VII. Nutrient Cycling VII. Nutrient Cycling by by Matthew Matthew Steffenson Steffenson Living organisms require Living organisms require 30-40 30-40 elements elements for growth. for growth. Minerals flow through Minerals flow through biogeochemical biogeochemical cycles cycles . . • Bio Bio – Living. – Living. • Geo Geo – Water, rock, and soils. – Water, rock, and soils. • Chemical Chemical – Chemical processes. – Chemical processes. 2 Basic Types of Cycles: 2 Basic Types of Cycles: • Gaseous cycles Gaseous cycles – Includes carbon, – Includes carbon, nitrogen, oxygen, and water. nitrogen, oxygen, and water. • Sedimentary cycles Sedimentary cycles – Includes minerals. – Includes minerals.
Transcript
VII. Nutrient CyclingVII. Nutrient Cyclingbyby
Matthew Matthew SteffensonSteffenson
Living organisms require Living organisms require 30-40 elements30-40 elements for growth.for growth.
Minerals flow through Minerals flow through biogeochemical biogeochemical cyclescycles..• BioBio – Living. – Living.• GeoGeo – Water, rock, and soils. – Water, rock, and soils.• ChemicalChemical – Chemical processes. – Chemical processes.
2 Basic Types of Cycles:2 Basic Types of Cycles:• Gaseous cyclesGaseous cycles – Includes carbon, nitrogen, – Includes carbon, nitrogen,
oxygen, and water.oxygen, and water.• Sedimentary cyclesSedimentary cycles – Includes minerals. – Includes minerals.
Water CycleWater Cycle The interchange of water between air, The interchange of water between air,
land, sea, and between organisms and land, sea, and between organisms and their environment.their environment.
It is a It is a closed systemclosed system.. Important processes:Important processes:
• EvaporationEvaporation – Liquid to gas. – Liquid to gas.• PrecipitationPrecipitation – Rainfall/snowfall. – Rainfall/snowfall.• TranspirationTranspiration – Loss of water by plants. – Loss of water by plants.• Runoff and stream flowRunoff and stream flow• DiffusionDiffusion – Water drawn upwards through soil. – Water drawn upwards through soil.• PercolationPercolation – Water moving downwards – Water moving downwards
through soil to underground sources.through soil to underground sources.
Oxygen and Carbon CyclesOxygen and Carbon Cycles
Oxygen:Oxygen:• Water and oxygen Water and oxygen
cycle are related.cycle are related.
• 2H2H22O O 2H 2H22 + O + O22
Carbon:Carbon:• Carbon present in Carbon present in
all all organic organic compoundscompounds..
• Carbon is tied most Carbon is tied most directly to the flow directly to the flow of energy.of energy.
• Also tied in with Also tied in with water cycle (some water cycle (some dissolved COdissolved CO22 in in water).water).
Nitrogen CycleNitrogen Cycle
NN22 is the most common gas in the is the most common gas in the atmosphere.atmosphere.• Cannot be used by plants.Cannot be used by plants.
Important Organisms:Important Organisms:• Nitrogen fixersNitrogen fixers – Change N – Change N22 NO NO33
• Nitrifying organismsNitrifying organisms – Change NH – Change NH33 NO NO22 and and NONO22 NO NO33..
• Denitrifying organismsDenitrifying organisms – Change NO – Change NO33 N N22..
Generalized Cycle of Minerals and Generalized Cycle of Minerals and NutrientsNutrients
Cycle is sedimentary.Cycle is sedimentary.• Major reservoir for cycle is the Major reservoir for cycle is the earth’s earth’s
crustcrust.. Cycles are not closed within the Cycles are not closed within the
ecosystem (imports vs. exports).ecosystem (imports vs. exports).
Phosphorous CyclePhosphorous Cycle
Most likely to be a limiting factor.Most likely to be a limiting factor. Much phosphorous is lost as Much phosphorous is lost as
sediment in open ocean.sediment in open ocean. Some marine organisms help return Some marine organisms help return
phosphorous to land.phosphorous to land.• FishFish• Birds (feces is high in phosphorous)Birds (feces is high in phosphorous)• Ribbed mussel (filters phosphorous and Ribbed mussel (filters phosphorous and
deposits on mud flats)deposits on mud flats)
Cycling of Radioactive MaterialsCycling of Radioactive Materials Ionizing radiationIonizing radiation – Energy that travels – Energy that travels
through space and dissipates when through space and dissipates when passing through matter. Becomes passing through matter. Becomes charged by ejecting electrons when charged by ejecting electrons when passing through matter.passing through matter.
Sources of Radiation:Sources of Radiation:• CosmicCosmic – Low levels from space. – Low levels from space.• Natural radioactive particlesNatural radioactive particles – Naturally – Naturally
occurring elements such as uranium and occurring elements such as uranium and radium.radium.
• Man-madeMan-made – Examples include nuclear wastes – Examples include nuclear wastes and are the source of most environmental and are the source of most environmental problems.problems.
Types of RadiationTypes of Radiation
AlphaAlpha – Short distance traveling and – Short distance traveling and poor penetrating power.poor penetrating power.
BetaBeta – Short distance traveling and – Short distance traveling and poor penetrating power. If consumed poor penetrating power. If consumed or injected can cause serious or injected can cause serious problems.problems.
GammaGamma – Cause of most – Cause of most environmental problems. Travels environmental problems. Travels great distances and penetrates well.great distances and penetrates well.
Radiation ContinuedRadiation Continued
Primary effects of radiation are Primary effects of radiation are cellular and genetic.cellular and genetic.
Advanced organisms are more Advanced organisms are more sensitive to ionizing radiation in sensitive to ionizing radiation in general.general.
Simple organisms have less Simple organisms have less advanced cellular structure and advanced cellular structure and smaller chromosomes/nuclei and so smaller chromosomes/nuclei and so are less effected by radiation.are less effected by radiation.
Source of Radioactive MaterialsSource of Radioactive Materials
and create power as well as new elements and create power as well as new elements (strontium, cesium, etc.).(strontium, cesium, etc.).
Some of these particles last only a few Some of these particles last only a few seconds, some for thousands of years.seconds, some for thousands of years.
Some enter atmosphere and return to Some enter atmosphere and return to earth as atomic fallout. Others enter the earth as atomic fallout. Others enter the food chain.food chain.
Cycling of PesticidesCycling of Pesticides
Pesticides enter food chains.Pesticides enter food chains. Some synthetic chemicals cannot be Some synthetic chemicals cannot be
broken down and accumulate in the broken down and accumulate in the organisms tissues.organisms tissues.
Accumulation can be magnified up Accumulation can be magnified up the food chain (DDT).the food chain (DDT).• DDT banned in the U.S. in 1972.DDT banned in the U.S. in 1972.
VIII. Habitat and Niche ConceptsVIII. Habitat and Niche Concepts
HabitatHabitat – The place where an – The place where an organism lives.organism lives.
EnvironmentEnvironment – An organisms – An organisms surroundings.surroundings.
MicrohabitatMicrohabitat – The specific site an – The specific site an organisms occupies within its organisms occupies within its habitat.habitat.
NicheNiche – The role and organism plays – The role and organism plays in an ecosystem.in an ecosystem.
Niche ParametersNiche Parameters
Space (spatial niche)Space (spatial niche) – Roughly – Roughly equivalent to a microhabitat.equivalent to a microhabitat.
Food (trophic niche)Food (trophic niche) – Animals – Animals occurring in the same habitat often occurring in the same habitat often feed on different food resources.feed on different food resources.
Activity Periods (temporal niche)Activity Periods (temporal niche) – – Organisms may occupy the same Organisms may occupy the same habitat and feed on the same food habitat and feed on the same food resource, but at different times.resource, but at different times.
Gause’s RuleGause’s Rule
Also known as the Also known as the Competitive Competitive Exclusion PrincipleExclusion Principle. .
States that two species competing States that two species competing for the same niche cannot survive, for the same niche cannot survive, one must become extinct.one must become extinct.
One of the reasons for not One of the reasons for not introducing exotic species into a new introducing exotic species into a new environment.environment.
CompetitionCompetition
The interaction between 2 or more The interaction between 2 or more organisms trying to acquire the same organisms trying to acquire the same resources.resources.
2 Main Categories (Park 1962):2 Main Categories (Park 1962):• Exploitative competitionExploitative competition – Organisms – Organisms
use a resource until it become use a resource until it become unavailable to other organisms.unavailable to other organisms.
• Interference competitionInterference competition – Organisms – Organisms cause direct harm to other organisms.cause direct harm to other organisms.
6 Other Categories of Competition 6 Other Categories of Competition (Schoener 1983)(Schoener 1983)
Consumptive competitionConsumptive competition – For renewable – For renewable resources.resources.
Preemptive competitionPreemptive competition – For space. – For space. Overgrowth competitionOvergrowth competition – One organism grows on – One organism grows on
top of the other (i.e. plants competing for top of the other (i.e. plants competing for sunlight).sunlight).
Chemical competitionChemical competition – Releasing chemicals to – Releasing chemicals to reduce competition with other species.reduce competition with other species.
Territorial competitionTerritorial competition – Defense of space from – Defense of space from other organisms.other organisms.
Two Primary Levels of CompetitionTwo Primary Levels of Competition
Intraspecific competitionIntraspecific competition – Occurs between – Occurs between members of the same species.members of the same species.• Is a primary force shaping natural selection.Is a primary force shaping natural selection.• Is a primary population regulation mechanism Is a primary population regulation mechanism
in some populations.in some populations. Interspecific competitionInterspecific competition – Occurs between – Occurs between
members of a different species.members of a different species.• May not be as simplistic as one species May not be as simplistic as one species
outcompetes another to the point where one outcompetes another to the point where one species goes extinct.species goes extinct.
• Also shapes natural selection.Also shapes natural selection.• Influences how organisms coexist.Influences how organisms coexist.
The tendency for differences The tendency for differences between 2 species to be greater in between 2 species to be greater in areas of sympatry than areas of areas of sympatry than areas of allopatry.allopatry.• SympatrySympatry – Overlapping areas within the – Overlapping areas within the
range of 2 species.range of 2 species.• AllopatryAllopatry – Areas within the range of 2 – Areas within the range of 2
species that do not overlap.species that do not overlap. Can occur within any parameter of Can occur within any parameter of
the niche.the niche.
Ecological EquivalentsEcological Equivalents
Organisms that have the same role Organisms that have the same role (i.e. the same niche) but in different (i.e. the same niche) but in different ecosystems.ecosystems.
Evolve through a similar process of Evolve through a similar process of natural selection.natural selection.
Hypothetically the opposite of niche Hypothetically the opposite of niche divergence.divergence.
XVI. Adaptations to Sunlight or XVI. Adaptations to Sunlight or RadiationRadiation
Three Aspects of Sunlight:Three Aspects of Sunlight: QualityQuality – Composition of light of various wavelengths. – Composition of light of various wavelengths.
• Not much variability in terrestrial ecosystems.Not much variability in terrestrial ecosystems.• Wavelengths reach different depths in aquatic ecosystems.Wavelengths reach different depths in aquatic ecosystems.
IntensityIntensity – Amount of light reaching an organism. – Amount of light reaching an organism.• Essential to plants.Essential to plants.• Compensation intensityCompensation intensity – Level at which plants can no longer – Level at which plants can no longer
carry on sufficient photosynthesis.carry on sufficient photosynthesis. DurationDuration – Length of exposure. – Length of exposure.
• PhotoperiodPhotoperiod – Number of hours of daylight in a 24 hour period. – Number of hours of daylight in a 24 hour period.• Mainly influences reproductive and activity cycles (i.e. Mainly influences reproductive and activity cycles (i.e.
Adaptations to Water-Solute Adaptations to Water-Solute RelationshipsRelationships
Often related to mechanisms used in Often related to mechanisms used in thermoregulation.thermoregulation.
Mechanisms:Mechanisms:• Water intakeWater intake – Drinking, water in foods, – Drinking, water in foods,
metabolic water.metabolic water.• Water lossWater loss – Urine, perspiration, feces, saliva, – Urine, perspiration, feces, saliva,
etc. etc. • Solute intakeSolute intake – Ingestion of food, absorption in – Ingestion of food, absorption in
medium.medium.• Solute lossSolute loss – Perspiration, feces, urine, etc. – Perspiration, feces, urine, etc.
Adaptations of Freshwater and Adaptations of Freshwater and Saltwater OrganismsSaltwater Organisms
Freshwater:Freshwater:• Need to retain salts and Need to retain salts and
lose fluids.lose fluids.• High urine output with High urine output with
little drinking.little drinking.• Active transport of salt Active transport of salt
into bodies.into bodies.
Saltwater:Saltwater:• Need to lose salt and Need to lose salt and
retain fluids.retain fluids.• Drink high amounts of Drink high amounts of
water but excrete small water but excrete small amounts of amounts of concentrated urine.concentrated urine.
• Salt removed by some Salt removed by some fish with special gill fish with special gill cells.cells.
• Remove salt through Remove salt through tears (i.e. some birds tears (i.e. some birds and reptiles)and reptiles)
Adaptations of Terrestrial Adaptations of Terrestrial OrganismsOrganisms
Generally lose water and solutes.Generally lose water and solutes. Adaptations:Adaptations:
• BehavioralBehavioral – Organisms active only at certain – Organisms active only at certain times or seek areas with high water content.times or seek areas with high water content.
• PlantPlant – Shorter life cycles, special root systems, – Shorter life cycles, special root systems, stomata, etc.stomata, etc.
• PhysiologicalPhysiological – Efficient kidneys (camels), – Efficient kidneys (camels), flatworms encysting during dry periods.flatworms encysting during dry periods.
• MorphologicalMorphological – Tough integuments to reduce – Tough integuments to reduce dessication.dessication.
