Module 4 - Ecosystem Dynamics Flashcards
what is an Abiotic Factor
Abiotic factors refer to all the non-living, i.e. chemical and physical factors present in the atmosphere, hydrosphere, and lithosphere
what is a biotic factor
A biotic factor is a living organism that shapes its environment.
what is the impact of abiotic factors on the environment?
Abiotic factors can directly affect the survival of species in an ecosystem by creating or altering the conditions necessary for their survival. For example, if temperatures in an ecosystem become too hot or too cold, certain species may struggle to survive.
whats the impact of biotic factors on the environment?
Biotic factors can change an environment through predation, competition and symbiotic relationships, which can impact the number of animals in a species and their dynamic in an ecosystem.
what is mutualism?
Mutualism is one type of these relationships where both species involved benefit to some extent with neither species being harmed.
what is commensalism?
Association between two organisms in which one derives benefit from the other without causing it any harm.
what is Parasitism?
Association between two different organisms wherein one benefits at the expense of the other.
what is competition?
Competition occurs when two organisms compete for the same limited resource.
what is Allelopathy?
the chemical inhibition of one plant (or other organism) by another, due to the release into the environment of substances acting as germination or growth inhibitors.
what are ecological niches? give a description for Fundamental and Realized Niches.
Ecological niches tell us about the ecological conditions to which a species is adapted and how the species influences its own ecosystem. There are two major types of ecological niches - fundamental niches (Fundamental niche is the entire set of conditions under which an animal (population, species) can survive and reproduce itself. ) and realized niches (Realized niche is the set of conditions actually used by given animal (pop, species), after interactions with other species (predation and especially competition) have been taken into account.)
what will happen to a population if a disease is involved? give an example.
Such disturbances reduce the abundance of some organisms, cause population growth in others, modify the interactions among organisms, and alter the interactions between organisms and their physical and chemical environments. For example Tasmanian devils have, Devil facial tumour disease (DFTD) which decreases their population size.
what is transects as a Sampling technique?
A transect is a 10-metre-long straight line across the study area. At one-metre. intervals, whatever living thing is under (or above) the tagged mark is recorded.
abiotic examples
Light
Temperature
Water
Shelter
Topography
Chemical components
biotic examples
plants, animals, algae, fungi
what is Symbiosis
organisms living together
what is inhibition
one organism directly prevents the development of a competing organism
what is biospheres relationships
sum of all ecosystems on earth.
what are microhabitats
smaller area within habitat (tree canopy) where organisms experiences different environments compared to overall habitat (temp, humidity, sunlight)
what is Intraspecific competition
competition within a species
what is interspecific competition
competition between multiple species
How do you measure population through sampling techniques?
quadrants, transects, tagging and capture-recapture
what is quadrats
throw quadrat randomly into an area and count the population of a certain species. Used for counting small plants or slow moving, small animals.
what is transects sampling
a method used to study the distribution and abundance of organisms along a line or pathway. this determine variation within the population. Used to count larger plants.
what is Tagging/capture-recapture:
The basic idea is that you capture a small number of individuals, put a harmless mark on them, and release them back into the population. this is to recognise the animals that have already been counted. Use to count animals that move and are hard to identify.
What are adaptations?
characteristics that increase the survival and reproductive chances of an organism in its environment. They are a change that an organism makes in response to the environment but usually begin as variations.
what are structural adaptations
things you can see, body shape, anatomical features that assists an organism to adapt to abiotic or biotic environment e.g. large ears, sunken stomata, flying fish body shape
what are behavioural adaptation
actions that an organism takes to improve survival e.g. seeking shade or shelter, migration
what are Physiological adaptation:
inner body functions e.g. production of concentrated urine, venom, shivering to maintain body temperature, antifreeze in arctic plants
what are palaeontological and geological evidence that can be used to provide evidence for past change in ecosystems?
- Aboriginal rock paintings
- rock structure and formation
- ice core drilling
what is radiometric dating?
Radiometric dating is defined as a method used to establish how old an object is by measuring the amount of radioisotope the object contains against the decay product it contains. this is a way to figure out how old something is based on the fact that all things on Earth contain certain materials that change over time.
what is gas analysis?
Gas analysis is used to extract information from tiny bubbles containing atmospheric gas that becomes trapped in the ice cores. The ice can be crushed to release the trapped gasses, which are then separated out by a gas chromatograph.
what evidence is there of megafauna?
Fossils of super-sized kangaroos, giant birds and the rhino-sized Diprotodon (the largest marsupial ever to roam Australia) were found in the same sedimentary layers as stone tools, leading some scientists to previously claim “unequivocal evidence” of a long overlap of humans and megafauna.
an example of megafauna that has adapted due to evolution.
Australia’s kangaroos
what are evidence of Pangaea
The rock formations of eastern North America, Western Europe, and northwestern Africa were later found to have a common origin. Fossils of common animals found in separate places around the world. The shapes of the continents line up against one another.
what was the cause of mass extinction of megafauna in Australia?
Major climatic and environmental deterioration both locally and regionally, including increased fire, reduction in grasslands and loss of freshwater. As well as the theory that humans hunted megafauna decreasing population sizes.
