Unit 2: Ecology and Ecosystem Dynamics Flashcards
Lithosphere
rock layer
Hydrosphere
water layer
Atmosphere
air layer
Biosphere
Organisims
What does the enviroment consist of
*lithosphere
*Hydrosphere
*atmosphere
*Biosphere
Two forms of energy
Potential energy is energy that is stored and kinetic energy is the energy of motion, work, heat and light.
first law of thermodynamics
Energy cannot be created or destroyed
second law of thermodynamics
When energy is transfered there is a net loss
Plants are_____
*producers aka autotrophs (self feeders) and they use photosynthesis to transform solar energy into chemical energy
Chemautotrophs
are found in the deep sea and are also autotrophs. They transform energy from hydrogen sulfide instead of the sun
biological (net primary) production
Net Production = Biomass2 – Biomass1
Where:
Biomass2 is the weight measured at time interval 2
Biomass1 is the weight measured at time interval 1
What does “the earth is closed to matter” mean?
Unlike the constant supply of energy that Earth receives, the planet is described as closed to matter. This means that there is only a limited quantity of chemicals on our planet and must continuously cycle between various parts or reservoirs of the environment
Carbon Cycle
- Carbon present in the atmosphere is absorbed by plants for photosynthesis.
2.These plants are then consumed by animals and carbon gets bioaccumulated into their bodies.
3.These animals and plants eventually die, and upon decomposing, carbon is released back into the atmosphere.
4.Some of the carbon that is not released back into the atmosphere eventually become fossil fuels.
- These fossil fuels are then used for man-made activities, which pump more carbon back into the atmosphere
Nitrogen cycle
- Nitrogen Fixing : Bacteria in the soil convert nitrogen into nitrates which are abosrbed by plants
- Amoniumization: Animals eat the plants and convert the nitrates into amonia.
- the animal dies or produces waste the amonium is returned to the soil
- Nitrification: Bacteria break down the Amonium and convert it back into nitrates
- Denitrification: Bacteria break down some of the nitrates in the soil releasing nitrogen back into the atmosphere
Phospherous cycle
- Over time, rain and weathering cause rocks to release phosphate ions and other minerals. This inorganic phosphate is then distributed in soils and water.
- Plants take up inorganic phosphate from the soil. The plants may then be consumed by animals. Once in the plant or animal, the phosphate is incorporated into organic molecules such as DNA. When the plant or animal dies, it decays, and the organic phosphate is returned to the soil.
3.Within the soil, organic forms of phosphate can be made available to plants by bacteria that break down organic matter to inorganic forms of phosphorus. This process is known as mineralisation.
4.Phosphorus in soil can end up in waterways and eventually oceans. Once there, it can be incorporated into sediments over time.
Intra-specific competition
competition between the same species
Inter-specific competition
competition between at least 2 different species
Symbiosis
Symbiosis is a situation where two species share an intimate relationship.
Mutualism
Where both organisms in a symbiotic relationship benifit from said relationship
Commensalism
Where one organism in a symbiotic relationship benifits without harming the otehr
Paracitism
where one organism in a symbiotic relationship benifits by harming the otehr
Predation
Carnivores (predators) killing and consuming other organisms (prey)
3 aspects of biodiversity
- species richness (# of different species in an ecosystem)
- Species evenness (How abundant each species is - more even = more good)
- Domanance (is there one or more species that have disproportionate populations)
What are the levels of ecology
Population: a group of the same species in an area
Community: All the populations of different species in an area
Ecosystem: All of the populations AND abiotic factors in an area
Landscape: Multiple ecosystems interacting
Positive feedback
When ecosystem components reinforce the same result over and over as time goes on. Population growth is an example of this, where populations continue to grow instead of stabilizing at a specific size.
Negative feedback
Ecosystem components cause different results over time. An example of this would be reeds growing on a river bed prone to flooding - which causes erosion to take place. The roots of the reeds keep the soil in place so even as the river floods, it lessens the effects of erosion.
Ecological niche
the position of a species within an ecosystem, describing both the range of conditions necessary for the persistence of the species and its ecological role in the ecosystem.
Fundamental Niche
the entire set of conditions under which an animal (population, species) can survive and reproduce itself
Realized (narrow) Niche
An organisms fundamental niche after interactions with other species (such as predation) have been taken into account.
Factors influencing biodiversity (5)
Geographic isolation such as living on an island restricts movement and will have a profound influence on the biodiversity in a region.
Environmental factors (temperature, sunlight, food, habitat etc.) will affect diversity too. If a species is not able to survive the stress of drought and extreme heat, for example, it will not be successful in colonizing a region.
Latitudinal Gradient such that biodiversity is highest at the equator and this is largely due to the climatic conditions since temperatures do not vary greatly from one extreme to another, and the amount of rainfall is sufficient to promote and maintain high rates of plant production.
Structural Complexity because with a greater complexity in the physical structure of the ecosystem, there is enhanced opportunity to promote biodiversity. Transition zones (ecotones) and edge effects also enhance biological diversity as described in your text.
Age of the ecosystem has been affected by glaciation across the northern hemisphere that has meant these ecosystems are younger than those of the tropics.
Growth rate
expressed as a %. the number of individuals added - the number of individuals lost
doubling time
how fast a population is growing. doubling time = 70% growth rate so a population with a growth rate of 5% would take 14 years to double in size - which is very fast. A population with a growth rate of 1% would take 70 years to double in size - which is very slow
