Case studies old Flashcards

Question

Mass Extinction - The End Triassic extinction

Answer 1

- About 199-214 million years ago - CO2 & GHGs levels quadrupled (global warming) - Massive amounts of lava erupted from the mid Atlantic rift which led to the break up of Pangea - It killed 80% of all species

Answer 2

- 146-65 million years ago - Meteor strike in Yucatan, Mexico - Dust, debris & Sulphur dispersed in the atmosphere - Frequency of wildfires & tsunamis increased - Global warming - Killed 76% of all species

Answer 3

- 299-251 million years ago - Siberian traps eruption releases CO2 and other GHGs in the atmosphere - Lead to global warming and acid rain - Drastic decrease in water and oxygen levels - Wiped out 90% of species

Answer 4

- 359-299 million years ago - crash in CO2 concentration in Earth's atmosphere - Then a succeeding period of global warming reversed the climatic trend - Remaining rainforests, unable to survive the rapidly changing conditions, were wiped out

Answer 5

- 416-359 million years ago - Oxygen levels fell - Increase in CO2 and other GHGs (potentially due to volcanism) - Lead to acid rain - 75% of species killed

Answer 6

About 439 million years ago. Caused by a drop in sea levels as glaciers formed, then by rising sea levels as glaciers melted. 86% of all species died.

Answer 7

- 542-488 million years ago - Decline in oxygen levels - Formation of toxic Sulphur

Answer 8

- 4570-542 million years ago - prolonged global ice age

Answer 9

American bald eagle. It only lived in North America and, therefore, became the USA's symbol. These birds can live up to 40 years in the wild. They live near large bodies of water and nest in trees. They primarily feed on fish but also eat smaller animals like rabbits. In the 1700s, there were 300,000 - 500,000 birds, and their population size declined to fewer than 500 pairs by the early 1960s. This was mainly due to shooting them, using pesticides on crops, destroying their habitats, etc. DDT caused their eggshells to become thinner. The population size was restored by banning DDT and having laws protecting them. In 2007, there were 10,000 pairs of them, and they were removed from the list of endangered animals.

Answer 10

- The bengal tiger, found in parts of india, sub and tropical rainforests - indochinese, parts of thailand and neighbouring regions hilly and mountanious - siberian found in eastern russia and northern china, temperate forests and sikhote alin mountain range - Habitat loss due to deforestation as a result of ubranisation causing decrease in movment corridors - poaching and illegal trade driven by medicine - genetic isolation auses inbreeding causing reduced genetic diversity

Answer 11

- effective seed dispersers help coniferous forest regeneration - forgetting seeds they collect - middens create micro habitats supporting higher abundance - found in woodland habitats - invasive grey squirrel is competiton - habitat loss and fragmentation as a result of climate change causing drier and warmer climates

Answer 12

Habitat: - wet mountainous areas of the the forest of Northern Costa Rica (Cloud Forest Reserve - Elevation: 2000-2100 m Ecological Role: - both predator & prey (will impact the balance of the food chain) Reason for Extinction: - Introduction of chytrid fungi (invasive species that brought disease) - Very small/niche geographical rage of habitat Consequences of Extinction: - Loss of food source for predators - Overpopulation of prey insects

Answer 13

Habitat: - rain forests of Southeast Asia (Borneo & Sumatra) Ecological Role: - world's largest seed disperses - help forest regeneration Pressure on the Species: - Illegal & unsustainable logging (habitat decrease) - Collection of palm oil (plantations) which decrease biodiversity - Destroying native rainforest for monoculture Conservation Efforts: - Preventing deforestation - Orangutan population rehabilitation - Reducing illegal activities

Answer 14

Habitat: - Temperate forests in the mountain ranges of south central China Ecological Role: - Dispersion of seeds Pressure on the Species: - Habitat loss due to urbanization & timber trade Conservation Efforts: - Reduce habitat degradation - Captive breeding - Raises awareness

Answer 15

- Borders Uzbekistan (S) and Kazakhstan (N) - 4th largest sea in the 1900s - Soviet engineers took 1/3 of the water form the Amu Darya & Syr Darya (tributaries) to irrigate rice & cotton fields - Caused increase in water withdrawn - in 1980 only 10% of the original water flow reached the sea - in 1989 the water body split in 2 (N & S Aral Sea) - 2009 - sea lost 1/2 of its surface and 3/4 of its volume (collapse of fishing industry) - Desertification & pollution of remaining water (pesticides & fertilizers) - People had to turn to groundwater source for water - Overabstraction & water scarcity - Lake became salinized (loss of biodiversity) - no lake = no climate regulation - More extreme weather (dust storms) which carried toxic minerals & heavy metals from lake bed - lead to increased respiratory disease and mortality - Reached Kyrgyzstan mountain peaks, which melted (lead to loss of water source & agriculture)

Answer 16

*Management Approaches NEWFOUNDLAND Overreliance on Total Allowable Catch (TAC) system Failed to account for bycatch and discards No effective enforcement of fishing regulations Continued issuing licenses despite declining stocks Prioritized short-term economic gains over sustainability Iceland: Implemented Individual Transferable Quota (ITQ) system Strict enforcement of 200-mile Exclusive Economic Zone Real-time monitoring of fish populations Seasonal closure of spawning grounds Strict mesh size regulations to protect juvenile fish Limited number of fishing licenses Required use of selective fishing gear

Answer 17

Newfoundland: Complete collapse of cod population (99% decline) Trophic cascade affecting entire marine ecosystem Increase in shellfish populations (prey release) Shift in marine food web structure Destruction of seafloor habitat from trawling Loss of genetic diversity in cod populations Changes in zooplankton and phytoplankton composition Seabird population declines Iceland: Maintained cod biomass above critical levels Protected spawning grounds preserved genetic diversity Minimal impact on marine food web Sustained ecosystem balance Limited bottom trawling damage Maintained predator-prey relationships Protected marine mammal populations Preserved marine biodiversity

Answer 18

Japanese Commercial Whaling: Initially conducted under IWC "scientific whaling" loophole Left IWC in 2019 to resume commercial whaling Uses modern factory ships and technology Sets self-determined quotas (typical 383 per year) Targets multiple species (Minke, Bryde's, Sei whales) Government-subsidized industry Focus on commercial markets and profit Operates in exclusive economic zone and Pacific Inuit Traditional Whaling: Aboriginal Subsistence Whaling (ASW) permits under IWC Community-based quotas based on cultural needs Traditional hunting methods with modern safety gear Strict sharing practices within communities Limited to specific species (mainly Bowhead) Regulated by co-management agreements Focus on cultural preservation and food security Operates in traditional territories

Answer 19

Japanese Whaling: Industrial-scale removal of large marine predators Disruption of marine food webs Potential impact on whale population recovery Bycatch issues with modern methods Acoustic pollution from hunting vessels Risk to endangered species Broad geographical impact Collection of non-target species Inuit Whaling: Limited ecological footprint Sustainable harvest levels Selective hunting of specific populations Minimal impact on whale populations Traditional ecological knowledge integration Lower carbon footprint Localized environmental impact Maintains traditional ecological relationships

Answer 20

Ethiopian Management: Full state control and funding of the project Unilateral decision-making on filling and operation Focus on hydroelectric power generation (6,450 MW) Rapid filling strategy for reservoir Modern dam technology and monitoring systems Self-determined operational guidelines Emphasis on national development and energy export Managed by Ethiopian Electric Power Corporation Downstream Countries' Perspective: Advocating for binding international agreements Push for trilateral management framework Demand for guaranteed water flow quotas Request for drought mitigation protocols Collaborative monitoring proposals Focus on water security Regulated by historical Nile water treaties Multilateral approach to operation ## Footnote Them downstream countries are Sudan, Egypt

Answer 21

Ethiopian Dam Operations: Creation of massive reservoir (74 billion cubic meters) Alteration of Blue Nile's natural flow Changes in sediment transport Local ecosystem transformation Potential climate effects (reservoir evaporation) Modified downstream water temperature Impact on river morphology New artificial lake ecosystem Downstream Effects: Reduced water flow during reservoir filling Changes in Nile flood patterns Impact on agricultural practices Potential soil salinity changes Effect on Nile Delta ecosystem Altered groundwater dynamics Modified river nutrients distribution Impact on wetland ecosystems

Answer 22

Research-Based Management: Designated as Class 1 Forest Reserve Strict protection status with no logging history Research-driven conservation strategies Long-term ecological monitoring programs Collaboration with scientific institutions Comprehensive biodiversity surveys Focus on pristine forest preservation Joint management by Sabah Foundation and research bodies Community Integration: Limited access to protect ecosystem integrity Controlled ecotourism activities Education and awareness programs Training local conservation scientists Employment opportunities for local communities Traditional knowledge integration Sustainable tourism development Capacity building initiatives

Answer 23

ENVIRONMENTAL IMPACTS: Conservation Outcomes: Preservation of primary rainforest Protection of endangered species habitat Maintenance of natural ecosystem processes Carbon storage and sequestration Watershed protection Genetic diversity conservation Climate change resilience Ecosystem connectivity maintenance Scientific Benefits: Long-term ecological data collection Understanding tropical forest dynamics Species discovery and documentation Climate change impact studies Wildlife population monitoring Canopy research opportunities Habitat restoration knowledge Biodiversity baseline establishment

Answer 24

- Located south of the Sahara - Semi-arid marginal land (very close to becoming a desert --> fragile) - Extends across LICs (<$1135 per year) - Gets irregular seasonal rains - Sahara is spreading south due to climate change

Answer 25

- Civil war (13/04/2023 - present) - Janjaweed invaded the Darfur area (people were forced to migrate West) - Overpopulation in refugee camps & high natality rate = high demand for food & resources = deforestation - Refugee farmers brought goats & camels = overgrazing - carrying capacity is exceeded (too many animals per unit area) & trampling

Answer 26

- Scheme trying tor reforest the Sahel - Soil was too degraded to plant anywhere East of Senegal

Answer 27

**Chthamalus stellatus** Physiologically tolerant of entire intertidal zone Can survive in both high and low tide areas Wide temperature and desiccation tolerance Broad salinity tolerance range Capable of settling throughout intertidal zone Flexible feeding requirements Adaptable to various wave exposures Wide substrate compatibility **Semibalanus balanoides** Can survive in mid to low intertidal zones Requires regular water coverage Lower desiccation tolerance Specific temperature requirements Needs consistent food availability Prefers moderate wave action Specific substrate requirements Seasonal breeding patterns

Answer 28

**Chthamalus stellatus** Restricted to upper intertidal zone Limited by competition with Semibalanus Confined to more stressed environments Occupies space above Semibalanus zone Survives in high desiccation areas Adapted to longer air exposure Restricted settlement patterns Limited by predation in lower zones **Semibalanus balanoides** Dominates mid-intertidal zone Competitively excludes Chthamalus Optimal growth in preferred zone Better competitor for space and food Higher growth rates in occupied zone More efficient filter feeding Stronger attachment capability Effective predator resistance

Answer 29

**Galapagos Tortoise** Different shell morphology per island Neck length variations for feeding Size adaptations to available resources Shell dome shape varies with habitat Distinct subspecies per island Feeding strategy adaptations Behavioral adaptations Island-specific traits **Black Peppered Moth** Rapid color change evolution Camouflage adaptation Survival against predation Gene frequency shifts Population dynamics change Phenotypic variation Selection intensity Genetic polymorphism

Answer 30

Emu (Australia): Isolation Factors: Continental drift Geographical barriers Climate adaptation Habitat specialization Australian ecosystem Unique predator pressures Resource availability Breeding isolation Rhea (South America): Isolation Factors: Separation from Africa Habitat fragmentation Grassland adaptation Unique predator pressures South American climate Resource specialization Breeding patterns Ecological niche Ostrich (Africa): Isolation Factors: Original continent presence Savanna adaptation Large predator presence African climate Resource availability Breeding territories Habitat preferences Population distribution Shared Adaptations: Flightless nature Large body size Running ability Similar feeding habits Egg size/structure Social behavior Territorial nature Breeding strategies

Answer 31

Event: - 100000 tonnes crude oil spill off the coast of Cornwall, England (1957) - first oil spill in Europe - 25000 marine birds killed - prevented oxygen and sunlight from penetrating the ocean waters Response: 1. 10,000 tonnes of dispersants were sprayed into the waters (more toxic than the oil itself) 2. using absorbent straw --> 4,000 tonnes of waste recovered on Guernsey and 4,200 tonnes recovered in France. 3. Bombing the oil tanker, spilling oil left into the ocean 4. Setting everything on fire

Answer 32

- Climate change mitigation, adaptation & finance (2015) - 180 parties (Nationally Determined Contributions) - Cut emission of GHGs by 50% by 2030 - Prevent global temperatures from rising over 1.5C at preindustrial levels Methods: - Energy efficiency - Renewable energy use - Carbon capture storage (CCS) - Foregoing fossil fuels - Reduce consumption - Reduce deforestation - Infrastructure upgrade

Answer 33

- Spiral of decay - Global temp. increases - Melting of sea ice increases - Albedo decreases - Solar energy absorbed by Earth's surface increase

Answer 34

- Zebra population increases - Lion population increases (more prey) - Zebra population decreases (more predation) - Lion population decreases (less prey)

Answer 35

- Fungi's hyphae interact plant roots by increasing their surface area = increasing the amount of water and mineral ions that can be absorbed by the plant roots - Orchid seeds may gain the nutrients needed for germination from mycorrhizae - Fungi receive organic compounds, e.g. glucose, Some orchids cannot photosynthesis (rely on mycorrhizal fungi to break down dead matter & provide them with nutrients) - The orchid in this relationship is a heterotroph and not an autotroph - The fungi doesn't benefit from this relationship until the orchid dies, at which point it can access the biological molecules in the orchid's tissues by decomposition

Answer 36

Background: Shifted from anti-natalist ("Stop at Two") to pro-natalist in 1987 due to low fertility. Incentives: Baby Bonus (up to SGD 18,000 for 3rd child), Child Development Accounts, childcare leave, fertility treatment subsidies. Stats: TFR dropped below 2.1 in 1975; 1.10 in 2020; 0.97 in 2023; population growth negative. Challenges: Cultural shift slow, financial incentives insufficient, work-life balance issues | TFR -> Total Fertility Rate

Answer 37

Background: 1979–2015 policy to curb population growth; replaced by 2-child, then 3-child policies. Enforcement: Fines, forced abortions, sterilizations; exceptions for minorities and rural families. Stats: 400 million births prevented; fertility rate fell from ~5.8 (1970) to ~1.7 (2013), now ~1.0; male-biased sex ratio (1.16 boys/girl). Impacts: Aging population, "4-2-1" support issue, gender imbalance, social problems (abandonment, undocumented children). Policy Relaxation: 3-child policy in 2021; low birth rates persist due to cultural factors.

Answer 38

Sustainable Development Goals (SDGs) Promote health (Goal 3), gender equality (Goal 5), and food security (Goal 2). Support family planning and reproductive rights globally.

Answer 39

Agricultural tech boost (1940s–60s) increased food supply. Reduced mortality, supported population growth, aided demographic transition.

Answer 40

Main global energy source, finite and causes high CO2 emissions. Drives industrial growth but leads to pollution, climate change, and resource depletion. Political and economic conflicts often arise over fossil fuel reserves.

Answer 41

Derived from sustainably managed forests, renewable if harvested responsibly. Recycling reduces demand for virgin pulp, lowering environmental impact. Challenges: deforestation if poorly managed, water and chemical use in production.

Answer 42

Coltan Technology Essential for electronics (smartphones, laptops); high demand from tech industry. Diamonds Culture Symbol of wealth, status, and romance; value driven by marketing and rarity perception. Oil Scarcity/Politics Strategic resource; price and value influenced by geopolitical tensions, supply limits.

Answer 43

3 strategic landfills (restored), nearing capacity. New Waste-to-Energy (WtE) incinerators (I- PARK1 in 2025, I- PARK2 in 2030) to reduce landfill use. Incineration reduces waste volume by >90%, generates electricity, but produces ash needing landfill disposal. Concerns: incineration emits carbon, may reduce recycling incentives, not fully sustainable. Daily waste: ~15,725 tonnes; incineration capacity will reach 9,000 tonnes/day, still insufficient.

Answer 44

Development Level Highly developed, global financial hub VS Developing, lower income economy Per Capita Ecological Footprint ~4.7–5.4 global hectares (gha) per person; among highest in Asia VS Much lower, below global average Biocapacity Very low (~0.03 gha per person); large ecological deficit, relies heavily on imports VS Higher biocapacity per capita, smaller deficit Carbon Emissions High per capita (~4.5 tonnes/year); major contributor to footprint VS Much lower per capita emissions Waste Generation High waste production; advanced waste management needed VS Lower waste generation; limited infrastructure

Answer 45

Concrete Housing: Raised plinths with concrete pillars, durable materials (corrugated iron, reinforced bamboo). Elevated attics for flood safety. Enables families to stay safe during floods. Dam Building & Embankments: 139 polders with earthen embankments protect low-lying areas. Regular upgrades to withstand sea-level rise and storm surges. Requires ongoing maintenance. Mangrove Planting: Natural barrier reducing storm surge by 1.5–4 meters. Protects embankments and coastal communities. Enhances biodiversity and traps sediment to combat sea-level rise. Combined with embankments for “green-gray” infrastructure.

Case studies old Flashcards

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