Transcript Lumbricus terrestris

Overexploitation
Tokyo Tuna Market
Types of Overexploitation
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Commercial exploitation
Subsistence exploitation
Recreational exploitation
Incidental exploitation
Indirect exploitation
Pet and garden market
Commercial exploitation
• Potential market for wild products is
enormous
• Given market, people will exploit wild
species for financial gain
• Domestic substitutes for wild products are
not identical in value
• Market price for wild products increases as
product becomes rarer
• Wild resources are communal resources
owned by no one or everyone
Morel Mushrooms for Sale
Coral harvested for jewelry
Rhinoceros exploitation
Rhino horn
Products –
Dagger market
in Yemen
Rhino Horn in Traditional Medicine
Wild Blueberries
Wild Salmon
Egret plumes and feathered hat
Tragedy of the Commons
Japanese Whaling Ships
Subsistence exploitation
Subsistence Fishing
Ojibway wild rice harvesting
Recreational exploitation
Hunting as Recreation
Shell Collection
Gordon Alcorn
Photographic safari
Cheetah on Land Rover
Dive boat damage to coral reefs
Incidental exploitation
Trawling
Kemp’s Ridley Sea Turtle
Shrimp net with TED – turtle
exclusion device
Indirect exploitation
Overgrazing
Domestic cats preying on small birds
Pet and Garden Market
Gray Parrots in Smuggler’s Crate
Tropical Fish for Aquarium Trade
Cactus Market
Saguaro Cactus
Consequences of Overexploitation
1. Population Effects
- Reduction in population size
- Age structure
- Sex ratio
- Genetic structure
2. Ecosystem Effects
Age Structure: A – fish in typical population
B – fish taken by fishing
Sex Ratios – The Fisher
Fisher Distribution
Genetic Structure – Coho Salmon
Genetic Structure – Coho Salmon
Ecosystem Structure – Loss of
Large Trees
Giant Redwood
Redwood Forest in the Air
Planting Sequoias
Ecosystem Structure – Loss of Snags
Loss of Keystone Species - Sea Otter
with Sea Urchin
Loss of Keystone Species - Glyptodont
Maclura pomifera – Osage Orange
Exotic Species
Mrs. Black Horse, Cheyenne Nation,
and dog travois
American Chestnut
Cracking From Chestnut Blight
Exotic Species
• Conservation biologists typically call
introduced species “exotic species” species which live outside their natural
range
• Botanists typically refer to exotic plants as
alien species
• Other terms you may see include biological
invaders, introduced species, invasive
species, non-indigenous species, non-native
species (my preferred term)
How Do Exotic Species Get
Dispersed?
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Stowaways
Subsistence and Commerce
Recreation
Whimsy or aesthetics
Science
Biological Control
Norway Rat as ship rat
Earthworms and pre-exotic
distribution
Lumbricus terrestris
Cars transport seeds via
mud stuck to car
Ballast Water Discharge
Commerce and Subsistence
Commerce and Subsistence
Monterey Pine
Blue Gum Eucalyptus
Feral Pig - Florida
Bighead Carp
Carp Jumping
Recreation - Brown Trout
Ring-necked Pheasant
Chukar
Red Deer – New Zealand
Whimsy or Aesthetics –
European Starling
House Sparrow
Exotic plants in New Zealand
• Native flora of 2065
species
• 24,774 documented
introduced alien species
• About 2200 exotics
have become
established (naturalized)
Multiflora Rose
Tree of Heaven - Ailanthus
Light blue – counties where
Ailanthus is present
Scotch Broom
Walking Catfish
Cherry Headed Conures
in San Francisco
Monk Parrots – Chicago, Harold
Washington Park and Hyde Park
Science - Gypsy Moth
Africanized Honey Bees
Movement of Africanized Honey Bees
Movement of Africanized Honey Bees
Biocontrol
Klamath Weed – aka – St. John’s Wort
Chrysolina beetle
Prickly Pear Hedge - Tunisia
Prickly pear in Australia – before control
Cactoblastis cactorum
Prickly pear – same location after control
Red Fox - Australia
With native Bobuck possum
Red fox - Australia