Land System Change (module 9)

Question 1

Recall the global distribution of land use, and identify the main drivers/causes of land use change

Answer 1

• Habitable Land and Agricultural Land

Question 2

Identify the control variables and planetary boundaries for land system change, and explain why forest change is the focus of the land system change planetary boundary

Answer 2

Global: Area of forested land as 5 of original forest cover (75%) – 65%
Biome: Area of forested land as % of potential forest ( tropical = 85%, temperate = 50%, boreal=85%)

Question 3

List and describe ecosystem services provided by rainforests

Answer 3

climate regulation - absorbs carbon dioxide through photosynthesis, release O2
soil formation and nutrient cycling - decomposition of organic matter, maintain soil structure, prevent erosion
biodiversity conservation - provide habitat for species
water regulation - store rainfall, reduce soil erosion, maintain water quality, regulate river flow

Question 4

Define resilience in relation to forests.

Answer 4

ability of forest ecosystems to withstand and recover from disturbances while maintaining their structure
- biodiversity
- regeneration capacity
- ecosystem functioning
- adaptive capacity

Question 5

Describe the ways in which land use changes impact the earth system and link to other planetary boundary processes that you have studied.

Answer 5

Biosphere integrity - deforestation and habitat conversion impacts biodiversity and ecosystem functioning, can lead to species extinction
Climate Change - altering the exchange of energy, water, and gases between land surface and temp
- releases stored CO2 into atmosphere
Biogeochemical flows - altering distribution and cycling of nutrients, can lead to increased nutrient runoff and soil erosion
Freshwater use - altering hydrological cycle, increased flooding, changes in surface runoff, and reduced groundwater recharge

Question 6

Explain two “feedback loops” between land use change and other environmental changes in the Amazon and boreal forests

Answer 6

Amazon:
deforestation and climate change feedback loop
- leads to large amounts of CO2 -> climate change
- climate change increases the frequency and severity of droughts and wildfires
- leads to further forest loss and degradation
deforestation and hydrological cycle:
- reduces evapotranspiration and disrupts regional rainfall patterns
- leads to dries conditions -> forest fires and increase risk of degradation
- leads to more frequent droughts and water shortages

Question 7

Describe some strategies that can be used to combat deforestation and the detrimental effects of land use

Answer 7

• protected areas and conservation reserves
• sustainable forest management
• land use planning and zoning

Question 8

Consider reasons that reforestation efforts may fail, and why some areas may not be appropriate for reforestation

Answer 8

• inadequate planning and site selection
• limited access to resources
• biological and ecological factors (invasive species)
• climate change
• highly degraded or disturbed landscapes
• urban and infrastructure development

Question 9

Deforestation consequences on the atmosphere, lithosphere, hydrosphere, and biosphere

Answer 9

Atmosphere - releases large amounts of CO2
- climate change
- can worsen air quality
Lithosphere - soil erosion, loss of biodiversity
Hydrosphere - water cycle alteration, water quality
Biosphere - loss of habitat, disruption of ecological processes