190 likes | 475 Views
Ecosystems: Nature’s Answer to a Perpetual Motion Machine. Could this ecosphere be considered an “ecosystem”?. Characteristics of an Ecosystem. A. It is the basic unit of Ecology B. Includes all the interactions of abiotic and biotic factors
E N D
Ecosystems:Nature’s Answer to a Perpetual Motion Machine Could this ecosphere be considered an “ecosystem”?
Characteristics of an Ecosystem A. It is the basic unit of Ecology B. Includes all the interactions of abiotic and biotic factors C. Must be “self-perpetuating and self- maintaining” D. All have similar structures due to the 4 unbreakable laws of physics
The 2 Energy Laws “Energy can not be created nor destroyed but can be transformed into different forms” • Law of Conservation of Energy Turbine Transformation (Mechanical Energy) Implication: All ecosystems form transformable energy relationships. Steam (Heat Energy) Transformation (Chemical Energy) Fire
Useable Energy Useable chemical energy (organic chemical bonds) passed from one organism to another Food Chain Main Energy Transformers Captures “unusable” energy from “inorganic” sources and transforms energy into useable organic form Usable Energy Processing Methods 1. Photosynthesis 99% Unusable Energy 2. Chemosynthesis 1%
B. 2nd Law of Thermodynamics “In every energy transformation there is a loss of “usable” energy” Implication: 1. As energy is passed through an ecosystem, energy is lost. Energy Lost (heat) Turbine Transformation (Mechanical Energy) 2. Ecosystem must have a constant unlimited energy source to perpetuate Steam (Heat Energy) Transformation Energy Loss (heat) (Chemical Energy) Fire
This Law Explains why: • Measured energy flow through an ecosystem forms an “energy pyramid” Pyramid of Numbers May not be the most accurate… Why? Pyramid of Biomass 2. Food chains tend to be only 4-5 trophic levels
Pyramid of Net Production 10% 10% 10% 6CO2+ 6H2O C6H12O6 + 6O2 • Where does the energy go? • How much energy is transferred from one level to the next? • Important Concepts: • Gross Primary Production: The amount of energy the producers convert to food by photosynthesis. This can be measured in terms of : • a) amount of CO2 taken from the atmosphere • b) amount of C6H12O6 made • c) amount of O2 produced What parts of the world contribute most to primary productivity? Slide 19
Secondary Production Net Primary Production Gross Primary Production 2. Net Primary Production: The total amount of carbon made available to the consumers. Net Primary Production = Gross Primary Production Plant Respiration Where on the earth does most of the Net Primary Production take place? Slide 20 3. Secondary Production: The amount of energy converted to actual biomass by a consumer 4. Limiting Factors: (influence of) Abiotic or biotic conditions that restrict productivity in an ecosystem. Temperature, moisture, soil composition, nitrates and phosphates Slide 17
III. 2 Matter Laws A. All matter is made of atoms Implication: All living things require the same basic atoms NCHOPS > 98% Ca, K, Na, Fe, Cl, < 2% B. Matter can not be created nor destroyed Implication: All living things must “compete” for atoms. The limited amount of atoms must recycle through an ecosystem if the ecosystem is self perpetuating The Major Biogeochemical Cycles: Water, Carbon/Oxygen, Nitrogen, Phosphorus
Biogeochemical Cycles Consumers Producers Biological Interactions Detritivores Nutrients available to producers Abiotic reservoir Geochemical Interactions Geologic processes
The Water Cycle: Required to make “clean” water available for all living things Human Impact 1. Air Pollutants a. Nitrates b. Sulfates Condensation Condensation Evaporation Precipitation Evaporation Precipitation Acid Rain a. Nitric Acid b. Sulfuric Acid Transpiration Percolation Runoff Ground Water Evaporation Condensation Precipitation Transpiration Percolation Ground Water Runoff
The Carbon/Oxygen Cycle: Required for Carbon Building Blocks and Energy O2 in Atmosphere CO2 in Atmosphere CO2 in Atmosphere CO2 + H2O C6H12O6 + O2 Photosynthesis Cellular Respiration Photosynthesis Plant Primary Producers C6H12O6 + O2 CO2 + H2O Secondary Consumers Primary Consumers Combustion Phytoplankton Primary Producers Food Chains Waste / Death Carbon compounds in water Fossil Fuels Detritus Detritivores Decomposition Anaerobic Decomposition 1. Global Warming (Green House Effect) Human Impact 2. Deforestation
The Nitrogen Cycle: Nitrogen Required for Making Proteins (N2) Lightning Nitrogen in atmosphere (N2) Denitrification Animals Plants Food Chains Denitrifying Bacteria Waste Assimilation Death Decomposers (bacteria and fungi) Nitrates (NO3) Nitrogen-Fixing bacteria in root nodules of legumes Nitrification Ammonification Nitrifying Bacteria Ammonium (NH4+) Bacteria soil Nitrogen Fixing Ammonia (NH3) Nitrites (NO2) Ammonifying Bacteria Nitrifying Bacteria Human Impact: 1. Fertilizers Eutrophication: Overgrowth in lakes 2. Sewage
Phosphorus Cycle: Phosphates Required to Make DNA, ATP, Cell Membranes Inorganic Phosphate Organic Phosphate Weathering of phosphate from rocks Plants Geological uplifting Animals Runoff Decomposition Food Chains Algae Plants Dissolved Phosphate Phosphate in soil Waste Death Leaching Assimilation Decomposers Chemical Precipitation Sedimentation = new rocks 1. Fertilizers Human Impact: Eutrophication: Overgrowth in lakes 2. Sewage
Summary of Ecosystems (Red Arrows) As Energy flows through an Ecosystem, energy is: _________________ Lost (Blue arrows) As Matter flows through an Ecosystem, Matter is: _________________ Recycled What are the minimal steps required to have a functional Ecosystem? 1. Producers: For energy transformation 2. Detritivores/Decomposers: For recycling
The 5 Laws of Ecology(according to Dr. Barry Commoner) • Everything is connected to everything else • Everything has to go somewhere • There is no such thing as a “free lunch” • Nature know best • The whole is greater then the sum of its parts • Which laws are being ignored with each of the following issues? • Ozone depletion • Biomagnification of DDT • Cultural Eutrophication • Acid rain • Global warming • Smog in cities • Polluted Drinking water • Human Malnutrition • Over Use of Resources
Effect of Limiting Factors in Aquatic Ecosystems Collection Data Points (in vitro) What is the Limiting Factor in this this Ecosystem? Slide 8
Primary Production of Ecosystems Different Ecosystems have Different Productivity Capabilities #1 #2 #2 #1 1. Which ecosystem is the most productive (g/m /yr) ? 2 2. Which Ecosystem provides the earth with the most primary production? Slide 7
Regional Annual Net Primary Production For the Earth Lower Higher Which Biomes are the Most Productive? Slide 8