Environmental Biology Exam 2
objective is to ensure the contintuity of species an ecosystems regardless of their potential utility

managing a resource so it will continue to provide maximum benefit to humans in the long run


using a resource too much. can be detrimental to ecosystem
A chemical used to kill pests
Any Chemical used to kill insects
a pesicide that kills or prevents the growth of fungus
dichlorodiphenyltrichloroethane. the first and most widely used of the synthetic organic pesticides belonging to the chlorinated hydrocarbon class. 
integrated pest management
a program consisting of two or more mehtods of pest control carefully integrated and designed to avoid economic loss from pests. Its objective is to minimize the use of environmentally hazardous synthetic chemicals.

Alpha Particles


positively charged particle emitted from natural or radioactive isotopes
Beta Particle
Gamma Ray
electromagnetic radiation emitted during radioactive decay; extremely short wavelength
electromagnetic radiation of short wavelength produced when high speed electrons strike a solid target. 
Half Life
Amount of time it takes for half an isotope to decay
An siotope of an element that is unstable and that gives off radioactive emissions. 
Ionizing Radiation
Radiation that displaces ions in tissues. as it displaces them it leaves behind ions.
the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
anything that causes cancer
Anything that can cause mutations
Side-effect of having too much nitrate or phosphate from fertilizer or sewage.  Depletes amount of oxygen.
Ground Water
water in the ground that has filled the pores in rocks or soil
an underground layer of porous rock, sand, or other material that allows the movement of water between layers of nonporous rock or clay. Aquifers are frequently tapped for wells.
Limiting Nutrient
When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient.

Botanical Pesticide


hot pepper powder, nicotine, citrus oil

Organophosphate Pesticide


parathion, malathion,phorate,chlorpyrifos

Chlorinated Hydrocarbon pesticide


DDT, toxaphene,dieldrin, chlordane,lindane
soil profile
A vertical cross-section of the soil, exposing the various horizons.
soil horizons
Distinct layers within a soil that convey different properties to the soil and that derive from natural processes of soil formation. typically goes OAEBC
O Horizon
organic horizon, sometimes on top of A horizon in forests,made up of decaying plant residues, OAE wetlands have O over O
A Horizon
Surface mineral horizon, dark color due to organic residue, typically on top, humus
E Horizon
Horizon of eluviation, materials have been washed, light color, highly leached
B Horizon
Horizon of accumulation, illuviation, clay, iron, aluminum oxides washed in.
C Horizon
parent material
pore space
the part of soil that is comprised of air and water 20-30% water
The proportionate quantity of sand, silt, and clay in the mineral fraction of a soil
-Smaller particles are more easily eroded than large ones. Texture affects aggregation and moisture.
Effects of soil texture on the soil environment
1. movement and retention of water
2. movement of soil air
3. absorption of nutrients and pollutants
4. ease of tillage
Size ranges of sand,silt, and clay
Sand 2.0 -> .05 mm
Silt .05 -> .002 mm
Clay < .002 mm
the manner in which soil particles are assembled in aggregate form
aggregates generally are not erodible. Aggregate stability is important.
an individual aggregate 
1. Platy
2. Prismatic & Columnar
3.Blocky, angular, subangular
4. Granular and Crumb
5. Single-grain
1. Clay and organic matter
2. Particle orientation
3. Shrinking and swelling
4. Root forces
5. Ice crystals.
6. Animals and insects.
7. Cementing agents (iron)
Hydrogen Bonding
a weak attractive force that occurs between a hydrogen atom of one molecule and, usually, an oxygen atom of another molecule. it is responsible for holding water molecules together to produce the liquid and solid states. 
Capillary Action
a phenomenon associated with surface tension and resulting in the elevation or depression of liquids in capillaries
Field Capacity

-1/3 bar: the maximum amount of water a soil can hold against drainage

Permanant Wilting Point
-15 bar : the soil moisture level causing plants to wilt, even in cool moist air
a positively charged ion
a negatively charged ion
the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms
process in which water soaks into soil as opposed to running off the surface.
process of water seeping down through cracks and pores in soil or rock.
The Gradual breakdown of rock into smaller and smaller particles, caused by natural chemical, physical, and biological factors.
Sheet Erosion
The loss of a more or less even layer of soil from the land surface due to the impact of rain and runoff from a rainstorm.
Rill Erosion
Formed from runoff water, can plow over it and hide damage
Gully Erosion
Soil erosion produced by running water and resulting in the formation of a gully.
Mass movement
mud flow, rainfall and water adds mass to slope, water lubricates soil particles and they take off
Saltation of the Fine Sands
-jumping and spinning motion
-0.5 – 0.05mm (diam.) fine sand
-breaks more particles loose
Suspension Movement
-silts and clays can become suspended in the air
-loess deposits
Surface Creep
-movement of sand dunes
->0.5 to <1.0mm
Sustainable Agriculture
Agriculture that maintains the integrity of soil and water resources such that it can be continued indefinitely.
Crop Rotations
-Crop diversity
-Raw and sod crops
-legumes and Nitrogen fixation
-Soil aggregation
-Weed control
-Insect control
-Disease control
Geological Erosion
a natural process of leveling the land surface
Accelerated Erosion
results from human activities that disturb the soil surface and the vegetative covering of the soil. It is approximately 1000 times as fast as geologic erosion.
The layer of earths atmosphere from the surface to about 10 miles in altitude. is a well mixed site and source of our weather as well as a primary recipient of air pollutants.
The layer of earth’s atmosphere between 10 and 40 miles above the surface that contains the ozone shield. This layer mixes slowly and pollutants that enter it may remain for long periods of time
two steps involved in the process of soil erosion. Also list the various erosive agents involved in these two steps
Detachment: of individual particles from soil aggregates
Transport: of particles by erosive agents – wind or water. Particles are eventually deposited to form new soils or to fill lakes and reservoirs.
Explain Sustainable Agriculture

agriculture that maintains the integrity of soil and water resources such that it can be continued indefinitely.

Reason for concern:
-population increases
-Environmental concerns
-Development of marginal land
-Economic and political concerns

-Maintain and improve resource base
-Protect the environment
-Increase productivity
-Increase profitability
-Conserve energy
-Improve food quality and safety
-Create a viable socio economic infrastructure

-Crop rotation
-Nutrients management
-Weed control
-Insect and disease control

List methods of soil conservation that limit either detachment or transport of soil particles:
Limit Detachment:
a. vegetative cover
b. Improve soil organic matter
c. reduce or eliminate tillage

Limit transport:
a. reduce runoff
b. increase infiltration
c. rough surface
d. reduce slope

Biochemical Oxygen Demand
Runoff water from a field contains a small amount of decomposable organic matter. That organic matter can be measured with a 5-day BOD test. The dissolved O2 at the beginning of the test is 8 ppm. After 5 days of incubation the dissolved O2 is 1 ppm. What is the 5-day BOD of the runoff water?
Aluminosilicate clays and humus are important sources of cation exchange capacity in soils. Why is soil cation exchange capacity important to both natural and agricultural ecosystems?
Discuss energy use and conservation.
Contrast active and passive solar heating
Active solar heating is using solar energy panels to convert sunlight into usable energy and thus power a heater. Passive solar heating is using the sun’s warmth (through windows or on thermal materials) to trap heat energy and thus heat a space through convection.
What are the alternatives to using “chemical pesticides”?

1.  Biological Control

Maintenance of beneficial organisms

     Parasites – insect larva

     Predators – Lady bugs, birds

     Pathogens – Bacillus thuringiensis

Pheromone attractants

Release of Sterile males

Hormones to disrupt life cycle

2. Plant extracts

Pyrethrins,  Rotenone

3.  Oils and soaps

Petroleum and detergents

4.  Integrated pest management (IPM)

Know the biology of the pest!

Crop rotations

Planting and harvesting dates to avoid pests

Biological control

Predator – prey relationships

Introduction of beneficial insects

Scouting for pests, monitoring populations

Limited use of pesticides when necessary

 A 1000-kg car strikes a brick wall at a velocity of 2 m/s.  Calculate the kinetic energy.

A 1000-kg car is parked at the edge of a 10-m cliff.  Calculate the potential energy of the car 


What do we do about global climate change?
 List the gases that cause the enhanced greenhouse effect along with their sources and sinks.

A)Carbon Dioxide

sources:   Respiration, combustion, 

Burning fossil fuels (coal, oil, gas)  5,700 Tg/yr.

sinks:  Photosynthesis, soil organic matter, 

wetlands, dissolution in the oceans.


sources: Wetlands, rice paddies, ruminant 

animals, coal and gas production, burning, 

termites, landfills, aquatic systems.

sinks:Reaction with tropospheric OH.  Oxidation 

by soil microbes.

C)Nitrous Oxide

sources:  Microbial N transformations

Denitrification and nitrification are sources of 


Fertilizer N and N fixation


sinks: Photochemical decomposition in the 

stratosphere, denitrifiers.

D) Chlorofluorocarbons (CFC’s)

sources:Industrial synthesis, Aerosol spray cans,;

foams, solvents, refrigeration

sinks:;Photodissociation in the stratosphere

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