Understanding Ecosystems and Human Impact

Classified in Biology

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Abiotic (physical, chemical), Biotic (population mateixa, community totes)

get food by: feeding, trophic relation shipsTrophic levels: 1) Producers 2)Consumers 3)Decomposers (bacteria, fungi)Organic materials: from living beings.
Photosynthesis: plants absorve inorganic matter(CO2, H2O, Sunlight) and produce organic matter (glucose, oxygen). Is produced in the clorophila (on cloroplasts). Nutritions: (1) autotrophs (photo and chemo), (2,3) heterotrophs (no photo)In a population relation of feeding: Cannibalism *mothers eat offspringChemoautotrophs: on acuatic volcanos 5km under sea,there were bacteria that do the chemosynthesi (because sunlight doesn't arrive): convert inorganic matter into organic through chemical substances (methane, sulfide) from volcano, thanks to that there could also live other organisms: worms, shrims and other strange fishes...Photoautotrophic: the ones that produce or. mat. from light source.çCellular respiration: process through all organisms feed/get energy from organic matter. Is produced in the mitochondria. Takes the glucose, its burnt with the oxygen to obtain the energy, and it releases CO2 and H2O(vaos al hivern). C6H12O6+6O2=6CO2+6H2O
CO2 increase: water acidifies, that causes bleaching and animals can't produce shells, also there is an increase in greenhouse effect, so temperature rises.If there is no greenhouse effect: earth will warm up a lot and at night we'll reach 18 degrees under zero. Greenhouse: sunlight enters and warms up the inside, so tomatoes can grow. Gases: CO2, CH4, N2O, CFCl

Gases cycles: 1)Carbon: is the main component in organic matter, CO2->organic matter i viceversa, fossil fuels (human activity)
2) Nitrogen: Is the main component in DNA and proteins, bacteria take atmospheric N, plants take that mineral N and turn it into organic matter, those pass it to decomposers and convert it into inorganic again. artificial, fertilizers
3)Phosphorus: Is the main component in DNA and lipid layer, bacteria take phosphorus rocks from floor and plants turn it into organic matter. fertilizers, detergents.
Guano Fertilizer: fish (organic matter)->birds''->feces''->bacteria (inorganic)->humans''->plants(organic)

Trophic parameters: 1)Biomass: amount of org. mat. that is part of an ecosystem at a moment in time (kg/m2)
2)Productivity: speed at wich the organisms in a ecosystem generate new org. mat. kg(m2·year). Primary: producers produce org. mat.  Secondary: consumers and decomposers incorporate organic matter.
Gross productivity: total amount of o.m that enters a trophic level, a portion is consumedin the same trop. level so not all is available for next level.
Net pro.: amount of o.m that a trop. level incorporates for growth minus the matter used for cellular respiration.
Net=gross-cellular respiration  /   gross=net+cellular repiration.
3)P/B ratio: compares net and biomass, in percentage, (forest=low). Compensation point: light intensity at wich the amount of CO2 of photo. matches the one released as waste of cellular respiration.

Trophic pyramids: number (in forest low producers), biomass (in ocean low producers), productivity (matches)

Human impact: 1)pollution: large amount of harmful wastes that end up in ecosystems.
2)climate change: CO2 makes that with gree. effect temperature increases.
3)Population imbalance: direcly by hunting and pesticides. indirectly introducing invasive species that cause mortality rates or uncontrollable growths (like processionaria: they line up)
4)Eutrophication: farmers use nitrogen and phosphorus fertilizers, rainwater carries the remains to lakes. Plants in lakes start growing , the ones on the top cover the sunlight so the ones below die, they convert in organic matter that fishes can eat. Org. mat. get descomposed by bacteria, those produce CO2 instead of O2, so fishes die.

Population Dynamics: 1)Competition: interespecific: from different species fight for feed. Intraespecific: of the same specie they fight for reproduction.
2)Mutualism:.help each other. *anemona-clownfish: that fish has developed a  skin that protect it from the anemona tentacles, previously appeara fish with a beneficial mutation (a protective wax on skin) that lasted. *humans-intestinal flora. *rinocerhos-birds.

Ecologycal succession: natural replacement process of species in communities of an ecosystem. Ends with the establishment of a stable community in dynamic equilibrium with its surrounding environment.

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