1. Biodiversity Review Fall 2010

2. Definition of Biodiversity Sum total of genetic variability within a given ecosystem or globallySum total of genetic variability within a given ecosystem or globally

3. Why has diversity remained constant The amount of land mass has not significantly changedThe amount of land mass has not significantly changed Therefore the number of ecosystems and consequently niches to be filled has remained relatively constantTherefore the number of ecosystems and consequently niches to be filled has remained relatively constant

4. Causes of decreasing Biodiversity Habitat DestructionHabitat Destruction Habitat Alteration (loss of niches)Habitat Alteration (loss of niches) Habitat Fragmentation (geographic isolation)Habitat Fragmentation (geographic isolation) Genetic dilution (or increase in homozygosity) through the mixing of genetically distinct populationsGenetic dilution (or increase in homozygosity) through the mixing of genetically distinct populations Over exploitation of speciesOver exploitation of species Invasive speciesInvasive species

5. Can we harvest energy from the ocean? Open oceans are relatively unproductive: Open oceans are relatively unproductive: Resources available are not concentrated and therefore are difficult to harvestResources available are not concentrated and therefore are difficult to harvest Light penetration (or lack thereof) limits productivity to only the top layerLight penetration (or lack thereof) limits productivity to only the top layer Lack of nutrient availability limits productivityLack of nutrient availability limits productivity When organisms die, most nutrients are to the deep oceanWhen organisms die, most nutrients are to the deep ocean

6. Endemic Species Definition: Endemics are organisms that are highly specialized for a very specific and localized environment. Endemics typically have low vagility and very narrow rangeDefinition: Endemics are organisms that are highly specialized for a very specific and localized environment. Endemics typically have low vagility and very narrow range Why are endemic species at greater risk for extinction?Why are endemic species at greater risk for extinction? Due to low vagility, and narrow habitat range, any change to habitat will either cause species to be lost or reduce to the point of genetic extinction.Due to low vagility, and narrow habitat range, any change to habitat will either cause species to be lost or reduce to the point of genetic extinction. No other populations are available to draw upon and entire species becomes extinctNo other populations are available to draw upon and entire species becomes extinct

7. Value of Biodiversity True Value of BiodiversityTrue Value of Biodiversity True value of biodiversity is intrinsic. It is the sum total of what it means to each personTrue value of biodiversity is intrinsic. It is the sum total of what it means to each person Problems with assigning valueProblems with assigning value Ecological systems are so complex that true value of one species and the cumulative affect of its and other removal cannot be known for certainEcological systems are so complex that true value of one species and the cumulative affect of its and other removal cannot be known for certain Many of these organisms are not even indentified yet or hold no value to us because of what they areMany of these organisms are not even indentified yet or hold no value to us because of what they are

8. Problems with Conserving Natural Habitats Cost of landCost of land Public lands are forced into varied intensive usesPublic lands are forced into varied intensive uses Political institutions favor development for tax basePolitical institutions favor development for tax base Laws are typically designed to encourage developmentLaws are typically designed to encourage development Lack of public voice / activismLack of public voice / activism Much urban & suburban lands are privately ownedMuch urban & suburban lands are privately owned Greed of societyGreed of society