1. Chapter 7: Environmental Systems and Ecosystem Ecology

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

3. 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

4. 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

5. 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

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

7. 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

8. Primary Productivity Worldwide
grams of Carbon per meter squared per year

9. 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

10. 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

11. 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

12. 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

13. GIS integrates different features and human uses of an area for future development

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

15. 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

16. Carbon Cycle pool size: petagram (1015g)
fluxes: petagrams of C per year

17. 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.

18. 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

19. Phosphorus cycle pool sizes: teragrams (10-12g)
fluxes: teragrams of P per year

20. 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

21. Nitrogen Cycle pool sizes: teragrams (10-12g) of N
fluxes: teragram of N per year

22. 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)

23. Nitrogen Fixation since 1950

24. 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

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

26. Hydrologic Cycle pool size: cubic kilometers (km3)
fluxes: km3 per year

27. 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

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

29. 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

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

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

32. Tectonic Plates

33. Plate Boundaries
THE END