LEC 34 - DAMS Flashcards
what is a dam? why do we construct them?
dams are structures that stop flowing water and create a lakelike structure
primarily used for water retention, which can be used for hydroelectricity and other purposes
one of the experimental lakes was flooded. what were the results
nutrients that were trapped in soil were moved into the ecosystem, provided new vegetation for decomposition to occur - pretty straightforward
flood upland, midland, and valley areas. are the effects different? if so, how?
upland had lower levels of C, while valley had higher levels of C. across the board, CO2 and CH4 emissions increased, but esp in the high C reservoir (valley)
reservoirs can functionally be thought of as man made lakes. to what extent do they parallel lakes? diverge?
similarities
+ expect to develop thermoclines if deep enough
+ sediments should fall out of suspension since water is relatively slow moving
differences
- annual cycle of spring ice melt/winter ice cover is replaced by consistent fluctuations
- littoral zone will have trouble establishing since it gets drained pretty frequently
due to engineering logistics, it was found to be most practical to release water from the bottom of the reservoir. what implications does this have for animals such as invertebrates and macroinvertebrates?
(if stratified, which it prob is) will release cool, hypoxic water (and potentially regenerated nutrients) into the river
this can have big implications for the species that live in that river
invertebrates actually benefit bc they spend most their time in benthic, anoxic waters
macroinvertebrates get fucked up because their diapause cues (dormancy) get fucked up when they sense cold water
what are culverts? if they are supposed to be helpful, what is the problem?
culverts are those tunnels that move underground to connect water systems
the problem is, fragmentation persists (they dont do their job effectively)
what is an invasive species? what differentiates it from a nonnative species.
bonus: describe the zebra mussel example
invasive species: a species outside its normal habitat range that has established and propagated.
the difference is that nonnative species dont take root and spread
zebra mussels first somehow got in the great lakes. from there, through the mississippi river, they breached into chicago drainage basin and then pretty much all of eastern US
what are some pertinent ways that animals get spread around
aquarium culture, recreational fishing, ballast water
what is shelford’s law of tolerance?
there’s an optimal range where fitness is greatest - within this range animals can grow and even reproduce. however, as we move towards the ends and outside of this optimal range, animals cannot reproduce, or grow
