Recycling processes that supply needed substances for the biosphere
Law of Conservation
Energy cannot be created or destroyed
May be changed from one form to another
Energy and matter are continually transformed in the biosphere
Life requires matter (chemicals) & energy.
Earth system is closed (to matter), but media (air and water) allow matter to flow between components (reservoirs).
Biogeochemical CYCLES transfer necessary nutrients and material to sustain life.
The system requires energy…
Which biogeochemical cycle is the “most obvious”?
Answer: B - Carbon plays the central role in the "reduction-oxidation battlefield" that we call life.
Water = central to every part of the biosphere
Only common substance that exists as solid, liquid, & gas at normal temperatures
Large amounts of heat energy is transferred
All living things are water (70% humans)
Water is stored in the atmosphere, hydrosphere, & lithosphere
Oceans = greatest reservoir
Precipitation: water that condenses from a vapor and falls as rain or snow on the earth’s surface
Runoff: the portion of precipitation on land that ultimately reaches streams; flow from a stream into another body of water
Evaporation: water converted from liquid form in to vapor; water transferred from a liquid water body (stream, lake, ocean, moisture in soil, etc.) into the atmosphere
Transpiration: the passage of water vapor from a living body into the atmosphere through a membrane or pores
Evapo-transpiration: the combination of evaporation and transpiration
97% of the water in the globe resides in the oceans 22% of precipitation occurs over land, and is greater than losses by evaporation and transpiration The processes of evaporation, transpiration, and precipitation cycle water through ecosystems 78% of precipitation occurs over ocean, which is less than losses by evaporation Water Cycle 97% of the water in the globe resides in the oceans 22% of precipitation occurs over land, and is greater than losses by evaporation and transpiration The processes of evaporation, transpiration, and precipitation cycle water through ecosystems 78% of precipitation occurs over ocean, which is less than losses by evaporation
If water is neither being created nor destroyed, then
the amount of water on earth is constant
we can make a water budget
In a water budget, we select an area or volume of the earth and set up an “accounting ledger” for our “water account” for this area or volume.
Two rivers that fed the Aral Sea, the Amu Darya in the south and the Syr Darya in the northeast, would be diverted to irrigate the desert, in order to attempt to grow rice, melons, cereals, and cotton.
Enters through rock formation
Deposits of coal, petroleum, and natural gas derived from once-living things
CO2+H20+Energy = Carbs + O2
Carbs+O2 = CO2 + H20 + Energy (heat)
*Note: All living things need carbon and oxygen to sustain life
Cannot ignore the human affects on CO2 levels
Greenhouse gases Carbon dioxide is the largest single contributer to climate forcing Carbon dioxide contributes about half of total climate forcing from greenhouse gases
Inorganic-C in rocks (such as bicarbonate and carbonate)
Organic-C (such as found in organic plant material)
Carbon gases such as CO2 (carbon dioxide), CH4, (methane), and CO (carbon monoxide)
Porous layer of mineral and organic material, in which plants grow
Soils consists of:
Mineral particles – determine soil texture
Air and Water
Soils form from rock by ’weathering’
freezing, thawing, wetting, drying, organisms
dissolved minerals moved in water
soil horizons formed
1 inch = 100 years
Formed vertically (unlike layers of sediment)
O - organic horizons .
A - predominatly mineral horizon that is mixed with humified organic material (an eluvial horizon, i.e. a source of organic material, clay, and cations to lower horizons).
E - light colored, bleached mineral horizon underlying the A horizon that occurs only in highly leached acidic soils.
B - mineral horizon that shows little or no evidence of the original rock structure and which has been altered by oxidation, and illuviation (addition of minerals, clays, and organic matter from the A horizon).
K - a subsurface horizon that is characterized by accumulation of calcium carbonate. Occurs mostly in desert and dry areas.
C - a subsurface horizon that is basically the material from which the soil formed (loess, alluvium, till, etc.). It lacks most of the properties of the A or B horizon, but can be somewhat
R - regolith (consolidated bedrock).
Soils are classified into orders based on the presence or absence of diagnostic horizons and major differences in soil forming factors or properties.
There are 11 soil orders.
There are some soil orders that generally correspond to specific conditions:
Arid Organic Forests
Volcanic Highly oxidized Cracking
Frozen Prairie Young
Inceptisol – weakly developed soils often found in mountains Mollisol – grassland; plentiful organic material
Humid & Subtropical
Lost nutrients due to heavy precipitation
High in soluble materials
Low in organics
Midlatitude Subhumid Soils
Mountain Regions have poor soils due to heavy erosion
No continent is free of soil degradation
1.2 billion have moderately to severely degraded (especially Asia and Africa)
Central America highest percentage and worst degrees of soil degradation
Central part of USA very degraded soils
Intensive agriculture accelerates degradation (loss of nutrients)
Ability to support plant growth
Fallow period (no harvest; fields allowed to rest)
Inorganic fertilizers replace organic materials
Concern about impact on world’s food-producing capacity
Caused by climate change, erosion, and degradation of soil in dryland areas
Spreads outward from any where excessive abuse of the land occurs and far from any climatic desert
Poor irrigation practices and the unsustainable exploitation of water resources are contributing to chemical pollution, soil salinization and aquifer depletion.
The study of ecosystems mainly consists of the study of certain processes that link the living, or biotic, components to the
non-living, or abiotic, components.
Circle of Life Mufasa: Everything you see exists together, in a delicate balance. As king, you need to understand that balance, and respect all the creatures-- from the crawling ant to the leaping antelope. Simba: But, Dad, don't we eat the antelope? Mufasa: Yes, Simba, but let me explain. When we die, our bodies become the grass. And the antelope eat the grass. And so we are all connected in the great Circle of Life.
Ecosystem = a “major interacting system that involves both organisms and their nonliving environment" (Molles 2002) - who defines ecosystems as having the most complex level of biological organization. Biome = Widespread terrestrial ecosystems. Biomes are major communities of organisms that have a characteristic appearance and that are distributed over a wide land area defined largely by regional variations in climate.
Water or Moisture
Soil or Water
Biotic (Food Chain)
Primary Producers (autotrophs)
Omnivore (eats either other animals or plants)
All of these vary over space/time
Trophic Level – each step in the food chain
Succession is the natural transition of plant species from a "pioneer stage" to a "climax community" Beginning Stage Climax Community – End point (equilibrium)
Earth can be divided into Biomes
Occupy large regions
Plants & animals
Have specific climate with
similar plants and animal
Note: Many of the locations of these biomes on the map correspond to patterns of the annual precipitation and annual temperatures --->
* Some biomes and climate types share the same names