Ratio of natural isotopes of nitrogen. I. Primary results: soils of Dombes [Translation from: Revue d'Ecologie et de Biologie du Sol 14, 279-287, 1977]

Utilization of the heavy isotope of nitrogen as a tracer has found numerous applications in soil biology. It allows better definition of different stages of the nitrogen cycle, in particular the immobilization-mineralization cycle. In this work, the authors report the results of calculations of natural isotope ratios of nitrogen in samples of water, soil and vegetation prevailing in Dombes and discuss the possibilities of errors and coefficients of fractionation.

To the knowledge of the genus Pseudospora Cienkowski [Translation from: Archiv fur Protistenkunde 59, 350-368, 1927]

Morphological observations on the two types of Pseudospora are given. The two Pseudospora whic are described are Pseudospora eudorini and Pseudospora volvocis. The systematic classification of the genus Pseudospora is discussed.

Report of the Inter-American Tropical Tuna Commission for the year 1977

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a convention originally entered into by the Republic of Costa Rica and the United States of America. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas in the eastern Pacific Ocean. Under this provision the Republic of Panama adhered in 1953, the Republic of Ecuador in 1961, the United Mexican States in 1964, Canada in 1968 and Japan in 1970. In 1967, Ecuador gave notice of her intent to withdraw from the Commission, and her withdrawal became effective on August 21,1968. The Commission held two meetings in 1977, the 34th from June 27 to 29 in San Diego, California, and the 35th on October 17 and 18 in Mexico City. SPANISH: La Comisión Interamericana del Atún Tropical está bajo la autoridad y dirección de una convención la cual fue originalmente formada por la República de Costa Rica y los Estados Unidos de América. La Convención, vigente desde 1950, está abierta a la afiliación de otros gobiernos cuyos nacionales pesquen atún en el Pacífico oriental tropical. Bajo esta medida la República de Panamá se afilió en 1953, la República del Ecuador en 1961, los Estados Unidos Mexicanos en 1964, Canadá en 1968 y el Japón en 1970. En 1967, el Ecuador anunció su intención de retirarse de la Comisión y la renuncia se hizo efectiva el 21 de agosto de 1968. La Comisión celebró dos reuniones en 1977, la XXXIV del 27 al 29 de junio en San Diego (California) y la XXXV del 17 al 18 de octubre en ciudad de México. (PDF contains 156 pages).

Ecological study of chalk streams. Lambourn project. Interim report October 1977 to April 1979

Few detailed studies have been made on the ecology of the chalk streams. A complex community of plants and animals is present and much more information is required to achieve an understanding of the requirements and interactions of all the species. It is important that the rivers affected by this scheme should be studied and kept under continued observation so that any effects produced by the scheme can be detected. The report gives a synopsis of work carried out between 1971 and 1979 focusing on the present phase 1978-1979. It assumes some familiarity with the investigations carried out on the River Lambourn during the preceding years. The aims of the present phase of the project may be divided into two broad aspects. The first involves collecting further information in the field and includes three objectives: a continuation of studies on the Lambourn sites at Bagnor; comparative studies on other chalk streams; and a comparative study on a limestone stream. The second involves detailed analyses of data previously collected to document the recovery of the Lambourn from operational pumping and to attempt to develop simple conceptual and predictive models applicable over a wide range of physical and geographical variables. (PDF contains 43 pages)

Effects of flow regime on the young stages of Salmonid fishes. Conclusions based on results for 1977-1981

Rivers in Teesdale and its fish population have been monitored for several years. This report briefly describes the life cycle of British salmonid fishes and indicates the main ways in which this life cycle is influenced by discharge and related effects. Some highlights of the research results for 1977 - 1981 are briefly stated and proposals for future research are listed. Some practical implications of the results are discussed. (PDF contains 34 pages)

Ecological study of the River Lambourn. Report for the period October 1973 to September 1977

The investigations described in this report were carried out to fulfill three distinct but interrelated objectives. In 1973 the Thames Conservancy were making plans for a second stage of their groundwater scheme which would take water from the chalk aquifers in the valley of the Kennet and they wanted basic information on the ecological state of this river and its upper tributaries. Little appeared to be known about limestone streams and a preliminary study of one of the streams in this area was desirable as a basis for planning more detailed studies if these were needed later. At a progress meeting held in March 1976 the problems and opportunities presented by the developing drought conditions were considered. It was concluded that the ecological effects of the exceptionally low natural flows should be studied and that it would be important to assess the ecological impact of the groundwater scheme if it was brought into operation that year. This could only be done on the Lambourn and the Winterbourne and it was decided that considerable effort should be diverted there for this purpose and that the field observations should be extended to cover any recovery period after the end of the drought. To make this possible it was agreed that the studies of invertebrates and detritus on the Kennet should be reduced considerably and that the proposed study of the limestone stream should be abandoned. The revised objectives were as follows: A detailed ecological study of several sites on the Kennet and its tributaries above Kintbury, extending over at least two years and involving observations on wate r weeds , invertebrates, fish, detritus and the trophic relationships within the river community. Quantitativ e and qualitative sampling of water weeds and invertebrates during one year at a number of sites on several chalk streams to determine whether the patterns and relationships found in the Lambourn are also found at the other sites. Observations on the Lambourn at Bagnor were to continue for most of the period to look for long-term fluctuations and to enable these sites to act as controls with which the other sites could be compared. Further detailed studies on the Lambourn and the Winterbourne to assess the impact of low flows, trial pumping and the operation of the groundwater scheme.