Chapter 3 | Basics of Freshwater Ecosystem and Physiography of Flowing Water Flashcards
the organisms (biotic) and the non-living (abiotic)
environment they inhabit.
freshwater or aquatic ecosystem
is defined by the drainage or
catchment basin in which it exists.
freshwater ecosystem—whether it be a pond,
lake, stream, or river
USEPA
United States Environmental Protection Agency
a geographic area in which water,
sediments, and dissolved materials drain into a common
outlet
drainage basin
How can a drainage basin be identified?
by tracing a line along the highest elevations between two areas on a map, often a ridge
it causes streams on either side to
flow in different directions.
topographic dividing line or ridge
defines the physical transport of
water, sediment, and dissolved minerals into the common outlet,
drainage basin
a term that defines a complex system of components that affect water bodies in a given drainage basin
watershed
What is the dividing line between two drainage basins?
the Highest point of land between them
It slows the flow of water over land
Natural areas like forests and vegetation
It filters some impurities and decreased erosion
Forests and vegetation
Two general categories of freshwater ecosystem
Lotic and Lentic
Running water
Lotic
Standing water
Lentic
Has a one direction of Flow, upstream or downstream
Lotic
Has various flow, no particular direction
Lentic
Has rich in oxygen
Lotic
Oxygen depletion exists at times in deeper water
Lentic
Streams that have no tributaries flowing into them
First-order stream or headwater streams
A first-order stream joined by another first-order stream
Second-order stream
They are primarily characterized by flow
Streams and rivers
3 main types of streams
Perennial, intermittent, and ephemeral
Streams and rivers that flow year-round
Perennial
Streams and rivers that become dry for a period of a week or longer each year
Intermittent
Intermittent streams that regularly exist for only a short period of time are classified as ___________
Ephemeral streams
An important factor that allows some streams to maintain flow during dry weather
Water table
A subsurface zone
Aquifers
What does aquifers store?
Groundwater
The upper area near the surface of the aquifer
Water table
When the water table is at or very close to the surface of the earth
Gaining stream
When the water table falls below the stream channel
Losing stream
2 Lotic habitats
- Lotic erosional
- Lotic depositional
Characterized by fast-running water
Lotic erosional
Characterized by areas of slow-moving water
Lotic depositional
This is the bend created when changing terrain alters the course of a river or stream
Meanders
it moves over time through the process of erosion and deposition
Meanders
Characteristic of the flow of the lotic erosional:
fast-moving , turbulent water
Riffle
Characteristic of the flow of the lotic erosional:
fast-moving, non-turbulent water
Run
Characteristic of the flow of the lotic erosional:
slow-moving water
Glide
Relatively deep and wide with slow moving water compared to riffles, runs, or glide
Lotic depositional
is the outer bank where flow velocities and bank erosion are high
Erosional zone
are intermediate habitat types that fall between riffles and pools
Glides and runs
referred to as laminar,
similar to that in a shallow canal
Glide
important habitats for many aquatic insects and small fish that require flowing water for feeding and high oxygen levels
Riffle areas
refers to the inner bank of a stream where velocity is at a minimum
Depositional zone
relatively deep and wide with slow-moving water compared to riffle, run, or glide areas
Pool
currents that move in a direction other than downstream, usually in a circular motion
Eddies
often contain large eddies
Pool
a vegetated buffet between nearby lands and a stream or river
Riparian Zone
include pools, riffles, root mats, aquatic plants, undercut banks, submerged rocks and logs, overchanging vegetation, and leaf litter.
In-stream habitats
Low diversity of aquatic life is often caused by poor?
Poor quality of in-stream habitats rather than poor water quality
