Limnological Organic Analyses By Quantitative Dichromate Oxidation

A limnological oxidation technique, based on procedures employed in soil chemistry, was developed and tested by use of purified organic compounds and various natural substrates. A sample is oxidized by dichromate in a strongly acid medium maintained at 100 C. The amount of dichromate reacting (determined titrimetrically as the difference between the initial and final quantities) is reckoned as Oxygen Consumed, or weigh of oxygen required by the sample. The oxidation serves as the principal step for sensitive determinations of organic carbon (as CO2) and nitrogen (as NH3).

In this thoroughly updated third edition, the authors provide a series of carefully designed and tested field and laboratory exercises that represent the full scope of limnology. In using the text, students will gain a solid foundation in this complex, multidisciplinary field of ecology as they explore the physical, chemical, and biological characteristics of standing and running waters. The book illustrates accepted standard methods as well as modern metabolic and experimental approaches and their research applications. Each exercise is preceded by an introductory section and concludes with questions for students as well as suggestions for further reading. As a textbook, this is a highly structured, concise presentation with a research-oriented approach that openly invites active participation by students.

Limnological Analyses, a classic, second, thoroughly updated edition, consists of a series of carefully designed and tested field and laboratory exercises covering the full scope of limnology. It provides the student with a solid foundation in this complex multidisciplinary field of ecology and illustrates modern experimental approaches. Among the topics covered by such exercises are: major physical components of lakes and streams; important mineral nutrients; cycling of organic matter; benthic fauna; primary productivity of phytoplankton; quantitative methods in biota analysis; diurnal changes; experimental manipulation of model ecosystems; effects of sewage outfall and other human activities; whole ecosystem and community analyses. Each exercise is preceded by an introductory section and concludes with questions for the student and a selection of suggested reading. Teachers and students of limnology will value Limnological Analyses for its highly structured, concise presentation. Its research-oriented approach encourages active participation.

The Biology of Particles in Aquatic Systems, Second Edition presents the latest information on particulate and dissolved matter found in aquatic habitats ranging from small streams to oceans. Only by studying this matter can we gain an understanding of the functioning of aquatic ecosystems and thus be able to predict changes that may occur as these systems become stressed. Updated and extensively revised, this new edition covers such topics as classification of particulate and dissolved matter, origin and formation of particles aquatic systems, factors affecting particle aggregation, methods for capturing particles by benthic and planktonic animals, and the use of particulate and dissolved organic matter as food.

Rivers are recognized as major natural resources, not only as sources of domestic, industrial and agricultural water and hydro-electric power, but also for food production and increasingly for recreation and tourist promotion. This awareness has led to increased study of lotic limnology, particularly with respect to the development of the potentials of river systems. The concern over deterioration of watercourses as a result of poor land utilization and their use as repositories for man's rejectamenta has stimulated research into the basic dynamics of the river environment and its biotic communities. Before any assessment of pollution effects can be made, or rational remedial action suggested, there must be a sound, detailed knowledge of the 'natural' characteristics of regional water courses as a reference standard. This knowledge can result only from investigating the whole drainage area as a unit ecosystem (E VANS 1956) rather than just the specific conditions in the river itself (cf. SLACK 1955, HYNES 1969). Biotic data for any stream are of little value if divorced from consideration of the geology, hydrochemistry, land use and nutrient cycles of the watershed that generated them. The study of large rivers, potamobiology in the sense of I LLIES (1955, 1961 a), is a specialized area of research merging into lenitic ecology in many aspects and cannot be considered here.

The Biology of Particles in Aquatic Systems, Second Edition presents the latest information on particulate and dissolved matter found in aquatic habitats ranging from small streams to oceans. Only by studying this matter can we gain an understanding of the functioning of aquatic ecosystems and thus be able to predict changes that may occur as these systems become stressed. Updated and extensively revised, this new edition covers such topics as classification of particulate and dissolved matter, origin and formation of particles aquatic systems, factors affecting particle aggregation, methods for capturing particles by benthic and planktonic animals, and the use of particulate and dissolved organic matter as food.