Download Biodiversity (Week Eight)

Biodiversity
Environmental Science Notes
Series
What is Biodiversity?
• Species Richness is another term for
biodiversity
• Density is an important factor in terms of
biodiversity
• Carrying capacity: resource availability is
important (Tillman curve)
Niche
• The role of an organisms within its
environment (habitat) that is specific.
• Gause’s competitive exclusion theory – no
two organisms (populations) can occupy
the same niche indefinitely (Andrews.edu).
• Niche is important in terms of competition.
Species Abundance?
• The amount of a particular species in a
given habitat is important, this is
abundance.
• Sometimes this does not support species
richness if the species out-competes
others species.
Biodiversity
• According to Peter Raven (2007) there are
approximately 1.5 million known species
on earth with a high extinction rate.
• There may be 8 – 10 million species on
earth today, but not much is known about
the lower taxa.
• Biodiversity is being impacted by humans
at an unprecedented rate of extinction of
up to 200 species per day.
Competition
• There are a number of ways in which a
species competes for resources:
1. Exploitation: this is when a species
can utilize resources better than other
species (i.e. Aureococcus)
2. Interference: when a species can
create its own environment and
manipulate it for its advantage (i.e. Sour
weed)
Ecology
• Ecology is a young field (started in the
1950’s), exploring the role of organisms
within their environments and how it
relates to survival.
• Ecology takes into account habitat,
environmental factors, biological functions
and physical conditions.
Population Estimates
• Use basic population models…
Interspecies: Margelef, Menhenick,
Jaccard’s indices
Inter/Intraspecies: Simpson’s Index
Island Biogeography
• Robert MacArthur and Edward O. Wilson,
theorized about space and resources
looking at islands.
• They hypothesized that islands further
from a mainland would have less species
diversity than those closer.
• They also hypothesized that larger islands
would support more diversity than smaller
islands.
Sustaining Wild Species
• Over 90% of today’s crops are
domesticated and basically 4 crop types
provide a majority of the world its food
requirement.
• Over 80% of the world needs plants for
medicinal purposes.
Sustaining Wild Species?
• Is survival of the human species a key to
survival of other species?
• We look at things from an anthropogenic
view.
• It is thought that over 1 million species live
in the rainforests (known) with an
extinction rate of 2% per year!
Species protection categories
• Endangered – reduced mating pairs to
the point where populations cannot sustain
themselves (Kemp’s ridley sea turtle)
• Threatened – declining in numbers, but
must be protected (Osprey)
• Concern – Decline, possibly due to
habitat loss or resource limitations
Protection
• Endangered Species Preservation Act (1973):
Species are listed under Federal and
Statewide basis. Therefore, they could
receive protection under different categories.
American alligator – Federal
Threatened, varies statewide
IUCN: Red List Program
• The International Union for the
Conservation of Nature established a
program through the United Nations for
global protection of species
• Under the Red List Program
(www.iucnredlist.org) has a well organized
system of species rankings.
IUCN Red LIST 2007
Protection
• Enforcement of the Endangered Species
Act is a Federal Mandate and falls under
the following…
– U.S. Fish and Wildlife Service
– National Oceanic & Atmospheric
Administration, National Marine
Fisheries
U.S. Fish & Wildlife
• Department of the Interior.
• Responsible for all beaches, inland
waters, except Great Lakes.
• Species management, control and
manage lands that are moderatelyrestricted (over 500 refuges and
rangelands).
“NOAA Fisheries Service conserves,
protects, and manages living marine
resources in a way that ensures their
continuation as functioning components
of marine ecosystems, affords economic
opportunities, and enhances the quality
of life for the American public” (NOAA
2007).
NOAA
• National Estuarine Research Reserve
Program
• Sanctuaries and Protected Areas (called
Marine Protected Areas
• Fisheries Quotas and Enforcement
Other players in management
• Multiple Use Lands..
National Forests which include over 150
Forests and 19 grasslands managed
through the U.S. Forest Service
Other players in management
• Multiple Use Lands…
• The largest is the Bureau of Land Management
which includes prairies, deserts, scrub forests
and open spaces mostly in the western U.S.
Other players in management
• Restricted Use Lands
The National Park Service has over 370 units and
50+ major parks throughout with close to 50%
in the wilderness (www.nps.gov).