Final Exam Flashcards
1
Q
Two main drivers of evolution
A
Descent and modification
2
Q
Variation
A
Indivuals that make up the population
3
Q
Inheritance
A
Some variation between indivuals has a genetic basis and is passed to offspring
4
Q
Fitness differences
A
Some indivuals contribute more offspring to the next generation
5
Q
Mutation
A
Change in the DNA sequence that leads to new allele
6
Q
What level does natural selection occur at
A
Indivual
7
Q
What level does evolution occur at
A
Population
8
Q
Direct fitness
A
Direct descendents
9
Q
Indirect fitness
A
Non-descendant relatives
10
Q
Adaptation
A
Heritable trait that promotes fitness
11
Q
Life history
A
-size at birth
-growth pattern
-age of maturity
-number and size of offspring
12
Q
Habitat
A
Set of resources in an area necessary to support a population
13
Q
Autotroph
A
Producers, bottom up effects
14
Q
Heterotrophs
A
Herbivores
Carnivores
15
Q
Habitat association
A
The regular occurrence of a species in a particular habitat
16
Q
Habitat use
A
The way animal actually uses resources in a particular area
Distribution: where animals are detected
Abundance: how many indivuals are detected
Density: number of indivuals detected per unit area surveyed
17
Q
Unsuitable habitat
A
No such thing, habitat is species specific
18
Q
Habitat preference
A
The likelihood of a resource being chosen if offered on an equal basis with others
19
Q
Habitat availability
A
The accessibility and procurability of the physical and biological components of a habitat
20
Q
How to measure habitat preference
A
Compare use vs availability
21
Q
Habitat selection
A
The hierarchical process of choosing resources in the environment
22
Q
Scale
A
spatial or temporal dimension of an object or process
23
Q
Patch
A
a relatively homogenous
area within an ecosystem
24
Q
Stand
A
a spatially contiguous group
of trees with uniformity in age-class
distribution, competition, and
structure
25
Landscape
A mosaic of patches
that differ in ecological properties
26
1st order habitat selection – geographic range
Geographic range – the spatial extent within which a species is found
27
2nd order habitat selection – home range
Home range – area used by an individual to acquire the resources needed to survive
and reproduce
28
3rd order habitat selection
choosing a patch in the home range
29
4th order habitat selection
how elements in a patch are used
30
Habitat element
a structure or group of structures used by a species (e.g., log, snag,
understory vegetation)
31
Proximate cue
an element of habitat structure and composition, or other aspect of
the biotic community that individuals use to predict resource availability
32
Decision-making is often influenced by the behavior of others
Location cue – based on physical location
Public information – based on performance
33
ecological trap
a low-quality habitat that cannot sustain a population yet is
preferred over available, high-quality habitat
34
Density dependence
a process within a population that is influenced by the
number of individuals in a defined area.
35
Ecological disturbance:
a relatively discrete
event in time that disrupts ecosystem, community,
or population structure and changes resources,
substrate availability, or the physical environment.
36
Biological legacy
living organisms, organic
matter, and biological patterns that persist from
the pre-disturbance ecosystem and influence
development patterns in the post-disturbance
ecosystem.
37
Allogenic drivers (external):
replacement of one community by
the next when processes relatively
external to community causes
change via the physical, chemical,
and biotic environment
38
Autogenic drivers (internal):
replacement of one community by
the next because of changes in
physical, chemical, and biotic
environment produced by resident
organisms
39
Forest archetype 2
(chronic
disturbances)
40
Forest archetype 1
(episodic
disturbances)
41
Mesophication:
removal of fire leads to
the development of
shade-tolerant, less fire-
adapted community, with
a moister microclimate
42
Components
of forest
structure
1. Live trees
biomass, basal area, volume, density, tree size,
spatial patterns, composition, canopy layering,
canopy structure
2. Snags
biomass, basal area, volume, density, size,
composition, state of decay, presence of cavities
3. Dead and Down Wood
biomass, size, state of decay, presence/absence
of bark
4. Understory Vegetation
cover, height, composition, functional groups,
spatial pattern
43
old growth
There is no one definition for old-growth forests, but key characteristics
include old trees, accumulations of dead wood, and structural
complexity
44
are there multiple pathways to early seral forests?
yes
45
what is an early seral forests?
forest in the initial stage of development post disturbance
46
Ecological disturbance
a discrete event in
time that disrupts ecosystem, community, or
population structure and changes resources,
substrate availability, or the physical
environment
47
Ecological disturbances are characterized by 3 components
1. Return interval: average time between disturbance events
Understory burn Volcanic eruption
Temporal scale
2. Pattern: size and configuration
Canopy gap Insect outbreak
Spatial scale
Wildfire
3. Severity: degree of physical change (e.g., amount of vegetation removed)
High severity - AustraliaMixed severity – Oregon
48
Ecological succession
the change in types, numbers, and grouping of organisms that occupy
an area over time, and concomitant changes in the microenvironment
49
Sere
he series of biotic communities formed by the process of succession
50
Silviculture
the art and science of growing stands of forest vegetation
51
Silvicultural system
planned set of treatments by which forest
vegetation is regenerated, manipulated, and often harvested
52
Uneven-aged systems
leads to a stand that contains ≥ 3 cohorts (age groups)
53
Even-aged systems – result in stands of a relatively uniform age and size,
including 2-aged systems
A single cohort stand with one canopy layer
#1. Clearcut – stand is harvested to produce a new stand of single or mixed
species; natural or artificial regeneration used
Douglas-fir,
western Oregon
#2. Seed Tree – trees left scattered in otherwise clearcut areas to provide seed for
natural regeneration; trees usually removed after regeneration is established
#3. Shelterwood – trees are left for primarily for protection from temperature
extremes; trees usually removed after regeneration is established
Northern red and pin oak uplands
Brian Lockhart, USDA Forest Service, Bugwood.org
White pine with eastern hemlock regeneration
54
Variable retention harvesting
harvesting based on the retaining structural elements
and/or biological legacies from the harvested stand to achieve ecological objectives
55
Three key benefits of variable retention for forest wildlife
1. Structural enrichment of
established stands
2. Life-boating to provide
refugia for limited-dispersal
species
3. Connectivity is enhanced
via “stepping stones”
Variable Retention Adaptive Management Experiment (VRAM) on Vancouver Island | Beese et al. 2005
56
Uneven-aged systems
leads to a stand that contains ≥ 3 cohorts (age groups)
A multiple cohort stand with multiple canopy layers
57
Single-tree selection
cutting of individual trees to form small
canopy gaps to release seedlings, saplings, and small trees
58
High-grading
cutting only
the most valuable trees on a
stand, leaving low-quality
trees behind
Sometimes called “selective
cutting” (but don’t confuse
with selection systems)
Problematic for wildlife
because many high-value
species produce seeds and
59
Group selection
cutting small groups of trees to form canopy gaps across the stand; size
ranges from several trees to ~2 acres, but the size of the patch is important!
60
#3. Habitat loss & fragmentation
primary causes of species loss
61
Extent
how large of an area an animal considers to be important
62
Grain
the minimum resolution perceived by an animal
63
Composition
What patches are present, and how abundant are they?
64
Configuration
What is the size and spatial arrangement of patches?
65
Connectivity
How are the patches in the landscape connected?
66
Landscape composition
the abundance and variety of patches, but not their spatial arrangement
67
Patch
a relatively
homogenous area
within a landscape
68
Matrix
amount of
non-habitat within
a landscape
69
Patch isolation
distance from one patch to its nearest neighbor
70
Core area
the portion of a habitat patch that is not influenced by edge effects
71
Edge effect
changes that occur at the occur at the boundary of two or more land cover types
Edge area influenced
72
Hard edge
abrupt transition between adjacent stands; stronger structural differences
73
Soft edge
gradual transition between adjacent stands; stronger floristic differences
74
Area sensitivity
when a species is less likely to occur – or is less abundant – in small patches
75
Forest loss
reduction in the total area of forest
76
Forest fragmentation
reduction in total forest area + isolation of the remaining patches
77
Four key mechanisms for species loss from fragments
1. Species-area effects: total extent of area is reduced
2. Species-environment effects: changes in abiotic conditions alter habitat quality
3. Species-interaction effects: changes in food web organization
4. Species-isolation effects: poor dispersing species cannot recolonize after local extinction
78
Landscape connectivity
the functional relationship among habitat patches due to the (1) spatial
arrangement of habitat and (2) movement responses of organisms to landscape structure
79
Structural connectivity
measured by analyzing
the landscape structure independently of an
organism
80
Functional connectivity
measured by
analyzing the behavioral response of a
particular organism to landscape elements
81
There are three patch-based measures of connectivity
* Nearest neighbor: limited info on patch network, contains no info on dispersal of focal species
* Neighborhood buffer: easy to implement, but results are sensitive to radius selected
* Incidence-function model: more biologically realistic, but requires much more information
82
Dispersal
movement of an individual from its natal location to the site of reproduction (natal
dispersal), or the movement between successive sites of reproduction (breeding dispersal)
83
Gap crossing
the distance between patches that a species is willing, or able, to traverse
84
Perceptual range
the greatest distance from which an animal can detect habitat, as determined
by its ability to orient towards a habitat edge
85
Keystone species
indirectly modify their
environment disproportionately to their biomass
86
Indicator species
indicative of overall
ecosystem function and tied to particular
environmental conditions
87
Umbrella species
species with large area
requirements
88
Listed species
species with regulatory
requirements for monitoring and/or recovering
populations
89
Coarse filter (landscapes):
Maintaining a
diversity of ecosystem types across the
landscape, with the intent of meeting the
needs of most native species
90
TRIAD approach to balance conservation and human needs
Reserve: managed for biodiversity conservation, which
typically means little or no intervention
Intensive (= plantation silviculture): planting of native or
exotic tree species, use of herbicide to control competing
vegetation, thinning, and fertilization
Extensive (= ecological forestry): typically characterized by
partial retention, mixed species, minimal use of external
inputs and reliance on natural tree regeneration
91
The fundamental niche
the full range of conditions under which a species survives
and persists in the absence of competition; typically based on physiological tolerances
92
The realized niche
the
observed environmental
biophysical conditions which a
species uses in the presence of
competition (and interactions)
with other organisms
93
Invasion ecology
involves biodiversity and
community ecology, considering which
species are successful invaders – and why –
and asking what properties of ecosystems
facilitate or inhibit invasion.
94
Exotic/non-native species
presence due to
intentional or accidental introduction as a result of
human activity
95
Casual species:
non-natives that reproduce
occasionally but do not form self-sustaining
populations; instead, they rely on repeated
introductions for persistence
96
Naturalized species
non-natives that reproduce
consistently and sustain populations over time
without direct intervention by humans
97
Invasive species
non-natives that grows quickly,
and spreads to the point of disrupting communities or ecosystems
98
Biological invasions occur because of
Traits: morphological, phenological, functional, competitive ability
Ecosystem: disturbance regime, successional stage, resource availability
Propagule pressure: availability, abundance, mobility, proximity
99
Residence time
probability
of invasion depends on
time since introduction,
and subsequent increased
propagule pressure
100
Invasion meltdown hypothesis
The invasion meltdown
hypothesis proposes that non-
native species facilitate one
another's invasion.
101
Umbrella species
species with large
area requirements (e.g., Greater Sage-
Grouse)
102
Flagship species
charismatic
species with wide popular appeal (e.g.,
Sumatran Tiger)
103
Species richness
number of species
in the community
104
Species evenness
relative abundance
of different species
105
Species diversity
integration of richness
and evenness
106
Alpha Diversity
species diversity at a
single location
What is alpha (α) diversity?
Site A: α = 4
Site B: α = 6
107
Beta Diversity
difference in species
diversity between
locations
108
Gamma Diversity
total species diversity
within a landscape
What is gamma (𝜸𝜸) diversity?
Sites A + B = 10
... but 3 species at both sites, so...
𝜸𝜸 = 7
109
Productivity hypothesis
posits that
the more energy in a system, the
more biomass it has and, in turn,
more species can be supported
110
Intermediate disturbance
hypothesis
Species diversity is highest when
disturbance is neither too rare nor
too frequent
111
Resilience
the capacity of an ecosystem to absorb disturbance so it retains essential
structures, processes, and feedbacks, and to reorganize following disturbance
112
Sustainability
the capacity to provide
ecosystem goods and services today
without compromising the ability of future
generations to meet their needs
113
Forest ecology
key principle #1
Forest ecosystem structure and function is
governed by interactions among living
organisms and their physical environment
Chapin et al. 2011
114
Forest ecology
key principle #2
The biological communities and
environmental factors that shape forest
ecosystems are dynamic in space and time.
115
Forest ecology
key principle #3
Ecological processes are interconnected
over a wide range of spatial and temporal
scales. What occurs in one location is
influenced by that location’s surroundings.
HJ Andrews Forest
116
Forest ecology
key principle #4
Forest ecosystem structure, community
composition, and species traits heavily
influence ecosystem processes and
functions.
117
Forest ecology
key principle #5
Forest ecosystem structure and function are
impacted by humans, both directly and
indirectly.
118
Forest ecology
key principle #6
There is a vast amount we don’t know about
forest ecosystems, so a precautionary
principle of forest management is needed.
And more science
119
Functional connectivity
the degree to
which the landscape facilitates or impedes
movement of ecological processes (e.g.,
organisms, materials, energy)
120
Structural connectivity
physical
connectedness among parts of the
landscape
