Exam 3 Flashcards
(200 cards)
1
Q
structural antipredator adaptations
A
- antipredator adaptations can be plastic
- allows animal to flexibly respond to presence of predators
2
Q
mechanical defenses
A
reduce predator’s ability to capture, attack, or handle prey (ex: quills, change body shape…etc)
3
Q
plastic
A
induced only when prey detects predator in environment
4
Q
antipredator adaptations are often expensive
behavioral defenses, physical/chemical defenses, defense costs in genera
A
- behavioral defenses: costly because they result in reduced feeding activity or crowding in locations away from predators
- Physical/chemical defenses: often energetically expensive to produce
- defense costs can reduce growth, development, and reproduction
- when cost of defenses are so high that they come at the cost of growth and reproduction, the presence of predators can cause smaller prey population sizes even when they don’t consume prey
5
Q
coevolution
A
when two or more species affect each others evolution
6
Q
Lotka- Volterra model
A
a model of predator-prey interactions that incorporates oscillations in predator and prey populations and shows predator numbers lagging behind those of their prey
7
Q
equilibrium (zero growth) isocline
A
the population size of one species that causes the population of another species to be stable
- as the number of predators or prey change and moves away from equilibrium isoclines, populations will increase or decrease
8
Q
joint population trajectory
A
the simultaneous trajectory of predator and prey populations
9
Q
joint equilibrium point
A
the point at which the equilibrium isoclines for predator and prey populations cross
- if either of the populations stray from the equilibrium point, they will oscillate around the point
10
Q
functional response
A
the relationship between the density of prey and an individual predator’s rate of food consumption
11
Q
Type I functional response
A
- when a predator’s rate of prey consumption increases in a linear fashion with an increase in prey density until satiation occurs
- increase in prey density results in ever increasing number of prey consumed by predator until satiated
12
Q
Type II functional response
A
when a predator’s rate of prey consumption begins to slow as prey density increases and then plateaus; often happens because predators must spend more time handling more prey
13
Q
Type III functional response
A
- when a predator exhibits low, rapid, and slowing prey consumption under low, moderate, and high prey densities, respectively
- as pery population density increases, there is initial inc in proportion of prey consumed, as predators spend more time handling prey/get satiated, the proportion declines
- low consumtion at low prey densities may occur because predators may have less practice at locating and catching prey but develop a search image at higher densities (prey can hide, when predator has not learned search image due to low prey density, its ability to locate/capture prey is poor)
14
Q
ecological systems
A
biological entities that have their own internal processes and interact with their external surroundings
15
Q
community
A
all populations of various species living together in a particular area that interact or could potentially interact
- boundaries are not always rigid, and may cover small or large areas
16
Q
community approach
A
understands the diversity and interactions or organisms living together in the same place
17
Q
predation/parasitoidism
A
+/-
18
Q
parasitism
A
+/-
19
Q
herbivory
A
+/-
20
Q
competition
A
-/-
21
Q
mutualism
A
+/+
22
Q
commensalism
A
+/0
23
Q
struggling to define “community”
how are communities often defined
A
- communities are often categorized by their dominant organisms or by physical conditions that affect the distribution of species
24
Q
ecotone
A
- ecological transition zone
- a boundary created by sharp changes in environmental conditions over a relatively short distance, accompanied by a major change in the composition of species
25
line transect survey or ecotones
can document existence of an ecotone by using a line transect survey to determine the abundances of different species along environmental gradient-> when ecotone is present, we expect to observe sharp changes in distribution of species between communities
26
ecological release
ability of individuals to exploit broader niches
27
how we define communities
- an assemblage of species found together in a specific place at a specific time
- they interact OR have the potential to interact
- scale varies widely
- species within a community may or may not be interdependent
28
Frederic Clements
proposed that most communities are interdependent and act as superorganisms
29
Henry Gleason
proposed that most communities consist of species with independent distributions
30
interdependent community
species depend on each other to exist
31
independent community
species do not depend on each other to exist
32
If species distributions are independent:
1) they should depend only on individual habitat requirements
2) there should be gradual changes in species along a line transect
33
line transect test of interdependence
- if species are interdependent, we should observe species appearing/disappearing together
- independent= gradual changes in species composition
- similar habitat requirements happen to put various species in same place at same time
34
problem with observational studies
- cohorts of species may ALSO be evidence for similar biotic/abiotic requirements
- species may be linked by correlations with a 3rd (or 4th or 5th) variable, and not have any interdependencies with one another at all
- an abrupt transition may reflect an abrupt change in abiotic conditions whereby many species can't exist under changed conditions
35
experimental manipulation can provide evidence that can support...
causation
36
if species are interdependent
- removing a species should cause other species to decline
- if changes are neutral or positive species are independent
37
species living under harsh environmental conditions frequently exhibit...
interdependence
- helped by neighboring species to reduce harsh wind, provide shade, or offer protection from herbivores
38
species richness
the number of species in a community
39
relative abundance
the proportion of individuals in a community represented by each species
40
species evenness
a comparison of the relative abundance of each species in a community
- greatest evenness= all species have equal abundance
- least evenness= one species is abundant and others are rare
41
rank abundance curves
a curve that plots the relative abundance of each species in a community in rank order from the most abundant species to least abundant species
- to plot a rank abundance curve, rank each species in terns of its abundance; the most abundant species receives a rank of 1, the next 2... etc.
42
species diversity
communities with higher species richness and greater evenness have higher species diversity
- communities with high diversity of habitats (offer more potential niches) will also have a higher diversity of species
43
highest richness and evenness in a rank abundance curve
- highest richness= line goes out farthest
- highest evenness= line looks flattest
44
species diversity depends on
- resources available
- habitat diversity
- influential species
- disturbances
45
hump shaped curve
- initial increase in productivity associated with increase in species richness but further increase in productivity are associated with decrease in species richness
- a site with medium productivity has higher species richness than sites with low/high productivity (most productuve (resource rich) communities are dominated by a small number of superior competitors--> community with medium productivity is often the most species rich)
46
meta-analysis
statistical technique in which data from many studies ae combined to test a particular question
47
resources and species richness
- added resources caused a decline in species richness of producers (because a few species dominate, weaker competitors decline)
48
community succession
long term changes in ecological communities often follow predictable patterns
49
space and time
- communities can stretch widely geographically, or can be found on much smaller spatial scales
- "long term" change in communities is liekwise dependent ont he relative time scale--> whats long term for one community might be short-term for another
50
succession
the change in species composition over time
51
pioneer species
earliest species to arrive at a site
- typically have ability to disperse long distance and arrive quickly at a disturbance site
52
sere
each stage of community change in succession
53
Early succession/pioneer species (number of seeds, seed size, mode of dispersal, seed viability, rootshott ratio, growth rate, size at maturity, and shade tolerance)
- number of seeds: many
- seed size: small
- mode of dispersal: wind or stuck to animals
- seed viability: long
- rootshoot ratio: low (more shoot, less root)
- growth rate: fast
- size at maturity: small
- shade tolerance: low
54
late succession/climax species (number of seeds, seed size, mode of dispersal, seed viability, rootshott ratio, growth rate, size at maturity, and shade tolerance)
- number of seeds: few
- seed size: large
- mode of dispersal: gravity or eaten by animals
- seed viability: short
- rootshoot ratio: high (more root, less shoot)
- growth rate: slow
- size at maturity: large
- shade tolerance: high
55
climax community
- the last stage--> may continue to change!
- generally composed of organisms that dominate in a given biome
- shade tolerance as seedlings and large size as mature plants give competitive edge
- species composition of a climax community can still exhibit variation over space and time within a given biome
- can be short lived if a disturbance should wipe it out
- changes in community become less dramatic once the climax community develops
56
changes in plant community-->
substantial changes in the habitats that are available to animals--> cause changes in animal community
57
primary succession
- the development of communities in habitats that are initially devoid of plants and organic soil, such as sand dunces, lava flows, and bare rock
- initially inhabited by lichens and mosses that don't need soil to live
58
secondary succession
the development of communities in habitats that have been disturbed and include no plants but still contain organic soil
- occurs in plowed fields/forests uprooted by hurricanes
59
distinguish between primary and secondary succession by:
the starting point of the community
- progression of serel stages can start at different points and still end with same climax community
60
whale falls
200 years of food provided all at once in a small space
- no climax/final sere because eventually no nutrients left
61
forensic entomologists
estimate the time of death for human carcasses based on the insects found on a body and the environmental temperature
62
chronosequence
a sequence of communities that exist over time at a given location
63
carbon dating
identifies the age of the pollen in each layer--> gives us a snapshot of community structure at each "slice" of time
64
succession is often punctuated with...
- rapid periods of change
- ponds and lakes can experience long periods of several hundred years in which little succession occurs, followed by brief episodes of rapid changes
65
ability to disperse and ability to persist under existing abiotic and biotic conditions determines...
which species will appear in different serel stages during succession
66
early succession species can...
- modify the environment in ways that affect whether late succession species can become established
67
inhibition
decreasing the probability that a second species will become established
- competition, predation, parasitism
- early in succession, inhibition can prevent movement toward climax, late in succession can prevent pioneer species from colonizing and surviving
68
facilitation
a mechanism of succession in which the presence of one species increses the probability that a second species can become established
- early succession species do this by altering the environmental conditions of the site in a manner that makes it more suitable for other species to establish and less suitable for themselves (provide more organic matter in soil, shade from intense sunlight and increased soil moisture)
69
priority effect
when the arrival of one species at a site affects the subsequent colonization of other species
- when inhibition occurs in a seral stage, the outcome of an interaction depends on which species becomes established first
- facilitation, inhibition, and tolerance are priority effects
70
tolerance
a mechanism of succession in which the probability that a species can become established depends on its dispersal ability and its ability to persist under the physical conditions of the environment
- ex: species that tolerate stressful environmental conditions can become established quickly and dominate early succession
71
Connell-Slatyer model of succession
1) all succession begins with early pioneer species that produce numerous seeds, germinate early, and grow quickly
2) succession then proceeds by:
a. facilitationL early successional species modify the environment for later species to replace them
b. inhibition: early colonists dominate until a dusturbance or mortality removes them and the longer-lived late succcessional species replace them
c. tolerance: later successional species grow more slowly and eventually eplace early successional species
- a given community can include all 3 mecahnisms of succession
72
over space, climax forest communities...
vary based on environmental conditions, like soil moisture
73
over time, climax forest communities...
will experience a gradual shift in the composition of the dominant species as shading becomes increasingly prevalent
74
transient climax community
- climax community is not persistent
- occurs when site is frequently disturbed so climax community can't perpetuate itself
75
arrested development
- some communities never make it to a true climax state because of frequent disturbance
- fire maintained climax community: fire happens so frequently that plants that would usually take over that community can't be established-> fills with fire resistant plants
- grazer maintained climax community: preferentially eat most palatable plants and do not eat less palatable/better defended plants
76
can we repair some of the damage humans have done to ecosystems and biodiversity?
ecological restoration seeks to do just that, and restoration ecology is the science that underpins it
77
passive restoration
simply allowing natural succession to occur in an ecosystem after removing a source of disturbance
- ex: recovery of deciduous forests in eastern US after the abandonment of agriculture
78
active restoration
- involves accelerating the process or attempting to change the trajectory of succession
- ex: mine tailings would take so long to recover passively that active restoration is often used
79
fire maintained climax community
successional stage persists as final serel stage due to periodic fires
80
grazer maintained climax community
successional stage persists as final seral stage due to intense grazing
81
keystone species
a species that substantially affects the structure of communities, although species might not be particularly numerous
- removing a keystone species can cause a community to collapse
- keystone species can be predators, parasites, herbivores, or competitors
82
ecosystem engineers
keystone species that affect communities by influencing the structure of a habitat
83
intermediate disturbance hypothesis
the hypothesis that more species are present in a community that experiences occasional disturbances than in a community with wither frequenct or rare disturbances
84
food chain
a linear representation of how different species in a community feed on each other
85
food web
- a complex and realistic representation of how species feed on each other in a community
- arrows in a food web indicate consumption and the movement of energy and nutrients
86
trophic levels
levels in a food chain or food web of an ecosystem
- all organisms in a trophic level obtain their energy in a similar way
87
omnivores
can feed at several trophic levels
88
producers
autotrophs and plants that convert light energy and CO2 into carbs through photosynthesis (first trophic level)
89
tertiary consumers
eat secondary consumers
90
primary consumer
eat producers
91
secondary consumer
eat primary consumers
92
guild
group species based on specifically what/how they eat
- group of species that feed on similar items (leaf eaters, root chewers, nectar sippers... etc.)
93
top-down control
when the abundance of trophic groups is determined by the existence of predators at the top of the food web
94
bottom-up control
- when the abundance of trophic groups is determined by the energy available from producers
95
direct effect
an interaction between two species that does not involve other species
- the direct effect of one species often sets off chain of events that affect other species in the community
- ex: parasitism, competition, predation, mutualism
96
indirect effect
an interaction between two species that involves one or more intermediate species
- exploitative competition is an indirect effect because the two competitors are interacting with each other by feeding on common resource
- sometimes indirect effects can occur between adjacent communities
97
trophic cascade
indirect effects in a community that are initiated by a predator
ex: cod-> herring-> zooplankton-> phytoplankton-> water quality
98
density-mediated indirect effect
indirect effect caused by change in the ensity of the intermediate species
99
trait mediated indirect effects
indirect effect caused by change in the trait of the intermediate species
- commonly happens when a predator causes its prey to change its feeding behavior, which in turn alters the amount of food consumed by the prey
100
community stability
the ability of a community to maintain a particular structure
101
resistance
- how much a community changes when disturbed
- ex: removal/addition of species
102
resilience
- the time it takes after a disturbance to return to its original state
- high resilience= bouncing back quickly
103
more diverse communities are more stable
- communities with greater species richness and evenness are generally more stable
- communities with high plant diversity provide more consistently available food/habitat for all trophic levels
104
alternative stable states
- when a community is disturbed so much that the species composition and relative abundance of populations in the community change, and the new community structure is resistant to further change
- ex: removal of keystone species or dramatic change in environment
- in some cases, given enough time/ changes in environment the alternative stable state can eventually revert back to the original state
105
climate
typical atmospheric conditions that occur throughout the year, measured over many years
106
weather
variation on temp/precipitation over periods of hours/days
107
atmosphere
- thick layer of air that surrounds planet-> reflects 1/3 of solar radiation emitted toward Earth which then goes back into space
108
2/3 of sun's light
passes through atmosphere; clouds and Earth's surface re-radiate this IR radiation
109
greenhouse effect
- the process of solar radiation striking Earth, being converted to infrared radiation, and being absorbed and re-emitted back to Earth by atmospheric gases
- only the gases that absorb and re-emit infrared radiation can contribute to greenhouse effect are greenhouse gases
- N2 and O2 aren't greenhouse gases
- without greenhouse gases, Earth's temp would be about 0 degrees F
110
most prevalent greenhouse gases
water vapor and CO2
111
small changes in greenhouse gases can cause big changes in temperature
inc concentration of greenhouse gases in atmosphere-> inc avg temp of Earth (b/c greenhouse gases absorb and re-emit infrared radiation to Earth)
112
mass spectrometry
for chemical composition (bubbles)
113
stable isotope analysis of fractionation
- water
- 160 vs 180
114
concentration of CO2 in atmosphere...
substantially increased due to increased combustion of fossil fuels, electric generating plants, and industrial processes
115
what is the cause of differences in temperature around the globe
- result of how much solar radiation strikes Earth at a given location
- sunlight has farther to travel through the atmosphere towards the poles
- a given quantity of sunlight is dispersed over a greater area toward the poles
116
axis is tilted
23.5 degrees
117
march and september
sun positioned at equator
118
june
sun over 23.5 degrees north
119
September
sun over 23.5 degrees south
120
albedo
- the fraction of solar energy reflected by an object
- some surfaces have higher albedo than others; light-colored surfaces reflect more light than dark-colored surfaces
- low albedo of forests at the tropics at the equator increases average temperature
- high albedo of snow at the poles decreases average temperatures
- more solar energy reflected= higher albedo
121
atmospheric convection currents
- circulations of air between Earth's surface and the atmosphere
- formation of atmospheric currents is driven by unequal heating of Earth and because warm air holds more moisture
122
what happens as air is heated?
- as air warms, its constituent molecules fly further apart from one another, and air becomes less dense-> rises
- the surface of Earth is warm
- air next to earth warms and rises
- when it cools, it sinks back down
123
air contains water vapor so what happens to water vapor when air cools and heats?
- warmer air can hold more water vapor
- cooling air "gets rid of" water vapor it can't retain
- as water vapor condenses, it releases heat (latent heat release)
124
Hadley cells
the two circulation cells of air between the equator and 30 degrees N and 30 degrees S latitude
125
Intertropical convergence zone (ITCZ)
the area where the two Hadley cells converge and cause large amounts of precipitation
126
solar equator
- latitude that receives the most direct rays of Sun
- latitude of solar equator moves throughout the year and determines latitude of ITCZ, so latitude of ITCZ moves throughout year too-> influences seasonal rainfall
127
polar cells
atmospheric currents that move air between 60 degrees and 90 degrees latitude
128
Ferrel cells
between Hadley and polar cells, 30-60 degrees latitude, atmospheric currents lack distinct patterns
129
coriolis effect
the deflection of an object's path due to rotation of Earth
- planet spins more quickly at the equator than at the poles
- surface winds deflected to right in northern hemisphere and left in southern hemisphere
130
Hadley cells north of equator more air along surface from
north to south--> coriolis effect deflects so its NE-> SW (NE trade winds)
131
SE trade winds
below equator winds go SE-> NW
132
westerlies
winds move away from equator, toward poles-> weather in middle latitudes moves west-> east
133
ocean currents
- influence location of different climates
- general pattern: warm tropical water circulated up through western reaches of ocean basins toward tropics while the cold polar water circulates down the eastern edges of ocean basins toward tropics
134
tropical waters flow away from tropics
- water expands when heated
- water at tropics is 8 cm higher in elevation due to this expansion
- gravity pulls it downwards, water flows away from the equator
135
gyre
a large-scale water circulation pattern between continents
- gyres redistribute heat energy and influence global climates
- gyres move clockwise in N hemisphere and counterclockwise in S
- also redistribute contaminants
136
upwelling
any upward movement of ocean water
- upwelling zones have high biological productivity; deep water tends to be rich in nutrients
- upwelling occurs in locations along continents where surface currents move away from coastline
- as surface water moves away from land, cold water below moves up (rich in nutrients)
137
thermohaline circulation
a global pattern of surface and deep water currents that flow as a result of variations in temp and salinity
138
warming climate can disrupt thermohaline circulation
- influx of warm, fresh water
- thermohaline "conveyor belt" no longer works
- contributes to sea surface warming, exacerbating the problem that initiated it
- Northern Europe (and similar) temperatures drop
139
if there's global warming, why so cold
- climate does not equal weather
- climate change, not global warming
- extreme cold locally, but abnormally warm elsewhere
- warmer arctic temp = colder North American winters
140
climate change in lethal
- more summer droughts
- more wildfires
- longer intensity and aseasonal severe weather events
- more
141
how does climate affect life?
- climate differs in different regions of the world due to unequal heating by the sun, convection currents, the Coriolis effect, gyres, shape of sontinents, thermohaline circulation... etc.
- these forces together result in seasonal temperature and precipitations conditions
- regions with similar temperature and precipitation conditions tend to contain similar types of organisms--> each type of region = biome
142
in terrestrial ecosystem, biomes are categorized by...
the dominant plant forms associated with distinct patterns of seasonal temp/ precipitation
143
biome
geographic regions that contain communities composed of organisms with similar adaptations
144
aquatic ecosytsem characterized by
patterns of depth, flow, and salinity
145
convergent evolution
from unrelated ancestors (i.e. lineages that have been seperate for a long time) species develop similar traits because they cope with similar selective forces
146
climate diagrams
visualize patterns of temp and precipitation that are associated with particular biomes--> plot average monthly temp and precipitation
147
9 major terrestrial biomes
- tropical rainforest
- tropical seasonal forest/savanna
- subtropical desert
- woodland/shrubland
- temperate rainforest
- temperate seasonal forest
- temperate grassland/cold desert
- Boreal forest
148
average annual temp below 5 degrees C
boreal forest and tundra biomes
149
5- 20 degrees C
temperate biomes(temperate rainforest, temperate seasonal forest, woodland/shrubland, and temperate grassland/cold desert)
150
tropical rainforest biome
- Central America, Amazon basin, the Congo, throughout Indonesia/southeast Asia
- tall trees (up to ~60 m in height) form canopy, other shade tolerant plants in understory
- higher diversity here than in any other biome
- seasonal flooding is common
- Human uses: lumber and land cleared for agriculture
- frequently within ITCZ
- 2 peaks of rainfall on equinoxes
- organic matter decompose quickly-> rapid nutrient cycling
151
temperate rainforest biome
- Pacific northwest, southern Chile, New Zealand, southeastern Australia
- very tall trees (up to 100 m)- redwoods and Douglad fir
- most occur near oceans- maintains mild climate, long growing seasons, evergreen vegetation
- support very few species but, like tropical rainforests, have high productivity
- soils are slightly richer than those of tropical rainforest
- mild tmep, abundant precipitation
152
tropical seasonal forest/savanna biome
- Sub-Saharan Africa, southern Asia, tropical South America outside of Amazon basin
- typically adjecent to tropical rainforest near equator
- warm temps and as ITCZ moves, pronounces wet and dry seasons
- overall greater precipitation=forest; overall lower precipitation=grassland- even more rapidly disappearing than tropical rainforests- cattle heaven
153
temperate seasonal forest
- Eastern North America, Europe, east Asia
- both deciduous and evergreen forests
- temperatures dip below freezing in winters
- soil is somewhat podsolized, but not as severely as in rainforests (contains abundant organic matter)
- environmental conditions fluctuate more than temperate rainforest because not near warm ocean waters
154
woodland/shrubland biome
- "Mediterranean climate"
- Wine country.... California, southern South America, Mediterranean, Cape Province (South Africa), part of Australia
- plants limited by cold in winter, lack of water in summer (favors growth of drought-tolerant grasses and shrubs)
- sclerophyllous vegetation has small, durable leaves
- fire resistant plants
155
subtropical desert biome
- Mojave, Sahara, Arabian
- little organic matter in soills, xerophytic plants
- CAM photosynthesis common
- many endemic animals tend to be nocturnal, or have extreme physiological adaptations
- salinization often occurs
- associated with dry, descending air of Hadley cells
156
temperate grassland/cold desert biome
- AKA prairies , pampas, steppes
- frequent fires prevent trees from becoming dominant component of this biome
- cold desert created by rain shadow-> dry soils, infrequent fires, low productivity of plant community
- tend to be found in interior of continents- little rain
- soils are rich in organic matter and nutrients
- grass height correlates with rainfall
- larger vertebrate in great abundance
157
boreal forest biome
- AKA taiga
- "endless" strands of evergreen trees with needles
- needle leaf litter is one of largest reservoirs of organic carbon on Earth
- needles allow trees to resist dry, cold winds and retain moisture
- low diversity
158
tundra biome
- Arctic, edges of Antarctica
- Alpine tundra= above the tree line on the Alps, Rockies, Himalayas, etc.
- permafrost may prevent drainage, soils remain moist despite low precipitation
- dwarfed plants
- less severe conditions in alpine tundra (warmer, loger growing season, higher precipitation, less severe winters, greater productivity, higher species diversity)
- no tree growth in tundra
159
aquatic biomes
- streams/rivers
- lakes/ponds
- freshwater wetlands
- salt marshes
- amngroves
- intertidal zone
- coral reefs
- open ocean
160
streams and rivers
- streams and rivers are lotic systems (characterized by flowing fresh water)
161
autochthonous inputs
produced from inside the system (algae, plants)
162
allochthonous inputs
inputs of organic matter (e.g. leaves) come from outside the system
163
streams/creeks
narrow channels of fast-flowing fresh water
164
rivers
wide channels of slow-flowing fresh water
165
Riparian zone
band of terrestrial vegetation influenced by seasonal flooding and elevated water tables
166
lakes and ponds
characterized by non-flowing fresh water, with some areas that are too deep for emergent vegretation
167
littoral zone
shallow area around the edge of algae/pond containing rooted vegetation
168
limnetic zone
dominant photosynthetic organisms are floating algae
169
profundal zone
does not receive sunlight because of its depth (low O2)
170
benthic zone
sediments at bottom of lake/pond that provides habitat for burrowing animals and microorganisms
171
freshwater wetlands
aquatic biomes that contain standing fresh water, or soils saturated with fresh water for at least part of the year
- have emergent vegetation throughout all depths
172
swamps
freshwater wetlands that contain trees
173
marshes
freshwater wetlands that contain emergent, non-woody vegetation
174
bogs
- freshwater wetlands that contain various vegetation, but characterized by acidic conditions
- bogs are formed with a lake fills with plant debris, or when sphagnum moss covers dry land
- forms PEAT... fossil fuels of the future, and sometimes the present
175
why are bogs so importnat?
- only cover 3% of the Earth's surface, but they store 500 metric gigatons of carbon
- this is equivalent of 67% of all the CO2 in the air... or all the CO2 held in the world's boreal forests (10% of Earth's surface)
- a depth of one meter of peat corresponds to approximately 1,000 years of carbon storage
176
salt marshes/estuaries
- saltwater, non-woody vegetation
- alt marshes are found along the coasts of continents in temperate climates, often within estuaries
- estuaries= areas along coast where mouths of freshwater rivers mix with salt water from oceans, abundant nutrients, very productive
177
intertidal zone
- saltwater, the narrow band of coastline between the levels of high tide and low tide
178
mangroves
- saltwater, woody vegetation
- prevent erosion of coastal shorelines from constant incoming waves and protect against tsunami/storm surges
179
coral reefs
- warm (20C+) and shallow saltwater
- often surrounded by volcanic islands where they are fed by nutrients eroding from rich volcanic soil and by upwelling currents
- provide shelter to a wide variety-> very diverse
180
open ocean
- saltwater, everything else
- the part of the ocean that is away from the shoreline and coral reefs
181
neritic zone
extends to depth of 200m, corresponds to edge of continental shelf
- high productivity (strong waves move nutrients from below)
182
oceanic zone
beyond neritic zone, sparse nutrients, production is limited
183
benthic zone
seafloor underlying neritic and oceanic zones
184
photic zone
area of neritic and oceanic zones that contain sufficient light for photosynthesis by algae
185
aphotic zone
area of neritic and oceanic zones where water is so deep that sunlight cannot penetrate
186
landscape ecology
the field of study that considers the spatial arrangement of habitats at different scales and examines how they influence individuals, populations, communities, and ecosystems
187
landscape ecology considers how natural systems are affected by...
1) patchiness
2) habitat total area
3) connectivity of habitat patches
188
patchiness
- includes both fragmentation (natural and because of humans) and heterogeneity (which results in patches of similar and dissimilar habitats)
189
gamma diversity
the diversity (usually calculated as an index) of the regional species pool
190
regional species pool
all of the species in a region (includes many different communities)
191
alpha diversity
refers to the species diversity index within a relatively small area and more homogenous habitat (aka local diversity)
192
beta diversity
- refers to a comparison of diversity between habitats, usually measured as hte species change between habitats
- high beta diversity= two habitats are very different ( a lot of unique species between them)
193
small population
more likely to go extinct that large population
- larger population = larger area
- smaller community = smaller population = more likely to go extict
194
habitat corridors
areas that connect wildlife populations separated by human activities or structures
195
stepping stones
small intervening habitat patches that dispersing organisms can use to move between large favorable habitats
196
not well connected =
more likely to go extinct and not be recolonized
197
island biogeography
habitat patchiness, size, and connectivity- along with theory from population ecology- can help us explain the patterns of diversity that we see across communities on a large scale
- diversity should be related to the size and isolation of habitats within a patchy landscape
- area inc= more species
198
equilibrium theory of island biogeography
the number of species on an island reflects a balance between the colonization of new species and the extinction of existing species
- as equilibrium point, colonizing and going extinct at same rate
199
why are there so many species in the tropics?
- One explanation: greater speciation, lower extinction
- second explanation: Earth's history (Europe has not yet reached its new equilibrium state (island biogeography) following the last glacial maximum- tree ranges have not yet recovered)
200
energy- diversity hypothesis
- habitats with higher amount of energy (proxy, potential evapotranspiration, PET) can support more species
- can support larger populations = less extinction
- accelerate rate of evolutionary change= more speciation
