ENVS 200 - Final Exam (Key Terms)

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LEC 6-10

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Isolated populations that are connected by immigration and emigration
Temporary change in environmental conditions that causes a pronounced changed in an ecosystem
Primary Succession
Sequence of ecosystem development without influence from prior community
Secondary Succession
Sequence of ecosystem development with influence from prior community
Final stage of succession that is thought to be self-replacing and stable
Food Web
What-eats-what in an ecological community
Trophic Cascades
Predators suppress the abundance or alter the behaviour of their prey, releasing the next trophic level from predation
Inadequate ecological conditions caused by disturbances
Founder-Controlled Community
Communities where all species are good colonists and essentially equal competitors Prio
Priority Effect
Species that arrive first at a site are able to hold it against competing invaders, whatever the outcome would be if they competed as simultaneously arriving equals
Dominance-Controlled Community
Communities where some species are strongly superior competitively
Community Succession
Early species are good colonizers and fast growers whereas later species can tolerate lower resource levels and grow to maturity, eventually outcompeting the early species
Series of communities currently in existence; Can be used to infer what the succession must have been
Trophic Level
Position that an organism occupies in the food web Su
Super Predator
Top-Down Control (Predator Controlled)
Populations of organisms in lower trophic levels are controlled by organisms at the top
Bottom-Up Control
Driven by the presence or absence of the producers in the ecosystem
Structured analyses of large numbers of data sets wtiha. view to discerning consistent trends
Biological Diversity
Variability among living organisms from all sources (includes diversity within species, between species, and of ecosystems)
Degree of variation in life
Species Richness
Refers to the no. of unique species
Species Eveness
Amount of each species in a communtiy and how evenly the species are distributed
Hot Spots
Localiteis known to support a large number of species of a specific favoured group Ec
Broad-brush areas delineated by geogaphy and vegetation
Diversity Index
Measures that combine species richness and the evenness of the equitability of the distribution of individuals among those species
Distribution of abundance across species in a community
Niche Breadth
Diversity of resources used or environments tolerated by an individual/species
Niche Overlap
Situation in which co occurring species share parts of their niche space with each other
Productivity Hypothesis
Emphasizes the importance of climate in determining productivity at the lowest trophic level
Energy Hypothesis
Emphasizes the direct role of energy on organisms throughout the community
Conditions that occur when environment becomes enriched with nutrients, increasing amount of plant growth in waters
Particulate Organic Matter
Rain of chemical energy falling as dead organic matter from the sea surface
Alpha Diversity
Diversity at a local scale
Beta Diversity
Differences among communities within a region
Upsilon Diversity
Diversity at the whole regional scale; Alpha + Beta diversity
Potential Evapotranspiration
Amount of water that would evaporate or be transpired from a staured surface and hence, a measure of atmospheric energy
Net Primary Productivity
Amount of carbon retained in an ecosystem
Anything associated with or occuring on the bottom of a body of water
Predictable Variation
Variation that occurs on a time scale similar to the generation time of the species in a community themselves
Unpredictable Changes
Most naturally viewed as disturbances to a community that changes its composition
Intermediate Disturbance Hypothesis
Communities are expected to contain most species when the frequency of disturbance is neither too high or too low
1st Law of Thermodynamics
Conservation of mass or energy
2nd Law of Thermodynamics
In an isolated system, entropy never decreases
Unavailability of a systems energy to do mechanical work
Trophic Transfer Efficiency
= CE x AE x PE
Inorganic nutrient element is changed into an organic form
Conversion of elements from organic form to inorganic form
Gradual disintegration of dead organic matter by both physical and biological agents
Standing Crop
Bodies of living organisms within a unit area constitute a standing crop of biomass
Mass of organisms per unit area of ground or water, usually expressed in units of energy
Primary Productivity
Rate at which biomass is produced per unit area or volume through photosynthesisG
Gross Primary Productivity (GPP)
Total fixation of energy by photosynthesis
Net Primary Productivity (NPP)
Difference between GPP and energy lost as respiratory heat; Represents actual rate of production of new biomass available for consumption
Secondary Productivity
Rate of production of biomass by heterotrophs
Net Ecosystem Productivity (NEP)
Difference between GPP and respiration of all organisms in an ecosystem
Live Consumer System
Proportion of primary production is consumed by herbivores which are then consumed by carnivores
Decomposer System
Fraction of NPP that is not eaten by herbivores passes through this system
Dead organic matter
Organisms which decompose detritus
Animals that consume detritus
Leibig's Law of the Minimum
Fact that one particular element (usually either N or P), can limit productivity
Phenomenon where in some ecosystems, both N and P are limiting to production
Transfer Efficiences
Proportions of net primary production flowing along each of the possible energy pathways depend on these
Consumption Efficiency
Percentage of total productivity available at one trophic level that is consumed by the trophic level above
Assimilation Efficiency
Percent of food energy taken into consumers in a trophic level that is assimilated across the gut wall and becomes available for incorporation into growth or to do work
Productive Efficiency
Percentage of assimilated energy incorporated into new biomass
Science that addresses the biotic controls on chemistry of the environment and the geochemical control of the structure and function of ecosystems
Source Sink
Refers to sites of such storage of an element
Radiative Forcing
Imbalance between incoming solar radiation and outgoing infrared radiation that results in global warming
Residence Time
Expresses how fast something moves through a system in equilibrium
Production of methane by bacteria in the absence of oxygen
Collective name given to various actions we can take to slow down or reverse losses of species and biodiversity
Critically Endangered
Considered to be more than 50% probability of extinction in 10 years or three generations
If there is more than 20% chance of extinction in 20 years or five generations
If there is a greater than 10% chance of extinction in 100 years
Near Threatened
If the species is close to qualifying for a threat category
Of Least Concern
Species that do not meet any threat categories De
Identical alleles from mother and father
Inbreeding Depression
Deleterious effects that result from having homozygous alleles
Populations are harvested at a rate that is unsustainable, given natural rates of mortality and capacities for reproduction
Invasive Species
Organism that is not native to an area
Extinction Vortex
Population may have been reduced to a small size by 1+ processes which leads to increased frequency of mating among relatives and deleterious recessive alleles in offspring, leading to reduced survivorship and fecundity and causing population to further shrink
Mutualism of a fungus and an algae
Poikilohydric Organisms
Absorb water from their environment straight through their cortex
Combined Sewer Overflow
Pipe that, during storms, discharges untreated wastewater from a sewer system that carries both sanitary wastewater and stormwater; No longer used
Constraint Planning
Landscape is viewed as having cultural and historic features, and abiotic and biotic features which provide both constraints and opportunities for development.
Created by rain that soaks into the ground and flows until it collects above an impervious zone
Volume of porous rock of unconsolidated deposits that can store ground water
Riparian Zone
Zone of transition from an aquatic to a terrestrial zone
The amount of precipitation not absorbed into the ground that flows into surface water bodies or into the storm sewer system
Sanitary Sewer
A sewer used to collect used water from buildings including sewage and grey water
Storm Sewer
A sewer used to collect runoff from streets, roofs and parking lots
Special manholes along storm sewers that remove oil & pollutants from the water.
Storm Water Management Pond (SWM Pond)
Provides storm water flow control, recharges groundwater, and improves water quality by enhancing removal of pollutants.
Urban Heat Isalnd
Where there are higher temperatures in a built-up environment, for example a city, due to human activity –highly reflective surfaces, automobile exhaust, buildings, etc., when compared to rural areas.
All the land and tributaries draining to a body of water.