What is biodiversity and how is it measured?

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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

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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)

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Species diversity has two components

• Species richness how many different species are
  present in a habitat
• Relative abundance total number of individuals
  of each species present

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Species Richness and Abundance of a Swamp Forest
on Marylands Eastern Shore
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• Species diversity has two components
• Species richness how many different species are
  present in a habitat
• Relative abundance total number of individuals
  of each species present
• Which area is more diverse?

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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

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Importance of TaxonomyNaming Species

1. Naming things upon which we depend for food and
   medicine means survival.
2. Important to measuring biodiversity
3. Conservation

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Basics About Taxonomy
Most inclusive category
Least inclusive category
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Linnea borealis Twin Flower
Linnaeus (1707 -1778)
Taxonomy
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Binomial Nomenclature
Felis domesticus L.
Genus
Species epithet
Author
The house cat
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Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Felidae
Genus Felis
Species Felis domesticus
Classification Taxonomy
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Wild Felis sp.
Felis pardalis Ocelot
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Other Genera of the Cat Family
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Family Felidae
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Kingdom Animalia
Phylum Chordata
Class Mammalia
Suborder Aeluroidea
Order Carnivora
Family Felidae
Genus Felis
Species Felis domesticus
Classification Taxonomy
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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
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Aeluroidea
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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
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Domains and Kingdoms
Domains
Eubacteria
Archaea
Eukarya
Kingdoms
Animal
Fungi
Plant
Archaebacteria
Protist
Eubacteria
Common ancestor
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Food Requirements
Kingdom
Eubacteria Archaebacteria
chemosynthesis photosynthesis
Protista Algae Slime molds Protozoa
chemosynthesis photosynthesis Ingest food
Absorb food in solution
Fungi True fungi
Plants Bryophytes Vascular Plants
photosynthesis
Animals Multicellular animals
Ingest food
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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

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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)
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Number of Living Species of All Kinds of
Organisms Currently Known
Insects 54
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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 earths
  surface

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Diversity of North and Central American birds
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Why do we know so little?

• 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
• On-going extinction species loss in tropical
  forest is estimated at 6000/year,

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• Tropical rain forests are more species rich than
  northern regions of the world
• What are some factors that might account for this?

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Some factors that affect the biodiversity of an
area

• Historical Events
• Time
• Habitat conditions
• Habitat structure
• Climate stability
• Competition
• Predators
• Keystone species
• Disturbance

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• 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

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Extent of Glaciation in the Pleistocene
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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

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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.

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3. Habitat Structure The Forest
Communitystratification

• The canopy
• The shrub layer
• The understory
• The herbaceous layer
• most conspicuous in the spring
• The forest floor

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4. Climate Stability

• How do the Tropics differ in climate from
  Temperate regions?

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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

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6. The Nature of Disturbance

1. Damage communities
2. Remove organisms
3. Alter resource availability

Ice Storms
Flooding
Fire
Storms and Hurricanes
Tornados
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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

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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).

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FIRE Yellowstone fires of 1988 Fire has been
used to manage marshes and forests
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Optional ActivityUnit 3 Activity 31Track Your
UnderstandingAnswer Question 2 on pages
464-465worth 5 points
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Species ExtinctionPast and Present

• Extinction is a biological reality
• Extinction and evolution are intricately related
• Five mass extinctions in the earths 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

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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 earths history
• Can scientists accurately measure extinction
  rates?

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Estimates of Extinction Ratesthe 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

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Island BiogeographySpecies richness and island
size
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Conserving the Biodiversity of the Commons

• Conserving the worlds biodiversity is based on
  principles of biology
• Population biology
• Conservation biology

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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

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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
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• 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

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Principles of Conservation Biology

• Characteristics of habitats that favor species
  preservation
• Large rather than small Bigger is better
• Close together rather than far apart
• Whole rather than internally fragmented
• Linked by corridors rather than isolated
• Inaccessible rather than easily accessible to
  people

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• Island Biogeography (studying populations on
  islands) teaches us about conservation on main
  lands
• Why?
• Habitat fragmentation
• Example fragmenting a forest

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• The main land of South America is to the
  Galapagos Islands as
• An intact forest is to the fragmented parcels

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When habitats become islands

• 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

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Habitat Loss and Fragmentation for Real
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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

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Agriculture with Forested Corridors
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Algonquin to Adirondack Wildlife Preservation
Project
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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.

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• 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 1800s early 1900s
• 80 of the land around the Chesapeake was cleared
  of its forests.
• Wetlands were drained for farm land.

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• The pattern of farm fields, forests, and marshes
  surrounding Blackwater Wildlife Refuge
• Dorchester Co. Eastern Shore
• Blackwater Wildlife Refuges Wildlife Drive is
  circled