Ecology Flashcards
Scale of Ecology
organismal population community ecosystems landscapes global/macro
Reasons for distribution of biodiversity
climate created by tilt of earth and wind cells
Coriolis effect
creates major trade winds and oceanic current
result of equator moving faster than the poles.
Effects of earth’s tilt
seasons
create wet and dry seasons
changes wind patterns which changes ocean currents
effect of mountains on climate
wayward side is wet because of moist air coming off water and cooling as it goes up mountain
air on leeward side is very dry, creates deserts
define microclimate and give two examples
local zone where climate differs from surrounding area
- In winter, under snow. Stable temperature, some plants grow and animals around to eat them-called subnivium ecosystem
- Koala bears live in eucalyptus trees because they are cooler than the surrounding environment.
Effects of global climate change on species’ range
- extinction
* *golden toad in costa rica killed by tropical fungus that thrives in warmer climate** - exterpation: loss of some populations not whole species because species cannot survive at certain temperatures/climates.
- expanded range: species have moved towards poles and up mountains.
- No-analog communities: populations that previously were not in contact are now because of shifting ranges.
Net Primary Productivity (NPP)
production of organic compounds from atmospheric or oceanic CO2 by autotrophs.
amount of new biomass added to in a given period of time. tropical rainforests most productive
Biodiversity
species richness/number of species
variation of living world from genetic diversity to diversity of species in an ecosystem/biome
tropical rain forest
located at equator
+B
+NPP
Desert
North and south of tropics
+B
-NPP
dry
Savannah
ecotone between rain forest and deserts
grasslands
center of large landmasses
subject to large climate swings because not stabilized by any body of water
rest by fires
inhabited by large mammals because need large digestive systems to digest grasses.
mid B and NPP
chapparel
on coasts otherwise would be desert because located north/south of tropical rainforests warm and moist because of ocean currents hot and dry seasons moderate NPP -B fire adapted species
northern coniferous forests
north america, europe and asia
short growing season
+NPP few species able to live there are large and can fix a lot of CO2
-B b/c few species adapted to live there
temperate deciduous forests
located on coasts primarily because of ocean currents that bring warm moist air
long growing season
lots of temperature variation and high precipitation year round
+NPP
moderate B
tundra
at extreme latitudes
cold dry short growing season (if any)
-NPP and -B
Anthromes
human-created biomes
NPP decreases towards dense settlements
native species also decline in that direction but ornamental/non-native species increase
Biodiveristy may increase because of imports
ocean pelagic zone
low NPP (carbon sink)
-B
huge expanse but not full of life of productivity
abyssal zone
hydrothermal vents \+B average NPP located around plate edges have chemocynthetic bacteria that use sulfur for nutrients
coral reefs and kelp forests
shallow marine biome along equator
+B and +NPP
very small biome but highly productive
created because of ocean currents
estuaries/salt marshes/mangrove forests
-B and +NPP because of tidals swings. organisms fed by nutrients coming from water but need to be adapted to water and air exposure
lentic systems
still terestrial waters
lakes and wetlands
oligotrophic
-B and -NPP
deep water, cold, clear water
light cannot reach ottom in most places
lake superior
eutrophic
+B and +NPP
shallow warm nutrient rich murky water
lake medota
light penatrates to bottom stimulating growth
wetlands
extreme eutrophic lake
water covers part of year and has water rich soils and water loving soils
+B and +NPP because so shallow
marshes, swamps, bogs
lotic systems zones
running water systems
- headwaters=-B and -NPP. high course particulate matter, cold, narrow, oligotrophic
- mid-regions: water slows and warms, course particulates broken down, primary producers, +B and +NPP
- lower regions: low course particulate count, cloudy water, moderate B and NPP
Latitudinal Diversity Gradient (LDG)
increase in species diversity going from poles to tropics
120 hypotheses exist
Biome productivity/energy hypothesis
amount of energy in biome drives diversity
but NPP and B are not directly related (deserts)
Biome size/area hypothesis
bigger land masses have more species, more productivity
but largest land biome is desert yes +B but -NPP
climate stability and predictability of biome
tropics do not vary much in temperature or precipitation
but still flawed in some way
age of biome
biomes destroyed by glaciers and must restart
tropics ancient so have lots of species but flawed in a way we don’t need to know apparently
Grographic area/mid-domain effect
null hypothesis
random chance
Animal Behavior
combined with animal physiology leads to all levels of ecological science
gives insight into mechanisms behind population and community ecology
Behavioral ecology
study of othology (animal behavior) focusing on ecological and evolutionary implications of animal behavior
Innate behavior
developmentally fixed.
shared by all members regardless of individual preference and environmental differences
learned behavior
modified based on previous experiences
mixed behavior
bahavior is innate but skill is learned
example: birdsong
Fixed Action Pattern (FAP)
innate behavior that is indivisible and runs to completion regardless
ex: when brood parasites lay eggs in different nest, other bird still feeds chicks because that is what the innate behavior is even though the chick is clearly not its own
Movement-Taxis
innate response to directional stimulus/gradient
not a tropism because animal has mobility
example: trout always face upstream so they don’t get swept away
Movement-kinesis
innate response to non-directional stimulus
orthokinesis
speed of movement is dependent upon intensity of stimulus
example: prey runs faster when predators around
Klinokinesis
sinuosity of movement is proportional to stimulus intensity
example: baby turtles usually follow straight path towards ocean when they hatch. Light makes them vear off course–worse at higher intensities of light
Signals and communication
signals: stimulus transmitted from one organism to another
comm: transmission and reception of signals
example: one bee finds a food source and relates it to others with dance that tells direction and distance from hive
thermocline
layers of lake
Summer: warm on top, denser cold on bottom
Fall: turnover b/c top cooling
Winter: top frozen then cold then warm at bottom
Spring: turnover as top melts and warms
Imprinting
phase sensitive learning
rapid and independent of consequences
Filial Imprinting
babies learn from parents.
can be taken advantage of like to teach birds to migrate
Spatial learning
there is strong selective pressure to estimable memory that reflects spatial distribution of resources
ex: wasps use landmarks to memorize location of nest
Path integration (ded reckoning)
animals can continuously compute location from past trajectory and efficiently return to starting location
useful in featureless landscapes
cognitive map
internal representation of lanscape
held in brain and allows for visualization of map to make useful path
Associative learning
association of stimulus with another
classical conditioning
arbitrary stimulus associated with a particular outcome
operant conditioning
animal first learns to associate a behavior with a reward or punishment and then tends to repeat or avoid behavior
“trial and error” learning
cognitive learning
knowing that involves awareness, reasoning, recollection, and judgement
social learning
examples:
1. prarie dogs have different calls for different situations. animals from other populations can still recognize signs.
2. Birdsong: birds partner with tutors to learn how to call well
Factors effecting biome distribution besides geography and climate
- soil type
- available nutrients
- space
- seed source
- competition
though wisconsin is fully in temperate zone, why is vegetation different in north than in south?
In north it is colder so there is more water (less evaporation and transpiration)
differences in soil, elevation, and proximity to streams also effects vegetation
Foraging ecology
food obtaining behavior including diet and activities used to search, recognize, capture, and consume food
Optimal foraging
animal is able to obtain best food resource with least amount of costs
Reproductive ecology
behavior leading to the creation of offspring, including all activities that animals use to seek, identify, and compete for a mate
Infanticide
killing of infants by mature adult of same species
Benefits: ensures murderer’s genes are passed on
affects how mother bears feed and how females mate (with lots of men for paternal confusion)
Interspecific foraging risks
behavior of prey affected by presence of predators
ghosts of predators past hypothesis
animals that were prey previously retain evasive behavior in absence of predator
relatively hard-wired traits
how foragers avoid predators
camouflage
change activities like activity period or avoid kill zones
be dispersed or be densely packed
How foragers avoid death once found
be fast
taste bad and show that
increase handling time with hard outsides
Predator Functional Responses types
Type I: kill rate is proportional to prey density (spider web eventually reaches capacity regardless of how high the fly population gets)
II: kill rate is limited at high prey density because of handling time (professor eating snickers is slowed down by wrappers)
III: kill rate is limited at very low prey density (absence of search image), accelerated at moderate density and slowed at high density
Predator Functional Responses definition
behavioral response to predator based on abundance of prey
number of prey eaten per predator relative to amount of prey on landscape is how it is graphed
Monogamy
evolved because of limited resources and a need for both parents to rear and search for food.
example: Wandering Albatros
90% all birds monogamous because females too spread/free for a male to control many.
Cuckolding
in monogamy female mates with other males and her single partner still raises the offspring
may lead to decrease in parental investment in rearing
Resource defense polygyny
male defends resource to attract as many mates as possible
red winged black bird set up a territory and aggressively protect it
mate gaurding polygyny
resources is not defensible to males compete for the opportunity to mate by actively guarding females
porcupines: females spread over wide area so males travel around and mate when females in heat then stay until she is out of it then move on to next female
Lek polygyny
resources are not defensible so males compete by attracting attention with dances, songs
example: sage grouse
sperm competition
by means of repeated copulation, mating plugs, and others, male is able to ensure his sperm is successful in fertilizing
cooperative polyandry
several males defend a female territory
resource defense polyandry
females defend territories that contain smaller areas of groups of males
benefits of polyandry
sperm replenishment (a man is always available) material benefits genetic benefits (females have options to chose fittest) female convenience (does not need to look for a mate)
promiscuity
individuals are not territorial so there is lots of overlap and things mate through random encounter
example: two-toed sloth
Operational Sex Ratio
ratio of females:males
explains mating system
polygyny: more females than males
monogamy: equal ratio
Sexual size dimorphism
male size:female size
polygyny: males larger
monogamy: equal size
females and males may have totally different diets due to differences in size
population definition
group of organisms of same species occupying same space at a particular time
Dispersion
use quadrants to determine type
null hypothesis: dispersion is random
Poisson dispersions
random: mean=variance
clumped: meanvariance
Indicies
index of density is any measurable correlation of density. usually a count statistic that is obtained in the field like number of nests then just need to convert that to number of individuals.
can be biased based on ease of seeing things and whatever
Mark-recapture equation/Lincoln-Peterson Equation
(marked and recaptured, r) ===(total captured first time, m)
———————————– ———————————
(total captured 2nd time, c) (population size, N)
Mark recapture issues
if animals cage shy after being captures first time, r is small and N will be too large
if animals cage happy after capture, r r is large and N is falsely small
Assumptions of Lincoln Peterson equation
- equal probability of capturing and recapturing all animals
- complete mixture of population after release
- closed population (no immigration, emigration, birth, death)
Exponential Population growth equation and uses
dN/dt=rN r=rate of growth and N=starting population
- when invading/colonizing new place
- rebounding from massive crash
- when a new adaptation develops to cope
- at start of bounded population
Density Dependence
decline in population growth rate as population increases because of competition for resources and space
Carry capacity invovlement
k/2=time of greatest increase in population growth
assumptions of exponential growth model
constant birth and death rate
no immigration or emigration
no time lags
there are enough resources and space for all organisms to survive as the population grows
Positive Density Dependence/Allee Effect
population growth rate is low when population size is small because of low reproductive success/survival
- can’t find each other to mate
- so on dN/dt to pop. size graph, before fast increase, a dip.
example: ferrets
assumptions of logistic growth
constant birth and death rate
no immigration, emigration
no lag time
environment is constant except for crowding effect (reason for carrying capacity)
effect of crowding is felt by all, equally
does not consider unpredictable variation in weather, etc
deterministic growth models
outcome determined only by inputs.
nothing is left to chance or changing conditions
stochastic models
account for less predictable changes in and uncertainty around growth rates that alter population factors
example: chaparrals burn down ~1/decade
Environmental stochasticity
annual changes in population because of weather, food supply, etc
Catastrophic stocasticity
fire, flood, droughts that occur occasionally and impact the majority of the population
Demographic stocasticity
natural and unpredictable fluctuations in birth and death rate and sex ratios
patterns of mortality
Type III: death of most in early years. Few live to old age
II: likelihood of death equal for all age groups
I: majority live to old age then die quickly
does not consider differences in male and female survival
Hypotheses for differences in male and female mortality timelines
H1: chromosomal
- reproductive/dispersal
- intraspecific competition
metapopulation
assemblage of local populations connected by emigration and immigration. matrixes (areas of passage only)
Classic metapopulations
b, d, i, e vary between local populations
dispersal can repopulate dying or extinct local populations
source-sink metapopulations
one big population with greater birth than death rate (source) disperses out to inferior habitats where death is greater than birth rates (sink)
patchy metapopulations
variable b d i e. emigration and immigration are so high that demographic differences between local populations are insignificant and populations are not independent of each other
Island metapopulations
immigration and emigration are functionally zero so subpopulations are independent and dispersal is not sufficient to repopulation dying or extinct populations.
Island biogeography
number of species on an island reflects balance between rate of new-species colonization and rate of existent-population extinction
Exploitation competition
using up a resource
example: the more prairie dogs on a landscape the less weight gained by cattle
Interference competition
behavioral interactions that keep other from gaining access
example: interspecific killing NOT for food.
preemptive competition
individuals use space that is then unavailable to others
Gause’s Competition Exclusion Principle
two species that have the same niche one will go extinct
Fundamental niche
niche occupied in absence of predators
realized niche
niche occupied in presence of predator
Niche separation
species should be under selection to evolve to use different niches with lower overlap BUT overlap still exists because efficient use of resources drives organisms to stay close.
Types of predation
- herbivory
- insect parasitoids
- parasites
- cannibalism
- classic predation
herbivory
eating plants
monophagy (one plant)
polyphagy (lots of plants)
rare in birds because lots of digestive parts needed
insect parasitoids
insects that lay eggs on or near host that then consumes the larvae.
somewhat specialized at least
always kill the host
example: wasps
cannibalism
consuming conspecies.
rare because of disease transfer and eating own species bad for population size
Why care about predation
mechanism of natural selection
determines cost-benefit balance in sexual selection (guppies)
life history breeding (age of breeding, nesting strategies)
anti-predation adaptations
Character release
when animal is in environment without competitors it is able to occupy a broader niche.
Character displacement
a species that previously had no competitors gets a competitor and it develops a more restricted characteristic because of niche partitioning.
Difference between phenotypic plasticity and character displacement
phenotype changes because of changing environmental conditions. It does not change the genotype of the species. Character displacement is a result of natural selection/evolution
keystone predator
removes some of the more competitive species from an ecosystem freeing up niche space for more species.
areas with keystone predators have greater species richness
first law of thermodynamics applied to ecology
energy amount constant. plants convert solar energy to chemical. some lost as heat.
second law
in energy transfer if no energy enters or leaves system, potential energy will always be less than at the start because of heat loss
Why are predators larger than prey?
In aquatics, predators must engulf prey or else it could get swept down stream.
On land, do not need to be as large because they have the ground to hold dead animal.
Advantageous to be smaller than prey for some because of stealth and speed.
Aquatic food chains vs terrestrial ones
aquatic can have up to 7 transfers because of more efficient transfer of energy. Terrestrial only 4 at most
Trophic cascade
reciprocal predator-prey effect that alters abundance, biomass, productivity of a trophic level across more than one link in a food web.
Example: sea otter/kelp forest population decreasing because great whale population reduction.
Global cycles
nitrogen carbon oxygen sulfur
because gases
local cycles
Phorphorus, potassium, calcium
because to heavy to travel as gas go by dust
water cycle
in dynamic equilibrium
input=outputs
carbon cycle
out of balance
outputs>inputs because of fossil fuel burning
ocean acidification
result of excess carbon dioxide forming HCO3-. Increases H+ concentration
shells dissolve
