Ecology Exam 2 Flashcards
Classifications of animals
Herbivores, Carnivores, Omnivores, Detritivores
Adaptations to the Thermal Environment (3 classifications)
Homotherm, Poikilotherm, Heterotherm
Describe a homotherm (include example and mechanism of heat regulation)
constant internal temperature, mammals and most birds, endothermy
What is endothermy?
oxidative metabolic heat production via respiration
Describe a poikilotherm (include examples and mechanism)
body temp changes with ambient temp, reptiles and amphibians, solar radiation
Describe a heterotherm (include examples and mechanism)
sometimes regulate body temp, bees and bats, torpor
What is torpor?
reduced energy use by remaining in a state of rest until warming occurs
What does the Q10 Temperature Coefficient tell us?
the factorial increase in metabolism per 10 degree rise in temperature
What does a Q10 > 0 indicate?
the metabolic rate is higher at higher temperatures
What does a Q10 < 0 indicate?
the metabolic rate is higher at lower temperatures
What is the thermal neutral zone?
temperature range where animals maintain constant metabolic rate
what kinds of species would you expect to have narrow or broad thermal neutral zones
narrow: tropical, humans, broad: arctic
What are some other animal adaptations to temperature?
avoiding heat spots, changes in body color/morphology, evaporative cooling
Evaporative cooling
lower body temperatures by increasing water intake to compensate for water loss. ex: cicadas
Adaptations to moisture
hypoosmotic, isoosmotic, hypoosmotic
Adaptations to arid environment
increase water use efficiency, nocturnal, infrequent urination. ex: kangaroo rat
Adaptations to light
circadian rhythm
what is the circadian rhythm
innate cycle of inactivity/activity over 24 hrs to provide synchrony with the environment, set by light and not affected by temp or chemicals
List from smallest to largest the classifications of decomposers
microfauna, microflora, mesofauna, macrofauna, megafauna
examples of microfauna
protozoa, nematodes
examples of microflora
bacteria, fungi
example of mesofauna
mites
example of macrofauna
termites
examples of megafauna
millipedes, earthworms, snails
Major decomposers of animal matter (target protein)
bacteria
Major decomposers of plant matter
fungi
Why is decomposition important?
recycling of finite nutrients
What are the stages of decomposition?
leaching, fragmentation, mineralization
What is leaching?
loss of soluble sugars and dissolved compounds
What is fragmentation?
reduction of organic materials into smaller particles
What is mineralization?
all organic materials become inorganic
What happens to mineralized nutrients?
incorporated into microbial biomass, uptaken by plants, leached out of soil system to water/oceans
inorganic nutrients are ___ into organic matter
immobilized
organic matter is ___ into inorganic nutrients
mineralized
What is the rhizosphere?
the soil region immediately surrounding the roots
The rhizosphere has higher ___ ____ than bulk soil
microbial activities
What are root exudates and what do they do?
simple sugars, amino acids, fatty acids that provide nutrients and energy for microorganisms in soil
What is root sloughing?
roots are dying all the time and are decomposed by microorganisms
what are the internal factors affecting decomposition?
the quality of the litter, simple or complex compounds
what is the simplest but highest quality sugar for microorganisms
glucose
What is a population?
group of the same species that occupy a particular space at the same time that mate & produce fertile offspring
What is a metapopulation?
smaller, separate populations that affect one another and are linked by movement of individuals among them
what is a unitary population/unitary organisms?
unitary organisms have predictable and determinate life. When they die, they die
examples of unitary organisms
humans, bats, caterpillars
what are modular organisms?
Unpredictable, indeterminate life. A module is not dead until all of its component modules are dead.
example of modular organisms
trees, trembling aspen
world’s largest organism species?
clone of aspen trees
population density: crude density
of individuals/unit area
population density: ecological density
individuals/amount of area available as living space
population dispersion: random, example
if position of each individual is independent of others or if the occupation of each spot is equally likely, intertidal clams
population dispersion: spaced/uniform, example
individuals evenly distributed, crops, lawn grasses
population dispersion: clumped, example
individuals are distributed in patches, humans
primary sex ratio
ratio of males to females (100) at conception
secondary sex ratio
ratio of males to females (100) at birth
what is unique about populus tremuloides (dioecious species) at different elevations?
different sex ratios
spacial sex segregation
male and female plants living in different areas/conditions, beneficial for species as a whole
physiological natality
max possible births/female under ideal conditions
realized natality
of successful reproduction actually occurring over a period of time
crude birth rate
of births/1000
age specific birth rate
offspring produced per unit time by females in a particular age class
crude death rate
of deaths per 1000
death rate
of deaths during a given time interval / size of population
horizontal/dynamic life table
following a cohort of individuals until they are dead
dynamic/composite life table
constructed by pooling several horizontal life tables
vertical life table
constructed by sampling individuals of different ages during a single time period
type 1 survivorship (examples)
most organisms die late in life (many mammals, annual plants)
type 2 survivorship
steady decline in numbers (some birds, lizards, turtles)
type 3 survivorship
huge decline in young (invertebrates, perennials)
geometric population growth (examples)
growth in populations where generations don’t overlap (annual plants, insects)
exponential growth (examples)
growth in populations in which generations do overlap (trees, bacteria, humans)
why can’t exponential growth continue forever?
limited resources and harm to environment
logistic growth (sigmoidal curve)
Population grows rapidly, slows, and stops at carrying capacity, K
lotka-volterra model
adds a coefficient to account for the competitive effect of another species (alpha)
interspecific competition: co-existence
no species is competitive enough to drive out the other species
interspecific competition: exclusion
one species completely outcompetes others and leads to exclusion of those species
What is Gause’s Principle / Competitive Exclusion Principle?
Two competing species with with identical ecological requirements cannot occupy the same area
what is the corollary for Gause’s Principle?
if two species co-exist they must have ecological differences
Why can successful invasive exotic species outcompete native species?
lack of natural enemies, high reproductive rate, highly adaptive
what is allelopathy
Production and release of chemical substances that plants release that inhibit growth of other plant species
example of allelopathy
black walnut produces juglone
resource partitioning with competition
interspecific competition narrows range of resource utilization for each species involved
resource partitioning examples
plant roots extend to different regions of soil, farblers eat off different parts of trees
niche definition
The fundamental role of the organism in its community - what it does, how it relates to its food and enemies by charles elton
what is an organism’s hypervolume
an organism’s niche consists of many physical and environmental variables, each can be considered a point in multi-dimensional space, that space is called hypervolume
fundamental niche (potential)
An individual or species free from interference of another could occupy the full hypervolume or range of variables to which it is adapted
realized niche (actual)
Conditions under which an organism actually exists
niche relationships
can be disjunct, overlapping or adjacent
niche overlap leads to ____
competition
what is niche compression?
contraction of habitat resulting from competition, usually one species gets a larger portion of their niche in the overlap
what is ecological release?
niche expansion in response to reduced interspecific competition
what is niche shift
adoption of changed behavioral and feeding patterns by competing populations to reduce competition
what is character displacement?
a long term response to niche shift
predation
killing and consuming of another organism
ecological meaning of predation
transfer of energy/nutrients
the outcome of predator-prey interactions depends on
Reproductive rates of predator and prey, adaptive capacity of predators to respond to increase in prey density, carrying capacity for prey population in the absence of predation
