Ecology Flashcards
1
Q
What is ecology?
A
the science of how organisms interact with each other and their environment
2
Q
Biotic vs. abiotic factors
A
biotic: living
abiotic: non-living
3
Q
Ecosystem services
A
services we can gain from around us
4
Q
What approaches does modern ecology use?
A
- observational
- experiments
- data analysis + statistical modelling
- community engagement + diverse knowledge systems
5
Q
What is distribution and what do ecologists observe about it?
A
how a population/ species is spatially arranged. Ecologists observe limits to and changes in distributions
6
Q
How do ecologists examine abundance?
A
changes in abundance and whether populations are growing or shrinking
7
Q
Why is ecology important? (NO wrong answer)
A
to create a sustainable world, to reverse climate change and stop it, to prevent mass extinction and biodiversity loss
8
Q
How do ecologists address conservation and biodiversity problems?
A
evaluating effectiveness of conservation strategies
ex: do marine protected areas work?
9
Q
How do ecologists manage environmental issues?
A
by evaluating the consequences of human activities
ex: what effect is climate change having on biodiversity?
10
Q
How are wildlife and resource management problems addressed?
A
by evaluating the effectiveness of management strategies
ex: when does fishing become overfishing?
11
Q
What role do ecologists play in pest control?
A
they create strategies for reducing crop loss
ex: why do some insects get out of control?
12
Q
How are ecologists involved in human health?
A
they examine how diseases are spread through animals
ex: what is the role of climate and how will climate change affect pathogen spread?
13
Q
What are the levels of ecological study? (from smallest to biggest)
A
- organism
- population
- community
- ecosystem
- landscape/ seascape
- global
14
Q
What has the most significant influence on the distribution of organisms?
A
climate
15
Q
What is climate?
A
the long-term prevailing weather condition in a given area
16
Q
What makes up a climate?
A
- temperature
- precipitation
- sunlight
- wind
- seasonal patterns
17
Q
What determines climate? (main climate determinants)
A
- input of solar radiation
- Earth’s movement in space
18
Q
What determines climate? (climate modifiers)
A
- large bodies of water
- mountain ranges
- greenhouse gases
19
Q
How does solar radiation determine climate?
A
more direct sunlight results in more heat and light (i.e. equator is hotter than the poles)
20
Q
Why are deserts mostly found at 30 degrees North/South?
A
descending air from equator heats up again and evaporates moisture resulting in a dry and hot climate
21
Q
Why does the equator have high precipitation?
A
solar radiation drives evaporation, the rising moist air cools and releases moisture as precipitation
22
Q
How do large bodies of water and mountains modify climate?
A
- cool, moist air flows from offshore onto land
- air warms as it crosses land
- air cools as it travels up mountain and releases moisture as precipitation
- dry air picks up moisture on other side of mountain
23
Q
How do greenhouse gases modify the climate?
A
greenhouse gases (e.g., CO2 and methane) trap heat inside the Earth’s atmosphere
24
Q
What characterizes a biome?
A
its climatic features and predominant vegetation
25
What is a climograph?
a representation of annual mean temperature and annual mean precipitation
26
Northern coniferous forest (boreal forest/taiga)
- largest terrestrial biome
- 30-70 cm annual precipitation
- cold winters, hot summers
- dominated by cone-bearing trees
27
What drives transitions among forested biome types?
temperature and precipitation
28
What is disturbance?
an event that removes individuals from a population
29
What is two examples of disturbance?
1. Large animal grazers
2. Fire
Both events remove plant life. W/o them, Savannas would be Woodlands
30
What drives the transition from forested to non-forested biomes?
precipitation and disturbance
31
What is happening to biomes and ecosystems as temperatures rise?
boundaries are shifting towards the poles (cooler areas)
32
What are range shifts?
when a species shifts its range to stay within their climatic niche
- generally from equator -> poles
- avg. 17km/decade (terrestrial) and 72km/decade (marine)
- deeper (marine) and higher (mountains)
33
Why will some species be unable to shift to a more suitable temperature?
1. suitable habitat not available
2. species may not migrate quick enough to track suitable climate
34
What limits distributions?
1. dispersal: organism didn't get there
2. abiotic factors: temperature, moisture, salinity (oceans), oxygen (oceans)
3. biotic factors: resources, predation, competition, disease
35
Impact of climate on humans
the countries who are contributing the least to climate change are also the most vulnerable
36
What are some threats to biodiversity?
- habitat destruction
- overexploitation
- pollution
- invasive species
37
Population
group of individuals of the same species living in the same area sharing similar resources that interact and breed
38
Population ecology purpose
to measure population size, model population growth, create life history strategies, examine population diversity
39
What is a census?
measuring ALL individuals in a population
40
Why is a census disadvantageous?
hard to:
- count a whole population of very small organisms (beetles)
- count individuals in a large area
- count a huge population
41
What are examples of indirect indicators of population size and why are they more useful?
- # of nests, burrows, tracks
- catch per unit effort (CPUE) -> fisheries
- mark-recapture methods
these methods require less resources, less time, and less money
42
What was observed in the catch per hundred hooks example?
the number of catches decreased globally as time went on, the region of fishing expanded
red regions -> blue regions -> new red regions -> blue regions
43
How does the mark-recapture technique work?
a number of organisms from a population are captured and marked (tag, paint, etc.) and then are released. At a later time, another group is captured and researchers count how many organisms are marked out of the group. The number marked in the second group compared to those unmarked is proportional to the total number marked compared to the whole population
44
What assumptions are made when using mark-recapture?
1. marked and unmarked have the same probability of being captured
2. marked individuals have completely mixed back in with population (i.e. they aren't off in their own group)
3. no individuals born, die, immigrate/emigrate during sampling interval
45
What equation is used for mark-recapture?
x/n = s/N
where:
x = total number of individuals marked in second sample
n = number of individuals in second sample
s = number marked and released in first sample
N = estimate of population size
N = s*n/x
46
What is the exponential growth model?
dN/dt = rN
where:
dN/dt = rate of change in a population
N = current population size
r = growth rate (larger = faster growth)
47
When does exponential growth occur in a population?
when resources are readily available, not limited
48
What slows population growth rate?
- limited resources
- food and space
- competition
49
What is intra-specific competition?
competition for resources among individuals of the same species
50
Is r (growth rate) dependent on birth and death rates?
Yes, r = b-d
51
How did population density of sea otters impact birth rate?
Population density did not impact birth rate, therefore birth rate is density independent
52
Was pup death rate in sea otters density-independent or density-dependent? Why?
Death rate in sea otters was density-dependent because limited food meant mothers were thinner which resulted in a lower survival rate for pups
53
What is carrying capacity?
represented by K, carrying capacity is the # of individuals of a given population that the environment can support/sustain; birth rate = death rate (intersection of the two lines on graph)
54
What is the logistic growth model (equation and what it means)?
dN/dt = rN((K-N)/K)
where (K-N)/K reduces the rate at which the population grows as N increases
55
Briefly summarize the growth model of the lionfish invasion model
- very successful invasive species
- few natural predators, reproduce quickly
- growth originally followed exponential model when resources were abundant, however it eventually followed a logistic growth rate
55
What is a top-down process?
a given population is regulated by predation from ABOVE them in the food chain
55
What are the three main variables of life history?
- age of first reproduction
- how often organism reproduces
- how many offspring produced per reproductive episode
56
What are the two reproductive strategies and their trade-offs?
- increase offspring size: many offspring, but low survival rate
- provide parental care: few offspring, but high survival rate
57
What are r and K strategists?
r-strategists maximize # of offspring while K-strategists maximize offspring survival
58
What environments benefit r and k strategists?
r: physically harsh and unpredictable environment
K: crowded or competitive, and predictable environment
59
R-strategists are found in what kinds of habitats?
- open/ disturbed: roadsides, lava flows
- temporary: tiny ponds, cropland
- unpredictable: deserts (rain), grasslands (fire)
60
K-strategists can be found in what types of habitats?
- permanent: rainforest, open ocean, large lakes
- crowded: resources limited
61
What defines r and k strategists? (what kind of species??)
r: invading species, colonizing species
K: strong competitors
62
Young vs. adults: r and K strategists
r: high birth rates, low survival in young, higher in adults
K: low birth rates, high survival in young, lower in very late life
63
Why is population diversity important to sustain?
different populations have different genes, behaviours, local adaptations, stress responses, and ecosystem services
translocating individuals from one population to another creates diversity
64
What is a community?
a group of populations of different species that live close enough to interact
65
What are the different types of species interactions? (think +/-)
- competition (-/-)
- mutualism (+/+)
- commensalism (+/0)
- parasitism (+/-)
- predation (+/-)
- herbivory (+/-)
66
What is competitive exclusion?
when one species in a competition interaction outcompetes the other species
- species must occupy slightly different niches in order to coexist
67
What is an ecological niche?
the position of a species within an ecosystem
- conditions necessary for its survival
68
Realized vs. fundamental niche
realized: the 'observed' niche that it occupies in the wild
fundamental: the conditions in which it CAN survive and reproduce
69
What is character displacement?
the evolution of differences in morphology and resource use as a result of competition
ex: lec #3 - threespine sticklebacks
70
What is symbiosis?
a close interaction between two organisms of different species
- mutualism
- commensalism
- parasitism
71
Direct vs. indirect transmission of pathogens
direct: pathogens move from one host to the next
indirect: pathogens use another organism (vector) to help them move
72
What is brood parasitism?
when an organism passes on the cost of raising their offspring to another individual/host
- can be intra or interspecific
73
What is a focal species?
a species that plays a disproportionate role in the food web
74
What is a dominant species?
a species with a high biomass in the ecosystem (abundance and mass)
75
What do ecosystem engineers do? (ex: beavers)
they alter the physical environment
76
What is a keystone species?
a species that has low biomass and abundance, but still plays a crucial role in the food chain (i.e., usually top predators)
77
What is top-down control?
higher trophic level(s) reduce the abundance or biomass of lower trophic level(s)
78
What is a trophic cascade?
the impact of top predators extends to lower trophic levels
79
How is a sea otter an example of a keystone species?
while they don't have a large biomass, they still have an impact on community by reducing the number of herbivores which increases the amount of kelp
80
What is a regime shift?
an abrupt shift to a different and persistent community (i.e., hard to reverse)
81
What causes regime shifts?
- removal of keystone species
- arrival of disease
- climate change
- nutrient inputs
82
What is bottom-up control?
when a lower trophic level controls abundance or biomass of a higher trophic level
83
What is biodiversity?
the variability among living organisms and the ecological complexes of which they are a part; diversity WITHIN species, BETWEEN species, and of ecosystems
84
What is species richness?
number of species present in a community (nothing to do with the diversity of a community!)
85
What is the latitudinal gradient in species richness?
as the latitude spreads from 0, richness declines
86
Why does the latitudinal gradient in species richness exist?
- the equator was the origin of life, therefore species have had more time to diversify there
- historical adaption to tropical environments = less species at higher latitudes
- higher and more stable temperatures = shorter generation times and mutation rates
- stable environment conditions = low extinction rates
87
What is the best level of disturbance for species richness?
intermediate disturbance (too low and too high lowers species richness)
88
What are the main drivers of biodiversity decline?
- climate change
- pollution
- invasive species
- overexploitation
- habitat destruction
89
Biodiversity is tied to ____ ____, which are benefits humans obtain from ecosystems
ecosystem services
90
Ecosystem
organisms and abiotic environment
91
How is ecosystem function defined?
interactions between species and energy and nutrient flow
ecosystem function is how an ecosystem "works"
92
What are the components of an ecosystem?
- primary producers: autotrophs
- primary consumers: heterotrophs
- secondary consumers: heterotrophs
- decomposers: heterotrophs
- detritus: dead organisms
93
Ecosystem energetics
- ecosystems and life are powered by the sun
- primary producers capture radiant energy (sun) and store as chemical energy
- ecosystems transfer chemical energy through consumption (transfer to consumers) and death (transfer to detritus)
- ecosystems lose heat through respiration
94
What is the one-way energy flow in ecosystems?
energy enters as radiant energy, stored as chemical energy, and leaves as heat energy
95
Nutrient flows
- circular flow of nutrients: nutrients are mostly retained
96
Why are decomposers important to nutrient cycling?
they obtain chemical energy and nutrients from detritus and return some of the nutrients to the physical environment
97
What is the carbon cycle in an ecosystem?
plants get CO2 from the atmosphere and convert it into organic carbon. Org. C is then transferred among organisms and returned to the physical environment as CO2 through respiration
98
Where is carbon stored in the physical environment?
- mostly in rocks and sediments
- ocean
- atmosphere
- living organisms
99
How are humans altering the carbon cycle?
- fossil fuels: long-term carbon being stored underground is released into atmosphere
- destruction of habitat: lowering # of primary producers to convert CO2 into Org. C
100
What are the effects of climate change?
- increasing temperatures
- melting sea-ice
- extreme events (weather)
- changes in precipitation
- changes in ocean circulation
101
How is coral impacted by climate change?
coral bleaching
- warming water is resulting in corals losing their symbiotic algae
- repeated bleaching can permanently alter coral community
102
Explain ocean acidification
more carbon dioxide in the oceans lowers the pH level and carbonate ion concentration, which is resulting in calcifying organisms having trouble building and maintaining calcium carbonate skeletons
103
How do bacteria drive the nitrogen cycle?
two types of bacteria:
1) N-fixation bacteria convert N2 -> NH4+
2) nitrification bacteria convert NH4+ -> NO3- which is the form plants use
3) denitrification bacteria convert NO3- -> N2 to be put back into the environment
104
What are the consequences of applying N fertilizer
long-term impacts of excessive nitrogen inputs:
- high levels of nitrate in soil water (can be toxic)
- pollution of aquatic ecosystems
105
What is eutrophication (in coastal marine environments)?
excessive primary production due to overload of nutrients
106
How do dead zones form?
1. freshwater run-off gets heated in the spring creating a barrier between the salt water and oxygen from the air
2. N and P from run-off create algae blooms. When algae die, they sink into the salty water and decompose, using up oxygen from the deeper water
3. the deeper water becomes a dead zone as it is starved of oxygen. Fish either avoid the area or die in massive numbers.
107
What are two reasons that an ecosystem might be 'unhealthy'
if it's less likely to:
- obtain or transfer energy
- cycle or retain nutrients
108
Why should we care about ecosystem health and function?
1. feeding ourselves
2. natural ecosystems
3. we are changing the rates
- deforestation
- use of fertilizers
- greenhouse gas emissions and climate change
109
What are the 3 measures of ecosystem function?
1. rate of primary production
2. rate of secondary production
3. rate of decomposition
110
What is net primary production?
the rate that plant biomass increases in an ecosystem
111
What limits net primary production?
terrestrial ecosystems:
- temperature
- moisture
- soil nutrients
marine ecosystems:
- light (depth)
- nutrients
112
What equation represents net primary production?
NPP = GPP - R(a)
where,
GPP = gross primary production (total light energy captured by plants)
R(a) = autotrophic respiration (energy lost due to plant respiration)
113
What is net ecosystem production?
energy (biomass) accumulated in all ecosystem components (per unit time)
- plants capture energy
- energy stored as biomass in all organisms
- heat energy lost from all organisms
114
What equation represents net ecosystem production?
NEP = GPP - R(t)
where,
R(t) = total respiration (heat lost from all components)
NEP > 0: ecosystem biomass increasing
NEP < 0: ecosystem losing biomass
115
What does a positive net ecosystem production mean?
- ecosystem biomass is increasing
- ecosystem absorbs more CO2 than it releases
- helps lower atmospheric CO2 (climate change)
116
Behaviour and natural selection
more appropriate behaviour = passing on more genes = more likely to survive + more likely to produce offspring
117
What are the types of mating systems?
- monogamous: single pair bond
- polygamous: one individual mates with several of the other sex
- promiscuous: no strong mating bonds
118
What do ecologists look at when they don't know why a species behave a certain way? Give an example from lecture
environmental conditions
ex: female spotted sandpipers do not look after their young because
1) there is enough food for one parent to raise chicks
2) they only lay 4 eggs at a time -> want more in a season
3) long breeding season = more time to have many clutches of eggs
119
What are the 4 types of social behaviour?
- cooperative (+/+)
- altruistic (-/+)
- selfish (+/-)
- spiteful (-/-)
120
What are examples of cooperative social behaviour and in what environment would we see this behaviour?
- hunting
- defense
environment: lots of available resources
121
What is an example of selfish social behaviour? What environment is this most common in?
territoriality
environment: limited resources -> competition
122
Why do animals participate in altruistic behaviour?
inclusive fitness: total effect on number of genes passed on
- produce offspring
- aid relatives to produce more offspring!!! (this one)
123
What is kin selection?
selection for an act that enhances relative's reproductive success
124
What is Hamilton's rule (altruism)
natural selection will favour an act of altruism if:
C < r*B
C: cost to altruism (lost reproduction)
B: benefit to recipient (increased reproduction)
r: relatedness (shared genes)
125
What is an example of spiteful behaviour and why is it bad for both actor and recipient?
ex: going around and killing a bunch of animals
why: it wastes a lot of energy for no reason
126
When do animals participate in spiteful behaviour (rearranged Hamilton's rule)
when C < (r < 0) * (B < 0)
C: cost to actor
R < 0: negative relatedness
B< 0: negative benefit to recipient
127
What are the benefits and costs of animals living in groups?
benefits:
- cooperative feeding
- defense of group
costs:
- disease/parasites
- restricted reproduction
group living occurs only when b > c
128
What is a eusocial society?
a group that divides labour and behaviour into reproductive and non-reproductive groups
benefits of remaining in group must outweigh independent reproduction
129
What is conservation biology?
applying ecological theory to aid in biodiversity conservation
goal: slow, halt, or reverse the loss of biodiversity
130
What are the 3 components of biodiversity?
- variation within species:
- genetic diversity
- population diversity
- variation between species:
- species richness
- variation among species aggregations:
- community diversity
- ecosystem diversity
131
What are some threats to biodiversity?
- habitat-loss
- overharvesting
- pollution
- climate change
- introduced species (invasive)
132
Extirpated vs. extinct
extirpated = gone from ONE specific region
extinct: gone from ALL regions
133
What are the categories of the IUCN Red List?
- extinct (EX)
- extinct in wild (EW)
- critically endangered (CE)
- endangered (EN)
- vulnerable (VU)
- least concern (LC)
- data deficient (DD)
- not evaluated (NE)
134
What are the 5 criteria of the IUCN Red List categories?
- population size reduction
- geographic region
- small population size and decline
- very small or restricted population
- quantitative analysis (risk of future extinction)
135
What is SARA (species at risk act)?
a national (Canada) legislation to protect species in Canada at risk of extinction
prohibits:
- killing or disturbing species
- destroying or disturbing its habitat
requires:
- recovery strategies, and management plans to stop and reverse species decline
136
Why are small populations more likely to go extinct?
stochasticity- chance events
genetic problems can arise in small populations
137
How can genetic problems lead to extinction?
genetic drift:
- less able to adapt to changing environment
inbreeding:
- expression of deleterious alleles
- reproductive problems
138
What can be done to protect small populations from extinction?
- habitat restoration
- prevent further habitat fragmentation
- develop habitat corridors to aid dispersal and gene flow
- genetic rehab through translocations
139
What are some species-level solutions to extinction?
- limiting sources of mortality
- protecting or improving habitat
- translocation
- captive breeding and reintroductions
- storage of genetic material
- education and community involvement
140
What is step 1 of creating a protected area?
define goals:
- biological (what to protect?)
- human (why protect it?)
- intrinsic value
- resource management
- economic opportunity
141
What is an MPA?
a 'marine protected area' is any coastal or open ocean area in which certain uses are regulated to protect natural resources, biodiversity, or cultural resources
142
Explain the MPA guide
look at lecture 7 - this is too hard to write out
