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Dive into the intricate web of relationships between living organisms and their environments. Learn about the levels of organization in biology, ecosystems, biogeochemical cycles, and human impacts on the environment.
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Ecology Dr. Jared Heidinger M.D. Ph.D. Masters of Ecology, Doctorate of ecology, undergraduate of ecology, know it all of ecology, full of it ecology…
Ecology – study of interrelationships b/w living organisms and b/w organisms and their abiotic environment
Levels of Organization in Biology • Ecosphere – global ecosystem • Biosphere – global community • Ecosystem – community and environ. • Community – group of populations (same place, same time) • Population – same species of organism (same area, same time) • Organism – individual living thing
Continued… • Organ system – groups of organs that carry out a function (eg. digestive system) • Organ – two or more tissues that work together at a function (eg. Kidney) • Tissue – groups of cells with similar structure and function (eg. Muscle) • Cell – basic unit of life
Continued… • Organelle – structures within cells • Molecule – group of atoms bonded together • Atom – basic unit of all matter
Other important definitions… • Species – organism which can interbreed and produce fertile offspring • Habitat – environment in which a species normally lives or the location of a living organism.
Ecosystems (community and environment) • Consists of: • biota (living things (eg. organisms from the five kingdoms)) • Abiota (non-living things (eg. Soil, water, air, weather))
Interrelationships within ecosystem • Biota affects biota: man eats fish
Abiota affects abiota: fire destroys nesting sites • Abiota affects abiota: water erodes rock
Within Ecosystem • Matter is cycled • C, H, N, O, P, S • Molecules cycle between biota and abiota (biogeochemical cycles) • Energy does NOT cycle • Enters by sun, travels through food chain, leaves as heat
Biogeochemical Cycles • All chemical elements in living organisms (mainly CHNOPS) are: • Part of biogeochemical cycles • Move through land, water and air
Continued • Biogeo. Cycles summarize movements of elements • Through the biota (via food chains) forming complex organic molecules • Through the abiota forming simpler reusable organic forms.
Continued • Affected by human activity resulting in: • Ozone depletion • Green house effect and global warming • Acid rain • Algal blooms • Biomagnification of pesticides
Phase 1 • Nitrogen fixation – conversion of atmospheric nitrogen (N2) to nitrates (NO3-) • Often NH3 is formed first • Mostly done by aerobic bacteria: • Some free-living in soil • Some symbiotic live in plant roots • Some industrial fixation for fertilizer
Phase 1 cont… • Legumes (beans, peas, alfalfa, clover) – have root nodules that containing N2 fixing bacteria • Mutualistic relationship – both organisms benefit (+/+) • Increase soil nitrates – farmers rotate their crops with these plants
Phase 2 • Nitrification • Process of changing NH3 to NO2- to NO3- • Done by bacteria in soil
Phase 3 • Denitrification – conversion of nitrates (NO3-) to 2N • Anaerobic bacteria do this • Lowers available nitrates for plants • Plants don’t grow as well • Aerate, plow, dig, anything to get some O2 back in soil helps to counteract the plot of the evil, evil denitrifying bacteria (not really evil, unless you are a gardener)
Final Thoughts • Animals get all nitrogen (eg. - found in protein, DNA) from plants • Need nitrogen fixation to survive
Farming • Breaks the natural nitrogen cycle by removing all of the plant matter at harvest • Less matter to decompose and replenish nitrogen • Results in the need to fertilize
Carbon Cycle • Often called carbon oxygen cycle • Interrelated • Major processes • Photosynthesis • Decomposition: breakdown of organic matter, mostly done by fungi and saprophytic bacteria • Combustion: mostly done by automobiles
Problems • Global Warming • Deforestation – causes decline in photosynthesis
Not the same • Greenhouse effect is a natural process. Without it we could not survive on earth. • Greenhouse gases (CO2, H2O vapour, CH4 (methane), nitrous oxide, CFC’s) help to keep heat (infrared radiation) close to the earth’s surface • Global warming an increase in the earth’s average temperature due to the burning of fossil fuels releasing excess amounts of CO2
Worst case scenario – warming is greatest at poles causing melting of ice caps • Ocean could rise by 100m resulting in flooding of coastal regions up to 150km inland • Change in climate could mess with agriculture as well.
Steps: • Evaporation – l to g • Transpiration – l to g from plants • Condensation – g to l form clouds • Transport – movement of clouds • Precipitation – rain, sleet, snow, etc. • Runoff – streams, lakes, rivers • Groundwater – aquifers, underground streams
Problems • Acid rain • Toxic waste dumping • Leaching (chemical compounds seep into underground water) • Deforestation • runoff increases, minerals run into streams, disrupting balance in ion concentrations in water • Transpiration rates are changed.
Phosphorous uses in Biota • Cell membranes (phospholipids) • Energy storage (ATP) • Genetic information (DNA, RNA)
in Abiota… • Phosphate ions (PO43-) combined with other elements in rock • Ions dissolved in water move with water cycle
Problems • Eutrophication
Energy Flow in the Biosphere • E flows through an ecosystem: • Enters as light, leaves as heat • Is transferred through the food chain.
Food Chain • Shows flow of energy thorough ecosystem • DIAGRAM