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383 Cards in this Set
- Front
- Back
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Ecology
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The study of the interaction between the biotic and abiotic world
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biotic
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living
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abiotic
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physical/nonliving
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give an example of an ecological interaction
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the coral reef: living organisms can affect physical environment and physical environemnt can also change organsims
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give an example of coral reef interaction
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hydra make a stonelike stxr to live on (so creating a physical environment)
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hydra --> stone strxr-->? -->?
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coral --> fish habitat
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environmentalist
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person with a philosophical/moral concern for protecting the natural environment NO SCI TRAINING
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example of an environmentalist
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Al Gore and Greenpeace
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environmental scientist
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SCIENTIST from a variety of disciplines not solely biology (chem, enginer, comp sci); applied science focusing on effects environment had upon humsn; TEAM approach so pull people from different fields to collaborate
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example of an environmental scientist duties
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take and analyze water samples
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ecologist
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BIOLOGIST concerned with organisms, studies the way organisms, populations, communities and ecosystems work
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ecology is the branch…..
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of biology that focuses on interaction between organisms and their environment
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what abiotic factors affect organisms?
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temperature changes, rainfall fluctuations, chemistry of soil and air
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give an example of how organisms respond to temperature
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shedding or growing fur, sweating/panting, trees drop leaves
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give an example of how organisms respond to rainfall fluctuation
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trees grow roots shallow or deep depending on water source; animals burrow to reach water; migrate
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give an example of how organisms respond to chemistry of soil and air
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change root uptake of needed minerals; migrate; prep/secrete buffers to prevent/slow change in acidity; open/close stomata
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how do organisms affect abiotic components of their environment?
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oxygen revolution; soil formation
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what is to oxygen revolution?
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living organisms add oxygen to Earth's atmosphere
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what are some effects of the oxygen revolution?
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aerobic respiration (mitochondrial production of ATP and energy), ozone layer formation in stratosphere
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what is the importance of having an ozone layer?
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protects from carcinogenic UV radiation such that organisms can get onto land
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how is soil formed?
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death and decay of living organisms adds to the organic portion of soil; living organisms create soil stxr and texture through phys/chem processing of soil
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what is the central question of Ecology?
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What factors influence the distribution and abundanc of species on Earth?
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Ecology levels mneumonic
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Old Sappy People Catch Easy Breaks
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organism
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individual life form
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species
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group capable of INTERBREEDING, don't normally breed with other groups
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population
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members of same species living in same area region SHARE GENE POOL of genetic variation
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community
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all population in an area at a time Ex: Bedford community has a black/tongan/mexican/white populations, they interact
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why would you want a diverse community?
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greater diversity = more complex interactions and therefore a more stable commuity because resilient to disturbance; removing a species isn't devastating because other options are available
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ecosystem
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dynamic entity of community and abiotic environment; composition is determined by factors such as nutrients, temp, pop. Density
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give an example of changing factors to change an ecosystem
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a fire would change the stxr of a forest
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biosphere
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the GLOBAL ecosystem; EARTH, the part of Earth and its atmosphere in which living organisms exist or that's capable of supporting life
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What are 3 major themes of ecology?
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Energy flows one direction and all organisms require energy;
organisms have limited energy resources so must allocate energy for growth, maintenance and reproduction; mineral elements cycle (finite number of atoms) |
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what is organismal ecology focused on?
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why/how animals live and survive where they do; anatomy, physiology, behavioral ways organisms meet abiotic challenges of environment and are successful; evolutionary fitness and adaptions
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what is success?
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survive and reproduce
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evolutionary fitness?
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probability of surviving and reproducing
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how deep can the sperm whale dive?
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3 km (9800 feet) for 1 hour +
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why are we concerned with the sperm whale?
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its depth and length of dives while maintaining enough oxygen may have implications for how we humans can survive underwater
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how has the kangeroo rat adapted to its desert habitat?
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22 species live mostly in California and never drink water;
eat dry seeds and form water during the digestion of seeds, no sweat/pant, kidneys remove nitrogen without water, also burrow |
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the urine of the kangaroo rat is ____X more concentrated than blood
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17
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what do population ecologists look at?
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number of individuals and why number varies in time and space, genetic stxr of the population, breeding, migration
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describe situation of cheetahs in Africa
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during Pleistocene Age only one species survived so inbreeding has occurred (share 99% similarity)
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what are the implications of the genetic situation of cheetahs?
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low survival, poor sperm quality, disease susceptibility b/c can’t adapt to changes
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community approach (Ecological)
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interaction of species (competition, predation, mutualism); stxr change over time (simple-->complex); what factors control biodiversity?
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“old growth” forest
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in Pacific NW, on federal land, never been logged/touched, no strong human influence
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spotted owl
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endangered species 1990 so saved old growth forests b/c made living here
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ecosystem ecology
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ecosystem defined by scientist, how does abiotic (energy flow, elements) effect species living there?
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Hubbard Brook Ecosystem Study
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in White Mtn. Natl. Forest, NH, 1955, outdoor laboratory for studies, cleared forests in patches or such at different intervals, comparison of different element levels
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biosphere ecology
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need satellites and computers, todays tech, global cycle of energy, elements, water, air relate to changes in populations, composition, production
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ozone hole
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atop Antarctica, Oct 3, 1999 because chemicals that we have put into the air last, ozone depleted areas is floating out
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what are the roles organisms play in ecosystem in terms of?
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energy flow and element cycling
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heterotroph
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energy derived from eating other organisms such that cannot get energy unless it’s already in organic form CONSUMER
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heterotroph examples
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animals, fungi, animal like protista bacteria
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autotroph
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obtain energy from organic food they make from simple inorganic materials via photosynthesis or chemosynthesis PRODUCER
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autotroph examples
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plants, plantlike protista, cyanobacterium
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what are the 3 roles in element cycling?
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producer, consumer, decomposer
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with elements, what does a producer do?
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get elements inorganic form and convert to organic compounds (simple sugars)
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with elements, decomposers...
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breakdown biomass of all living things and RETURN element to ecosystem
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give examples of producer, consumer and decomposer...
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producer: tree, cosumer: giraffe, fungi: decomposer
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saphrophytic
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get energy form dead or decaying by secreting enzymes outside body then absorb
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what is in wood that humans cannot digest?
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lignin and cellulose but saphrophytes have enzymes that can
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example of parasitic fungi
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eating ant
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example of pathogenic fungi
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smut disease, pollinators and wind carry the spores
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example of predator fungi
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trapping nematodes
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example of Protista
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phytoplankton, aquatic producers (float in water--diatoms) and form colonies (Red tides = algal blooms)
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example of where Bacteria live?
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all places on Earth: hot acid baths/ppols, highly radiated environments, on humans
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niche
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functional role of an organism in an ecosystem; NOT PHYSICAL SETTING
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habitat
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physical setting
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what's the difference between a niche and a habitat?
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habitat is physical setting, niche is what the organisms eats, how it makes nest, active period of day, tolerable climate, etc.
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T/F No 2 species can have EXACT same niche
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true; competition would ensue and one would inevitably beat the other
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Anolis lizards
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4 different species living in same tree but occupy different niches
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Anolis insolitis lives…
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twigs
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Anolis cybotes lives
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lower portion of trunk
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Anolis chlorocyanus lives
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top portion of trunk
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Anolis garmani lives
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tree tops
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3 experimental setting used by ecologists
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natural ecosystems, semi-natural microcosms, controlled settings (all experiments must eventually be tested in nature)
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semi-natural microcosms
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mimic the natural environment
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example of controlled settings
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greenhouse, lab, growth chamber
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T/F Tools for ecologists come in a kit
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false; a variety of often "built" tools are employed molecular, mathematical, imaging ex: satellite collar to track caribou
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what are some common molecular tools?
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DNA fingerprinting, PCR techniques, Molecular markers
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natural field study example
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tree caged to exclued birds to determine if insect damage increases w/o birds
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microcosm example
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artificial ponds created such that experimenter directly controls composition
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laboratory study example
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houseflies reared together/apart to look at competiion
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U.S. LTER
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long term ecological research establish 1980 by the NSF with 26 sites (Europe also has one)
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NEON
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National Ecological Observatory Network, new 30 year study of the North Amer continent; connected study of 20 sites
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what is our support system?
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clean water, oxygen
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how can we get resources for growing human population without destroying global biosphere?
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sustain complex ecosystems ex: giant kelp forest of Pacific coast and otters
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1972 Marine Mammal Act
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conservation of marine mammals; otter population rebounds in 90s but now Calif fishermen complain about decreased amounts of shellfish
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early earth atmosphere
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methane, ammonia, hydrogen sulfide
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current earth atmosphere
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Nitrogen (78%), Oxygen (21%), Argon, CO2, Water vapor
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Somalia malnutrition and nitrogen
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lack of protein = low nitrogen, cannot use nitrogen in the air because it's not fixed already
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3 levels of the atmosphere
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troposphere, stratosphere and mesosphere
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troposphere
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11 miles above surface, holds 75% of atmospheric gases (gravity); THINNING
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stratosphere
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11-30 miles above surface, AIRPLANES, ozone layer
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ozone layer
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oxygen + UV = O3
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what does ozone layer do?
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reduce amount of UV reaching earth's surface
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role of CFC in ozone
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chlorofluorocarbons found in propellants and refridgerators causing holes in the atmosphere especially around the South Pole
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mesosphere
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30-60 miles above surface, low temperature, sparse elements
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1987 Montreal Accord
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international law phasing out substances that damage the ozone layer expect recovery by 2050
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why is ozone in the troposphere now?
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internal combustion engines and motor vehicles (ex: Smog atop Los Angeles)
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what is the primary source of energy for the biosphere?
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energy from the sun LIGHT
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What is the solar constant
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energy averaged across all area and days 1400 W/m2
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solar constant
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amount of solar electromagnetic radiation per unit area that’d be incident on a plane perpindicular to the rays at 1 AU
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1 AU
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halfway between Sun and Earth
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UV Wavelength
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<400 nm
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visible wavelength
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400-700 nm (400 = violet and 700 =red)
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infrared wavelength
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700nm
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absorption spectra
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absorb energy from radiating field shows absorbed wavelength
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_____ absorb red and violet
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chlorophyll reflects blue and green
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_____ absorb all others and reflect red and orange (large wavelengths)
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carotenoids
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water absorbs_____ and reflects_____
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red and IR, blue is reflected
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birds and insects detect light in the ? range
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UV range
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animals that are nocturnal or live in dark habitats us ____ senses
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IR ex: snakes use pit organs to sense their prey
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what does a bee see in a sunflower?
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UV images such that patterns arise on the petal and tell where to find food(nectar)
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explain visible and IR light and the greenhouse effect
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atmosphere allows visible light in which warms the Earth’s surface during the day. At night, the surface emits IR radiation that travels back into space to cool the Earth. The CO2 traps IR at the surfaces causing an overall warming trend because not all IR able to escape so Earth stays somewhat warm at night
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what causes global warming?
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increased use of fossil fuels (coal, oil, gas) because increases the amount of CO2 added
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what are the major greenhouse gases?
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CO2 (67%) CH4(18%) Nitrous Oxide (N20) (5.9%) CFC-12(5.5%) CFC-11(2%)
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are changes in CO2 concentration new?
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no; there have been past fluctuations looking at Ice Ages and interglacial warming; saw a spike around Industrial reevolution
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what happened at the industrial revolution, 1800?
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CO2 levels rise from 280ppm to 400ppm
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what is the projected [CO2] at 2035?
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550ppm with a 5% increase each following year
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what stabilization level is the Intergovernmental panel on climate change pressing for?
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450ppm stabilization; 350ppm is the other proposed “safe” level
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What is a C sink?
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plants absorb CO2 and store C in their biomass as carb
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how has global warming increased CO2 uptake?
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plants can now grow in places previously too cold to sustain growth
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FACE-DUKE
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placed CO2 emitting towers to create high [CO2] to look at plant response to heightened levels and gain insight as to what is to come
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what are C sources?
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bacteria as release CO2 from decomposition; Carbon-storage tundra permafrost is melting and turning to soil releasing CH4 and CO2; aerosols
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what is an aerosol?
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tiny particle suspended in air from both natural and human activity
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ex of natural aerosl
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salt, sand, volcanos, rain/clouds
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ex of man made aerosol
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smog soot
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albedo
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reflective ability seen at snow caps and clouds because of light color
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what is risk to sea because of global warming?
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raise sea levels and possibly destroy island nations
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what are the two most important sheets?
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West Antarctic Ice Sheet and Greenland Ice Sheet
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If the west Antarctic ice sheet were to melt, How high could it raise see levels?
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by up to 20 ft. this is especially troubling because it has many cracks and is unstable
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how large is the greenland ice sheet and how high could it raise sea levels?
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1 million sq miles, 23 ft
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how hight do scientists predict sea levels wll rise by 2010?
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by 2-3 ft
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how does salinity and temperature affect ocean currents?
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causes them to flow and distribute water around the globe (Global Temperature Modulation System)
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what is the Thermohaline current?
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large scale ocean circulation driven by density gradients in the ocean
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does cold, salty water rise or sink?
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cold, salty water sinks causing warm less salty water to flow into the region; ocean currents are created that modulate global temperature and mix oceans
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what are 4 ways that rising sea levels can impact life?
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habitats change
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what is a range shift?
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organisms move and migrate or they become extinct because of encountering new competition, pathogens and predators
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desertification?
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already dry areas will get drier (i.e. Texas)
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what to those who say that set aside refuges and reserves will protect animals?
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these may not be enough or in the correct location to protect endangered species
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where are the strongest changes due to ice melting and rising sea levels occurring?
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polar regions
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trophic mismatch
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a subtle effect of climate changes in that the organisms are not in the right place at the right time to get food
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give an example of trophic mismatch
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caribou (wild reindeer); typically travel to the coast to give birth at the same period that plants are in peak bloom period so that there are enough available nutrients to sustain mothers and calves will grow quickly; however, warmer temperatures have flowers blooming earlier (4C) so that when caribous arrive, the plant growth cycle is beyond peak productivity and nutrition
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How would drilling for oil on the coast of Alaska affect the caribou?
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negatively because this is where they travel to give birth
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Why did placing polar bears on the endangered species list cause political uproar?
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in May 2008, this occurred; Bush had not wanted to admit that human activities were negatively affecting the environment
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describe the effect of global warming on disease
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increased growth of pathogens and vectors, developing regions impacted the most, food insecurity, vecotr-borne disease, high impact in areas prone to drought/desert
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why would developing nations bare the brunt of global warming?
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because have less resources to combat and treat disease
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what are some diseases that could increase because of global warming?
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malaria (mosquito), onchocerciasis (river blindness; black fly) dengue (mosquito) and schistosomiasis
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what is the effect of global warming on the freq and severity of storms?
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el nino, la nina
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el nino causes...
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El Nino Southern Oscillation (ENSO); equatorial Pacific warmer than normal and pushes colder nutrients awya such that fisherman noticed a decrease in fish
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in the absence of el nino describe the nutrient flow
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cold current up the coast of Peru Ecuador and Chile from the South Pole carrying nutrients such as sulfur, calcium and phosphorus to support algae ->small fish_-->large fish
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what is La Nina?
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waters are cooler than average (typically follows an El Nino year with each period lasting approximately 1-2 years
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overall what are some effects of el nino?
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felt strongest in the tropics , lack of monsoons, drier conditions lead to food instability, moderate effects in temperate zone
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when was the most extreme el nino?
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97-98
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how el nino affect mexico/central amer? and australia?
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drought; fires sent smoke to U.S.; drought severe water shortages
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how el nino affect midwest and southwest?
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drought
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how el nino affect west coast?
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severe coastal storms; heavy rain, flood and mudslides
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how el nino affect east coast?
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mild winters
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how does el nino and la nina affect phytoplankton?
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el nino; low phytoplankton growth; la nina: hugh blooms of phytoplankton
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describe link between climate and conflict
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as resource scarcity; tensions increase
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radiation
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return energy received from the sun
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conduction
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touch
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convection
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via moving air and water (like convection oven)
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evaporation
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heat loss with water evaporation from organism’s surface
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transpirational
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plants open stomata and water evaps out of holes in leaves
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most organisms req water in what phase?
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liquid (0-100C)
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how does freezing affect enzymes and membranes?
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enzyme are inhibited and membranes are disrupted
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what is the typical upper limit for organisms in terms of temperature?
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45C (113F) or less
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what temperature can cyanobacteria survive up to?
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75C (167F)
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what temperature can archaebacteria survive up to?
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110C (230F)
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what are three effects of high temperatures?
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denature proteins, accelerate chem processes (enzyme), affect properties of lipids (lipid membranes)
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how do organisms live?
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adaptations!
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homeotherms
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thermoregulate to keep internal temperature high; demands high energy (fat storage) ex: humans; many animals hibernate after bldg fat stores to keep energy req low nd last longer
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poikliotherms
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have wide tolerance and individuals can acclimate by changing lipids in cell membrane; cell membranes flexibility influences the activity of membrane proteins
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heat shock proteins
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proteins whose expression increases when organism is exposed to elevated temperatures or stress; acts as a membrane chaperone to facilitate stabilization and folding of proteins
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cold shock proteins
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proteins whose expression increases when organism is subjected to suboptimal temperature levels; protects cell components from change
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how do fish beneath ice regulate temperature?
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antifreeze of glycerol or glycoproteins circulating in bloodstream which lowers the freezing point
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where is Earth’s abundance of water located?
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primarily in the oceans
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water is an excellent ? and ? for chemical processes
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solvent and medium
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does water have good thermal qualities?
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yes it conducts heat rapidly; resists temp changes; is less dense when frozen (ice floats)
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what minerals are found in saltwater?
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sodium, chloride, magnesium and sulfate
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does cold or warm water have more nutrients?
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cold water
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what minerals are found in freshwater?
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Calcium and HCO3 and sulfur
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where does the Calcium found in fresh water come from?
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limestone (easily weathered rock rich in CaCO3
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what does the mineral content of water depend on?
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the kind of bedrock in the area
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areas rich in limestone leads to hard or soft water?
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hard because limestone is a soft rock such that lots of ions (Ca2+ and HCO3-) get into the water
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what bedrock leads to soft water?
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granite
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what are the two most essential elements?
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Nitrogen and phosphorus; needed in protein, DNA and ATP
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what is a result of low concentration of essential elements?
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population growth is limited in the natural ecosystem
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in freshwater, what are the concentrations of nitrogen and phosphorus?
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N [0.4mg/L]>P [0.01mg/L]; therefore adding Phosphorus would increase productivity
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in saltwater, what are the concentrations of nitrogen and phosphorus?
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N [0.01mg/L] <P [0.01-1mg/L]; so adding Nitrogen would increase growth
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overall which has more resources, freshwater or saltwater?
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the ocean is more limited in resources
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Why does the ocean hold 50X more CO2 than the atmosphere?
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1. Chemical pump; 2. Physical Pump; 3. Biological Pump
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Chemical pump
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bicarbonate-->CO2-->dissolved; so as CO2 dissolves, the reaction is pulled in the forward direction and more CO2 able to be dissolved
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physical pump
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CO2 is moved to deep ocean at the poles, because ocean currents get colder, pick up CO2 and cold water shrinks
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biological pump
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CO2 is moved to deep ocean as organisms which make carbonate shells and organic matter sink to ocean floor when they die; the CO2 is fixed into organic compounds; bacterial decomposition releases the CO2 again
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describe ocean acidification
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increased CO2-->increases carbonic acid-->lowers the pH
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Since 1800, what has been the average pH decrease?
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0.1
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what is the expected pH decrease by 2100?
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0.3-0.7
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What are the effects of ocean acidification on shell producing organisms and fish?
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inhibits corals, echinoderms and mollusks shell formation; lowers the pH of fish body fluid, disrupts food sources, mixes nutrients and modulates temperature
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echinoderm?
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starfish, sea urchin “echino=spiny”
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what is ocean upswelling?
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cold water carries nutrients to the surface because of spinning of the Earth and water currents below, replaces warm nutrient-deficient waters and leads to greater overall productivity
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what causes upswelling?
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"winds and ocean currents; winds blow across taking surface water with it and leave a ""hole,"" upswelling from waters below occurs to fill the hole"
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coastal upswelling
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along edges of continents, leads to phytoplankton and algae growth and therefore fish growth as well; a lot of water washes down river to the sea
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equatorial upswelling
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occurs along the North and South boundary of the Equator; rotation of Earth is slowest at the Equator
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Coriolis Force
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because air is blowing across surface, however the Earth is spinning such that the currents are diverted North and South
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what is the pH of natural rain?
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5.6
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what causes natural rain to be slightly acidic?
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CO2 in the air and natural acids in the atmosphere
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what is the pH of Acid rain?
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anything below pH=5
|
|
|
what is acid rain formed from?
|
nitrates->nitric acid and sulfates->sulfuric acid
|
|
|
what is the pH of surface water
|
Jun 9, 2011
|
|
|
what is the standard for acidic surface water?
|
pH=4 or less
|
|
|
what is DC surface water pH?
|
3.5/3.8 - 4.5/4.7 (averages about 4.2
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|
episodic acidification
|
amount of acid is not steady throughout the year because precipitation does not fall year rond
|
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|
what is the effect of human pollution on episodic acidification?
|
causes episodes of greater magnitude and longer duration
|
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|
what does acidification occur with?
|
high stream flows because of heavy rain storms and snow melting
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|
|
why does snow melting cause acidification?
|
snow accumulates acid on the surface, so during the spring we get a high pulse
|
|
|
what is a big elemental problem with acid rain?
|
aluminum mobilization
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|
|
describe the process of aluminum mobilization?
|
Al is naturally very low in freshwater because its not soluble and pH=7 (stays in soil); lower pH increases solubility; enters soil, water and streams; plants absorb and toxic (to land and aquatic)
|
|
|
describe another effect of acidification?
|
base cation depletion
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|
|
base cation depletion
|
Ca is abundant in soil and freshwater b/c of rock weathering, the Ca base cation neutralizes acidity in soil because of cation exchange; if ratio of acidification exceeds rate of Ca2+ addition by rock weathering, the buffering ability of Ca2+ can be overwhelms
|
|
|
what areas are at risk of acidification?
|
soil with base cation saturation of less than 20% have a low buffering capacity, surface waters can be acidified by inputs of sulfur and nitric acids
|
|
|
how do high altitudes compare in sensitivity to acid rain?
|
most sensitive; greatest amounts of deposition (cloud water); shallow soil with LOW buffering capacity
|
|
|
how do logged forests compare in sensitivity to acid rain?
|
more sensitive b/c deforestation cause depletion of base cations that’d be supplied by natural decomposition
|
|
|
pH of the Smoky Mountains (NC)?
|
2.5-3.5
|
|
|
What are some determinants of soil formation?
|
climate (rainfall/temperature), bedrock, vegetation, animals, microorganisms, topography, time
|
|
|
topography
|
slope of land
|
|
|
from top down, name the layers of soil
|
O dead organic matter, A humus, zone of ion leaching; B low organic/zone of ion accumulation--plant roots; C weathered rock
|
|
|
how long does it take to make 1 inch of soil at best conditions?
|
100 years
|
|
|
depending on availability where are a plant’s roots?
|
superficial or deep depending on water
|
|
|
what makes soil formation slow?
|
dry/arid, cold/acidic, little oxygen
|
|
|
what are the best conditions for soil formation?
|
warm, mesic regions, may develop loam
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|
|
mesic region?
|
contain a moderate amount of moisture
|
|
|
loam
|
fertile soil of clay and sand containing humus
|
|
|
what is the rate of soil decomposition in tropic regions?
|
rapid turnover, so little soil; elements taken up into biomass not stored in soil; not enough soil for agriculture year after year
|
|
|
T/F all soil particles are the same size.
|
false, vary in size, different percentages of particle sizes lead to different properties of soil
|
|
|
clay
|
<0.002mm slow drainage good nutrient holding
|
|
|
silt
|
0.002-0.05mm
|
|
|
sand
|
0.05-2mm fast draining, nutrient leaching
|
|
|
loam soil
|
relatively equal mixture of clay, silt and sand
|
|
|
coarse sand
|
large air spaces such that water drains rapidly; roots obtain oxygen but mineral nutrients are easily leached
|
|
|
finer sand
|
packed tightly, water and nutrients held at roots; WATER LOGGING can occur
|
|
|
water logging
|
saturated with or full of water
|
|
|
soil loss because of ? and ? is a serious global problem
|
erosion and land degradation
|
|
|
poor agricultural practices and deforestation do what to the topsoil?
|
allow topsoil to wash/blow away leaving deserts behind
|
|
|
Haitian city of Gonaives
|
2004 Hurricane Jeanne killed >2000, poorest country of W. Hem., 80% live below absolute poverty, 47% of <5 yr olds have severe or moderate stunting
|
|
|
describe Haiti’s economy, demographics and ecology
|
poor, densely populated (~8 million ppl) and 97% deforested
|
|
|
describe the vicious cycle of top soil erosion and poverty in Haiti
|
w/o roots to bind soil, soil washed away -->mudslides-->less land for use-->more poverty
|
|
|
Has the Middle East always been desertlike?
|
no it was once flush
|
|
|
What has Nepal done to combat topsoil erosion?
|
terraced agriculture; plant legumes which make their own fertilizer with symbiosis
|
|
|
photosynthesis equation
|
carbon dioxide + water > sugar + oxygen (respiration is in the opposite direction)
|
|
|
trophic levels
|
each of several hierarchical levels in an ecosystem, comprising organisms sharing the same fxn in the food chain and the same nutritional relationship to the primary sources of energy=food chain
|
|
|
food chain
|
series of energy (initially from the Sun) transfers
|
|
|
at each level of the food chain, what causes energy lost?
|
respiration
|
|
|
producers
|
assimilate light energy from Sun, convert it to stored energy of the chemical bonds of carbohydrates; assimilate carbon from CO2 and add it to there biomass (talking to your plants)
|
|
|
primary productivity
|
rate of storage for each gram of carbon assimilated (39kJ of energy stored/g of Carbon assimilated)
|
|
|
GPP
|
gross primary production (total energy assimilated by primary producers)
|
|
|
GPP=?
|
NPP + R
|
|
|
R
|
Respiration; energy used for maintenance (most energy goes towards this)
|
|
|
NPP
|
net primary production; remaining energy stored as biomass [consumers are able to eat this]
|
|
|
how do we measure primary production?
|
harvest and gas exchange techniques
|
|
|
harvest techniques?
|
measure the biomass, so dry plants and weigh
|
|
|
gas exchange techniques?
|
either measure uptake of CO2 in the light or production of CO2 in the dark(R); add NPP + R to get GPP
|
|
|
why would you want to measure CO2 production in the dark?
|
easier because only going in one direction as photosynthesis is not occurring
|
|
|
what percentage of total sun energy is converted to biomass?
|
only 1-2% (under optimal conditions for photosynthesis; unlimited H2O and minerals) this is called the photosynthetic efficiency
|
|
|
what is the optimal temperature for photosynthetic efficiency in temperate? tropical?
|
16C and 38C
|
|
|
what happens to the energy not incorporated into the biomass?
|
98-99% is reflected, absorbed, or lost as heat to the biosphere
|
|
|
what does temperature do to R, rate of photosynthesis, GPP?
|
increases with temperature; NPP is not different at higher/lower temperatures
|
|
|
equation for net production efficiency?
|
NPP/GPP X 100
|
|
|
what proportion of GPP becomes stored biomass?
|
depends on the percentage lost to respiration; temperate: 75-85% and tropics 40-60%
|
|
|
how does temperature affect GPP lost to respiration?
|
as temperature increases the respiration rate increases
|
|
|
what percentage of GPP is lost to respiration?
|
30-85%
|
|
|
why does the average net production vary by climate?
|
because different respiration rates
|
|
|
what is transpiration efficiency?
|
amount of biomass [grams] made per [kg] of water lost to transpiration (NPP(g)/H2O(kg))
|
|
|
transpiration
|
movement of water through roots, plants and out of leaf stoma
|
|
|
what is the transpiration efficiency for the average plant?
|
2g of biomass/kg of water -->plants use a lot of water
|
|
|
what is the transpiration efficiency for drought tolerant plants?
|
can double that of average plants (4g/kg of water)
|
|
|
what factors can limit photosynthesis?
|
terrestrial (WATER); terrestrial and aquatic (MINERAL NUTRIENTS)
|
|
|
water stress
|
low water availability = water scarcity
|
|
|
how do plants react to water stress?
|
close stomates and restrict gas exchange (photosynthesis also stops)
|
|
|
what is the most common limiting resource?
|
Nitrogen
|
|
|
how has agriculture “solved” the limited availability of nitrogen?
|
supplements NPK fertilizer
|
|
|
NPK fertilizer
|
different ratios of Nitrogen, Phosphorus, and Potassium to achieve different goals
|
|
|
what does nitrogen in fertilizer cause?
|
leaf growth
|
|
|
what does phosphorus in fertilizer cause?
|
root growth
|
|
|
what does potassium in fertilizer cause?
|
growth of seeds and fruits
|
|
|
what mineral is most limited in freshwater? seawater?
|
potassium; nitrogen
|
|
|
relative to freshwater, saltwater has ? elements
|
very limited elements
|
|
|
eutrophication
|
BLOOM of phytoplankton of water body because added artificial or natural substances
|
|
|
describe the steps leading to the negative impact of eutrophication
|
too much algae (blocks sun), organisms die, decomposition (bacteria levels soar and hypoxia occurs), dead zone (hypoxic waters)
|
|
|
dead zone
|
areas of hypoxic waters (less than 2ppm dissolved oxygen)
|
|
|
which terrestrial ecosystems undergo the most photosynthesis?
|
swamps and marshes, tropical environments
|
|
|
what is the difference between a swamp and a marsh?
|
swamp = ‘tree’ wet; marsh= ‘grass’ wet
|
|
|
why does the swamp/marsh evidence of biomass?
|
every biomass is consumed immediately so the biomass is in other organisms
|
|
|
which aquatic ecosystems undergo the most photosyntheesis?
|
algal beds/reefs, estuaries, lakes/streams, continental shelf
|
|
|
continental shelf
|
extended perimeter of continents
|
|
|
chemosynthesis
|
production of energy via chemical reactions
|
|
|
chemoautotrophs
|
obtain energy via oxidation of inorganic substrates
|
|
|
sulfurbacteria
|
in thermal vents, oxidize H2S, S, SOx THIOBACILLUS
|
|
|
nitrifying bacteria
|
in the soil or water and oxidize ammonia to nitrate
|
|
|
ex of nitrifying bacteria of the soil and of the water
|
Nitrosomonas; Nitrosococcus
|
|
|
ferrobacillus oxidize
|
iron salts
|
|
|
methanosomonas oxidize
|
methane
|
|
|
deep sea hydrothermal vent communities
|
operate where no light, food chain based on chemosynthesis using H2S; includes clams, worms, crabs, fish supported by bacteria
|
|
|
ecological efficiency
|
percentage of energy in the biomass of a trophic level that is incorporated into the biomass of the next highest level
|
|
|
what is the typical ecological efficiency?
|
5-20% (so there is a pyramidal shape as less is transferred to successive levels
|
|
|
herbivore based
|
occurs typically in aquatic, relatively large animals feed on biomass; 60-99% of NPP to herbivores
|
|
|
detrivore based
|
microorganisms and small animals consume dead remains of plants and indigestible excretions of herbivores
|
|
|
in meadows ? % of NPP to detrivores? temperate forests?
|
88% ; 98% discrepancy b/c forests are composed of a lot of wood that herbivores cannot digest
|
|
|
herbivore ex
|
caterpillar
|
|
|
detrivore ex
|
dung beetle; earth worm; nymph, angelfish, semaphore crab
|
|
|
semaphore crab
|
detrivore that sifts through sediment and detritus
|
|
|
detritus
|
disintegrated debris
|
|
|
exploitation efficiency
|
% of NPP from lower level that is consumed by next higher level
|
|
|
NPP > ingestion then energy
|
accumulates
|
|
|
NPP = ingestion then
|
ingestion is 100% and there is a complete turnover os NO standing crop
|
|
|
egestion
|
taken in but spit out (shells, bones) made available for detrivores
|
|
|
excretion
|
wast, fiber, materials removes via sweat, urination, and defecation (for detritius food chain)
|
|
|
assimilation
|
food/energy could be used for either biomass or respiration
|
|
|
biomass
|
growth and reproduction
|
|
|
respiration
|
maintenance
|
|
|
assimilation efficiency
|
% of ingested food that is actually assimilated into biomass or for respiration; used to determine food qualtiy
|
|
|
high quality food
|
(60-90% assimilated) ex: sees and young leaves
|
|
|
medium quality food
|
older leaves, grass (30-40%) must eat a lot to get adequate nutrition
|
|
|
lowest quality food
|
15% wood (it’s all fiber and contains lignin); symbionts in termites gut digests wood
|
|
|
Net Production efficiency
|
% that goes into biomass from total assimilated
|
|
|
net production efficiency depends on % lost to ? of consumer
|
respiration
|
|
|
T/F the most efficient consumers have low repiration dematnds
|
TRUE
|
|
|
high net production efficiency
|
sedentary or cold blooded (up to 75%)
|
|
|
low net production efficiency
|
animals with a high metabolic demand (don’t store anything); small mammals, birds
|
|
|
hummingbirds
|
have net production efficiency of <1%; sip sugar (nectar) and are attracted to red
|
|
|
energy flows in ? direction; elements ?
|
one-way direction (from Sun): elements cycle
|
|
|
what elements are important for life?
|
CHONPS
|
|
|
biogeochemistry
|
how elements move in solid, liquid and gaseous form (everything comes from somewhere)
|
|
|
where can elements reside?
|
rock, soil, sediments, water, atmosphere, biomass, detritus (reservoirs)
|
|
|
flux
|
movement in and out
|
|
|
how to elements move around the globe?
|
wind, water, geological activity, organisms (we get on planes and poop somewhere else)
|
|
|
rapid cycling
|
biomass > air > biomass; CO2 is released into air via respiration and can be quickly taken up by plants for photosyntesis
|
|
|
slow cycling
|
ROCK: biomass > rock > soil > biomass think about CaCO3 in clam shells
|
|
|
how do we measure element cycling?
|
stem flow is measured as water flows down tree trunks, can measure what exactly reaches the forest floors
|
|
|
Hubbard Brook Ecosystem Study and measuring element cycling
|
streamflow elements in watershed w/ and w/o trees (w/o tress has more elements)
|
|
|
why is the CO2 level of Earth’s atmosphere relatively low?
|
Photosynthetic life on Earth removes CO2 and put into sediments and organic matter, fossil fuels
|
|
|
residence time
|
how long an element stays in a certain reservoir
|
|
|
which has the longer residence time C in sediments or atmosphere
|
C in sediments because remains in rocks on the ocean floor
|
|
|
Mars has ? and Venus has ? more CO2 than Earth
|
30X; 300,000X
|
|
|
describe some different processes to move carbon:
|
sediment > volcano > atmosphere; atmosphere > biomass > atmosphere (photosynthesis and respiration);
|
|
|
Global NPP =
|
385 Pitagrams of CO2 per year in biomass as a result of photosynthesis
|
|
|
Percentage of Global NPP in the ocean or on land?
|
land = 54% and ocean = 46% (most of Earth covered in water and there are lots of single celled photosyntheic organisms
|
|
|
how does CO2 return to the atmosphere?
|
R and decomposition of detritus
|
|
|
what is the ocean exchange?
|
movement of biomass from atmosphere > ocean > atmosphere
|
|
|
ocean sequestration?
|
atmosphere > ocean > sediment; 15% of NPP in ocean SINKS to deep ocean to form sediments
|
|
|
describe sediment > ocean > sediment
|
CO2 gas + water + limestone >> Ca2+ + 2HCO3- bicarbonate converts to limestone sediment and forms rock
|
|
|
what are the units we use to measure the Carbon cycle?
|
teraton (1 x 10^12 tons)
|
|
|
describe the carbon cycle and its balance
|
absent of human input it all balances: volcanos (2TT) + ocean output (90TT)= 92 input; assimilation = respiration = 35TT
|
|
|
how much TT do we add to atmosphere as a result of combustion and burning fossil fuels?
|
7TT/year
|
|
|
what level of CO2 was balanced at?
|
280ppm
|
|
|
unnatural means the sediment > atmosphere?
|
combustion/fossil fuels and cement making
|
|
|
in 2007, ? Pg C released; project ? Pg C/year by 2050
|
7 >>> 15
|
|
|
what percentage of anthropogenic global CO2 emissions does cement making account for?
|
5%
|
|
|
cement =
|
CaO + SiO2, CaO is derived from limestone sediments
|
|
|
what are some strategies to reduce CO2 in the atmosphere?
|
Geologic and Oceanic Sequestration; increase biological pump by iron enrichment
|
|
|
what are 2 U.S. experiments into geologic sequestration?
|
WVA Mountaineer Plant and Illinois Meredosia Plant; have pumped CO2 into sandstone although limestone cheaper and easier, begun 2009 and slated to begin 2012
|
|
|
how much water is on Earth?
|
1.4 million TT
|
|
|
what % of water is saltwater? freshwater?
|
97% saltwater; 3% freshwater
|
|
|
where are the relative locations of freshwater?
|
ice caps/glaciers > underground aquifers > lakes and rivers > soil moisture > water in atmosphere > water in living things
|
|
|
water cycle overview
|
sun warms > evap over ocean and land (ocean gives more) > cloud > rain > runoff > evap
|
|
|
how does vegetation change climate
|
w/o plants = no water vapor in air ....transpiration leads to cloud formation and rain right above plants
|
|
|
how is transpiration in the tropics?
|
high heat > high transpiration > lots of rain
|
|
|
percolation
|
after rains on lands > seeps underground > aquifers (water deposits) > water table for drinking water and irrigation
|
|
|
Phosphorus cycle
|
P in rock > in soil > plants uptake > animals eat biomass > die > P in soil LOCAL cycle, important and eutrophication
|
|
|
Sulfur cycle
|
S in rock > soil > plants take up > animals eat plants> die > in soil or GAS
|
|
|
why is S cycle different than P cycle?
|
S easily converts to gas GLOBAL cycle H2S and Sulfur dioxide, a lot of S in fossil fuels
|
|
|
sulfur pollution
|
acid rain, acid mine drainage (water runs through mine wastes forming SULFURIC ACID >> pollutes river and groundwater
|
|
|
nitrogen cycle
|
N2 (nitrogen fixation) ammoni(um) (nitrification) NO3 (assimilation) plants > decomposers (ammonification)
|
|
|
what do denitrifiers do?
|
take from nitrate form back to N gas
|
|
|
nitrogenase
|
enzymes of bacteria and cyanobacteria (inhibited by O2) uses to fix Nitrogen; cellulase breaks down cellulose
|
|
|
free living nitro fixer of soil
|
Azotobacter spp.
|
|
|
symbiotic nitro fixer of root nodules
|
Rhizobium spp.
|
|
|
epiphylls
|
symbiotic nitro fixer of leaf surface
|
|
|
lichens
|
symbiotic nitro fixer inside fungal hyphae
|
|
|
nitrogen pollution
|
N saturation
|
|
|
in the last 50 years what has led to N pollution?
|
industrial N fixation (fertilizer) and car exhausts
|
|
|
what is the effect of N saturation?
|
smog, elevated nitrate levels in drinking water (toxic), acid rain, eutrophication
|
