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Ecosystems

Ecosystems. Living and Non-living components and structure. Ecology. Biosphere. Ecosystem. The study of how organisms interact with one another and with the nonliving environment. Communities. Populations. Organisms. Ecosystems. Ecosystem

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Ecosystems

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  1. Ecosystems Living and Non-living components and structure

  2. Ecology Biosphere Ecosystem • The study of how organisms interact with one another and with the nonliving environment. Communities Populations Organisms

  3. Ecosystems • Ecosystem • A community of different species interacting with one another and with their nonliving environment • Can be small or large, e.g. a stream or Great Plains • Can be natural or artificial, e.g. crop fields

  4. Components of Ecosystems • Biotic (living components) • Producers = make their own food from compounds obtained from their environment • Photosynthesis = capturing sunlight to make sugars • 6CO2 + 6H2O + sun  C6H12O6 + 6O2 • Consumers = get their energy and nutrients by feeding on other organisms • Aerobic respiration = uses oxygen to convert organic nutrients into carbon dioxide and water • C6H12O6 + 6O2  6CO2 + 6H20 + energy

  5. Types of Consumers • Herbivores • Plant eaters • Primary consumers • Feed directly on producers • Carnivores • Meat eaters • Feed on other consumers • Secondary and tertiary consumers • Omnivores • Eat both plants and animals • Scavenger • Feed on dead organisms • Decomposers • Bacteria and fungi • Complete the final breakdown and recycling of organic materials

  6. Components of Ecosystems (cont.) • Abiotic (nonliving components) • Sunlight • Temperature • Precipitation • wind

  7. Components work together

  8. Energy flow through ecosystems • Food chain • The sequence of organisms, each of which is a source of food for the next • Energy enters most ecosystems as high quality sunlight, which is converted to nutrients by producers. The energy is then passes on to consumers. • As each organism uses the high-quality energy in its food to move, this energy is converted into low-quality heat (2nd law of thermodynamics) • 100% efficiency is impossible as system moves toward entropy

  9. Food Chains and Webs Food Chain Food Web Most consumers feed on more than one type of organism Food web = complex network of many interconnected food chains • All organisms that are the same number of energy transfers away from the original source of energy that enters an ecosystem • Producers = 1st trophic level • Primary consumers = 2nd trophic level • Secondary consumers = 3rd trophic level

  10. Energy Transfer in a Food Web • In a food chain or web, energy is transferred from one trophic level to another, with some usable energy degraded and lost to the environment as heat. • At each successive trophic level, some of the available biomass isn’t digested and expelled as waste • Only a small portion of what is eaten is converted into an organism’s biomass, and the amount of usable energy available to each successive trophic level declines (80-90% is lost)

  11. Mangrove Food Web

  12. Coral Reef

  13. Biodiversity • Totality of genes, species, and ecosystems of a region. • Types of Biodiversity • Genetic Diversity • Species Diversity • Ecological Diversity

  14. What we already know:Diversity Varies by Biome

  15. What we already know, cont.Human impact on ecosystems varies by biome

  16. What we already know, cont.Species diversity is related to ecosystem size Reduction in size of habitat by 90% results in a 50% loss in the number of species Number of West Indian reptiles and amphibians relative to island size

  17. Habitat Fragmentation • Occurs when other land uses break up large contiguous blocks of habitat into smaller patches or when roads, transmission lines, pipelines, or other corridors penetrate blocks of habitat. • These corridors do not necessarily isolate patches of habitat but do compromise the integrity of the habitat interior. • Habitat fragmentation can have negative effects on wildlife and ecosystems through direct habitat loss or indirectly through changes that occur as a result of the adjacent habitat type and the particular land use associated with it.

  18. Habitat Fragmentation and Biodiversity(from 2002 Congressional testimony by EO Wilson)

  19. The Decline in Species Due to Habitat Fragmentation • "And as predicted the numbers of species, in this case mammals, even in our national parks, is declining. The smaller the patch in each island, in turn, the faster the decline. It won’t decline to zero, but it will decline to a new roughly equilibrial state significantly below what it was before those forested areas were turned effectively into islands. • So these are the kinds of facts well documented that should be kept in mind when thinking about the fate of the last remaining undisturbed forests and other habitat as among America’s most precious resources and part of our natural heritage. • I hope Senator Torricelli’s legislation [The Act to Save America's Forests-ed.]will be successful. I think it will be a major step not just for the future environmental security of the United States, but as an example that is badly needed, to be an important step forward for the rest of the world, which is unfortunately copying our tactics with great fidelity.” -E.O Wilson

  20. What we already know, cont.Number of species declining world wide

  21. Biodiversity trends/issues • Identification and protection of diversity hotspots • Changing land acquisition/protection polices to reduce ecosystem fragmentation in existing protected areas • Ecosystem restoration as opposed to species restoration

  22. Hotspots • In a world where conservation budgets are insufficient given the number of species threatened with extinction, identifying conservation priorities is crucial. • British ecologist Norman Myers defined the biodiversity hotspot concept in 1988 to address the dilemma that conservationists face: • What areas are the most immediately important for conserving biodiversity? • The biodiversity hotspots hold especially high numbers of endemic species, yet their combined area of remaining habitat covers only 2.3 percent of the Earth's land surface. • Each hotspot faces extreme threats and has already lost at least 70 percent of its original natural vegetation. • Over 50 percent of the world’s plant species and 42 percent of all terrestrial vertebrate species are endemic to the 34 biodiversity hotspots.

  23. Example #1: • Identifying biodiversity hotspots • IUCN Study of Worldwide Plant Diversity • Number of vascular plant species • Areas of greatest species richness • Areas with data collection and quality problems

  24. Biodiversity Hotspots, cont.Nature Conservancy’s species richness index for land acquisition in the US

  25. Hotspots, cont.Critical Habitat of the Right Whale overlapped with proposed offshore drilling areas (NOAA, 2004)

  26. Reducing Habitat Fragmentation • Can be natural or anthropogenic • Rapid changes in ecosystems prohibits population adaptations.

  27. Reducing Habitat Fragmentation (cont.) • Corridors • Connect habitats – allow movement of species • Issue – will they actually utilize the corridors • Ex) Cabinet Grizzly bears (NW Montana) • Ex) Salmon Ladders • Reduce sprawl • Reduce the footprint of human communities • Issue – social reliance on personal vehicles and “suburban” lifestyle • Ex) urban redevelopment/revitalization

  28. Ecosystem Restoration • Restoration ecology • Field of ecology established in 1980s • Active human involvement – restore ecosystems degraded by human development • Issues – expensive, time consuming, and often fails due to lack of understanding of ecological processes within the system • Ex) Comprehensive Everglades Restoration Plan (CERP)

  29. CERP summary • The Plan was approved in 2000. • includes more than 60 elements • will take more than 30 years to construct • was originally estimated to cost $7.8 billion • The goal of CERP is to capture fresh water that now flows unused to the Atlantic Ocean and Gulf of Mexico. • Water diverted for both habitat restoration and enhancement of water supplies in south Florida (support economy)

  30. Water Diversion

  31. Does it work? • No… • National Research Council Report in 2012 found “that little progress has been made in restoring the core of the remaining Everglades ecosystem; instead, most project construction so far has occurred along its periphery.” • The report noted that to reverse ongoing ecosystem declines, it will be necessary to expedite restoration projects that target the central Everglades, and to improve both the quality and quantity of the water in the ecosystem. • Projected cost now hovers near $14 billion

  32. Changes in flow

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