Ecosystems and Energy Chapter 3

Chapter 3 Primary Themes 1.Distinguish ecological levels 2.Define and explain energy 3.Laws of thermodynamics 4.Reactions for photosynthesis & respiration 5.Explain pyramids & webs in terms of energy, biomass, and relationships 6.Describe life in terms of GDP and NPP

What is Ecology? Ecology – study of the interactions among organisms (biotic) and their abiotic environment.

Level of organization – Ecology in a System: Ecosystem

Spheres of Organization Landscape Ecology – encompasses larger area and several ecosystems Biosphere – the whole earth

Energy Drives Life What types of energy are there?

The Energy of Life Potential vs. Kinetic Energy All energy forms summed into two forms

Types of Energy 1.Chemical - energy stored in bonds 2.Radiant - wave energy: electromagnetic 3.Thermal - energy flow from high heat to low 4.Mechanical - the energy of motion 5.Nuclear - atomic nuclei 6.Electrical - flow of charged particles

The Energy of Life Thermodynamics – the study of energy and its transformations.

The Energy of Life 1 st Law of Thermodynamics – energy can change forms, but is not created or destroyed 2 nd Law of Thermodynamics – “Entropy Rules!” amount of usable energy decreases as energy changes forms 1 st Law deals with quantity of energy 2 nd Law with quality of energy

The Energy of Life Photosynthesis 6 CO H 2 O + radiant energy C 6 H 12 O H 2 O + 6 O 2

The Energy of Life Cellular Respiration C 6 H 12 O O H 2 O 6 CO H 2 O + energy

The Energy of Life Case-in-Point: Life Without the Sun Hydrothermal Vents or Black Smokers Chemosynthesis Tube Worms See You Tube - black smokers

Chemosynthesis An extremophile is any microbe that thrives in extreme conditions of temperature, pressure, salinity, or concentrations of hostile chemicals. Extremophiles commonly belong to the kingdom Archaebacteria. Hydrogen sulfide chemosynthesis 6{CO 2 }+6{H 2 O}+3{H 2 S} → C 6 H 12 O 6 +3{H 2 SO 4 }

The Flow of Energy Through Ecosystems Producers, Consumers, and Decomposers

The Path of Energy Flow Food Chains –

Food Webs –

The Path of Energy Flow Ecological Pyramids Pyramid of Numbers Pyramid of Biomass

The Path of Energy Flow Ecological Pyramids Pyramid of Energy

The Path of Energy Flow Example: Thermodynamics in Action Desert: Primary producers = 100 g / m 2 Temperate forest: Primary producers = 1,500 g / m 2 Food webs very simple, very few tertiary consumers Food webs very complex, more tertiary consumers, some quaternary.

Primary Production Desert Biomass Pyramid Primary producers = 100 g / m 2 Primary consumers = 10 g / m 2 Secondary consumers = 1.0 g / m 2 Tertiary consumers = 0.1 g / m 2 Tertiary consumers must range over large areas to obtain enough energy to subsist. such as kg coyote must range ~12 ha to subsist (30 acres).

Primary Production Temperate Forest Biomass Pyramid Primary producers = 1,500 g / m 2 Primary consumers = 150 g / m 2 Secondary consumers = 15 g / m 2 Tertiary consumers = 1.5 g / m kg coyote only needs ~1 ha to subsist (2.5 acres). Also, possibility of quaternary consumers, like bears. NOTE: just relative examples, not accurate

The Path of Energy Flow Ecosystem Productivity Net Primary Productivity Gross Primary Productivity Plant cellular respiration =

The Path of Energy Flow Ecosystem Productivity