摘要:

AbstractUsing the maximum quantum yield of photosynthesis, the maximum daily integral of photosynthetically active radiation (PAR) and the euphotic zone depth as a basis, general formulae for the upper limits to gross and net carbon fixation in natural waters are derived by theoretical considerations. The results are compared with a set of extremely high production data published by independently working authors, including data from algal mass cultures, oxidation ponds, freshwater and salt lakes, reservoirs, rivers and canals, coastal and other marine waters, including upwelling areas. The comparison reveals a quite surprising degree of agreement and suggests that the derived formulae represent a new, theoretically sound general approach to phytoplankton production. In particular, it can be shown that the upper limit to phytoplankton production in natural waters is about three times higher than earlier estimates in the literature. The maximum energy efficiency is of the same order of magnitude as in terrestrial plant communities.

ISSN:0020-9309    

DOI:10.1002/iroh.3510680602

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.3510680603

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractNegative correlations between clutch size and population density are proposed to be considered as indices of intra‐ and interspecific competition in cladocerans if they are revealed while analyzing population dynamics and clutch size and time lags are taken into account. The proper correlation analysis of summer populations ofDiaphanosoma brachyurum, Bosmina coregoni, Daphnia cucullataandD. galeatafrom mesotrophic Lake Glubokoye (Moscow Region) in 1975, 1978, and 1979 indicates the important role of competition of both types for the community studied. High niche overlap in food and space in the four populations was also observe

ISSN:0020-9309    

DOI:10.1002/iroh.3510680604

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractThe size structure of deep‐sea meio‐ and macrobenthos was studied using 12 USNEL box corer samples collected in the Western Pacific. Both macro‐ and meiobenthos decreased in abundance with increasing water depth, as expected, but contrary to previous findings, the rate of decrease did not differ significantly between the two size classes of organisms. The median size index of total meiobenthos decreased with increasing water depth, while when the vertical distribution of organisms in the sediment was considered, such a trend was restricted to the organisms found in the upper 1 cm layer. In contrast, the median size of the nematodes increased with increasing water depth, and a possible cause for this correlation is disc

ISSN:0020-9309    

DOI:10.1002/iroh.3510680605

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractPrimary production and decomposition of organic substances were investigated in a tropical lagoon during the rainy season. Production and mineralization were measured using the oxygen method. Total bacteria numbers and biomasses were estimated with epifluorescence microscopy, and the enzymatic degradation capacity of model substrates was determined photometrically. These parameters were measured in the water and sediment of the lagoon itself and also in its effluents and incoming waters. The aim of the study was to determine the sites of highest microbial activity in the lagoon and to compare its activity with other coastal water bodies. Since the shallow water lagoon contains a large amount of particulate matter, it was of special interest to study the degradation of this material and its influence on the microbial population. It was found that up to 14 % of the bacteria colonized the particles and that 62 % of the respiration originated in the particle fraction>8 μm. Highest exoenzymatic activities were measured in the sediment and water of the mangrove belt. It is concluded that decomposition and conditioning of particulate organic matter play dominant roles in the recycling of organic carbon in the lagoon

ISSN:0020-9309    

DOI:10.1002/iroh.3510680606

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractThe macrobenthic infauna of the Gulf of Arauco (Central Chile), was quantitatively sampled in April 1979. A total of 81 species were identified. The infauna was greatly dominated by polychaetes. The polychaeteParaprionospio pinnataand the amphipodAmpelisca araucanaaccounted forca. 45 per cent of the total infauna in terms of numbers. Numerical classification produced four site‐groups and four species‐groups, mostly reflecting differences in character and depth of sediment. Several community characteristics differed for these assemblages. Biomass also was dominated by polychaetes, withPectinaria chilensis, P. pinnata, Diopatra chiliensisandGlycera americanamaking up 45 per cent of the total. The high numbers of the fauna (mean = 15,021 ind m−2) and especially the high biomass figures (mean = 21.04 g AFDW m−2) reported are consistent with the high productivity of the area, subject to coastal upwelling pr

ISSN:0020-9309    

DOI:10.1002/iroh.3510680607

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractLamprocystis roseopersicinawas found to be the dominant phototrophic bacterium in meromictic Deadmoose Lake. Using carbon‐14 it was determined that phototrophic bacteria fixed 14.3 g C m−2year−1, 17.1 % of the total limnetic primary production. Experiments indicated low light intensities (X= 8.87 × 10−2cal cm−2hr−1) to be the most important factor limiting bacterial production.Lamprocystiswas shown to be capable of photoorganoheterotrophic uptak

ISSN:0020-9309    

DOI:10.1002/iroh.3510680608

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.3510680610

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractThe effects of artificial enrichment with nitrate, phosphate and EDTA on the phytoplankton community were studied in the Lobo Reservoir (São Paulo, Brazil). After 14 days ofin situincubation, the amounts of suspended matter and chlorophylla, the numbers of cells and the carotene/chlorophyll ratio were determined. The addition of nitrate and phosphate to water samples produced significant effects on the chlorophyllaand cell counts, while EDTA acted only on the cell production. Both nitrate and phosphate, when analysed individually, caused a decrease in the value of the carotene/chlorophyll ratio. A synergistic effect of the addition of EDTA and N on the suspended matter was observed

ISSN:0020-9309    

DOI:10.1002/iroh.3510680611

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractA hypothesis on spatial dynamics of pelagic crustacean plankters was tested with the copepods and cladocerans of Squire Pond, Ohio. There was an agreement between the expected and the observed pattern of overall horizontal distribution in most instances forMesocyclops edax, Tropocyclops prasinus mexicanus, Ceriodaphnia lacustris, Bosmina longirostrisand nauplii, but only in a few instances forDiaptomus pallidusandDaphnia parvula. Windward accumulation was common for the first 4 species and near uniform distribution was frequent for the nauplii. Vertical‐distribution trend along transect for all species rarely corresponded with the expectation. Alternation of modal depth along transect was one of the most frequently observed trends. Ways to test the hypothesis in the future are discusse

ISSN:0020-9309    

DOI:10.1002/iroh.3510680612

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY