Lab 9: Aquatic Pollution and Eutrophication Flashcards
What is a watershed?
the entire land area drained by a particular stream or stream system
How are watershed studies carried out?
inputs and outputs are measured in watersheds with impervious substrates (bedrock)
What kind of nutrient cycle in forested watershed?
closed
What are closed nutrient cycles like?
- low input, low outputs in stream water
- stream water quality is highest closest to source
- most mineral nutrients are recyles within forest ecosystem
What kind of nutrient cycle in deforested/manipulated watersheds?
open
What are open nutrient cycles like?
more inputs, less retained within formerly forested area, more outputs=higher nutrient loads in stream water
What is most secondary productivity in running streams due to?
allochthonous inputs from adjacent terrestrial ecosystem
What is a good indicator of high stream water quality?
high diversity of heterotrophic macroinvertebrates
What can lead to faculative anaerobic bacteria?
stagnation, shade, high nutrient input
What can anaerobic respiration produce?
H2S gase
What does natural pond succession assure
that open bodies of water are generally rate and transient in GA as nearly all in the state are manmade
When can eutrophication occur?
when algae grows fast due to inputs of limiting nutrients (N and P in particular)
When nutrients are exhausted what happens?
plant death, leading to decomposers consuming O2, creating anaerobic conditions -> fish kill
When does thermal stratification of lakes occur?
summer and winter with periods of mixing (mixus) in spring and fall
In the summer, what forms in the photic zone
a warmer, biotic rich layer where light can reach and photosynthesis can occur
