ESS Topic 2 Flashcards
Niche
particular set of abiotic and biotic conditions and resources to which an organism or population responds
Carrying capacity
max no. of species or ‘load’ that can be sustainably supported by a given area,
resource becomes scarce as it nears it,
depends on limiting factors
Limiting Factors
slow down growth of a population as it reaches its carrying capacity
Biotic Factors
living components of an ecosystem that directly or indirectly affect another organisms
Abiotic Factors
non-living physical factors that influence organism and ecosystem
Niche Overlap
if two organisms establish niche in the same area and competition occurs - in mating food and resources
how to avoid niche overlap
different organisms go for different resources - increases survival
Fundamental niche
potential occupied niche
realised niche
portion of fundamental niche a species actually occupies based on other factors impacting where the species actually occupies
S curve
starts with exponential growth - no limiting factors affect growth at first –> however after certain population size growth (carrying capacity) rate slows down resulting in constant population
J Curve
show a ‘boom and bust’ pattern - population grows exponentially at first and then suddenly collapses - often exceeds carrying capacity on a long-term or continuing basis before collapse occurs
diebacks
sudden collapses in J curve
overshoot
when population exceeds carrying capacity on a long-term or continuing basis before the collapse occurs
Competition
interaction between organisms over a resource
Interspecific competition results
balance (shared resource)
or competitive exclusion
Parasitism
relationship between two species in which one species lives in or on another - gaming its food from it
Mutualism
relationship between two or more species in which all benefit and none suffer
Commensalism
a relationship between two species where one benefits and the other is not affected
Respiration
increases entropy of a system while organisms maintains high level of organisation aka low entropy
Primary Producer
makes own food,
provides energy requirements of all other trophic levels,
habitat for tother organisms,
supply nutrients to the soil
Primary Consumer
consumes PP,
keep each other in check through negative feedback loops,
disperse seeds
Decomposer
obtain energy from dead organisms by secreting enzymes that break down the organic matter
Ecological Pyramids
include number, biomass, productivity (energy),
quantative models,
uses - easy examination of energy transfer and losses,
given an idea of what organisms exist at different trophic levels,
help demonstrate that ecosystems that are in balance
Pyramids of numbers
advantages:
simple method of giving overview and good for comparing changes in population numbers over time
disadvantages:
all organisms included regardless of size,
does not allow for juveniles or immature forms,
number can be too great to represent accurately
