Environmental Sustainability Flashcards
Nutrients are _____________
any chemicals that are needed for the proper functioning of organisms.
The nutrient cycle is _____________
is a system where energy and matter are transferred between living organisms.
The 4 main Nutrient cycles are ________
Carbon, hydrogen, nitrogen, and oxygen
Carbon is exchanged between biotic and abiotic components by ___________
photosynthesis and respiration
Precipitation, collection, transpiration, evaporation, and condensation are examples of the pathway of cycling for ___________ nutrient
Hydrogen/water
Transpiration is _______________
The movement of water from the ground through plants and trees, being released by the leaves into the air
By the process of________________, nitrogen-fixing bacteria fix atmospheric nitrogen to ammonia and nitrifying bacteria convert ammonia to nitrate.
nitrogen fixation
Atmospheric nitrogen is converted to _____________directly by lightning and assimilated by plants
Nitrates
Denitrifying bacteria convert ammonia and nitrates to nitrogen and nitrous oxide by the process of _________________
denitrification
_____________________break down proteins and amino acids of dead and decaying organic matters and waste product
Decomposers
Black Blizzards are _________
Dust storms that increased from one a year to nearly 40 in the 1930’s
The dust bowl in the 1930’s was caused by
Mechanized farming techniques (plowing), drought, and wind
No-Till farming is an example of ____________
a sustainable farming method that helps nutrients stay put
In the past 50 years, nitrogen cycles have been drastically altered by the rapid increase in ________________applications
synthetic fertilizer
An ecosystem managed primarily for the production of food, fuel or fiber is called ________
An agroecosystem
Ecosystem services include_____________
a. Provisioning, supportive, cultural, and regulating qualities
b. Water quality and runoff control, soil fertility and maintenance, carbon storage
c. Climate regulation, biodiversity, eco-tourism, and medicinal plants
D. All of the above
The “4 R’s” of fertilizer application are:
Right source, right rate, right time, right place
NUE is______
a. Nutrient Use Efficiency
b. the primary metric used to evaluate how well plants take up available nutrients in a
cropping system
c. the recovery of the applied nutrient either in the harvestable biomass of the plant or in
the total aboveground biomass divided by the quantity of the applied nutrient that was
neither incorporated into plant biomass nor made available to subsequent crops
D. all of the above
NUE is _________
1 if there is no loss to the environment, a closed efficient system
Tightening the nutrient cycle refers to __________
Higher utilization of active forms of a nutrient, with less loss to the general
environment
A major source of nitrogen into agricultural systems is__________
Nitrogen fixing plants, plant residue, fertilizers
Efficient nutrient cycling in agroecosystems results in ___________
Soil conservation, high water quality, carbon sequestration, low losses, and a resilient ecosystem
Factors influencing nutrient cycles in agroecosystems include____________
a. Biophysical factors such as soil texture, mineralogy, depth to water table, climate
regime, and topography
b. Landscape arrangement including configuration (proximity to water bodies, path length)
and composition (natural vs managed)
c. Farm management such as tillage, field size, rotations, type of inputs, and water
management
D. All of the above
Farm management practices can help promote tighter nutrient cycling by improving the _______________properties that regulate nutrient transformations
a. biological,
b. physical,
c. Chemical
D. All of the above
Greater nutrient retention can be achieved by reducing________________
a. runoff,
b. erosion,
c. leaching,
D. all of the above
soil greenhouse gas emissions can be reduced by _______
a. enhancing soil organic matter content,
b. increasing microbial biomass,
c. increasing water holding capacity, and crop yields
d. all of the above
Erosion __________
Results in soil loss via wind or water and is closely linked to soil tillage
Trees incorporated into agricultural practices can result in ___________
Reduced leaching
The crop rooting zone refers to __________
The depth at which crop roots reach and can utilize nutrients in that area
Soil organic matter provides ecosystem services such as _____________ (circle all that apply)
a. binding sites for mobile NO3 and PO4
c. enhances water holding capacity
d. increases soil microbial biomass
Soil water holding capacity is influenced by soil texture in the following ways __________(circle all that apply)
a. Clay soils have small partial size, increasing water holding capacity
b. Sandy soils have smaller surface area for water to accumulate
c. Loam soils hold less water than clay, but more water than sand
d. In order from the least water runoff to the greatest: clay, loam then sand
Water holding capacity is ______________ (circle all that apply)
a. the total amount of water that a soil can hold at field capacity
c. controlled mainly by soil texture and soil organic matter content
Soils with higher water holding capacity_________
a. allow more time for biotic nutrient uptake
b. Allow for greater abiotic transformations
c. reduce N leaching losses
D. all of the above
Agroecosystem management practices include______________(circle all that apply)
a. Intercropping, agroforestry, cover cropping
c. Integrating crops and livestock, organic matter amendments, and conservation tillage
Conservation tillage is ______
a range of soil tillage practices that reduce or eliminate physical turnover of the soil and leave crop residues on the soil surfaces
Agroforestry is _________
the simultaneous cultivation of woody plants (trees or shrubs) and crops
integrating crops and livestock is _____________
agropastoral, silvopastoral, or agro-silvopastoral systems which combine crops and livestock, trees and livestock, and crops, trees, and livestock
Cover cropping is________________
the practice of planting a “service” crop at a time of the year when a cash crop is not
grown.
Nutrient cycling efficiency indicators include______________ (circle all that apply)
a. Reduction of runoff and erosion
b. Reduced leaching and low greenhouse gas emissions
c. Improved carbon storage and microbial biomass
d. Improved water holding capacity and improved crop yields
Intercropping _______
a. Reduces runoff and erosion
b. Improves microbial biomass
c. Improves crop yields
D. All of the above
Benefits of agroforestry include ________
a. Reduced runoff and erosion,
b. improved carbon storage,
c. improved microbial biomass
D. all of the above
Organic Matter amendments in the soil can result in _________
improved crop yields
Organic farming prohibits the use of______________; thus, organic farmers tend to rely on intensive tillage operations to control weeds
synthetic herbicides
a variety of _____________can be used as forage for dairy cows such as, triticale, a rye and wheat hybrid
cover crops
_____________ (which are common in the tropics) can improve feed quality and
digestibility and increase species richness and abundance at the farm-level while also providing climate change mitigation benefits
Leguminous trees
In agroforestry, trees provide multiple ecosystem services, including ________
a. creating microclimates
b. providing food for pollinators
c. reducing nutrient loss via leaching and erosion
D. all of the above
In agroforestry, tree pruning residues can
a. be further treated and stabilized as mulch or compost
b. be returned to the system as a soil amendment
c. be used to increase soil organic matter
D. all of the above
Nitrogen Fixation is ________
when Nitrogen from the air is converted to Ammonium (NH4)
_________bacteria is a bacterium that is important for nitrogen fixation
Rhizobium
Nitrogen ________________ usually occurs with rhizobium bacteria in legumes plant root nodules
Fixation
Diatomic Nitrogen is held together by
A triple bond
The _________________protein breaks Nitrogen (N2) apart
Molybdenum-iron
NH3 is _________
Ammonia
NO2 is ____
Nitrite
NO3 is _____
Nitrate
TIN is _________________ (circle all that apply)
a. Total Inorganic Nitrogen
c. Ammonia + Nitrite + Nitrate
Total Nitrogen is ______
Ammonia + Nitrite + Nitrate + organic Nitrogen
TKN is ______________ (circle all that apply)
a. Total Kjeldahl Nitrogen
b. Ammonia + Organic Nitrogen
The pH of water plays a role in the nitrogen cycle by____________(circle all that apply)
a. More acidic water (pH lower) favors NH4
c. More basic water (pH High) favors NH3
Nitrification is ___________
a 2 step process, where Ammonia is converted to Nitrite by autotrophic bacteria, and the Nitrite is converted to Nitrate by heterotrophic bacteria
Nitrate in the water can cause __________________(circle all that apply)
a. Eutrophication in natural ecosystems
c. “Blue Baby Syndrome” in infants
NH4NO3 is ________
Ammonium nitrate
Before human activities contributed to nitrogen fixation, the global nitrogen cycling in soils, vegetation, the atmosphere and oceans relied entirely on ________________(circle all that apply)
a. microbial biological fixation
b. lightning
Human activities contribute to the global nitrogen cycle at the beginning of the 20th century through combustion, which creates fixed nitrogen as NOx by _________________ (circle all that apply)
b. industrial NH3 production (by the Haber– Bosch process)
c. by growing nitrogen fixing crops
About _____________of all reactive nitrogen in the nitrogen cycle today are thought to be additions from human activity
2/3
Negative effects of anthropomorphic nitrogen additions include ____
a. directly contributing to radiative forcing of climate,
b. reductions in biodiversity at regional scales in terrestrial ecosystems
c. damage to human health through aerosols and ozone production
D. all of the above
Positive effects of anthropomorphic nitrogen additions include __________________ (circle all that apply)
b. sustaining the food supply to a global human population
c. stimulating global CO2 sequestration by terrestrial and marine ecosystems
Social costs of Nitrogen Pollution include__________________ (circle all that apply)
a. Climate change
b. Ari pollution
c. Surface water contamination
d. Groundwater contamination
Climate change will affect ___________________(circle all that apply)
a. temperature and rainfall (amount, frequency, seasonal distribution)
b. soil environmental conditions
c. site and landscape hydrology, vegetation cover and substrate supply.
d. Land use since farmers will adapt land use and land management as climate changes
Legume plants have _____
Root nodules containing nitrogen fixing bacteria
Organisms that help fix nitrogen include __________________(Circle all that apply)
b. Legumes plants, bryophytes, and lichens
c. Algae and bacteria
Projected global increases in temperature are therefore likely to be associated with
_____________________ in biological nitrogen fixation
Increase
Marine biological N fixation is performed by a diverse range of _______
diazotrophs in plankton, microbial mat communities, sea grasses, coral reefs and sea sediments
Cyanobacteria _____________ (circle all that apply)
a. Are also known as blue-green algae
b. Can grow to large puffs, sometimes visible to the naked eye
c. Are bacteria capable of oxygenic photosynthesis
d. Can regulate their buoyancy to access nutrients
Trichodesmium erythraeum _________
Is a nitrogen fixing type of cyanobacteria
Increasing temperatures will likely cause the rate of N fixation to increase because
______________(circle all that apply)
a. enzyme activity increases at higher temperatures
c. the increase in sea surface temperatures will lead to an expansion of habitat suitable for diazotrophs
Oceanic Nitrogen processes can be affected by _______
a. Oxygen, salinity, Trace metals and phosphorus, and windspeeds carrying dust that contain micronutrients also play a factor (increased drought and wind transport)
b. ocean stratification which may may lead to a decrease in nutrient upwelling
C. all of the above
Atmospheric Nitrogen ___________as Carbon Dioxide levels increase
Increase
Nitrogen fixation in marine ecosystems are predicted to increase due to ______
Decrease in pH
Nitrogen fixation in marine ecosystems are predicted to increase due to ____
CO2 increase
Nitrogen fixation in marine ecosystems are predicted to increase due to ________
Temperature increase leading to expansion of diazotroph habitat
Nitrogen fixation in marine ecosystems are predicted to increase due to ________
Temperature increase leading to faster enzyme activity
Nitrogen fixation in marine ecosystems are predicted to increase due to _____
Stratification leading to shortage of nutrients in surface waters
Nitrogen fixation in marine ecosystems are predicted to decrease due to _____
Increase in deposition of reactive nitrogen
Nitrogen fixation in marine ecosystems are predicted to decrease due to ____
Increase in nitrogen export from rivers
The underlying cause of increase active nitrogen can be linked to ______
population increase during the 21st century, resulting in the higher demand for food and other nitrogen-consuming activities (transport, heating and consumer goods)
Cooler ocean temperatures at the poles allow for _______
More gases such as NH3 to be dissolved
Warmer ocean temperatures near the equator allow for _______________(circle all that apply)
a. Less gases such as NH3 to be dissolved
c. Higher NH3 emissions into the atmosphere
d. Greater evaporation
The future ocean–atmosphere flux of NH3 will be affected by____________(circle all that apply)
a. increasing temperatures,
b. increasing terrestrial NH3 emissions,
c. and ocean acidification from elevated CO2 levels,
d. lowering the pH of the water
Lower pH results in a greater relative concentration of ______________in the ocean
ammonium
The future oceans may accumulate more reactive N, leading to ______
Eutrophication
Sources of atmospheric NOx (NO+NO2) are _____
soils, natural fires, lightning, transport from the stratosphere and combustion of fossil fuels
Nitrous oxide____________
a. Is a long-lived (114 yr) greenhouse gas,
b. contributs to 10 % of the global radiative forcing
c. is now the main cause of stratospheric O3 depletion
D. All of the above
N-fertilizer is responsible for ________
Rise in atmospheric NO2 concentrations from 270 to 319 ppb
___________ assist with denitrification in soils
Achaea, bacteria and fungi
____________areas are hotspots of denitrification as well as often hotspots of soil N2O emissions
Riparian (near rivers)
________is the microbial oxidation of NH+ 4 to nitrate (NO− 3 ), with hydroxylamine
and NO− 2 as essential intermediates
Nitrification
Increasing levels of atmospheric CO2 increases________________ of plant photosynthesis, resulting in increased soil moisture
Water use efficiency
The overall effect of atmospheric composition change (due to climate change) on denitrification is to________ denitrification
Increase
Higher kinetic energies associated with warmer temperatures mean reactions proceed
Faster
Gaseous organic nitrogen exists in the atmosphere in both oxidized (peroxy acetyl nitrate PAN, and related compounds) and reduced forms, including _________
a. Amines and amino acids
b. urea
c. particulate matter in rain and snow
D. all of the above
WSON stands for
Water-Soluble fraction of Organic Nitrogen
Organic Nitrogen can take the form of ______
a. the humic-like materials
b. amines, amino acids, urea, nitrophenols, alkyl amides
c. N-heterocyclic alkaloids and organic nitrates
D. All of the above
Atmospheric organic nitrogen sources are found in_____________(circle all that apply)
a. soil dust, including in this source both ON associated with soil organic matter itself and the adsorption of ON onto dust particles
b. biomass burning
c. marine emission both direct and via emissions of gaseous precursors
d. anthropogenic and agricultural sources
Increases in average temperatures would be expected to lead to
_______________atmospheric concentrations of volatile and semi-volatile organic compounds, including ON species
increase
Changes in agricultural practice could lead to large changes in ON emissions, e.g. changes in the use of urea as a fertilizer, or changes in the management of animal wastes. (increased population will _____________________ agricultural demand)
increased
Increases in the oxidized nitrogen (NOy ) content of the atmosphere would lead to
faster reaction and conversion of organic matter into N-containing material, probably in the aerosol phase, leading in turn to ______________ aerosol concentrations of ON
Increased
In order to reduce the amount of active nitrogen in the cycle, we need to
__________(circle all that apply)
a. increasing nitrogen use efficiency in agriculture, closing nutrient cycles at different levels
b. influencing consumer behavior towards reduced meat consumption
c. use technology to reduce emissions from different compartments
d. use spatial planning as a tool to optimize production and environmental protection.
Phosphorus, potassium, sulfur, magnesium, calcium, iron, boron, manganese, zinc, molybdenum, copper are examples of ________
Micronutrients
Factors influencing nutrients cycling in agroecosystems include___
Biophysical, landscape, farming
__________ is highly influenced by tilling, resulting in loss of soil and all nutrients
Erosion
_______________ is the downward movement of nutrients below roots, grass, crop, tree roots
Leaching
_________is the effects on soil texture and nutrient uptake
Water holding capacity
intercropping, agroforestry, cover cropping, integration of crops and livestock, organic matter amendments, and conservation tillage are examples of _________
agroecosystem management practices
Combining crops and livestock, livestock and trees, trees and annual crops are examples of _________
Increasing biodiversity in agriculture
reduced runoff and erosion, reduced leaching, low GHG emissions, improved C storage, improved microbial biomass, improved water holding capacity, improved yields are examples of ___________
indicators of nutrient cycling efficiency
cover crops, perennial crops, complementary species planting are examples of __________farming practices to reduce weeds
Organic
Atmospheric, nitrates, Nitrites, Ammonium, fixation, nitrification, assimilation, ammonification, denitrification, total nitrogen, organic nitrogen, TKN are all examples of _______
Parts of the nitrogen cycle
Atmospheric nitrogen is triple bonded, broken inside of cells with the molybdenum iron protein, making___________
Ammonia
Legumes plants have rhizobium bacteria that fix atmospheric nitrogen into ammonium, which is an example of ______
Nitrogen fixation
NH4(ammonium) -> NO3 (Nitrate), uses up oxygen to do so is an example of
______________
Nitrification
Bacteria groups including ____________are important to the nitrogen cycle (circle all
that apply)
a. Autotrophs
b. Heterotrophs
c. ammonia oxidizers
d. Nitrite oxidizers
Denitrification takes place in ___________ environments
Anoxic
Human activities have nearly _________________ the amount of nitrogen actively cycling through the system
Doubled
localized controls, no global contracts, farmers vs government are examples of
____________ related to Nitrogen
Policy
aerosols near the earth’s surface, acid rain, health effects, eutrophication, climate are examples of _____________related to Nitrogen
climate change
the Haber Bosh Process ____
is a way of fixing nitrogen for fertilizers
_________ will affect temperature, rainfall, soil, hydrology, vegetation, and land
use, all of which will affect the nitrogen cycle in different ways
climate change
Increased CO2 affects ________________ (circle all that apply)
a. plant transpiration
b. soil moisture
c. O3 concentrations
d. C sequestration
________ was at equilibrium before industrialization, primarily controlled by
rhizobium bacteria, lichens and bryophytes, legumes crops, and is temperature sensitive.
Terrestrial biological nitrogen fixation
__________ involves plankton, sea grasses, cyanobacteria, trichodesmium, CO2 increases, increased stratification, increased nitrogen fixation, light influences, temperature influences, stratification, oxygen, salinity, trace metals, dust, wind, CO2, ammonium assimilated by phytoplankton
Marine biological nitrogen fixation
______ involves Combustion, fertilizer, etc, doubled Nr from 1980-2010, and projected to increase more
Human nitrogen fixation
________ involves livestock, crops, and fertilizers, effectively “fertilizing the
atmosphere”
NH3 emissions
NOx sources include_________
soil, fire, lightning, fossil fuels
Archaea, bacteria, fungi, contribute to _____________ putting nitrogen back into the atmosphere (inert), occurs at riparian zones
Denitrification
It is predicted that under current practices, the Nitrogen “bank” in the atmosphere-inert, will get smaller, the active Nitrogen in the system will get _____________, and the rate of change will increase overall.
Larger
hemic materials, thousands of compounds, both oxidized and reduced, found in soil, dust, biomass burning, marine emissions, agriculture, anthropogenic, are examples of _________
Organic nitrogen
____________are any chemicals that are needed for the proper functioning of
organisms
Nutrients
Carbon, Hydrogen, Nitrogen, Oxygen are the 4 main _____
Nutrient cycles
Water needed for all life, freshwater, transpiration, evaporation, groundwater,
precipitation are parts of __________
Hydrologic cycle
nitrogen fixation, atmospheric, nitrates, nitrites, ammonium, decomposers, denitrifying bacteria, denitrification are steps in the ___________
Nitrogen cycle
Water quality, soil fertility, climate regulation, and biodiversity are examples of ______________
Ecosystem services
