Chapter 55/56 Notes

Chapter 55: Ecosystems and Restoration Ecology

Essential KnowledgeEssential Knowledge  2.a.1 – All living systems require constant input of free energy (55.2 & 55.3).  2.d.1 – All biological systems from cells and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy (55.1 – 55.4)  4.a.6 – Interactions among living systems and with their environment result in the movement of matter and energy (55.1, 55.3, 55.4, 55.5).

Ecosystem  All the organisms and abiotic factors in a community.

Ecosystem StudiesEcosystem Studies 1. Energy Flow – the movement of energy through trophic levels. 2. Chemical Cycling – the movement of matter from one part of the ecosystem to another.

Trophic LevelsTrophic Levels  Division of an ecosystem based on the source of nutrition (energy).

Trophic LevelsTrophic Levels 1. Primary Producers 2. Primary Consumers 3. Secondary Consumers 4. Detritivores

Primary ProducersPrimary Producers  Usually plants, capture energy and store it in chemical bonds.  Are the source of the energy available to an ecosystem.

Primary ConsumersPrimary Consumers  Organisms that feed on the producers.  Ex: Herbivores

Secondary ConsumersSecondary Consumers  Organisms that feed on the Primary Consumers.  Ex: Carnivores

Detritivores  Get their energy from the organic waste produced by all levels.  Ex: bacteria and fungi

Food ChainFood Chain  Linear pathway of who eats who in an ecosystem.

Food WebsFood Webs  Network showing all the feeding relationships in an ecosystem.

Primary ProductivityPrimary Productivity  The rate at which light energy is captured by autotrophs or primary producers.

Primary ProductivityPrimary Productivity  NPP = GPP - Rs  NPP = Net Primary Productivity  GPP = Gross Primary Productivity  Rs = Respiration

Available EnergyAvailable Energy  Daily joules of solar radiation.  1% - captured by Ps.  About 170 billion tons of organic matter is created each year.

Primary ProducersPrimary Producers  % of GPP is lost to Rs by the primary producers.  NPP = %  Animals - use only NPP, which limits the food webs.

Limiting FactorsLimiting Factors  Material or nutrient that is not present in sufficient quantity for the primary producers.  Ex: N, P, K, Mg Light, CO 2

Energy TransfersEnergy Transfers  Not 100% efficient.  Averages 10% with each tropic level change  Why?  Second law of thermodynamics.  Waste.  Materials that can’t be digested etc.

Question ?Question ?  Why do most ecosystems have only trophic levels?  There isn’t enough energy passed up through the food web to support more levels.

Implications  There has to be fewer high level consumers in a food web.  The higher level consumers usually need a large geographical area.

Pyramids  Graphical representation of relationships in ecosystems.  Ex: 1. Productivity 2. Biomass 3. Numbers

Question  What would a numbers pyramid look like in an Indiana forest?  Inverted pyramid. Few producers (trees) and many primary consumers.  What would a Biomass pyramid look like in an Indiana forest?  Pyramidal in shape.

Chemical CyclingChemical Cycling  Matter is recycled through ecosystems.  Ex: Biogeochemical Cycles

Matter ReservoirsMatter Reservoirs 1. Organic Materials 2. Inorganic Materials  Available  Unavailable

Representative Biogechemical Cycles  Water  Carbon  Nitrogen  Know one or more of these cycles for various multiple choice questions and possibly a short answer question

Water cycleWater cycle

Carbon cycle

Nitrogen cycle

Energy vs MatterEnergy vs Matter  Energy - flows through ecosystems and is mostly lost as heat.  Matter - cycles in ecosystems.

Chapter 56: Conservation Biology and Global Change

Question ?Question ?  What is Man's influence on Ecosystems ?  Humans have had many negative impacts.

Biological MagnificationBiological Magnification  The concentration of toxins in successive levels of a food web.  Ex: DDT Heavy metals -Hg, Cd, Pb

Causes  Not broken down by digestion/decomposition.  Lipophilic.  Concentrates and effects the upper levels of the food web.

DDT ExampleDDT Example

Greenhouse EffectsGreenhouse Effects  The trapping of heat by the Earth's atmosphere. (CO 2, H 2 O etc.).  Causes:  Warms Earth’s temperatures  Global warming

Carbon Dioxide LevelsCarbon Dioxide Levels  Prior ppm ppm ppm  Point: the levels of CO 2 are rising.  Cause? Probably due to humans.

Human CO 2 Increase CausesHuman CO 2 Increase Causes  Industrialization.  Burning of fossil fuels.  Loss of forests.

Result  Earth will heat up.  Ice caps melt and sea levels will rise.  Climate shifts.  Increased Ps (?)

Exotic SpeciesExotic Species  When transplanted species are too successful and upset the ecosystem in new areas.  Ex: Starlings Fire Ants Carp Invasive species website

Australia  Has had many problems with transplanted species  Ex: Rabbits Cacti Foxes Cane toads Cane Toad National Geographic Video

Summary  Identify the trophic levels of ecosystems.  Recognize the flow of energy through food chains and food webs.  Recognize the calculations used in measuring productivity.  Recognize how productivity and energy transfers can be diagramed in pyramid form.  Recognize that matter cycles in ecosystems.  Identify the concept of Biological Magnification.  Recognize several current environmental concerns.