Ecosystems

EcosystemsHow they work11) Matter, energy and lifeAll chemical reactions, involve rearrangements of atoms to form different kinds of matter.

Molecules and compounds:Molecule: consists of two or more atoms bonded together in a specific wayCompound: consists of two or more different kinds of atoms bonded together2On the chemical level, the cycle of growth, reproduction, death, and decay of organisms is a continuous process of taking atoms from the environment, assembling them into living organisms (growth), disassembling them (decay) and repeating the process.

3Back to the four spheresMatter is constantly being exchanged within and between the four spheres

Key elements include: C, H, O, N, P, and S.

These key elements will form part of organic molecules as proteins, carbohydrates, lipids, and nucleic acids.

4Organic, inorganic, natural or syntheticOrganic are the carbon based molecules that make up the tissues of living organisms

Inorganic are molecules or compounds with neither carbon carbon nor carbon hydrogen bonds.

Natural compounds are those making up living organisms

Synthetic are human made organic compounds.

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In conclusion,

Elements essential to live are present in the atmosphere, hydrosphere or lithosphere as simple molecules.

In living organisms, they are organized in highly complex organic compounds. 6

ENERGY

Does not have mass, nor occupies spaceLight, heat, movement, and electricityAffects matter causing changes in its position or its stateIt is the ability to move matter.7FORMS OF ENERGY

8Laws of thermodinamicsFirst Law of Thermodynamics: "Energy is neither created nor destroyed; it only changes form." It can be related to: "You can't get something for nothing or "There is no such thing as a free lunch".

9Laws of thermodinamicsB. Second Law of Thermodynamics: "Systems will go spontaneously in one direction only toward increasing entropy." Entropy: measure of the degree of disorder in a system.It can be described as:" It takes energy to get energy" or "In any energy conversion, you will end up with less usable energy than you started with" or "If you think things are confused now, just wait" or "Everything moves in the direction of increasing disorder".

10Energy changes in organismsThe same principle of storage and release of energy applies to ecosystems

11Producers and Photosynthesis

12Consumers

13Detritus feeders and decomposersFeed largely on cellulose(high potential energy)Aerobic respirationAnaerobic respiration(Fermentation)142) Energy flow in ecosystemsEnergy Source

The ultimate source of energy on our planet: the sun.

The first basic principle of ecosystem sustainability: "For sustainability, ecosystems use sunlight as their source of energy.

Our planet is sustainable as long as the sun exists.

Ecosystems do not use energy at a faster rate than that available from the sun. (The same cannot be said for humans because of our rate of fossil fuel consumption.)

15Ecosystems and energy productivityEcosystems have different rates of production depending on:

Presence of nutrientsAmount of sun lightClimate

Pg 69

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This figure shows energy flow through Trophic Levels in a Grazing Food Web. Each trophic level is represented as biomass boxes and the pathways taken by the energy flow are indicated with arrows.

173) The cycling of matter in ecosystemsEnergy flows but nutrients cycle. The molecules in an organism will eventually be found in another organism.

Recycling is fundamental for sustainabilityPrevents accumulation of wastesGuarantees that the ecosystem will not run out of essential elements.

18Activity:Describe the cycles ofCarbonPhosphorusNitrogenExplain how they are affected by human activities19Carbon cycle

20Phosphorus cycle

21Nitrogen cycle

224) Implications for human societiesOne of the reasons for studying natural ecosystems is that they are models of sustainability.

As a result we might benefit from understanding what it is that makes them sustainable and, where possible, how to emulate them23

Ecosystems sustainability24The human system

25The value of Ecosystem CapitalEcosystem capital is defined as the goods and services we derive from natural systems.

The value of the worlds ecosystem services and natural capital

17 major ecosystem goods and services (pg 80)

26The value of Ecosystem CapitalThe total value to human welfare of a years services amounts to $38 trillion

The gross world production of the world economy is calculated in $25 trillion.

ecosystem services provide an important portion of the total contribution to human welfare on this planet

27The value of Ecosystem CapitalWhat actions should be taken to preserve the ecosystems capital?28The value of Ecosystem CapitalIf the true value of goods and services provided by ecosystems is considered, then efforts to conserve natural ecosystems should be intensified. Governmental decisions should concentrate on maintaining the ecosystem as a public good.

Our tremendous dependence on natural systems should lead to proper management of those systems.

29http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/natural_systems.htmlhttp://apesnature.homestead.com/chapter3.html

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