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1.
Copepod community ingestion rates of Calanus finmarchicus, Temora longicornis, Acartia longiremis and Pseudocalanus spp., and egg production rates of C. finmarchicus and T. longicornis, were studied in relation to phytoplankton composition, abundance and biomass on the Faroe shelf during a one-year cycle.
The phytoplankton community during winter was mainly composed of small flagellates and the copepods of Pseudocalanus spp. As the spring bloom progressed, diatoms increased in abundance and dominated the biomass throughout summer. C. finmarchicus increased in numbers in early spring, while T. longicornis and A. longiremis dominated the community during summer and autumn. While no response in ingestion rates was observed for A. longiremis and Pseudocalanus spp. with increasing diatom biomass, both ingestion rates and egg production of C. finmarchicus and T. longicornis, generally increased, showing a dependence upon diatoms for production. The daily ingestion for C. finmarchicus females was 7% and 22% of body biomass during the pre-bloom and bloom period, respectively, while for T. longicornis females it was 33% and 56% and for A. longiremis females 22% and 33%, respectively. C. finmarchicus accounted for more than 80% of the total copepod ingestion in May, but in mid- and late summer, T. longicornis and A. longiremis dominated, and represented 80–90% of the total copepod ingestion. The proportion of reproductively mature C. finmarchicus increased as the phytoplankton biomass increased. Most of the time there was good agreement between herbivorous ingestion
rates and calculated carbon demand for the observed egg production. However, both species showed a peak in egg production
prior to the phytoplankton spring-bloom.
Handling editor: J. Padisak. 相似文献
2.
URSULA GAEDKE MIRIAM RUHENSTROTH‐BAUER INA WIEGAND KATRIN TIROK NICOLE ABERLE PETRA BREITHAUPT KATHRIN LENGFELLNER JULIA WOHLERS ULRICH SOMMER 《Global Change Biology》2010,16(3):1122-1136
To improve our mechanistic understanding and predictive capacities with respect to climate change effects on the spring phytoplankton bloom in temperate marine systems, we used a process‐driven dynamical model to disentangle the impact of potentially relevant factors which are often correlated in the field. The model was based on comprehensive indoor mesocosm experiments run at four temperature and three light regimes. It was driven by time‐series of water temperature and irradiance, considered edible and less edible phytoplankton separately, and accounted for density‐dependent grazing losses. It successfully reproduced the observed dynamics of well edible phytoplankton in the different temperature and light treatments. Four major factors influenced spring phytoplankton dynamics: temperature, light (cloudiness), grazing, and the success of overwintering phyto‐ and zooplankton providing the starting biomasses for spring growth. Our study predicts that increasing cloudiness as anticipated for warmer winters for the Baltic Sea region will retard phytoplankton net growth and reduce peak heights. Light had a strong direct effect in contrast to temperature. However, edible phytoplankton was indirectly strongly temperature‐sensitive via grazing which was already important in early spring at moderately high algal biomasses and counter‐intuitively provoked lower and later algal peaks at higher temperatures. Initial phyto‐ and zooplankton composition and biomass also had a strong effect on spring algal dynamics indicating a memory effect via the broadly under‐sampled overwintering plankton community. Unexpectedly, increased initial phytoplankton biomass did not necessarily lead to earlier or higher spring blooms since the effect was counteracted by subsequently enhanced grazing. Increasing temperature will likely exhibit complex indirect effects via changes in overwintering phytoplankton and grazer biomasses and current grazing pressure. Additionally, effects on the phytoplankton composition due to the species‐specific susceptibility to grazing are expected. Hence, we need to consider not only direct but also indirect effects, e.g. biotic interactions, when addressing climate change impacts. 相似文献
3.
Markus von Scheibner Petra Dörge Antje Biermann Ulrich Sommer Hans‐Georg Hoppe Klaus Jürgens 《Environmental microbiology》2014,16(3):718-733
Global warming is assumed to alter the trophic interactions and carbon flow patterns of aquatic food webs. The impact of temperature on phyto‐bacterioplankton coupling and bacterial community composition (BCC) was the focus of the present study, in which an indoor mesocosm experiment with natural plankton communities from the western Baltic Sea was conducted. A 6°C increase in water temperature resulted, as predicted, in tighter coupling between the diatom‐dominated phytoplankton and heterotrophic bacteria, accompanied by a strong increase in carbon flow into bacterioplankton during the phytoplankton bloom phase. Suppressed bacterial development at cold in situ temperatures probably reflected lowered bacterial production and grazing by protists, as the latter were less affected by low temperatures. BCC was strongly influenced by the phytoplankton bloom stage and to a lesser extent by temperature. Under both temperature regimes, Gammaproteobacteria clearly dominated during the phytoplankton peak, with Glaciecola sp. as the single most abundant taxon. However, warming induced the appearance of additional bacterial taxa belonging to Betaproteobacteria and Bacteroidetes. Our results show that warming during an early phytoplankton bloom causes a shift towards a more heterotrophic system, with the appearance of new bacterial taxa suggesting a potential for utilization of a broader substrate spectrum. 相似文献
4.
S. V. Aleksandrov N. N. Zhigalova A. S. Zezera 《Russian Journal of Marine Biology》2009,35(4):296-304
Long-term research in the Baltic Sea revealed the basic trends of zooplankton community variations depending on oceanographic
processes. Alternation of the periods of increase and decrease in salinity of the Baltic Sea against the background of climate
changes (temperature increase) and eutrophication affect the state of the entire Baltic ecosystem, including zooplankton.
For these periods, the dynamics of zooplankton in the Baltic Sea were analyzed based on literature data and results of regular
research in the southeastern Baltic Sea during 1998–2007. The changes in the hydrological situation were accompanied by significant
changes in the zooplankton community. In the 1990s–2000s, the abundance and biomass of brackish-water and thermophilous species
primarily of Cladocera and Copepoda increased markedly. The role of the previously dominant marine copepod Pseudocalanus elongatus decreased due to salinity reduction in the deep-water part of the Baltic Sea. Maximum development of zooplankton occurred
in years of the greatest warming-up of the water (2001, 2005–2007) against the background of a general positive trend of zooplankton
abundance in the last decade. 相似文献
5.
Are copepods important grazers of the spring phytoplankton bloom in the western Irish Sea? 总被引:3,自引:0,他引:3
Gowen R; McCullough G; Kleppel G; Houchin L; Elliott P 《Journal of plankton research》1999,21(3):465-483
The spring phytoplankton bloom and copepod grazing were studied at a
coastal and offshore station in the western Irish Sea during 1997. Maximum
chlorophyll standing stocks of 132.8 mg m-2 inshore
and 199.4 mg m-2 offshore were measured in late
April. At that time, mean water column temperatures were 10 and 8C at the coastal and offshore station, respectively.
Spring bloom production at the coastal station was estimated as 31.2 g C
m-2 and was dominated by the diatom
Guinardia delicatula. Offshore, production was 28.2 g
C m-2 and the bloom was composed of small (10 m) phytoflagellates
and the silicoflagellate Dictyocha speculum. Maximum
copepod abundance (189 and 544 x 103 individuals
m-2, inshore and offshore, respectively) coincided
with the spring bloom. Pseudocalanus and
Temora ingestion rates were derived from measurements
of gut pigment fluorescence, and were found to vary during the course of
the spring bloom as a result of changes in gut content. Grazing by late
copepodite and adult Pseudocalanus and
Temora was variable inshore, but overall accounted for
17% of bloom production. Offshore, 22% of bloom production was grazed with
maximum grazing (76% of daily production) occurring at the end of the
bloom. Large copepod species were not major grazers of the spring bloom.
Greater utilization of spring bloom production by copepods in the western
Irish Sea compared to regions of the North Sea is attributed to differences
in population size at the time of the bloom.
相似文献
6.
Spatio-temporal distribution and production of calanoid copepods in the central Baltic Sea 总被引:3,自引:0,他引:3
Hansen Frank C.; Mollmann Christian; Schutz Ulrike; Neumann Thomas 《Journal of plankton research》2006,28(1):39-54
The aim of our study was the exploration of species-specificdistribution and production patterns of dominant copepods inthe Central Baltic Sea (Bornholm Basin). Spatio-temporal distribution,egg and secondary production were studied by means of net-samplingand egg production experiments from April to August 1999. Verticaland horizontal distribution patterns appeared to be linked witheach other and were primarily species-dependent. Both Acartiaspp. and Temora longicornis preferentially inhabited the upper30 m of the water column and the shallower marginal regionsof the Bornholm Basin. In contrast, the C45 and C6 ofPseudocalanus spp. preferentially inhabited the halocline region(5070 m) and the deep central part of the area. Observeddifferences in horizontal distribution among these three copepodsappear to result from different depth preferences and depth-dependentwater circulation patterns. Egg production rates (EPR) clearlyexhibited seasonal differences with maximum EPR in May and minimumEPR in July. Mean EPR was significantly different between species,being highest in Acartia spp. and lowest in Pseudocalanus spp.The variability in EPR was related to differences in hydrographyand modelled food environment. 相似文献
7.
The impact of predators on population growth of Pseudocalanussp. was investigated in Dabob Bay, Washington. Mortality ofPseudocalanus sp. was determined from stage-specific survivorship,from seasonal changes in mortality rates of adult males andfemales and from incidence of injuries to adult copepods. Theprincipal predators of adult Pseudocalanus were identified asthe predatory copepod Euchaeta elongata, the omnivorous euphausiidEuphausia pacifica and the chaetognath Sagirta elegans. Predatorattack rates - and prey mortality rates - are highly density-dependentand thus sensitive to prey dispersion in the water column, particularlyto layering in the vertical plane. Predation rates by the threeprincipal predators exceeded 100% of the recruitment rate toadult Pseudocalanus sp. beginning in early summer, thus restrictingpopulation growth. Planktivorous fish predation (by adult three-spinestickleback, Gasterosteus aculeatus, and juvenile chum salmon,Oncorhynchus keta) on Pseudocalanus sp. adults was estimatedto be two orders of magnitude lower than consumption rates bypredatory zooplankton, at a deep water station in July. Analysisof seasonal changes in prey ingested by Sagitta elegans revealedthat Pseudocalanus sp. was the major prey item of S. elegansin April (61.0% of prey) and in June (67.0% of prey), thereafterdeclining seasonally in importance. Predation by S. elegansvaried seasonally with changes in chaetognath stage structure,vertical distribution and diapause, not size structure alone.Although chaetognath recruitment and population growth appearto be directly coupled to the abundance of Pseudocalanus sp.,predation by S. elegans has little reciprocal impact on Pseudocalanussp. population growth; hence asymmetries may occur in the interaction of planktonic prey and predators. 相似文献
8.
The toxic dinoflagellate Alexandrium ostenfeldii is the only bioluminescent bloom-forming phytoplankton in coastal waters of the Baltic Sea. We analysed partial luciferase gene (lcf) sequences and bioluminescence production in Baltic A. ostenfeldii bloom populations to assess the distribution and consistency of the trait in the Baltic Sea, and to evaluate applications for early detection of toxic blooms. Lcf was consistently present in 61 Baltic Sea A. ostenfeldii strains isolated from six separate bloom sites. All Baltic Sea strains except one produced bioluminescence. In contrast, the presence of lcf and the ability to produce bioluminescence did vary among strains from other parts of Europe. In phylogenetic analyses, lcf sequences of Baltic Sea strains clustered separately from North Sea strains, but variation between Baltic Sea strains was not sufficient to distinguish between bloom populations. Clustering of the lcf marker was similar to internal transcribed spacer (ITS) sequences with differences being minor and limited to the lowest hierarchical clusters, indicating a similar rate of evolution of the two genes. In relation to monitoring, the consistent presence of lcf and close coupling of lcf with bioluminescence suggests that bioluminescence can be used to reliably monitor toxic bloom-forming A. ostenfeldii in the Baltic Sea. 相似文献
9.
Hermanni Kaartokallio Jaana Tuomainen Harri Kuosa Jorma Kuparinen Pertti J. Martikainen Kristina Servomaa 《Polar Biology》2008,31(7):783-793
Coastal fast ice and underlying water of the northern Baltic Sea were sampled throughout the entire ice winter from January
to late March in 2002 to study the succession of bacterial biomass, secondary production and community structure. Temperature
gradient gel electrophoresis (TGGE) and sequencing of TGGE fragments were applied in the community structure analysis. Chlorophyll-a and composition of autotrophic and heterotrophic assemblages were also examined. Overall succession of ice organism assemblages
consisted of a low-productive stage, the main algal bloom, and a heterotrophic post-bloom situation, as typical for the study
area. The most important groups of organisms in ice in terms of biomass were dinoflagellates, plasticidic flagellates, rotifers
and ciliates. Ice bacteria showed a specific succession not directly dependent on the overall succession events of ice organisms.
Sequenced 16S rDNA fragments were mainly affiliated to α-, β-, and γ-proteobacterial phyla and Cytophaga–Flavobacterium–Bacteroides-group, and related to sequences from cold environments, also from the Baltic Sea. Temporal clustering of the TGGE fingerprints
was stronger than spatial, although lower ice and underlying water communities always clustered together, pointing to the
importance of ice maturity and ice–water interactions in shaping the bacterial communities. 相似文献
10.
The first occurrence of the ctenophore <Emphasis Type="Italic">Mnemiopsis leidyi</Emphasis> in the North Sea 总被引:1,自引:1,他引:0
Maarten Boersma Arne M. Malzahn Wulf Greve Jamileh Javidpour 《Helgoland Marine Research》2007,61(2):153-155
After the discovery of large densities of Mnemiopsis leidyi in the Baltic Sea near Kiel by Javidpour et al. (First record of Mnemiopsis leidyi A. Agassiz 1865 in the Baltic Sea, 2006) in October 2006, we investigated the gelatinous zooplankton in the North Sea near Helgoland
and recorded Mnemiopsis leidyi for the first time in the North Sea, albeit in much lower densities than those recorded in the Baltic Sea. 相似文献
11.
Abiotic factors influencing cyanobacterial bloom development in the Gulf of Finland (Baltic Sea) 总被引:1,自引:0,他引:1
Blooms of cyanobacteria are a recurrent phenomenon in the Baltic Sea, including the Gulf of Finland. The spatial extension,
duration, intensity and species composition of these blooms varies widely between years. Alg@line data collected regularly
from ferries as well as weather service and marine monitoring data from 1997 to 2005 are analysed to determine the main abiotic
factors influencing the intensity and species composition of cyanobacterial blooms in the Gulf of Finland. It is demonstrated
that the development of the Nodularia spumigena Mertens bloom is highly dependent on weather conditions such as photosynthetically active radiation and water temperature.
Nutrient conditions, especially the surplus of phosphorus (according to Redfield ratio) related to the pre-bloom upwelling
events in the Gulf, affect the intensity of Aphanizomenon sp. (L.) Ralfs blooms. Differences in bloom timing and duration indicate that, if the preconditions (like nutrient ratio/concentration
and weather conditions) for bloom formation are favourable, then the Aphanizomenon bloom starts earlier, the overall bloom period is longer and the Nodularia peak might appear in a wider time window.
Handling editor: K. Martens 相似文献
12.
The cyanobacterial blooms in the Baltic Sea are dominated by diazotrophic cyanobacteria, the potentially toxic species Aphanizomenon sp. and the toxic species Nodularia spumigena. The seasonal succession with peaks of Aphanizomenon sp., followed by peaks of N. spumigena, has been explained by the species-specific niches of the two species. In a three-factorial outdoor experiment, we tested if nutrient and radiation conditions may impact physiological and biochemical responses of N. spumigena and Aphanizomenon sp. in the presence or absence of the other species. The two nutrient treatments were f/2 medium without NO (3) (-) (-N) and f/2 medium without PO (4) (3-) (-P), and the two ambient radiation treatments were photosynthetic active radiation >395?nm (PAR) and PAR + UV-A + UV-B >295?nm. The study showed that Aphanizomenon sp. was not negatively affected by the presence of N. spumigena and that N. spumigena was better adapted to both N and P limitation in interaction with ultraviolet radiation (UVR, 280-400?nm). In the Baltic Sea, these physical conditions are likely to prevail in the surface water during summer. Interestingly, the specific growth rate of N. spumigena was stimulated by the presence of Aphanizomenon sp. We suggest that the seasonal succession, with peaks of Aphanizomenon sp. followed by peaks of N. spumigena, is a result from species-specific preferences of environmental conditions and/or stimulation by Aphanizomenon sp. rather than an allelopathic effect of N. spumigena. The results from our study, together with a predicted stronger stratification due to effects of climate change in the Baltic Sea with increased temperature and increased precipitation and increased UV-B due to ozone losses, reflect a scenario with a continuing future dominance of the toxic N. spumigena. 相似文献
13.
Ecosystem consequences of biodiversity change are often studied from a species loss perspective, while the effects of invasive
species on ecosystem functions are rarely quantified. In this experimental study, we used isotope tracers to measure the incorporation
and burial of carbon and nitrogen from a simulated spring phytoplankton bloom by communities of one to four species of deposit-feeding
macrofauna found in the species-poor Baltic Sea. The recently invading polychaete Marenzelleria
arctia, which has spread throughout the Baltic Sea, grows more rapidly than the native species Monoporeia affinis, Pontoporeia femorata (both amphipods) and Macoma balthica (a bivalve), resulting in higher biomass increase (biomass production) in treatments including the polychaete. Marenzelleria incorporated and buried bloom material at rates similar to the native species. Multi-species treatments generally had higher
isotope incorporation, indicative of utilization of bloom material, than expected from monoculture yields of the respective
species. The mechanism behind this observed over-yielding was mainly niche complementarity in utilization of the bloom input,
and was more evident in communities including the invader. In contrast, multi-species treatments had generally lower biomass
increase than expected. This contrasting pattern suggests that there is little overlap in resource use of freshly deposited
bloom material between Marenzelleria and the native species but it is likely that interference competition acts to dampen resulting community biomass. In conclusion,
an invasive species can enhance incorporation and burial of organic matter from settled phytoplankton blooms, two processes
fundamental for marine productivity. 相似文献
14.
Simultaneous measurements of respiration, excretion and production rates were carried out several times over a year period at five representative stations of the Ebrié Lagoon. Assuming a constant assimilation efficiency rate of 69.4%, we derived metabolic budgets for carbon, nitrogen and phosphorus. Daily specific ingestion rates calculated were rather generally high, and ranged between 54 and 159% of body carbon, between 26 and 102% of body nitrogen and between 108 and 307% of body phosphorus. Regional and seasonal variations depended mainly upon variations in trophic conditions. Curvilinear relationships between ingestion production, or net production efficiency K2, and food concentration (as chlorophyll-a + phaeopigments) showed that food could have been a limiting factor. Furthermore, K2 were low when compared with data from the literature (mean of 21% in carbon, 39% in nitrogen and 11% in phosphorus).Complementary laboratory experiments carried out on adults fed with enriched natural particles or algal cultures (Tetraselmis sp. or Dunaliella sp.) showed similar production (egg-production) vs food concentration curvilinear relationships as in the field. However, considerably higher maximal ingestion and production rates were obtained for animals fed algal cultures suggesting that optima for food acquisition and transformation were not reached in field conditions.Consequently, A. clausi, which represents more than 50% of the zooplankton biomass, appears to be rather inefficient in transforming the abundant particulate organic matter produced in the lagoon. This results from its high level of metabolic expenditure through respiration or excretion (about 50% of ingestion in terms of carbon) and from the small size and poor trophic value of food particles (high percentage of detritus). 相似文献
15.
Lena Seuthe Gérald Darnis Christian Wexels Riser Paul Wassmann Louis Fortier 《Polar Biology》2007,30(4):427-436
Faecal pellet production (FPP) and respiration rates of Calanus glacialis, C. hyperboreus and Metridia longa were measured under land-fast ice in the southeastern Beaufort Sea during the winter–spring transition (March–May 2004) prior
to the phytoplankton spring bloom. Despite different overwintering and life cycle strategies and remaining low concentrations
of suspended chlorophyll a and particulate organic matter, all species showed increasing FPP rates in spring. A corresponding increase in respiration
was only observed in C. glacialis, while respiration remained constant in C. hyperboreus and M. longa. In C. glacialis and C. hyperboreus calculated ingestion covered respiratory expenditures. The constancy of the oil sac volume in M. longa suggests that the animals fed during winter-spring. Pre-bloom grazing as shown here seems to acclimate the copepod populations
physiologically for the upcoming high feeding season, so that they are able to resume maximum grazing and reproduction as
soon as the phytoplankton bloom is initiated. 相似文献
16.
Paula Kankaala 《International Review of Hydrobiology》1987,72(2):121-146
Studies on the zooplankton community of the Bothnian Bay (BB), the northernmost basin of the Baltic Sea, were carried out in 1976–78. Only 8–14 taxa dominated in the zooplankton community. The highest abundances and biomasses occurred during the warmest period or immediately afterwards, in July–September. The production of zooplankton was estimated to be 3.1–7.8 g C · m−2. a−1 in the coastal area and 2.5–3.6 g C · m−2 · a−1 in the open sea. During the short growing season (June–September) the biomass turnover took place in about 11 days. The productivity of zooplankton is discussed in relation to available food of both autochthonous and allochthonous origin and compared with the other parts of the Baltic Sea. 相似文献
17.
We introduce an index for estimating the annual phytoplankton spring bloom intensity in the Baltic Sea. It is based on chlorophyll
a estimates calculated from automatically sampled fluorescence and chlorophyll a measurements on board cargo ships from 1992 to 2004. The intensity is described by an index including information on the
chlorophyll a concentration and duration of the spring bloom period. In all of the years studied, the spring bloom was most intense in
the Gulf of Finland. In the Gulf of Finland and the Northern Baltic Proper there was a slight tendency for the bloom to start
earlier in the spring. 相似文献
18.
Norbert Wasmund 《International Review of Hydrobiology》1997,82(2):169-184
Cyanobacterial blooms occur regularly in summer in central parts of the Baltic Sea. They are mainly composed of Aphanizomenon sp. and Nodularia spumigena. Both species have almost similar ecological requirements and can roughly be considered a uniform functional group. In order to identify factors that might favour bloom development, water quality data from monitoring programmes were compared with bloom distribution. A salinity from 3.8 to 11.5 PSU proved important for the spatial distribution of the bloom development. The bloom's onset was triggered by temperatures approximating 16°C provided that global radiation was > 120 W/m2 (daily mean) and wind speed was < 6 m/s. Nutrient concentrations decreased immediately before the bloom. The bloom's development ceased with poor weather conditions characterized by low irradiation or high wind speed. 相似文献
19.
Temporal and spatial patterns of crustacean zooplankton dynamics in a transitional lagoon ecosystem 总被引:1,自引:0,他引:1
Patterns and mechanisms of plankton crustacean seasonal succession in the eutrophic freshwater Curonian lagoon (south-eastern Baltic Sea) were analysed on the basis of four-year (1995, 1996, 1998 and 1999) field sampling results. The seasonal crustacean zooplankton succession in the lagoon appears to be the consistent six-stage sequence of four distinct species complexes. Each stage is characterised by its individual species composition and quantitative characteristics. The uniform and periodic pattern of the limnetic zooplankton crustacean successional stages in the lagoon indicates that the seasonal succession of the limnetic zooplankton is not disturbed by unpredictable environmental fluctuations, such as brackish water inflows. Seasonal zooplankton succession is also comparatively uniform at a spatial scale. Not more than two adjacent successional stages were found across the northern part of the lagoon during each of 11 seasonal surveys. Comparison between monthly water residence time and dominant plankton crustacean species life cycle duration points to a more transitory plankton community in spring while in the summer it is not much influenced by lagoon hydrodynamics. Consequently, the Curonian lagoon crustacean community quite closely follows the Plankton Ecology Group (PEG)-described freshwater lake seasonal succession in summer and turns into a lentic-like system in spring and autumn. 相似文献
20.
Two species of the calanoid copepod Pseudocalanus, P. acuspes and P. elongatus, have been reported from the Baltic and North Seas. Morphometric analysis based on Frost (Can J Zool 67:525–551, 1989) did not identify the species in samples collected during the German GLOBEC program; the majority of measurements fell outside
reported ranges for Baltic and North Sea specimens. A multiplexed species-specific PCR (SS-PCR) protocol was designed from
a ~700 bp sequence of mitochondrial cytochrome oxidase I (mtCOI), with primers designed to amplify regions of different sizes
for the two species to allow detection by gel electrophoresis. The accuracy and reliability of the multiplexed SS-PCR reaction
was confirmed by sequencing the mtCOI region. Preliminary SS-PCR analysis of geographic distributions of the two species indicated
that P. acuspes occurred exclusively at sampling sites in the Baltic Sea, whereas P. elongatus was found in the southern North Sea and at one site in the Baltic. The SS-PCR protocol can be used for routine identification
of the two species for studies of population, community and ecosystem dynamics. 相似文献