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Biology 1B Final > Ecology > Flashcards

Ecology Flashcards

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1
Q

Ernst Haeckel

A

coined the term “ecology”, the scientific study of the interactions between organisms and the environment

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2
Q

ecological system

A

ecological systems have biotic and abiotic components that interact

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3
Q

homeostasis: physiology/morphology/behavior

A

organisms maintain a set of conditions

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4
Q

population

A

group of individuals (2nd lowest group of ecological hierarchy)

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5
Q

community

A

interaction of populations of individuals of different species (just the biotic part)

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6
Q

ecosystem

A

interaction of the abiotic and biotic parts of a community

landscape = sets of ecosystems together

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7
Q

biosphere

A

highest group of ecological hierarchy, contains all ecosystems

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8
Q

climate (macro/micro)

A

largely dictated by where the sun hits the Earth
climate = average long-term conditions vs weather = short-term conditions
macroclimate: patterns on the global, regional, and landcsape level
microclimate: very fine, localized patterns, such as those encountered by the community of organisms that live in the microhabitat beneath a fallen log

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9
Q

climate diagram

A

compares temperature and precipitation, constant red line implies little variation in climate

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10
Q

monsoon

A

typically in hot areas close to oceans, temp is high all year along and heavy rain occurs in a particular season

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11
Q

seasonality

A

climate changes throughout the year, predictable weather patterns
result of which hemisphere is getting greater sun exposure

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12
Q

weather

A

weather = short-term conditions vs climate = average long-term conditions

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13
Q

angle of incidence (of the sun)

A

direct overhead exposure more likely to occur at the Equator

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14
Q

prevailing winds

A

winds do not just move north and south because the Earth spins (faster at the equator than everywhere else)
prevailing winds drive oceanic currents

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15
Q

gyre

A

large patterns of ocean movements (circular motion driven by prevailing winds)

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16
Q

currents

A

California - along CA coast, cold water coming down from Alaska, pushes water off coast and causes upwelling
Gulf Stream - from Caribbean north along East Coast and to Europe, keeps E Coast warmer than it would be otherwise
Antarctic circumpolar - goes all the way around the Antarctic, emphasizes how much more water there is in S hemisphere than N hemisphere

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17
Q

topography

A

“lay of the land” - in CA, precipitation occurs on windward side of mountains, prevailing winds come from the West and create cold air

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18
Q

windward/leeward

A

windward side is closer to the ocean/coast, leeward side is over hills/mountains

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19
Q

rain shadow

A

occurs on leeward side of mountains

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20
Q

dispersal

A

organism dispersal can be predicted based on directions of prevailing winds, storms, and jet streams
definition is movement of individuals or gametes away from their area of origin or from centers of high population density
contributes greatly to the global distribution of organisms

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21
Q

Mediterranean climate

A

we have one here in the Bay Area, the actual Mediterranean, and S Hemisphere
Northern and Southern Med climates have different patterns

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22
Q

biome (von Humboldt)

A

von Humboldt - biogeographer who traveled extensively, saw characteristic sets of plants in different locations, which changed on mountains according to elevation

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23
Q

canopy

A

upper layer of forest

forest is based on vertical layer of vegetation`

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24
Q

disturbance

A

event such as a storm, fire, or human activity that changes a community, removing organisms from it and altering resource ability
disturbance rather than stability tends to be the rule

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25
Q

tropical forest

A

rainfall is relatively constant, about 200-400 cm annually in tropical rainforests
tropical dry forest - precipitation is highly season
temperature is high year round with little seasonal variation
tropical forest vegetation is usually vertically layered with intense competition for light
highest biodiversity of any terrestrial biome

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26
Q

desert

A

occur in bands near 30 degrees north and south latitude or at other latitudes in the interior of continents
temperature is variable seasonally and daily, can be very high or very low
dominated by low widely scattered vegetation, many plants do CAM photosynthesis

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27
Q

savanna

A

occurs in equatorial and subequatorial regions
dry season can last up to eight or nine months
warm year-round, but with more seasonal variation than tropical forests
scattered trees are thorny with small leaves; fires are common in the dry season
grasses and forbs make up most of the ground cover, most animals are large and plant-eating or predators

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28
Q

chaparral

A

occurs in midlatitude coastal regions on several continents and is widely distributed
fall, winter, and spring are cool and summer is warm
dominated by

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29
Q

temperate grassland

A

eg plains and prairies of central North America
precipitation is often highly seasonal with relatively dry winters and wet summers; periodic drought is common
winters are generally cold while summers are hot
dominant plants are grasses and forbs, many grasses have adaptations to help survive drought
native mammals include large grazers like bison and wild horses

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30
Q

northern coniferous forest (taiga)

A

largest terrestrial biome on Earth, extending in a broad band across N America and Eurasia to the edge of the arctic tundra
precipitation varies
winters are usually cold and summer may be hot
dominated by cone-bearing trees, such as pine, spruce; conical shape of conifers prevents too much snow from accumulating and breaking their branches
lots of migratory birds

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31
Q

temperate broadleaf forest

A

found mainly at midlatitudes in the Northern Hemisphere
precipitation highest in fall, sometimes winter snow
cold winters, hot and humid summers
mature TBF has distinct vertical layers, including a closed canopy
dominant plants are deciduous trees, which drop their leaves before winter when low temps would reduce photosynthesis
many mammals hibernate in winter

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32
Q

tundra

A

covers expansive areas of the Arctic and alpine tundra on very high mountaintops
low precipitation
winters are very cold, summers also cold
vegetation is mostly herbaceous - mosses, grasses, forbs; permanently frozen layer of soil called permafrost restricts the growth of plant roots
large grazing species and predators

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33
Q

oceans

A

make up the largest marine biome, covering about 75% of Earth’s surface
water evaporated from the oceans provides most of the planet’s rainfall
ocean temperatures have a major effect on global climate and wind patterns
(aquatic biomes are classified by marine or freshwater)

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34
Q

coral reefs

A

formed largely from the calcium carbonate skeletons of corals
shallow reef-building corals live in the photic zone of relatively stable tropical marine environments with high water clarity
require high oxygen levels and a solid substrate for attachment
corals are main organisms, but overall biodiversity is very high

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35
Q

intertidal zones

A

periodically submerged and exposed by the tides, wice daily on most marine shores
upper zones experience longer exposure to air and greater variations in temperature and salinity
oxygen and nutrient levels are generally high and renewed with each turn of the tides
high diversity and biomass of attached marine algae
many heterotrophs

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36
Q

estuaries

A

transition area between river and sea; seawater flows up the estuary channel during a rising tide and flows back down during the falling tide
salinity varies within estuaries, from fresh water to seawater
nutrients from the river make estuaries very productive biomes
complex networks of tidal channels, islands, etc
saltmarsh grasses and algae

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37
Q

rivers

A

most prominent physical characteristic is speed and volume of flow
river - water generally warmer and more turbid than streams
salt and nutrient content increases from oxygen-rich headwaters to the mouth
headwater streams may be rich in phytoplankton or rooted aquatic plants, also a great diversity of fishes and invertebrates

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38
Q

lakes

A

standing body of water covering large areas
oligotrophic - nutrient poor and generally oxygen rich
eutrophic - nutrient rich and often depleted of oxygen in the deepest zone, covered with ice in winter
littoral zone - shallow, well-lit waters close to shore
limnetic zone - far from shore, too deep to support rooted aquatic plants, but has phytoplankton and drifting heterotrophs

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39
Q

wetlands

A

habitat inundated by water at least some of the time and that supports plants adapted to water-saturated soil
both water and soils are periodically low in dissolved oxygen
basin wetlands - develop in shallow basins
riverine wetlands - developing along river and stream banks
water-saturated soils favor the growth of plants

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40
Q

zonation

A

many aquatic biomes are physically and chemically stratified
photic, aphotic make up pelagic
benthic
abyssal

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41
Q

photic/aphotic

A

photic zone - upper part of pelagic zone, where there is sufficient light for photosynthesis
aphotic zone - lower zone where little light penetrates

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42
Q

pelagic/benthic

A

pelagic zone - made up of photic and aphotic zone, above benthic and abyssal zone
benthic zone - bottom of all auatic zones, deep or shallow; made up of sand and organic and inorganic sediments, occupied by communities of organisms collectively called the benthos
major source of food for benthic species is detritus

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43
Q

abyssal

A

part of the ocean 2000-6000 m below the surface

deep in the aphotic zone

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44
Q

continental shelf

A

“surface” of land in aquatic biomes

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45
Q

hydrothermal vents

A

dark, hot environments where food producers are chemoautotrophic prokaryotes
located on mid-ocean ridges, deep sea
marine benthic zone

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46
Q

thermocline (thermal stratification)

A

narrow layer of abrupt temperature change that separates the uniformly warm upper layer of a lake/ocean from the more uniformly cold deeper waters
lakes tend to be especially layered except for turnover in temperate lakes

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47
Q

turnover

A

temperate lakes undergo a semiannual mixing of their waters as a result of changing temperature profiles
sends oxygenated water from a lake’s surface to the bottom and brings nutrient-rich water from the bottom to the surface in both spring and autumn

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48
Q

continental drift

A

plate tectonics have enabled us to figure out the history of the continents
continental drift has changed the makeup and nature of organisms on continents, which had to move or adapt or go extinct

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49
Q

biotic zones (Wallace)

A

Wallace recognized that different places on Earth had different sets of organisms, he called these biogeographic regions
only recently did we associate that with plate tectonics

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50
Q

biotic exchange

A

occurs when continents come together
eg we got marsupials in N America from S America when the continents came together, and S America got bears etc from here

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51
Q

vicariance (compare with dispersal)

A

occurs when the range of a species or lineage is split apart

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52
Q

immigration/emigration

A

immigration - influx of new individuals from other areas

emigration - movement of individuals out of a population and into other locations

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53
Q

geographic range

A

how widespread a species is

eg Devil’s hole pupfish has a very small range, while humpback whale has a very large range

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54
Q

generation time

A

amount of time taken for a cohort to go from birth to when all the individuals are dead

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55
Q

sex ratio

A

ratio of male to female

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56
Q

exponential growth (multiplicative)

A

describes population growth in an idealized, unlimited environment
you know what exponential growth is why’d you even make this dumbass flashcard

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57
Q

territoriality

A

defense of a bounded physical space against encroachment by other individuals
often results in uniform patterns of dispersion

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58
Q

habitat patches

A

clumped dispersion
habitats are patchy even on a small scale
organisms are not distributed randomly in space
help prevent extinction because even if one patch undergoes a disturbance, the species is distributed in other patches as well

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59
Q

habitat occupancy

A

set of patches vary over time in whether they’re occupied or not

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60
Q

BD model

A 
B = births
D = deaths
Nt+1 = Nt + B - D 
∆N/∆t = B - D
ignores immigration and emigration (for now)
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61
Q

population growth equations

A 
b = per capita birth rate (fecundity)
m = per capita death rate (mortality) 
r = per capita rate of increase
r = b - m 
r = 0, zero population growth (ZPG)
∆N/∆t = rN 
rinst  = instantaneous, intrinsic or innate
dN/dt = rinstN, a maximum rate of increase
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62
Q

fecundity, fertility

A

fertility - TFR total fertility rate is the expected number of children born per woman in her child-bearing years
fecundity - average number of young per female of age x

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63
Q

reproductive table

A

fertility schedule - age-specific summary of the reproductive rates in a population
constructed by measuring the reproductive output of a cohort from birth until death
tallies the number of female offspring produced by each age-group for sexual species

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64
Q

cohort

A

randomly selected group of individuals of the same age

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65
Q

survivorship curve (3 types)

A

Type I - flat at the start, reflecting low death rates during early and middle life, and then drops steeply as death rates increase among older age groups (examples are many large mammals including humans) - inverted L, opposite of type III
Type II - intermediate, with constant death rate over the organism’s life span (occurs in squirrels, rodents, plants, etc.) looks like a downward slope like my GPA
Type III - looks like an L which is what I’ll be taking on this midterm, drops sharply at the start reflecting very high death rates for those few individuals that survive the early period of die-off

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66
Q

life cycle

A

the stages that an organism goes through in its life, not to be confused with life table etc

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67
Q

carrying capacity (K)

A

maximum number of organisms supported by a particular environment and its resources

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68
Q

logistic growth (sigmoid, S-shape)

A

per capita rate of increase approaches zero as the population size nears the carrying capacity

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69
Q

iteroparity

A

repeated reproduction
eg female loggerhead turtles produce four times in a year
organisms tend to produce relatively few but large offspring each time they reproduce, and they provide for the offspring better
favored in more dependable environments, where adults are more likely to survive to breed again and where competition for resources may be intense

70
Q

r-selected

A

density-independent selection
selection for traits that maximize reproductive success in uncrowded environments (low densities)
said to maximize r, the per capita rate of increase and occurs in environments in which population densities are well such conditions are often found in disturbed habitats

71
Q

principle of allocation: life history trade-offs, cost of reproduction, etc.

A

principle of allocation - only have so much food, resources, energy etc that can be allocated into survivorship or reproduction etc (not conscious decisions, but if energy is available it is possible to invest more into a wider range of activities)
trade offs: reproduction or survival

72
Q

life history

A

how resources are divided
entails 3 main variables:
when reproduction begins (the age at first reproduction or at first maturity)
how often the organism reproduces
how many offspring are produced per reproductive episode

73
Q

K-selected

A

density-dependent selection
selection for traits that are sensitive to population density and are favored at high densities
said to operate in populations living at a density near the limit imposed by their resources (the carrying capacity) when competition among individuals is stronger

74
Q

density-dependent

A

birth rate or death rate does not change with population density
examples - mortality of grass due to physical factors that kill same proportion of a local population regardless of density, ilke drought stress

75
Q

density independent

A

death rate that increases with population density or a birth rate that falls with rising density
eg scarcity of water or nutrients with more organisms
key factors regarding birth rate are density dependent, while death rate is largely regulated by density-dependent factors

76
Q

equilibrium, equilibrium density

A

combination of density-dependent and density-independent factors can stop population growth, resulting in equilibrium population density

77
Q

Allee effect

A

individuals may have a more difficult time surviving or reproducing if the population size is too small
for example, a single plant may be damaged by excessive wind if it is standing alone, but it would be protected by a clump of individuals

78
Q

minimum viable population

A

minimal population size at which a species is able to sustain its numbers

79
Q

effective population size

A

total population size may be misleading because only certain members of the population breed successfully and pass on traits
effective population size is based on the breeding potential of the population, incorporates sex ratio

80
Q

BIDE model

A

incorporates immigration and emigration as well as births and deaths

81
Q

rescue effect

A

if a subpopulation in a metapopulation disappears, it can be rescued by organisms moving to that path or by researchers moving organisms to a patch to rescue it

82
Q

habitat corridor

A

mechanism to increase connectivity between populations so that the organisms can move from one habitat to another
management strategy, example of conservation biology

83
Q

interspecific interactions

A

include competition, predation, herbivory, symbiosis, and facilitation
interactions with other individuals of the other species in the community

84
Q

interspecific competition

A

a -/- interaction that occurs when individuals of different species compete for a resource that limits their growth and survival

85
Q

consumer-resource interactions

A

predation - +/- in which one species kills and eats the other
herbivory - +/- interaction in which an organism eats parts of a plant or alga
parasitism - +/- in which one organism derives its nourishment from another organism, which is harmed in the process
pathogen interactions - +/- probably

86
Q

mutualism

A

(+/+) - interspecific interaction that benefits both species
eg nitrogen fixation by bacteria in the root nodules of legumes, nutrient exchange between fungi and plant roots
obligate mutualism - one species cannot survive on its own
facultative mutualism - both species can survive on their own

87
Q

commensalism

A

(+/0) - interaction between species that benefits one of the species but neither harms nor helps the other

88
Q

facilitation

A

species can have positive effects on the survival and reproduction of other species without necessarily living in the direct and intimate contact of a symbiosis
particularly common in plant ecology

89
Q

symbiosis

A

when individuals of 2 or more species live in direct and intimate contact with one another - all such interactions, whether they are harmful or not

90
Q

ecological niche

A

sum of a species’ use of the biotic and abiotic resources in its environment

91
Q

fundamental niche

A

niche potentially occupied by a species identified by testing the range of conditions in which a species grows and reproduces in the absence of competitors

92
Q

realized niche

A

portion of the fundamental niche that an organism actually occupies

93
Q

competitive exclusion (Gause)

A

two species competing for the same limiting resources cannot coexist permanently in the same place; in the absence of disturbance, one species will use the resources more efficiently and reproduce more rapidly than the other
even a slight reproductive advantage will eventually lead to local elimination of the inferior competitor
Gause - noted this phenomenon in paramecium experiment

94
Q

resource partitioning

A

differentiation of niches that enables similar species to coexist in a community
eg using different resources or using the same resources at different times of day or the year

95
Q

pathogens

A

disease-causing microorganisms, viruses, viroids, or prions

produce especially clear effects when introduced into a new habitat, important in clear effects

96
Q

zoonotic pathogens

A

pathogens that are transferred to humans from other animals, either through direct contact with an infected animal or by means of an intermediate species

97
Q

rarity advantage

A

species tend to do better when they are rare (while they remain rare)
will not have to face as much competition from other species or from other members of their own species

98
Q

interspecific equations (Lotka-Volterra)

A 
extension of logistic equations
predator and prey
dN1/dt = r1N1(K1-N1-aN2)/K1
dN2/dt = r2N2 (K2-N2+BN1)/K2
species 1 is prey, species 2 is predator because 1 is hurt by greater presence of 2 while 2 benefits from greater presence of 1
99
Q

character displacement

A

character (trait) has undergone selection due to competition and species have differentiated the nature of their traits in response
eg finches with large beaks vs small beaks in response to competition
another example of how organisms can coexist

100
Q

propagule pressure

A

invasions are the result of increased dispersions

propagule is an organism that can start somewhere else, typically a seed

101
Q

R0, basic reproduction number

A

for transmitted pathogens - number of individuals that you will infect if you are infected while you have the disease
influenced by duration of infectivity of affected patients, infectiousness of the organism, number of susceptible people in the population
used in modeling disease

102
Q

herd immunity (threshold, HIT)

A

herd immunity - if enough people are vaccinated in a population, the disease can’t really get started and move through the population
threshold for this to be possible is the HIT

103
Q

diseases

A

measles - highest R0
influenza - lower R0 than ebola
ebola - zoonotic
zika - zoonotic

104
Q

intermediate disturbance hypothesis

A

states that moderate levels of disturbance foster greater species diversity than do high or low levels of disturbance
high levels of disturbance reduce diversity by creating environmental stresses that exceed the tolerances of many species etc
low levels can reduce diversity by allowing competitively dominant species to exclude less competitive ones
intermediate: opens up habitats for occupation by less competitive species, rarely create severe conditions

105
Q

ecological succession

A

ecological succession is when species are gradually replaced by other species, which are in turn replaced by still other species
primary - process begins in a virtually lifeless area where soil has not yet formed, such as new volcanic island
secondary - when an existing community has been cleared by some disturbance that leaves the soil intact; area may return to something like its original state

106
Q

role of earlier species in succession

A

facilitation - early arriving species may facilitate appearance of later species by making the environment more favorable
inhibition - early species may inhibit later species so that successful colonization by later species occurs in spite of, not because of, early species
tolerance - early species may be completely independent of later species, which tolerate conditions created by earlier ones but are neither helped nor hindered

107
Q

stability

A

community’s tendency to reach and maintain a relatively constant composition of species

108
Q

species composition

A

the species and factors that make up a community

109
Q

community structure

A

3-dimensional structure of communities as they develop

110
Q

species turnover (in space or in time)

A

composition of species changes from place to place (in space)

111
Q

community assembly

A

how a community forms and assembles over time

112
Q

transect

A

linear sample

go along through an area, sample at a periodic distance, and see what organisms are there

113
Q

edge effect

A

at the edges of habitats (ecotones), ecological conditions are different resulting in different types of species specializing there
microclimates can be different around edges also
also important in conservation biology

114
Q

ecotone

A

area of transition between two different habitat types

115
Q

decomposition

A

elephant dung beetles and dung decomposition - many different organisms make use of dung from the moment that it is produced throughout its decomposition process

116
Q

trophic interactions/structure

A

trophic structure - feeding relationships between organisms in a community

117
Q

biomass

A

total mass of all organisms in a habitat

118
Q

food chain (length)

A

food chains are relatively short - why?
energetic hypothesis - most common, suggests that length of a food chain is limited by the inefficiency of energy transfer along the chain; food chains should be longer in habitats of higher photosynthetic production, since the amount of stored energy in primary producers is higher
body size/metabolic hypothesis - carnivores in a food chain tend to be larger at successive trophic levels, large carnivores generally cannot live on very small food items because they cannot obtain enough food to meet their metabolic needs; also carnivore size and feeding mechanism places an upper limit on size of food it can eat
abundance/dynamic stability hypothesis -

119
Q

food web

A

food chains are not isolated units but are linked together in food webs
ecologists diagram the trophic relationships of a community using arrows that link species according to who eats whom

120
Q

autotrophs

A

= primary producers
photoautotrophs - use light
chemoautotrophs - use chemical compounds
make their own food good for them

121
Q

heterotrophs

A

do not produce their own food like autotrophs (are consumers)

122
Q

primary consumers

A

(herbivores) eat primary producers

123
Q

secondary, tertiary consumers

A

(carnivores) eat primary consumers, tertiary eats secondary, etc etc

124
Q

omnivores

A

can eat either primary producers or primary consumers

125
Q

food chain (length)

A

food chains are relatively short - why?
energetic hypothesis - most common, suggests that length of a food chain is limited by the inefficiency of energy transfer along the chain; food chains should be longer in habitats of higher photosynthetic production, since the amount of stored energy in primary producers is higher
body size/metabolic hypothesis - carnivores in a food chain tend to be larger at successive trophic levels, large carnivores generally cannot live on very small food items because they cannot obtain enough food to meet their metabolic needs; also carnivore size and feeding mechanism places an upper limit on size of food it can eat
abundance/dynamic stability hypothesis - all organisms have some randomness in numbers, so the few individuals at the top trophic levels may be more subject to chance events

126
Q

bottom up vs top down models

A

bottom-up model: postulates a unidirectional influence from lower to higher trophic levels (presence or absence of mineral nutrients N controls plant V numbers, which control herbivore H numbers, which control predator P numbers)
N–>V–>H–>P
top-down model: postulates the opposite, predation mainly controls community organization because predators limit herbivores, which limit plants, which limit nutrient levels N

127
Q

production efficiency

A

percentage of energy stored in assimilated food that is not used for respiration
Production efficiency = (net secondary production x 100%)/assimilation of primary production

128
Q

biomass pyramid

A

each tier represents the standing crop (the total dry mass of all organisms) in one trophic level
most narrow sharply from primary producers at the base to top-level carnivores at the apex because energy transfers between trophic levels are so inefficient
certain aquatic ecosystems have inverted biomass pyramids where primary consumers outweigh the producers (occur because producers are phytoplankton who grow and reproduce and are consumed so quickly by zooplankton that they never develop a large population size or standing crop = short turnover time)

129
Q

species diversity

A

species diversity is the variety of different kinds of organisms that make up the community and has two components:
species richness - number of different species in a community
relative abundance - proportion each species represents of all individuals in the community

130
Q

biodiversity hot spot

A

relatively small area with numerous endemic species and a large number of endangered and threatened species
highest conservation priority

131
Q

dominant species

A

species in a community that are the most abundant or that collectively have the highest biomass
no single explanation for why a species becomes dominant, possibly because they are competitively superior at exploiting resources or because they are most successful at evading predation and disease

132
Q

keystone species

A

not usually abundant in a community but exert strong control on community structure by their pivotal ecological roles, or niches

133
Q

ecosystem engineers

A

(foundation species)

species that dramatically alter their environment, like beavers

134
Q

habitat islands

A

can be on land, like lakes, mountain peaks separated by lowlands, or habitat fragments

135
Q

habitat fragmentation

A

any patch surrounded by an environment not suitable for the “island” species

136
Q

primary production

A

amount of light energy converted to chemical energy in the form of organic compounds by autotrophs during a given time period

137
Q

secondary production

A

amount of chemical energy in consumers’ food that is converted to their own new biomass during a given period

138
Q

albedo

A

solar radiation that strikes the planet and then is reflected back into space

139
Q

NPP

A

net primary production
NPP = GPP - Ra
Ra = amount of energy used by primary producers in their own respiration

140
Q

NEP

A

net effective production
NEP = GPP - Rt
Rt = amount of energy used by all organisms as part of respiration

141
Q

standing crop

A

total dry mass of all organisms (can be thought of as similar to population size)

142
Q

eutrophication

A

runoff adds considerable nutrients to lakes, promoting the growth of primary producers
when primary producers die, detritivores decompose them, depleting the water of much or all of its oxygen

143
Q

trophic (ecological) efficiency

A

10% loss of energy at every trophic level, meaning that 10% intake by primary consumers of primary producers will result in 1% of NPP reaching secondary consumers and so on

144
Q

net production pyramid

A

trophic levels are arranged in tiers, width of each tier is proportional to the net production of each trophic level
highest level, which represents top-level predators, represents relatively few individuals
used to represent the loss of energy with each transfer in a food chain

145
Q

carbon cycle

A

photosynthesis by plants removes atmosphere CO2, converts carbon to organic forms that are used by consumers
CO2 is added back to the atmosphere through cellular respiration by producers and consumers
burning of fossil fuels and wood is adding significant amounts of additional CO2 to the atmosphere
ocean acidification

146
Q

ecological guild

A

functional groups that overlap some in resource use, but generally perform similar functions in the community

147
Q

niche complementarity

A

species can make use of resources in different ways which complement one another, can be more productive

148
Q

latitudinal gradient of species richness

A

number of species increases the closer you get to the equator
tropics have highest species richness

149
Q

hypotheses for latitudinal gradient of species richness

A

evolutionary age/climate stability - climate in tropical regions has remained roughly the same, so there has been more time for these species to evolve and diversity for one another

longer growing season/less seasonal variation - seasonal variation is lowest at the tropics, therefore the organisms have a longer period of time in any given season to mate and evolve

more energy - more solar radiation at the equator because the sun is more directly overhead; food webs are enabled to be longer and more complex, more energy to be made use of by species

(sun)/water/evapotranspiration
spatial-area (null models) - tropics are largest in size

150
Q

alpha diversity

A

diversity at one place, richness in one area

high in the tropics (lots of species at each location)

151
Q

beta diversity

A

diversity from one place to another

low in the tropics (species are the same from place to pace)

152
Q

island equilibrium theory (Equilibrium Theory of Island Biogeography)

A

MacArthur and Wilson -
equilibrium will eventually be reached where the rate of species immigration equals the rate of species extinction
number of species at this equilibrium point is correlated with the island’s size and distance from the mainlandisland equilibrium theory (Equilibrium Theory of Island Biogeography)
not just oceanic islands, but also habitat islands
assume: distance affects colonization
island size affects extinction

153
Q

island equilibrium theory (Equilibrium Theory of Island Biogeography)

A

MacArthur and Wilson -
equilibrium will eventually be reached where the rate of species immigration equals the rate of species extinction
number of species at this equilibrium point is correlated with the island’s size and distance from the mainlandisland equilibrium theory (Equilibrium Theory of Island Biogeography)
not just oceanic islands, but also habitat islands
assume: distance affects colonization
island size affects extinction

154
Q

conduction

A

heat is transferred because two things are next to each other; the Earth is next to the atmosphere

155
Q

convection

A

atmosphere is actually moving so heat moves also

156
Q

evapotranspiration

A

total amount of water transpired by plants and evaporated from a landscape
useful predictor of NPP along with annual precipitation
also another way that the Earth is warmed

157
Q

dead zones

A

result of eutrophication - oxygen has been removed from an aquatic ecosystem

158
Q

el Nino/la Nina

A

weather patterns that tend to cycle every 5-7 years
researchers unsure why these cycles occur
typically begin with warm water in the Western Pacific which starts to accumulate, then spreads out to different parts of the world (el Nino)
la Nina is opposite pattern
implications for public health

159
Q

biogeochemical cycle

A

nutrient cycles that involve both biotic and abiotic components
energy flows but matter cycles

160
Q

organic/inorganic

A

anything related to carbon is organic, anything else is inorganic (typically minerals)

161
Q

available/unavailable

A

available or unavailable for life to make use of it, used to categorize biosphere compartments
eg available = living organisms, detritus
unavailable = peat, coal, oil are not available as nutrients

162
Q

flux

A

movement of things between compartments of biosphere

163
Q

leaching process

A

when things move out of rocks or out of the atmosphere and become available for life, like minerals leaching out of the soil

164
Q

nitrogen cycle

A

nitrogen fixation NH2 to NH4 (ammonium), form that plants can use
microbes turn NH4 into nitrates NO3
denitrification turns NO3 nitrates into N2

165
Q

phosphorus

A

nucleid acids, phosphate PO4

fertilizers, animal waste leading to eutrophicatio

166
Q

iron

A

chlorophyll synthesis, animal enzymes

limited in oceans, sinks

167
Q

ozone

A

upper atmosphere: filters UV

ground level: leads to pollution, respiratory disease

168
Q

tipping point

A

disturb an ecological system so far that it cannot respond and will not be restored on its own

169
Q

state shift

A

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds

170
Q

global forcing

A

radiative forcing - difference of sunlight absorbed by the Earth and energy radiated back into space

171
Q

urban ecology

A

examines organisms and their environment in urban settings

reflects a shift toward species preservation even in the context of cities

Biology 1B Final (3 decks)

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