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ENVR 202 > Lecture 18-20 > Flashcards

Lecture 18-20 Flashcards

1
Q

When did food productions begin in human civilization?

A

Food production = deliberate raising of animals and cultivation of cereal grasses and edible root plants

12 000 years ago

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2
Q

What is domestication?

A

A change in the gene pool of a plant or animal resulting from a coevolutionary process

Example: wolves –> dogs

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3
Q

How can domestication occur?

A

Through artificial selection: humans manipulate plant/animal breeding to selectively develop particular phenotypic traits by choosing which males and females will reproduce or allowing reproduction/survival to occur in a controlled envr

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4
Q

What kind of traits are being selected in modern days to survive farm conditions?

A

Ability to survive stress (de-beaking, crowded conditions, caging)

High production (egg, meat, milk)

Ability to survive food (e.g. cows fed corn –> not their natural diet)

Can select for disease resistance but also increased reliance on anti-parasitics, antibiotics, etc. to control disease caused by conditions

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5
Q

Which traits are selected for today in plants?

A

Resistance to herbicides
Production of non-viable seed (so farmers dependent on yearly seed purchases)
Uniform germination and maturation times (so they can all be harvested at once)
Unifrom grain size
Disease and pest resistance
High yield
Herbicide tolerance
Food quality (protein content, flavour, etc.)
Storage quality

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6
Q

What is the result to modern day selection in plants?

A

Only the highest yield plants and animals persist to retain financial solvency

Many plant species are genetically identical

Only the highest yield species persist

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7
Q

How are modern crops experiencing genetic bottleneck?

A

Crop plants are often extensively inbred and not allowed to reproduce sexually in the field, severly limiting their gene pool and reducing variation needed to adapt (e.g. to climate change)

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8
Q

What percentage of canola growth in Canada is GMO?

A

95%

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9
Q

How many GMO food crops are sold in Canada?

A

9

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10
Q

What are GMO?

A

Genetically modified organism

Creates combination of plant, animal, bacteria and virus genes that do not occur in nature or through traditional crossbreeding methods

Traits added: herbicide resistance (weed control), pest resistance, reduced browning

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11
Q

Are GMOs a short-circuit of evolution?

A

Actually, genges move between kingdoms in nature quite regularly

But there is potential for hybridization

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12
Q

What is the result of rapid evolution of antibiotics?

A

Antibiotic use is widespread in agriculture for increasing yield and enabling high density

This results in rapid resistance, significant concerns about loss of effectiveness and spread

Superbugs can arise, resistance to pesticides

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13
Q

What are some specific ways that agriculture has changed the planet?

A

Ecosystem displacement/fragmentation

Source of CO2, NOx and CH4

Shifts in animal biomass (livestock now vastly outweigh all wild mammals)

Eutrophication (nutrient enrichment)

Pesticide bioaccumulation

Erosion

Freshwater depletion

Salinization

–> all of these changes modify the selection pressures, gene flow and genetic diversity of populations

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14
Q

What are the impacts of ecosystem displacement/fragmentation?

A

37% of earth is now used for agriculture of some kind (the only two large areas that aren’t are the world’s two largest rainforests that are under significant threat)

Removal of entire tracts of ecosystem

Agriculture land use is a huge driver of deforestation (causes drought, fire, disease)

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15
Q

What are the impacts of agriculture of GHG emissions?

A

Come from enteric fermentation (livestock), manure, fertilizer, rice paddies

Agriculture management (tillage, grazing) also cuases loss of stored C in soils

Clearing peatland/wetlands also increase CO2 emissions a lot

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16
Q

What is the impact of agriculture on eutrophication?

A

A lot of fertilizer runoff from agriculture (contains N and P runoff)

Goes into air or water

Excess nurients causes algal blooms, growth of parasites, kills fish

Human health issues

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17
Q

What are the impacts of pesticides?

A

Many pesticides do not break down, and are magnified up the food chain (bioaccumulation)

Many non-target effects (DDT on bird eggs, fish kills)

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18
Q

What is the impact of erosion?

A

Heavy grazing, ploughing break up soil aggregates and remove stabilizing vegetation

Result can be massive loss of topsoil

Depletes soil carbon stocks

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19
Q

How is freshwater impacted by agriculture?

A

Agriculture is majorly reshaping hydrology via dams and aquifer depletion

Water likely to be a major dirver of international conflict in the decades to come

Ex. the colorado river –> now rarely reaches the sea, every last drop of its water fully overallocated, no delta habitat (pop. of fish, shrimp, and sea mammals have seen dramatic decline)

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20
Q

What are the impacts of salinization?

A

Uplift of water from deep basins has brought subsurface salts to the surface

Land now very inhospitable since high salt content prevents vegetation growth

21
Q

How has agriculture changed human society?

A

Allowed permanent settlements: affected almost all aspects of society and the economy

Greater amounts of food, more reliable

Storage: delayed-return rather than immediate return

Support of non-producers
- specialization and division of labour

Sedentism (staying in one place)

Great pop. density

–> this all lead to disease, land ownership, land degradation

22
Q

How has agriculture changed our bodies?

A

The advent of agriculture lead to a decline in general and oral health due to an increase in carbohydrates, softer calorie-dense foods, reduced diet variety
- This lead to reduced skeletal robustness, shorter stature, smaller jaw, dental decay and malocclusion

Small mobile populations gave way to large settlements, with close proximity of humans and animals. Sanitation was poor
- Zoonotic diseases: influenza, smallpox, measles, tuberculosis
- Communicable diseases: the above, plus things like cholera

Evidence for changes in areas of the genome associated with immunity, lactose tolerance, digestion, pigmentation

23
Q

What are some ways to improve agriculture going forward?

A

Preserving the gene pool

Agroecology

24
Q

What are the main 5 global drivers of change?

A

Climate change
Habitat loss
Overexploitation
Pollution
Invasive species

25
Q

What are invasive species?

A

A non-indigenous species whose introduction does or is likely to cause economic or environmental harm or harm to human health

Causes damages by changing biotic interactions

26
Q

What is the societal relevance of invasive species?

A

Major cause of biodiversity loss, physical changes, industrial impacts (economic cost), aesthetics (defoliated forest), property values

27
Q

What are the 5 processes of a species invasion?

A

Source location of species

Transport/introduction

Establishment

Spread

Impact

28
Q

What are some examples of pathways of invasion?

A

On purpose: commerce in living organisms, aesthetics, food, livestock, pets, biological control, etc.

Transport related: shipping cargo, travelers in baggage, in wood, on planes/boats, ballast water, canals, etc.

The more number

29
Q

What are some common traits of invasive species?

A

Generalists (eating a lot of thigns), high tolerance for different environmental conditions, phenotype variations

30
Q

What are common traits of invaded ecosystems?

A

Islands/lakes –> relationship between diversity and size

Smaller areas

31
Q

How were zebra mussels introduced? What are their impacts?

A

Introduced through ballast water discharge

They invade pipes, and suffocate other mussels/organisms

32
Q

How do invasive grasses promote a positive feedback loop?

A

Introduction of highly flammable plants increase wildire risk –> more fires –> envr becomes more dry –> drier environments are more prone to fires –> promotes the growth of invasive species

33
Q

What are general policies/management options for each process of an invasion?

A

Species in pathway: prevention – > reduce species in pathways, institute risk screening

Transport: early detection, rapid response –> monitor for early invasions

Establishment: eradication –> provide authority and funding for eradication and control programs

Spread: control and slow the spread –> fund slow-the-spread programs

Ecological, human health, or economic impact: human adaptation (change behaviour and bear the costs) –> establish national center for invaisce species management

34
Q

What are 4 screening questions that can be used to evaluate invasive species?

A

Is the spcies adapted for aquaculture or ornamental purposes?

Has the species become naturalized where introduced?

Does the spcies have invasive races/varietes/sub-species?

Is the species reproductive tolerance suited to climates in the risk assessment area?

35
Q

What are some ways to control pest management?

A

Manual (traps)

Chemical (herbicides, pesticides)

Biological (natural predators/parasites)

Genetics, mRNA

36
Q

What is biodiversity?

A

The variability of life on Earth

The variability among living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems

37
Q

How does habitat change/loss impact biodiversity?

A

Decreases population sizes –> more vulnerable to extirpation

38
Q

What are some factors that are participating in biodiversity loss?

A

Pollution
Invasive species
Cliamte change
Overexploitation
Habitat loss

39
Q

Why should we care about biodiversity loss?

A

Ethics/value of life

Medical

Ecosystem services
- direct (resources such as food)
- indirect (envr. modification, coral reefs)
- lifestyle (recreation)

Culture

40
Q

Break down total economic value in use value and non-use value

A

Use value:
- Direct use value: provisioning services, cultural services
- Indirect use value: regulating and supporting services

Non-use value: provisioning, cultural, regulating and supporting services
- Existence value
- Option value
- Bequest value

41
Q

What are some examples of ecosystem services?

A

Provision of food, fuel and fibre

Provision of shelter and building materials

Purification of air and water

Detoxification of air and water

Stabilization/moderation of climate

Moderation of floods, droughts, temp. extremes, and forces of wind

Generation and renewal of soil fertility, including nutrient cycling

Pollination of plants

Control os pests/diseases

Cultura/aesthetic benefits

etc……

42
Q

What are the consequences of ecosystem services?

A

Promotes the protection of only certain biota

For instance, only 15 plants and 8 animal species supply 90% of our food

Yet biodiversity is about variations

43
Q

How is diversity (species richness) related to biomass? Niche Complementary hypothesis

A

More diversity (not overlapping) increases biomass

However, overlap in niches that they occupy leads to no additional benefit to biomass (biodiversity richness)
- redundacy leads to stability in biomass

Therefore, positive but saturating relation between diversity and biomass (diversity can affect productivity)

44
Q

Is a simple ecosystem with few species at each trophic level better than an ecosystem with multiple species?

A

In the 50s and 60s it was believed that the more pathways there are, the less severe the failure of any one pathway

In the 70s and 80s, it was believed that the more complex systems were less stable

Now, we believe that it depends upon the type of interaction and the strength of the interaction –> it is more nuanced

45
Q

What is the spatial insurance hypothesis?

A

Local diversity may be maintained by immigration from the region which provides the source of variation (species or genetic diversity) that can buffer ecosystem processes against environmental variation
- ability to recover because of the diversity in a spatial context

If many sites are considered (as in a metapopulation) then differences in the timing of biomass fluctations can average out across space; a form of regional stability

46
Q

What happens to number of pests as biodiversity increases?

A

It decreases

47
Q

What are some sources of uncertainty for the links between species richness and ecosystem services?

A

Mismatch between functions measured and final ecosystem service

Mismatch between the study conditions and actual management conditions and service delivery to society

Studies insufficiently comprehensive to assess the different processes underpinning ecosystem-service supply

Simultaneous effects of different components of biodiversity (richness, composition, functional diversity)

Confounding environmental factors other than richness that contribute to effects on service supply

Trade-offs between positive and negative effects of richness of the various functions underpinning service supply

Context-dependent patterns

48
Q

What are some issues with the Endangered Species Act?

A

There is an increasing number of species listed, however it is unclear whether newly listed = newly endangered

Also few removed, unclear whether extinctions, errors, recovered

ENVR 202 (7 decks)

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