Exam 3 Biology
Terms in this set (46)
What caused the Aral Sea to be depleted of water? What were the ancillary costs?
Dust storms, cancer, loss of biodiversity, jobs, and ecological destruction
Dropped because onset of water diversion in 1960 for cotton farming.
Put 60,000 people out of work. 0 fish catches by 1980.
Salinity increased 14%, river input 92 ppt.
Vegetation reduced 40%. 15 million acres of farmland destroyed.
10 dust storms/ year. 40-90% salt. 43 mil tons of salt blown away.
Cotton: uses furrow irrigation, requires immense labor, subject to disease and insects, pesticides used.
Regional governments trying to rejuvenate
What is the "Tragedy of the commons"? Who brought attention to it?
Garret Hardin, 1968
States that (1) unregulated exploitation cases resource depletion (grazing lands, forests, air, water) (2) no one has the incentive to care for a resource (3) everyone takes what he/she can until resource is depleted
What is the definition of "ecological footprint"? How much more of the worlds resources are we using than available?
The environmental impact of a person/ population. Amount of biologically productive land + water. For resources and to dispose/recycle waste.
We've surpassed earth's capacity to support us. 30% more of earth's resources than available on a sustainable basis.
Know 3 major environmental ethics.
Preservation: unspoiled nature should be protected for own inherent value. We should protect our environment in pristine state because promotes human happiness and fulfillment John Muir
Conservation: use natural resources for greatest good for the most people. Utilitarian standard that calls for prudent, efficient, and sustainable resource extraction and use. Gifford Pinchot, first head of US forest service and governor of PA.
Land: Healthy ecological systems depend on protecting all parts. Aldo Leopold believed that Humans should view themselves and the land as members of same community. Obligated to treat the land ethically. Land ethic will help guide decision making.
Natural science: info about natural world
Social science: human interaction/ behavior
3 ethical perspectives
1. anthropocentrism, only humans have rights
2. biocentrism, certain living things also have value
3. ecocentrism, whole ecological systems have value
Know about John Muir, Teddy, and Aldo
John: preservation. Teddy with John
What is environmental justice?
poor and minorities at risk from the activities of those more well off and in power. String of power plants, dumps, pollution hazards, roads, export of trash to 3rd world countries
What does Ruddiman think humans have done to climate? How?
Humans converted so much land to pasture and agricultural purposes that it released tons of CO2 and methane (from animals) that countered the declining trend in those gases. In turn, that resulted in reversal of global cooling 7,000 years ago.
Which biomes/ continents have had the most deforestation
Amazon and Indonesia
Borean, North America, Brazil
What happens to the amazon when it's clearcut? What are the microclimatic changes that occur? How do these affect global weather patterns?
Convective recirculation will decrease, and the amazon could dry out, affecting weather worldwide.
Rising heat flux can affect N. America.
What is the most prevalent way forests are destroyed?
Slash and burn agriculture
Why is deforestation so detrimental on Madagascar? What is so unique here?
More than 80% of species endemic to Madagascar. Home to 100 species of Lemurs, which live no where else.
Which region of the US has experienced the most deforestation?
What is no till agriculture? Why beneficial?
Growing crops without disturbing the soil. Increases amount of water that infiltrates into soil and increases organic matter retention and cycling of nutrients.
Rates of erosion get so small that soil formation can't make up for those losses. In other words, agriculture could become sustainable
Why is improper irrigation so detrimental to farming? What can it cause, especially in dry areas if done properly?
Salt in soils. 30% of agriculture suffers from salt buildup.
What are several theories as to why climate change causes human conflict?
Wars increase when climate cools.
What are the ranges in estimates of global species diversity?
4-30 million. Up to 100 million
where are most species located
what are 5 major kingdoms of life
monerana, Protista, fungi, plants, animals.
What are three domains of life? what are we more closely related to?
bacteria, archea, and eukaryotes
Name at least one factor that distinguishes one kingdom from another. What is at least one characteristic of plants, but not animals? Of protists? Fungi? Bacteria?
Eubacteria and archea. All single sell species. Prokaryotic-no internal organelles.
Animals are multicellular, no cell walls, heterotrophs, store food as glycogen.
Protists are a grab-bag kingdom of mostly unicellular organisms.
Fungi have cell walls of chitin, multicellular, extracellular digestion, more similar to animals.
Plants have cellulose cell walls.
Know what factors unit all of life
all life carbon based
uses DNA and RNA as genetic material
proteins used for all biological reactions and all enzymes are proteins
all life shares common biochemical pathway
Eukaryotes from prokaryotes
what is the binomial classification system
Caspar Bauhaus, Carl Linneaus
what is the theory of endosymbiosis
DNA circular, naked, no introns
organelles had double membranes, inner one resembled prokaryotic membranes
Prokaryotic cells engulfed/ incorporated into other cell digested.
One theory is that this was a way for some organisms to cope with the ever rising oxygen levels in the atmosphere. oxygen can be toxic to some organisms. those that exist without oxygen are anaerobes. Require it are aerobes.
What is the global pattern of species diversity with regard to latitude? Why?
Tends to decrease with latitude. More species in tropics, fewer in colder, temperate areas.
What were some of the major extinction events?Their causes? What about present period?
Astroid, volcanic eruptions, Siberian traps
What is an ecological community?
composed of populations of interacting species.
What are the various ways that species can interact in a community?
Mutualism, commensalism, competition, preation, parasitism, herbivory
What is an ecological niche? 2 scientists developed this concept.
Set of all factors necessary for the growth and survival of a species. Includes habitat, growth characteristics, food sources and shelter.
Evelyn Hutchison. Fundamental (exists in time and space). Realized (exists when interacting with other species)
Fundamental vs. realized
realized: balanus, chthamalus
What is ecological secession? Primary v. secondary? Catherine Keever and what did she study?
Orderly change in species and ecosystem functioning with time.
Primary: development of plant and animal communities after moderate to severe disturbance, such as storms or fires, where plants and animals are not completely eliminated.
CK showed very specific patters of secondary succession from old fields back to forest. After the broom sedge phase, tree seedlings would invade.
How did Henry Gleason and Frederick Clements differ with regard to their conception of communities?
Clements: ecosystems progressed to "climax", community may be thought as "super-organism"
Gleason: thought species segregated individually according to their own niche requirements and so communities were the result of numerous individual interactions of species, not those from an evolutionary derived community
Understand how Michael Mann constructed his hockey stick graph showing temperature increases due to human activities-the idea of ecological and climate proxies. Name some proxies used
graph looks like a hockey stick
Proxy: preserved physical characteristics of the past that stand in for direct measurements-allows scientists to reconstruct past conditions before records were kept.
examples: ice cores, tree rings, fossilized pollen, corals, lake and ocean sediments, cave formations, pack rat middens
Know that cyclic process such as solar radiation output and sunspots, and el nino activities cannot give rise to increasing warming trends and thus the warming we see today must be do to other causes
causes mostly manmade
What is an el nino event? How does it affect weather globally? This year was one of the strongest el ninos, but kept jet stream northward for most of the winter, which is why snowfall amounts were low.
Western winds subside, and warm surface waters move close to south america. cases more thunderstorms and changes global wind patterns
where is most of the heat that is retained by greenhouse gases ending up
why does the uncertainty in the hockey stick graph get reduced around 1500 and even more in recent times
what is a tree ring? how are they used to determine past climates?
the barcodes of trees, width/color
How can ice cores be used to reconstruct past climates? Know that one can get info on greenhouse gases from trapped bubbles, and temp data from stable isotope analysis.
See how they were formed. tells a lot about prehistorical atmospheric chemistry and air temperatures
correspond to yearly depositions of snow
obtained by thickness of annual ice layers
what is an isotope? what distinguishes one from another? 4C isotopes and how 13Cand 14C can be used to determine ages of collected material.
Atoms with same number of protons but different numbers of neutrons
C11, 12, 13, 14
C14 dates Egyptian mummies, icemen, Turin
How can oxygen isotopes be used to determine past weather?Know this in general terms-what types of isotopes diffuse faster, and evaporate more easily and which tend to fall out of rain more easily.
More O18 in colder precipitation than warm. Content of O18 in ice.
O18/O16- high ratio= cold climate
Lighter isotopes evaporate faster. More O16 water enters atmosphere.
How far back can we reconstruct past climates?
What is albedo and how do changes in albedo affect global warming? When ice melts in the arctic, what happens to the albedo?
Reflected radiation from a surface to the total amount of radiation striking that surface.
As ice melts, albedo goes down. Low albedo results in global warming because more radiation absorbed by oceans/land, more re-radiated.
What causes sea levels to rise with global warming? Why is Rush Limbaugh climatically illiterate
claimed media made up polar vortex to bolster global warming. polar vortex affects just 2% of earth's surface.
What causes ocean acidification? Why is this bad for certain organisms?
CO2 mixes with sea water. Affect corals, crabs, shrimp, and many other organisms, especially those that make shells, as when pH becomes more acidic, dissolves shells.
What is a "wedge" strategy? How does it work?
Reduces carbon emissions that grow in 50 years from 0-1 GtC.year. The strategy has already been commercialized at scale.
Redirects flow of 25 giga tons of C. in first 50 years. 2.5 trillion dollars at $100/tC. a viable solution to CO2 problem should provide at least 1 wedge
Know various conservation and alternative energy ideas to combat climate change
carbon capture & storage (CCS)
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