5-5

Biology 5-5 Reading Notes:

Conservation Biology=relatively new discipline of biology that studies all aspects of biodiversity w/the goal of conserving natural resources for this generation and future generations. It’s unique bc it’s concerned w/development of scientific concepts and the application of these concepts to the everyday world. A main goal is to manage biodiversity for sustainable human use.

Conservation biology supports the following ethical principles:

Biodiversity is desirable for the biosphere and humans
Extinctions from human acts are undesirable
Complex interactions in ecosystems support biodiversity so it’s desirable
Biodiversity brought by evolutionary change have value, no matter it’s practical benefit

It’s estimated that in the next 20-50 years, 10-20% of species will be extinct if we don’t take action

bioinformatics=the science of collecting and analyzing biological info

Molecular, descriptive, and biogeographical info is being collected to eventually protect biodiversity

biodiversity=the variety of life on Earth

It’s estimated that there’s 10-50 species and that 1,200 of them in the U.S. and 30,000 globally are in danger of extinction

Endangered species=in peril of immediate extinction through most/all of its range (ex: black lace cactus, armored snail, hawksbill sea turtle, california condor, west indian manatee, and snow leopard)

Threatened species=organisms that likely will become an endangered species in the future (ex: navajo sedge, puritan tiger beetle, gopher tortoise, bald eagle, gray wolf, and louisiana black bear)

Biodiversity is described as an attribute of 3 other levels of biological organization: genetic diversity, community diversity, and landscape diversity

Genetic diversity=variations amount members of a population. If a population has high genetic diversity, more members will survive a change in the ecosystem (ex: 1846 blight in ireland, 1922 wheat failure in the soviet union, and 1984 outbreak of citrus canker in florida)

Community diversity=is dependent on the interactions of species at a certain locale. It increases biodiversity in the biosphere. Some saved charismatic species like the condor, ferret, or owl but this isn’t as effective. Best approach is to conserve species that play a critical role in the ecosystem. Saving a community can save many species and same goes for the opposite (ex: opossum shrimp were introduced into Flathead Lake in Montana and it was food for salmon but this resulted in less food for fish, bald eagles, and grizzly bears)

Landscape diversity=involves a group of interacting ecosystems. Within 1 landscape, there might be plains, mountains, rivers, and they may be connected only by remnants (patches) or strips of land that allow organisms to move 1 place to another. Fragmentation reduces reproductive capacity and food availability, disrupting seasonal behaviors.

Biodiversity isn’t evenly distributed through the biosphere. It’s highest at tropics and lowers towards land, fresh water, and oceans.

Biodiversity hotspots=contain unusually large concentrations of species. They contain 44% of higher plant species and 35% of terrestrial vertebrate species but only cover half of 1.4% of the Earth’s land area (ex: madagascar, cape region of south america, indonesia, coast of cali, and great barrier reef of australia)

Rain forest canopies and deep-sea benthos have more species than originally thought. These 2 places are often called “biodiversity frontiers”

5 main causes of extinction: disease, habitat loss, exotic species, pollution, overexploitation

Habitat loss=85% of extinction cause cases, exotic species =50%, pollution=24% overexploitation=17%, and disease=3% (add to over 100% bc some have multiple reasons for extinction)

Macaws have various reasons for species decline including habitat loss,being hunted for food and pet trade

Habitat loss is rly concerning especially in tropical rainforests and coral reefs bc they’re rich in species. Tropical soils contain limited nutrients, but when trees are burned, nutrients are released that support a lush growth for the grazing of cattle for abt 3 years.

Habitat loss affects freshwater and marine biodiversity too mainly bc a lot of ppl live near the coast. 60% of coral reefs have been destroyed/verge of destruction and they may be gone within the next 40 years. Indonesia lost 45% of its mangroves (mangrove destruction is rly bad too). Wetlands, estuaries, and seagrass beds are also being destroyed by humans

Coral reefs=areas of biological abundance found in shallow, warm tropical water beneath the surface of the water. Usually occur in the Caribbean and southern hemisphere continents. Largest one is the Great Barrier Reef. Stony corals (animals as small as polyps w/a carbonate exterior) are chief constituents of coral reefs

Coral reefs can be called “rainforests of the sea”

Coral reef degradation can be caused by overfishing, tourist divers, boat anchors and propellers, oil spills, pollution, climate change, and coral disease increase. Abt 58% of coral reefs are being harmed by humans

1 of the most harmful methods of collecting fish is cyanide fishing (cyanide’ a poison that shuts down cellular respiration by interfering w/mitochondrial electron transport chain)

The US imports a lot of marine organisms. Abt ⅔ is from philippines and indonesia (where cyanide fishing started and then spreads from)

Exotic species=non-native members of an ecosystem

Humans have introduced exotic species in new ecosystems from: colonization (like pilgrims bringing dandelions for salads or pigs as animals), horticulture and agriculture (like Kudzu, thought to be helpful, being brought to US and covering many trees/plants or hyacinth being brought bc it’s pretty but now it clogs stuff), or accidental transport (marine species being brought with water from the ballast water, zebra mussels from the caspian sea, formosan termite, fire ant, and nutria a type of rodent)

Islands have native species that can’t compete well against exotics. Examples include: Myrtle trees call a halt to normal succession for native plants on volcanic soil, brown tree snake eats eggs nestlings and birds so it reduced # of native birds, black rats on galapagos reduced # of giant tortoises while goats and feral pigs changed vegetation from highland forest to grassland and destroyed cacti, mice and rabbits in australia stressed native marsupials, and mongoose in hawaii control rats and prey on native birds

pollution=any environmental change that adversely affects lives and health of organisms (3rd main cause of extinction) disease is 5th main cause

Harmful environmental pollution: acid deposition (sulfur dioxide and nitrogen oxides emit in 1 locale but deposition happens across national boundaries and the deposition causes trees to weaken, makes them more prone to disease, and kills small invertebrates and insects), eutrophication (over enrichment, as algae die and are broken down oxygen is used and the decrease in oxygen leads to massive fish kill), ozone depletion (the ozone absorbs most of harmful UV, but chlorine atoms often deplete the ozone layer and the immune system of organisms weakens), organic chemicals (nonylphenols are organic chemicals that mimic hormones and harm wildlife and their ability to adapt to dif. Environments, 20-30% of salmon couldn’t adapt to salt water), global warming (greenhouse gasses allow solar radiation to pass through and make temperatures rise)

Global warming=increase in average temperature in 20th century

Polar region temps warm and then sea levels rise bc glaciers melt and water expands. 1 m rise in sea level could inundate 25-50% of US coastal wetlands
Tropics are affected by global warming bc coral reefs depend on algae living in their walls and algae can’t handle high temps, so the reefs don’t reproduce/grow

Overexploitation=occurs when the #s of individuals taken from a wild population is so great that the population reduces severely (smaller pop’s members are more valuable)

International value of trading wildlife is $20 billion and $8 billion of which is illegal sale of rare species

Rare cactuses sell up to $15,000 each. 1 Siberian tiger sells for over $500,000. Bengal tiger fur sells for up to $100,000

We’ve exploited 11 of 15 major oceanic fishing areas

Persienne fishing=large net surrounds school of fish and the net is closed

Trawling=nets drag onto sea floors to get bottom-dwelling fish

Marine ecosystems can be ruined by overfishing. Ex: orcas ate sea otters bc their preferred fish weren’t plentiful bc of overfishing. Sea urchin population decimated bc there are fewer sea otters to keep that population under control

In Madagascar 93% of primate species, 99% of frog species and 80% of the plant species are endemic (native) to Madagascar

Keystone species=species that influence the viability of a community. They can lead to other extinctions and a loss of biodiversity (ex: bats bc they pollinators and when they die, trees can’t reproduce. Grizzly bears bc they eat young prey keeping populations under control and they’re movers of soil. Other examples include beavers in wetlands, bison in grasslands, alligators in swamps, and elephants in forests and grasslands)

Flagship species=species that evoke emotional response from humans bc they’re cute. This can motivate the public to preserve biodiversity. Ex: lions, tigers, dolphins, and giant pandas.

metapopulation=a population that subdivided into several small isolated pops bc of habitat fragmentation (ex: used to be a lot of grizzlies in Canada but ppl killed them and now they have 6 dif subpopulations w/abt 1,000 individuals)

Source population=one that lives in a favorable area and its birth rate is likely bigger than its death rate

Sink population=one whose environment isn’t as favorable and birth rates equal death rates at best

It’s necessary to save diverse ecosystems at least connected by corridors bc it wouldn't be sufficient to save 1 only. Land protection for 1 species often helps other wildlife sharing the same space

Edge effect=an edge reduces the amount of habitat typical of an ecosystem bc the edges have a little bit of a dif habitat than the interior. Edge effect can be detrimental to some wildlife bc of fragmentation. Ex: Cowbirds are a parasite of songbirds and they feed in edges usually so they are benefited while songbirds have a disadvantage from the edge effect

Gap analysis=used to find gaps in preservation (places where biodiversity is high outside of preserved areas)

Population viability analysis=can help researchers determine how much habitat a species needs to maintain itself (should protect them from extinction and for them to be able to breed/reproduce enough). Ex: Mark Shaffer predicted that grizzlies should have a pop of 70-90 bears but Fred Allendrof said it should be more bc only some dominant males breed.

Dispersal among subpopulations is needed to prevent interbreeding and extinction

Restoration ecology=new subdiscipline of conservation biology that seeks ways to return ecosystems to their og state

3 principles of restoration ecology: 1)best to start as soon as possible so fragments of og habitat aren’t lost 2)best to use biological techniques that mimic natural processes once the habitat’s history is understood 3)sustainable development, ecosystems can maintain itself while giving service to humans

In the Everglades ecosystem during wet seasons, animals disperse throughout the region, but during dry seasons they go wherever they can find water. Settlers began draining the land and at a certain point only when it was convenient for them and not based on wet/dry season. This caused the everglades to start dying, as bird populations are declining from millions to thousands.

The restoration plan for the everglades consists of redesigning the C&SF so that they receive more natural water flow from Lake Okeechobee and only crops that can survive these conditions will be planted. This may help prevent residency development and also there'll be an extended buffer zone that’ll contain reservoirs and water treatment areas etc.