TERRESTRIAL ECOLOGY PART DUEX. Biogeochemical Cycles Biomes Succession

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1 DO NOW: -GRAB PAPERS FOR TODAY -GET A HIGHLIGHTER -UPDATE HW FOR TONIGHT COMPLETE AQUATIC ECOLOGY PACKET (INCLUDES VIDEO) -BEGIN READING THROUGH THE LECTURE

2 TERRESTRIAL ECOLOGY PART DUEX Biogeochemical Cycles Biomes Succession

3 BIOGEOCHEMICAL CYCLES Fundamental Aspects

4 BIOGEOCHEMICAL CYCLES The carbon, phosphorous, nitrogen and sulfur cycles All illustrate the law of conservation of matter: The 1 st law of thermodynamics- energy Is neither created nor destroyed by it may be converted from one form to another

5 Biosphere Carbon cycle Phosphorus cycle Nitrogen cycle Water cycle Oxygen cycle Heat in the environment Heat Heat Heat Fig. 3-7, p. 55

6 CARBON CYCLE Fundamental Aspects

7 BIOGEOCHEMICAL CYCLES 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.

8 CARBON CYCLE 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 (CaCO 3 ) is released slowly to C in carbon dioxide when exposed to oxygen and/or water.

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10 CARBON CYCLE

11 Fill in the stages of the Carbon Cycle!

12 CARBON CYCLE Human Impacts We alter the carbon cycle by adding excess CO 2 to the atmosphere through: Burning fossil fuels. Clearing vegetation faster than it is replaced.

13 THE CARBON CYCLE: PART OF NATURE S THERMOSTAT C0 2 is one of our Green House Gases! As carbon dioxide levels rise, global temperature increases. Figure 3-27

14 SUMMARIZE!

15 NITROGEN CYCLE Fundamental Aspects

16 BIOGEOCHEMICAL CYCLES 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 air 78% 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 (N 2 ), nitrogen fixing bacteria bind nitrogen with hydrogen to form ammonia (NH 3 )

17 NITROGEN CYCLE 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, NH 3, by bacteria during organism decay) Nitrification (production of nitrate from ammonia) Denitrification (conversion of nitrate to N 2)

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20 Label the 5 stages of the Nitrogen Cycle!

21 NITROGEN CYCLE Complicated version Free N 2 in atmosphere is "fixed" by nitrogen-fixing bacteria to NH 3 (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 NH 4+ (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 nitrogencontaining 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

22 NITROGEN CYCLE: BACTERIA IN ACTION Figure 3-29

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24 NITROGEN CYCLE 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 crops Accelerates the normal rate of nitrogen fixation

25 NITROGEN CYCLE Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined. Figure 3-30

26 SUMMARIZE!

27 PHOSPHORUS CYCLE Fundamental Aspects

28 BIOGEOCHEMICAL CYCLE 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

29 PHOSPHORUS 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.

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31 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.

32 PHOSPHORUS CYCLE Figure 3-31

33 PHOSPHORUS CYCLE Phosphorous and Human Impact Mining 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).

34 SUMMARIZE!

35 SULFUR CYCLE Fundamental Aspects

36 BIOGEOCHEMICAL CYCLES Sulfur Cycle Is an atmospheric cycle. H 2 S (hydrogen sulfide) and SO 2 (sulfur dioxide) released into atmosphere from natural (volcanoes) and non-natural sources.

37 SULFUR CYCLE

38 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.

39 SUMMARIZE!

40 BIOMES

41 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 barriers Ocean, mountains, etc

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43 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

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46 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!

47 BIOMES Aquatic Biomes- Lakes and Ponds Streams and Rivers Wetlands Estuaries Coastal Oceans Open Oceans

48 SUMMARIZE!

49 SUCCESSION

50 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.

51 SUCCESSION Primary Succession: Starting from Scratch Primary succession begins with an essentially lifeless area where there is no soil in a terrestrial ecosystem 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 Figure 7-11

52 PRIMARY SUCCESSION

53 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

54 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.

55 SUMMARIZE!

56 SUCCESSION Secondary Succession: Starting Over with Some Help Secondary succession begins in an area where the natural community has been disturbed. Figure 7-12

57 SECONDARY SUCCESSION

58 SECONDARY SUCCESSION Usually takes place after a land clearance Fire, landslide, forest clearing Soil is already there More rapid than primary

59 SECONDARY SUCCESSION

60 SECONDARY SUCCESSION One Year Later Thirteen Years Later

61 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

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63 SUMMARIZE!

64 SUCCESSION Aquatic Succession When a body of water is taken over by vegetation Water becomes shallow, less water volume and more fertile

65 AQUATIC SUCCESSION This used to be a lake!

66 SUMMARIZE!