Transcript Biodiversity in a Changing World

Biodiversity in a Changing World
Brenda Weiser, Ed. D.
EIH/UHCL
Topics
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What is Biodiversity?
Importance of Biodiversity
Threats to Biodiversity
Invasive Species
Biodiversity is:
the variety of life on Earth at all its levels,
from genes to ecosystems, and the ecological
and evolutionary
processes that sustain it.
Source: ©AMNH-CBC
Dimensions of biodiversity
Genetic
component
within
individuals
Spatial
component
communities
ecosystems
within
populations
between
populations
between
species
landscapes
ecoregions
biogeographic
regions
Functional
component
e.g.
reproductive
behavior,
predation,
parasitism
Temporal
component
daily
seasonal
annual
geological or
evolutionary
Genetic Diversity
The variation in the
nucleotides, genes,
chromosomes, or
whole genomes of
organisms
Source: Human Genome Project, Department of Energy
Population Diversity
• Variation in the quantitative and spatial
characteristics between populations
Importance of population variation
Loss of isolated populations along with their
unique component of genetic variation is
considered by some scientists to be one of the
greatest but most overlooked tragedies of the
biodiversity crisis.
Species diversity vs. richness
• Species richness: the number of species present in a given area
• Species diversity: species number weighted by measure of importance, such as
abundance, productivity or size
Many people use the term “species diversity” when they mean species richness
Community Diversity
• Variation in the groups of populations and
species that share an environment
Ecosystem Diversity
• An ecosystem is a community plus the physical
environment that it occupies at a given time.
Some examples of ecosystems
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coral reefs
tallgrass prairie
coastal wetlands
old-growth forest
tropical rainforest
Mangroves, Belize
Source: Harrison ©AMNH
Source: Brumbaugh ©AMNH-CBC
Inter-species interactions impact
ecosystem diversity
• There are very many potential interactions among species,
such as:
– predation,
– competition,
– parasitism,
– mutualism
• Some of these involve very close ecological and
evolutionary associations between the organisms and are
an important component of community and ecosystem
biodiversity
– consider for example plant pollinators and seed dispersers
Examples of distinct communities and
ecosystems
• Species associated with:
ripening figs in a tropical
forest,
• Species clustered around a
hydrothermal vent on the
ocean floor,
• Species in the spray zone of a
waterfall,
• Species under warm stones in
the alpine zone on a
mountaintop.
Source: ©AMNH
Global Biodiversity Gradient
Biodiversity is not
distributed evenly
across the planet:
Source: Sterling ©AMNH-CBC
Source: Kristan Hutchison,NSF: US Antarctic Program
Species diversity for most taxa is
lowest near the poles, and increases
toward the tropics, reaching a peak in
tropical rain forests (may contain more
than half the species on Earth).
Areas of endemism
• A species is endemic to a certain region if its
distribution is restricted to that region
• Endemism contributes to the uniqueness and special
importance of the biodiversity in particular areas.
• Some areas of the world have particularly high levels
of endemism
The Major Extinction Events
Adapted from Kaufman and Mallory (1986) ‘The Last Extinction’ fig 2.1
Recovery time from previous
extinctions
• Evolution required 10 million years or more
to attain prior levels of species diversity
Sixth mass extinction
Homo sapiens (humans) may be the cause of a sixth
major extinction in history.
Reasons for extinction:
–human population
–pollution
–global climate change
–over hunting
The extinct dodo bird
How a 6th mass extinction might differ
from previous mass extinctions
• causes - apparently human induced
• rate - possibly greater
• possible breadth of taxonomic groups
affected
• it can be stopped or at least slowed!
Why is Biodiversity Important?
Values are Subjective:
Perspectives and Scales
Land developer
Local communities
Government
agency
Oil company
Source: Sterling/Frey © AMNH-CBC
Aquaculture company
Environmental
group
The Value of Biodiversity
• Intrinsic/inherent
value
• Extrinsic/utilitarian/
instrumental value
Source: Burmbaugh © AMNH-CBC
Intrinsic/inherent value
• The value of
something
independent of its
value to anyone or
anything else
• A philosophical
concept
Source: Frey © AMNH-CBC
Categorizing Values
Direct Use
Value(Goods)
Indirect Use
Value
(Services)
Non-Use Values
Food, medicine, Atmospheric and Potential (or
building material, climate
Option) Value
fiber, fuel
regulation,
pollination,
nutrient recycling
Cultural,
Spiritual and
Aesthetic
Future value
either as a good
or service
Existence Value
Value of knowing
something exists
Bequest Value
Value of knowing
that something
will be there for
future
generations
Direct Use Value: Goods
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Food
Building Materials
Fuel
Paper Products
Fiber (clothing,
textiles)
• Industrial products
(waxes, rubber, oils)
• Medicine
Source: © AMNH-CBC
Medicine
• About 80% of the
people in developing
countries use plants as
a primary source of
medicine.
Source: © AMNH-CBC
• 57% of the 150 mostprescribed drugs have
their origins in
biodiversity
Indirect Use Values: Services
• Regulating global processes, such
as atmosphere and climate
• Soil and water conservation
• Nutrient cycling
• Pollination and seed dispersal
• Control of agricultural pests
• Genetic library
• Inspiration and information
• Scientific and educational
• Tourism and recreation
• Cultural, spiritual, and aesthetic
• Community Resilience
• Strategic
Source: © AMNH-CBC
Global Processes:
Atmospheric Regulation
• Photosynthetic
biodiversity created an
oxygenated atmosphere,
and also has the potential
to moderate the rising
amounts of atmospheric
carbon dioxide linked to
global climate change
Source: Frey © AMNH-CBC
Global Processes: Climate Regulation
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Forests and other vegetation modify climate: by affecting sun reflectance,
water vapor release, wind patterns and moisture loss. Forests help maintain a
humid environment, for example, half of all rainfall in Amazon basin is
produced locally from forest-atmosphere cycle
Source: Bain © AMNH-CBC
Soil and Water Conservation
Example: Coastal wetlands and mangroves
• Filters excess nutrients and
traps sediments that would
otherwise impact neighboring
marine and aquatic areas
Other services:
• Minimizes damage from
waves and floods
• Serves as a nursery for
juvenile commercial fish
• Provides habitat for many
birds, fish, and shellfish
Source: Ersts © AMNH-CBC
Nutrient Cycling
• Biodiversity is
critical to
nutrient cycling
and soil renewal
• Decomposers such
as algae, fungi,
and bacteria
Source: Snyder © AMNH-CBC
Pollination and Seed Dispersal
• Many flowering plants
depend on animals for
pollination to produce
food.
• 30% of human crops
depend on free services
of pollinators;
replacement value
estimated billions of
dollars/year in US alone
Source: Spector© AMNH-CBC
Source of Inspiration
or Information
• Biomimicry
• Applied Biology
• Medical Models
• Education and
Scientific Research
Source: Brumbaugh © AMNH-CBC
Spiritual and Cultural Values
• The survival of natural
areas and species are
important to different
cultures around the world.
• Thousands of cultural
groups in the world, each
have distinct traditions and
knowledge for relating to
natural world
Source: Projecto Gato Andino Bolivia, Villalba & Bernal, 1998
Aesthetic Value
Source: Brumbaugh © AMNH-CBC
Ecological Value: Does Diversity
Make Communities More Resilient?
• Resilient ecosystems are characterized by:
– Constancy (Lack of fluctuation)
– Inertia (Resistance to perturbation)
– Renewal (Ability to repair damage)
• Not all species are critical to an ecosystems function;
many fill redundant roles; basis for community resilience
and integrity
• If too many species or keystone species are lost,
eventually it leads to the failure of ecosystem function
Non-Use or Passive Values
• Existence value
• Bequest value
• Potential or Option value
Principal Threats
Direct
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Fragmentation
Invasive Species
Overexploitation
Pollution
Global Climate Change
Underlying
• Overpopulation
• Over-consumption
• Reduced or negative
incentives to conserve
• Lack of enforcement
What are the Threats to
Biodiversity?
Ecosystem Loss and Fragmentation
• Causes
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Agriculture
Human Settlement
Resource Extraction
Industrial
Development
• Result
– Small isolated patches
– Many too small to
support a diverse mix
of species
Source: Sterling©AMNH-CBC
Causes of Fragmentation
Natural
SOURCE: DEPARTMENT OF THE INTERIOR, A. ADAMS
Complex patch
Less distinct edge
Human Caused
SOURCE: FREY©CBC-AMNH
Distinct Edge
Simplified Patch
Invasive Species
• Invasives outcompete,
displace or extirpate local
species
• Exotic species
– Live outside their native
range, not always invasive
• 3 Phases
– Dispersal
– Establishment
– Integration
Dispersal
• Accidental Introduction
– Norway Rat
– Tree Snake
– Diseases - small pox,
measles, rabies, distemper
• Deliberate Introduction
–Wind Break - Casuarinas
–Pest Management - Cane toad
–Pets - Cats
–Food - pigs
Laverty © CBC/AMNH
Consequences of Invasion
• Hybridization with native species
• Disruption of an ecosystems structure and
function
• Displacement of native species as invasives
outcompete them for resources
• Local or even global extinctions
Overexploitation
• Unsustainable levels
of consumption,
harvest or loss
• Direct
– Commercial pressures
Source: FreyAMNH-CBC
• Indirect
– Unintentional
exploitation, e.g.
bycatch of sea turtles
in fishery operations
Source: National Oceanic & Atmospheric
Administration/ Commerce Department
Source: National Oceanic & Atmospheric
Administration / Commerce Department
Pollution
• Many classifications possible
• Wide variety of types and impacts
• Result is a disruptive, persistent and
cumulative impact
Source: National Oceanic & Atmospheric
Administration / Commerce Department
Climate Change
• Global impact
• Increased rate of change
– Appears that the Northern Hemisphere
increase in last 100 years fastest in the last
1,000 years
• Not all areas affected equally
– Alpine and Coastal areas most impacted
Impacts of Climate
Change
• Wide and rapid changes in
distribution of vegetation
types and animal species
• Rise in sea level as glaciers
and snow cover retreat
• Species living close to their
limits will be most
immediately impacted
• Amplify threats to already
endangered ecosystems
Source: National Oceanic and Atmospheric Administration /
Commerce Department
Addressing the Threats
Priority setting at the Species-Level
Atelopus varius
© Robert Puschendorf.
IUCN Red List Program
Structure of the categories
© Fundacion ProAves
www.redlist.org
© Anthony G. Miller.
Dendrosicyos
socotrana
Ognorhynchus icterotis
Global-scale priority setting
Name
Variables used to measure threat
Reference
Global 200
eco-regions
(WWF)
Total Habitat Loss
Degree of Fragmentation
Water quality
Estimates of future threat
Dinerstein et al. 1995
Hotspots
(CI)
Habitat Loss (70% or more of primary vegetation
lost)
Myers et al. 2000,
Myers 2003
Frontier
Forests
(WRI)
Commercial logging
Other biomass harvest
Forest Clearing
Road Construction and Infrastructure
Development
Bryant et al. 1998
Last Wild
Population Density
Places (WCS) Land Transformation
Accessibility
Power Infrastructure
Sanderson et al. 2002
Hot Spots (CI)
Source: http://www.biodiversityhotspots.org/xp/Hotspots/resources/maps.xml (Conservation International)
Regional-scale priority setting
Name
Variables used to measure threat
Reference
TNC’s Eco-regional
planning approach
Severity, Scope, Contribution,
Irreversibility
Groves et al. 2002
WWF’s Eco-regional
planning approach
Conversion, Degradation, Wildlife
exploitation
Dinerstein et al.
2000
Invasive Species
What is an Invasive Species?
• A species of plant, animal, or microorganism:
– Living outside native range - an exotic
• Not all exotics are invasive
– Successfully reproduces and establishes
– Negative impacts:
• Ecological
• Economic
• Social
Pathways of Introduction
• Aquarium/pet trade and pet owners
• Plant nurseries and landscaping/horticulture
• Live seafood markets
• Shipping & boating
– Ballast
– Hull and trailer fouling
– Cargo
• Transportation
• Agriculture
• Scientific research institutions, public aquariums, and
zoos, and wildlife preserves
• Biological control
Impacts of Invasive Plant
• Ecological
– Compete, prey or parasitize native
species for resources
– Species diversity - monoculture
– Pathogens to native populations
– Ecosystem alteration
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Degrade water quality
Change fire regimes
Habitat availability
Predator/prey relationships
• Economic
– $138 billion per year
• Social
– Human health
– Quality of life: sense of place and
aesthetics
Characteristics of Invasive Species
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Reproductive
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Adaptability
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Prolific reproducers
Varying methods of reproduction
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High survival
High growth rates
Vines or rhizomes (runners)
Lack of ecological “checks and
balances”
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No natural predators
Disease resistant
Tolerate varying conditions:
Temperature
• Soil types
• Wet or dry
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Establishment
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Thrive in disturbed/stressed habitats
Alter surrounding environment
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Change soil chemistry
Modify hydrology of aquatic habitats
Crowd out natives
Sources of Information
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The Quiet Invasion:
Invasive Plants of the Galveston Bay Area
A Guide to
– Pocket field guide available
– Online field guide www.galvbayinvasives.org
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USDA Plants Database plants.usda.gov
– Texas invasive plant database
– Native plant database
– How to get involved in citizen science
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USGS NAS Database nas.er.usgs.gov
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Invasive.org www.invasive.org
– Best invasives photo collection on web
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NBII CSWGCIN cswgcin.nbii.gov
– NBII CSWGCIN regional invasives page (w/database)
Resources
Network of Conservation Educators and Practioners http://ncep.amnh.org/index.php?globalnav=home&sectionnav=home
National Project Learning Tree – www.plt.org
World Wildlife Fund – www.wwf.org and
http://www.worldwildlife.org/science/ecoregions/global200.html
Biodiversity and Conservation http://darwin.bio.uci.edu/~sustain/bio65/Titlpage.htm