摘要:

Abstract.Both the emergent surfaces and tide pools of the rocky intertidal shores of the Bay of Morbihan, Kerguelen are depauperate in number of macroinvertebrate and macroalgal species. Diversity (H') was high and similar for macroinvertebrates in tide pools from the high to low intertidal and on the emergent surface exposed at extreme low‐tide when calculated in terms of numbers of individuals. H' was lower when calculated in terms of energy and twice as high for the tide pool in the high intertidal than the lower tide‐pools and the emergent surface. H' for macroalgae was 0 in the highest tide‐pool and highest in the lower tide‐pools. The density/species‐rank curves for the macroinvertebrates and the macroalgae are logarithmic but vary in linearity. Algal biomass was 37 % of the macroinvertebrate biomass on the emergent surface at the extreme low‐tide, but 106% in the highest tide‐pool. Twenty‐three months after denudation of the tide pools, the ratios of total densities of the macroinvertebrates (ind m‐2) to the original densities were 48 % for the pool in the high intertidal, 25 % for the middle tide‐pool, and 4 % for the pool in the low intertidal. The diversity indexes for the macroinvertebrates were similar to the original ones. Recolonization at Kerguelen is slow and shows an intertidal gradient. The composition of the rocky intertidal community at Kerguelen results from the rigorous physical environment and the small number and functional types of species. In the absence of major predators on macroinvertebrates and of herbivores on macroalgae, interaction among the species present seems to be co

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1987.tb00184.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract.The interdependences between phytoplankton standing crop, bacterial biomass and the dissolved organic matter (DOM) pool in the water column were investigated and related to sediment parameters in a shallow marine bay (Bay of Piran, Northern Adriatic Sea) over an annual cycle. Bacterioplankton density varied between 1–10 × 105cells ml‐1, with lowest density observed in March corresponding to the low Chiaconcentrations during this period. Generation times as determined by dialysis incubations ranged between 4h (June) and 82 h (March). Mean bacterial secondary production rates during summer were about 40 mg C m‐1d‐1and 5mg C m‐3.d‐1during winter. With a short time lag, DOM concentrations followed the fluctuation in Chia.Sediment oxygen demand measurements revealed a mean mineralization rate of about 260 mg C m‐2d‐1during summer and 100–200 mg C m‐2d‐1in winter. Sediment bacterial density varied between 108‐ 109cells g (sediment dry wt)‐1in the top 5 cm sediment layer or, in terms of biomass, 4.3 g C m‐lduring summer and 0.6 g C m‐2during winter. Highest concentrations of DOM in pore waters were measured in September, coinciding with high r

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1987.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract.Vertical profiles of temperature, nutrients (silicate, phosphate, and nitrate), chlorophyllaand phytoplankton abundance are given for six stations located in the Gulf of California, June 1982, above 1 % of light intensity. The vertical distribution of phytoplankton was related to the water column structure: stratified stations had a defined nutricline and subsurface chlorophyll and phytoplankton abundance maxima were present, which were found to be related to the depth of the principal thermocline; vertical distribution of taxa was not uniform and low affinity values (<0.5) were calculated among depths at these stations. Despite the irregular vertical distribution of chlorophyll and cell number, there was a great affinity in the species composition throughout the euphotic zone at well‐mixed or weakly stratified stations. Nanoplankton organisms, mainly coc‐colithophorids, were the most important numerical contributors at the chlorophyll maxima, except when this was superficial, in which case diatoms were the most numerous group. Some patterns of the vertical distribution of the main phytoplankton groups (e.g., diatoms, dinoflagellates, and microflagellates) are shown. The spectrum of diversity in the water column was useful only for mixed‐waters. The relationship between stability, nutrients, and phytoplankton ‐ regarding their vertical distribution ‐ and the importance of physical and biological processes on phytoplankton ecology are

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1987.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract.A tentative method is developed to determine the assimilative surface and the total and active photosynthetic volume in caespitose algal communities. The estimation of these variables and the analysis of photosynthetic pigments allow the description of structural adaptive responses in relation to light reception in two morphotypes ofCorallina elongata, i. e., those growing in sunny and shaded intertidal localities.A cross transplantation of both morphotypes demonstrates that one type rapidly converts to the other. This indicates an adaptivity of morphology and pigment composition.The results presented in this work as well as the comparison between intertidal and terrestrial communities suggest that both have a similar potential efficiency in harvesting the incident radiation, but that the degree of compactation of the photosynthetic apparatus (Leaf Area Index) is different.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1987.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Abstract.A Mediterranean fish assemblage has been visually censused over a period of two years from two permanent, rocky, infralittoral stations (10–15 m) which display a high habitat complexity and are located in a protected area. Six home‐range categories were defined for a better understanding of the community structure which was analyzed through qualitative and quantitative data. The respective roles of different sources of variability in species composition and numerical abundance were evalua

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1987.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY