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 =