Chapter 15 Biological Resources

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Chapter 15 Biological Resources
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Disappearing Frogs

• Amphibians
• Bellwether or sentinel species
• Provide early warning signs
• Many frog populations shrinking
• Worldwide problem
• Causes?

3
Frog Deformities

• Minnesota, 1995
• Other states also reporting
• Causes?

4
What Is A Species?

• Group of distinct organisms
• Breed only with each other
• How many have been identified?
• How many are there?
• New species still
  being identified
  today

5
Species Richness

• Number of different species in a community
• Varies greatly
• Depends on available niches
• Most diverse ecosystems?

6
Biodiversity

• Number and variety of Earths organisms
• Three components
• Genetic diversity
• Species richness
• Ecosystem diversity

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Why Do We Need Biodiversity?

• Ecological and agricultural processes
• Food, medicines
• Biological processes
• Organisms are interdependent

8
Ecosystem Services

• Environmental benefits provided by ecosystems
• Often taken for granted

9
Genetic Diversity

• Critical for species survival
• Crop plants
• Bred for uniformity
• Increases susceptibility to disease, pests
• Breed with more diverse strains
• Genetic engineering may help

10
Medicinal Value

• Species provide many medicines
• Rosy periwinkle childhood leukemia
• AZT
• Treat AIDS
• Derived from a sponge

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Value of Species

• Agriculture
• Provide food
• Pollination
• Industry
• Oils, lubricants
• Perfumes, dyes

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Intrinsic Value of Species

• Recreation, inspiration, spiritual solace
• Drawings, paintings, photography
• All species have a
  moral right to
  exist

13
Extinction

• Death of a life form
• Natural event
• Fate of all species
• 99 of all previous species are extinct
• Currently accelerated by human activities
• 100-1000 times natural rate

14
Extinction

• Background extinction
• Low-level
• Continuous
• Mass extinction
• Large number of species lost
• Short period of geologic time
• Causes?

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Endangered Threatened Species

• Endangered species
• Threats that may lead to extinction
• Numbers severely reduced
• Threatened species
• Declining population
• Could become endangered
• Genetic variability severely diminished

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Extinct Endangered Species

• See figure 15.5 on page 367 in the text book.

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Biodiversity Hotspots

• Relatively small areas of land
• Contain many endemic species
• At high risk from human activities

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Human Causes Of Species Endangerment

• Habitat loss
• Pollution
• Invasive species
• Overexploitation

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Habitat Loss

• Destruction, fragmentation, degradation
• Largest threat to terrestrial species
• Why is so much land being altered?
• Isolated patches often wont do
• Worldwide problem

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Habitat Loss Africa

• African elephants need lots of space
• Humans pushing into elephant territory
• Elephants cause trouble
• People cannot harm
  elephants ---gt conflict

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Pollution

• Acid precipitation
• Ozone depletion
• Climate change
• Direct or indirect poisoning
• Altered habitat from chemicals

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Invasive Species

• Foreign species that cause economic or
  environmental harm
• Often
  introduced by
  humans how?

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Zebra Mussels

• Invasive species
• Introduced from ballast water into Great Lakes
• Cluster in high density
• Eat other species food
• Cost U.S. 5 billion per year

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Overexploitation

• Large predators are pests
• Carolina parakeet
• Southern U.S.
• Farmers disliked
• Extinct
• Prairie dogs
• Ranchers dislike
• Many killed ---gt trouble for black-footed ferret

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Overexploitation

• Passenger pigeon
• Unregulated hunting
• Extinct
• White-tailed deer Canada goose almost were
  hunted to extinction
• State, national, and international laws put in
  place ? full recovery!
• Poaching
• Illegal hunting
• Many large animals

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Conservation Biology

• Study of human impacts on organisms
• Development of ways to protect biodiversity
• Two techniques
• In situ conservation preserving biodiversity in
  nature
• Ex situ conservation conserving biodiversity in
  human-controlled settings

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Protecting Habitats

• Best way to preserve biodiversity
• 3000 protected areas worldwide
• Problems
• Some too small, too isolated
• Not enough money
• Some not very species rich
• Areas of much concern
• Tropical rain forests, deserts, islands
• Brazil, Australia

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Conservation Challenges
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National Wildlife Refuge System

• Established 1903
• US Fish Wildlife Service
• Most extensive network of lands and waters
  committed to wildlife habitat
• 535 refuges
• 95 million acres
• All major U.S. ecosystems represented

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Restoration Ecology

• Study historical condition of human-damaged
  ecosystem
• Goal return it to former state
• Creates habitat
• Very expensive

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Conserving Species

• Zoos, aquaria, botanical gardens
• Collecting eggs, seeds
• Captive breeding
• Expensive
• Difficult
• May not work

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Seed Banks

• Seed collections
• 100 worldwide
• Over 3 million samples
• Kept at low temperatures
• Disadvantages
• Some cant be stored
• Expensive
• Stopping natural selection

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Endangered Species Act

• 1973
• Legal protection to listed species
• Endangered and threatened
• Species get a plan for protection
• Listing based on biology
• FWS
• NMFS

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Whats On The List?

• 2005 nearly 1300 species

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Critics Of The ESA

• Limits property owners rights
• Interferes with federally funded projects
• Impediment to economic progress
• Just keep adding more species

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Defenders Of The ESA

• Many development cases reconciled
• Has saved some species
• ESA needs strengthening
• Many species currently improving

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Future Of The ESA?

• Politically entangled since 1992
• Give property owners more rights?
• Pay property owners
  for protection?
• Protect whole ecosystems
  rather than single
  species?

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CITES

• Convention on International Trade in Endangered
  Species
• 1975
• Bans hunting, capturing, selling endangered
  species
• Regulates trade of organisms

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Make Good Choices!

• Shade-grown coffee
• Forests not cut down
• Provides habitat
• Hand-picked
• Look for organic, fair-trade brands

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Case Study Wolves In Yellowstone

• Most gone in lower 48 by 1960 why?
• 1974 listed as endangered
• 1995 reintroduced to Yellowstone
• Population has thrived
• Prey populations in check
• Ecosystem healthier

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Case Study Wolves In Yellowstone

• Ranchers oppose why?
• Compromise
• Ranchers can kill wolves that kill their
  livestock
• Federal officials can remove
  threatening wolves
• Ranchers reimbursed for losses
• What do you think?

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Homework for Thursday

• Read Wilcove and Master (2005) How many
  endangered species are there in the United
  States
• Local endangered species
• Go to www.Natureserve.org/explorer/ and find
  endangered/threatened species in your home
  county.
• At top, hover over search and click on Plants
  and animals then click location, then click US
  counties. If you are from somewhere outside the
  US, pick a US county that interests you.
• Print out results
• Pick a species that interests you. Print out and
  bring anything you feel would be useful (you can
  expand all). Summarize
• What is the species current population size?
• What is the range distibution? (where does it
  live geographically?)
• How does it reproduce? (how many offspring, how
  often, under what conditions?)
• How does it disperse? (is it territorila or does
  it have a large range? How are offspring/seeds/pol
  len distributed?)
• Does it have any specific resource requirements
  (e.g., specific prey items, soil conditions,
  etc.)?

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From Article Values of biodiversity

• Aesthetic and moral justifications (intrinsic
  value)
• Provision of products and services essential to
  human welfare
• Taxol drug from yew trees
• Indicators of ecosystem health
• Bald eagle warning of DDT danger
• Keystone species critical for functioning
  ecosystems
• Wolves in Yellowstone NP keep elk in check and
  prevent damage to sensitive habitats
• Pollinators
• Scientific breakthroughs that come from study of
  wild organisms
• Hawaiian honeycreepers clues to how
  evolution/natural selection operates in nature
• Micro-organism from hotsprings at Yellowstone NP
  provided ingredients to allow DNA fingerprinting

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From Article

• Definition
• Described species a species that is known to
  science. That is, it has had a formal description
  published in a peer-reviewed scientific outlet
  (book, journal)
• 942 species listed as endangered or threatened by
  the Endangered Species Act
• Estimated 14000-35000 of described species
  probably endangered
• (Table 3 in article lists 24480 species as being
  endangered for the well-studied groups 20 of
  all species!)

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Causes of endangerment

• Overall
• Habitat loss (85 of species)
• Non-indigenous (invasive, introduced species
  (49)
• Pollution (24
• Over-exploitation (17)
• Disease (3)
• Causes differ by taxonomic group/ecosystem

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Conservation strategies

• How to conserve endangered species if we dont
  even know what species are there, let alone which
  are endangered?
• Coarse filter approach
• Identify and protect biodiversity hotspots
• Communities/ecosystems with many species
• Fine filter approach
• More surveys of species distributions to identify
  which particular species are in need of dedicated
  protection and management