EESA01 Lecture8-2011-compressed - EESA01
Lecture
8


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Unformatted text preview: EESA01
Lecture
8
 Food
and
Gene4c
Biodiversity
 November
7,
2011
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 1
 The
“Green
Revolu4on”
 Started
1940’s
 Running
out
of
arable
land
 Solu4on

get
more
out
of
each
unit
of
land
 How?
Via
technologies
that
increase
crop
 yields.
 •  Involves
“intensive
or
industrialized
 agriculture”
 •  Not
always
environmentally
sound
 (surprise?)
 •  •  •  •  Lecture
8
–
Food
and
Gene4c
Biodiversity
 2
 Industrialized
Agriculture
 Several
key
elements:

 1.  Selec2ve
breeding;
monocultures
 2.  Pest
control
 3.  Soil
nutrient
enhancement
 4.  Irriga4on

 5.  Mechanized
plan4ng
and
harves4ng
 6.  Large
energy
(fossil
fuel)
and
material
 inputs
 7.  Use
of
produce
for
other
than
ea2ng
(fuel)
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 3
 Gene4cally
Modified
Food
 •  Involves
splicing
together
pieces
of
DNA
 (genes),
represen4ng
desired
traits
(fast
 growth,
pest
resistance)
from
several
 different
species
into
the
gene4c
makeup
of
 another
species.

 •  Could
solve
a
lot
of
problems,
especially
 nutri4onal
content
and
intensifying
yields.

 •  Unknown
consequences;
a
lot
of
bad
things
 could,
but
have
not
yet
happened.

 Lecture
8
–
Food
and
Gene4c
Biodiversity
 4
 Very
Different
from
Tradi4onal
 Agricultural
Breeding
 •  Tradi4onal
breeding
occurs
within
species
 (intra‐specific)
 –  Like
“selec4on”
in
evolu4on
 •  GM
is
usually
inter‐specific

 –  Like
“muta4on”
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 5
 GM
Foods:
Narrow
but
Widespread
 •  Produc4on
using
GM
by
only
a
 few
na4ons,
but
these
na4ons
 are
the
world’s
major
food
 exporters.

 •  6
countries,
4
crops,
2
traits
 (herbicide
tolerance
and
insect
 resistance)
account
for
99%
of
 global
area
devoted
to
GM
 food
produc4on.

 •  Market
value:
>$6
billion
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 6
 What’s
the
Big
Deal?
 •  Health
consequences?
None
yet
observed.
 •  Interbreeding
with
na4ve/”natural”
species
 
loss
of
gene4c
diversity
 •  “Superpests”
resistant
to
super‐crops
 •  “Superweeds”
from
transfer
between
plants
 •  Precau2onary
principle:
don’t
proceed
un4l
 ramifica4ons
of
an
ac4on
are
fully
 understood
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 7
 What’s
the
Big
Deal?
 •  Ethics:
big
corporate,
profits
ahead
of
needs
 –  Who
chooses
what
might
be
a
“good”
idea?
 •  Roundup‐Ready
Crops
 •  “Terminator”
seeds
 •  Monsanto
pushing
lille
guys
around
(Percy
 Schmeiser)
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 8
 Problem
Here?
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 9
 Gene4c
Diversity
 •  Monocultures:
large
single‐crop
plan4ngs
 •  More
efficient
plan4ng
and
harves4ng
 •  Not
as
ecologically
conducive
(i.e.,
mul4ple
 organisms
like
mul4ple
habitats)
 •  Highly
suscep4ble
to
disease
and
insects
 •  All
our
eggs
in
one
basket
 •  Conserving
na4ve
races
of
crops
is
one
 counter‐strategy,
but
“contamina4on”
an
 issue
 •  Seed
banks
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 10
 Pest
Control
 •  •  •  •  Insec4cides
+
herbicides
+
fungicides
=
pes2cide
 >7000
pes4cides
registered
for
use
in
Canada
 Mul4‐billion
dollar
industry
 Types:

 –  Organochlorines
(DDT,
aldrin,
chlordane):
persistent,
 bioaccumula4ve,
affect
reproduc4on
 –  Organophosphates
(malathion):
not
persistent,
systemic,
not
 very
selec4ve,
toxic
to
humans
 –  Carbamates
(aldicarb):
not
persistent,
not
very
selec4ve,
toxic
to 
 fish
and
birds
 –  Phenoxy
(2,4‐D):
effects
poorly
understood;
causes
cancer
in
lab
 animals
 –  Pyrethroids
(deltamethrin):
more
selec4ve,
not
acutely
toxic
to
 birds
or
mammals,
but
highly
toxic
to
aqua4c
organisms
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 11
 Pes4cide
Resistance
 •  Pes4cide
usefulness
declines
over
4me
as
 pests
evolve
resistance
to
effects
 •  “Evolu4onary
arms
race”
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 12
 Integrated
Pest
Management
 (IPM)
 •  Integra4on
of
numerous
techniques
 (chemicals,
biocontrol,
habitat
altera4on,
 GM,
alterna4ve
4lling)
to
suppress
pests
over
 long‐term
 •  Biocontrol:
control
of
insects
or
weeds
by
 introducing
organisms
that
eat
or
infect
them
 •  Bacillus
thuringiensis:
natural
soil
bacterium
 that
kills
caterpillar,
fly,
and
beetle
larvae
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 13
 Indonesia
and
IPM
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 14
 Intensive
Livestock
Agriculture
 3
big
points:

 1.  The
world
is
ea4ng
WAY
more
meat
and
 seafood
 2.  Raising
livestock
is
energy
intensive
 (vegetarianism)
 3.  To
meet
demand,
opera4ons
have
been
 densified
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 15
 Consump4on
 •  5X
increase
in
meat
produc4on
since
1950
 •  Subject
to
biodiversity
issues
as
well

62
 livestock
breeds
went
ex4nct
between
2000
 and
2006
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 16
 Feedlots/Factory
Farms
 •  High
density
livestock
rearing
(especially
 chicken
and
pork)
 •  Benefit:
reduces
overgrazing
and
soil
 degrada4on
 •  Air
and
water
pollu4on:
a
single
cow
can
 produce
2x105
kg
of
“waste”
per
year;
some
 feedlots
rear
>100,000
calle
in
one
place
 •  An4bio4cs
for
disease
control
 •  “mad
cow”;
“bird
flu”
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 17
 Feedlots/Factory
Farms
 hlp://video.humanesociety.org/video/629262638001/Channels/602022756001/Latest‐ Videos/1044327352001/Cage‐vs‐Cage‐Free/
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 18
 Livestock:
High
Energy
Produc4on
 •  45%
of
global
grain
produc4on
 goes
to
feeding
livestock
 •  Lose
up
to
90%
of
energy
 moving
between
trophic
levels.
 
 •  Some
food
produc4on
is
more
 “efficient”
than
others
 •  One
clear
thing:
the
lower
you
 eat
on
the
food
chain,
the
less
 energy
your
diet
requires
and
 less
land
area
and
natural
 resources
required
to
feed
you
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 19
 Aquaculture
 •  Produc4on
of
“farmed”
fish
has
 increased
~7X
in
20
years
 •  Great
for
food
security,
 preven4ng
overharves4ng
of
 natural
popula4ons,
and
it
is
 actually
quite
efficient
 •  Disadvantages:

 Lecture
8
–
Food
and
Gene4c
Biodiversity
 –  Super‐crowded
condi4onsdisease
 –  Possible
escape
and
compe44on
 with
na4ve
species
 –  GM
fish
also
quite
prevalent,
 leading
to
similar
issues
as
with
 crops
(weaken
na4ve
popula4on
by
 interbreeding,
compe44on)
 20
 Sustainable
Agriculture
 •  Agriculture
that
does
not
deplete
soils
faster
 than
they
form;
preserves
clean
water
and
 gene4c
diversity
 •  Organic
agriculture:
food
growing
that
 excludes
synthe4c
fer4lizers
and
pes4cides
 –  <1%
of
global
farmed
land,
but
increasing
15‐20%
 per
year
 –  More
expensive
and
usually
less
good‐looking,
 but
beler
for
you
and
environment
 –  Can
s4ll
control
pests
via
e.g.
biocontrol
 –  Cuba
example
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 21
 Organic
vs.
Non‐Organic
 Non‐Organic
 Organic
 Chemical
fer4lizers
applied
to
 promote
growth
 Rely
on
natural
fer4lizers
like
 manure
and
compost
 Insec4cides
used
 Use
biocontrol
(birds
and
 insects),
ma4ng
disrup4on,
or
 traps
 Chemical
herbicides
used
 Tilling,
hand
weeding,
and
 mulching
for
weed
control
 Animals
given
an4bio4cs,
 hormones,
and
medica4ons
 Rely
more
on
preventa4ve
 measures
(eg.
clean
housing,
 rota4onal
grazing)
 Source: mayoclinic.com Lecture
8
–
Food
and
Gene4c
Biodiversity
 22
 The
“Least
Organic”
Foods
 •  •  •  •  •  •  •  •  Apples
 Celery
 Strawberries
 Peaches
 Spinach
 Nectarines
 Grapes
 Bell
Peppers
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 •  •  •  •  Potatoes
 Blueberries
 Leluce
 Kale/Collard
Greens
 23
 Biodiversity
 Several
measures:

 1.  Species
diversity
 –  number
and/or
variety
of
 species
 2.  Gene4c
diversity
 –  variety
of
DNA
within
 species
 3.  Ecosystem
diversity
 –  Number
and
variety
of
 ecosystems
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 24
 Species
we
know
about
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 25
 Biodiversity
Spa4ally
Variable
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 26
 Loss
of
Biodiversity
 •  Ex2nc2on:
species
ceases
to
exist

 •  Ex2rpa2on:
loss
of
a
species
from
a
 par4cular
area
 •  Endangered:
in
imminent
danger
of
 becoming
ex4nct
or
ex4rpated
 •  Threatened:
likely
to
become
endangered
in
 the
near
future
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 27
 Ex4nc4on
 •  Natural
process,
but
current
rates
of
 ex4nc4on
are
much
higher
than
“normal”
 Should be 66.5 mya. Dinosaurs!! Lecture
8
–
Food
and
Gene4c
Biodiversity
 28
 Major
Causes
of
Biodiversity
Loss
 1.  2.  3.  4.  5.  Habitat
altera4on
 Invasive
species
 Pollu4on
 Overharves4ng
 Climate
Change
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 29
 Consequences
of
Biodiversity
 Loss
 1.  Loss
of
ecosystem
func4oning
 –  Keystone
species
 –  Ecosystem
engineers
 2.  3.  4.  5.  Food
security
 Loss
of
poten4al
medicines
 Loss
of
eco‐tourism
 Loss
of
nice
places
to
sit
and
think
 Lecture
8
–
Food
and
Gene4c
Biodiversity
 30
 ...
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This note was uploaded on 02/29/2012 for the course ENVIRONMEN eesa01 taught by Professor Mitchel during the Fall '11 term at University of Toronto- Toronto.

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