摘要:

AbstractThe primary productivity of some lakes and reservoirs in western Labrador was measured by the14C method in order to determine the range of productivities and the effects of impoundment. No primary productivity data previously existed for this part of Canada. Both the primary productivity and standing crops of phytoplankton were found to be low in a newly impounded lake but later rose to levels greater than in surrounding natural lakes. In nutrient enrichment experiments, carbon was never found to be limiting but phosphorus stimulated primary productivity when added alone or in combination with nitrogen.

ISSN:0020-9309    

DOI:10.1002/iroh.19750600201

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

摘要:

AbstractDuring a limnological investigation of the Holland River, Holland Marsh and Cook Bay of Lake Simcoe (Ontario, Canada), an evaluation was made of the magnitude and significance of nutrient contributions to the West Branch of the Holland River and to Cook Bay from mixed agricultural‐woodland, mixed agricultural‐urban, intensively cultivated marsh and uncultivated marsh subcatchment areas within the watershed. The importance of the “net input” concept is discussed in an attempt to assess the relative importance of contributions of nutrients from areas of different land use practices on the watershed. Recognizing the relatively high contribution of total phosphorus (2.1 kg P/ha yr) in drainage water pumped from the intensively cultivated marsh, changes in the management of the cultivated marsh are suggested which would conceivably reduce the phosphorus loss in drainage waters from thes

ISSN:0020-9309    

DOI:10.1002/iroh.19750600202

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

摘要:

AbstractOn the outer slope of a coral reef in the Great Barrier Reef, at a depth of 11‐12 in without artificial light, bright red and rose colours were observed to occur on coelenterates, because masses of floating luminescent bacteria in the environmen

ISSN:0020-9309    

DOI:10.1002/iroh.19750600203

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

摘要:

AbstractDuring investigations on the macrobenthos between 17° N and 26° N on the North West African continental shelf, abundant stocks ofBranchiostomawere found off Spanish Sahara (23° N‐25° N), on the d'Arguin Bank (21° N‐20° N) and off Gambia (12° N‐13° N). The lancelets were identified asBranchiostoma senegalense(WEBB, 1955) by means of statistical analyses. The lancelet populations occur at dephts down to about 40 m. Deeper regions are probably avoided because of the excessively high detritus content. Favourable environmental factors such as temperature, composition of the sediment and food supply permit high lancelet abundancies. Up to 9000 animals'm2were found in the population off Spanish Sahara. Rough calculations showed that the lancelet population comprises about 6 × 1012individuals with a biomass of 1.5 million tons. The potential natality amounts to about 45 × 10

ISSN:0020-9309    

DOI:10.1002/iroh.19750600204

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

摘要:

AbstractDuring the years 1964 and 1967–1972 the relationship between abundance, growth and production of the roach population in the Klíčava reservoir (Central Bohemia) was studied. Significant values for correlation coefficients were found for all variables. Noticeable variations in abundance were accompanied by similar variations in growth rate. Only the ascending part of the production‐abundance relationships was exa

ISSN:0020-9309    

DOI:10.1002/iroh.19750600205

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

摘要:

AbstractA revision of the Australian and Tasmanian members of the family Notonemouridae is given, studying the abundant material from several Australian and European collections and additional material obtained during the author's collecting trip to Australia and Tasmania in 1966. The family of Notonemouridae was hitherto only poorly known from this area (6 species). The following text gives descriptions of 16 species, 10 of them, and 4 genera, being new to science. The larvae of this family in Australia and Tasmania live in cold springs and rivers, especially on seepage areas in high mountains, where they climb on vertical rock surfaces; the adults are able to jump by means of their hind femora.

ISSN:0020-9309    

DOI:10.1002/iroh.19750600206

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

摘要:

AbstractA large number of microplankton samples has been collected during every season in the Gulf of Marseilles from 1960 to 1968 (water samples and net tows). The authors have examined them with ecological, quantitative and qualitative purposes. Only the last one is considered here. About seven hundred systematic units have been identified. The most diverse taxonomical, groups are the diatoms and dinoflagellates, which exhibit much more numerous taxa than tintinnids, coccolithophorids and silicoflagellates.

ISSN:0020-9309    

DOI:10.1002/iroh.19750600207

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19750600208

出版商:Akademie Verlag, Berlin    

年代:1975

数据来源: WILEY