Mid text Flashcards
define ecology
the scientific study of relationships between organisms and their environment
define Resources
consumed by an organism
define conditions
influence an organism but are not consumed
define hazard
include factors that can only affect an organism negatively
ex: substances(DDT)
Events(natural disasters)
Who coined the term Ecology?
Ernst Haeckel
Ecosystem?
Units of nature in which organisms interact with each other and with their surroundings
Ecological Hierarchy?7
Individual-Population-community-Ecosystem-Landscape-Biome-Biosphere
population?
is a group of individuals of the same species occupying a given area at a given time
community?
collectively, all populations of all species lving and interacting within an ecosystem
Landscape?
an area of land(or water;seascape if marine) composed of a patchwork of ecosystems
-ecosystems linked by dispersal of organisms and exchange of materials & energy.
Biome?
Broad-scale regions in which landscape is dominated by similar ecosystems.
Biosphere? Global Abiotic spheres?
the narrow interface at Earths surface that contains and supports life.
-Including Global Abiotic spheres: Atmosphere, Hydrosphere, and lithosphere(solid ground and soil)
Fitness?
the relative number of offspring that survive to reproduce
Asexual Reproduction(4)
offspring are always genetically identical clones of the parent.
Binary Fission: (Paramecium) simply splitting in half
Budding: (Freshwater Hydras) a bud pinches off as a new individual.
Parthenogenesis:(Wingless female aphids)(Crayfish)(Komodo Dragon) ovum develops into an organism without fertilization.
Plants: Stolons, rhizomes, apoximosis(type of parthenogenesis)
Budding?
Asexual reproduction where a bud pinches off as a new individual: Freshwater Hydras
Parthenogenesis?
Asexual Repro where the ovum develops into an organism without fertilization.
Wingless female aphids, Crayfish, Komodo Dragon.
Binary Fission?
Asexual repro simply splitting in half: Paramecium
Apomictic Plants?
Produce more but smaller seeds
Good and Bad about Asexual reproduction?
Allows rapid population growth yet little to no genetic variability
Dioecious?
Unisexual Plants
Hermaphroditic Plants?
2 ways
- ) Bisexual(perfect) flowers with both male(stamen) and female(carpels) organs ex: Lillies
- ) Monoecious: with separate male and female flowers on the same plant(Imperfect because non matching flowers like Dioecious) ex: Birch
Simultaneous Hermaphrodites?
Mating occurs for both parties in both female and male ways.
Stamen?
Plant male reproductive organ
Carpels?
Plant female reproductive organ.
Monoecious?
Plant with separate male and female flowers on the same plant. ex: birch.
Sequential Hermaphrodites?
Molluscs in gastropoda(snails and slugs) and Bivalvia(clams and mussels)= undergo sex change as they grow larger,typically changing from male to female. unbalanced population ratio may stimulate sex change(parrot fish).
Jack-in-the-pulpit(plant) may produce male flowers one year, asexual the next, and then female flowers. The high cost of creating female flowers necessitates this change.
Outcrossing?
pollen from one individual fertilizes the egg of another.
Autogamy?
self-fertilization, an extreme of inbreeding.
Monogamy?
involving a pair bond between one male and female.
extra-pair copulation can occur with both members seeking one other mate each.
Polygamy(2 forms)
- Polyandry-severall males(sand-pipers)
2. polygyny-severall females
sexual dimorphism
why males and females of a different species differ in size, colour, and ornamentation.
Intrasexual selection
male to male or female to female competition for mates
Intersexual selection
typically involves differential attractiveness of one sex to the other.
assortative mating
the female selects a mate based upon specific phenotypic traits.
Coevolutionary arms-race?
some species have intersexual conflict in which the female will resist and must be forced into copulation. So the armsrace begins where the males and females fight the gain the uperhand in either mating or not. EX: Waterstriders.
males aggregate in groups on communal courtship arena’s or ______?
leks
Reproductive Investment?
includes costs of care and nourishment as well as costs of producing offspring.
altricial?
their young are born or hatched in a helpless condition and require much parental care.
precocial?
young have longer gestation period so they are at a more advanced stage.
semelparity
an organism sacrifices future prospects by concentrating its energy on one suicidal reproductive act.
Iteroparity?
the strategy where an organism has repeated reproduction events over its lifetime.
niche gestalt?
describes vegetation profile associated with the breeding territory of a species.
Trillium Cernum?
releases seeds with oil rich bodies attached called elaiosomes. This acts as a bribe to and to drag the seeds underground so that they have a good chance of success.
Modular organism?
develops into a unit of construction which unlike a unitary organism becomes many repeated modules adding on leafs and buds throughout its lifetime to active growth spots called meristems. May have asexual shoots or suckers that may be attached or live independently.
Genet?
is a genetically distinct, free living organism that arises from a fertilized egg.
Ramet?
is a module that is produced asexually by a genet and is capable of independent existence. Whether attached or not the Ramet is genetically identical to their Genet.
Why does modularity complicate population study?
because there are 2 levels of population structure.
- ) the genetic individual(genet)
- ) the module(ramet)
Name 8 different population scales?
- Worldwide
- continental
- Region
- Physiographic area
- cluster
- locality
- colony
- clump
Metapopulation?
the collective of subpopulations
Abundance reflects 2 factors:
- the area over which a population occurs
2. population density
quadrats?
sampling units that are generally square and vary in size.
Mark-Recapture?
Sampling method which involves capturing, counting and recapturing to create a population estimate.
N(population)= n(captured in 2nd attempt) X M(known number of animals) / R(recaptured animals)
Abundance-Indices?
cannot estimate absolute abundance, but a series of values collected from the same area over many years reveals abundance trends.
Populations have 3 ecologically important age classes?
- pre-productive
- reproductive
- post-reproductive
Age class distribution in plants?2
- Establishing populations have many saplings but few larger individuals, as in a balsam fur population on the shore of lake superior in Ontario.
- Mature populations are dominated by mature trees that inhibit seedling establishment and sapling growth, as in oak. These trees dominate until there deaths.
intrinsic rate of increase?
r, instantaneous per capita growth rate
r=0
no population change
r<0
population declines
r>0
population increases
Reindeer
Exponential Growth example: 4 males and 22 females introduced in 1911 to the island of St.Paul in Alaska, By 1940’s, its numbers had grown to over 2000.
Trumpeter Swan
Exponential Growth example: largest bird in N.A, re-introduced 3722 in 1968, 23647 by 2000.
Geometric Model?
instead of exponential model
- describes growth over discrete time intervals(often a year), whereas an exponential model uses a continuous time axis.
Life Table?
quantifies mortality and survival in different age classes(cohorts) of a population.
Cohort?
Group of individuals born at the same time
Life Table explained
x= nx= lx= dx= qx=
X=Age class In years
nx= number on individuals from original cohort that are alive at the beginning of a specified age class(x).
lx= Survivorship value, the probability at birth of an individual surviving to any given age.
dx= the number dying during that time interval
qx= age-specific mortality rate, the number of individuals that died during any given time interval(dx) divided by the number alive at the beginning of that interval(nx).
Dynamic Life table
Regular grey squirrel one cohort
dynamic composite(time specific) life table
based on individuals born over several periods
ex: 2009-2011
2 Most common graphs of life tables are?
- Mortality Curve(qx)
- age specific mortality rates(qx), age class or developmental stage
- Not usually log-scale - survivorship curve(lx)
- Usually Log-scale
- lx on y-axis, time or age class(x) on x-axis
Plant mortality curves assume various patterns, depending partly on whether the plant is ____ or _____.
Annual, Perennial
Survivorship curves?3
- When most individuals live out their life span, survivorship is high over most of their lives, with heavy mortality at the end. Strongly Convex(ex: mammals including humans.
- If survivorship stays constant with age, the relationship is linear. (Ex: adult birds, rodents, some reptiles, and some herbaceous perennials.
- If mortality is high in early life the curve is concave. Most common in nature; most individuals don’t survive past first age class, yet those who do have low mortality rate after.(ex: fish, invertebrates, and many plants, including most trees.)
What is the most common Survivorship curve in nature?
Type 3: If mortality is high in early life the curve is concave. Most common in nature; most individuals don’t survive past first age class, yet those who do have low mortality rate after.(ex: fish, invertebrates, and many plants, including most trees.)
Which Survivorship curve do humans fall Under?
- When most individuals live out their life span, survivorship is high over most of their lives, with heavy mortality at the end. Strongly Convex(ex: mammals including humans.
Crude Birth rate?
number of births in a time interval for every 1000 individuals in a population
age-and sex-specific birthrate(bx)
mean number of females born to a female in particular age group
gross reproductive rate
the mean number of females born to a female over her lifetime, assuming all females survive to maximum age.
net reproductive rate(R0)
the mean number of females born to a female over her lifetime, taking the probability of a female surviving to a specific age into account.
Estimated using fecundity table
To adjust for mortality, we multiply bx values by the corresponding lx values for each age class. The resulting value of lxbx gives the mean number of females born in each age class, adjusted for survivorship.
Values of lxbx are summed over all reproductive ages to estimate net reproductive rate.
fecundity table
lx=
bx=
lxbx=
R0=
incorporates the survivorship column(lx), from the life table along with the age-and sex-specific birthrates(bx).
To adjust for mortality, we multiply bx values by the corresponding lx values for each age class. The resulting value of lxbx gives the mean number of females born in each age class, adjusted for survivorship.
Values of lxbx are summed over all reproductive ages to estimate net reproductive rate(R0).
R0(zero)
net reproductive rate
a population with a stationary age structure has a net reproductive rate(R0) equal to____.
1
generation time(Tc) equation + definition?
the mean time between a female being born and reproducing.
summing lengths of time to reproduction for the entire cohort, devided by the total offspring=
Tc= x(lxbx)/sum of lxbx
logistic growth
S-shaped model= As population density increases, interactions occur among its members-interactions that may regulate growth.
The exponential growth model assumes two things?
- ) essential resources are unlimited
2. ) the environment is constant, with no seasonal or annual variations that might influence birth and or death.
demographic stochasticity
Random year-to-year variation in birth and death rates due to factors intrinsic to the population
Environmental Stochasticity
random variation in extrinsic factors such as temperature, precipitation, and disturbances such as fire and drought.
Resilience?
Measure of Resilience?
the rate at which it returns to an equilibrium level after a disturbance.
Return rate= the time required for the population to establish equilibrium size.
Resistance
the tendency to remain unchanged(maintain equilibrium) when faced by disturbance.
r-strategists have ___ resilience.
Options: High, Low, Medium
high
Population Cycles(oscillations)
Fluctuations that are more regular then we would expect by chance
Stable limit cycle
population size fluctuates around K in a regular manner between upper and lower limits.
Damped Oscillations
where fluctuations decrease over time.
(1) the bottom-up model
(2) the top-down model
(3) the social behavioural model
(1) wherein food availability is the major driver
(2) in which predation and disease(including parasites) are primarily responsible.
(3) in which oscillations are attributed to interactions such as aggressive territorial behaviour and infanticide.
Explain Logistic growth
Logistic growth of a population slows as it nears its carrying capacity. In response to limits imposed by the environment, negative feedback curtails population increase. Intraspecific(within species) interactions among individuals, including competition and social behaviour.
Intraspecific Interactions(2 types)
(within species) interactions among individuals, including competition and social behaviour. Density dependant meaning their effect varies with population size, intensifying as population reaches K
Scramble & Contest Competition
Interspecific
(between species) interactions such as competition, predation, and mutualism can also be density dependant and may also play a role in regulating populations.