Chapter 2 Flashcards
Ecosystem
system composed of living organisms and their physical environment
Biosphere
is composed of all of the earth’s ecosystems; all are interconnected
Environment
consists of all of the external factors acting on that organism
Abiotic Factors
physical factors; temperature,
salinity, pH, sunlight
Biotic Factors
biological factors; living organisms and their interactions with each other (plants & animals)
Habitat
specific place where an organism is found
Microhabitats
smaller subdivisions of a habitat
Homeostasis
the internal steady state of a cell or an organism
Optimal Range
range of environmental factors to which an organism is best adapted
Zones of Stress
regions above and below the optimal range of environmental variables
Zones of Intolerance
regions where an environmental variable is so far from optimal range that the organism cannot survive
Phytoplankton
are photosynthetic organisms (mostly microscopic plantlike organisms and bacteria) that float in the oceans currents
Ectotherms
animals that obtain most of their body heat from the environment
Endotherms
animals that obtain most of their body heat from metabolism
Metabolism
the sum of all of the chemical reactions that occur within cells
Salinity
a measure of the concentration of dissolved inorganic salts in the water
Solutes
substances dissolved in water
Osmosis
movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration
Nutrients
organic and inorganic materials that an organism needs to metabolize, grow, and reproduce
Limiting nutrients
those that limit the distribution of marine organisms (e.g. Nitrogen)
Eutrophication
the process whereby a body of water becomes enriched with nutrients
Oxygen
byproduct of photosynthesis via phytoplankton, seaweeds, and plants
Geographic Range
geographic area within which a population is found
Aerobic Organisms (aerobes)
organisms that require oxygen; plants, algae, animals, and the majority of marine microbes
Population
is a group of the same species that occupies a specific area
- every population has geographic boundaries
Anaerobic Organisms (anaerobes)
organisms that can survive in an environment that lacks oxygen; deep sea, sediments, salt marshes
Sampling techniques
used to estimate population size
Can estimate size by dividing into smaller plots, counting total in plots and multiplying
Can also estimate size by using mark-recapture methods
Population Density
the number of individuals per unit area or volume
Dispersion
pattern of spacing among individuals within the range
Clumped
densely packed into patches
Uniform
individuals are evenly spaced
Random
spacing unpredictable pattern
Generation Time
average time between an individual’s birth and the birth of its offspring
Survivorship
Refers to how long, on average, an individual of given age could be expected to live
Survivorship Curves
Type I: Low early mortality
Few offspring, Good care
Whales)
Type III: High mortality early
Many offspring, Little care
(Fishes, Bivalves)
Type II: Constant mortality
Life History
Can be divided into three phases: birth, reproduction, death
Clutch Size (fecundity)
number of offspring
produced each time an
organism reproduces
Once
all energy into one event
Repeatedly
must divide energy among maintenance, growth, and reproduction
Age at First Reproduction
Timing can impact reproductive output (earlier) and quality and size (later)
Biological fitness
survival of offspring to reproduce
Recruitment
addition of new members to a population through reproduction or immigration
Larval Settlement
aquatic larvae leave the water column and settle on the bottom
Density-Dependent Factor
population regulating factors that have a greater effect as the population size increases (availability of resources)
Density-Independent Factor
population regulating factors that are not related to population size (climate & weather)
r-Strategist
an organism that reproduces early and produces large numbers of offspring
K-Strategist
an organism that seems to maximize its carrying capacity
Community
a group of interacting populations that inhabit a specific area
Niche
role a species plays in a community
Fundamental Niche
broadest possible niche a population can occupy
Realized Niche
portion of a fundamental niche that a population actually occupies
Interspecific Competition
competition between species
Intraspecific Competition
competition among members of the same species
Competitive Exclusion
local extinction of the less successful competitor in a competitive situation
Resource Partitioning
a process that
allows organisms to share a resource
Herbivores
animals that eat vegetation
Carnivores
animals that eat other animals
Keystone Species
A species that effects the population of any species more that one trophic level away from it.
Symbiosis
situation in which two different organisms live together in close association
Mutualism
both
partners benefit
Commensalism
One partner benefits;
the other does not but
is not harmed
Parasitism
one partner benefits at the expense of the other
Host
member that supports
the parasite and is harmed
by the relationship
Photosynthesis
process whereby the energy of sunlight is captured and stored in organic molecules
Autotroph (producer)
organism that can produce its own food
Primary Productivity
the rate at which energy-rich food molecules are being produced from inorganic materials
Light-Dark Bottle method
experimental method for determining primary production
Light bottle
oxygen levels should either increase or decrease less than dark bottle (depending if Photosynthesis > Respiration)
Dark bottle
oxygen levels should decrease due to respiration (no photosynthesis)
Heterotrophs (consumers)
organism that relies on other organisms for food
First-order (primary consumers)
animals that feed on producers
Second-order (secondary consumer)
carnivores that feed on herbivores
Third order (tertiary consumers)
carnivores that feed on carnivores
Omnivores
organism that relies on other organisms for food
Detritivores
organisms that feed on detritus (animal waste and decaying tissue)
Decomposers
animals that break down the tissue of dead organisms and recycle nutrients
Food Chain
linear feeding relationship that links producers and consumers
Food Web
complex
network of feeding
relationships among
producers and
consumers
Dissolved Organic
Matter (DOM)
lost in
water column
Trophic Levels
position a food chain or web that indicates an organism’s feeding relationship
Ecological Efficiency
the % of energy that is taken as food by one trophic level and passed on as food to the next higher level
10% Rule
on average only 10% of the energy available at one trophic is passed along to the next
Energy Pyramid
represents the flow of energy from one trophic level to the next
Shows that energy decreases with each level and number of organisms it supports
Pyramid of Biomass
pyramid representing amount of all living tissue at each trophic level
Pyramid of Numbers
indicates relative number of all organisms at each trophic level
Biogeochemical Cycle
combination of all biological, physical, and chemical processes that are involved in recycling nutrients in an ecosystem
Precipitation nuclei
airborne particulates that attract water droplets; e.g. Sea salts
Carbon Cycle
CO2 reacts with seawater to form carbonic acid which forms bicarbonate ions which combine with calcium to form calcium carbonate
Pelagic Division
the water portion of the ocean
Water column
water in the ocean
Benthic Division
ocean bottom
Neretic Province
water over
continental shelf
Oceanic Province
water covers
deep ocean basins
Photic Zone
region of the water
column where sunlight can
support photosynthesis
Disphotic (Twilight) Zone
region where not enough light
for photosynthesis
Aphotic Zone
region where
sunlight is absent
Plankton
organisms that drift in ocean currents
Nekton
organisms that are active swimmers and can move against the ocean currents
Neuston
small plankton that float at or near the surface of the ocean
Intertidal Zone
region of ocean
bottom covered with water
only during high tide
Shelf Zone
region of ocean
bottom that extends from the
line of lowest tide to the edge of
the continental shelf
Bathyl Zone
region of ocean
bottom that extends from the
edge of the continental shelf
to a depth of 4,000m
Abyssal Zone
4,000-6,000m
Hadal Zone
> 6,000m
Epifauna
benthic organisms that live on bottom sediments
Infauna
benthic organisms that live in bottom sediments
