Freshwater Ecology Flashcards
Lentic System
An aquatic ecosystem that includes different forms of standing water.Examples: Lake, pond, bog, marsh, swamp, oxbow reservior, and playa lake.
Lotic system
An aquatic system that includes different forms of running water. Examples include rivers, streams and creeks
Lake
A large body of water where light penetration can be anywhere from several inches to many feet.Characteristics:
* Large and deep
* Water temperature causes layering during summer months
Texas;
* Texas only has ONE natural lake Caddo Lake
* The rest of the major lakes are reservoirs
Pond
A smaller, shallower body of water where light penetrates all the way to the bottom.Characteristics:
- Light penetrates to the bottom
- Shallower and smaller
- Tends to have uniform temperatures
BogPicture: Texas
A bog occurs when peat is formed in poorly drained areas. Small plants and moss characterize this habitat.
Marsh
A lentic system characterized by grasses and sedges.
Swamp
A lentic system that is characterized by trees such as cypress.Example: Caddo Lake
Oxbow Lake
These snake-like loops are cut off from the rest of the river and forms a long, narrow, crescent or U shaped lake.
Reservoir
A man-made lake used to store water. Most lakes in Texas are reservors. A reservoir is an artifical lake formed by the construction of a dam.Caddo Lake is Texas’s only natural lake.
Playa Lake
A desert lake that is periodically filled with water. Animals that live in the playa lake have adapted to the intermitent rain. Once the lake fills with water they must hatch, grow, mate and breed before the water evaporates.
Littoral Zone
The littoral zone is the vegetation area closest to the shore
Lemnitic Zone
The open water area of a lake or pond.
Profundal Zone
The profundal zone is the bottom area of lake. A place where light does not penetrate.
Succession
Succession is the natural aging of lakesand ponds. Overtime, sediment washes into a lake and starts to fill it up. As the lake becomes shallower, more plants grow around the edges of the lake. Given enough time the lake can fill in.Bogs, swamps and marshes can be considered the final stages of succession(climax communities) OR it can fill up completly and bcome a meadow.
Substrate
Rocks, logs, sediment are objects that other organims can attach themselves to, or sit upon
Sediment
Sediment is classified by the size of the particles. (smallest to largest)Examples: Silt, clay, pebbles, gravel, cobbles, bolders
Emergent Plants
Plants that are rooted witht he lower portion submerged and growing near the shore:Example: Bulrush
Free-floating plants
These plants float on the surface of the water and have “water” roots. The roots hang in the water and are not in the sediment.
Floating Plant
Floating plants have leaves and flowers on the surface and their roots are in the sediment.Example: Water Lily
Submerged Plants
Submerged plants are rooted plants with nearly all leaves below the surface.Example: Coontail
What is the euphotic zone?
The upper layer of the lake where light penetrates
What is productivity?
Productivity is related to the amount of plants, animals and nutrients in the waterLimiting factor: plant nutrients (nitrgen and phosphorus in a lake are important in limiting growth of planktonic algae and other vegetationThree major categories of lakes based on productivity:
- Oligotrophic
- Mesotrophic
- Eutrophic
What are the characteristics of an “oligotrophic” lake?
An oligotrophic lake is a body of water:
* low in mineral nutrients
* low plant and plankton populations
* little organic material in the sediments
* low chlorphyll a levels ( means low plants)
HINT: The “O” in oligotrophic reminds you this is LOW in nutrients.
What is a mesotrophic lake?
A mesotrophic lake is a body of water with MODERATE amounts of nutrients.It is a transition stage from Oligotrophic to EutrophicHINT: The “M” for mesotrophic stands for MODERATE
