AP Environmental Science

Chapter 3Terrestrial Ecology

Continued

G. Energy and Matter LawsG. Energy and Matter Laws

1. Thermodynamics:

• 1st law: Energy can not be created or destroyed.

• 2nd law: When energy changes form there is a loss of usable energy.

2. Law of Conservation of Matter:

Matter is neither created nor destroyed but merely changed from one form to another.

H. Ecological Pyramids

1. Pyramid ofenergy flow

1. Pyramid ofenergy flow

Ecologicalefficiency

Ecologicalefficiency

Heat

Heat

Heat

Heat

Heat

1010

100100

1,0001,000

10,00010,000Usable energyUsable energy

Available atAvailable atEach tropic levelEach tropic level(in kilocalories)(in kilocalories)

ProducersProducers(phytoplankton)(phytoplankton)

Primaryconsumers

(zooplankton)

Secondaryconsumers

(perch)

Tertiaryconsumers

(human)

Decomposers

Fig. 4-19, p. 78

Ecological Pyramids

Fig. 4.22, p. 86

Abandoned Field Ocean

Grassland(summer)

Temperate Forest(summer)

p. 92

2. Pyramid ofbiomass

3. Pyramid ofnumbers

Tertiary consumers

Secondary consumers

Primary consumers

Producers

Tertiary consumers

Secondary consumers

Primary consumers

Producers

I 1. Gross primary productivity (GPP)I 1. Gross primary productivity (GPP)

I 2. Net primary productivity (NPP)I 2. Net primary productivity (NPP)

EstuariesEstuaries

Swamps and marshesSwamps and marshes

Tropical rain forestTropical rain forest

Temperate forestTemperate forest

Northern coniferous forest (taiga)Northern coniferous forest (taiga)

SavannaSavanna

Agricultural landAgricultural land

Woodland and shrublandWoodland and shrubland

Temperate grasslandTemperate grassland

Lakes and streamsLakes and streams

Continental shelfContinental shelf

Open oceanOpen ocean

Tundra (arctic and alpine)Tundra (arctic and alpine)

Desert scrubDesert scrub

Extreme desertExtreme desert

800800 1,6001,600 2,4002,400 3,2003,200 4,0004,000 4,8004,800 5,6005,600 6,4006,400 7,2007,200 8,0008,000 8,8008,800 9,6009,600

Average net primary productivity (kcal/mAverage net primary productivity (kcal/m22/yr)/yr)

Fig. 4-22, p. 80

Fig. 4-21, p. 79

Gross Primary Productivity

J. Nutrients: 1. Macronutrients

Chemicals organisms need in large numbers to live, grow, and reproduce.

Ex. carbon, oxygen, hydrogen, nitrogen, calcium, and iron.

J. 2. Micronutrients

These are needed in small or even trace amounts.

Ex. sodium, zinc, copper, chlorine, and iodine.

K. Matter Cycling in Ecosystems (Biogeochemical Cycles)

K. Matter Cycling in Ecosystems (Biogeochemical Cycles)

1. Hydrologic cycle (H2O) 1. Hydrologic cycle (H2O)

Atmospheric cycles

2. Carbon cycle (C)3. Nitrogen cycle (N)

Atmospheric cycles

2. Carbon cycle (C)3. Nitrogen cycle (N)

Sedimentary cycles4. Sulfur cycle (S)5. Phosphorus cycle (P)

Sedimentary cycles4. Sulfur cycle (S)5. Phosphorus cycle (P)

1. Hydrologic (Water) Cycle

Precipitation

Precipitationto ocean

Evaporation

EvaporationFromocean

Surface runoff(rapid)

Ocean storage

Condensation

Transpiration

Rain clouds

Infiltration andPercolation

Transpirationfrom plants

Groundwater movement (slow)

Groundwater movement (slow)

RunoffRunoff

Surface runoff (rapid)Surface runoff (rapid)

Precipitation

Fig. 4-36, p. 81

2. The Carbon Cycle (Terrestrial)

photosynthesisphotosynthesis aerobic aerobic respirationrespirationTerrestrial

rocks

Soil water(dissolved carbon)

Land food websproducers, consumers,

decomposers, detritivores

Atmosphere(mainly carbon dioxide)

Peat,fossil fuels

combustion of wood combustion of wood (for clearing land; or (for clearing land; or

for fuelfor fuel

deforestation

volcanic action

death, burial, compaction over death, burial, compaction over geologic timegeologic timeleaching leaching

runoffrunoff

weatheringweathering

Fig. 4-24, p. 83

The Carbon Cycle (Aquatic)

diffusion between atmosphere and ocean

Carbon dioxidedissolved in ocean water

Marine food websproducers, consumers,

decomposers, detritivores

Marine sediments, includingformations with fossil fuels

combustion of fossil fuels

incorporation into incorporation into sedimentssediments

death, death, sedimentationsedimentation

uplifting over uplifting over geologic timegeologic time

sedimentationsedimentation

photosynthesisphotosynthesis aerobic aerobic respirationrespiration

Fig. 4-24, p. 82

3. Nitrogen CycleN2, is 78% of troposphere (lower atmosphere)

Inert (chemically unreactive nitrogen), can’t be absorbed and used by multi-cellular plants & animals

Must be “fixed” or combined with H or O for plants to use.Lightning – N2 + O2 2NO

Soil bacteria fix nitrogen – N2 + 3H2 2 NH3 (ammonia) Cyanobacteria – in soil and waterRhizobium bacteria live in nodules

on roots of leguminous plantsFactories create fertilizer

nitrate

ammonium

nitrite

4. Phosphorus cycle

Phosphorus Cycle

5. Sulfur Cycle A sedimentary cycle Most stored in rocks and sediments Originates from volcanoes and from

anaerobic decomposition of organic matter in bogs, swamps, and tidal flats

Marine algae can produce DMS (dimethyl sulfide) which act as condensation nuclei, so affect cloud cover and climate

Acid rain contains sulfate salts or sulfuric acid

L. Ecological research1. Field research – observations or

manipulative experiments Relatively new technology: Remote sensing – from aircraft and satellites GIS – Geographic Information Systems

Combine layers of data to produce computerized maps of 1) forest cover, 2) water resources, 3) air pollution emissions, 4) changes in global temperature

2. Lab research Study model systems in controlled

environment – test tubes, cultures, aquaria, greenhouses, etc.

M. Systems Analysis (modeling)

Mathematical and other models that simulate ecosystems

Helps to understand large and complex systems

5 stages (fig. 4-32 on p. 102) Uses

Project possible changes in environ. conditions Anticipate environmental surprises Analyze effect of various alternative solutions

N. Ecosystem Services

We depend on ecosystem services for food, water, air, and other things

a. Fisheriesb. Fresh Waterc. Fertility of soilsd. Fodder for livestocke. Forest products (fruit, coffee, honey, wood for

building, etc.)

Source: Nature Conservation, Summer 2006, p. 29

O. Ecosystem Sustainability

Ecosystems are sustainable because they Recycle chemical nutrients Use renewable solar energy