Ecology

Question 1

considerations for the SLOSS debate of conservation

Answer 1

SLOSS = single large or several small:

• size: bigger better than smaller;
• subdivision - contiguous better than broken up;
• separation: closer together rather than farther apart;
• linearity; globular rathr than linear;
• connection: connected rather than discrete;
• edge/ interior ratio (consider edge effect): lower edge to interior ratio is better

Question 2

Scales of interactions (BLECPO scales)

Answer 2

organism
population
community
ecosystem
landscape
biosphere

Question 3

descriptions of organismal locations

biogeography, biome, habitat

Answer 3

• biogeography - distribution through space and time; abundance and diversity of orgs depends on available resources, especially water;
• biome (not a very helpful term) - usually terrestrial; these include: tropical rainforest, savanna, desert, heathlands, temperate grasslands, temperate broadleadf forest, northern coniferous forest, tundra, high mountains, polar ice
• habitat

Question 4

niche (including fundamental niche and realised niche) AND population dynamics

Answer 4

where an organism lives AND what function it serves in the environment;

• fundamental: the possible distribution of the organism as determined bu its evolutionary history;
• realised niche: the actual distribution of the org, as limited by interactions with other orgs;
• population dynamics: how orgs are utilising their niches (eg abundance / thriving or dwindling)

Question 5

population ecology

Answer 5

accounts for the “life history” of organisms in a particular environment

Question 6

purpose of ecology: solving problems of DISTRIBUTION and ABUNDANCE

Answer 6

distribution: where orgs are found
abundance: what is the population? are there more or less than there should be?

Question 7

biotic and abiotic factors

Answer 7

biotic - between organism interactions

abiotic - including light, water, temperature, etc.

Question 8

climate (macro and micro)

Answer 8

temperature, sunlight, wind and precipitation

• macro: patterns on the global, ecosystem and landscape scales;
• micro: finer scale patterns, eg community of orgs on a tree trunk

Question 9

Hopkins’ bioclimatic law

Answer 9

air cools as it rises

Question 10

bioaccumulation AND biomagnification

Answer 10

bioacc: the increase in chemicals in a single organism over its lifespan or a single trophic level over time;
- biomag: accumulation of chemicals through trophic levels, increasing as you go up through the consumption levels

Question 11

trophic levels AND food web

Answer 11

or “food chains”;
constrained to be about 5 levels long;
-food webs are perhaps more accurate representations of trophic interactions between orgs in an environment

Question 12

production efficiency

Answer 12

the percentage of energy from food source that is used for growth and reproduction, ie keeping energy in the system, as opposed to it being lost as heat along the way

Question 13

ecological efficiency

Answer 13

an organisms production efficiency (see card) as well as how efficiently it uses energy for movement and metabolism;
determines a species’ abundance

Question 14

biomass

Answer 14

factors abundance and mass in conceptualising trophic pyramids

Question 15

biodiversity

Answer 15

the number of species present, limited by the number of available niches;
the variety, distribution and abundance of species in an environment;
measured according to the number of vascular plants

Question 16

island equilibrium theory of biogeography

Answer 16

species diversity on islands will represent a dunamic balance btwn the prob of successful colonisation by immigrant species, and extinction of resident species

Question 17

competitive exclusion

Answer 17

competitive advantage will lead to success for 1 and extinction for the other;
a type of niche division

Question 18

disturbance AND

intermediate disturbance hypothesis

Answer 18

pressures in an environment, eg intro of predators, climate change, etc.
- can be stocastic ie one-off cataclysmic events
- IDH: diversity will be highest when interference prevents competitive exclusion, but is of low enough intensity or frequency to allow many species to prosper;
disturbances can be biotic or abiotic

Question 19

keystone species

Answer 19

those with the highest number of interactions in an ecosys

Question 20

red queen hypothesis

Answer 20

evolutionary arms race’ ie running to stay in the same place;

• occurs between prey and hunter species;
• drives mimickry

Question 21

symbiosis (paracitism, mutualism, commensalism)

also Facilitation

Answer 21

• fac: when species have pos effects on others without direct symbiotic contact

Question 22

biodiversity hotspots

Answer 22

• high diversity of >1500 endemic vascular plant species;

- have lost 70% or more of their original habitat

Question 23

dispersion v. dispersal

Answer 23

dispersion: how members of a species are arranged throughout an environment; can be:
- random
- regular (rare; competitive)
- clumped (common; cooperative)

dispersal: where the offspring go to

Question 24

factors controlling population size (four)

Answer 24

• sources of increase:
  1. birth
  2. immigration
• sources of decrease:
  3. death
  4. emigration

Question 25

growth rate AND intrinsic rate of growth

Answer 25

represented by “r”

calculated by:
b(birth rate) - m (mortality rate)

rmax = intrinsic rate of growth, ie built into the species

Question 26

allee effect

Answer 26

pop density becomes so low that mating ceases

Question 27

vital rates

Answer 27

birth rates (b) ie fecundity
death rates (m) ie survivorship

Question 28

life history traits

Answer 28

these reflect evolutionary adaptations:

• repro strategies:
  
  • number of offspring;
  • level of investment;
• age-specific distribution of repro and mortality:
  
  • age of sexual maturity
  • senescence and death

Question 29

survivorship (3 types)

Answer 29

1. mortality accelerate with age
   - have few young; invest a lot of time and energy
2. constant mortality rate
3. mortality decelerates over time
   - orgs with lots of offspring that getting bigger and more robust through time

Question 30

levels of parental care (precocial and altricial)

Answer 30

altricial - dependant; weak

precocial: strong, independent

Question 31

semelparity AND iteroparity

Answer 31

semel: one-shot reproduction; multiple young; maybe short lifespan
itero: many chances for repro; 1 or few young each time; over many years