ALL (1, 2, 3)

Topic 1: Foundations of environmental systems and societies Topic 2: Ecosystems and ecology Topic 3: Biodiversity and conservation

enviromental value system

Worldview or paradigm that shapes the way individuals or groups perceive and evaluate environmental issues

Influenced by cultural, religious, economic, and socio-political contexts

ecocentrism

• views ecology and nature as central to humanity

• emphasizes a less materialistic approach to life

• prioritizes biorights, emphasizes the importance of education, and encourages self-restraint in human behavior

athropocentrism

• argues that humans must sustainably manage the global system

• through the use of taxes, environmental regulation, and legislation

• debate to reach a consensual, pragmatic approach

technocentrism

• argues that technological developments can provide solutions to environmental problems

• scientific research is encouraged

• pro-growth agenda

systems approach

a way of visualizing a complex set of interactions which may be ecological or societal

system

an assemblage of parts and their relationship, forming a functioning entirity or whole

comprised of storages and flows

flows

movevement of matter and energy - either transfers or transformations (arrows)

transfer

matter or energy moves through a system without changing state or form (flow)

transformation

a change in state or form (flow)

open system

exchanges both energy and matter across its boundary (ECOSYSTEMS)

closed system

exchanges only energy across its boundary (only experimental)

isolated system

hypothetical concept in which neither energy nor matter is exchanged across the boundary

storages

where energy or matter is held (boxes)

first law of thermodynamics

the principle of conservation of energy - energy in an isolated system can be transformed but cannot be created or destroyed

second law of thermodynamics

the entropy of a system increases over time

(explains the inefficiency and decrease in available energy along a food chain)

entropy

a measure of the amount of disorder in a system

negative feedback loop

STABILIZING - occurs when the output of a process inhibits or reverses the operation of the same process in such a way as to reduce change - it counteracts deviation

positive feedback loop

DESTABILIZING - will tend to amplify changes and drive the system toward a tipping point where a new equilibrium is adopted

resiliance of a system

its tendency to avoid tipping points and maintain stability

(contributed to by diversity and the size of storages)

delay in feedback loop

make it difficult to predict tipping points and add to the complexity of modelling systems

affected by diversity and the size of storages within systems

sustainablility

the use and management of resources that allows full natural replacement of the resources exploited and full recovery of the ecosystems affected by their extraction and use

natural capital

natural resources that can produce a sustainable natural income of goods or services

natural income

the yield obtained from natural resources

ecosystems provide:

• life-supporting services (water replenishment, flood, and erosion protection)

• goods (timber, fisheries, and agricultural crops)

environmental indicators of sustainability

biodiversity, pollution, population or climate

enviromental impact assesment (EIA)

• assess environmental, social and economic impacts of a project (provides decision-makers with info)

• predicts and evaluates possible impacts

• suggests mitigation strategies

  • before - baseline studies

  • after - an audit and continued monitoring

critisms of EIAs

• lack of a standard practice or training for practitioners

• lack of a clear definition of system boundaries

• lack of inclusion of indirect impacts

• not necessarily binding - can be ignored

ecological footprint

the area of land and water required to sustainably provide all resources at the rate at which they are being consumed by a given population

pollution

the addition of a substance or an agent to an environment through human activity, at a rate greater than that at which it can be rendered harmless by the environment, and which has an appreciable effect on the organisms in the environment

• non-point or point source

• persistent or biodegradable

• acute or chronic

pollutants

organic or inorganic substances, light, sound, or thermal energy, biological agents, or invasive species (i.e. from combustion of fossil fuels)

• primary (active on emission)

• secondary (arising from primary pollutants undergoing physical or chemical change).

DDT

insecticide and toxin

→ example of a conflict between the utility of a “pollutant” and its effect on the environment

intrinsic value

when an object or place has a worth irrespective of its economic value

biorights

all life has a right to exist

ecosphere

the planetary ecosystem, including all the earth’s living organisms and their physical environment

litosphere

the rigit outer layer of the earth, about 75 km of the earth’s crust

example of a small system

bromeliad plant in the Amazon river

example of a medium system

a small lake in the Šumava forest

example of a large system

the earth

model

a simplified description designed to show the structure or workings of an object, system or concept

steady state equilibrium

the ability to return to a balance after a disturbance

static equilibrium

no inputs, outputs of energy or matter and no change over time (doesn’t occur in nature)

stable equilibrium

if a system returns to its original equilibrium after a disturbance

unstable equilibrium

system that does not return to the same equilibrium after a disturbance, but forms a new equilibrium

tipping point

a critical threshold when even a small change can have a dynamic effect on a system

resilience

the tendency to avoid tipping points and maintain stability through a steady state equilibrium

species

a group of organisms that share common characteristics and that interbreed to produce fertile offspring

biosphere

the part of the planet where organisms live, including the ground and the air

ecology

study of living organisms in relationship to their environment

habitat

the environment in which a species normally lives

niche

the particular set of abiotic and biotic conditions and resources to which an organism or population responds

fundamental niche

 the full range of conditions and resources in which a species could survive and reproduce

realized niche

the actual conditions and resources in which a species exists due to biotic interactions

abiotic factors

the non-living, physical factors that influence the organisms and ecosystems

(temperature, sunlight, pH, salinity, and precipitation)

biotic factors

living components of an ecosystem

the interactions between organisms

predation, herbivory, parasitism, mutualism, disease, and competition

population

a group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding

S and J curves

a generalized response of populations to a particular set of conditions (abiotic and biotic factors)

S curve

(ex.: mammals)

J curve

exponential growth (ex.: colonizing populations - roaches)

carrying capacity (K)

the maximum number of specific organisms a habitat can sustain

limiting factors

slow population growth as it approaches the carrying capacity of the system

(water availability)

community

a group of populations living and interacting with each other in a common habitat

ecosystem

a community and the physical environment with which it interacts

food web

a complex series of interactions showing the feeding relationships between organisms in an ecosystem

respiration

the conversion of organic matter into carbon dioxide and water in all living organisms, releasing energy

glucose + oxygen → carbon dioxide + water

aerobic respiration word equation

photosynthesis

produces the raw material for producing biomass

carbon dioxide + water → glucose + oxygen

photosynthesis word equation

primary producers

• produce their own food using photosynthesis

• form the first trophic level in a food chain

(autotrophs)

→ typically plants or algae

trophic level

the position that an organism occupies in a food chain, or the position of a group of organisms in a community that occupy the same position in food chains

feeding relationships

• producers

• consumers

• decomposers

• modelled using:

  • food chains

  • food webs

  • ecological pyramids

ecological pyramids

quantitative models (usually measured for a given area and time)

• pyramids of numbers

• pyramids of biomass

• pyramids of productivity

bioaccumulation

the build-up of persistent or non-biodegradable pollutants within an organism or trophic level because they cannot be broken down

biomagnification

the increase in concentration of persistent or nonbiodegradable pollutants along a food chain

toxins

accumulate along food chains due to the decrease of biomass and energy

→ DDT, mercury

pyramid of numbers

(can sometimes display different patterns when individuals at lower trophic levels are large)

pyramid of biomass

represents the standing stock or storage of each trophic level (g m^–2 or J m^-2)

(can show greater quantities at higher trophic levels because it’s measured at a fixed point in time)

pyramid of productivity

the flow of energy through a trophic level, indicating the rate at which biomass is being generated

productivity

the conversion of energy into biomass for a given period of time

solar energy unavailable for ecosystems

solar radiation (insolation) that is absorbed by inorganic matter or reflected back into the atmosphere

pathways of energy through an ecosystem

• conversion of light energy to chemical energy

• transfer of chemical energy from one trophic level to another with varying efficiencies

• overall conversion of ultraviolet and visible light to heat energy by an ecosystem

• re-radiation of heat energy to the atmosphere

net primary productivity (NPP)

total amount of energy stored as biomass in producers (energy available for consumers)

NPP

= GPP – R

= gross primary productivity - respiratory losses

gross secondary productivity (GSP)

total energy assimilated by consumers

GSP

= food eaten – fecal loss

net secondary productivity (NSP)

total amount of energy stored as biomass in consumers (energy available for next trophic level)

NSP

= GSP – R

= gross secondary productivity - respiratory losses

carbon cycle

• storages:

  • organic - organisms and forests

  • inorganic - the atmosphere, soil, fossil fuels and oceans

• flows:

  • consumption (feeding)

  • death and decomposition

  • photosynthesis

  • respiration

  • dissolving

  • fossilization

nitrogen cycle

• stores:

  • organic - organisms

  • inorganic - soil, fossil fuels, atmosphere and water bodies

• flows:

  • nitrogen fixation by bacteria and lightning

  • absorption

  • assimilation

  • consumption (feeding)

  • excretion

  • death and decomposition

  • denitrification by bacteria

biomes

collections of ecosystems sharing similar climatic conditions

1. aquatic

2. forest

3. grassland

4. desert

5. tundra

insolation, precipitation and temperature

3 main factors governing the distribution of biomes

tricellular model of atmospheric circulation

explains the distribution of precipitation and temperature and how they influence structure and relative productivity of different terrestrial biomes

zonation

changes in community along an environmental gradient

→ due to changes in altitude, latitude, tidal level or distance from shore (coverage by water)

succession

the process of change over time in an ecosystem involving pioneer, intermediate and climax communities

(patterns of energy flow, gross and net productivity, diversity, and mineral cycling change over time)

early stages of succession

• low biomass

• low gross productivity

• low proportion of energy lost through respiration

• high net productivity

later stages of succession (climax community)

• high biomass

• high gross productivity - balanced by respiration

• ~0 net productivity

r-strategists

• grow fast

• mature early

• produce many small offspring

• give little care to young

→ cockroaches, frogs

favored by natural selection - pioneer communities

K-stategists

• slow growing

• usually large

• have few large offspring

• mature slowly

→ hippopotamus, dolphin, elephant

favored by predictable environments - climax communities

tools for identifying organisms in an ecosystem

• keys

• comparison to herbarium or specimen collections

• technologies

• scientific expertise

Secchi disk

for measuring turbidity