Species Diversity and Preservation ISpecies Diversity and Preservation I

Potential Test QuestionsPotential Test Questions

1.1. Distinguish threatened, endangered, and extinct species. Distinguish threatened, endangered, and extinct species. Explain four characteristics common to many Explain four characteristics common to many endangered species.endangered species.

2.2. Discuss the main human causes for endangered species.Discuss the main human causes for endangered species.

3.3. Discuss ways to slow or stop the decline in species Discuss ways to slow or stop the decline in species diversity.diversity.

Factors Affecting Biological ResourcesFactors Affecting Biological Resources

Natural Processes (e.g., fires)Natural Processes (e.g., fires)

Land Use (e.g., urban development)Land Use (e.g., urban development)

Water Use (e.g., hydroelectric)Water Use (e.g., hydroelectric)

Climate Change (e.g., global warming)Climate Change (e.g., global warming)((http://observer.guardian.co.uk/international/story/0,6903,1153513,00.html ))

Nonindigenous SpeciesNonindigenous Species

Environmental Contaminants (e.g., oil spills)Environmental Contaminants (e.g., oil spills)

Harvest (e.g., overfishing)Harvest (e.g., overfishing)

Species Diversity - TerrestrialSpecies Diversity - Terrestrial

Species Species DiversityDiversity

DefinitionsDefinitions

Extinction:Extinction: the irreversible loss or ‘death’ of a species.the irreversible loss or ‘death’ of a species.

Endangered species (ESA):Endangered species (ESA): a a species in imminent danger species in imminent danger of extinction throughout all of extinction throughout all or a significant portion of its or a significant portion of its range. range. (What is a species?) (What is a species?)

Threatened species:Threatened species: a species a species

that is likely to become that is likely to become endangered in all or a endangered in all or a significant portion of its significant portion of its range.range.

Species DiversitySpecies Diversity

Characteristics of Endangered Characteristics of Endangered SpeciesSpecies

• Extremely small rangeExtremely small range - lily on single - lily on single hilltop near SF.hilltop near SF.

• Large territoriesLarge territories - California condor. (+ - California condor. (+ issue of Minimum Viable Populations)issue of Minimum Viable Populations)

• Living on islandsLiving on islands - endemics (living - endemics (living nowhere else); evolved in isolation from nowhere else); evolved in isolation from predators, disease, and competition.predators, disease, and competition.

• Low biotic potentialLow biotic potential - blue whales. - blue whales.• Specialized breeding areasSpecialized breeding areas - green sea - green sea

turtles.turtles.• Specialized feeding habitatsSpecialized feeding habitats - pandas and - pandas and

bamboo.bamboo.

ExtinctionExtinction

Mass ExtinctionsHistoric Period Time (MYA) Effects _

Ordovician 444 25% of all families extinctDevonian 370 19% of all families extinctPermian 250 54% of families, 90% of species extinctTriassic 210 23% of families, 50% of species extinctCretaceous 65 17% of families, 50% of species extinct (including

dinosaurs but not mammals)Quaternary present 1/3 to 2/3 of all species extinct if present trends

continue

If extinction is a natural process, why should we be If extinction is a natural process, why should we be concerned about extinction?concerned about extinction?

Human-based ExtinctionHuman-based Extinction:

Human disturbance dominates many landscapes, makingHuman disturbance dominates many landscapes, makingthe processes of many ecosystems human-dominatedthe processes of many ecosystems human-dominated.

Species Diversity - Loss of EcosystemsSpecies Diversity - Loss of Ecosystems

Effects of Effects of Human Human

Population on Population on DiversityDiversity

Human-based ExtinctionHuman-based Extinction:

:We affect species through:We affect species through:

1.1. Habitat DestructionHabitat Destruction2.2. Hunting and FishingHunting and Fishing3.3. Predator ControlPredator Control4.4. PollutionPollution5.5. Genetic AssimilationGenetic Assimilation6.6. Diseases Diseases 7.7. Exotic SpeciesExotic Species

Introductions

Species Diversity - Health of Species Diversity - Health of EcosystemsEcosystems

Species Diversity - Loss of EcosystemsSpecies Diversity - Loss of Ecosystems

Habitat DestructionHabitat Destruction:: conversion of wilderness into conversion of wilderness into human-based habitat; mainly for farming, range use, and human-based habitat; mainly for farming, range use, and forestry, but also for urban centers. forestry, but also for urban centers.

Iowa has lost much greater than 90% of its wetlands.Iowa has lost much greater than 90% of its wetlands.

FragmentationFragmentation can cause forests (or can cause forests (or prairies) to slowly become small islands of prairies) to slowly become small islands of wooded area that can be too small to wooded area that can be too small to maintain breeding populations. maintain breeding populations.

Fragmentation eliminates the Fragmentation eliminates the core core environmentenvironment, expanding the amount of edge , expanding the amount of edge available for weedy species to invade, and available for weedy species to invade, and eliminates the environment some species eliminates the environment some species need to survive.need to survive.

Critical Size of an EcosystemCritical Size of an Ecosystem

Amazonia example:

Thomas Lovejoy created patches of various sizes (from 1 to 1000 ha and a 10,000 ha 'mainland'). A hectare (ha) = 10,000 sq kilometers or ~ 2.5 acres

Results from Lovejoy’s Amazonia StudiesResults from Lovejoy’s Amazonia Studies

A guild of A guild of insectivorous birdsinsectivorous birds (that feed on insects (that feed on insects fleeing swarming army ants) disappeared in 1, 10 fleeing swarming army ants) disappeared in 1, 10 hectare, and some 100 ha fragments plots. hectare, and some 100 ha fragments plots.

PollinatorsPollinators, euglossine bees, would not cross 100 m , euglossine bees, would not cross 100 m cleared strips, so population biology of at least 30 plant cleared strips, so population biology of at least 30 plant families dramatically affected. families dramatically affected.

Results from Lovejoy’s Amazonia StudiesResults from Lovejoy’s Amazonia StudiesRain forest fragments in central Rain forest fragments in central Amazonia were experienced a Amazonia were experienced a dramatic loss of above-ground tree dramatic loss of above-ground tree biomass that was not offset by biomass that was not offset by recruitment of new trees. These losses recruitment of new trees. These losses were largest within 100 meters of were largest within 100 meters of fragment edges, where tree mortality fragment edges, where tree mortality was sharply increased by was sharply increased by microclimatic changes and elevated microclimatic changes and elevated wind turbulence. Permanent study wind turbulence. Permanent study plots within 100 meters of edges lost plots within 100 meters of edges lost up to 36% of their biomass in the first up to 36% of their biomass in the first

10 to 17 years after fragmentation.10 to 17 years after fragmentation.

Results from Lovejoy’s Amazonia StudiesResults from Lovejoy’s Amazonia Studies

Dung and carrion feeding beetles responded similarly Dung and carrion feeding beetles responded similarly to other insects, so the to other insects, so the decomposition processdecomposition process slowed. slowed. Much of the Much of the primate diversityprimate diversity went almost went almost immediately extinct in the isolated fragments. immediately extinct in the isolated fragments.

Only 7 of 20 mammal species present in reserve areas Only 7 of 20 mammal species present in reserve areas persisted in the first isolated fragments, and many of persisted in the first isolated fragments, and many of those that persisted were those capable of surviving in those that persisted were those capable of surviving in disturbed areas or secondary vegetation.disturbed areas or secondary vegetation.

Minimum Viable PopulationsMinimum Viable PopulationsPopulations that are large enough that inbreeding does not Populations that are large enough that inbreeding does not cause the species to go extinct.cause the species to go extinct.

If Minimum Viable PopulationsIf Minimum Viable Populations are not maintained, the are not maintained, the species cannot survive. (Plus, chance events have a greater species cannot survive. (Plus, chance events have a greater likelihood of eliminating a species that is already reduced in likelihood of eliminating a species that is already reduced in numbers.)numbers.)

Greater Prairie Greater Prairie ChickenChicken

Planned Planned reservesreserves on an on an ecosystem basisecosystem basis. For example, in . For example, in Yellowstone National ParkYellowstone National Park (for watershed and wildlife (for watershed and wildlife resources), more land would have to be added. resources), more land would have to be added.

Protected ForestsProtected Forests

Preservation and Park Usage in the U.S.A.Preservation and Park Usage in the U.S.A.

Threats to Parks:Threats to Parks: 1.1. Islands of natureIslands of nature

surrounded by destructive surrounded by destructive land use. land use.

2. Roads2. Roads, trails (especially , trails (especially ATVs and off-road ATVs and off-road vehicles).vehicles).

3. Visitor impact:3. Visitor impact: Yosemite Yosemite National ParkNational Park - 25,000 - 25,000 visitors for a 3-day weekend visitors for a 3-day weekend (cars, laundries, concessions, (cars, laundries, concessions, guest rooms, etc).guest rooms, etc).

Habitat destruction does not Habitat destruction does not end just because land is placed end just because land is placed into a reserve/preserve/park.into a reserve/preserve/park.

CorridorsCorridorsStrips of habitat running between patches of habitat.Strips of habitat running between patches of habitat.

Used to Used to allow movement of allow movement of speciesspecies from one area to from one area to another to help maintain another to help maintain genetic exchange and prevent genetic exchange and prevent extinction. extinction.

However, corridors can also However, corridors can also be a be a riskrisk because they may act because they may act as a as a corridor forcorridor for disease, disease, invasive species, or as trapsinvasive species, or as traps for the species you are trying for the species you are trying to protect.to protect.

Hunting and FishingHunting and Fishing

Consider the large Pleistocene mammals - Consider the large Pleistocene mammals - extinctions extinctions probably caused by human hunting - mammoths, mastadons probably caused by human hunting - mammoths, mastadons wooly rhinos, and ground sloths. wooly rhinos, and ground sloths.

Hunting and FishingHunting and Fishing

In the recent past, whales have been hunted to the brink of In the recent past, whales have been hunted to the brink of extinction. Bison were once in the 10’s of millions, but extinction. Bison were once in the 10’s of millions, but were reduced to less than 1000 individuals. were reduced to less than 1000 individuals.

Passenger pigeons - now Passenger pigeons - now extinct; once over 3 billion.extinct; once over 3 billion.

Predator/Pest ControlPredator/Pest Control

American alligator: top predator - keeps gar populations in check. creates habitat diversity - islands created by nest moundsgator trails - prevent marsh establishmentgator holes - provide habitat for other species in drought

Involves top Involves top predators predators ((keystone keystone speciesspecies). ). Wolves, Wolves, mountain lions, mountain lions, gators.gators.

PollutionPollution

Amphibians as early Amphibians as early warning indicators. In warning indicators. In North America, and world-North America, and world-wide, amphibian wide, amphibian populations have drastically populations have drastically declined and deformities declined and deformities have increased.have increased.

PollutionPollution

Environmental estrogensEnvironmental estrogens: (DDT, PCBs, Dioxins) : (DDT, PCBs, Dioxins) disrupt hormones; impact fish, reptilian, and disrupt hormones; impact fish, reptilian, and amphibian reproduction. amphibian reproduction.

Acid precipitation: Acid precipitation: alters pH of water, thereby affecting alters pH of water, thereby affecting

species. species.

Ozone depletionOzone depletion (due to CFCs): cause increased UV (due to CFCs): cause increased UV light penetration and so cause higher mutation rates, light penetration and so cause higher mutation rates, thereby affecting populations. thereby affecting populations.

Global warming: temperature alterations can Global warming: temperature alterations can cause cause population declines.population declines.

Species Diversity - Loss of EcosystemsSpecies Diversity - Loss of Ecosystems

Genetic AssimilationGenetic Assimilation

Classic definition is that genes of species at low population numbers are at risk of being swamped if they hybridize with close relatives.

With the use of genetically modified (GM) species in farming, for example, could include the assimilation of native species into closely related GM species.

Genetic AssimilationGenetic Assimilation

Red wolf: predator control and destruction of mature woodland caused a reduction in range and population size.

By 1970s, the species had dwindled to a single population in eastern Texas, and this population is threatened by interbreeding with the close relative, the coyote (Canis latrans).

DiseaseDisease

Dutch elm disease was first found in the United States in Dutch elm disease was first found in the United States in Ohio in 1930. It has now spread throughout North Ohio in 1930. It has now spread throughout North America and has destroyed over half the elm trees in the America and has destroyed over half the elm trees in the

northern United States.northern United States. Dutch elm disease is caused by the Dutch elm disease is caused by the fungus fungus Ophiostoma ulmi Ophiostoma ulmi which is transmitted by two which is transmitted by two species of bark beetles or by root grafting.species of bark beetles or by root grafting.

Dutch elm disease owes its name to Dutch elm disease owes its name to the fact that it was first identified in the fact that it was first identified in the Netherlands in 1921. the Netherlands in 1921.

Powdery Mildew on Dogwoods Powdery Mildew on Dogwoods (Dogwood Anthracnose)(Dogwood Anthracnose)

Powdery mildew, which is caused by the fungus Powdery mildew, which is caused by the fungus Microsphaeria penicillataMicrosphaeria penicillata..

Probably introduced into the United Probably introduced into the United States near Connecticut and Washington States near Connecticut and Washington State simultaneously in the mid-1970s. State simultaneously in the mid-1970s. Although it entered the U.S.A. at two Although it entered the U.S.A. at two separate points, genetic analysis has separate points, genetic analysis has shown that the causal organism is the shown that the causal organism is the same. However, the origin of this same. However, the origin of this pathogen remains unknown, as it has yet pathogen remains unknown, as it has yet to be identified on any species of to be identified on any species of dogwood occurring outside the U.S. dogwood occurring outside the U.S.

DiseaseDisease

American chestnutAmerican chestnut trees were once 1/4th of all trees in the trees were once 1/4th of all trees in the Appalachian Mountains. Infection by a fungal blight Appalachian Mountains. Infection by a fungal blight destroyed all chestnuts of reproductive sizedestroyed all chestnuts of reproductive size.

Introduced SpeciesIntroduced Species

The fungus that destroys The fungus that destroys the American chestnut was the American chestnut was introduced with a introduced with a shipment of nursery stock shipment of nursery stock from China in 1904, so it from China in 1904, so it was in actuality an was in actuality an introduced exotic introduced exotic speciesspecies..

Introduced SpeciesIntroduced Species