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Conservation of Biodiversity
VAN ROEKEL
IB BIO II
Assessment Statements G.4.1 Explain the use of biotic indices and indicator species in monitoring environmental change
G.4.2 Outline the factors that contributed to the extinction of one named animal species
G.4.3 Outline the biogeographical features of nature reserves that promote conservation of diversity
G.4.4 Discuss the roles of active management techniques in conservation
G.4.5 Discuss the advantages of in situ conservation of endangered species (terrestrial and aquatic reserves)
G.4.6 Outline the use of in situ conservation measures, including captive breeding of animals, botanic gardens, and seed banks
Indicator Species Indicator Species: species that are very sensitive to environmental changes
◦ Species will not be present in areas of high pollution◦ Absence/presence of indicator species helps identify clean/polluted
environments◦ Lichens – sensitive to air pollution and presence of mercury/lead◦ Macroinvertebrates – found in rivers and streams, sensitive to water
pollution
Biotic Index Measures the health of an ecosystem by measuring the number of species tolerant to pollution and the number of species intolerant to pollution
◦ The more intolerant species the cleaner the environment
Extinction When environmental changes occur, the new selection pressures can lead to the extinction of previously successful animals
Factors that contribute to extinction◦ Habitat Destruction◦ Pollution◦ Overfishing or Overhunting◦ Climate Changes◦ Invasive Species
https://www.youtube.com/watch?v=hDbz2dpebhQ
Extinction of Dodo Caused by arrival of Dutch to environment in 1600s
◦ Deforestation and habitat loss◦ Hunting for food◦ Invasive Species, rats, dogs, cats from ships
Lack of fit characteristics◦ Flightless◦ Short Legs◦ No behavioral adaptation to avoid predation
Nature Reserves Promote Biodiversity
Areas of aquatic and terrestrial ecosystems that are protected by law to conserve biodiversity
Nature Reserves are beneficial because◦ Control Invasive Species◦ Control Human exploitation◦ Legally protect endangered species◦ Opportunities for research◦ Restoration of degraded areas
Nature Reserves & size Nature reserves have very large areas
◦ Larger Habitats◦ More resources & breeding sites◦ More niches◦ Allows for migration◦ Establishes different ecosystems◦ More biodiversity
Smaller habitats have higher risks of extinction from unexpected factors
Nature Reserves & Edge Effect
Ecology at edge of ecosystems is different from center habitats
Disturbances from outside extends into ecosystem◦ Edges of forest have fewer trees, more sunlight and wind, less moisture.◦ Organisms have more competition from other species
Edge effect is controlled in reserves
Nature Reserves and Corridors
Greenbelts, hedgerows, and even tunnels under highways can provide corridors that connect otherwise isolated habitats
Allows species to expand over larger areas
Problems include◦ Narrow corridors lead to exposure to predation◦ Invasive species can enter habitat◦ Corridors can cause controversy with humans
Management of Reserves
Active intervention occurs when humans intervene to restore areas and protect natural habitats in a nature reserve
Includes:◦ Restoration – restore land to natural state, can include clearing existing
species and replanting ◦ Recovery of threatened species – maintains habitats of endangered species
and reintroduction◦ Removal of introduced species – removal of invasive species that have
dominated environment◦ Legal Protection – prevent activity that harms native animals and plants,
such as development and pollution◦ Funding and prioritizing – used to fund preserves
In situ conservation Keeps organisms in the situation they belong and protect them by:
◦ Maintaining the original habitat◦ Defending from predators◦ Removing and preventing invasive species◦ Having large areas to maintain large populations◦ Large populations maintain genetic diversity
Ineffective when:◦ Species is too endangered◦ Small populations can’t maintain genetic diversity◦ Uncontrollable destructive forces (human incursion, invasive species, natural
disasters)
Ex situ Conservation Usually a last resort if species can not safely remain in natural habitat, or population is too small
Accomplished in variety of ways◦ Captive Breeding◦ Cultivations of plants in botanical gardens◦ Storing seeds in seed bank
Captive Breeding Many zoos have facilities dedicated to captive breeding
Goal is to increase reproductive output to ensure survival of offspring◦ Artificial insemination◦ Embryo transfer to surrogate◦ Cryogenic eggs◦ Human raised young◦ Keeping a pedigree (minimize inbreeding)
Problem - Difficulty reintroducing organisms into natural environment
Botanical Gardens & seed banks
Botanical Gardens◦ Easy care and breeding◦ 80,000 plants are grown outside of natural environment
Seed Banks◦ Seeds kept in cold, dark conditions◦ Prevents germination, allows for later use (decades)◦ 10,000 – 20,000 different species have seeds stored in seed banks
Population EcologyVAN ROEKEL
IB BIO II
Assessment Statements G.5.1 Distinguish between r-strategies and k-strategies
G.5.2 Discuss the environmental conditions that favor either r-strategies or k-strategies
G.5.3 Describe one technique used to estimate the population size of an animal species based on mark-release-recapture method
G.5.4 describe the methods used to estimate the size of commercial fish stocks
G.5.5 outline the concept of maximum sustainable yield in the conservation of fish stock
G.5.6 Discuss international measures that would promote the conservation of fish
r-strategy vs. k-strategy Two strategies for survival and reproduction
r-strategy makes the use of disposable offspring, organisms produce hundreds or thousands of offspring and don’t care for them after birth
k-strategy occurs when parents have few offspring and invest time and energy into raising, nurturing and protecting offspring
r-strategy vs. k-strategyCharacteristic r-strategy k-strategy
Life span Short Long
# of offspring Many Few
Onset of maturity Early Late- after long period of parental care
Body size Small Large
Reproduction Once during lifetime
More than once during lifetime
Parental care None Very likely
Environment Unstable Stable
Capture-mark-recapture Method used to estimate the number of animals in an ecosystem
Capture some of population, mark and release them
Second sample taken consisting of marked and unmarked individuals
Proportion of marked to unmarked organism is same as proportion of original marked to whole population
Formulan3
n2
n1
N
N1 x n2
n3N =
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