BIODIVERSITY

I.  Biodiversity
    a.  What does it mean?
    b.  naming things (taxonomy)
II.  Gradients in Biodiversity
    a.  Primary productivity
    b. structure and composition
    c.  Diversity in time


BIODIVERSITY:  The variety of organisms considered at all levels. from genetic variants belonging to the same species through arrays of species, to arrays of genera, families and still higher taxonomic levels.  Includes the variety of ecosystems which comprise both the communities of organisms within particular habitats and the physical conditions under which they live. E. O. Wilson (1992)

Terms to consider:
Species:  a group of organisms where all members do or have the potential to interbreed and produce viable offspring

Population:  a group of individuals of the same species in an area

Community:  all plants and animals inhabiting an area (suggests interactions)

Ecosystem:  grouping of plants, animals and microbes, etc. interacting with each other and their physical environment
"ECO" =  "oikos" (greek for home)
 

Classification Hierarchy
For animals
    KINGDOM
        PHYLUM
            CLASS
                ORDER
                    FAMILY
                        GENUS
                            SPECIES

For Plants
KINGDOM
    DIVISION
        CLASS
            ORDER
                FAMILY
                    GENUS
                        SPECIES


KINGDOM CLASSIFICATION

MONERA: bacteria, nitrogen fixing bacteria

VIRUS: bacteriophages, cold virus

PROTISTA: protozoa, chrysophytes, slime molds

FUNGI: true fungi, mushrooms, yeast, molds,lichen

PLANTAE: green algae, brown algae, red algae, bryophytes, tracheophytes (autotrophs)

ANIMALIA: multi-cellular animals (heterotrophs)


Species are often defined in two ways:

Morphological Species Concept: each species is morphologically distinguishable from its
closest relative.
 

Biological Species Concept: a group of organisms that is reproductively isolated from
another group


BIODIVERSITY THROUGH TIME:

Succession:  Changes in species composition over time (typically short periods i.e. centuries, decades...)
 

Primary and Secondary

Primary Succession:  Succession of plant communities of new land/soil
                (ex. glacial retreat, lava flows, dunes, shrinking lakes)

Secondary Succession:  Previously vegetated land that has been recently disturbed
                (ex. abandoned fields)

Disturbance succession:  Where disturbance creates/initiates the successional process
ex.  fire, wind throw (recovery)

Seres:  Term for series of communities that follow one another/stages of communities in successional sequence include :  early, mid and late seral stages
 


 Characteristics of early and late Successional Stages

                                     EARLY                            LATE

Net Biomass (annual)     high                                   low

Mineral Cycling              open                                closed

Nutrient Exchange           rapid                                slow
Rate

Number of Species           low        -highest-            high

Food Chains                    linear (simple)                   web like (complex)