Fish Assemblage and Abundance Distribution in Nanji Islands Marine Nature Reserve in Relation to Season Change

The fishing survey station located in the warm waters of the East China Sea is one of the abundant fishery resources of waters;with a large number of economic fish breeding grounds and economic juvenile feeding grounds. Several fish species according to this bottom trawl survey results which appear in the annual survey from winter to autumn give us a total of 58 species, which have appeared throughout the year. But the vast majority of species appears only in certain seasons, according to the sea fish survey and based on seasonal migratory species or species mainly small endemic species. The survey of fish is tropical and subtropical warm water species and warm temperate species, and the history of the area has several types of 397 different species. There are many reasons, in addition to recent years, human disturbance and adverse consequences of environmental changes brought about, but also with the relevant sampling methods and sampler time, the survey sampled only trawl based, from Ping yang Ocean and Fisheries Bureau, the waters are still other jobs method net, gill nets, fishing industry, etc. Survey results show that the type of fish in the summer (58 species) > spring (55 species) > winter (51 species) > autumn (42 species). The type of season was among spring to summer rose, summer to autumn decline. The survey found that in the reef area of the Nanji Islands, no one species of fish is the dominant species throughout the year (according to the dominant species, each species is dominant only in one season). From the dominant species turnover accounting for the four seasons, in winter it has 53.72% of the total biomass or annual biomass, spring it has 41.53% of the overall biomass, summer it has 31.85% and autumn it has 38.56% of total biomass. Visible, seasonal succession of dominant species of fish phenomenon is very obvious, especially in the spring and winter, summer transfers dominate species at this stage show the greatest change, but winter, the transfer of this dominant species changes in minimal. Seasonal changes from biomass and the average annual marine fish survey biomass were 4832.25 g/h. From different seasons, the average biomass in winter (10779.88 g/h) > of the average biomass in spring (3624.1 g/hour) > of the mean biomass in autumn (3158 g/h) > the average Biomass in summer (1767 g/h). All of them show significant seasonal variation of the biomass, in winter and spring, the biomass is generally not high, but significantly higher than in the summer and autumn seasons. Each season, around the coast of southern Zhejiang, is less than the biomass and other catches off, which involves investigating sea location, size range, and the survey ship different network related tools. Another change from the area of biomass, some studies found that the survey of four-season fish of waters above the biological capacity of several kilograms only in some stations, namely stations and the highest biomass in summer appeared in stations 3, 7 and 11. In autumn the highest biomass appeared in stations 3, 6, 20 and 23.

Species abundance distribution models of Toona ciliata communities in Hubei Province,China

The study of plant species abundance distribution(SAD)in natural communities is of considerable importance to understand the processes and ecological rules of community assembly.With the distribution of tree,shrub and herb layers of eight natural communities of Toona ciliata as research targets,three diff erent ecological niche models were used:broken stick model,overlapping niche model and niche preemption model,as well as three statistical models:log-series distribution model,log-normal distribution model and Weibull distribution model,to fi t SAD of the diff erent vegetation layers based on data collected.Goodness-of-fi t was compared with Chi square test,Kolmogorov–Smirnov(K–S)test and Akaike Information Criterion(AIC).The results show:(1)based on the criteria of the lowest AIC value,Chi square value and K–S value with no signifi cant diff erence(p>0.05)between theoretic and observed SADs.The suitability and goodness-of-fi t of the broken stick model was the best of three ecological niche models.The log-series distribution model did not accept the fi tted results of most vegetation layers and had the lowest goodness-of-fi t.The Weibull distribution model had the best goodness-of-fi t for SADs.Overall,the statistical SADs performed better than the ecological ones.(2)T.ciliata was the dominant species in all the communities;species richness and diversity of herbs were the highest of the vegetation layers,while the diversities of the tree layers were slightly higher than the shrub layers;there were fewer common species and more rare species in the eight communities.The herb layers had the highest community evenness,followed by the shrub and the tree layers.Due to the complexity and habitat diversity of the diff erent T.ciliata communities,comprehensive analyses of a variety of SADs and tests for optimal models together with management,are practical steps to enhance understanding of ecological processes and mechanisms of T.ciliata communities,to detect disturbances,and to facilitate biodiversity and species conservation.

Species Diversity and Abundance Distribution of Pelagic Siphonophores in Nan Wan Bay of Taiwan, China, in Late Autumn and Early Winter

Zooplankton surveys were carried out on November 2-3 and December 8-10, 2001 at 12 stations in the Nan Wan Bay of Taiwan, China. Altogether 92 quantitative zooplankton samples were collected from subsurface water and bottom water layers with two conical plankton nets （180 cm in length, 45 cm in opening diameter, 333μm and 200 larn in mesh size）. A total of 31 species of Siphonophores were identified, among them 7 species are new records in the waters around Taiwan Island, of which Rocacea cymbiformis is a new record in China. Dominated by Chelophyes appendiculata, Bassia bassensis, Diphyes bojani, Diphyes dispar, Abylopsis eschscholtzi and Chelophyes contorta, these species accounted for over 76 % and 63 % of the total abundance in November and December. The species number and Siphonophores abundance in December （25 species, 1.99 inds/m3） were more than those in November （19 species, 0.438 inds/m3）, and they were more in the surface water layer than in the bottom layer at most sampling stations. In early winter, the offshore high salinity water mass was a main factor influencing the distribution. The sampling efficiency for two plankton nets is discussed and the seasonal variation of species number and abundance in the Nan Wan Bay is compared with that in the neighboring waters.

Diversity, Abundance and Distribution Patterns of Epibenthic Echinoderms in Dungonab Bay, Red Sea, Sudan

The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square metre belt transects along each permanent line transect at 20 metre intervals were used to collect data. The data were subjected to univariate and multivariate analyses. Spatial variations of epibenthic echinoderm abundance were assessed with one-way analysis of variance. Hierarchical agglomerative clustering was used to identify and illustrate the similarities in echinoderm abundance between line transects and between belt transects. Indices of richness (d), diversity (H'), evenness (J') and dominance (C) were used to explain the diversity of epibenthic echinoderm species. The distribution pattern of each echinoderm species was determined in each permanent line transect. A total of 986 individuals were recorded within sixteen species of epibenthic echinoderms in the four line transects. Holothuriidae was the dominant family (5 species and 342 individuals). The most abundant echinoderms species was Pearsonothuria graeffei (77 individuals, about 7.81%). Abundances intra-transects and intra-families were insignificant (f = 1.67, p = 0.183, df = 3 and f = 3.24, p = 0.083, df = 9, respectively). The highest values of Shannon-Wiener diversity index (H'), Pielou evenness index (J'), Margalef species richness index (d), and Simpson Dominance index (C) were 2.738, 0.9875, 2.791 and 0.07159, respectively. The distribution patterns of all species in the study transects varied between clumped and uniform, with the exception of Asthenosoma varium of the Echinothuridae family, which had clumped distribution patterns in all transects. The study concluded that Dungonab Bay supports rich and diverse communities of epibenthic echinoderms.

Evaluating the Impacts of Human Activities on Diversity, Abundance, and Distribution of Large Mammals in Nimule National Park, South Sudan

Globally, human activities have a significant impact on the diversity, abundance, and distribution of large mammals in Protected Areas (PAs). These disturbances increase human pressure on biodiversity and species habitats, highlighting the need for conservation. This study aimed to assess the abundance and distribution of large mammals in different habitat types within Nimule National Park (NNP) and understand the impacts of human activities on them. Data on the abundance and distribution of large mammals and their respective habitat types were collected through line transect surveys. Human activity signs were observed and recorded along the transect lines. To estimate the impacts of human activities on the diversity, abundance, and distribution of large mammal species, as well as to identify any significant differences between them and their habitat types, the study utilized the Kruskal Wallis test, Polynomial multiple regressions, and diversity indices. The findings from the Shannon-Weiner and Simpson indices indicated that large mammal species were more diverse inside the park (H’ = 1.136;D = 0.570) compared to the buffer zone (H’ = 0.413;D = 0.171), with 85% (443 out of 510 samples) recorded within Nimule National Park. The species abundance showed a semi-balanced status (0.58). The diversity results among different habitat types revealed that large mammals were more diverse and highly distributed in both open woodlands (244) and dense woodlands (192), while riverine vegetation had the lowest diversity (8). Statistical tests demonstrated a highly significant difference at a 99% confidence interval (p-value = 0.01) between habitat types and identified species of large mammals. Additionally, the results highlighted the high abundance of Uganda kob (274), baboons (141), and warthog (57) across most habitat types, accounting for at least 75% of their distribution. The most prevalent human activities observed were cattle footprints (27%) and cattle dung (14%). Human footprints and tree cutting combined accounted for 9%, indicating the practice of livestock grazing, poaching, encroachment, and fuelwood collection by local communities. However, these activities did not appear to significantly impact the diversity, abundance, and distribution of large mammals in Nimule National Park. Therefore, it is crucial to foster shared responsibilities and engage relevant stakeholders in the management and conservation of large wildlife species. Regular community awareness programs should be implemented to cultivate a sense of ownership. Moreover, it is recommended that a comprehensive survey be conducted on the population status of all mammal species in Nimule National Park, including its surrounding Buffer Zone. Monitoring the impact of human activities on their behavior and habitats using satellite images should also be carried out at least every five to ten years.

High-throughput metabarcoding of SAR11 assemblages from the southwest Atlantic shelf and arid Patagonia:richness and associated rank abundance distributions

Background:Massively parallel sequencing of environmental DNA allows microbiological studies to be performed in greater detail than was possible with first-generation sequencing.For example,it facilitates the use of approaches hitherto largely applied to flora and fauna,such as rank abundance distribution(RAD)analyses.Methods:Here,we set out to advance the knowledge on Ca.Pelagibacterales(SAR11)communities from southern South America using environmental sequences from the open ocean in the Argentine sea,the uncharted Engaño Bay,as well as a river and an oligohaline shallow lake from the Patagonian Steppe ecoregion.The structures of the SAR11 assemblages present in these ecosystems were dissected by direct and rarefaction-based estimates of species richness,and evaluations of the corresponding abundance distributions(ADs),which was addressed by RAD analyses.Results:Microbial community composition analyses revealed that the studied SAR11 assemblages coexist with 27 bacterial phyla.SAR11 richness was in general very high,but ADs turned out to be highly uneven.The results were compatible with prior knowledge,and similar to that derived from point estimates of diversity.However,our comprehensive dissection allowed for more detailed quantitative comparisons to be made between the environments surveyed,and revealed differences regarding both richness and the underlying ADs.Conclusions:Despite SAR11 assemblages being extremely rich,their ADs are very uneven.Richness and ADs can vary,not only between fresh and salt water,but also between oceanic and coastal marine environments.The obtained results provide insights on general topics such as adaptation and the contrast between marine and freshwater radiations.

Species Abundance Distribution Patterns of a Toona ciliata Community in Xingdoushan Nature Reserve

With the goal of model fitting species abundance distribution patterns of the tree,shrub and herb layers of the natural Toona ciliata community in Xingdoushan Nature Reserve,Enshi Autonomous Prefecture,Hubei Province,we used the data collected from the field survey and employed different ecological niche models.The models tested were the broken stick model(BSM),the overlapping niche model(ONM)and the niche preemption model(NPM),as well as three statistic models,the log-series distribution model(LSD),the log-normal distribution model(LND)and the Weibull distribution model(WDM).To determine the fitted model most suitable to each layer,the fitting effects were judged by criteria of the lowest value of Akaike Information Criterion(AIC),Chi-square and the K-S values with no significant difference(P>0.05)between the theoretical predictions and observed species abundance distribution values.The result showed:(1)The fitting suitability and goodness of fit of the tree,shrub and herb layers by using the three ecological niche models were ranked as:NPM>BSM>ONM.Of the three statistical models,by accepting the fitting results of the three layers,WDM was the best fitting model,followed by LND.By rejecting the fitting tests of the herb layer,LSD had the worst fitting effect.The goodness of the statistical models was ranked as:WDM>LND>LSD.In general,the statistical models had better fitting results than the ecological models.(2)T.ciliata was the dominant species of the tree layer.The species richness and diversity of the herb layer were much higher than those of either the tree layer or the shrub layer.The species richness and diversity of the shrub layer were slightly higher than those of the tree layer.The community evenness accorded to the following order:herb>shrub>tree.Considering the fitting results of the different layers,different ecological niche models or statistical models with optimal goodness of fit and ecological significance can be given priority to in studying the species abundance distribution patterns of T.ciliata communities.

SPECIES-AREA RELATIONSHIP FOR POWER-LAW SPECIES ABUNDANCE DISTRIBUTION

We studied the mathematical relations between species abundance distributions （SADs） and species-area relationships （SARs） and found that a power-law SAR can be generally derived from a power-law SAD without a special assumption such as the ＂canonical hypothesis＂. In the present analysis, an SAR-exponent is obtained as a function of an SAD-exponent for a finite number of species. We also studied the inverse problem, from SARs to SADs, and found that a power-SAD can be derived from a power-SAR under the condition that the functional form of the corresponding SAD is invariant for changes in the number of species. We also discuss general relationships among lognormal SADs, the broken-stick model （exponential SADs）, linear SARs and logarithmic SARs. These results suggest the existence of a common mechanism for SADs and SARs, which could prove a useful tool for theoretical and experimental studies on biodiversity and species coexistence.

Seasonal abundance and distribution of pelagic tunicates (Chordata: Thaliacea) in the central South China Sea

A total of 168 macro-zooplankton samples from 42 stations in the central South China Sea （12° ～20° N, 111°～118°E, an area of about 64 × 10^4 km^2 ） were collected in September 1983 （autumn） , April 1984 （spring） , August 1984 （summer） and December 1984 （winter）. Twenty-three species and subspecies of tunicates were found, of which Thalia democratica complex （including T. d. orientalis and T. d. echinata） and Doliolum denticulatum were the dominant species, and accounted for 95.7% , 90. 0%, 91.8% and 90. 5% of the total tunicates found in autumn, winter, spring and summer, respectively. The highest abundance （with a mean of 2.37 ind./m^3 ） occurred in autumn. There are strong correlations between the abundances of the tunicates and those of phytoplankton and chlorophyll a concentration. However, tunicates also aggregate in areas with low primary production in the autumn survey, probably due to the water circulation pattern.

Synchronous Variations in Abundance and Distribution of Ommastrephes bartramii and Dosidicus gigas in the Pacific Ocean

An analysis was performed in this study to investigate synchronous fluctuations in abundance and distribution of Om-mastrephes bartramii in the Northwest Pacific Ocean and Dosidicus gigas in the Southeast Pacific Ocean.The impacts of two Niño indices and regional water surface temperature on the two squids during 2006-2015 were evaluated,which possibly can explain the observed synchronicity.Catch per unit effort(CPUE)and the latitudinal gravity centers(LATG)of fishing effort were used to indi-cate squid abundance and distribution,respectively.The results indicated that both the CPUE and LATG showed highly interannual variations and synchronous fluctuation with significant negative associations between the two squid species from September to No-vember.Strong positive cross-correlations with 2-month lag was found between sea surface temperature(SST)anomaly in the Niño 3.4 and Niño 1+2 regions,which have significant linkage with the SST on the fishing ground of O.bartramii and D.gigas,respec-tively.Moreover,the proportion of favorable-SST area(PFSST)and the latitudinal location of the optimal SST for O.bartramii and D.gigas were positively correlated with the CPUE and LATG,respectively.Increased O.bartramii PFSST clearly corresponded to decreased D.gigas PFSST in phase as well as the latitudinal location of the optimal SST from September to November over 2006-2015.Our findings suggest that synchronous changes in abundance and distribution of the two squids were due to simultaneous variations in the PFSST and the latitudinal location of the optimal SST front which were affected by the SSTA changes in the Niño 3.4 and Niño 1+2 regions.

Ecological characteristics of the abundance and distribution of bacteria in the waters nearby the front of the Hangzhou Bay

Abundance of total bacteria, heterotrophic bacteria, coliform and oil degradable bacteria and their relations with salinity and suspended matter in the frontal waters in the Hangzhou Bay are described. The results obtained show that the highest abundances of total bacteria , heterotrophic bacteria are encountered around the front and near the northern shore of the Hangzhou Bay, where a positive correlation ( r =0. 70) between the total bacteria abundance and the total suspended matter (TSM) is persent. Moreover,the abundance of oil degradable bacteria being an indicator of oil pollution, is also high in that region.

Distribution pattern of pelagic amphipods and its affecting facors in the East China Sea

On the basis of data from four seasonal cruises in the East China Sea （23°30′-33°N, 118°30′-128°E） from 1997 to 2000, horizontal distribution of amphipods, seasonal variations of abundance and their dynamic mechanisms were approached with quantitative and qualitative methods. Results showed that the average value of amphipod abundance in autumn was 115× 10^-2 ind./m^3, the highest in four seasons. The second occurred in summer with a mean value of 44×10^-2 ind./m^3and the lowest occurred in spring with a mean of 10 × 10^-2 ind./m^3. Amphipods were hardly observed in the north nearshore （ 29° 30′- 33° N and 122°30′- 125°E） in winter and spring. In all seasons, except for the north of the sea in autumn and the south in summer, the abundance in the offshore area was higher than that nearshore. The major species influencing the amphipod abundance were Lestrigonus schizogeneios in spring, L. macrophthalmus and L schizogeneios in summer,L bengalensis and Hyperioides sibaginis in autumn and Gammarus sp. in winter. The amphiped abundance showed a prominent linear correlation with the surface water temperature, but no significant correlation with both other water temperatures and salinity in spring. It was found that water temperature and salinity were not significantly correlated with the variation of amphiped abundance in summer, autumn and winter. In addition, the amphiped abundance in all four seasons can be linearly correlated with the bottom water temperature. The highest abundance area was located in the mixture waters near the side of warm water current in summer. Peak of amphiped abundance in autumn, not in summer told a temporal process for amphipeds to develop their populations. The continuance of warm current was beneficial to the development of amphipod abundance from summer to autumn. Amphipeds are kinds of very important diets for fishes in the offshore East China Sea.

Study on abundance variation of pteropods in the East China Sea

On the basis of the census in four seasons from 1997 to 2000 in the East China Sea （23°30＇-33°N, 118°0＇-128°E）, the horizontal distribution of pteropods, the seasonal variations of their abundance and dynamic mechanisms of these variations were approached with quantitative and qualitative methods. Results showed that the total abundance of pteropods varied clearly with the seasons in an order of decrease of autumn （108×10-2 ind./m^3）, summer （33×10^-2 ind./m^3）, winter（28×10^-2 ind./m^3） and spring （10×10^-2 ind./m^3）. Pteropods were not observed in the north nearshore of the East China Sea （29°30＇-33°N, 122°30＇-125°E）in winter and spring. In all seasons, the peteropod abundance was higher in the south than that in the north and higher in the offshore than that in the nearshore. The major species influencing the peteropod abundance were Creseis acicula in spring, Creseis virgula in summer, Desmopterus papilio in autumn and Limaeina trochiforrnis in winter. The variation of pteropod abundance showed a prominent linear correlation with the surface water temperature and 10 m water temperature, but no significant correlation with both the bottom water temperature and salinity. In summer, the high-abundance distribution area of pteropods was located in the place where the Taiwan Warm Current branched from the Kuroshio. Inautumn, thedistribution area with anabundance higher than 250×10^-2ind/m^3expanded northward along with the Taiwan Warm Current within the mixing area where the Changjiang freshwater, the Fujian-Zhejiang coastal water and the Huanghai Sea Cold Water met together. Water temperature and warm currents were the most important environmental factors that influenced the changes ofpteropod abundance in the East China Sea.

Relationship between Abundance and Area of Pinus tabulaeformis and Quercus liaotungensis Koidz in Lingkong Mountain Nature Reserve

The spatial distribution and species abundance of Pinus tabulaeformis and Quercus liaotungensis Koidz were analyzed with random distribution abundance model and aggregated distribution abundance model,and evaluation goodness was evaluated based on related information of sample area at 4 hm2 in Shanxi Lingkong Mountain with altitude at 1500-1 800 m.The results showed that of the 30 xylophyta plants,abundance of 20 plants was increasing in sequence and the covered spaces extended accordingly,except of 10 plant species.As pixel area extended,curve of abundance-area tended to be volatile if area in abundance sequence was smaller than that of the front one;the curve tended to be stable if the fluctuating point was removed.For the same species,the higher pixel area is,the larger the covered area of the species in corresponding pixel would be.The results of evaluation goodness indicated that aggregated distribution model is better for prediction on relationship between abundance and area,compared with random distribution abundance model.Both of the two models rely on value of m,namely,number of covered pixel given the pixel is fixed.For the species distribute dispersedly,the prediction results would be more accurate if both of the two models are made use of,or the prediction errors would be larger.Given that the total area of sample plot is fixed,the smaller the pixel area is,the more accurate the prediction would be.

Community structure of picoplankton abundance and biomass in the southern Huanghai Sea during the spring and autumn of 2006

During spring and autumn of 2006, the investigations on abundance, carbon biomass and distri- bution of picoplankton were carried out in the southern Huanghai Sea （Yellow Sea, sHS）. Three groups of picoplankton-Synechococcus （Syn）, Picoeukaryotes （PEuk） and heterotrophic bacteria （BAC） were identified, but Prochlorococcus （Pro） was undetected. The average abundance of Syn and PEuk was lower in spring （5.0 and 1.3×10^3 cells/cm^3, respectively） than in autumn （92.4 and 2.7×0^3 cells/cm^3, respectively）, but it was opposite for BAC （1.3 and 0.7×10^6 cells/cm^3 in spring and autumn, respectively）. And the total carbon biomass of picoplankton was higher in spring （37.23×11.67） mg/m^3 than in autumn （21.29×13.75） mg/m^3. The ratios of the three cell abundance were 5：1：1 341 and 30：1：124 in spring and autumn, respectively. And the ratios of carbon biomass of them were 5：7：362 and 9：4：4 in spring and autumn, respectively. Seasonal distribution characteristics of Syn, PEuk, BAC were quite different from each other. In spring, Syn abundance decreased in turn in the central waters （where phytoplankton bloom in spring occurred）, the southern waters and inshore waters of the Shandong Peninsula （where even Syn was undetected）; the high values of PEuk abundance appeared in the central and southern waters and the inshore of the Shandong Peninsula; the abundance of BAC was nearly three order of magnitude higher than that of photosynthetic picoplankton, and high values appeared in the central waters. In autumn, Syn abundance in central waters was higher than that in surrounding waters, while for PEuk abundance, it decreased in turn in the inshore waters of the Shandong Peninsula, the southern waters and the central waters; BAC presented a complicated blocky type distribution. Sub-surface maximum of each group of picopalnkton appeared in both spring and autumn. Compared with the available lit- eratures concerning the studied area, the range of Syn abundance was larger, and the abundance of BAC was higher. In addition, the conversion factors for calculating picoplanktonic carbon biomass were discussed, with the conversion factors which are different from previous studies in the same surveyed waters. The result of regression analysis showed that there was distinct positive correlation between BAC and photosynthetic picoplankton in spring （r=0.61, P 〈0.001）, but no correlation was found in autumn.

Pedodiversity: A Case Study Based on 1:1 Million Scale SOTER of Shandong Province, China

The diversity of soils derived from different parent materials and developed on different terrains inShandong Province, China, was analyzed with the theory of pedodiversity using a 1:1000000 scale soilsand terrain digital database (SOTER) of Shandong Province in a geographical information system (GIS)environment. Diversity index of soils derived from different parent materials followed the sequence of igneousrock ＞ sedimentary rock ＞ metamorphic rock ＞ unconsolidated material. Diversity index of soils developedon different terrains followed the sequence of plain ＞ medium-gradient mountain ＞ medium-gradient hill＞ valley floor ＞ medium-gradient escarpment zone ＞ depression ＞ high-gradient mountain. Abundancedistributions of these soil groups matched the logarithmic normal distributions.

Species Abundance in a Forest Community in South China：A Case of Poisson Lognormal Distribution

: Case studies on Poisson lognormal distribution of species abundance have been rare, especially in forest communities. We propose a numerical method to fit the Poisson lognormal to the species abundance data at an evergreen mixed forest in the Dinghushan Biosphere Reserve, South China. Plants in the tree, shrub and herb layers in 25 quadrats of 20 m× 20 m, 5 m× 5 m, and 1 m× 1 m were surveyed. Results indicated that: (i) for each layer, the observed species abundance with a similarly small median, mode, and a variance larger than the mean was reverse J-shaped and followed well the zero-truncated Poisson lognormal; (ii) the coefficient of variation, skewness and kurtosis of abundance, and two Poisson lognormal parameters (& and μ) for shrub layer were closer to those for the herb layer than those for the tree layer; and (iii) from the tree to the shrub to the herb layer, the α and the coefficient of variation decreased, whereas diversity increased. We suggest that: (i) the species abundance distributions in the three layers reflects the overall community characteristics; (ii) the Poisson lognormal can describe the species abundance distribution in diverse communities with a few abundant species but many rare species; and (iii) 1/α should be an alternative measure of diversity.

Characteristics of the microzooplankton community in Jiaozhou Bay,Qingdao,China

The species composition and abundance of microzooplankton at 10 marine and five coastal stations （Hongdao, Daguhe, Haibohe, Huangdao and Hangxiao） in the Jiaozhou Bay （Qingdao, China） were studied in 2001. The microzooplankton community was found to be dominated by Tintinnopsis beroidea, Tintinnopsis urnula, Tintinnopsis brevicoUis and Codonellopsis sp. The average abundance of microzooplankton was highly variable among stations. Specifically, the abundance of microzooplankton was higher at inshore stations and lower in the center of the bay （St. 5）, bay mouth （St. 9） and outside the bay （St. 10）. The highest average annual densities （346 ind./L） was observed at St. 3, while the lowest （55 ind./L） was at St. 10. Two abundance peaks were recorded in May （324 ind./L） and February （300 ind./L）. The distribution of microzooplankton in three sampling layers at the 10 stations was relatively homogenous and the abundance decreased slightly as the water depth increased. At coastal stations, the highest average annual density was recorded at Hongdao Station （677 ind./L）, followed by Daguhe Station （616 ind./L）, Haibohe Station （400 ind./L ）, Huangdao Station （275 ind./L） and Hangxiao Station （73 ind./L）. Furthermore, a 24-h sampling analysis conducted at Hangxiao Station revealed that the microzooplankton assemblages were characterized by a bimodal diel vertical migration pattem, with the highest densities occurring at dusk （154 ind./L）, followed by dawn （146 ind./L）, noon （93 ind./L） and midnight （77 ind./L）. The density of microzooplankton in the Jiaozhou Bay was in the middle range of the densities of temperate coastal waters worldwide.

Plant diversity and community structure of Brazilian Páramos

In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We aimed to evaluate the patterns of biodiversity and structure of plant communities from rocky outcrops in high altitude grasslands of three areas at the Caparaó National Park, southeastern Brazil, by sampling 300 randomly distributed plots. Then, we compared the floristic composition, relative abundance, and biological and vegetation spectra among areas. We classified species as endemic and non-endemic and verified the occurrence of endangered species. Species richness was evaluated by rarefaction analysis on the sampling units. The importance value and species abundance distribution(SAD) models were assessed. We also performed an indicator species analysis. We sampled 58 species belonging to 49 genera and 32 families. The number of species decreased with increasing altitude, with significant differences being observed among areas regarding richness, abundance, and cover. Of the total number of species, 10 are endemic to the Caparaó National Park and 17 are listed on the Brazilian Red List of endangered species. The dominant families on all peaks were Asteraceae and Poaceae. The SAD models showed lognormal and geometric distributions, corroborating the fact that 10 species that were common to all three areas were also the most dominant ones in the communities and showed the highest importance values, which ranged between 35% and 60%. Indicator species analysis revealed that 28 species(48.27%) were indicators. Of these, 42.85% had maximum specificity, meaning that they occurred only in one area. Thus, the number of species per life form ratio was similar among areas, yet vegetation spectra differed, especially for hemicryptophytes. The altimetric difference among the areas showed to be a very important driver in the community assembly, influencing the evaluated variables, however, other drivers as soil depth, slope and water could also influence the community structure on a smaller and local spatial scale.

Changes in Tintinnid Assemblages from Subantarctic Zone to Antarctic Zone Along Transect in Amundsen Sea(West Antarctica) in Early Austral Autumn

Tintinnid ciliates are important pelagic microplankton.Most studies previously conducted in the Amundsen Sea have covered a relatively small latitude range and provided minimal information about tintinnid species composition and distribution.The present study was conducted to investigate tintinnid assemblages from the Antarctic zone(AZ)northward through the polar front(PF)to the subantarctic zone(SAZ).A total of 17 tintinnid species belonging to seven genera were collected,and 16 were identified.Results show that nine of the species are endemic to the Southern Ocean and they mainly inhabit the AZ near Antarctic continent with an abundant proportion exceeding 60%of total tintinnid.According to the tintinnid abundance distribution,the species were divided into four groups:Group I includes Acanthostomella norvegica,Codonellopsis glacialis,C.pusilla and Cymatocylis antarctica and mainly occurs in the northern boundary of the PF;Group II includes Cymatocylis convallaria forma calyciformis,an unidentified species,and Amphorellopsis quinquealata and mainly inhabits the PF;Group III includes Salpingella costata,Cymatocylis vanhoeffeni,C.convallaria forma cristallina,C.convallaria forma drygalskii,C.convallaria,Codonellopsis gaussi,and Laackmanniella naviculaefera and mainly occurs in the AZ near the Antarctic continent;and Group IV,which comprises Salpingella sp.and inhabits all zones.The new species of tintinnid(belonging to Group II)primarily inhabit the AZ but also are distributed in the PF,and they have large lorica-oral-diameter(LOD).The distribution ranges of tintinnid assemblages from the AZ to PF were determined,in addition to the different assemblages mixed in the PF.The information provided in this study increases our understanding of tintinnid assemblages from the Antarctic continent in the Antarctic Circumpolar Current and Antarctic waters.