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Principles Of Ecology > Final Exam > Flashcards

Final Exam Flashcards

1
Q

Competition

A

An interaction between individuals in which each is harmed by their shared use of a limiting resource.

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2
Q

Interspecific competition

A

Interaction between individuals of different species

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3
Q

Intraspecific competition:

A

Between individuals of a single species.

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4
Q

Competition for Resources

A

Competition occurs between species that share the use of a resource that limits the growth, survival, or reproduction of each species.

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5
Q

Resources

A

are features of the environment required for growth, survival, or reproduction, and which can be consumed to the point of depletion.

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6
Q

Exploitation competition

A

Species compete indirectly: Individuals reduce the availability of a resource as they use it (= Scramble).

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7
Q

Interference competition

A

Species compete directly for access to a resource (= Contest). Individuals may perform antagonistic actions
Examples: when two predators fight over a prey

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8
Q

natural experiment

A

is a situation in nature that is similar in effect to a controlled removal experiment.

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9
Q

Competitive Exclusion

A
  • Competing species are more likely to coexist when they use resources in different ways.
  • If the ecological niches of competing species are very similar, the superior competitor may drive the other species to extinction
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10
Q

Resource partitioning

A

Species using a limited resource in different ways.

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11
Q

α & β

A

competition coefficients

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12
Q

Equilibrium densities =

A

Isoclines –> dN / dt = 0

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13
Q

How can we model competition?

A

Lotka-Volterra competition models

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14
Q

N1

A

population density of species 1.

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15
Q

r1

A

intrinsic rate of increase of species 1.

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16
Q

K1

A

carrying capacity of species 1.

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17
Q

α and β

A

competition coefficients—constants that describe effect of one species on the other.

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18
Q

Zero population growth isoclines

A
  • The population does not increase or decrease in size for any combination of N1 and N2 that lies on these lines.
  • Zero growth isoclines can determine the conditions under which each species will increase or decrease.
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19
Q

Presence of herbivores can lead to

A

competitive reversals.

ie) In the absence of the flea beetles, ragwort is a superior competitor

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20
Q

fugitive species

A

must disperse from one place to another as conditions change.

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21
Q

Altering the Outcome of Competition

A

Disturbances such as fires or storms can kill or damage some individuals, while creating opportunities for others.

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22
Q

Competition can cause

A

evolutionary change, and evolution can alter the outcome of competition

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23
Q

Natural selection can

A

influence the morphology of competing species and result in character
-phenotypes of competing species become more different over time.

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24
Q

Hypotheses to explain changes in hare

birth and survival rates: 1

A 
1. Food supplies become limiting when
hare population density is high, but…
• some declining hare populations do not
lack food
• experimental addition of food does not
prevent decline
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25
Q

Hypotheses to explain changes in hare

birth and survival rates: 2

A 
2. Predation by lynx and other predators
can explain drop in survival rates, but…
• hare birth rates drop during the decline
phase.
• Hare numbers rebound slowly after
predator numbers plummet.
• The physical condition of hares worsens
as hares decrease in number
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26
Q

exploitation

A

a relationship in
which one organism benefits by feeding
on, and directly harming, another:
+ / - relationship

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27
Q

Herbivore

A

eats tissues of living plants

or algae.

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28
Q

Predator

A

kills and eats other

organisms, referred to as prey

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29
Q

Parasite

A 
lives in or on another organism
(its host), feeding on parts of it. Usually
doesn’t kill the host.
-Some parasites (pathogens) cause
disease.
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30
Q

Parasitoids

A

are insects that lay an
egg on or in another insect host.
After hatching, larvae remain in the
host, which they eat and usually kill.

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31
Q

sit-and-wait predators

A

remaining in one place and attacking
prey that move within striking distance
ie) sessile animals, such as
barnacles, and carnivorous plants

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32
Q

Crypsis

A

The prey is camouflaged, or resembles its background.

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33
Q

Mimicry

A

The prey resembles another organism that is toxic or very fierce.

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34
Q

Behavior

A

• Not foraging in open
areas.
• Keeping lookouts.
• Defensive circles.

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35
Q

Masting

A

some produce huge numbers of seeds in

some years and hardly any in other years

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36
Q

Compensation

A

Removal of plant tissue stimulates

new growth.

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37
Q

Full compensation

A

no net loss of plant tissue.

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38
Q

Structural defenses

A

tough leaves, spines
and thorns, saw-like edges, pernicious
(nearly invisible) hairs that can pierce the
skin.

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39
Q

Induced defenses

A

produced in response
to herbivore attack. Some cacti increase
spine production after being grazed.

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40
Q

Secondary compounds

A 
toxic chemicals to reduce herbivory.
-Other compounds attract predators or
parasitoids that will attack the herbivores.
-Some are produced all the time; others
are induced.
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41
Q

Herbivores can use behavior to circumvent plant defenses:

A
  • Plants in the genus Bursera store toxic resins in canals in the leaves.
  • Beetles in the genus Blepharida have evolved a counter-defense
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42
Q

The Lotka–Volterra predator–prey model

A

dN/dt = rN-aNP

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43
Q

N

A

number of prey

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44
Q

P

A

number of predators

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45
Q

r

A

population growth rate

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46
Q

a

A

Capture efficiency

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47
Q

When P = 0,

A

the prey population grows exponentially.

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48
Q

With predators present (P ≠ 0),

A 
the rate of prey capture depends on:
• how frequently they encounter each
other (NP)
• efficiency of prey capture (a).
The overall rate of prey removal is aNP.
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49
Q

The Lotka–Volterra predator–prey model with mortality

A

dP/dt= baNP mP

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50
Q

m

A

mortality

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51
Q

If N = 0,

A

predator population decreases

exponentially at death rate m.

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52
Q

When prey are present (N ≠ 0),

A

individuals are added to the predator population according to:
• the number of prey killed (aNP)
• efficiency (b).

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53
Q

Zero population growth isoclines

A

can predict changes in predator and prey

populations over time.

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54
Q

Prey population

A

decreases if P > r/a; it

increases if P < r/a.

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55
Q

Predator population

A

decreases if N < m/ba;

it increases if N > m/ba.

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56
Q

experiments with a rotifer predator and algal prey species, Hairston et al. found that populations cycled, but not
synchronously. 4 possible mechanisms

A 
1. Rotifer egg viability increases with prey
density.
2. Algal nutritional quality increases with
nitrogen concentrations.
3. Accumulation of toxins alters algal
physiology.
4. The algae might evolve in response to
predation.
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57
Q

Symbionts

A

organisms
that live in or on other
organisms

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58
Q

parasite

A

consumes the tissues or body fluids of the organism on which it lives (the host).

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59
Q

Pathogens

A

are parasites

that cause diseases.

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60
Q

Herbivores

A

aphids or nematodes that feed on one or a few host plants

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61
Q

Parasitoids

A

insects whose larvae feed on a single

host and almost always kill it.

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62
Q

Macroparasites

A

large species such as arthropods and worms

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63
Q

Microparasites

A

microscopic, such

as bacteria

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64
Q

haustoria

A

Dodder gets water and food from the host plant via specialized
roots

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65
Q

hemiparasitic

A

they get water and nutrients from the host but can also photosynthesize.
ie) mistletoes

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66
Q

ectoparasites

A

many fungi are this

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67
Q

endoparasites.

A

Many disease organisms

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68
Q

Mycobacterium tuberculosis,

A

the bacterium that causes

tuberculosis

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69
Q

ectoparasitism advantage

A
  • change host

- don’t have to counteract immune defenses

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70
Q

ectoparasitism disadvantage

A

-exposed to predators

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71
Q

endoparasitism advantage

A
  • protected

- stable enviroment

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72
Q

endoparasitism disadvantage

A

-find host

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73
Q

Parasites exert strong selection pressure

A

on their

host organisms, and vice-versa.

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74
Q

parasite impact on communities

A

Parasites can reduce the sizes of host populations
and alter the outcomes of species interactions,
thereby causing communities to change.

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75
Q

Ecosystem engineer

A

species can change the physical character

of the environment, as when a beaver builds a dam

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76
Q

dynamics and spread of disease formula

A

dI/dt = βSI - mI

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77
Q

β

A

transmission coefficient (how effectively the disease spreads)

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78
Q

m

A

mortality and recovery rate

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79
Q

A disease will spread when

A

dI/dt > 0

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80
Q

ST = m/β

A

A disease will establish and spread when
the number of susceptible individuals
exceeds threshold density,

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81
Q

Climate change impact on spreading of disease

A 
Range shifts may put more or fewer
people at risk
• Control efforts
• Ecological interactions involving
pathogens and hosts
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82
Q

From Chemicals to Evolution and

Ecosystems

A

Interactions between enslaver parasites and
their hosts provide evidence of previous
evolutionary change:
• Enslaver parasites have many adaptations
to cope with host defenses.
• A parasite that uses a chemical is well
adapted to take advantage of the body
chemistry of its host.

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83
Q

Positive interactions

A

-occur when neither species is
harmed and the benefits of the interaction are
greater than the costs for at least one species.
-are those in which one or both species benefit
and neither is harmed. (= Facilitation)

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84
Q

Mutualism

A

Mutually beneficial interaction between individuals of two

species (+/+).

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85
Q

Commensalism

A

Individuals of one species benefit, while individuals

of the other species do not benefit and are not harmed (+/0).

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86
Q

Symbiosis

A

A relationship in which the two species live in close

physiological contact with each other, such as corals and algae.

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87
Q

Symbioses

A

can include parasitism (+/–), commensalism (+/0), and

mutualism (+/+).

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88
Q

Most plants form mycorrhizae

A

-Symbiotic associations between the roots
and various fungi.
-The fungi increase the surface area for the plant to take up water and soil
nutrients

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89
Q

Ectomycorrhizae

A

The fungus grows between root cells and
forms a mantle around the
root.

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90
Q

Arbuscular mycorrhizae

A

The fungus grows into the soil, extending away from the root; and also penetrates into some of the plant root
cells.

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91
Q

Ecological interactions can evolve into

commensalism or mutualism

A

• Lichens on tree leaves -> initially harm the tree by blocking
sunlight.
• The Australian palm has adapted by increasing the
concentration of chlorophyll in leaves with lichens.

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92
Q

Obligate mutualisms

A 
Tropical figs are pollinated by fig wasps.
• Neither species can
reproduce without the
other.
• The wasps and the figs
have coevolved.
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93
Q

Facultative Mutualism

A 
Some ants protect treehoppers from predators
• the treehoppers secrete
“honeydew” (sugar solution),
which the ants feed on.
• Treehoppers always secrete
honeydew, so ants always
have this resource.
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94
Q

Each partner in a mutualistic interaction

A

acts
in ways that serve its own ecological and
evolutionary interests.

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95
Q

Trophic mutualisms:

A

Mutualist receives energy or nutrients from its partner.

96
Q

Habitat mutualisms

A

One partner provides the other with shelter, living space, or favorable habitat

97
Q

Service mutualisms:

A

One partner performs an ecological service for the other.

98
Q

Cheaters

A

are individuals that increase offspring production by overexploiting their mutualistic partner

99
Q

“Penalties”

A

may be imposed on cheaters

100
Q

Communities

A

communities are groups of interacting species that

occur together at the same place and time

101
Q

A physically defined community

A

might encompass all the species in a sand dune, a mountain stream, or a desert.

102
Q

biologically defined community

A

might include all the species associated with a kelp forest, a freshwater bog, or a coral reef.

103
Q

Taxonomic affinity

A

e.g., all bird species in a community

104
Q

Guild

A

group of species that use the same resources. (typically in the same way)

105
Q

Functional group

A

species that function in similar ways, but do not necessarily use the same resources.

106
Q

Interaction webs

A

describe both trophic (vertical) and non-trophic (horizontal)
interactions

107
Q

Community structure

A

is the set of characteristics that shape communities

108
Q

Species richness

A

the number of species in a community.

109
Q

Species evenness

A

relative abundances compared with one another.

110
Q

Species diversity

A

combines species richness and species evenness.

111
Q

Shannon diversity index

A 
pi = proportion of individuals in the ith species
s = number of species in the community
112
Q

Biodiversity

A

describes diversity at multiple spatial scales, from genes to species to communities.

113
Q

Species diversity

A

(and biodiversity) often used broadly to mean the number of species in a community.

114
Q

Rank abundance curves

A

plot the proportional abundance of each species (pi) relative to the others in rank order.

115
Q

Species accumulation curves

A

species richness is plotted as a function of the total number of individuals that have been counted.

116
Q

Species composition

A

identity of species in a community.

117
Q

Communities can be characterized by

A

complex networks of direct and indirect interactions that vary in strength and direction.

118
Q

Direct interactions

A

occur between two species (e.g., competition, predation, and facilitation).

119
Q

Indirect interactions

A

occur when the relationship between two species is mediated by a third (or more) species

120
Q

Trophic cascade

A

Effect across more than onetrophic level

121
Q

Trophic facilitation

A

A consumer is indirectly facilitated by a positive interaction between its prey and another species.

122
Q

Competitive networks

A

Competitive interactions among multiple species in which every species negatively interacts with every other species.

123
Q

Indirect effects

A

can arise from horizontal interactions at one trophic level.

124
Q

Interaction strength

A

Magnitude of the effect of one species on the abundance of another species
-Measured by removing one species (the interactor species) from the community and observing the effect on the other species (the target species)

125
Q

Dominant species, or foundation species

A

have large effects due to high abundance or biomass.

126
Q

Keystone species

A

have a strong effects because of their roles in the community. Large effect in proportion to their
abundance

127
Q

Ecosystem engineers

A

species that create, modify, or maintain physical habitat for themselves and other species

128
Q

Succession

A

is change in species composition in communities over time.

129
Q

Disturbance

A

Events that injure or kill some individuals and create opportunities for other individuals.

130
Q

Stress

A

An abiotic factor reduces the growth or reproduction of individuals.

131
Q

Primary succession

A

involves the colonization of habitats devoid of life (e.g., volcanic rock).

132
Q

Secondary succession

A

involves reestablishment of a community in which some, but not all, organisms have been destroyed (fires, storms, logging, etc.).

133
Q

Climax stage

A

a stable end point that changes little

134
Q

Space fro substitution

A

Could predict how communities would change over time without actually waiting for the pattern to unfold.

135
Q

Early stages showed aspects of facilitation

A

plants modified the habitat in positive ways for other plants and animals.

136
Q

As succession progresses, larger,

A

slow-growing and long-lived species begin to

dominate.

137
Q

Biogeography

A

is the study of patterns of species composition and diversity across geographic locations

138
Q

species richness and composition vary:

A
  • by latitude

- continent to continent

139
Q

Alpha diversity

A

species diversity at the community level

140
Q

Beta diversity

A

Change in species number and composition, or turnover of species, from one community type to another.
-connects local and regional scales

141
Q

Gamma diversity

A

Regional species pool —all the species contained within a region.

142
Q

Alfred Russel Wallace

A

father of biogeography

-co-discoverer of natural selection

143
Q

The six biogeographic regions correspond roughly to Earth’s

A

six major tectonic plates.

144
Q

Vicariance

A

evolutionary separation of species by barriers such as those formed by continental drift.
ex) The large flightless birds (ratites) had a common ancestor from Gondwana.

145
Q

Global patterns of species richness should be controlled by three processes:

A

Speciation, extinction, and dispersal.

146
Q
  1. Species diversification rate:
A

• The tropics have the most land area on Earth
• Speciation by geographic isolation would be more
likely.
-Temperatures are very stable.

147
Q
  1. Species diversification time
A

The tropics more climatically stable over time,
species have had more time to evolve.
• Temperate and polar regions have undergone
severe climatic changes such as glaciation,
disrupting species diversification.

148
Q
  1. Productivity or Carrying Capacity
A

-Productivity is highest in the tropics (terrestrial).
-High productivity promotes large population sizes
because carrying capacity is larger.

149
Q

An important concept in biogeography is the species–area relationship

A

species richness increases with area sampled.

150
Q

species-area relationship

A

Species–area curves plot species richness (S) of a sample against area (A) of the sample.
-The relationship between S and A is estimated by linear regression:

151
Q

equilibrium theory of island biogeography.

A

The number of species on an island depends on a balance between immigration or dispersal rates and
extinction rates.

152
Q

Habitat fragmentation

A

also creates large edge effects at the transition between forest and matrix habitat.

153
Q

Biofuels

A

liquid or gas fuels from plant material (biomass).

154
Q

“filters”

A

exclude species from communities.

155
Q

Biotic resistance

A

occurs when interactions with the native species exclude the invader.

156
Q

Resource partitioning

A

Competing species coexist by using resources in different ways

157
Q

Resource ratio hypothesis

A

Species coexist by using resources in different proportions.

158
Q

Species diversity should be the greatest when?

A

at intermediate levels of disturbance

159
Q

Low levels of disturbance

A

competition reduces diversity

160
Q

Intermediate levels of disturbance

A

species involved in positive interactions are released from competition and can increase diversity

161
Q

High levels of disturbance

A

positive interactions are common and help to increase diversity.

162
Q

Lottery models

A

emphasize the role of chance in maintaining species diversity.

163
Q

Lottery Model

A

Most relevant in very diverse communities
where many species overlap in their
resource requirements.
• Its relevance decreases in communities in
which species have large disparities in
interaction strength.

164
Q

Species diversity can control community functions,

A

such as plant productivity, soil fertility, water quality,

etc.

165
Q

Community stability

A

the tendency of a community to remain the same in structure and function.

166
Q

Four hypotheses

A

have been proposed to explain the positive relationship between species diversity and community function.

167
Q

Two variables in all the hypotheses

A

• Degree of overlap in ecological function of species.
• Variation in strength of the ecological functions of
species.

168
Q

Complementarity hypothesis

A

-As species richness increases, there will be a
linear increase in community function.
•Each species added has an equal effect.

169
Q

Redundancy hypothesis

A

-The functional contribution of additional
species reaches a threshold.
•As more species are added, there is overlap in
their function, or redundancy among species.

170
Q

Driver and passenger hypothesis

A

• Strength of ecological function varies greatly:
• “driver” species have a large effect
• “passenger” species have a minimal effect.
• Addition of driver and passenger species will have
unequal effects on community function.

171
Q

A variation on the driver and passenger

hypothesis

A

It assumes there could be overlap between driver and passenger functions.

172
Q

biofuels and agriculture

A

-These lands could produce enough fuel to
substitute for 13% of global oil consumption and
19% of electricity; and reduce CO2 emission by
15%.
• Biofuels vary in the biomass and energy required to
make them.
-This is 4–5 months of driving for the average individual in the United States.
– The same amount of corn could feed one person
for 20–27 years.

173
Q

Ecosystem

A

all the components of an ecological system, biotic and abiotic, that influence the flow of energy and elements.

174
Q

Primary production

A

is the chemical energy generated by autotrophs during photosynthesis and chemosynthesis (source of energy for all organisms, from bacteria to humans)

175
Q

Primary productivity

A

is the rate of primary production.

176
Q

Gross primary production (GPP)

A

total amount of carbon fixed by autotrophs.

• GPP depends on photosynthetic rate.

177
Q 
Photosynthetic rate is influenced by climate and leaf
area index (LAI)
A

leaf area per unit of ground area.

178
Q

Net primary production (NPP):

A 
NPP = GPP – Respiration
• NPP represents biomass gained by the
plant.
• NPP is the energy left over for plant
growth, and for consumption by
detritivores and herbivores.
• NPP represents input of carbon in
ecosystems.
179
Q

It is important to be able to measure NPP

A
  • NPP is the ultimate source of energy for all organisms in an ecosystem.
  • Variation in NPP is an indication of ecosystem health.
  • NPP is associated with the global carbon cycle.
180
Q

Harvest techniques

A

Measure biomass before and after growing season

181
Q

Measuring belowground NPP is more difficult

A

-Fine roots turn over more quickly than
shoots—they die and are replaced quickly.
• Roots may exude carbon into the soil, or
transfer it to mycorrhizal or bacterial
symbionts.
• Harvests must be more frequent, and
additional correction factors are needed

182
Q

Chlorophyll absorbs

A
  • blue and red wavelengths and has a characteristic spectral signature
  • Plants also reflect near-infrared wavelengths
183
Q

NDVI (normalized difference vegetation index):

A

-NIR = Near-infrared wavelengths (700-100 nm)

• red = red wavelengths (600 – 700 nm)

184
Q

NDVI and remote sensing

A

can be used to estimate CO2 uptake and NPP, deforestation, desertification, atmospheric pollution, and other phenomena.

185
Q

The net change in CO2 is GPP minus total respiration

A

Net ecosystem production or exchange (NEE).

186
Q

What does most of the photosynthesis in aquatic habitats?

A

Phytoplankton
-Phytoplankton have short life spans, so biomass at
any given time is low compared with NPP; harvest
techniques are not used

187
Q

What is NPP constrained by?

A

both physical and biotic factors

188
Q

What controls NPP in terrestrial ecosystems?

A

nutrients, particularly nitrogen

189
Q

NPP in lakes

A
  • limited by phosphorus and nitrogen

- NPP is measured as change in chlorophyll concentrations or number of phytoplankton cells

190
Q

limnocorrals

A
  • used in lake experiments

- clear containers with open tops to which nutrients can be added.

191
Q

NPP in rivers

A

-NPP is often low
-Most of the energy is derived from terrestrial organic
matter
-Suspended sediment in rivers can limit light penetration, thus water clarity often controls NPP
-Nitrogen from agricultural and industrial practices
can result in blooms of algae and “dead zones.”

192
Q

Estuaries

A

usually nutrient-rich; variation in NPP is correlated with nitrogen inputs from rivers

193
Q

NPP in Oceans

A
  • open ocean, NPP is mainly from phytoplankton
  • Picoplankton (cells < 1 μm) contribute as much as 50% of the total marine NPP
  • coastal areas, kelp forests may have leaf area indices and rates of NPP as high as those of tropical forests.
  • “Meadows” of seagrasses such as eelgrass (Zostera) are also important in nearshore zones.
194
Q

open-ocean NPP is limited by what?

A

nitrogen

195
Q

NPP in the equatorial Pacific Ocean

A

limited by iron

196
Q

Iron and global warming

A

-Martin suggested that fertilizing the oceans with iron could reduce global warming because CO2 uptake by phytoplankton would increase
-unlikely to be the solution
-iron is lost quickly from the photic zone, sinking to deeper layers where it is unavailable to support phytoplankton
growth

197
Q

Secondary production

A

Heterotrophs get their energy by consuming organic

compounds that were produced by other organisms

198
Q

Detritivores

A

eat dead organic matter (detritus)

199
Q

Net secondary production

A

Ingestion – Respiration – Egestion

200
Q

egested

A

lost in urine and feces

201
Q

Net secondary production

A

in most ecosystems is a small fraction of NPP. The fraction is greater in aquatic ecosystems than terrestrial.

202
Q

Inuit women had PCB concentrations in their breast milk

A

seven times higher than in women in Quebec

203
Q

allochthonous inputs

A

external energy inputs in aquatic systems

204
Q

Detritus

A

dead organic matter

205
Q

autochthonous energy

A

Energy produced by autotrophs within the system

206
Q

Second law of thermodynamics

A

in transfer of energy, some is dispersed and becomes unusable:
-Energy will decrease with each trophic level.

207
Q

Trophic pyramid

A

relative amounts of energy or biomass of each trophic level

208
Q

Why don’t terrestrial herbivores consume more

of the available biomass?

A
  1. Herbivores limited by predators, never reach carrying
    capacity. Green World Hypothesis
  2. Autotrophs have defenses against herbivory, such as
    secondary compounds, spines, etc.
  3. Phytoplankton are more nutritious for herbivores than
    terrestrial plants.
209
Q

Trophic efficiency

A

Amount of energy at one trophic level divided by

the amount of energy at the trophic level immediately below it

210
Q

Assimilation efficiencies

A
  • herbivores and detritivores ~ 20%–50%

- carnivores ~ 80%.

211
Q

Animals have carbon:nutrient ratios similar to

A

the animals consuming them

212
Q

Endotherms digest food more completely than ectotherms

A

and thus have higher assimilation efficiencies

213
Q

Trophic cascade

A

A series of trophic interactions that result in changes in biomass and species composition on levels not immediately adjacent

214
Q

Hypotheses on the number of trophic levels

A
  1. The amount of energy entering via primary production: More production should allow more trophic levels.
  2. Frequency of disturbances: Higher trophic levels depend on lower levels, and take time to re-establish after disturbance
  3. Ecosystem size: Larger ecosystems support larger
    populations, have more habitat heterogeneity, and higher species diversity
215
Q

Food webs

A

are static descriptions of energy flow and trophic interactions

216
Q

Bioaccumulation

A

Some chemicals are not metabolized or excreted, and

become progressively more concentrated in tissues over an organism’ s lifetime

217
Q

Biomagnification

A

Concentration of these compounds increases in animals at higher trophic levels

218
Q

Landscape ecology

A

examines spatial patterns and their relationship to ecological processes and changes

219
Q

Landscape

A

An area in which at least one element is spatially heterogeneous; often includes multiple ecosystems.

220
Q

Heterogeneity

A

different types of landscape elements, and arrangement: mosaic

221
Q

Landscape composition

A

The kinds of elements or patches and how much of each kind is present.

222
Q

Landscape structure

A

Physical configuration of the landscape elements

223
Q

Scale

A

the spatial or temporal dimension of an object or process, characterized by grain and extent

224
Q

Grain

A

size of the smallest homogeneous unit of study (e.g., a pixel in a digital image); it determines resolution.

225
Q

Extent

A

boundary of the area or time period encompassed by the study.

226
Q

Disturbance can create landscape

A

heterogeneity

227
Q

Edges

A

(total length of habitat boundary) increase as fragmentation increases.

228
Q

Edge effects

A

biotic and abiotic changes associated with the boundary

229
Q

Abiotic edge effects

A

included higher temperatures and diurnal extremes, higher wind speeds, and more light penetration.

230
Q

Habitat fragmentation tends to increase rates of

A

of inbreeding and genetic drift and alters selection regimes for species confined to fragments

231
Q

Core areas

A

surrounded by buffer zones to mitigate human impacts

232
Q

Biological reserves

A

are smaller reserves with conservation of a single species or ecological community as the main objective

233
Q

Connectivity

A

can reduce the effects of fragmentation by preventing isolation of populations

234
Q

Corridors may also facilitate movement of

A

pathogens and invasive species

235
Q

Ecosystem management

A

attempts to maintain ecosystem sustainability, set explicit goals and policies, and use science to evaluate and adjust management practices over time

236
Q

adaptive management

A

Policies can then be adjusted as needed— an iterative process

237
Q

Three main parts of ecosystem management

A

ecological, socioeconomic, and institutional

Principles Of Ecology (2 decks)

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