The Littoral Zone
297
c. In a laboratory, separate the vegetation from the sediments in large white enameled or
plastic trays and remove all macrofauna.
d. Sieve the sediments for benthic animals as outlined in Exercise 13.
e. Identify and enumerate the organisms found and calculate the numbers found per area
of littoral zone at the different sites.
f. If possible, determine the biomass of the different dominant taxa found.
g. Compare your results to those gathered for the open water sediments (Exercise 13).
7. Answer the questions following Option 2.
OPTION 2. ANALYSES OF LITTORAL HETEROGENEITY
1. Select two littoral sites of relatively homogeneous communities of aquatic macrophytes: one
among emergent macrophytes in standing water and another among submersed vegetation in
water of a depths of about 0.5 to 1 m.
2. Divide the class into five teams, each of which should analyze the different components, as
discussed in Option 1 for each team.
3. Emphasis in this option should be on obtaining good quantitative, replicated samples. A
minimum of three replicates should be taken at each site for each component sampled
(macrophytes, attached algae, zooplankton, phytoplankton, and benthic animals). Analyze
the samples as outlined in Option 1.
4. From the quantitative data, analyze each for the mean, range, standard deviation and
standard error of the mean, and coefficient of variation (see Appendix 2). Determine the
adequacy of sampling (cf., Appendix 2).
5. Answer the following questions.
Questions
1. How might you devise better methods to measure the living biomass of roots/rhizomes of
aquatic macrophytes? Why is this biomass important to computations of productivity?
2. How could one estimate turnover rates of organic matter produced by macrophytes:
a. During the season when plant tisue is being lost by sloughing?
b. Over several years among perennial plants when a portion of one or more year's growth
carries over to subsequent years?
3. When resources are limiting, does sampling along a transect or in a stratified random pattern
yield more information? Which approach provides greater statistical accuracy?
4. Based on yur biomass data, where is maximum productivity likely to occur among the three
major plant zones (emergent, floating-leaved, or submersed)?
5. When macrophytes senesce, what is the fate of both dissolved and particulate organic
detritus? Where would you anticipate the decomposition of each fraction to occur?
6. It has been demonstrated that submersed and floating-leaved macrophytes release significant
quantities of dissolved organic compounds and nutrients, such as nitrogen and phosphorus,
during active growth as well as during senescence. What are the implications of these
findings in relation to the use of artificial substrata for studying epiphytic algal growth?
7. Among heterogeneous attached algal populations, the extrapolation of changes in biomass
to estimates of productivity are complicated by many species of differing and variable
generation times. How could one reasonably estimate the composite population turnover
rates?
8. The epiphytic algae and bacteria are metabolically coupled to each other and to the
macrophyte. How might this symbiotic relationship function and be advantageous to all
biota included in the association?
9. As the large plants grow, new surfaces are available for epiphytic colonization. How would
these changes affect epiphytic populations (positively and negatively) and measurement
techniques?
297
c. In a laboratory, separate the vegetation from the sediments in large white enameled or
plastic trays and remove all macrofauna.
d. Sieve the sediments for benthic animals as outlined in Exercise 13.
e. Identify and enumerate the organisms found and calculate the numbers found per area
of littoral zone at the different sites.
f. If possible, determine the biomass of the different dominant taxa found.
g. Compare your results to those gathered for the open water sediments (Exercise 13).
7. Answer the questions following Option 2.
OPTION 2. ANALYSES OF LITTORAL HETEROGENEITY
1. Select two littoral sites of relatively homogeneous communities of aquatic macrophytes: one
among emergent macrophytes in standing water and another among submersed vegetation in
water of a depths of about 0.5 to 1 m.
2. Divide the class into five teams, each of which should analyze the different components, as
discussed in Option 1 for each team.
3. Emphasis in this option should be on obtaining good quantitative, replicated samples. A
minimum of three replicates should be taken at each site for each component sampled
(macrophytes, attached algae, zooplankton, phytoplankton, and benthic animals). Analyze
the samples as outlined in Option 1.
4. From the quantitative data, analyze each for the mean, range, standard deviation and
standard error of the mean, and coefficient of variation (see Appendix 2). Determine the
adequacy of sampling (cf., Appendix 2).
5. Answer the following questions.
Questions
1. How might you devise better methods to measure the living biomass of roots/rhizomes of
aquatic macrophytes? Why is this biomass important to computations of productivity?
2. How could one estimate turnover rates of organic matter produced by macrophytes:
a. During the season when plant tisue is being lost by sloughing?
b. Over several years among perennial plants when a portion of one or more year's growth
carries over to subsequent years?
3. When resources are limiting, does sampling along a transect or in a stratified random pattern
yield more information? Which approach provides greater statistical accuracy?
4. Based on yur biomass data, where is maximum productivity likely to occur among the three
major plant zones (emergent, floating-leaved, or submersed)?
5. When macrophytes senesce, what is the fate of both dissolved and particulate organic
detritus? Where would you anticipate the decomposition of each fraction to occur?
6. It has been demonstrated that submersed and floating-leaved macrophytes release significant
quantities of dissolved organic compounds and nutrients, such as nitrogen and phosphorus,
during active growth as well as during senescence. What are the implications of these
findings in relation to the use of artificial substrata for studying epiphytic algal growth?
7. Among heterogeneous attached algal populations, the extrapolation of changes in biomass
to estimates of productivity are complicated by many species of differing and variable
generation times. How could one reasonably estimate the composite population turnover
rates?
8. The epiphytic algae and bacteria are metabolically coupled to each other and to the
macrophyte. How might this symbiotic relationship function and be advantageous to all
biota included in the association?
9. As the large plants grow, new surfaces are available for epiphytic colonization. How would
these changes affect epiphytic populations (positively and negatively) and measurement
techniques?