a. ) Two key features of stream and river flow are extreme temporal variability, and the tendency to meander.
Explain how these create habitat diversity for aquatic organisms, through its effects on channel morphology,
sediment deposition, erosion, and the flood plain.
b.) With reference to the hydrological balance equation describe the effects of deforestation and upstream
lakes and wetlands on the amplitude and lag-time of the hydrographic responses of a stream to a storm-event.
c. )With reference to the hydrological balance equation explain why most streams on the landscape flow
continuously (albeit with huge variance) despite the episodic nature of precipitation. Contrast this with the
situation you might expect in a storm sewer—a man-made drainage system designed to conduct storm
runoff—which has high discharge for a few hours after a storm and then dries up completely.
a ) Habitat zonation in lakes is largely dependent on physical processes. Outline the role of wind and wave
action, light, and lake basin shape in determining the boundaries of the littoral zone, the thermocline, photic
zone depth and the boundaries of the depositional zone.
c.) Animals are often herbivorous and prey on plants and plants defend themselves by producing physical and
chemical defenses; however, many times mutualistic interactions between animals and plants have evolved.
Outline some examples of such mutualisms involving aquatic organisms, and explain why the physiological
processes of animals and plants and fundamentally compatible.
b. ) Show how the processes of photosynthetis and respiration are linked to changes in O2, and explain how
oxygen concentrations in a lake water column change throughout the daily cycle and how these changes can
be used to estimate the rates of photosynthesis and respiration of the lake community.
c. )Outline the general pattern of seasonal succession in lake phytoplankton, and explain it with reference to
seasonal changes in lake temperature and stratification, nutrient availability, and herbivorous zooplankton.
Outline the major ways that aquatic ecosystems provide free services to the human economy that are
difficult or impossible to replace with human-made substitutes.
Outline the role of wind and wave action, light, and lake basin shape in determining the boundaries of the
littoral zone, the thermocline, photic zone depth and the boundaries of the depositional zone.
With reference to the hydrological balance equation explain why most streams on the landscape flow
continuously (albeit with huge variance) despite the episodic nature of precipitation. Contrast this with the
situation you might expect in a storm sewer—a man-made drainage system designed to conduct storm
runoff—which has high discharge for a few hours after a storm and then dries up completely.
With reference to the hydrological balance equation describe the effects of deforestation and upstream lakes
and wetlands on the amplitude and lag-time of the hydrographic responses of a stream to a storm-event.
Two key features of stream and river flow are extreme temporal variability, and the tendency to meander.
Explain how these create habitat diversity for aquatic organisms, through its effects on channel morphology,
sediment deposition, erosion, and the flood plain.
Most lakes in the world are found in glaciated regions. Explain how glacial processes form lakes. Although
there are fewer lakes in non-glaciated regions, in what ways are they different from those in glaciated areas.
What are the factors that determine the apparent colour of a water. How would the colour of water be an
important environmental factor for photosynthetic organisms?
Diatoms by virtue of their siliceous cell walls have higher specific gravities than other small algae and have
virtually no ability to control their position in the water column. What are the consequences of this as
regard to the types of habitat they live in, their seasonal dynamics, and their responses to the thermal
regime.
Large colonial Cyanobacteria often bloom during the late summer in lakes. Describe some factors that
contribute to this general pattern.
What is meant by nitrogen fixation and why is it ecologically important. Explain which organisms can
perform this function and how they can exploit this capability in aquatic ecosystems. How have humans
exploited this in agriculture?
Explain how oxygen concentrations in a lake water column change throughout the daily cycle and how these
changes can be used to estimate the rates of photosynthesis and respiration of the lake community.