ESS
ESS TEST 1 – DEFINITIONS:
·Open system: system that exchanges ENERGY and MATTER with the outside
·Closed system: system that exchanges only ENERGY with the outside
·Isolated system: system that doesn’t exchange anything with the outside
·Transfer: movement of energy from one place to another
·Transformation: when the energy changes from one form to another
·1st Law of Thermodynamics: energy cannot be created or destroyed, only changes from one form to another
·2nd Law of Thermodynamics: entropy increases in isolated systems
·Unstable equilibrium: once the equilibrium is lost, it is very difficult to come to the initial position
·Steady state equilibrium: it is very difficult to unstable
oNegative feedback à brings equilibrium
·Neutral equilibrium: nearly impossible not unstable
·Negative feedback-loop: tends to bring equilibrium into a system
·Positive feedback-loop: amplifies the change – brings away a system from its equilibrium
·Tipping point: point where the equilibrium is lost
·Technocentrism: they think that technology provide solution to all the environmental problems
·Ecocentrism: they put ecology and nature as equal to humanity
·Anthropocentrism: they believe that humans should sustainably manage the global system
·Sustainability: the use and management of resources that allows full natural replacement of the resources exploited and full recovery of the ecosystems
·Sustainable development: the development with the ability to meet the need of the actual population without compromising the ability of the future generations to meet their own need
·Natural capital: resources that are managed to provide a sustainable natural income from good and services
·Natural income: portion of the natural capital produced
·Modern Environmental Movement: looks for a sustainable development through changes in policy and individual
·Model: simplification of the reality in order to understand how systems work and how do they respond to changes
oStrengths:
§Allow us to preview changes
§Simplify complex system à easy understanding
oWeaknesses:
§May simplify a super-complex system à bad
§Subjective point of view
·Pollution: the addition of a substance or an agent to the environment through human activity
oTypes of pollutions:
§Organic/Inorganicà pesticides
§Light, sound
§Invasive species: species who are not native and had been introduced
oTypes of origins:
§Point source: single and identifiable source à water – easy to stop
§Non-Point source: no identifiable source à runoff from agriculture
·E.I.A:
oNeeded when some change in an environment is wanted to do – consider the environmental effects
oQuantitative factors:
§Biodiversity – the higher biodiversity, the higher probability that the environment is changed
§Pollution
§Climate Change
·E.I.A: process of evaluating the likely environmental impacts of a proposed project or development, taking into account the inter-related socio-economic, cultural and human-health impacts
oBaseline studies before a development project is undertaken
·PROS:
oAre legally obligatory
oNecessary to know the impacts on the environment
oAlso consider the effect in humans
·CONS:
oThere is no rule on which impact needs to be included à can be manipulated
oLack of information on the effects in the future
·Interactions between organisms:
oHerbivory – primary consumers feed only on plant materials
oPredation: a consumer kills and eats another consumer
§Predators have evolved to kill the prey
·Photosynthesis: process by green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water
·Photosynthesis seen as an open system:
oComing in:
§Water
§Carbon dioxide
§Light
oComing out:
§Oxygen
§Chemicals
§Heat
§Glucose
Definitions Chapter 2:
·Ecological footprint: puts a number on the amount of land that would be needed to provide the resources and assimilate the waste of one person
·Organism: individual living thing that can exist on its own
·Population: a group of organisms of the same species living in the same area at the same time and capable of interbreeding
·Species: a group of organisms capable of interbreeding and producing fertile youne
oAnimals coming from two different animals are infertile
·Population density: the number of individuals in an area
·Carrying capacity: the maximum numbers of individuals that the ecosystem can support
·Photosynthesis: processes by plants transform light energy into chemical energy
·Respiration:
a process in living organisms the production of energy, with the intake of
oxygen and release of carbon dioxide from the breakdown of complex
organic substances
·Ecology: scientific study of interactions between organisms and their environments, focusing on energy transfer
·Symbiosis: close and often long-term relationship between two or more species
oParasitism – a relationship between species, where one organism, the parasite, lives on or in another organism
oMutualism – an interaction between individuals of different species, the result of which is beneficial
·Species – a group of organisms capable of interbreeding and producing fertile young
·Biotic – Resulting from living organisms
oDisease agents – predation – competition
·Abiotic – non-living factors of the environment that affect living organisms and the functioning of ecosystems
oSunlight – water – pH – wind
·Predation – the preying of one animal on others
·Herbivory – the state or condition of feeding on plants
·Habitat – a natural environment of organisms
·Niche – the role and position a species has in its environment
oFundamental Niche: full range of conditions and resources in which a species could survive and reproduce
oRealized niche: actual conditions and resources in which a specie exists due to biotic interactions
·Factors that affect population growth:
oFood
oPredators
oDisease
oNatality
·Exponential population growth: when resources are unlimited – J-shaped curve
·Logistic growth: population expansion decreases as resources become scarce, resulting a S-shaped curve
·Competition: the activity or condition of striving to gain or win something by defeating or establishing superiority over others.
·Community – all the populations of different species that live in same place at same time
·Ecosystem – a biological community of interacting organisms and their physical environment.
·Trophic level– the position that an organism or a group of organisms occupies in a food chain
·Autotroph – typically plants or algae, produce their own food using photosynthesis and form the first trophic level in the food chain
·Phototrophs: organism that uses energy from sunlight to synthesize organic compound for nutrition
·Chemoautotrophs: bacteria which make their own food from other simple compounds
·Heterotrophs: they cannot produce their own food directly from sunlight. They require energy stored in complex molecules
oHerbivore
oCarnivore
oOmnivore
·Food Chains: sequence that shows how each individual feed on the organism below it in the chain
oThey always start with a producer
oThe source of energy is always the sun
oConsumers eat plants, animals, etc.
·Ranking consumers:
oProducers – make their own food
oSecondary consumers – eat primary consumers
oTertiary consumers – eat secondary consumers
·Food web: natural interconnection of food chains and a graphical representation of what eats-what in an ecological community
·Ecological pyramids: differences between the amounts of living materials stored at each trophic level of a food chain
oGive an idea of what feeds what
·Pyramid of numbers: shows the number of organisms at each trophic level of the food chain at one time
oThe length of each bar gives a measure of the relative numbers
oProducers at the bottom – greatest number
oAdvantages:
§Simple easy method of giving an overview
§Good for comparing changes in population over times
oDisadvantages:
§Numbers can be too great to represent accurately
§Some pyramids are inverted
·Biomass: total dry mass of organic matter in organisms or ecosystems
oWe can see how productive an ecosystem is – compare it with others
·How is Biomass is collected:
1.Collect samples and estimate number of species in the ecosystem
2.Sort into trophic levels
3.Dry
4.Measure mass of each trophic level
·Pyramids of biomass: represents the storage of each trophic level
oDisadvantages:
§Impossible to measure biomass exactly
§Organisms must be killed to measure dry mass
§Time of year affects the results
·Pyramid of productivity: Shows the actual transfers and allows for rate of production
oPyramids are not inverted, energy from solar radiation can be added
oDisadvantages:
§Difficult to collect energy data
§Difficult to assign species to a particular trophic level (omnivorous)
·Bioaccumulation: accumulation of a pollutant within an organism or trophic level because they cannot be broken down
·Biomagnification: increase in concentration of a pollutant along a food chain
·Producers: An organism capable of producing complex organic compounds from simple inorganic molecules through the process of photosynthesis (using light energy) or through chemical energy. They are the first level in the food chain