Lecture 20 - Chpt. 24 - Aquatic ecosystems (freshwater) Flashcards
Classification of terrestrial systems is defined as what
dominant plant life forms
What is the classification of aquatic systems?
characteristics of the physical environment
Freshwater vs Marine (salt water)
Freshwater is rivers, streams, ponds, lakes, inland wetlands
marine is coastal vs open water systems
Lotic systems is what?
Rivers and streams
Lentic systems is what?
ponds
lakes
inland wetlands
Describe life in the littoral zone
Root aquatic plants can be
1. emergent
2. floating
3. or submerged
Describe life in limnetic zone
phytoplankton and zooplankton
fish
distribution depends on food supply and adaptations to temperature and DO
What are the 4 zones in water
- littoral zone
- limnetic zone
- profundal zone
- benthic zone
Why is life in the profundal zone difficult?
- large amounts of organic material can accumulate
- DO levels can be extremely low
- Anaerobic bacteria often predominate
- cold
What forms the base of the food web in the profundal zone?
dead organic material of plants, fishes, plankton
How do light, temperature, and DO change with depth?
The deeper you go the less light, colder temperatures, and low dissolved oxygen levels
What are the two extremes of nutrient availability in lake ecosystems?
- eutrophic
- oligotrophic
Describe Eutrophic lakes
- contain an abundance of nutrients
- derived from surrounding landscape
- nutrient inputs may be anthropogenic (agriculture)
Why are eutrophic lakes bad?
The example in class is showing a lake that appeared in Florida near a public gated area. They have to maintain it to look nice which means their is an abundant amount of fertilizer being put into the ground such as nitrogen or phosphorus.
- Causes it to be dirty looking, sediment back up
Define oligotrophic lakes
nutrient poor
deficient in one or more nutrients
What is the trick for remembering what ecosystems belong to Lotic?
Lotic = O
mOving
streams, watershed, rivers
Define watershed
a land area drained by a stream/river, can be subdivided
Define stream order
a way to discuss the number of tributaries contributing to a stream/river
Define streams
- tend to be narrow channels with banks on either side
- smaller than rivers
- composed of rifle and a pool habitat
What is a riffle and what type of water ?
- fast, well oxygenated water, primary production
- in streams
What is a pool in relation to a stream?
a slower moving, decomposition habitat (right after the riffle
Define rivers
- can be very wide and meandering (windy)
- often confined within wide floodplains, flooding be can regular or rare
- if its fast-moving, can carry and deposit abundant sediments
How do animals in lotic environments not get moved away?
through adaptations such as
plants:
1. holdfast (like a root in algal) 2. Filamentous - moves with the water but anchor
Animals:
1. snails - foot that secretes muscu and is sticky
2. insects cling to rocks
What are the four major feeding groups in stream invertebrates?
- shredders
- collectors
- grazers
- gougers
What are the two detrital food sources?
- CPOM - coarse particular organic matter
- FPOM - fine particulate organic matter
Define shredders
- feed on CPOM and the bacteria and fungi that covers it (rocks)
- help break down organic matter
Define collectors
- can be filtering or gathering
- consume FPOM
Define Grazers
- feed on algae covering rocks in the stream
- release FPOM as they scrape rocks
Define gougers
- burrow into and consume wood that has fallen into the stream
Who would you find with high woody inputs?
gougers
Who would you find where more sunlight reaches the stream?
grazers
who would you find near downstream areas where FPOM is produced?
collectors
Who would you find in areas with high allochthonous inputs?
shredders
What does allochthonous mean?
material that is imported into an ecosystem.
What does it mean when it changes that changes in a river happen along a continuum?
You need to survey all areas of the river (up stream, middle, downstream) to understand how
1. invertebrate communities
2. consumer communities.
3. sources of energetic inputs like CPOM, FPOM, and NPP)
are being affected
each area is different since its altered width, depth, velocity, and temperature
