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Environmental Science Exam I Part 3
Terms in this set (72)
a network of relationships among parts, elements, or components
-interact with an influence one another
-exchange energy, matter or information
systems receive inputs + produce outputs
energy, matter or information
a circular process in which a system's output serves as input to that same system. negative and positive feedback loops do not mean bad and good.
negative feedback loop (most systems in nature)
output from a system moving in one direction acts as input the moves the system in the other direction. Input and output neutralize one another, stabilizes the system ex. predator-prey
positive feedback loop (rare in nature, common in systems altered by humans)
output from a system moving in one direction acts as input that moves the system in the same direction. input and output add to each other. drives system further toward one extreme or another. ex. melting sea ice
system actively receives inputs and produces outputs while maintaining the same size and state
system characteristics are not evident in the components alone, the whole is more than the sum of the parts
complex, interacting systems. No sharp boundaries. ex river systems consist of hundreds of smaller tributary subsystems.
Gulf's dead zone
region of water so depleted of oxygen that marine organisms are killed or driven away
low concentrations of dissolved oxygen in water. From fertilizer, fossil fuel emissions, runoff, sewage
Eutrophication: Run off from midwestern farms, homes, industry adds nutrients to Mississippi River =
1. phytoplankton to grow
2. bacteria eat dead phytoplankton + wastes
3. explosions of bacteria deplete oxygen =
4. fish + other aquatic organisms to suffocate
eutrophication: the process of nutrient over-enrichment leads to
-blooms of algae
-increased production of organic matter
-decomposition and hypoxia
eutrophication: sources of nitrogen and phosphorus
Agricultural sources: (chemical fertilizers, nitrogen-fixing crops, livestock manure) residential fertilizers, sewage treatment plants, street runoff, industrial and vehicle emissions.
all organisms and nonliving entities that occur and interact in a particular area at the same time.
-includes abiotic (non-living) and biotic components
-organisms are tightly intertwined with their chemical and physical environment through interactions and feedback loops
what do ecosystems do?
receive, process and transform inputs of energy while cycling and recycling matter
-outputs produced include heat, water, wastes
energy from the sun flows in one direction
arriving as radiation and leaving as heat
matter is recycled within ecosystem
through food-web relationships and decomposition
conversion of solar energy to chemical energy in sugars by autotrophs
gross primary production (GPP)
assimilation of energy by autotrophs
net primary production (NPP)
energy remaining after respiration which is used to generate biomass-available for consumption by heterotrophs
rate at which ecosystems generate biomass
high net primary productivity
ecosystems whose plants rapidly convert solar energy to biomass
NPP variation causes
global geographic patterns. NPP increases with temperature and precipitation on land, and with light and nutrients in aquatic ecosystems.
elements and compounds required for survival that are consumed by organisms
required in larger amounts
nutrients needed in smaller amount. e.g. everything needs copper
what do nutrients stimulate?
nitrogen and phosphorus are important
for plant and algal growth
the more important limiting factor for primary productivity in coastal ocean waters
how many dead zones occur globally?
how much money do fisheries lost in lost harvests per year?
human society depends on
healthy, functioning ecosystems, they provide goods and services we need to survive
soil formation, water and air purification, pollination, breakdown of some pollutants and waste, quality of life issues (inspiration, spiritual renewal), nutrient cycling
matter is circulated
nutrient (biogeochemical) cycles
the movement of nutrients through ecosystems
where nutrients resides for varying amounts of time (the residence time)
the rate at which materials move between pools. can change over time, is influenced by human activities
a pool that releases more nutrients than it accepts
a pool that accepts more nutrients than it releases
summarizes how liquid, gaseous and solid water flows through the environment
main reservoir for hydrologic cycle
water moves from aquatic and land systems into the atmosphere
release of water vapor by plants
precipitation, runoff, and surface water
water returns to Earth as rain or snow and flows into streams, oceans, etc.
underground reservoirs of sponge-like regions of rock and soil that hold groundwater
water found underground beneath layers of soil
Groundwater becomes exposed to the air where...
where the water table reaches the surface, exposed water runs off to the ocean or evaporates
human impacts on hydrologic cycle (4)
-removing forests and vegetation increases runoff and erosion, reduces, transpiration and lower water tables
-irrigating agricultural fields depletes rivers, lakes and streams and increases evaporation
-Damming rivers increases evaporation and infiltration
-the most threatening impact: overdrawing groundwater for drinking, irrigation, and industrial use
describes the route of carbon atoms through the environment
carbon cycle: photosynthesis by plants, algae and cyanobacteria
1. removes carbon dioxide from air and water 2. produces oxygen and carbohydrates
carbon cycle: respiration
returns carbon to the air and oceans = plants, consumers, and decomposers
what returns carbon to the sediment?
largest reservoir of carbon?
sediment, may be trapped for hundreds of millions of years
second largest reservoir of carbon?
where do aquatic organisms die and settle?
in sediment, older layers are buried and undergo high pressure, ultimately may be converted into fossil fuels
humans affecting carbon cycle
1. burning fossil fuels move carbon from ground to the air 2. cutting forest and burning field moves carbon from vegetation to air 2. CO2 reservoir is largest in the past 800,000 years, driving force behind climate change
nitrogen comprises ___%
78% of our atmosphere, it is contained in proteins, DNA and RNA
describes the routes that nitrogen atoms take through the environment, nitrogen gas cannot be used by most organisms
lightning or nitrogen-fixing bacteria combine (fix) nitrogen with hydrogen, to form ammonium which can be used in plants which turn it into protein, which we then eat
bacteria convert ammonium ions first into nitrite ions then into nitrate ions, plants can take up these ions
animals obtain nitrogen
by eating plants or other animals
decomposer obtain nitrogen
from dead and decaying plants or animals, releasing ammonium ions to nitrifying bacteria
convert nitrates in soil or water to gaseous nitrogen, releasing it back into the atmosphere
production of fertilizers by combining nitrogen and hydrogen to synthesize ammonia
fixing atmospheric nitrogen with fertilizers
increases emissions of greenhouse gases and smog, washes calcium and potassium out of soil, acidifies water and soils, moves nitrogen into terrestrial systems and oceans, changed estuaries and coastal ecosystems and fisheries
half of nitrogen entering environment
is of human origin
harmful algal bloom and hypoxia Research and Control act 1998
Called for an assessment of hypoxia in the dead zone.
solutions to dead zone outlined:
reduce nitrogen fertilizer use in Midwestern farms, use alternative crops + manage manure better, restore wetlands and create artificial ones, improve sewage treatment technologies, evaluate these approaches
understanding biogeochemical cycles is crucial
humans are significantly changing the ways these cycles function
most densely populated state, highest average commuting time, ppl live on the fence line of industry -> exposed a lot
Tom's River Book
Tom's River had anomaly of brain cancer in children- cause was farm fields dumped pesticides in water.
south bound brook redevelopment planning
1997-designated seven block area in need of redevelopment
1998-adopted redevelopment plan including GAF Factory site
2001-Sept agreement with Princeton Brownfields Redevelopment Co
2001-2003 testing GAF site, secure RAW approval from DEP
2002- developed design guidelines
2003- Matzel & Mumford selected
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