LECTER EXAM #3

Forest

Ecosystem dominated by trees

Primary (old-growth) forest

Mature, unharvested forest with high biodiversity

Secondary forest

Young regrowth forest after harvesting; lower biodiversity

Plantation forestry

Single-species, fast-growing tree monocultures

Even-aged stand

Trees of the same age and size

Uneven-aged stand

Trees of various ages and sizes

Concession

Rights sold by developing countries to extract timber

Maximum sustainable yield

Harvesting at about half the carrying capacity for maximum growth

Ecosystem-based management

Harvesting while attempting to minimize ecosystem damage

Adaptive management

Using data and experience to improve management practices

Clear-cutting

Removing all trees in an area at one time

Shelterwood system

Removing most trees while leaving some for shelter and erosion control

Seed tree method

Leaving selected trees to provide seeds for regrowth

Selection system

Removing only some trees and leaving most behind

Prescribed burn

Intentional controlled fire to reduce fuel loads

Snag

Standing dead tree

Salvage logging

Harvesting dead trees (snags)

Forest Stewardship Council (FSC)

Certification for sustainably harvested forest products

National Wildlife Refuge

Protected area where some resource extraction may occur under monitoring

Wilderness Area

Protected land where extraction is prohibited

Land trust

Land purchased and protected for conservation

Biosphere reserve

Protected area with core, buffer, and transition zones

Habitat fragmentation

Breaking habitats into smaller isolated pieces

SLOSS dilemma

Single Large Or Several Small reserves?

Corridor

Habitat connection that allows wildlife movement

Atmosphere

Thin layer of gases surrounding Earth

Troposphere

Lowest atmospheric layer; weather occurs here

Stratosphere

Second atmospheric layer; contains ozone layer

Weather

Short-term atmospheric conditions in a local area

Climate

Long-term atmospheric conditions over a larger region

Convective circulation

Temperature-driven movement of air

Thermal inversion

Warm air above cool air traps pollutants

Prevailing winds

Global wind patterns caused by pressure differences

Coriolis effect

Curving of winds caused by Earth's rotation

Primary air pollutant

Pollutant emitted directly into the atmosphere

Secondary air pollutant

Pollutant formed in the atmosphere from other pollutants

Residence time

How long a pollutant remains in the atmosphere

Industrial smog

Smog caused mainly by sulfur dioxide from fossil fuels

Photochemical smog

Smog formed from NOx, VOCs, and sunlight

Tropospheric ozone

Harmful ground-level ozone

Stratospheric ozone

Beneficial ozone layer that blocks UV radiation

CFCs

Chlorofluorocarbons; cause ozone depletion

Acid deposition

Deposition of acidic compounds from the atmosphere

SO2 (Sulfur dioxide)

Causes industrial smog and acid deposition

NOx (Nitrogen oxides)

Causes photochemical smog and tropospheric ozone

CO2 (Carbon dioxide)

Main greenhouse gas causing climate change

Clean Air Act

U.S. law regulating air pollution

Montreal Protocol

1987 treaty that reduced CFC production

Greenhouse effect

Heat trapped by gases in the atmosphere

Greenhouse gases

Gases that contribute to atmospheric warming

Global warming potential

Relative warming strength of a greenhouse gas compared to CO2

Mitigation

Actions that reduce greenhouse gas emissions

Adaptation

Actions that reduce damage from climate change

Carbon tax

Fee placed on carbon emissions

Cap-and-trade

System that limits emissions and allows trading permits

Limnology

Study of freshwater systems

Lotic habitat

Moving water system such as a river

Lentic habitat

Standing water system such as a lake

Freshwater

System containing little salt

Groundwater

Water located below Earth's surface

Surface water

Water located on Earth's surface

Natural spring

Groundwater flowing to the surface

Infiltration

Surface water moving into groundwater

Aquifer

Underground porous rock formation that stores water

Zone of aeration

Area where pores contain air

Zone of saturation

Area where pores contain water

Water table

Boundary between aeration and saturation zones

Confined aquifer

Aquifer beneath impermeable material

Unconfined aquifer

Aquifer without an impermeable layer above it

Watershed

Land area surrounding and draining into a waterbody

Runoff

Water flowing across land into water bodies

Floodplain

Area adjacent to a river that may flood

Littoral zone (lake)

Shallow area near shore with rooted plants

Limnetic zone

Sunlit open-water region of a lake

Profundal zone

Deep darker region of a lake

Benthic zone

Bottom substrate zone

Oligotrophic lake

Healthy lake with good oxygen and low nutrients

Eutrophic lake

Nutrient-rich lake with poor oxygen conditions

Eutrophication

Nutrient enrichment that can reduce oxygen and harm aquatic life

Aquatic succession

Predictable change in aquatic communities over time

Freshwater wetland

Area with a high water table

Marsh

Wetland dominated by grasses

Swamp

Wetland dominated by trees

Bog

Wetland dominated by floating vegetation

Oceanography

Study of oceans

Intertidal zone

Region between high and low tides

Pelagic zone

Open, free-swimming portion of the ocean

Photic zone

Sunlit upper layer of the ocean

Aphotic zone

Deep ocean zone with little or no light

Upwelling

Deep nutrient-rich water rises to the surface

Downwelling

Surface water sinks and carries oxygen downward

Thermohaline circulation

Global ocean circulation driven by temperature and salinity

Estuary

Where freshwater meets ocean water

Brackish water

Mixture of freshwater and saltwater

Coral reef

Symbiosis between coral animals and algae

Coral bleaching

Loss of algae from corals causing whitening

Ocean acidification

Decreasing ocean pH due to dissolved CO2

Consumptive water use

Water not returned to its source

Non-consumptive water use

Water returned to its source after use

Desalination

Removal of salt from seawater