Chapter 7: Environmental Systems and Ecosystem Ecology www.aw-bc.com/Withgott

Environmental Systems community ecology (different species) ecosystem level (living and non-living) environmental systems solar radiation geothermal activity organism's metabolism human activity pollution

Feedback Input: parts of a system that causes the condition observed freshwater sediments nutrients pollution Output: products obtained from the system matter and energy in the form of fish/shellfish

Feedback loop when the output of a system can become the input Negative feedback loop: input and output neutralize each other by dynamic equilibrium resulting in homeostasis (stabilized) thirst and drinking Positive feedback loop: drive the ecosystem to one of the extremes. Rare in nature but common when humans alter the environment erosion

Dead Zone area in which oxygen depletion is evident (hypoxia) normal oxygenated water has 10ppm depletion is 2ppm or less below 1.5ppm most organisms die caused by several factors urban runoff fertilizers municipal sewage industrial discharges fossil fuel emissions

Types of Environmental Systems lithosphere (rock and sediment) atmosphere (air) hydrosphere (water systems) biosphere (biotic and abiotic) they overlap in some way (Ecosystems)

Ecosystems interaction of living and non-living components energy (food) is converted into biomass (growth and repair) nutrients can limit productivity too much nitrogen causes dead zone in the gulf too much phosphorus causes dead zones in fresh water ponds and lakes iron seems to be the factor in open ocean waters

Primary Productivity Worldwide grams of Carbon per meter squared per year www.aw-bc.com/Withgott

Ecosystems Integration from small (simple pond) to large scale (biosphere) adjacent ecosystems may share components frogs develop in ponds, live in land and reproduce in pond salmon lives in the ocean but breeds in freshwater these areas where ecosystems meet are known as ecotones

Landscape Ecology study of different ecosystems that may affect abundance, distribution and interaction of organisms consists of patches and these can be of different scales subpopulations can live in different patches if a species move among patches to mate it is called a metapopulation metapopulation is used to study loss, protection and restoration of biodiversity

A corridor is shown between the marsh and the forest 5 ecosystems shown in large patches: 3 terrestrial, a marsh and a river A corridor is shown between the marsh and the forest Ecotone is shown between the grassland and forest showing patches in a smaller scale www.aw-bc.com/Withgott

Geographic Information System (GIS) software that takes multiple data geology, hydrology, vegetation, animal species, human development analyzes their location in the area of study analyzes their correlation and interactions with the other factors

GIS integrates different features and human uses of an area for future development www.aw-bc.com/Withgott

Biochemical Cycles carbon cycle nitrogen cycle water cycle phosphorus cycle rock cycle plate tectonics

Carbon Cycle photosynthesis: carbon is fixated in plant growth respiration: carbon is given back to the environment in the form of CO2 food webs: carbon is passed along sediment storage: remains settle to the bottom of the ocean producing fossil fuels oceans: absorb C from air, runoffs, volcanoes, waste and detritus of marine organisms. Ocean acidification

Carbon Cycle pool size: petagram (1015g) fluxes: petagrams of C per year www.aw-bc.com/Withgott

Shifting carbon from lithosphere to atmosphere producing more carbon in the air (CO2) by combustion than what is put back in the lithosphere carbon cycle cannot keep up cutting down forests and burning fields converts that carbon into CO2 releasing it to the air 1-2 billion metric tons of CO2 is unaccounted for, so it seems it is been taken up by plants scientists don't know what ecosystem is doing it right now.

Phosphorus Cycle essential for production of DNA, RNA, ATP and other molecules essential for life on earth present mainly lithosphere and ocean humans affect it by extracting it from the lithosphere and polluting the ocean with fertilizers

Phosphorus cycle pool sizes: teragrams (10-12g) fluxes: teragrams of P per year www.aw-bc.com/Withgott

Nitrogen Cycle 78% of the atmosphere mass as N2 essential ingredient for DNA and RNA essential for plant growth N2 is inert but once it transforms into NH3 (ammonia) or NH4+ (ammonium), it becomes "fixed" fixed molecules can be taken by plants (nitrogen fixation) nitrifying bacteria- puts nitrogen back in soil denitrifying bacteria- puts nitrogen back in atmosphere

Nitrogen Cycle pool sizes: teragrams (10-12g) of N fluxes: teragram of N per year www.aw-bc.com/Withgott

Human Influence in Nitrogen Cycle excess nitrogen from agriculture practices causes hypoxia dead zone in the gulf synthetic ammonia increased food production since 1950s factor in human population growth nitrogen fixation has been doubled NOx have increased in the atmosphere creating nitric acid (acid rain) and nitric oxide (smog)

Nitrogen Fixation since 1950 www.aw-bc.com/Withgott

Hydrologic Cycle essential for life key role in every cycle already studied 97% ocean, 3% fresh water carries nutrients carries sediments distributes pollutants evaporation, precipitation, groundwater

Forms of Fresh Water vapor liquid groundwater evaporation transpiration liquid precipitation runoff surface water (lakes, rivers) groundwater aquifers

Hydrologic Cycle pool size: cubic kilometers (km3) fluxes: km3 per year www.aw-bc.com/Withgott

Impacts on Hydrologic Cycle dams increase evaporation lake Mead levels dams alter vegetation Colorado river dams opening agricultural fields decrease water level in rivers and streams Rio Grande lower water tables Edwards aquifer pollutants present in water Rio Grande and aquifers conflicts for water Rio Grande delta, Colorado River

Geological Systems very slow process rock cycle igneous rock sedimentary rock metamorphic rock

Igneous Rock form from magma when it cools down it formes intrusive rocks multicolored formed by different similar minerals metamorphic and sedimentary granite is a good example

Sedimentary Rock formed by sediments and dissolved minerals weight and pressure aids its formation minerals act like glue metamorphic and igneous fossils and limestone

Metamorphic Rock changes form due to geological forces temperature and pressure sedimentary and igneous rock marble

Tectonic Plates www.aw-bc.com/Withgott

Plate Boundaries THE END www.aw-bc.com/Withgott