J. W. G. Lund

Bio: J. W. G. Lund is an academic researcher from Freshwater Biological Association. The author has contributed to research in topics: Algae & Population. The author has an hindex of 14, co-authored 20 publications receiving 3621 citations.

The inverted microscope method of estimating algal numbers and the statistical basis of estimations by counting

Abstract: Various methods for the estimation of populations of algae and other small freshwater organisms are described. A method of counting is described in detail. It is basically that of Utermohl and uses an inverted microscope. If the organisms are randomly distributed, a single count is sufficient to obtain an estimate of their abundance and confidence limits for this estimate, even if pipetting, dilution or concentration are involved. The errors in the actual counting and in converting colony counts to cell numbers are considered and found to be small relative to the random sampling error. Data are also given for a variant of Utermohl's method using a normal microscope and for a method of using a haemocytometer for the larger plankton algae.

The ecology of the freshwater phytoplankton

Abstract: Introduction . . . Light and temperature . Weather . . . . Water movements and flotation Inorganic nutrients . . ( I ) Nitrogen and phosphorus (2) Silicon . . . (3) Calcium and magnesium (4) Potassium . . . (5) Sulphate and chloride . (6) Iron and manganese . (7) Other trace metals , CONTENTS . 231 VI. . 232 . 238 . 239 VII. . 242 VIII. . 242 . 250 IX. . 253 x. . 254 XI. XII. * 255 . 255 . 257 XIII. General ionic environment . . 258 258

Botanical limnological methods with special reference to the algae

Abstract: I n t r o d u c t i o n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 Physical Environment and Energy Supply . . . . . . . . . . . . . . . . . . . . . . . . . . 493 Tempel\"ature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 Chemical Environment and Nutrient Supply . . . . . . . . . . . . . . . . . . . . . . . . 500 Photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 Quantitative Estimation of Plant Material . . . . . . . . . . . . . . . . . . . . . . . . . . 508 Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 Cell Constituents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 Chlorophyll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 Optical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 Other Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520 Interrelation of Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 Estimation of Growth in Natural Populations . . . . . . . . . . . . . . . . . . . . . . 522 Use of Experimental, Including Cultured, Populations . . . . . . . . . . . . . . 525 Mathematical Models of Population Behaviour . . . . . . . . . . . . . . . . . . . . . 531 Samples and Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Plankton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Benthos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539 Treatment of Collected Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 General Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 Plankton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 Benthos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 Postscript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548

Studies on plankton parasites

Abstract: PAGE A. Introduction. . .. .238 B. Methods .... .... 239 C. Parasitism . . . . . 240 D. The lakes and the periodicity of Asterionella . 24I E. Rhizophidium planktonicum and the periodicity of Asterionella 242 (i) Late summer to early spring . . 242 (ii) Early spring to summer 20. . . . F. Developmental phases of Rhizophidium in relation to epidemics 252 G. Behaviour of Rhizophidium under artificial conditions . 252 H. Extemal factors and the onset and course of epidemics of Rhizophidium planzktonicum in nature . . . . . . 255 I. Taxonomy of Rhizophidium planktonicum n.sp. (by H. M. Canter) 257 J. Summary . . . . . . 260 References .... ..... 260

Zur Vervollkommnung der quantitativen Phytoplankton-Methodik

Abstract: SynopsisAll the important questions in counting phytoplankton are reviewed. The methods described refer primarily to fresh water but are applicable to marine phytoplankton as well. No attempt has been made to review the whole of the voluminous literature on counting technique or describe its development. The main aim is to describe the counting-chamber method. The numerous difficulties encountered in quantitative plankton research are discussed and ways of avoiding them are described together with improvements of technique that save time. Among the equipment described are the filling-chamber (Fullkammer) and the combination-chamber (Verbundkammer). A mixture of potassium iodide in iodine and sodium acetate is used for the preservation of phytoplankton. A new sort of fractionated counting designed to overcome a certain degree of unavoidably uneven distribution of the plankton sediments is described.

Toxic cyanobacteria in water: a guide to their public health consequences, monitoring and management.

Abstract: This book describes the present state of knowledge regarding the impact of cyanobacteria on health through the use of water. It considers aspects of risk management and details the information needed for protecting drinking water sources and recreational water bodies from the health hazards caused by cyanobacteria and their toxins. It also outlines the state of knowledge regarding the principal considerations in the design of programmes and studies for monitoring water resources and supplies and describes the approaches and procedures used. The development of this publication was guided by the recommendations of several expert meetings concerning drinking water (Geneva, December 1995; Bad Elster, June 1996) and recreational water (Bad Elster, June 1996; St Helier, May 1997). An expert meeting in Bad Elster, April 1997, critically reviewed the literature concerning the toxicity of cyanotoxins and developed the scope and content of this book. A draft manuscript was reviewed at an editorial meeting in November 1997, and a further draft was reviewed by the working group responsible for updating the Guidelines for Drinkingwater Quality in March 1998.

The inverted microscope method of estimating algal numbers and the statistical basis of estimations by counting

Abstract: Various methods for the estimation of populations of algae and other small freshwater organisms are described. A method of counting is described in detail. It is basically that of Utermohl and uses an inverted microscope. If the organisms are randomly distributed, a single count is sufficient to obtain an estimate of their abundance and confidence limits for this estimate, even if pipetting, dilution or concentration are involved. The errors in the actual counting and in converting colony counts to cell numbers are considered and found to be small relative to the random sampling error. Data are also given for a variant of Utermohl's method using a normal microscope and for a method of using a haemocytometer for the larger plankton algae.

The Ecology of Phytoplankton

Abstract: Communities of microscopic plant life, or phytoplankton, dominate the Earth's aquatic ecosystems. This important new book by Colin Reynolds covers the adaptations, physiology and population dynamics of phytoplankton communities in lakes and rivers and oceans. It provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and in addition reviews recent advances in community ecology, developing an appreciation of assembly processes, co-existence and competition, disturbance and diversity. Although focussed on one group of organisms, the book develops many concepts relevant to ecology in the broadest sense, and as such will appeal to graduate students and researchers in ecology, limnology and oceanography.

Phytoplankton Community Ecology: The Role of Limiting Nutrients

Abstract: This paper is a summary and synthesis of the role of nutrients and spatial and temporal fluctuations in controlling the species composition, diversity, and seasonal succession of planktonic algal communities. We do not review the full breadth and depth of the literature that has appeared since the seminal papers by Hutchinson (34) and Dugdale (19). Rather, we focus on some of the major questions and hypotheses, and evaluate these in light of their consistency with observation and experimentation. Because the combined net effect of limiting nutrients, major ions, pH, and other physical factors ultimately determines the reproductive rate of a local algal population, we first briefly review the data on the role of these factors in phytoplankton ecology. We then review the theory of resource competition and apply it to the questions of equilibrium versus nonequilibrium approaches, seasonal succession, and multitrophic level effects in phytoplankton com-