Ecology

lameubiquityMechanics

Feb 21, 2014 (3 years and 7 months ago)

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Ecology

Individuals

Populations

Communities

Ecosystems

Global systems

Competition, Predation, Mutualism

Interactions with the “environment”

What happens here?

Fig. 49.2, p. 876

energy
input from
sun

nutrient

cycling

PHOTOAUTOTROPHS

(plants, other producers)

HETEROTROPHS

(consumers, decomposers)

energy output (mainly heat)

Fig. 49.4, p. 877

5th

4th

3d

2nd

1st



Fourth
-
level consumers
(heterotrophs):

Top carnivores, parasites,
detritivores, decomposers

Third
-
level consumers
(heterotrophs):

Carnivores, parasites, detritivores,
decomposers

Second
-
level consumers
(heterotrophs):

Carnivores, parasites, detritivores,
decomposers

First
-
level consumers
(heterotrophs):

Herbivores, parasites, detritivores,
decomposers

Primary producers
(autotrophs):

Photoautotrophs, chemoautotrophs



Trophic levels

Fig. 49.6, p. 878

MARSH HAWK

CROW

UPLAND
SANDPIPER

GARTER SNAKE

FROG

SPIDER

WEASEL

BADGER

COYOTE

GROUND SQUIRREL

POCKET
GOPHER

PRAIRIE VOLE

CLAY
-
COLORED
SPARROW

EARTHWORMS, INSECTS (E.G.,
GRASSHOPPPERS,
CUTWORMS)

FIRST TROPHIC
LEVEL

Primary
producers

SECOND
TROPHIC
LEVEL
Primary
consumers
(e.g.,
herbivores)

HIGH?ER
TROPHIC
LEVELS
Complex array
of carnivores,
omnivores and
other
consumers.
Many feed at
more than one
trophic level
continually,
seasonally, or
when an
oppportunity
presents itself

Food webs can be complex in reality

Fig. 49.7, p. 879

Producers
(photosynthesizers)

Producers
(photosynthesizers)

ENERGY
TRANSFERS:

ENERGY
TRANSFERS:

energy lost at each
conversion step from one
trophic level to the next

energy lost at each
conversion step from one
trophic level to the next

ENERGY
INPUT:

ENERGY
INPUT:

herbivores

carnivores

decomposers

decomposers

detritivores

energy in
organic
wastes,
remains

energy in
organic
wastes,
remains

ENERGY
OUTPUT

ENERGY
OUTPUT

energy
losses as
metabolic
heat and
as net
export from
ecosystem

energy
losses as
metabolic
heat and
as net
export from
ecosystem

energy
inputs,
outputs
also occur
between
the two
food webs

Grazing food web

Detrital food web

Fig. 49.11, p. 882

5,060

decomposers/detritivores

21

383

3,368

20,810

top carnivores

carnivores

herbivores

producers

Kilocalories/m2/year

An aquatic system in Florida

Fig. 49.12, p. 882

ENERGY
INPUT:

17,000,000

kilocalories

ENERGY
TRANSFERS:

incoming solar energy
not harnessed:

producers

herbivores

carnivores

top carnivores

decomposers,
detritivores

1,679,190

(98.8%)

20,810

(1.2%)

transferred to the
next trophic level:

Energy still in
organic wastes
and remains

Energy losses as
metabolic heat and
as net export from
the ecosystem:

ENERGY OUPUT:


TOTAL ANNUAL ENERGY FLOW:

4,245

3,368

13,197

383

21

720

272

16

5

5,060

2,265

90

20,810 + 1,679,190


1,700,000

(100%)

Gross primary production

Net primary production

vs.

why is NPP important?

Fig. 49.13, p. 884

geochemical cycle

Main nutrient reservoirs
in the environment

fraction of
nutrient
available to
ecosystem

primary
producers

herbivores,
carnivores,
parasites

detritivores,
decomposers

Flow of matter


Biogeochemical cycles

geological or atmospheric reservoir

biological

systems

WATER

CARBON

NITROGEN

PHOSPHORUS

ATMOSPERE

OCEAN

LAND

evaporation
from ocean

425,000

precipitation
into ocean
385,000

evaporation from
land plants
(evapotranspiration)
71,000

precipitation
onto land
111,000

wind driven water vapor

40,000

surface and
groudwater flow
40,000

Main
Reservoirs

Volume (10
3

cubic kiometers)

1,370,000
29,000

4,000

230

67

14

Oceans

Polar ice, glaciers

Groundwater

Lakes, rivers

Soil moisture

Atmosphere (water vapor)

Fig. 49.15, p. 884

WATER

1.1 million people

without clean water

Fig. 49.17, p. 886
-
87

photosynthesis

aerobic
respiration

TERRESTRIAL
ROCKS

SOIL WATER

(dissolved carbon)

LAND FOOD WEBS

producers, consumers,
decomposers, detritivores

ATMOSPHERE

(mainly carbon dioxide)

PEAT,

FOSSIL FUELS

combustion of
wood (for clearing
land; or for fuel

sedimentation

volcanic action

death, burial, compaction over
geologic time

leaching
runoff

weathering

Carbon

Fig. 49.17, p. 886
-
87

diffusion between
atmosphere and ocean

BICARBONATE
AND CABONATE
DISSOLVED IN
OCEAN WATER

MARINE FOOD WEBS

producers, consumers,
decomposers, detritivores

MARINE SEDIMENTS, INCLUDING
FORMATIONS WITH FOSSIL FUELS

combustion of fossil fuels

incorporation
into sediments

death,
sedimentation

uplifting over
geologic time

sedimentation

photosynthesis

aerobic
respiration

Fig. 49.19, p. 888

Greenhouse effect

Global Change



The observations of temperature (IPCC report)




global average surface temperature has increased over the
20th century by 0.6
°
C



90
-
99% confident that 1990’s warmest decade and 1998
warmest year since 1861



66
-
90% confident that 1990’s warmest decade and 1998
warmest year in past 1000 years.

Is this really due to human activities?

Models indicate natural+human activities provide best fit

recent warming appears to be mainly human influence


Fig. 49.22, p. 890

NO
3
-


IN SOIL

NITROGEN
FIXATION

by industry for
agriculture

FERTILIZERS

FOOD WEBS
ON LAND

NH
3
-
,

NH
4
+

IN SOIL

1. NITRIFICATION

bacteria convert NH
4
+
to

nitrate (NO
2
-
)

loss by
leaching

uptake by
autotrophs

excretion, death,
decomposition

uptake by
autotrophs

NITROGEN FIXATION

bacteria convert to ammonia
(NH
3
+
) ; this dissolves to
form ammonium (NH
4
+
)

loss by
leaching

AMMONIFICATION

bacteria, fungi convert the
residues to NH
3

; this
dissolves to form NH
4
+

2. NITRIFICATION

bacteria convert NO
2
-

to

nitrate (NO
3
-
)

DENTRIFICATION

by bacteria

NITRO?GENOUS WASTES,
REMAINS IN SOIL

GASEOUS N?ITROGEN
(N
2
) IN ATMOSPHERE

NO
2
-


IN SOIL

Nitrogen

Fig. 49.24, p. 892

GUANO

FERTILIZER

ROCKS

LAND
FOOD
WEBS

DISSOLVED
IN OCEAN
WATER

MARINE
FOOD
WEBS

MARINE SEDIMENTS

excretion

weathering

mining

agriculture

uptake by
autotrophs

death,
decomposition

sedimentation

setting out

leaching, runoff

weathering

uplifting over
geolgic time

DISSOLVED IN
SOILWATER,
LAKES, RIVERS

uptake by
autotrophs

death,
decomposition

Phosphorus

Fig. 49.26, p. 894

Energy is transferred from
one organism to another. In
time, all of the energy flows
back to the environment.

Producers trap, convert, and
use or store some energy
from the sun.

NUTRIENT
CYCLING

HETEROTROPHS

(consumers, decomposers,
detritivores)

AUTOTROPHS


(plants, other primary producers)