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AQUATIC ECOLOGY PACKET (INCLUDES VIDEO)-BEGIN READING THROUGH THE LECTURE

TERRESTRIAL ECOLOGYPART DUEX

•Biogeochemical Cycles

•Biomes

•Succession

BIOGEOCHEMICAL CYCLES Fundamental Aspects

BIOGEOCHEMICAL CYCLES

The carbon, phosphorous, nitrogen and sulfur cycles

All illustrate the law of conservation of matter:

The 1st law of thermodynamics- energy Is neither created nor destroyed by it may be converted from one form to another

Fig. 3-7, p. 55

Nitrogen

cycle

Biosphere

Heat in the environment

Heat Heat Heat

Phosphorus

cycle

Carbon

cycle

Oxygen

cycle

Water

cycle

CARBON CYCLE Fundamental Aspects

Carbon Cycle

Is an atmospheric cycle but can be found in all three spheres- air, land and water

Carbon is required for formation of organic compounds in living things.

Carbon is taken out of the air by plants during photosynthesis and is returned to the air by cellular respiration.

Largest reservoir of carbon - sedimentary rocks (limestone)

Second largest reservoir of carbon - ocean (dissolved carbon dioxide), living things in ocean.

BIOGEOCHEMICAL CYCLES

1. C in carbon dioxide in atmosphere and in water is moved to C in glucose by photosynthesis by producers.

2. C in glucose is moved to C in carbon dioxide by cellular respiration.

3. C in glucose is moved to C in organic molecules by synthesis reactions in living things.

4. C in organic molecules is moved to C in carbon dioxide by combustion.

5. C in organic molecules in organisms is moved to C in fossil fuels over millions of years by pressure, heat, and bacterial action.

6. C in limestone (CaCO3) is released slowly to C in carbon dioxide when exposed to oxygen and/or water.

CARBON CYCLE

CARBON CYCLE

Fill in the stages of the Carbon Cycle!

Human Impacts

We alter the carbon cycle by adding excess CO2 to the atmosphere through: Burning fossil fuels.

Clearing vegetation faster than it is replaced.

CARBON CYCLE

THE CARBON CYCLE: PART OF NATURE’S THERMOSTAT

Figure 3-27

C02 is one of our Green House Gases!

As carbon dioxide levels rise, global temperature increases.

SUMMARIZE!

NITROGEN CYCLE Fundamental Aspects

Nitrogen Is an atmospheric cycle. Plants and animals cannot use free nitrogen gas in the

atmosphere. They must have nitrogen in "fixed" form. Nitrogen is required for proteins, nucleic acids in living things.

Nitrogen is often limiting factor in plant growth because ammonia, ammonium ion, nitrate are water-soluble: can be leached from soil.

The main reservoir of nitrogen is in the air78% nitrogen gas

You need phosphorous and nitrogen to build proteins and nucleic acids (part of DNA)

Since more organisms are unable to use nitrogen gas (N2), nitrogen fixing bacteria bind nitrogen with hydrogen to form ammonia (NH3)

BIOGEOCHEMICAL CYCLES

Stages:Nitrogen fixation (atmospheric nitrogen, N2, is converted to a more usable form by bacteria)

Assimilation (absorption of nitrates/ammonia, by plants)

Ammonification (production of ammonia, NH3, by bacteria during organism decay)

Nitrification (production of nitrate from ammonia)

Denitrification (conversion of nitrate to N2)

NITROGEN CYCLE

Label the 5 stages of the Nitrogen Cycle!

Complicated version

Free N2 in atmosphere is "fixed" by nitrogen-fixing bacteria to NH3 (ammonia)

Nitrogen fixing bacteria live in nodules on the roots of leguminous plants (soybeans, peas, clover, and alfalfa.)

Water in the soil reacts with ammonia to form NH4+ (ammonium ion)

Another species of bacteria can perform nitrification once ammonium has formed

Assimilation - absorption of ammonia, ammonium ion, nitrate for use by plants to make nucleic acids, proteins

Animals get fixed nitrogen by eating plants or other animals.

Plants and animals are broken down by still other bacteria that convert nitrogen-containing organic molecules in organisms to an inorganic form of nitrogen (ammonia or ammonium ion) = ammonification

Once this ammonia has formed, still another group of bacteria can perform denitrification

NITROGEN CYCLE

NITROGEN CYCLE: BACTERIA IN ACTION

Figure 3-29

Nitrogen and Human Impact

We alter the nitrogen cycle by:Adding gases that contribute to acid rain.

Adding nitrous oxide to the atmosphere through farming practices which can warm the atmosphere and deplete ozone.

Contaminating ground water from nitrate ions in inorganic fertilizers.

Releasing nitrogen into the troposphere through deforestation.

Planting many legume cropsAccelerates the normal rate of nitrogen fixation

NITROGEN CYCLE

Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined.

Figure 3-30

NITROGEN CYCLE

SUMMARIZE!

PHOSPHORUS CYCLE Fundamental Aspects

Phosphorous-

Phosphorus is required in the form of phosphate ions for nucleic acids, ATP, phospholipids in cell membranes, bones, teeth, shells of animals.

Does not contain a gaseous phase Is a sedimentary cycle - does not include the atmosphere.

Recycled only if the wastes containing it are deposited in the ecosystem from which it came Limiting factor for plants

BIOGEOCHEMICAL CYCLE

The phosphorus cycle is slow and phosphorus is usually found in rock formations and ocean sediments.

Phosphorus is found in fertilizers because most soil is deficient in it and plants need it.

Phosphorus is usually insoluble in water and is not naturally found in most aquatic environments.

PHOSPHORUS CYCLE

Phosphate on land and in ocean sediment released by weathering into water and taken up by plants. Can be limiting factor for plant growth - is present in artificial fertilizer.

Animals get phosphorus by eating plants or other animals.

Decomposition changes organic molecules with phosphorus back into phosphate which dissolves in water which returns the phosphorus to ocean sediment or deposited as rocks.

PHOSPHORUS CYCLE

Figure 3-31

PHOSPHORUS CYCLE

Phosphorous and Human ImpactMining of phosphate for fertilizers and soap causes disruption to ecosystems.

Removal of phosphorus from ecosystems by cutting down of vegetation. Most of phosphorus is taken up as biomass.

Excessive phosphate in runoff from fertilizer, discharge of sewage, farm waste causes growth of algae, etc. (same problem as nitrogen).

PHOSPHORUS CYCLE

SUMMARIZE!

SULFUR CYCLE Fundamental Aspects

Sulfur Cycle

Is an atmospheric cycle.

H2S (hydrogen sulfide) and SO2 (sulfur dioxide) released into atmosphere from natural (volcanoes) and non-natural sources.

BIOGEOCHEMICAL CYCLES

SULFUR CYCLE

Sulfur and the Human Impact

We add sulfur dioxide to the atmosphere by: Burning coal and oil

Refining sulfur containing petroleum.

Converting sulfur-containing metallic ores into free metals such as copper, lead, and zinc releasing sulfur dioxide into the environment.

SULFUR CYCLE

SUMMARIZE!

BIOMES

Defined by temperature and precipitation

As you move from Arctic to equator, generally speaking, there is an increase in mean annual temp and mean annual precipitation

Biomes tend to converge around latitude lines on the globe.

Separated by physical barriersOcean, mountains, etc

BIOMES

Terrestrial Biomes-Desert

Temperate Grassland

Woodland

Chaparral

Tundra

Tropical Forests

Temperate rainforests

Temperate deciduous forests

Coniferous Forests

Taigas/Boreal Forest

You need to study the difference between these biomes

BIOMES

Human Impacts on Terrestrial Biomes

Human activities have damaged or disturbed more than half of the world’s terrestrial ecosystems.

Humans have had a number of specific harmful effects on the world’s deserts, grasslands, forests, and

mountains.

Remember HIPPO? It applies here as well!

BIOMES

Lakes and Ponds

Streams and Rivers

Wetlands

Estuaries

Coastal Oceans

Open Oceans

BIOMES

Aquatic Biomes-

SUMMARIZE!

SUCCESSION

Transition of one biotic community to the next

New environmental conditions allow one group of species in a community to replace other groups.

Ecological succession: the gradual change in species composition of a given area

Primary succession: the gradual establishment of biotic communities in lifeless areas where there is no soil or sediment.

Secondary succession: series of communities develop in places containing soil or sediment.

SUCCESSION

Primary Succession: Starting from Scratch

Primary succession begins with an essentially lifeless area where there is no soil in a terrestrial ecosystem

Figure 7-11

SUCCESSION

Examples:

-Lichen growing on a

bare rock

-Glaciers recede and

expose uninhabited soil

-Abandoned parking lot

-An area after a

volcanic eruption where

lava covered and

hardened over the soil

PRIMARY SUCCESSION

Pioneer species- First organisms to live in a new community

Usually brought in by wind or animals

Examples-

Moss, weeds, lichen, opportunistic species

PRIMARY SUCCESSION

Mosses invade an area and provide a place for soil to accumulate.

Larger plants germinate in the new soil layer resulting in additional soil formation.

Eventually shrubs and trees will invade the area.

PRIMARY SUCCESSION

SUMMARIZE!

Secondary Succession: Starting Over with Some Help

Secondary succession begins in an area where the natural community has been disturbed.

Figure 7-12

SUCCESSION

SECONDARY SUCCESSION

Usually takes place after a land clearance Fire, landslide, forest clearing

Soil is already there

More rapid than primary

SECONDARY SUCCESSION

SECONDARY SUCCESSION

One Year Later…

Thirteen Years Later…

SECONDARY SUCCESSION

Each successive (new) community is more favorable for new species

Changes in stages until a climax community is established The area is dominated by a few, long lived plant species

Nothing can “succeed” the plants in this community unless some sort

of natural disaster/act of mother nature occurs

SECONDARY SUCCESSION

SUMMARIZE!

Aquatic SuccessionWhen a body of water is taken over by vegetation

Water becomes shallow, less water volume and more fertile

SUCCESSION

This used to be a lake!

AQUATIC SUCCESSION

SUMMARIZE!