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Lecture 12: Human Ecology - Coggle Diagram
Lecture 12: Human Ecology
Key concepts
Definition of Human Ecology
Study of interactions between humans and their environment
Responses of humans to environmental changes.
Effects of human activities on ecosystems.
Examines how cultural, social, and economic systems influence and are influenced by natural systems.
Interaction Between Human and Ecosystems
Human Social System (tech, knowledge, social organization)
↔ Ecosystem (microorganism, soil, water...):
Inputs: Natural resources (energy, water, food).
Outputs: Waste, pollution, habitat alteration.
Key Drivers: Urbanization, industrialization, population growth, consumption patterns.
Root Cause of Unsustainability: HANPP
(a sustainability metric)
Human Appropriation of Net Primary Production (HANPP)
Definition
: Difference between the NPP (Net Primary Production) available in an undisturbed ecosystem and the NPP remaining after human use.
Measurement
Potential Vegetation (NPP_pot): Theoretical NPP of an undisturbed ecosystem.
Actual Vegetation:
Positive HANPP: When human use (e.g., agriculture, logging) reduces NPP below potential levels.
Negative HANPP: When land conversion (e.g., afforestation) increases NPP above potential levels (rare).
Calculation
HANPP_tot = HANPP_harvested by human + HANPP_land-use conversion
Average HANPP across measured regions = 44%.
China’s HANPP Trends
China's Biomass Consumption
Largest global consumer in 2017: ~1.75 PgC/yr (petagrams of carbon per year).
Projected to increase by 317.6% by 2050, amplifying global ecosystem stress.
China ranks #1 in production-based HANPP, driven by massive industrialization and urbanization.
Consumption vs production (consumption keep increasing
Production-based HANPP (red): Driven by domestic land use (e.g., agriculture, forestry).
Consumption-based HANPP (blue): Includes imports (e.g., soy, timber) to meet deman
Sustainable Development Goals (SDGs)
Relevance to Human Ecology
SDG 12: Responsible Consumption and Production.
SDG 13: Climate Action
SDG 15: Life on Land (combat biodiversity loss).
Human-Driven Ecosystem Loss
Global Change
Climate change, ocean acidification, habitat fragmentation.
Biodiversity Loss
Extinction rates accelerated by habitat destruction and pollution.
Urbanization & Species Invasion
Urban sprawl reduces green spaces; invasive species disrupt native ecosystems.
high-density living on local ecosystems (e.g., Victoria Harbour pollution).
One Health Aquaculture
Balancing aquaculture with wetland conservation