Chapter 12 Sustaining Biodiversity: The Species Approach.
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Transcript of Chapter 12 Sustaining Biodiversity: The Species Approach.
Chapter 12Chapter 12
Sustaining Biodiversity:Sustaining Biodiversity:
The Species Approach The Species Approach
Key ConceptsKey Concepts
Human effects on biodiversityHuman effects on biodiversity Importance of biodiversityImportance of biodiversity How human activities affect How human activities affect
wildlifewildlife Management of wildlifeManagement of wildlife
67%Secure orapparently
secure
1%Other
16%Vulnerable
8%Imperiled
7%Critically imperiled
1% Probably extinct
US Diversity
What Increases What Increases Biodiversity?Biodiversity?
Physically diverse habitatPhysically diverse habitatModerate environmental Moderate environmental
disturbancedisturbanceSmall variations in conditionsSmall variations in conditionsMiddle stages of ecological Middle stages of ecological
successionsuccession
What Decreases What Decreases Biodiversity?Biodiversity?
Environmental stressEnvironmental stress Large environmental disturbanceLarge environmental disturbance Extreme environmental conditionsExtreme environmental conditions Severe limiting factorsSevere limiting factors Introduction of alien (exotic) Introduction of alien (exotic)
speciesspecies Geographic isolationGeographic isolation
Projected Status of Biodiversity1998–2018
Critical and endangered Threatened Stable or intact
ANTARCTICA
NORTHAMERICA
EUROPE
AFRICA
ASIA
SOUTHAMERICA AUSTRALIA
PacificOcean
Antarctic Circle
PacificOcean
Tropic of Cancer
Tropic of CapricornIndianOcean
AtlanticOcean
150°90°60°E0°30°W90°120°150°0°
60°
30°N
30°S
60°
Arctic CircleArctic Circle
Strategies for Protecting Species
Species ExtinctionSpecies Extinction
Local ExtinctionLocal Extinction: when a species is no : when a species is no longer found in the area that it once longer found in the area that it once inhabited (but is still found elsewhere inhabited (but is still found elsewhere in the world)in the world)
Ecological ExtinctionEcological Extinction: so few members : so few members of a species are left that it can’t play of a species are left that it can’t play its ecological roleits ecological role
Biological ExtinctionBiological Extinction: species is not : species is not found anywhere on earth (permanent)found anywhere on earth (permanent)
Endangered and Threatened Endangered and Threatened SpeciesSpecies
Endangered SpeciesEndangered Species: so few : so few survivors that the species could soon survivors that the species could soon become extinctbecome extinct
Threatened SpeciesThreatened Species: still abundant in : still abundant in its natural range but is likely to its natural range but is likely to become endangered due to declining become endangered due to declining numbersnumbers
Extinction RisksExtinction Risks
Low reproductive rateLow reproductive rate (K-strategists): (K-strategists): blue whale, giant pandablue whale, giant panda
Specialized nicheSpecialized niche: giant panda: giant panda Narrow distributionNarrow distribution: island species: island species Feeds at high trophic levelFeeds at high trophic level: Bengal : Bengal
tiger, bald eagletiger, bald eagle RareRare: island species, orchids: island species, orchids Commercially valuableCommercially valuable: elephant: elephant
How Do We Estimate Extinction How Do We Estimate Extinction Risks?Risks?
Population viability analysis (PVAPopulation viability analysis (PVA): ): risk assessment to predict whether a risk assessment to predict whether a population will persist for a certain # population will persist for a certain # of generationsof generations
PVA is based onPVA is based on: resource needs, : resource needs, current and predicted habitat current and predicted habitat conditions, genetic variability, conditions, genetic variability, interactions with other species, interactions with other species, reproductive ratesreproductive rates
Continued…Continued…
Minimum viable population (MVP)Minimum viable population (MVP): : smallest number of individuals smallest number of individuals necessary for the survival of a necessary for the survival of a population in a regionpopulation in a region
Minimum dynamic area (MDA)Minimum dynamic area (MDA): the : the minimum area of habitat needed to minimum area of habitat needed to maintain the MVPmaintain the MVP
Why Should We Care About Why Should We Care About Biodiversity?Biodiversity?
Humans value nature in different Humans value nature in different waysways
Instrumental valueInstrumental value: usefulness to us: usefulness to us Intrinsic valueIntrinsic value: because they exist, : because they exist,
regardless of useregardless of use UtilitarianUtilitarian (use): goods, services, (use): goods, services,
recreationrecreation NonutilitarianNonutilitarian (nonuse): aesthetic (nonuse): aesthetic
Value of Nature
Instrumental Intrinsic
Utilitarian Nonutilitarian
(human centered) (species orecosystemcentered)
Goods
Ecological services
Information
Recreation
Existence
Aesthetic
Causes of Depletion of Wild Causes of Depletion of Wild SpeciesSpecies
Human population growthHuman population growthFailure to value the Failure to value the
environmentenvironment Increasing resource useIncreasing resource usePovertyPoverty
Overfishing
Habitatloss
Habitatdegradation
Introducingnonnativespecies
Commercialhunting
Sale ofexotic pets
anddecorative
plants
Predatorandpest
control
Pollution
Climatechange
Basic Causes
• Population growth• Rising resource use• No environmental
accounting• Poverty
Type of Nonnative Organism Annual Losses and DamagesCrop disease
Crop weeds
Rats
Feral cats and outdoor pet cats
Crop insects
Livestock diseases
Forest insects and diseases
Zebra mussels
Common pigeon
Formosan termite
Fishes
Asian clam
Feral pigs
Starlings
Fire ant
$23.5 billion
$23.4 billion
$19 billion
$17 billion
$14 billion
$9 billion
$4.8 billion
$3 billion
$1.1 billion
$1.1 billion
$1.1 billion
$1.1 billion
$0.8 billion
$0.8 billion
$0.6 billion
Damage from
NonnativeSpecies
Characteristics ofSuccessful
Invader Species
• High reproductive rate, short generation time (r-selected species)
• Pioneer species
• Long lived
• High dispersal rate
• Release growth- inhibiting chemicals into soil
• Generalists
• High genetic variability
Characteristics ofEcosystems Vulnerable
to Invader Species
• Similar climate to habitat of invader
• Absence of predators on invading species
• Early successional species
• Low diversity of native species
• Absence of fire
• Disturbed by human activities
What Can Be Done to Reduce What Can Be Done to Reduce Threat from Nonnative Threat from Nonnative
Species?Species? Identify characteristics that make Identify characteristics that make
species successful invaders and use species successful invaders and use this information to screen out this information to screen out invadersinvaders
Increase inspections of goods coming Increase inspections of goods coming into a countryinto a country
Pass laws to ban the transfer of Pass laws to ban the transfer of harmful invader speciesharmful invader species
Biome % of Area Disturbed
Temperate broadleaf forests
Temperate evergreen forests
Temperate grasslands
Mixed mountain systems
Tropical dry forests
Subtropical and temperate rain forests
Cold deserts and semideserts
Mixed island systems
Warm deserts and semideserts
Tropical humid forests
Tropical grasslands
Temperate boreal forests
Tundra
94%
94%
72%
71%
70%
67%
55%
53%
44%
37%
26%
18%
0.7%
HabitatDisturbance
by Biome
Hunting and PoachingHunting and Poaching
Wild African ElephantWild African Elephant
1970: 2.5 million1970: 2.5 million Today: 300,000Today: 300,000 Killed for tusks (worth about $500-1500)Killed for tusks (worth about $500-1500) Bleed to deathBleed to death 1989 ban on sale of ivory from 1989 ban on sale of ivory from
elephantselephants Caused increased killing of walruses Caused increased killing of walruses
and hippos for ivoryand hippos for ivory
DO NOT POST TO INTERNET
Protecting Wild Species IProtecting Wild Species I
BioinformaticsBioinformatics: managing, analyzing, : managing, analyzing, and communicating biological and communicating biological informationinformation
Involves: 1. building computer Involves: 1. building computer databases 2. developing computer tools databases 2. developing computer tools to analyze the information 3. to analyze the information 3. communicating the informationcommunicating the information
Example: Example: Species 2000- Species 2000- global research global research project with the goal of providing project with the goal of providing information about all species on earthinformation about all species on earth
Protecting Wild Species IIProtecting Wild Species II
International TreatiesInternational Treaties Convention on International Trade in Convention on International Trade in
Endangered SpeciesEndangered Species (CITES) 1972 (CITES) 1972 Signed by 152 countriesSigned by 152 countries Lists 900 species that cannot be Lists 900 species that cannot be
commercially tradedcommercially traded Restricts international trade of Restricts international trade of
29,000 other at-risk species29,000 other at-risk species
Protecting Wild Species IIIProtecting Wild Species III
National LawsNational Laws Lacey Act of 1900Lacey Act of 1900: prohibits : prohibits
transportation of live or dead animals transportation of live or dead animals (or their parts) across state borders (or their parts) across state borders without a permitwithout a permit
Endangered Species Act of 1973Endangered Species Act of 1973: : illegal for Americans to import or illegal for Americans to import or trade any product made from an trade any product made from an endangered or threatened speciesendangered or threatened species
Protecting Wild Species IVProtecting Wild Species IV
Habitat Conservation PlansHabitat Conservation Plans Compromise between endangered Compromise between endangered
species and private landownersspecies and private landowners Landowners are allowed to kill a certain Landowners are allowed to kill a certain
# of endangered species on private land # of endangered species on private land in exchange for taking steps to protect in exchange for taking steps to protect the speciesthe species
Possible stepsPossible steps: setting aside a preserve for : setting aside a preserve for the species, paying to relocate the the species, paying to relocate the species, paying for government buy species, paying for government buy habitat elsewherehabitat elsewhere
Other Approaches to Protecting Other Approaches to Protecting Wild SpeciesWild Species
Wildlife refuges and protected Wildlife refuges and protected areasareas
Gene banks (storing plant seeds), Gene banks (storing plant seeds), botanical gardens (cultivation of botanical gardens (cultivation of rare and endangered plants), and rare and endangered plants), and farms (raise for commercial sale)farms (raise for commercial sale)
Zoos and aquariumsZoos and aquariums
Wildlife ManagementWildlife Management
Laws regulating hunting and Laws regulating hunting and fishingfishing
Harvest quotasHarvest quotasPopulation management plansPopulation management plans Improving habitatImproving habitatLaws for migrating speciesLaws for migrating species