Biological diversity (1980)
Biodiversity (1985, 1986)
A Shifted Focus
Nature not self-contained or equilibrial
(various time scales)
Human influence widespread, humans
depend on environment
The extinction crisis, habitat critical,
and the pure effects of diversity
Tropical forest loss
=Biodiversity focus
Conservation responses
• Individual species or groups (Intrinsic rights
and utilitarianism)
• Wild, pristine, human-free places
(Preservation Ethic)
• Wise use, sustained yield, sustainability
(Resource Conservation Ethic)
• Holism of Leopold, people in the equation
(Evolutionary-Ecological Land Ethic)
• And now: biodiversity
Defining Biodiversity
The floor is open
Extremes
• Narrow definition: species richness
The ATBI in Great Smoky
Mountains National Park
www.dlia.org
Caves to treetops
As of 2007, 860 species new to
science
As of 2007
5,000
species new
to the Park
Why is it so hard to answer
the questions:
How many species are there?
When will we be done?
How many species are there?
“It reminds me of the question we used
to get all the time at Mammoth Cave:
How many miles of unexplored cave
are there?”
Phil Francis,
Then Assistant Superintendent
Now Superintendent BLRI
Problem: Scale Dependence
Defining Biodiversity
The variety of life in all its forms, levels
and combinations. Includes ecosystem
diversity, species diversity, and genetic
diversity
IUCN, UNEP and WWF, 1991
Biodiversity is the variability among all
living organisms from all sources, including,
inter alia, terrestrial, marine and other
aquatic ecosystems and ecological
complexes of which they are part; this
includes diversity within species, between
species and of ecosystems.
Convention on Biological Diversity
Biological diversity is the variety and
variability among living organisms and the
ecological complexes in which they
occur…For biological diversity, these items
are organized at many levels, ranging from
complete ecosystems to the chemical
structures that are the molecular basis of
heredity.
US Congress Office of Technology
Assessment 1987
The totality of the inherited
variation of all forms of life
across all levels of variation,
from ecosystem to species to
gene.
Edward O. Wilson
Biodiversity means the whole variety of
life on Earth.
Biodiversity is the grand diversity of life
on Earth and all the interconnections that
support these myriad forms of life.
Biodiversity…is perhaps most commonly
defined as "the full variety of life on
Earth."
Biodiversity is the variation of life
within a given ecosystem, biome, or
the entire Earth.
Biodiversity as found on Earth today
consists of many millions of distinct
biological species, the product of four
billion years of evolution.
The variation of life at all levels of
organization.
Wikipedia
Extremes
• Narrow definition: species richness
• Inclusive definition (Noss):
– Genes, species, ecosystems
– Composition, structure, function/process
4 Biodiversity problems
Definition
Set point
Scale dependence
The equality and inequality of species
2. Set Point
Universality/Historic Constraint
We seek universal principles, some
conservation answers are dependent
on historic condition or precedence
What is the RIGHT level of
biodiversity?
3.Scale dependence
Comparing places:
Coastal Plain Savanna vs. Tropical Rain Forest
3.Scale dependence
Comparing times (detecting change):
Logging, Exotic invasion
4. The equality and inequality
of species
• Human value
• Range/Abundance: Rarity,
Native/Alien
• Phylogeny
• Evolutionary potential
• Ecological role
• Representativeness, Surrogacy
Surrogacy in conservation planning
Data are incomplete:
Can some species be surrogates for biodiversity?
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•
•
•
Flagship
Focal, Indicator
Keystone (driver-passenger species)
Umbrella
World Wildlife Fund
Indicator Species
Keystone Species
Ecosystem Engineer Species
Ecological Role:
Little things, Big things
Wilson 1987
Terborgh 1988
Top Predators
• Ecological meltdown in predator-free
forest fragments
– Terborgh et al. 2001, Science
294:1923-1926.
• Damming led to hilltops becoming
islands; large predators lost,
herbivores increased (ants 100x),
plant cover decreased
Top Predators
• Introduced predators transform
subarctic islands from grassland to
tundra
– Croll et al. 2005, Science 307:19591961.
• Foxes preyed on birds which then
deposited less ocean-derived N,
leading to succession
Top Predators
• Are predators good for your health?
Evaluating evidence for top-down
regulation of zoonotic disease
reservoirs.
– Ostfeld and Holt 2004, Frontiers in
Ecology and the Environment 2:13-20.
• Predators decrease, rodents increase,
transmission of disease to humans
increases
Ecology of Fear, Yellowstone NP
Ecology of Fear, Zion NP
The Rivet Hypothesis
The pure effects of diversity
• What is the relationship of function
to diversity?
– Fisher’s fundamental theorem of natural
selection
– What is the FORM of the function?
• Linear
• Saturating
• Hump-shaped
The Goldilocks problem
• Not too hot, not too cold, but just right
• Species have ranges of tolerance and
optima for given environmental
parameters
• Species tend to have different set points
• A particular change in the environment
or conservation strategy will be good for
some species and bad for others
Biodiversity
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•
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Species richness (taxonomic diversity)
Functional trait diversity
Abundance
Species interactions
Functional traits
• Complimentarity
– Efficiency of use
– Resilience
– Adaptability
• Redundancy
– Insurance (rivets, if rivets are all equal)
– Stability
– Resistance
How would you phrase the question
& test the surrogacy idea?
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•
•
•
Flagship
Focal, Indicator
Keystone (driver-passenger species)
Umbrella
How would you phrase the question
& test the surrogacy idea?
•
•
•
•
Flagship
Focal, Indicator
Keystone (driver-passenger species)
Umbrella
Initial capture of biodiversity
Ongoing process of loss
5 Threats
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Habitat loss and fragmentation
Direct taking of species
Invasive species
Changes in physical and chemical
environment
• Change in natural process: fire, flood,
predation