Earth's Living Systems: Understanding Ecosystems and Biogeochemical Cycles

1. Chapter 4:Ecosystems: Components, Energy Flow, and Matter Cycling “The Earth’s thin film of living matter is sustained by grand-scale cycles of energy and chemical elements.”G. Evelyn Hutchinson

2. What Is Ecology • The study of how organisms interact with one another and with their nonliving environment. • Connections in nature

3. Important Terminology (Biology Review) • Organism • Any form of life • Cell • Eukaryotic cell • Prokaryotic cell • Species • Groups of organisms • Population • Group of interacting individuals of the same species that occupy a specific area at the same time • Genetic Diversity • Variance in genetic makeup of populations • Habitat • Where a population normally lives

4. Levels Of Organization

5. Earth’s Systems • Atmosphere • Troposphere/Stratosphere • Hydrosphere • Liquid water • Ice, icebergs, frozen soil layers • Water vapor • Lithosphere • Crust and upper mantle • Biosphere • Where living organisms exist

6. Life On Earth • Life depends on three interconnected factors • 1. One-way flow of high-quality energy from the sun • 2. Cycling of Matter • 3. Gravity

7. Interconnected Factors

8. Ecosystem Concepts and Biomes • Terrestrial portion of the biosphere has been classified into biomes. • These biomes are characterized by: • Distinct climate • Long-term patters of weather • Specific landforms

9. Characteristics of Ecosystems • No distinct boundaries nor self-contained • Abiotic Factors • Range of tolerance • Limiting factor • Biotic Factors • Producers – autotrophs • Consumers - heterotrophs • Herbivores Carnivores • Omnivores Scavengers • decomposers

10. Food Chain Food Web Food Webs and Energy Flow

11. Pyramids of Energy Flow

12. Biogeochemical Cycles • Nutrient cycles – the nutrient atoms, ions, and molecules that organisms need to live, grow, and reproduce are continuously cycled from the nonliving environment and then back again.

13. Water Cycle

14. Water Cycle – Human Impacts • Withdrawing large quantities of fresh water from streams, lakes, and underground sources. • Clearing vegetation from land for agriculture, mining, road and building construction, and other activities. • Modifying water quality

15. Carbon Cycle

16. Carbon Cycle – Human Impacts • Clearing trees and other plants that absorb CO2 through photosynthesis • Adding large amounts of CO2 by burning fossil fuels and wood

17. Nitrogen Cycle

18. Nitrogen Cycle – Human Impacts • Adding large amounts of nitric acid into the atmosphere when we burn any fuel. • Adding nitrous oxide to the atmosphere through the action of anaerobic bacteria on livestock wastes and commercial inorganic fertilizers • Removing nitrogen from topsoil

19. Phosphorous Cycle

20. Phosphorous Cycle – Human Impacts • Mining large quantities of phosphate rock for use in commercial inorganic fertilizers and detergents • Reducing the available phosphate in tropical forests by removing trees. • Adding excess phosphate to aquatic ecosystems: • Runoff of animal wastes • Runoff of commercial phosphate • Discharge of municipal sewage

21. Sulfur Cycle

22. Sulfur Cycle – Human Impact • Burning sulfur-containing coal and oil • Refining sulfur-containing petroleum • Using smelting to convert sulfur compounds of metallic minerals

23. Ecosystem Services “All things come from earth, and to earth they all return. Menander (342-290 B.C.)