Historical Records of Changes in the Productivity of Lakes
Changes in climate and in the geomorphology of drainage basins in the past have altered water and nutrient budgets and, as a result, productivity and rates of eutrophication of lake ecosystems. In many cases, human activities have greatly accelerated these changes, but on a much shorter time scale. A record of the resulting alterations in chemistry, flora, and fauna is left in the sediments as static derivatives of dynamic systems. Paleolimnology assesses the sedimentary record and the diagenetic processes that may alter it. An ultimate goal is to gain insight into the past conditions that caused a lake to enter a different level of productivity.
Interpretations about past levels and conditions of productivity of an aquatic ecosystem can be made from analyses of the: (1) physical structure and mineralogy of sediments, (2) inorganic and organic chemical constituents of the sediments, and (3) preserved morphological remains of organisms. Paleontological records rarely are complete. Moreover, lake sediments contain materials from the atmosphere and the drainage basin. Sediments within the basin can be redistributed by water and wind movements. Some remains of interred organisms preserve at different rates under changing lake conditions; others do not preserve at all. In spite of these difficulties, which demand critical interpretation, much information about changes in lake metabolism can be gleaned from the sedimentary record. Accurate interpretation depends on thorough understanding of ongoing biological and physicochemical processes of lakes.
The amount of permanent sedimentation in a lake is the result of the difference between the various inputs from the drainage basin and from the atmosphere (including solar radiation) and the losses to the atmosphere and to drainage. The form and rate of sedimented materials are regulated largely by biogeochemical transformations within the lake basin. Rates of sedimentation may be estimated from: (1) an analysis of the vertical age distribution in sediments, (2) measurement of seston sedimented, and (3) difference in input/output budgets [e.g., Wetzel et al. (1972), White and Wetzel (1975), Moeller and Likens (1978), and Davis and Ford (1985)].
In this exercise, we shall examine relatively recent sediments in lake or reservoir systems. From analyses of selected chemical and biological characteristics of the sediments, insight into processes that have induced changes in productivity of the systems may emerge.
KeywordsDrainage Basin Surficial Sediment Tertiary Butyl Alcohol Plastic Liner Mirror Lake
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- Birks, H.J.B. and H.H. Birks. 1980. Plant macrofossils in quaternary lake sediments. Arch. Hydrobiol. Ergebn. Limnol 15.60 pp.Google Scholar
- Brown, C.A. 1960. Palynological Techniques. C.A. Brown, 1180 Stanford Ave., Baton Rouge, LA. 188 pp.Google Scholar
- Crisman, T.L. 1978. Reconstruction of past lacustrine environments based on the remains of aquatic invertebrates. In: D. Walker, Editor. Biology and Quarternary Environments. Australian Acad. Sciences, Canberra.Google Scholar
- Daley, R.J. 1973. Experimental characterization of lacustrine chlorophyll diagenesis. II. Bacterial, viral and herbivore grazing effects. Arch. Hydrobiol. 72:409–439.Google Scholar
- Daley, R.J. and S.R. Brown. 1973. Experimental characterization of lacustrine chlorophyll diagenesis. I. Physiological and environmental effects. Arch. Hydrobiol. 72:277–304.Google Scholar
- Davis, M.B. and M.S. Ford. 1985. Late-glacial and Holocene sedimentation, pp. 346–366. In: G.E. Likens, Editor. An Ecosystem Approach to Aquatic Ecology. Mirror Lake and its Environment. Springer-Verlag, New York.Google Scholar
- Davis, M.B., R.E. Moeller, G.E. Likens, J. Ford, J. Sherman, and C. Goulden. 1985. Paleo-ecology of Mirror Lake and its watershed, pp. 410–429. In: G.E. Likens, Editor. An Ecosystem Approach to Aquatic Ecology: Mirror Lake and its Environment. Springer-Verlag, New York.Google Scholar
- Faegri, K. and J. Iversen. 1964. Textbook of Pollen Analysis. 2nd Ed. Hafner, New York. 237 pp.Google Scholar
- Frey, D.G. 1974. Paleolimnology. Mitt. Int. Ver. Limnol. 20:95–123.Google Scholar
- Kapp, R.O. 1969. How to Know the Pollen and Spores. W.C. Brown Co., Dubuque, IA. 249 pp.Google Scholar
- Kummel, B. and D. Raup (eds). 1965. Handbook of Paleontological Techniques. Freeman, New York. 852 pp.Google Scholar
- Manny, B.A., R.G. Wetzel, and R.E. Bailey. 1978. Paleolimnological sedimentation of organic carbon, nitrogen, phosphorus, fossil pigments, pollen, and diatoms in a hypereutrophic, hardwater lake: A case history of eutrophication. 2nd Int. Symp. on Paleolimnology. Polskie Arch. Hydrobiol. 25:243–267.Google Scholar
- Moeller, R.E. and G.E. Likens. 1978. Seston sedimentation in Mirror Lake, New Hampshire, and its relationship to long-term sediment accumulation. Verh. Int. Ver. Limnol. 20:525–530.Google Scholar
- Stockner, J.G. 1972. Paleolimnology as a means of assessing eutrophication. Verhand. Internat. Verein. Limnol. 18:1018–1030.Google Scholar
- Wetzel, R.G, P.H. Rich, M.C. Miller, and H.L. Allen. 1972. Metabolism of dissolved and particulate detrital carbon in a temperate hard-water lake. Mem. Ist. Ital. Idrobiol. 29 Suppl.: 185–243.Google Scholar
- White, W.S. and R.G. Wetzel. 1975. Nitrogen, phosphorus, particulate and colloidal carbon content of sedimenting seston of a hardwater lake. Verh. Int. Ver. Limnol. 19:330–339.Google Scholar