 150 cars from the Earth for one year.-Influenced seasonally (growing and dormant). In the dormant period no grass can grow because it is too cold.

Question 7: Tropical Rainforest's - Climatic Factors and their influences

Answer:

Temperature:

-Greater heat, more decomposition so more carbon dioxide is released.-More growth, hence more absorption.

Precipitation:

-More photosynthesis can occur as water is necessary.-Greater amount of growth.-Moistness = More decomposition.

Light:

More Light = More photosynthesis Question 8: Tropical Rainforest's - Amazon Rainforest Fact File - Natural flows and stores

Answer:

-Currently, the Amazon is a 'carbon sink' - it absorbs more carbon than it emits.- 2.2 billion tons of carbon dioxide is absorbed by plants in the Amazon rainforest each year.

1.9 billion tons are emitted due to the decomposition.Question 9: Tropical Rainforest's: Deforestation in the Amazon Case Study - Slash-and-burn farming

Answer:

-Fire is used to burn leaves and small trees as it is cheaper to do this than use tractors.-Need to wati 4/5 years before reharvesting so even more land has to be used.-The burnt wood acts as nutrience for the plants.-Over 100,000 hectares of manioc planted which is planted for slash-and-burn every 3 years..Question 10: Tropical Rainforest's - Why are they so important to the Carbon Cycle?

Answer:

-Accounts for

30-50%

of all photosynthesis which occurs in the world.-Store more carbon per unit area than any other biome, 17kg per square metre .-Contain

40-50%

of all carbon stored in the biosphere on land.- 27% of global soil carbon found within rainforests.-At least 40% of carbon in tropical rainfroests is found below ground.