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Eco > Final > Flashcards

Final Flashcards

1
Q

What is a community?

A

all populations of species living together in a
particular area

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2
Q

Challenges of measuring an ecological
community:

A
  1. Difficult to count ALL species present
    -Therefore, often specify - all plant species, frugivore community
  2. Community boundaries often gradual
  3. Species can move in and out of communities
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3
Q

What do we mean by Community structure?

A

1) which species are in the community

2) what is relative abundance of each species

3) what are the relationships among the species

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4
Q

Ecotone

A

-changes in the environmental conditions
-ex: soil type, geology, water
- aspect, disturbance (grazing, plowing)

a boundary created by sharp changes in environmental conditions over a relatively short distance, accompanied by a major change in the composition of species

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5
Q

Detecting an ecotone:

A

run a transect from non-serpentine to
serpentine

  • note which species are present at each point
    along the transect
  • ecotone – where we see a shift from one set
    of species to another
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6
Q

What is serpentine soils?

A

low nutrients, high in metals

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7
Q

interdependent communities

A

communities in which species depend on each other to exist

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8
Q

independent communities

A

communities in which species do not depend on each other to exist

-species just happen to live together cuz they have similar requirments/adaptions

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9
Q

What is species richness?

A

the number of species in a community

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10
Q

Why is species richness often higher at an ecotone than not at an ecotone?

A

-generalists can live there and some of the species from each of the 2 communties xan live there

  • overlap between communties
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11
Q

Community structure:

A
  • Which species are in the community?
  • What is the relative abundance of each
    species?
  • What are the relationships among species?
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12
Q

abundance:

A

the number of individuals

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13
Q

relative abundance:

A

the proportion of all individuals represented by each species

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14
Q

What is species evenness?

A

-evenness is highest when all species have equal abundance

a comparison of the relative abundance of each
species in a community

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15
Q

Rank-abundance curves

A

plot the relative abundance of each species in a
community in order from most to least abundant

steeper = less even

never a complete even species

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16
Q

log-normal distribution

A

a normal, or bell-shaped, distribution that uses a log scale on the x-axis

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17
Q

Diversity indices:

A

a way to compare the diversity of communities that takes into account species richness AND evenness

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18
Q

Simpson’s index:

A

a measurment of species diversity, given by formula on page

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19
Q

Shannon’s index:

A

a measurment of speices diversity given by formula on page

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20
Q

intermediate disturbance hypo

A

found that hump-shaped relationships found in <20%

the hypo that more species are present in a community that occasionally experiences disturbances than in a community that experiences frequent or rare disturbances

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21
Q

(1) Productivity (resources)

A

species richness can be affected by the the amount of resoucres available (soil nutrients)

  • productivity is measured by biomass = more resources
  • relationships found in nature between productivity and species richness: hump-shaped is most common
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22
Q

Ecologists have found that-

A

as more and more resources are added, the number of plant species goes down

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23
Q

What causes more and more resources that are added, the number of plant species goes down

A

at high levels of resources, it allows a few dominant competitors to outcompete the other species

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24
Q

whether the relationship between productivity and species richness looks positive, negative, or hump-shaped can depend on -

A

the RANGE of productivity in the experiment

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25
Q

Habitat diversity

A
  • communities with a greater diversity of habitats

-habitats tend to have more species
- more niches available

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26
Q

Keystone species

A
  • the presence of a keystone species can lead to greater species richness (even if that species is not very abundant)
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27
Q

Disturbance

A

Can also affect species richness in a community
ex: hurricanes, wildfires, logging, ploughing

ecologists agree that disturbance (type, severity, frequency) affects community structure
- but the IDH is controversial

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28
Q

What local factors can affect community species richness?

A

(1) The amount of resources (productivity)
(2) Diversity of the habitat
(3) Presence of keystone species
(4) Disturbance intensity or frequency

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29
Q

food chain

A

a linear representaion of how different species in a community feed on each other

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30
Q

food web

A

a complex and realistic representaion of how psecies feed on each other in a community

-who eats whom?

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31
Q

Why do ecologists want to know who eats who?

A

-understand feeding relationships

-how one species change in abundance can affect another

-weather a species can survive in an area

-what would happen if one species goes extinct

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32
Q

Trophic levels:

A

a level in a food chain or food web of an ecosysytem

  • all species in a trophic level get their energy
    in a similar way
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33
Q

When discussing trophic levels, a guild is:

A

a group of species that feed on similar items.

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34
Q

Do species in the same guild have to be closely related?

A

no,
-ex, ants and rodents

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35
Q

primary consumer

A

a species that eats producers

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36
Q

secondary consumer

A

species that eats primary consumers

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37
Q

tertiary consumers

A

a species that eats secondary consumers

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38
Q

omnivore

A

a species that feeds at several trophic levels

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39
Q

Types of indirect effects

A

Density-mediated

Trait-mediated

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40
Q

Density-mediated

A
  • caused by changes in the DENSITY of intermediate species

-fish eat dragonfly larve = less dragonfly density= less predation on pollenators

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41
Q

Trait-mediated

A
  • caused by changes in the TRAITS of the intermediate species

-mediated
-behaviour

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42
Q

indirect effects

A

an interaction between two species that involves one or more intermediate species

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43
Q

direct effect

A

an interaction between two species that does not involve other species

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44
Q

trophic cascade

A

indirect effects in a community that are initaiated by a predator

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45
Q

density-mediated indirect effect

A

an indirect effect caused by changes in the density of an intermediate species

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46
Q

trait mediated indirect effect

A

an indirect effect caused by changed in the traits of an intermediate species

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47
Q

community stability

A

the ability of a community to maintain a particular structure

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48
Q

community resitance

A

the amount that a cmmunity changes when acted upon by some disturbance, such as the addition or removal of a species

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49
Q

community resilience

A

the time it takes after a disturbance for a community to return to its original state

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50
Q

alternative stable state

A

when a communtity is disturbed so much that the species composition and relative abdundance of populations in the community change, and the new community structure is resistant to further change

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51
Q

bottom up effect

A

happens at the bottom and affects all

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52
Q

top down effect

A

or “tropic cascade”

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53
Q

what regulates populations?

A

both top down and bottom up together

(1) the world is green (plants are doing well!), therefore, something must be controlling the herbivore populations

(2) that must be the predators

(3) therefore predators are the most important (top-down control)

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54
Q

Succession:

A

the process by which the species composition of a community changes over time

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55
Q

Seral stage:

A

each state of community change during the process of succession
e.g. early seral, late seral, climax community

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56
Q

Climax community:

A

the final stage in succession

does not mean permanent or totally stable

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57
Q

Pioneer species:

A

the first species to arrive at a site

-get succession going (partly started)

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58
Q

how can we study succession?

A

1) direct observation

2) indirect observation

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59
Q

chronosequence (indirect)

A

a series of sites that differ in age since abandonment or disturbance, but otherwise occur on similar soil types and environmental conditions

land rising up gradually
-farther from water= older communities

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60
Q

direct observation

A

-keep returning to the same site overtime and record which species are there

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61
Q

ASSUMPTIONS for Chronosequence

A

1) every site foes through the same stages

2) the sites vary in AGE only
ex- same climate, same rock underneath

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62
Q

Indirect methods

A
  • Chronosequence (space for time)
  • Paleoecological methods
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63
Q

Paleoecological methods

A

can use instead of chronosequence

Paleoecology is the study of the relationship between extinct organisms and their environments.

-pollen in lake sediments
-tree rings

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64
Q

Observe it directly over time pros and cons

A

PRO: no assumptions of space-for-time

CONS: 1) have to wait a long time (especially long species like trees)
2) maybe have only 1 example (n=1)

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65
Q

Indirect methods pros and cons

A

PRO: takes less time!

CONS: 1) have to make assumptions
2) paleoecological proxies have variable resolutions
- ex, cant differentiate to species, maybe only to genus using pollen for trees

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66
Q

Why might direct observation of succession be easier in intertidal communities than in terrestrial communities?

A

Organisms in an intertidal area have shorter generation times than organisms in terrestrial communities.

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67
Q

Types of succession in terrestrial
environments:

A

Primary succession

Secondary succession

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68
Q

Primary succession

A

“start from scratch”
- habitats start with NO plants and NO organic soils

sand dunes, lava, bare rock, volcanic ash

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69
Q

Secondary succession

A

habitat has been disturbed, no plants but DO have organic soils and could have seeds or roots

plowed fields, forest fires

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70
Q

Species traits: for early seral

A

seeds = many
seed size = small
dispersal mode = wind/ stuck to animals
seed viability = long
root:shoot ratio = low
Growth rate = fast
Size = small
Shade tolerance = low

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71
Q

Species traits: for late seral

A

seeds = few
seed size = large
dispersal mode = gravity/ eaten by animals
seed viability = short
root:shoot ratio = high (many roots)
Growth rate = slow
Size = large
Shade tolerance = high

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72
Q

What causes succession?
Why does the composition of the community shift over time?

A

-condtions are changing (light, soil)
-caused by other species

Facilitation:

Inhibition:

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73
Q

Facilitation:

A

the presence of one species INCREASES the probability that a second species can become established
-ex, alder trees, n-fixing creats greater n availabliity in soil, which allows spruce to colonize

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74
Q

Inhibition:

A

the presence of one species DECREASES the probability that a second species can become established

ex- maple and beech trees casting deep shade prevents early seral from growing there

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75
Q

What is NOT an example of inhibition?

A

A species acts as a nurse plant and increases water available to other species.

(its helping so no)

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76
Q

How can you determine whether a particular species is FACILITATING or INHIBITING another species? (or, neither?)

A

HYPOTHESIS: acorn barnacles are facilitating macroalgae

if the hypothesis is true, then areas with acorn barnacles removed will have significantly lower density of algae than the control after 2 years

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77
Q

“Climax” communities are not unchanging

A

-small disturbances can create shifts in species composition
- e.g. old tree dies, falls = GAP
- gap can be colonized by early-seral species
- community overall is in late-seral stage, but has some early-seral species due to the gap

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78
Q

what is a GAP

A

pockets of early succession

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79
Q

priority effect

A

when the arrival of one species at a site affects the subsequent colonization of other species

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80
Q

transient climax community

A

a climax community that is not persistent

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81
Q

fire-maintained climax community

A

a successional stage that persists as the final seral stage due to periduic fires

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82
Q

grazer-maintained climax community

A

when a successional stage persists as the final seral stage due to intense grazing

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83
Q

Primary productivity:

A

The rate at which solar or chemical energy is captured and converted into chemical bonds by photosynthesis or chemosynthesis

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84
Q

Standing crop:

A

the biomass of producers present in an ecosystem in a given area and at a particular moment in time

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85
Q

gross primary productivity (GPP)

A

the rate at which energy is captured and assimilated by producers in an area

86
Q

Net Primary productivity (NPP)

A

the rate of energy that is assimilated by producers and converted into producer biomass in an area

87
Q

How can we measure Net Primary Productivity (NPP)?

A

(1) measure the biomass of producers at the beginning and at the end of a growing season

(2) Measure the uptake and release of CO2 by producers

(3) Measure the uptake and release of
O2 by producers

(4) Remote Sensing

88
Q

measure the biomass of producers NPP assumptions

A

no losses to herbivory and disease

also often/usually measure only above - ground biomass

89
Q

Measure the uptake and release of CO2 by producers examples

A

1) put a plant in a jar, measure co2 uptake in the light = NPP
-repeat in dark - to estimate co2 production from respiration

GPP = NPP + respiration

2) do on a larger scale, using flux tower- measure co2 concentrations at different heights

90
Q

Measure the uptake and release of O2 by producers- why not CO2, how

A

can’t measure CO2 in aquatic systems, because:

co2 = biocarbonate ions
-put water with algae in a jar
- in light: measure o2 produced (NPP)
-in dark: measure o2 consumed - respiration

91
Q

Remote Sensing how

A

-for very large scales
- photos or imaging from a plane/satellite
-reflections of green light- if high that means high standing crop
-measure change over time to measure NPP

92
Q

eqested energy

A

the portion of consumed energy that is excreted or regurgitated

93
Q

assimilated energy

A

the portion of energy that a consumer digests and absorbs

94
Q

respired energy

A

the portion of assimilated energy a consumer uses for respiration

95
Q

net secondary productivity

A

the rate of consumer biomass accumulation in a given area

96
Q

What limits NPP?

A

1) temperature
2) precipitation
3)nutrients
4) light

97
Q

temperature limitaion

A

-as mean annual temperature increases, NPP increases.

wHy? - warmer, = longer growing season
= higher productivity

98
Q

precipitation limitation

A

NPP peaks around 3m of annual precipitation

at low precipitation levels, NPP also low

with very high precipitation, NPP is low again

nutreints leaching out of soil + low decompostion in waterlogged soils (low nutrients)

99
Q

nutrients limitations

A

-need nutrients like N + P to make important molecules (protiens)

-low nutrients = low NPP

-in oceans, NPP can also be limited by lack of silicon + iron

100
Q

light limitations

A

in water- deep underwater = not much light

101
Q

NPP around the world

A

-highest NPP in the tropics (near equator)

-shallow areas near coastlines

-shallow = more availability
-nutrients from land

102
Q

what is detritus

A

not consumed (leaves)

103
Q

why total energy declines as you move up trophic levels from producers to tertiary
consumers.

A

At each level energy is lost to

-non-consumed tissue (detritus)
-non-digestiable tissue (egested)
-respriation

104
Q

egested

A

non digestiable tissue

105
Q

trophic pyramid

A

a chart composed of stacked rectangles representing the amount of energy or biomass in each trophic group

106
Q

pyramid of energy

A

a trophic pyramid that displays the total energy existing at each trophic level

107
Q

pyramid of biomass

A

a trophic pyramid that represents the standing crop of organisms present in different trophic groups

108
Q

Ecological efficiency

A

the percentage of net production of one trophic level compared to the next level down

109
Q

Assimilation efficiency:

A

the percentage of consumed energy that is assimilated (and then goes to either respiration OR growth and reproduction)

110
Q

consumption effciency

A

the % of energy or biomass in a trophic level that is consumed by the next higher trophic level

111
Q

net production efficency

A

the % of assimilated energy that is used for growth and reprocuction

112
Q

flow of NUTRIENTS

A

-flow through ecosystems in cycles

-not lost, recycled

113
Q

what is nitogen used for?

A

amino acids, nucleic acids

114
Q

What is phosphorus used for?

A

bones, scales, teeth, DNA, RNA, ATP

115
Q

What is sulphur used for

A

proteins (cysteine)

116
Q

what is potassium used for

A

enzymes

117
Q

what is calcium used for

A

bones + teeth, muscles contraction

118
Q

what is magnesium used for

A

many enzymes, chlorophyl

119
Q

what is iron used for?

A

hemaglobin, needed to make chlorophyll

120
Q

The hydrologic cycle

A

the movement of water through ecosystems and atmosphere

121
Q

The hydrologic cycle main processes

A

evaporation:
transpiration:
precipitation:
infiltration:
run-off:

122
Q

evaporation:

A

solar energy heats water, changes to gas

123
Q

transpiration:

A

water vapour from plants

124
Q

precipitation:

A

returns to land (rain)

125
Q

infiltration:

A

percipitates through soil into the ground water (eventually to ocean

126
Q

run-off:

A

runs off land surface into lakes/rivers/oceans

127
Q

How does human activity affect
the hydrologic cycle?

A

1) pave surfaces

2) global warming

3) use ground water for irrigation

4) use freshwater for households

5) destroy forests/grasslands

128
Q

How does paving surfaces affect the hydrologic cycle

A

increases run-off, decreases infiltration

129
Q

How does global warming affect the hydrologic cycle

A

increased evaportaion, more precipitation

130
Q

How does using ground water for irrigation affect the hydrologic cycle

A

depletes groundwater

131
Q

How does using freshwater for households affect the hydrologic cycle

A

irrigation, industry, humans use ~50% of accessible freshwater run-off

132
Q

How does destroying forests/ grasslands affect the hydrologic cycle

A

less transpiration, more run-offs

133
Q

Processes that add carbon dioxide to the
atmosphere:

A
  • respiration

-fires + volcanoes (compustion)

-combustion of fossil fuels

134
Q

combustion of fossil fuels =

A

CO2

concentraion is 30% higher than preivous maxiumum levels

135
Q

CO2 absorbs infrared radiation, reflects back to earth =

A

warmer “greenhouse effect”

136
Q

The Nitrogen Cycle:

A

biggest pool of N = N2 in atmosphere

137
Q

N-fixation:

A

the process of converting N in atmosphere into forms that producers (plants) can use

138
Q

N-fixation is done by

A

some cyanobacteria

some freeliving bacteria

some mutualistic bacteria

also lightning combustion and fertilizer production

139
Q

How does human activity affect
the nitrogen cycle? N-fixation:

A

N2 = NH3 (ammonia) = NH4+ (ammonium)

or

NH3 = NO3- (nitrate)

140
Q

N-fixation by humans GREATER
than ALL natural fixation !!!!! why?

A
  • more N as ammonium or nitrate
    available to plants
141
Q

What is the result for plant communities????

A

-higher productivity

-sometimes = lower species richness= favouring dominant competitors

142
Q

nitification

A

the final process in the nitrogen cycle, which converts ammonium to nitrite (NO2) , and then from nitrite to nitrate (NO3-)

143
Q

The phosphorus cycle:

A

-no gas phase

major source of P = rocks

144
Q

weathering:

A

carbonic acid in rainwater + organic acids produced by decomposition of plant litter react with minerals in the bedrock and release elements

145
Q

How does human activity affect the phosphorus cycle?

A

-added phosphates to detergents

  • fertilizer

-ending up in streams, rivers, lakes

-caused ENTROPHICATION

146
Q

EUTROPHICATION:

A

: an increase in the productivity of aquatic ecosystems

more N + P = more algae growth = increase algae dying = increase bacteria that eat deade algae (respiring) = decrease in O2 = DEAD ZONE

147
Q

mineraliazation

A

the process of breaking down organic compounds into inorganic compounds

148
Q

denitrification

A

the process of converting nitrates into nitrogen gas

149
Q

cultural eutophication

A

an increase in the productivity of aquatic ecosystems caused by human activities

150
Q

watershed

A

an area of land that drains into a single stream or river

151
Q

The Breakdown of Organic matter

A

-weathering is very important and very slow
therefore, really important to recycle nutrients in dead organic matter
- mainly fungus, bacteria, invertebrates

152
Q

The Breakdown of Organic matter
(in terrestrial ecosystems) Main processes:

A

1) Soluble minerals and small organic compounds leach out of detritus
-ex salts, sugars, amino acids

(2) large detritivores consume organic matter
- millipedes, wood lice, earthworms

(3) fungi break down woody components (can penetrate tissues)

(4) bacteria decompose almost everything (even LIGNIN!)
- about 90% of plant matter produced each year is NOT consumed by herbivores

153
Q

The rate of decomposition depends on:

A

1) environmental conditions
-temp - hotter = faster chemical rxn
-precipitaion- more water = more leaching

2) the chemical composition of the material
- more ligin = slower decomp

3) what decomposers are present!
- earthworms

154
Q

tropical forest:

A

70% decomposition of Inga tree leaves in 250 days

155
Q

boreal forest:

A

70% decomposition of aspen leaves in 12 YEARS !!!!

156
Q
A
157
Q

Habitat heterogeneity

A

variety in habitat conditions

ex- soil types, topography, height of vegatation, age of forest, vegeatation types

region 1 = 16 vegatation types
region 2 = 5 vegatation types

region 1 has more varity = more heterogeneity

158
Q

Why does it promote higher species richness?

A

-different species are adapted to different habitat conditions (niche) therefore lots of different habitat conditions - lots of different speices

159
Q

Often, habitat heterogeneity is caused by

A

things that happened in the past

160
Q

Legacy effects:

A

when something that happened in the past is still affecting ecological communities

can happen naturally or by humans

161
Q

example of legacy effect

A

Fire history: different regions last burned at different times = forests of different ages

162
Q

landscape ecology

A

the field of study that considers the spatial arrangement of habitats at different scales and examines how they influence individuals, populations, communities, and ecosystems

163
Q

Levels of species diversity:

A

Researchers counted # of bird species at 206
sites in Boreal Forest

  • at each site, on average, they found 29 species = local species richness OR alpha diversity
  • total for all sites together = 134
    species = regional species richness or gamma diversity
164
Q

Gamma diversity or regional species richness

A

ALL the species that live in the region

the number or species in all of the habitats that comprise a large geographic area

165
Q

local species richness OR alpha diversity

A

the subset of all those species that can live at that particular site

the number of species in relatively small area of homogeneous habitat, such as a stream

166
Q

Beta diversity:

A

number of species that differ between 2 habitats (number not shared)

167
Q

regional species pool

A

the collection of species that occurs within a region

168
Q

species sorting

A

the process of sorting species in the regional pool among localities according to their adaptions and interactions

169
Q

species- area curve

A

a graphical relationship in which increases in area (A) are associated with increases in the number of species (s)

170
Q

Why do we find this consistent species-area relationship? Potential explanations:

A

(1) Larger areas tend to have greater habitat heterogeneity
-=more niches = more species

(2) Smaller areas have smaller populations, and smaller populations
=higher extinction rate

(3) sampling phenomenon

171
Q

stepping stones

A

small intervening habitat patches that dispersing organisms can use to move between large favourable habitats

172
Q

equilibrium theory of island biogeography

A

a theory stating that the number of species on an island reflects a balance between the colonization of new species and the extinction of existing species

173
Q

Habitat fragmentation:

A

1.The total amount of habitat goes… down

2.The number of patches of habitat goes… up

3.The total length of edges goes… up

4.The distance between patches goes… up = increased isolation

174
Q

More edges =

A

more ecotones

ecotones often support a higher number of species

175
Q

Conditions at forest edges…

A

more sun can get in, therefore… more light, warmer, less mositure

176
Q

IS FRAGMENTATION BAD???

A

1) LOTS of evidence – strong species-area relationship, more habitat = more species

2) DEBATEABLE – if choosing between one patch and several patches that add up to the same total amount of habitat, 1 patch is not always the best option

177
Q

continential drift

A

the movement of landmasses across the surface of earth

178
Q

PERFECT NESTEDNESS

A

saving the most species to save biodiversity

179
Q

NOT PERFECTLY NESTED

A

When the many small has more different species than the one big region

180
Q

S =

A

= equilibrium number of species

181
Q

largest S =

A

large islands that are close to the mainland

182
Q

Patterns of species richness in North America:

A

On a global scale, biodiversity is highest near the equator and declines toward the poles

183
Q

why would canada have more biodiversity?

A

-canada was glaciated in the past

-each time glaciers retreat, plants have to recolonize

-each time glacier advances - disperse or go extinct

-cape floristic region = stable climate

184
Q

Where should we protect biodiversity?

A

assumption: we cannot protect EVERYTHING EVERYWHERE

  • not enough $$$
  • need some land for cities, farms, mines
    Therefore, we need to prioritize.
185
Q

Where should we protect biodiversity? Options:

A
  • places that have the most total number of species
  • places that have the most endemic species
  • places that have the most endemic species and highest degree of threats
186
Q

BIODIVERSITY ‘HOTSPOTS’:

A

regions with at least 1,500 endemic plant species AND at least 70% loss of habitat

187
Q

BUT Canada is important for other reasons:

A

2 in area marine shelf

1 in intact wilderness

2 in freshwater

188
Q

Why do we value biodiversity?

A

(1) Instrumental value

(2) Intrinsic value

189
Q

Instrumental value

A
  • different species provide products (lumber, food, medicine), services (flood regulation, water purification), cultural benefits (recreation, arts)

a focus on the economic value a species can provide

190
Q

(2) Intrinsic value

A

species are inherently valuable, they deserve to exist just as we do, and we have a moral obligation to protect them – even if they provide NO benefit to us

a focus on the inherent value of a species, not tied to any economic benefit

191
Q

How many species live on planet
Earth???

A
  • many not described yet
    -estimated total 3-100 million
    -most scientists estimate ~10 million
192
Q

provisioning services

A

benefits of biodiversity that humans use, including lumber, fur, meats, water, crops, fibre

193
Q

regulating services

A

benefits of biodiversity that include climate regulation, flood control, and water purification

194
Q

cultural services

A

benefits of biodiversity that provide aesthetic, spiritual, or recreational value

195
Q

supporting services

A

benefits of biodiversity that allow ecosystems to exist, such as primary production, soil formation, and nutrient cycling

196
Q

Extinction:

A

has been occurring throughout the history of life on Earth

197
Q

Mass extinction event =

A

least 75% of all existing species go extinct within a 2 million year period

-most recent (dinos)
-after mass extinctions, more species evolve

198
Q

It can be hard to assess how a species is doing

A
  1. it has to be known/named
  2. it has to be studied well enough over a long enough time period to determine whether it is declining or not
    • therefore takes time, expertise and money
199
Q

IUCN =

A

international union for the conservation of nature
-redlist
- founded in 1948
- gathers data on the status of species

200
Q

Biodiversity includes…

A

diversity of SPECIES

GENETIC diversity

201
Q

GENETIC diversity = diversity within species

A

provides ability for a species to adapt to different conditions
- ex: new disease

202
Q

The biggest cause of recent losses of biodiversity =

A

HUMANS

203
Q

The biggest cause of recent losses
of biodiversity = HUMAN

A

(1) HABITAT LOSS

(2) Overharvesting

(3) INTRODUCED SPECIES

(4) POLLUTION

(5) GLOBAL CLIMATE CHANGE

204
Q

(1) HABITAT LOSS

A

35% of global land area now used for
crops or pasture

  • 10 million hectares of tropical forest is
    logged every year 1/6 of alberta
205
Q

Even if a remaining piece of oldgrowth forest is protected from logging, some species that live in it may still go extinct. WHY?

A

-small area supports smaller populations

-smaller populations are more susceptible to extraction

-time lags

206
Q

(3) INTRODUCED SPECIES

A

domestic cats and animals

207
Q

(5) GLOBAL CLIMATE CHANGE

A
  • increasing temperature
  • has not caused widespread extinction YET
  • but: species will have to shift their distributions
208
Q

BIOMAGNIFICATION:

A

the process by which the concentration of a contaminant increases as it moves up the food chain

209
Q

biotic homogenization

A

the process by which unique species compositions originally found in different regions slower becomes more similar due to the movement of people, cargo, and species

210
Q

What can be done???

A

1 major thing is HABITAT PROTECTION

211
Q

goal:

A

protect enough habitat to support the minimum viable population (MVP)

= the smallest population size that will allow a species to persist even with environmental variation

212
Q
A

Eco (4 decks)

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