Global Environmental Change (core)! Flashcards

Question

what are the 5 main causes of extinction?

Answer 1

Habitat fragmentation - road building, barriers Agriculture - commercial farming, monocultures Human Overpopulation Deforestation Poaching and hunting

Answer 2

Complexity of life Contraction of biological diversity - genetic, species, habitat Attempt to capture the complexity of life. The variability among living organisms from all sources and the ecological complexes of which they are part, diversity within and between species and ecosystems.

Answer 3

total number of genetic characteristics in the genetic makeup of a species - Genetic variability: tendency of genetic characteristics to vary

Answer 4

Number of different species. Consists of: - species richness (no of diff species/ count of species) - species evenness (quantifies how equal the abundances of the species are, number of each)

Answer 5

Simpsons reciprocal diversity index

Answer 6

Simpson’s Reciprocal Diversity Index (1/D) * D = index (sum of species from i=1 to S * S = total number of species * p = proportion of total individuals (n/N) in the i species i th species - workout proportion of each of species and square them, then sum of all of these gives you D - then do 1/D 1/D increases with eveness!!!! - the higher 1/D is, the more even the species is

Answer 7

Ecological diversity is variation in ecosystems found in region or variation in ecosystems over whole planet. The largest scale of biodiversity, within each ecosystem, there is considerable species and genetic diversity. So the variation of ecosystems found in various regions

Answer 8

- Alpha diversity: diversity within a single habitat or ecosystem (local) - Beta diversity: difference in species between 2 habitats or ecosystems (between habitats) - Gamma diversity: total species diversity in a large region (combines alpha and beta diversity, global/regional)

Answer 9

Local diversity e.g in a habitat

Answer 10

Variability between local diversity - differences between habitats or ecosystems

Answer 11

Total species diversity in a landscape - determined by alpha and beta diversity

Answer 12

Endemism: a term used to describe the usually limited geographical distribution of a taxonomic group A species being unique to a location | When a species is only found in one specific geographic area ## Footnote Can make a species more vulnerable to extinction

Answer 13

Areas of HIGH SPECIES RICHNESS and a high level of endemism are generally high levels of conservation e.g Capetown

Answer 14

- Value derived from the direct role of biological resources in consumption and production - comes directly from resources - e.g. food, medicine timber, fuel, fishing

Answer 15

- Benefits from ecosystem services biodiversity provides - e.g. pollination, climate regulation, water purification, soil fertility

Answer 16

- The value from not using biodiversity but valuing its diversity - appreciating intrinsic value - e.g. knowing it exists, and preserving it for future generations

Answer 17

food medicine biocontrol industrial materials ecotourism fuel wood

Answer 18

Value derived from ecosystem services that support human well-being - derives from functions biodiversity performs - ecosystem processes, services and functioning

Answer 19

A non-use value (feel good or warm glow) is a value associated that does not concern our use, either direct or indirect, of the environment, its resources or services. The current generation places value on ensuring the availability of biodiversity and ecosystem functioning to future generations. ETHICAL - doesn't concern our use but impacts how we feel - mental wellbeing

Answer 20

Physical chemical and biological actions or events that link organisms and their environment E.g. Decomposition, primary productivity, nutrient cycling, fluxes of nutrients and energy - things we don't have to pay for but need

Answer 21

Defined as the benefits provided by ecosystems to humans: - Provisioning- production of food and water. - Regulating- photosynthesis to regulate CO2, control of climate and disease and pests - Supporting- such as nutrient cycling, decomposition and crop pollination. makes sure we have seeds for future generations - Cultural- such as spiritual and recreational benefits. ## Footnote estimated to be worth 25 trillion dollars

Answer 22

Have species that are needed for ecosystem to function Productivity is higher with more species due to more variability e.g bc of more types of chlorophyl, different shaped leaves - Have low, medium and high species

Answer 23

- Used sealed controlled chambers (ecotrons) - Aimed to understand how changes in biodiversity impact ecosystem health and functioning under controlled conditions

Answer 24

Studied how plant diversity affects ecosystem function (greater diversity = boosted ecosystem performance)

Answer 25

Large-scale, long term shift in the planet's weather patterns or average temperatures. Earth has had tropical climates and ice ages in its 4.5billion years. Since the last ice age (11,000 years ago), the temperature has been relatively stable- however recently it's beginning to increase at an alarming rate. Climate change is a component of global change not the other way around!!!!!!!!!!!!!!!!!!!!

Answer 26

Solar activity: how active the sun is. Sun spots. There is some evidence that the little ice age (1450-1850) coincided with periods of reduced sunspot activity. Earth's orbit (Milankovitch cycles: changes from spherical to ellipse. Distance between sun and planet earth fluctuate, directly affecting climate.) Continental drift: The way that land masses and plate tectonics work directly affect climate.

Answer 27

El Nino event: pacific ocean event. ocean warming, moves towards Americas instead of moving away Volcanic eruptions: e.g. 1991 Mt St Helens eruption. Particulates in atmosphere create a belt around planet which absorbs suns energy Greenhouse effect - Needed for life but excess causes global warming. Lots of energy being reabsorbed- warming. Increased rate at which is absorbed is creating current concern.

Answer 28

Jean-Baptiste-Joseph Fourier (1827)

Answer 29

- 1957 - Roger Revelle and Hans Suess ## Footnote They both sound like they should either write fairy tales or make confectionaries

Answer 30

About 427ppm (pre-industrial was ~270)

Answer 31

Ice core, dated using hydrogen isotopes, air bubbles formed when ice was created, measuring CO2 conc in air bubble, can estimate how much CO2 was in atmosphere at that time - CO2 has increased almost exponentially

Answer 32

1. CO₂ (Carbon Dioxide) - Produced by burning fossil fuels, deforestation, etc. - Long atmospheric lifetime. 2. CH₄ (Methane) ~25x more effective at trapping heat than CO₂ over a 100-year period. - Released by livestock, landfills, wetlands, and fossil fuel extraction. 3. H₂O (Water Vapour) - The most abundant GHG naturally. - Acts as a feedback, not a direct driver — warmer temperatures lead to more evaporation, amplifying the greenhouse effect. 4. CFCs (Chlorofluorocarbons) - Man-made compounds (aerosols, refrigerants). - Extremely potent GHGs. - Also destroy ozone, banned under the Montreal Protocol.

Answer 33

sea level rises distribution of biomes & species agriculture patterns in disease human migration

Answer 34

Prediction of rise of 12cm by 2030. 50cm by 2100. 50% of humanity inhabit coastal zones, often most fertile ground. Freshwater resources: Climate change will affect ground water supplies and reserves in many ways. Hard to meet demands of increasing population. ## Footnote There is also a political factor as more than half of the world's water supplies are shared

Answer 35

shift in biome patterns, types of vegetation that are determined by their environment. northward migration

Answer 36

- Photosynthetic pathways change - Reduced transpiration - Often an increased C:N ratio - Increases growth ## Footnote Can affect different species in different ways though (specifically between C3 and C4 plants) - can even affect different genotypes within the same species

Answer 37

Negative effects of climate change partially compensated by increased productivity due to fertilisation effect of CO2. About 5% reduction in global cereal production. Increase disparity in cereal production between developed and less developed countries- developed increased by 5%, less developed declined by 10%. Low temperature constrains on crop production will be lifted in many regions. Some crops will require cold to initiate germination. Pole ward extension of the northern boundaries of crops, Change to primary crops for different countries as boundaries moving north. E.g. Change in wheat peak production location

Answer 38

Impacts on human health: Health is dependent on good environment. Factors that affect health: pollution, inadequate water supply, poor soil. These factors are EXACERBATED by climate change. Main direct effect: heat stress in extreme high temperatures that will be more frequent and widespread. Increased spreading of diseases is a potential concern. Some tropical diseases could spread to mid latitude. Spread of malaria by mosquitos

Answer 39

environmental refugees! having to leave home country as a result of sea level rising and being unable to inhabit and farm food. e.g. kiribati

Answer 40

- Leaf Morphology & Chemistry - Leaves become thicker and more waxy - Higher starch storage - More carbon-based defenses (e.g., tannins, lignin) - Herbivore Interactions - Insects experience lower nitrogen availability in leaves - May eat more to compensate - Potentially slower development - loss of species and land

Answer 41

C₃ plants (e.g., wheat, rice, barley) respond strongly to elevated CO₂: - Up to 40% increase in growth - Enhanced photosynthetic rate - Partial stomatal closure ➝ less transpiration, better water-use efficiency - However they don't acclimate C₄ plants (e.g., corn, sorghum, millet): Smaller benefit (~20% increase in growth) - Already efficient in CO₂ uptake due to carbon-concentrating mechanism

Answer 42

Elevated CO₂ causes: - Increased carbon relative to nitrogen so then caterpillars have to eat more plants to get nitrogen intake - Less protein/nutrient content per unit biomass - High CO2 causes partial closing of stomata, reducing transpiration and making plants more efficient in water usuage - less irrigation needed

Answer 43

- Cool grass, and tundra areas will shrink and have reduced regions - Dry forest, warm grass and tropical rainforest will increase in region

Answer 44

Less distribution, northward movement of butterfly distribution

Answer 45

Classed as point or non-point source.

Answer 46

- Negative effects of climate change partially compensated by increased productivity due to fertilization effect of elevated CO2 - 5% reduction in global cereal production - Pole-ward extension of northern boundaries of most crops - farming will need to change - heat waves - drought - spread of disease

Answer 47

Pollution that comes from a single, identifiable source. Easy to trace and regulate. Like a pipe, drain, or chimney

Answer 48

Pollution that comes from multiple, diffuse sources. E.g. Runoff from agricultural fields (fertilisers, pesticides). Rainwater washing pollutants off roads (oil, heavy metals)

Answer 49

D ranges from 0 to 1. The higher the D, the lower the diversity (because a high value means dominance by one species). D = index * S = total number of species * p = proportion of total individuals (n/N) in the i species - n = the number of individuals of each species. - N = total number of individuals of all species OR: Using the reciprocal 1/D: Low 1/D = dominated by a few species (low diversity). High 1/D = many species with similar abundances (high diversity).

Answer 50

This measures the chance that two individuals you pick at random from a sample belong to the same species. For D: Low D (close to 0) → High diversity (low chance of picking the same species → many species in the system) SO we use reciprocal D, so a low 1/D means low diversity

Answer 51

For a given species richness, 1/D increases with evenness

Answer 52

Diversity within a particular area or ecosystem

Answer 53

Difference in diversity between areas High beta diversity = the sites have very different species. Can be measured by gamma/alpha

Answer 54

Overall diversity across a large region

Answer 55

An ecotron is a big, fancy, high-tech version of a microcosm. It’s a large chamber or set of chambers where scientists can: Simulate real-world environments (like a rainforest, grassland, or desert).

Answer 56

BIODEPTH stands for Biodiversity and Ecological Processes in Terrestrial Herbaceous Ecosystems. It’s a big, European-wide field experiment that studied how biodiversity (number of species) affects ecosystem processe

Answer 57

1827 - Jean-Baptiste-Joseph Fourier

Global Environmental Change (core)! Flashcards

(83 cards)