Biodiversity 12


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  • Figure 55.4 Species density of North and Central American birds. Biogeographers often plot latitudinal trends in numbers of species on maps that illustrate how many species occupy different geographic areas. In this species-density map for breeding species of North and Central American birds, we can see that fewer than 100 species are found in arctic areas, whereas more than 600 species occupy some tropical regions.
  • Grasslands and chapparals are dependant on regular burning By mimicking natural disturbance when necessary, for example using prescribed fire in the sandplains.
  • Figure 53.22 Species richness and island size . This species-area graph illustrates that the number of amphibian and reptile species found on West Indian islands is closely related to island size. Large islands harbor more species because greater habitat diversity allows greater resource partitioning among the resident species, reducing the likelihood of competitive exclusion.
  • …We’d like to see the lowlands look more like this, with vegetated riparian areas, upland corridors, and large areas of restored forest.
  • Biodiversity 12

    1. 1. What is biodiversity and how is it measured? • What is Biodiversity? – The variation that exists in the natural world at all levels of biological organization – All organisms in a defined area, all of their variations and all of their interactions with each other and with the physical environment
    2. 2. Levels of Biodiversity 1. Genetic diversity: the gene pool within a population 2. Species diversity: the number and types of species in an area 3. Higher taxonomic diversity 4. Community Diversity 5. Ecosystem diversity (Habitat diversity)
    3. 3. Species diversity has two components: 1. Species richness: how many different species are present in a habitat 2. Relative abundance: total number of individuals of each species present
    4. 4. Species Richness and Abundance of a Swamp Forest on Maryland’s Eastern Shore 4% 6% 8% 14% 17% 18% 33% 7. American Beech 6. Loblolly Pine 5. American Holly 4. Oaks 3. Sweet Gum 2. Black Gum 1. Red Maple 2003
    5. 5. Species diversity has two components: 1. Species richness: how many different species are present in a habitat 2. Relative abundance: total number of individuals of each species present 3. Which area is more diverse?
    6. 6. Defining Biodiversity: • Old growth forest in the Shenandoah Mountains of Virginia – 50,000 trees represented by 10 species. • Managed forest, recently clear cut – 45,000 trees are maple and birch – Only 1/10th of the forest is represented by the remaining 8 species
    7. 7. Importance of Taxonomy Naming Species 1. Naming things upon which we depend for food and medicine means survival. 2. Important to measuring biodiversity 3. Conservation
    8. 8. Basics About Taxonomy Kingdom Phylum or Division Class Order Family Genus Species Most inclusive category Least inclusive category
    9. 9. Linnaeus (1707 -1778) Taxonomy Linnea borealis Twin Flower
    10. 10. Binomial Nomenclature Felis domesticus L. Genus Species epithet Author The house cat
    11. 11. Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Genus: Felis Species: Felis domesticus Classification & Taxonomy
    12. 12. “Wild” Felis sp. Felis pardalis Ocelot
    13. 13. Bobcat Lynx rufus Panthera tigris Panthera leo Puma concolor Other Genera of the Cat Family
    14. 14. Family: Felidae
    15. 15. Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Genus: Felis Species: Felis domesticus Classification & Taxonomy Suborder: Aeluroidea
    16. 16. Order: Carnivora Suborder: Arctoidea Pinnipedia Otariidae -- sea lions, eared seals, fur seals Odobenidae -- walrus Phocidae -- true (earless) seals, elephant seals Canidae -- dogs, wolves, foxes, coyotes, dingos Ursidae -- bears, panda Procyonidae -- raccoons, kinkajous, ringtails, coatis Mustelidae -- weasels, ferrets, skunks, badgers, otters, sea otter Suborder: Aeluroidea Viverridae -- mongooses, meercats, civets, linsangs Hyaenidae -- hyenas, aardwolf Felidae -- cats, lions, tigers, leopards, cheetah FYI
    17. 17. Aeluroidea
    18. 18. Kingdom Animalia Animalia Phylum Arthropoda Chordata (Vertebrates) Class Malacostraca Mammals Order Decapoda Primates Family PORTUNIDAE swimming crabs Hominids Genus Callinectes Homo Species Callinectes sapidus The Blue Crab Homo sapiens
    19. 19. Eubacteria Archaebacteria Animal Fungi Plant Protist Common ancestor Domains: Kingdoms: Eubacteria Archaea Eukarya Domains and Kingdoms
    20. 20. Eubacteria & Archaebacteria Protista Algae Slime molds Protozoa Fungi True fungi Plants Bryophytes Vascular Plants Animals Multicellular animals Absorb food in solution photosynthesis Ingest food Food Requirements chemosynthesis photosynthesis chemosynthesis photosynthesis Ingest food Kingdom
    21. 21. What you need to know about Classification • The order of classification • Binomial nomenclature (genus, species) • The three Domains • The five Kingdoms • The ecological role of each kingdom • The scientific name of the Blue Crab
    22. 22. Rich in Species, Poor in Knowledge E.O. Wilson estimated 1.75 million species are living on the planet. Scientists generally disagree with the exact number but, agree with Wilson that 1.4 M represents probably a mere 1/10th of the total diversity. Why do we know so little? Other estimates: 4-112 million (7 million)
    23. 23. Number of Living Species of All Kinds of Organisms Currently Known Insects 54% Other Animals 20% Bacteria 4% Fungi 5% Algae 2% Plants 18% Protozoa 2%
    24. 24. What do we know? • Estimates of the # of species • More species are located in the tropical regions of the world – 2/3rd – 3/4th of all species live in tropical rain forests which cover only 7% of the earth’s surface
    25. 25. Diversity of North and Central American birds
    26. 26. Why do we know so little? 1. Not all species have been discovered – #’s are biased toward animal species – Know more about species in developed Nations – Not all species are named as a result of unclear species concepts in taxonomy 2. On-going extinction: species loss in tropical forest is estimated at 6000/year,
    27. 27. • Tropical rain forests are more species rich than northern regions of the world • What are some factors that might account for this?
    28. 28. Some factors that affect the biodiversity of an area 1. Historical Events – Time 2. Habitat conditions 3. Habitat structure 4. Climate stability 5. Competition – Predators – Keystone species 6. Disturbance
    29. 29. 1. Historical Events • Each part of the world has a unique history • Effect of the recent Ice Age in the northern hemisphere – Ireland has no snakes • Time: Older Areas have more species than younger areas
    30. 30. Extent of Glaciation in the Pleistocene
    31. 31. 2. Habitat Conditions • Areas with extreme climate or conditions harbor fewer species • Soldiers Delight Natural Environment Area (NEA) is comprised of 1,900 acres of serpentine barren. The area has over 39 rare, threatened, or endangered plant species as well as rare insects, rocks and minerals. • Delaware River and Pollution
    32. 32. 3. Habitat Structure • Terrain that is simple, uniform, and without much physical variation tends to have fewer species than a complicated terrain with wet and dry spots • Ecologists call these microhabitats • A piece of property with a patch of forest, a small wetland, and a field with harbor a greater diversity than the same sized property that is covered with only forest.
    33. 33. 3. Habitat Structure: The Forest Community stratification • The canopy • The shrub layer • The understory • The herbaceous layer – most conspicuous in the spring • The forest floor
    34. 34. 4. Climate Stability • How do the Tropics differ in climate from Temperate regions?
    35. 35. 5. Competition Among Species • Predators can enhance an area by reducing the population size of prey species • Other species have a chance to get established • Keystone Species have a large effect on the other species of a community – Oysters of the Chesapeake Bay – Vital as water filters, provide habitat, income for watermen
    36. 36. 6. The Nature of Disturbance 1. Damage communities 2. Remove organisms 3. Alter resource availability Fire Flooding Storms and Hurricanes Tornados Ice Storms
    37. 37. 6. Disturbance 1. Create opportunities for the colonization of new species 2. Disturbance is a natural part of the life of a community: most communities are always in recovery from disturbance 3. Humans as agents of disturbance
    38. 38. Hurricane Katrina • Cypress trees play a crucial role in the swamp forests that cover hundreds of thousands of acres of coastal Louisiana. These swamps prevent floods by collecting storm waters and clean water by filtering out pollution. They also provide habitat for a wide variety of animals, such as migratory songbirds (the ivory-billed woodpecker, until recently believed extinct, once thrived in the swamps).
    39. 39. FIRE Yellowstone fires of 1988 Fire has been used to manage marshes and forests
    40. 40. Optional Activity Unit 3: Activity 31 Track Your Understanding Answer Question #2 on pages 464-465 worth 5 points
    41. 41. Species Extinction: Past and Present • Extinction is a biological reality • Extinction and evolution are intricately related • Five mass extinctions in the earth’s history – 99% of species that have ever existed are now extinct • Each mass extinction is followed by a rise in biodiversity of a new set of species
    42. 42. Humans Agents of Extinction • Humans have played a role in the extinction of species for thousands of years • Some say we are facilitating the 6th mass extinction in the earth’s history • Can scientists accurately measure extinction rates?
    43. 43. Estimates of Extinction Rates “the logic of loss” • Estimating rates is difficult at best • Most accurate estimates are for birds and mammals • Species-area relationships from Island Biogeography – # species is related to size of habitat – Estimate habitat loss – 90% habitat loss: 50% species loss
    44. 44. Island Biogeography: Species richness and island size
    45. 45. Conserving the Biodiversity of the Commons • Conserving the world’s biodiversity is based on principles of biology – Population biology – Conservation biology
    46. 46. Principles of Population Biology 1. Small populations are more likely to become extinct than large populations 2. To understand a population it is important to consider factors such as its age structure and sex ratio 3. Populations must be monitored to determine the effects of a conservation plan
    47. 47. Principles of Conservation Biology 1. A species that is broadly distributed across its range is less likely to become extinct than a species that is restricted to a small part of its range The range of the Eastern Fox Squirrel
    48. 48. • The Delmarva Fox Squirrel • Original range included the entire Delmarva peninsula into southeastern PA. • Remnant populations exist at Blackwater, Eastern Neck NWR (Kent Co.), and Assateague Island
    49. 49. Principles of Conservation Biology 2. Characteristics of habitats that favor species preservation: a. Large rather than small; Bigger is better b. Close together rather than far apart c. Whole rather than internally fragmented d. Linked by corridors rather than isolated e. Inaccessible rather than easily accessible to people
    50. 50. • Island Biogeography (studying populations on islands) teaches us about conservation on main lands • Why? • Habitat fragmentation • Example fragmenting a forest
    51. 51. • The main land of South America is to the Galapagos Islands as • An intact forest is to the fragmented parcels
    52. 52. Dooms species by confining them to small, island-like parcels of habitat surrounded by an ocean of human impact. This often leads to: – Inbreeding within small populations – Roads, fences, houses, clear-cuts create barriers to dispersal and reproduction – More susceptible to environmental fluctuations and catastrophes When habitats become islands
    53. 53. Habitat Loss and Fragmentation for Real
    54. 54. Corridors are Important for Connecting “Islands” • Corridors function as pipelines that permit wildlife to move between habitats • Promote biodiversity • But can also transmit disease, fire, predators, and pests • The effectiveness of habitat corridors depends on the situation
    55. 55. Agriculture with Forested Corridors
    56. 56. Algonquin to Adirondack Wildlife Preservation Project
    57. 57. Fragmentation of Habitat in Maryland • Early tobacco farming in the Mid-Atlantic resulted in fragmentation of the land into a fine mosaic of forest patches interspersed with young trees, herbs and shrubs.
    58. 58. • Large scale agriculture stripped extensive areas of the landscape leaving only small patches of forest • The most extensive land clearance in the region occurred in the late 1800’s – early 1900’s • 80% of the land around the Chesapeake was cleared of its forests. • Wetlands were drained for farm land.
    59. 59. • The pattern of farm fields, forests, and marshes surrounding Blackwater Wildlife Refuge • Dorchester Co. Eastern Shore • Blackwater Wildlife Refuge’s Wildlife Drive is circled