Download What is Biodiversity?

One definition
What is Biodiversity?
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Another definition
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Some common elements
"Biological diversity -- or biodiversity - is the sum total of
life's physical expression and genetic potential,
embedded in the array of organisms now alive.
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"The diversity of life in all its forms (plants,
animals, fungi, bacteria, and other
microorganisms) and at all levels of
organization (genes, species, and
ecosystems)." M. L. Hunter
In a practical sense, biodiversity is the living savings
bank for Earth's successful genes, a bank that holds
some 3.5 billion years of life's solutions to the problems
„ Taxonomic
diversity
„ Hierarchically
„ Structure
organized
and function
of surviving and competing on this planet." R. P.
Cincotta and R. Engelman
Dimensions of biodiversity
Genetic
component
Spatial component
Functional
component
Temporal
component
e.g. reproductive
behavior, predation,
parasitism
seasonal
within individuals
communities
within populations
ecosystems
between
populations
landscapes
annual
ecoregions
geological or
evolutionary
between species
daily
Components of Biodiversity:
Genetic Diversity
biogeographic
regions
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Components of Biodiversity:
Genetic Diversity
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Variation within and between individuals and
populations of organisms.
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Resides in variation in the sequence of the four
base-pairs which, as components of nucleic
acids, constitute the genetic code.
Gene diversity
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Each species is the repository of an immense
amount of genetic information.
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The number of genes range from about
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1,000 in bacteria
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10,000 in some fungi
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700,000 or more in many flowering plants and a few
animals
The typical “higher organism” (anything from an
amoeba on up to a human being) contains from 1 to
10 billion nucleotide pairs or genetic letters.
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Interactions
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Variation arises in individuals by gene and
chromosome mutations
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Genes generally function in complexes
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Myriads of unique combinations are what
produces the variation we see
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Prescribe unique traits in anatomy and
behavior and biochemistry
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In turn exquisitely adapt the species to the
ecosystem in which it lives
Caribbean land snails
Why be concerned with intraspecific
genetic diversity?
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Genetic diversity in wild species is key to
preserving their ecological “adaptedness” and
evolutionary potential
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Evolution = Selection | Variation | Heredity
Economic reasons
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An example of intra-specific genetic
variation: Brassica oleracea
Genes from wild relatives
constitute an important source for
improvement of domesticated
species of economic importance to
human society
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Genetic Variability Among Natural
Populations: A local example…
Red-backed salamander and climate
warming
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Striped morphs experience higher mortality in
warmer than colder sites
Distribution in variation among
populations
Fraction among = 0
Fraction among = 1
Consider in context of global climate change
1, 2, 3
1, 1, 1
2, 1, 3
2, 2, 2
3, 2, 1
•e.g., in many Plethodon
50-80% of genetic
variation is unique to
local populations
•For many vertebrates 12% is typical
•This hastens genetic
divergence and perhaps
speciation rates as well
Pronounced
genetic
differentiation
over a few
kilometers in
Desmognathus
imitator
3, 3, 3
Proportion of total genetic variation within
species due to genetic differences between
geographic populations (from Avise 1994)
Group
Population Differences
Mammals
0.242
Birds
0.076
Reptiles
0.258
Amphibians
0.315
Fishes
0.135
Insects
0.097
Crustaceans
0.169
Mollusks
0.263
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Range collapse
California condor
A specific example of what’s at
stake…
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Consider the problem of restoring an
endangered species from a few, remnant
individuals and repopulating its range,
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The northern elephant seal reduced to ~20
individuals in the late 1800's from a historic
range extending from Mexico to Alaska.
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Now rebounded to many thousands
Conclusions about genetic diversity
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Loss of isolated populations along with their
unique component of genetic variation.
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Perhaps the greatest, but most disguised
tragedies of the biodiversity crisis
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Components of Biodiversity:
Species diversity
Components of Biodiversity:
Species diversity
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“Species” is generally regarded as the most
natural scale at which to consider wholeorganism diversity.
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The origination and extinction of species are the
principal agents in governing biological diversity
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Perhaps the most readily measured currency of
biodiversity
Species diversity vs. richness
•Species richness: the number of species present in a given area
RICHNESS vs. EVENNESS
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Ecosystem A
SR = 4
H' = 1.3086
SE = 0.94
Ecosystem B
Ecosystem C
SR = 3
H' = 1.0807
SE = 0.98
SR = 3
H' = 1.0323
SE = 0.94
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• Species diversity: species number weighted by measure of
importance, such as abundance, productivity or size
For example:
Shannon’s diversity index (H) = -∑ρi ln ρi
ρi is the proportion of the total number of specimens of species i expressed
as a proportion of the total number of specimens for all species in the
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Species 1
Species 2
Species 3
Species 4
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ecosystem.
Many people use the term “species diversity” when they mean
species richness
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0
Ecosystem
Adapted from: Hunter, M. Jr. 2002. Fundamentals of Conservation
Biology. Second Edition. Blackwell Science, Massachusetts, U.S.A.
Species diversity is a slippery concept
Species concepts
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Morphological
Biological
Phylogenetic
– Each definition of species produces a different
count of species.
– Therefore, each definition has a different effect
on how we plan conservation.
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An Extraordinary Number
Cryptic Species
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Rana livida complex
taxonomically cryptic
species look very
similar to other species
may be misidentified
(and hence overlooked
as being a different
species).
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So far, about 1.5-1.75
million species have
been identified.
Scientists estimate
that there may be
between 3 and 117
million species.
Most estimates range
between 13-20 million
Spector ©AMNH-CBC
Cone head katydid
Source: Bain ©AMNH-CBC
How many species?
Spatial scales and diversity
Estimated Number of Described Species
Bacteria
9,021 (0.5%)
Archaea
259 (0.01%)
Nematoda Actinopterygii
20,000 (1.1%) 23,712 (1.4%)
Other Vertebrata
27,199 (1.6%)
Other Eucarya
36,702 (2.1%)
Crustacea
38,839 (2.2%)
Other Plantae
49,530 (2.8%)
Arachnida
74,445 (4.3%)
Insecta
827,875 (47.3%)
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Alpha-diversity
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Beta-diversity
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Other invertebrate
Metazoa
82,047 (4.7%)
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Fungi
100,800 (5.8%)
Measured locally, at a
single site
Measures the uniqueness;
the difference between two
sites
Gamma-diversity
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Stramenopiles
105,922 (6.1%)
Measured over a large
scale, same concept as
alpha-diversity
Adapted from: Meffe et al. 2002. Ecosystem management:
adaptive, community-based conservation. Island Press,
Washington, D.C., U.S.A.
Mollusca
117,495 (6.7%)
from Lecointre and Guyader (2001).
Angiospermae
233,885 (13.4%)
Types of Species Diversity:
Alpha Diversity
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The number of species that live in a
homogenous habitat.
To some extent a function of the area of the
habitat
But focus is on the number of species that
are adapted for a particular habitat.
Types of Species Diversity:
Beta Diversity
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Species turnover from one habitat to another
in a heterogeneous region.
Will beta diversity be higher in a region
comprised of:
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(1) savannah and prairie?
(2) wetlands and forest?
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Which is:
Low alpha, high beta?
High alpha, low beta?
Types of Species Diversity:
Gamma Diversity
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The number of species that live in a
heterogeneous region - broad area that has
similar climatic and topographical features
but may have different habitats.
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The actual species may be different in the
habitats, so species turnover is important.
Antarctica
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Consider the flowering plants of
Antarctica!
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a single grass species,
Deschampsia antarctica, and a
small cushion-forming plant or
pearlwort, Colobanthus quintensis.
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Usually co-occur at the same site
Can gamma = alpha such that
beta = 0?
An example?
Arcane academic topics?
Who cares?
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Spatial scale is a critical consideration
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Let’s “maximize” species diversity – who can
argue with it?
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Land managers have for years tried to do so
by creating edge habitats in public forests
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“Edge maximizes diversity”
Outcome of fragmentation
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Clear Lake, Northern California
Since 1800 fish diversity has increased
from 12 to 25 species!
Net increase in alpha diversity:
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Many edge-loving species, such as deer, turkeys,
sparrows, American robins, etc.
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These are somewhere common and secure
Net decrease in gamma diversity:
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All the “area-sensitive” species, e.g., Red-cockaded
Woodpecker
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These may not occur elsewhere
Reality
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12 original native species, 3 of which were endemic
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Dam and introductions knocked out 3 species, including
two of the endemics:
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Clear Lake splittail
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Thicktail chub
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Added 16 new species (carp, cattfish, many sunfishes
and basses, etc.)
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12 + 16 – 3 = 25 (alpha) versus – 2 (gamma/global)
Evolutionary distinctiveness
Other aspects of species
diversity:
Evolutionary distinctiveness
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A straightforward count of the number of species
only provides a partial indication of biological
diversity
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Evolutionary distinctiveness is also important
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The more different a species is from any other
species then the greater its contribution to any
overall measure of global biological diversity.
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Symbiodinium is an extremely diverse genus of dinoflagellates.
Consider the Tuatara
Just two species of tuatara.
•Most common species is
Sphenodon punctatus, the
tuatara which is found on the
Northern Islands.
•Second species is the
Brothers tuatara Sphenodon
guntheri which is unique to
Brothers Island and has an
olive skin with yellow spots.
North Brother
Island
Hey…what’s the big deal?
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~3,000 species of lizards on earth
~6,850 lizards, snakes, and amphisbaneans
Developing this idea further
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Marine habitats frequently have
more different phyla but fewer
species than terrestrial habitats
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This is to say higher taxonomic
diversity but lower species
diversity.
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Thus important to incorporate
quantification of the
evolutionary uniqueness of
species.
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Phylum Ctenophora (comb jellies)
Phyletic and functional diversity
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All except one of the presently described 33 phyla occur in
the ocean while only about half that occur on land
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Consequently, marine organisms display a much larger
“phyletic” diversity than those on land
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Furthermore, 15 phyla are exclusively marine!
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The marine environment has not only a high phyletic diversity
but also a great functional diversity
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See: Norse, E.A. 1993. Global marine biological diversity: A strategy for building conservation into decision
making. Island Press, Washington D.C.383 pp.
Phylum Echiuroidea (Inn keeper worms)
Phylum Nemertea (Ribbon worms)
Phylum Echinodermata, Class: Holothuroid
Implications for conservation
Components of Biodiversity:
Ecosystem Diversity
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Components of Biodiversity:
Ecosystem Diversity
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Ecosystems are characteristic assemblages of species
and their interactions with the environment
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Diffuse to very tight linkages.
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“Ecosystem diversity” difficult concept -- not discrete
entities but grade into one another along a continuum.
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Also explicitly include abiotic components, being partly
determined by soil parent material and climate.
Example of ecosystem types:
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Brackish interdunal swales
Coastal oak-beech forest
Coastal oak-heath forest
Coastal oak-hickory forest
Coastal oak-holly forest
Coastal oak-laurel forest
Maritime beech forest
Maritime holly forest
Red maple-sweetgum swamp
Sea level fen
Endangered Ecosystems of the United States:
A Preliminary Assessment of Loss and Degradation
Reed F. Noss
University of Idaho
Department of Fish and Wildlife
Moscow, Idaho 83844
Edward T. LaRoe III2
National Biological Service
Washington, D.C. 20240
J. Michael Scott
National Biological Service
Idaho Cooperative Fish and Wildlife Research Unit
University of Idaho
Moscow, Idaho 83844
http://biology.usgs.gov/pubs/ecosys.htm
Critically Endangered (>98% decline)
Ecosystems
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Old-growth and other virgin stands in the eastern
deciduous forest biome.
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Spruce-fir (Picea rubens-Abies fraseri) forest in the
southern Appalachians.
Red pine (Pinus resinosa) and white pine (Pinus
strobus) forests (mature and old-growth) in Michigan.
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Longleaf pine (Pinus palustris) forests and savannas in
the southeastern coastal plain.
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Slash pine (Pinus elliottii) rockland habitat in South Florida.
Loblolly pine-shortleaf pine (Pinus taeda-Pinus echinata) hardwood forests in the West Gulf
Coastal Plain.
Arundinaria gigantea canebrakes in the Southeast.
Tallgrass prairie east of the Missouri River and on mesic sites across range.
Bluegrass savanna-woodland and prairies in Kentucky.
Black Belt prairies in Alabama and Mississippi and in the Jackson Prairie in Mississippi.
Ungrazed dry prairie in Florida.
Oak (Quercus spp.) savanna in the Midwest.
Wet and mesic coastal prairies in Louisiana.
Lakeplain wet prairie in Michigan.
Sedge (Carex spp. and others) meadows in Wisconsin.
Hempstead Plains grasslands on Long Island, New York.
Lake sand beaches in Vermont.
Serpentine barrens, maritime heathland, and pitch pine (Pinus rigida)-heath barrens in New York.
Prairies (all types) and oak savannas in the Willamette Valley and in the foothills of the Coast
Range, Oregon.
Palouse prairie (Idaho, Oregon, and Washington and in similar communities in Montana).
Native grasslands (all types) in California.
Alkali sink scrub in southern California.
Coastal strand in southern California.
Ungrazed sagebrush steppe in the Intermountain West.
Basin big sagebrush (Artenisia tridentata) in the Snake River Plain of Idaho.
Atlantic white-cedar (Chamaecyparis thyoides) stands in the Great Dismal Swamp of Virginia and
in North Carolina and possibly across the entire range.
Streams in the Mississippi Alluvial Plain.
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“Ecosystem mapping”
Mount Marcy, New York (< 100 acres of alpine habitat in New
York)
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Despite conceptual difficulties, ecosystem
mapping and classification is now a major
area of activity in conservation biology
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Partly due to efficiency (ecosystem mapping
and management as surrogate for tracking
individual species) and new technologies.
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Provides the “coarse filter” for conservation
An
ecosystem
map of
Tasmania
Latest and greatest on ecosystem
classification
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http://www.natureserve.org/explorer/classeco.htm
Components of Biodiversity: Interspecies interactions
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Components of Biodiversity: Inter-species
interactions
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The number of potential interactions among
species is mind-boggling
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predation,
competition,
parasitism,
mutualism.
Some of these linkages are very tight and are
considered an important component of
biodiversity
Details
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The Weird Sex Life of Figs
Unusual flowering system: flowers are on
the inside of a structure called a syconium
Female fig wasp enters with pollen the
syconium through an opening called the
ostiole.
Female lays eggs in particular flowers with
short styles.
Chemicals released by the female wasp
cause gall formation thus providing the
larvae with an ample food source.
The long-styled flowers do not have wasp
eggs laid in them, and get pollinated by the
fig pollen carried by the female wasp
Last details…
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More details…
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Larva develop into adult wasps barely visible
to the naked eye.
Males hatch early, are wingless
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rove around inside dark chamber,
chomp a hole in the wall of the now mature fig,
fertilize female larvae,
promptly die!
The fertilized female leaves the fig through
this hole, taking pollen with her.
Other examples:
Flowering plants and pollinators
The mature fig remains for you or
some other animal to eat.
The seeds pass through your
digestive system, with their seed
coats weakened by the acid in your
stomach, and fall on the ground,
germinating into another fig tree.
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Ants and aphids
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Termites and endosymbiotic protozoa
Hummingbird flower mites
can go extinct if either the
hummingbirds they use for
transport or flowers on
which the mites depend for
nectar and pollen go
extinct.
In the illustration, the mite
Tropicoseius uniformis,
monophagous on its host
plant Psychotria poepegiana, is
phoretic on the
hummingbird Amazilia
tobaci in Trinidad, West
Indies.
Anemone and clownfish
Cultural Diversity
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Mostly a issue for vertebrate animals:
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Cultural Diversity
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knowledge of migration routes, water holes, food
patches, nesting sites, refugia etc.
based on information passed from older to
younger animals.
Despite our notion of animals as being
evolutionarily hard-wired, much "teaching"
goes on.
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Examples
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Consider what happens to many elephant herds
when the matriarch, who knows the location of water
holes during times of drought, is killed.
Many species reintroduction programs fail because
of lack of regard for cultural transmission, e.g., thickbilled parrot, golden lion tamarin.
Does this information constitute "biodiversity"?
Cultural and Biological
Diversity: Human culture
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Some 200 million indigenous
peoples (4 percent of the world's
population) live in territories that
harbor exceptionally high levels of
biodiversity.
Long occupation of a particular
place means development of
cultural, spiritual, and economic
ties to an area that permitted them
to live in a sustainable fashion
there
End: “What is biodiversity?”
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