ecology

Question 1

abiotic vs biotic factors

Answer 1

abiotic= non-living components

biotic=living components eg)plants, animals

Question 2

order of ecologial systems (we looked at 4)

Answer 2

organismal
population
community
ecosystem

Question 3

organismal ecology

Answer 3

smallest scale of ecology

organismal ecology studies an organisms interactions with its abiotic enviornment and other individuals.

close link w evolution as when smthn occurs within the ecological framework of time like an individual falling prey to predator or a plant not setting bc of drought. it can lead to selective pressures that favour some structures and behaivours such as anti-predatory

encompasses: morphology, physiology, behaviour

Question 4

selective pressures

Answer 4

an evolutionary force that causes a particular phenotype to be favoured in certain enviornemntal conditions

Question 5

population ecology

Answer 5

“what enviornmental factors affect the reproductive rate or survival of a particular species?”=population ecology

dynamics of species populations and how these populations interact with the environment, such as birth and death rates, and by immigration and emigration.

eg) “what factors influence the species diversity in a forest or a coral reef?”

Question 6

population vs community

Answer 6

p=all group of individuals of the same species living in the same area at the same time

c=assemblage of all populations of all species living in an area

Question 7

community ecology

Answer 7

interactions between different populations/species.

concerned w roles of interspecific interactions
eg) predation, parasitism, competition. also abiotic factors like disturbance in the area

“what factors influence the species diversity in a forest or a coral reef?”

Question 8

example of organismal ecology

Answer 8

eg) octupus adapted to camoflauge to hide (morphological). they also expel black ink to protect from predators (physiological). some also hide inside coconuts to provide a hard shell for protection when hunting prey (behaivoural).

Question 9

ecosystem ecology

Answer 9

study of energy flow and the cycling of chemicals through the abiotic and biotic comonents of the ecosystem

Ecosystem is all communities in an area and their physical (abiotic) environment.

eg? “what factors influence photosynthetic activity in the forest ecosystem or coral reef ecosystem

Question 10

landscape ecology

Answer 10

study of interactions among ecosystems

Landscape or seascape ecologists are concerned with understanding what controls these exchanges,
and they might ask questions such as to what extent do animals use corridors between habitat
patches, or what is the link between deforestation of hillsides and sedimentation on coral reefs

Question 11

what ecoogical sudy would ask “what enviornmental factors affect the birth rate of locusts?”

Answer 11

population ecology

Question 12

mark and recapture method

Answer 12

N=Mn/m

N=total population
M= # of animal caught day 1 (marked)
n=total frogs caught day 2 (marked and unmarked)
m= # of marked frogs recaught day 2

Question 13

how are individuals distributed

Answer 13

a) clumped- seastars grouped where tehre is food
b) uniform- seagulls mark their breeding territory and stay away
c) random-dandelion seeds getting dispersed by the wind

Question 14

life histories and package A vs. B

Answer 14

refers to the pattern of survival and reproduction events during the life of an organism.

package A:
breed young
breed often
many small babies
small bodies
short life span
little parental care

package B:
breed late
breed rarely
few large babies
large bodies
long life span
long parental care

Question 15

life history tradeoffs

Answer 15

organisms have a certain amount of energy in their lifetime. therefore an organism has to make allocation ‘decisions’ (we say decisions but they are not actual conscious decisions, instead influenced by natural selection)

so if an organism puts more energy towards reproduction, many babies and more frequently, there will be less energy towards growth so shorter life span, smallerbabies. vice versa. maintanence is fixed

-think energy pies split into R (reproduction), G (growth), M (maintanence).

Question 16

exponential growth

Answer 16

-J curve
-accelerating increase in population size when r is constant
-density independent

eg) microorganisms keep growing as long as temp and humidity are favourable

Question 17

logistic growth

Answer 17

-S curve
-decrease in growth rate as carrying capacity is approached
-density dependent
-when carrying capacity is reached r=0 (constant)
-as density of population is low r>0 (growth rate is growing)

Question 18

when does exponential growth usually occur?

Answer 18

when resources are plentiful and not many competitors

Question 19

population dynamics:

Answer 19

-studies how populations change overtime
-simply the sum of gains through birth and immigration (B) and losses through death and emigration (D).
B>D population increases
B<D population decreases
B=D no change

Question 20

interspecific vs intraspecific interactions

Answer 20

intra= efects of interactions between individuals of the same species
inter= effects of interactions between individuals of other species

to study inter we analyze the effect of one species ftiness and the fitness of another species (compare using -,+,0)

Question 21

situations that effect fitness

Answer 21

competition
predation
herbivory
mutualism*
parasitism/disease*
commensalism*

*all examples of symbiotic relationships

Question 22

interspecific competition

Answer 22

(-/-)
interaction between organisms using the same resources
negative effcts: reduced growth, reduced reproduction, local exclusion

eg)plants competing for sunlight. can be shot vs tall plants. tall plants need to invest more energy in growing taller so NO ABSOLUTE WINNER IN ANY BIOLOGICAL COMPETITION

Question 23

wht is competition detrimental to both species

Answer 23

by restricting access to key resources this can lower growth and reproduction. which in turn lowers fitness

eg) microsoft vs apple-have to split customers and both have a loss bc of that.

Question 24

predation and herbivory

Answer 24

+/-
detrimental to prey but beneficial to predator

basis for coevolution

Question 25

coevolution example (Arms race)

Answer 25

moth vs bat
moths developed a warning system like ears that allowed them to hear a bat’s echolocations. bats reacted by improving stealth eholocation (higher frequency to moths) moths combatted by eveolving ulrasonic clicks to hear better

Question 26

symbiosis

Answer 26

close and prolonged relationship between 2 diff species
a) parasitism-harmful to one beneficiary to other (fleas and dogs-fleas get food and habitat from host)
b) mutualism-both benefited (hippo and bird/oxpecker-bird feeds and hippo is cleaned)
c) commensalism-beneficial to one but neutral to other (barnacles on wales)

Question 27

is parasitism and disease considered predation

Answer 27

no bc of size. predation, predator is much larger

Question 28

effects of mutualism on community structure

Answer 28

1. potentially increase species diversity
2. potentially increase distribution range and more

eg)bird feeding on crocs mouth while croc is being cleaned

Question 29

effects of parasitism/disease

Answer 29

1. reduce host survival, host reproduction, host density
2. major effect on r

Question 30

effects of commensalism

Answer 30

difficult to measure so we dont know

eg) cowbirds feeding on buffalo, barnacles getting free rise on whales

Question 31

niche

Answer 31

-the range of resources that a species can use and the range of conditions that it can tolerate
-each species have a diff set of adaptations and so they dont directly compete for all the same resources.
-Two species cannot coexist in a community if they share an identical ecological niche

Question 32

fundamentl niche vs realized niche

Answer 32

f= range of resources that is potentially/theoretically occupied by the species if there was no constraints in any wy

r=portion of fundamental, that is acc being used by species bc theyre contrsinaed by factors like competition

in other words: an area that can be potentially occupied if it were the only species. since the species is on its own it can spread out and enjoy the space and this is the fundamental niche. When there is anotehr species there it cant occupy all of the area and so it actually can only occupy some of it. this is the realized niche. (the niche can be any resource not just space occupied)

Question 33

competitive exclusion

Answer 33

the principle that 2 species cannot coexist in the same ecological niche in the same area bc one species will outcompete the other

outcome=one species will drive out the other

Question 34

niche differentiation

Answer 34

when competing species evolve different niches to avoid competition from niche overlap

outcome: niche differentiation can lead to character displacement

Question 35

character displacement

Answer 35

when species evolve to be different than eachother to reduce interspecific competition due to same niches

character displacement makes niche differentiation possible

Question 36

trophic levels and food chain

Answer 36

t= a feeding level in an ecosystem (organized by numbers)
f= pathway of energy flow

Question 37

food chain levels

Answer 37

secondary consumer- carnivores, consume primary consumer
primary consumer- herbivores, consume primary producer
primary producer- creates own food
decomposer- (detrivores) consum dead organic matter

Question 38

important species

Answer 38

a) dominant species-most abundant (eg. american chestnut)
b) keystone species-exert strong control over distribution eg.wolves in yellowstone
c) ecosystem engineers- exert their influence by changing physical enviornemnt eg. beavers building dams

Question 39

_______ is followed by succesion

Answer 39

ecological disturbance

ecological disturbance is when an event changes a community by removing organisms from it or altering resource availability

Question 40

Ecological succession:

Answer 40

the gradual recovery of a habitat after an enviornemntal disturbance, usually n
Primary succession:
the process of recovery that begins in a virtually lifeless area, SOIL HASNT FORMED YET.
Secondary succession:
gradual colonization of a habitat after a major disturbance that leaves the SOIL INTACT