Ecosystem Structure

1. Ecosystem Structure

2. The Nature of Ecology • The study of the interrelationships between plants and animals and their physical environment • Organisms • Populations • Communities • Ecosystems • Biosphere

3. How do Ecologists learn about natural systems? • Field research • Remote sensing • Geographic information systems (GIS) • Laboratory research • Systems analysis (mathematical, computer models)

4. Matter: anything that has mass and occupies space • Elements • Compounds • Molecules • Mixtures

5. The States of Matter • Solid • Liquid • Gas

6. Energy: the ability to do work • Kinetic energy • Potential energy • Heat

7. The Law of Conservation of Matter • Matter cannot be created nor destroyed • Matter only changes form • There is no “away”

8. Laws Governing Energy Changes First Law of Thermodynamics (Energy) • Energy is neither created nor destroyed • Energy only changes form • You can’t get something for nothing ENERGY IN = ENERGY OUT

9. Laws Governing Energy Changes Second Law of Thermodynamics • In every transformation, some energy is converted to heat (lower quality) • You cannot break even in terms of energy quality

10. Connections: Matter and Energy Laws and Environmental Problems • High-throughput (waste) economy • Matter-recycling economy • Low-throughputeconomy

11. Ecosystem Structure Ecosystems have two general categories of components: Biotic - living organisms Abiotic - nonliving

12. The Biotic Components of Ecosystems • Producers(autotrophs) - Photosynthesis • Consumers(heterotrophs) - Aerobic respiration • Decomposers

13. Consumers Primary, secondary, tertiary, etc. Herbivore - plant eater Carnivore - meat eater Omnivore - mixed plant/animal diet

14. The Abiotic Components of Ecosystems 1) Outside energy source 2) Physical factors that determine weather, climate 3) Chemicals essential for life

15. Outside Energy Source Powers photosynthesis Warms earth Powers water cycle

16. Physical factors that determineweather, climate Heat Wind Precipitation Topography

17. Heat • Location • Reflection • Retention

18. Wind and Precipitation • Uneven heating • Ascending, descending air masses

19. Modifiers • Rotation of the globe • Geologic features

20. Rain Shadows

21. Lake-effect Precipitation

22. Chemicals Essential for Life • Elements and compounds • Recycled between biotic and abiotic parts

23. Organic vs. Inorganic Organic compounds made by living things e.g., proteins, fats, DNA Inorganic compounds produced by biotic or abiotic processes e.g., water, carbon dioxide

24. Limiting Factor Principle Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are optimal for that population. Single factor most over-abundant or deficient in an ecosystem determines presence/absence of specific plants/animals.

25. Ecosystem Concepts and Components • Biomes • Role of climate • Aquatic life zones

26. Biomes - terrestrial ecosystems

27. Tropic of Cancer Equator Tropic of Capricorn Semidesert, arid grassland Arctic tundra (polar grasslands) Desert Boreal forest (taiga), evergreen coniferous forest (e.g., montane coniferous forest) Tropical rain forest, tropical evergreen forest Mountains (complex zonation) Temperate deciduous forest Tropical deciduous forest Ice Temperate grassland Tropical scrub forest Dry woodlands and shrublands (chaparral) Tropical savanna, thorn forest

28. Biomes Determined primarily by precipitation Forests (> 75 cm rain per year) Grasslands (30-75 cm rain per year) Deserts (< 30 cm rain per year)

29. Biomes Determined secondarily by temperature Type of forest, grassland, or desert determined by average annual temperature

31. Aquatic ecosystems Determined by salinity Marine Estuary Freshwater Type determined by: depth, nearness to shore, size, water movement

32. Ecosystem Function • One-way flowof energy • Cycling ofmatter

33. Matter and Energy Flow in Ecosystems • Food chains • Food webs Trophic levels

34. Agave Agave Prickly pear cactus Prickly pear cactus Roadrunner Roadrunner Diamondback rattlesnake Diamondback rattlesnake Darkling beetle Darkling beetle Bacteria Bacteria Kangaroo rat Kangaroo rat Red-tailed hawk Producer to primary consumer Gambel's quail Primary to secondary consumer Yucca Jack rabbit Collared lizard Secondary to higher-level consumer All producers and consumers to decomposers Fungi

35. Ecological Pyramids • Pyramid ofenergy flow • Ecologicalefficiency (10%) • Pyramid ofbiomass • Pyramid ofnumbers

36. Energy Productivity of Ecosystems • Primary productivity • Secondary productivity Energy stored/area/time

37. Matter Cycling in Ecosystems -Biogeochemical or nutrient cycles -Hydrologic cycle (H2O) -Atmospheric or gaseous cycles (C, N) -Sedimentary cycles (P, S)

38. Hydrologic (Water) Cycle Driven by physical forces

39. The Carbon Cycle Driven by biological forces: photosynthesis and respiration

40. The Nitrogen Cycle Root nodules on legumes Cyanobacteria Driven by biological forces: bacteria

41. The Phosphorus Cycle Driven by physical forces

42. Community Change Ecological succession - gradual replacement of one kind of community of organisms by another over time -Initiated by disturbance

43. Ecological Succession: Communities in Transition - Type #1 • Primary succession - begins with barren area, nosoil

44. Ecological Succession: Communities in Transition - Type #1 • Slow soil development by weathering, activities of tolerant species - pioneer species

45. Ecological Succession: Communities in Transition - Type #1 • Gradual changeover to less tolerant species over long periods of time - equilibrium or successional species

46. Primary Succession

47. Ecological Succession: Communities in Transition - Type #2 • Secondary succession - begins with soil already in place

48. Ecological Succession: Communities in Transition - Type #2 • Rapid changeover to less tolerant species over shorter periods of time - rapid because soil already present

49. Secondary Succession

50. Succession and Wildlife