Ecology Lectures 4 - 6 Flashcards
Define: COMPETITION
the INTERACTION between species where and INCREASED growth rate for ONE means a DECREASED growth rate for the OTHER
Define: COMPETATIVE EXCULSION PRINCIPLE
when two species have IDENTICAL species, one will drive the other to EXTINCTION
Define: EXPLOITATAIVE COMPETITION
“INDIRECT” competition between species or individuals for LIMITED RESOURCES in an environment
Define: INTERFERANCE COMPETITION
“DIRECT” competition between species or individuals that IMPEDE on a competitor’s ACCESS to essential RESOURCES.
Define: COEXISTENCE AT A REDUCED CAPACITY
both species continue to LIVE, at LOWER numbers. this is TEMPORARY.
Define: COMPETATIVE EXCLUSION
one species DISAPPEARS from the region. the species BETTER ADAPTED to the NICHE of the environment will SURVIVE.
Define: NICHE PARTITIONING
both species continue to COEXIST, but they DIVERGE slightly to occupy SLIGHTLY different environmental NICHES (new REALIZED NICHE).
Define: CHARACTER DISPLACEMENT
when NICHE PARTITIONING leads to EVOLUTIONARY change
Define: MUTUALISM
interactions where BOTH species are BENEFITTED.
Define: CONSUMPTION
one species BENEFITS and the other is HARMED (ex. predation, parasitism, herbivory)
Define: COMMENSALISM
(hint: sounds like communism)
one species is BENEFITED, the other is NOT AFFECTED
Define: AMENSALISM
one species is HARMED, the other is NOT AFFECTED
Define: ECOLOGICAL NETWORKS
a REPRESENTATION of the BIOTIC INTERACTIONS between species
Define: TOPOLOGY
(Hint: who’s on top?)
who EATS whom.
Define MODULE
SUBSET of species within a web.
Give examples of INDIRECT species interactions.
- humans are PREDATORS to the environment
- INCREASED predator ABUNDANCE caused DECREASED prey ABUNDANCE
- INCREASED prey ABUNDANCE caused INCREASED predator abundance
Define: TROPHIC TRANSFER
elements, energy, and contaminants are TRANSFERRED from one trophic LEVEL to ANOTHER.
Define: BIOACCUMULATION
the gradual BUILD UP of substances, such as toxins or contaminants, in the TISSUE or ORGANS in species over time.
Define: BIOMAGNIFICATION
occurs when the CONCENTRATION of substances, such as contaminants and toxins, INCREASES as you move UP the FOOD CHAIN
Define: FOOD CHAIN
LINEAR sequence of ENERGY FLOW between organisms
Define: TROPHIC LEVEL
a POSITION on the food chain that represents a group of organisms sharing the SAME ENERGY SOURCE
Define: BIOMASS
the TOTAL quantity or weight of organism in an AREA
Define: TROPHIC PYRAMID
relative amounts of BIOMASS within each TROPHIC LEVEL of the FOOD CHAIN
What is the principle of ecological efficiency?
only a FRACTION of the ENERGY and BIOMASS from each trophic level is PASSED UP the pyramid (~10%)
Define: ECOLOGICAL NETWORK
a representation of the BOTIC INTERACTIONS in an ecosystem
What are the four cycles in an ecosystem
- nutrients (primary producer –> primary consumer –> top predator –> decomposer –> primary producer)
- carbon
- nitrogen
- phosphorus
How do nutrient and energy interactions differ in a system?
nutrients cycle, energy flows (linear)
Define: STABILITY
the maintenance of a RELATIVELY CONSTANT population SIZE of a species in a geographical area
What type of ecosystems tend to be more stable?
complex, diverse ecosystems are more stable and have a faster return time (eg. a forest is more stable than a farm)
Define: PERTURBATION
a CHANGE in an ecosystem that DISRUPTS its normal or FUNCTIONAL STATE
What type of ecosystems have stronger interactions (stable or nonstable)?
NONSTABLE
stable interactions are weak, which is why disruption can easily be spread across the web and not disrupt the whole ecosystem.
