1 / 51

Ecosystems

Explore the intricate dynamics of ecosystems, from energy flow and chemical cycling to trophic levels and biodiversity. Learn about ecological pyramids, biogeochemical cycles, and the impacts of human activities on the environment.

ebarkman
Download Presentation

Ecosystems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ecosystems Chapters 55 & 56

  2. Ecosystems • All abiotic factors & species

  3. ecosystems ◀ An island ecosystem ▼ A desert springecosystem

  4. Ecosystems • Processes in the ecosystems • 1. Energy • Comes from sun • Photosynthesis(chemical energy) • 2. Biogeochemical cycles(nutrients) • Chemicals that move through ecosystems • Mostly found in nonliving reservoirs

  5. Sun Key Chemical cyclingEnergy flow Lossofheat Primary producers Primaryconsumers Detritus Microorganismsand otherdetritivores Secondary and tertiaryconsumers

  6. Ecosystems • Photosynthesis • Decomposition & respiration return elements to abiotic forms • Elements are recycled • Energy is released as heat • Sun continuously supplies energy • Evaporation & precipitation circulate elements

  7. Trophic levels • Energy flow through the ecosystem • Autotrophs: primary producers • Heterotrophs: consumers • Primary consumers: herbivores • Secondary consumers: carnivores • Decomposers: break down organic matter • Detritivore: live on refuse of ecosystem

  8. Trophic levels • “trophos” means feeder • All levels feed on another • Food chain • Represents these levels • Food web: • More complex relationships between levels

  9. Decomposers ▼ Fungi decomposinga dead tree ▲ Rod-shaped and sphericalbacteria in compost (colorizedSEM)

  10. Food chain

  11. Food chain

  12. Food web

  13. Energy flow • Primary productivity: • Amount of energy produced by photosynthesis (organic matter) in a community • Biomass: • Total mass of organisms in an ecosystem • Rainforests or wet lands have a high productivity

  14. Energy flow • Secondary productivity • Rate of biomass of heterotrophs • Less than primary due to • 1. Not all plants are consumed by herbivores • 2. Some energy of herbivores is passed as waste • 3. Some energy is lost as heat

  15. Energy flow

  16. Energy flow • Gross primary production (GPP) • Amount light energy converted to chemical energy over time • Net primary production (NPP) • GPP less the amount of energy for plant cellular respiration (R) • NPP= GPP-R

  17. Energy flow · Net primary production (kg carbon/m2·yr) 0 1 3 2

  18. Energy flow in food chains • Ecological pyramids • Relationship of energy, biomass or numbers in an ecosystem • The limit is based on amount of sunlight and nutrients available

  19. Ecological pyramids

  20. Ecological pyramids

  21. Ecological pyramids

  22. Ecological pyramids

  23. Water cycle • Oceans cover ¾ of earth’s surface • Sun powers evaporation of water from oceans • 90% of water in atmosphere over land comes from plant transpiration • Most falls over the ocean as rain • 2% is frozen in ice • Water supplies the hydrogen in ATP formation

  24. Water cycle

  25. Carbon cycle • Photosynthesis uses up about 10% of atmospheric CO2 • Respiration replaces CO2 in the air • Most CO2 is in fossil fuels, coals, gas • Use of these is increasing CO2 in the atmosphere

  26. Carbon cycle

  27. Nitrogen cycle • Prokayotes “fix” nitrogen to usable form • Nitrogen is being added to the system by fertilizers

  28. Nitrogen cycle

  29. Phosphorus cycle • Exist in mineral form (not atmosphere) • Need for ATP, phospholipids, DNA, RNA • Fertilizers adding a lot

  30. Phosphorus cycle

  31. Ecosystem stabilization • More diverse species (species richness) • 1. Ecosystem productivity • 2. Spatial heterogencity • More habitat variation (soils, topography) allows more areas for animals to live • 3. Climate • More stable the weather the greater the species

  32. Biodiversity hotspots

  33. Biodiversity

  34. Biodiversity • 1. Genetic diversity • 2. Species diversity • 3. Ecosystem diversity

  35. Threats to Biodiversity • Habitat loss • Introduced species • Overexploitation

  36. Problems • Pollution • Rhine river (Mercury, pesticides 1986) • DDT (chlorinated hydrocarbons) • Absorbed in animal fats • Biological magnification: • Become more concentrated in food chain

  37. DDT

  38. Acid rain • Sulfur dioxide • Forms sulfuric acid when comes with rain • Lowers pH • Kills wildlife

  39. Acid rain

  40. Farming

  41. Ozone layer • Protects against UV • Thinning 1975 • Chloroflurocarbons (CFC’s) • Increased melanoma

  42. Ozone

  43. Ozone

  44. Greenhouse effect • Increased carbon dioxide & other gases • Reflects heat from earth • Keeping it in the atmosphere • Global warming

  45. Greenhouse effect

  46. Effect of warming • Plants/animals further north • Migratory changes • Species have problems adapting • Increasing sea level • Retreating glaciers • More severe weather changes

  47. Logging

  48. Conservation • Conservation Biology: • Attempts to conserve biodiversity • Restoration Ecology: • Return ecosystems to natural state

More Related