-A system is a network of relationships among parts, elements or components that interact
with and influence one another through the xchange of energy, matter or info.
-systems receive inputs of energy, matter or info and process them.
-open systems (open to both energy and matter - will take in energy(sunlight) and also
matter (water, carbon, oil, gas..etc) and also output the product of rxn of the inputs)
everything can be systems- e.g. this classroom, mouse
-closed system are those that receive inputs and produce outputs of energy but not matter.
(only opened to energy, not matter)the Earth is a closed system. the matter gets recycled and
eventually creates heat, Earth engulfs a lot of opened systems.
- matter cycles among system but does not leave or enter. but in nature there is no system
thats truly closed.
-feedback loop - a systems output can serve as an input to the same system. (e.g. earth has
its own feedback loops - not going to 3000 degrees.)
-negative feedback loop (enhence stability) results when the output of a system becomes the
input of the system thus moving the system in the opposite direction. inputs and outputs
essentially neutralize one another’s effects, stabilizing the system.
-positive feedback loop (destabilizing effect) rather than stabilizing a system, it drives it
further towards 1 extreme or another. E.g. population growth (more ppl born = more ppl to
give birth = more...etc). Rare in nature but common in natural systems altered by human
-dynamic equilibrium is when processes w/in a system move in opposite dir’n @
equivalent rates so their effects balance out. it’s an ever-changing balance not statistic
- homeostasis is the tendency of a system to maintain constant or stable internal conditions.
(in stable, steady state)
- emergent properties are characteristics thats not evident in the components alone.
-The earth can be broken down into a few sub-systems. such as the atmosphere-(air
surrounding our planet) everything above Earth’s surface. Lithosphere-(rock and sediment
beneath our feet, in the planet’s uppermost layers) everything below the surface, rocks...etc.
Biosphere-consists of all the living things and the non living portions which they interact
with. Hydrosphere-all the water based systems on earth (oceans, lakes rivers, ponds...etc)
All these systems’ boundaries overlap.
-Earth itself is a closed system, and these are all the opened systems w/in earth that interact
w/each other. Everything happens in the closed boundary of Earth itself.
-Over time, Rocks and minerals (naturally occurring, inorganic crystalline solids) are
heated, melted, cooled broken down and reassembled in a very slow process called the rock
cycle. (help determine biotic components of region’s ecosystem)
-All rocks can melt if T is high enough, liquid state of rock = magma, it amy flow or spatter
across Earth’s surface as lava. Cooled magma forms igneous rock.
-magma that cools slowly and solidifies under Earth’s surface is known as intrusive or
plutonic rock. (e.g. granite)
-magma from a volcano solidifies on the surface cools very quickly so minerals have little
time to grow into coarser crystals -> extrusive or volcanic rock. (e.g. basalt)
CHAPTER 5 - EARTH SYSTEMS AND ECOSYSTEM ECOLOGY