Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Organisms and Environment > Populations > Flashcards

Populations Flashcards

1
Q

Ecology

A

Scientific distribution and abundance of organisms and interactions that determine these and biodiversity => individual, population, community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Ecological niche

A

Sum of total adaptations of an organismic unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Niche

A

Role of an organisms in its community (not out competed). Includes: foraging strategies, diet, reproductive strategies, social organisation, predators, environment tolerances, morphology, sense adaptations, physiology, competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Life zones depend on

A

Humidity and ppt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Charles Elton 1927

A

A niche is a place in an environment, with relations to food and enemies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cause 1934

A

Competition, 2 similar species scarcely occupy similar niches - certain peculiar types of food etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Competitive exclusion principle

A

Complete competitors cannot exists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Niche segeration

A

Higher species richness = higher efficiency of conservation costs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hutchinson’s model fall backs:

A

Not all niches environmental, some behavioural
Not all axes linear
Different species can hold similar niches - same species different niches
Once a niche is vacant, other organisms can fill the position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Fundamental niche

A

Entire set of conditions under which a species can survive and reproduce => larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Realised niche

A

Set of conditions actually used by species after interactions with other species are taken into account => different locations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Specialist niches

A

Smaller niches than generalists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Levin’s measure of niche breath

A

B = 1/ total (pi^2)
Pi = probability of individuals that use resource i or probability of diet consisting of i
Niche breath is important so that there is no niche overlap
There is a constant niche breadth
But we do not know how many individuals are in the niche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Niche overlap

A

Coexistence, including overlapping => hyperspace, reciprocal overlap, asymmetric overlap (pushed out original niche), non-overlapping: abutting, disjunct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Classification of non-overlapping niches

A

Resource limiting => competition currently occurring, abutting niches indirect indication => niche divergence (competition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Niche partitioning

A

Narrow niche - coexists with other species -> more specific. Wide niche - single species on island

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Competitive release

A

Take out one species, another may expand its niche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explanations for different niches

A

Competition, evolutionary competition avoidance, (Connell 1980 ‘ghost of competition past’ - competition most = red - breeding success, natural selection eliminates niches more distinct from completion spectrum), evolution in response to natural selection - independent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Population

A

A group of interbreeding individuals in a given area at a given time
Number of individuals, population density/area, BR + DR id randomly distributed, or mobile = single density. Not all individuals in the population are the same => structured population (age or stage-structured)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Individual

A

Unitary species - zygote (sexual reproduction) => eugenically unique organism
Modular - zygote => similar modules - expand, new individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Genet

A

Individual from SR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Ramet

A

Module reproduces AS by genet (same genotype)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Population distribution

A

Spatial location of individual - stationary (sessile) or vary (migration). If movement between groups of individuals is less frequent = local populations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Metrapopulations

A

Sub-populations linked by dispersal, groups of populations connect by immigration an emigration => larger regional population. Key premises: local breeding and migration

25
Q

Life tables

A

Summarise/infer patterns or B and D => overtime follows cohort and record structure at some point in time

26
Q

Age-sructrured census

A

Census at single point in time. Multiple can reveal important events over time=> infer multiple cohort dynamics.

27
Q

Nt+1 =

A

Nt + Br - Dr + It - Et
Nt = number of individuals at time t, Br/DR between time t and t+1
It = number individuals immigrating t - t+1
Et = number individuals emigrating t - t+1

28
Q

Why do we estimate populations

A

To manage ans conserve species and understand BR/DR

Total individual counts, or sampling methods, estimate relative density e.g. facial pellets

29
Q

Model of populations, N(t) =

A

N(o) x e^rt

r = intrinsic rate of geometric population increase

30
Q

Population regulation - dN/dt

A

Stabilises populations and stops exponential growth
dN/dt = r (1 - N/k) v
K = population carrying capacity (max)
N = population size
Higher N = closer to k
N is small => dN/dt = rN (exponential growth)
N = k/2 => growth rate is highest
dN/dt very small = population size levels off
dN/dt neg => population declines to k

31
Q

Interspecific reactions: Competition

A

-/- use same resources and insufficient to supply the combination of needs

32
Q

Interspecific reactions: Predation

A

+/- one organism consumes all or part of another, also herbivory and cannibalism

33
Q

Interspecific reactions: Paratism

A

+/- Close association with hosts - feed on (don’t always kill) => micro parasites multiply within host survive, macrparasites grown in/on host, don’t multiply

34
Q

Interspecific reactions: Amensalism

A

-/0 e.g. large mammals 0, plants near waterhole -

35
Q

Interspecific reactions: Comensalism

A

+/0 e.g. egret cattle capture more insects when with large animals - egret +, buffalo 0

36
Q

Interspecific reactions: Mutualism

A

+/+ both individuals benefit => facultative pollinations, seed dispersal, permanently paired, at least 1 cannot live independently (obligate)

37
Q

Predation and population change

A

Predator/prey cycles e.g. low red = inc in prey = inc in red = dec in prey = dec in pred

38
Q

Gross primary productivity

A

Rate energy is incorporated into bodies of photosynthetic organisms (5% solar energy)

39
Q

Gross primary production

A

Amount of accumulated energy (metabolic, growth, reproduction)

40
Q

Net primary production

A

Energy available to primary consumers

41
Q

How does temperate and moisture affect biomass?

A

Warm air = more evaporation and transportation rates
Low temps = low photosynthesis and low production
NPP at equator = high m ++ = high NPP
Decrease in ppt and temp = decrease in biomass

42
Q

Trophic levels

A

Divided on how energy is obtained

43
Q

Assimilation efficiency

A

Assimilation: ingestion (I) => A + Expelled

44
Q

Production efficiency

A

Production: assimilation A => respiratory + P

45
Q

Detritivores

A

Eat dead and water

46
Q

Omnivores

A

pp and another trophic level

47
Q

Energy available to given trophic level

A

Productivity of next lower level (n-1)

48
Q

Consumption efficiency

A

Ingestion: production (ln/Pn-1)

49
Q

Food chain

A

Sequence of interaction => feeding - short, energetic

50
Q

Food web

A

Interconnected food chains. Apex predator - no predators itself

51
Q

Keystone species

A

Strong influence on ecosystem but low abundance

52
Q

Trophic cascade

A

Change in species community at 1 trophic level affects species community at trophic level not directly above or below e.g. predators reduce herbivores = increase in plant biomass

53
Q

Community importance for a species, Clx

A

Species lost during the removal of species X
= ((tN - td)/tN)/Px
tN = quantitative measure of community trait in intact community
td = quantitative measure of community trait after species x removed
px = proportional abundance of species x before removal

54
Q

Community stability

A

Equilibrium model
Most natural comms on a continue stable => unstable
Measured as time to recovery from disturbance or variability of comm over time

55
Q

Stable community

A

Many interactions (competition and predation), processes operate in a density dependent manner to regulate population sizes, species saturation rare, catastrophic environmental events

56
Q

Local stability

A

Environmental changes, communities replaced

57
Q

Global stability

A

Maintains itself

58
Q

Food web generalisations

A

More species = more linkages, chain lengths short, proportion of species at each level approx constant, omnivory common

59
Q

How can you study food webs using stable isotopes?

A

Ratio of isotopes expressed as theta values (parts per 1000). On average thetaN increases by 3.4% in animals relative to their diet => separate animals from different trophic levels. Bioaccumulation.

Organisms and Environment (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions