Studied by 79 people
lectures 11/6-11/20; textbook chapters 7, 9, 10, & 15; most definitions are pulled from the textbook
stock
a supply of something that we want to observe and measure over time
flows
the mechanism and rate by which a stock in a system changes over time
reinforcing feedback
a loop that responds to the direction of change in the stock by amplifying that same direction of change
balancing feedback
feedback that counteracts the direction in which a particular stock is changing
biogeochemical cycle
a path that shows how matter on Earth flows through different parts of the environment
macronutrients
an element that organisms require in large amounts: oxygen, phosphorus, nitrogen, & carbon
eutrophication
nitrogen fixation
a process where free nitrogen (N2) in the air is converted to soluble ammonia (NH4+) and nitrate (NO3-) ions that plants, algae, and bacteria can take in and use
ammonification
a process where bacteria and fungi break down nitrogen compounds in animal waste products and in dead plant and animal matter and release ammonia
nitrification
a process in which microorganisms convert ammonia to nitrogen compounds
denitrification
a process in which microorganisms use nitrogen compounds for respiration and create N2 gas, returning it to the atmosphere
Haber-Bosch reaction
a human-made, energy and resource-intensive process of nitrogen fixation that makes synthetic nitrogen fertilizer; draws on 1% of the world’s electricity output and 4% of the global natural gas supply
photosynthesis
a series of chemical reactions involving water and carbon dioxide through which plants and some other organisms store the Sun’s energy in simple sugars
green water
water in the soils that cycles through and supports plants; does NOT include irrigation!
blue water
standing/available water in the environment such as rivers, lakes, aquifers, precipitation, etc
transpiration
the process where plants use water in the soil and then expel it as water vapor
runoff
water/soil/other substances being carried away from the surface of an area of land
GPP
gross primary production; the rate at which autotrophs produce usable chemical energy
rock cycle
the geologic process by which Earth recycles and renews its surface
3 types of rock
sedimentary, igneous, and metamorphic
weathering
physical and chemical processes that reduce rocks to smaller particles and alter minerals
erosion
a process where natural forces — such as wind, water, ice, and gravity — move weathered rock particles
lithification
the process in which sediments compact under pressure and gradually become solid rock
sediment
eroded material that is transported and accumulates in different places
minerals
a natural solid from Earth’s crust that forms rock; also provides key materials for many practical human endeavors
landforms
a surface feature of the landscape
topography
the shape of the land
watershed
an area of land that drains to a particular point along a river or stream
floodplain
a place where floods frequently send water over the banks of a river or stream channel and deposit sediment
impervious surfaces
a surface that does not allow water to pass through it
soil
the medium in which plants grow; a complex mixture of weathered rock and mineral particles (sediment), dead & decaying plant and animal matter, and the multitude of organisms that live within these materials; has components of both litho and biosphere
infiltration
a process where water (or other liquid) moves down into the soil
loam
a mixture of roughly 40% sand, 40% silt, and 20% clay particles
soil horizons
a layer in soil created by the action of living (biotic) and nonliving (abiotic) factors
topsoil
typically the first 2-6 inches of soil, encompassing the top two soil horizons
detritus
fallen leaves and other dead organic matter that supports a vast community of life
humus
a form of detritus that is even more broken down and nutrient-rich
tilth
the soil’s overall structure and conditions that facilitate plant growth
salinization
when mineral salts build up in the soil
leaching
a process driven by water where mineral elements move down to deeper soil layers, potentially beneath the reach of plant roots, to be carried away in groundwater or stream flow
tilling
preparing the soil for planting by breaking it up and turning it over with a plow
autotrophs
organisms that produce their own food
NPP
net primary production; GPP minus the rate of energy lost to metabolism; the amount of energy stored as biomass
supporting services
fundamental ecological processes controlling structure and function of ecosystems
gaseous vs sedimentary macronutrients
gaseous: carbon, nitrogen, oxygen, water; sedimentary: phosphorus
lithosphere
rock component of the Earth
biosphere
the living component of Earth
soil profiles
the collection of soil horizons at a location
order of soil horizons (top to bottom)
O, A, B, C
watershed
an area of land that drains to a particular point along a river or stream
Note 
Flashcard (20)