Species Richness Values Research Articles

Impacts of roads and trails on floral diversity and structure of Ganga-Choti forest in Kashmir Himalayas

Roads and trails bring deteriorating changes in the structure and composition of forests. The present study investigated the impact of roads and trails on floral diversity and structure of Ganga Choti forest, Kashmir. Phytosociological attributes using systematic quadrate sampling were recorded and analyzed using multivariate ordination techniques including Principal Component Analysis and Cluster Analysis. The total number of species found in the area was 101 belonging to 47 plant families. The dominant family was Poaceae followed by Labiateae, Asteraceae and Rosaceae. The dominant species of the area included Pinus wallichiana, Abies pindrow, Viburnum grandiflorum, Sarcococca saligna, Poa alpina, Fragaria nubicola, Onychium japonicum and Poa pratensis. The dominant life form was Hemicryptophyte (31.68 %), whereas leaf spectra class was Microphyll (30.69 %). The average diversity value was 3.39 with a maximum of 3.71 at the control site and 3.08 at the disturbed site. Average tree density was 505/ha with a maximum of 680/ha at the control site and a minimum of 330/ha at the disturbed site. Intense deforestation was indicated by a stump density value of 330/ha. Results revealed that roads and trails have adversely affected the composition and structure of vegetation with high pressure on keystone tree species. Disturbed sites showed lower values of diversity indices, species richness and regeneration synchronized with high deforestation, overgrazing, erosion and increased frequency of invasive species. The study area needs immediate attention of the management for conservation of local forests by minimizing the impacts of roads and trails.

Insect faunal succession studies on pork carrion in Punjab, India

An insect faunal Succession study on pork carrion was carried out in rural area of district Ludhiana, Punjab, India. Four decomposition stages viz., Fresh, Bloated, Decay and Dry stage were recognized during this experiment. They were separated by taking into account the occurrence and abundance of the specific groups of insects collected from pork as well as condition of pork carrion viz., dehydration, disintegration, flaccidity and desiccation. Fresh stage is recorded with the highest value of species richness and abundance. A total of eighteen species belonging to three orders and ten families were recorded. Diptera, Coleoptera and Hymenoptera were dominating insect fauna on the pork carrion. Four species of Calliphoridae, one of Sarcophagidae, three of Muscidae and one of Anthomyidae were recorded on pork. Five Coleopteran families i.e. Histeridae, Dermestidae, Tenebrionidae, Staphylinidae, Nitidulidae and two species belonging to family Formicidae (Hymenoptera) were also observed.

MULTIVARIATE IMPACT ANALYSIS OF PARTHENIUM HYSTEROPHORUS INVASION ON ABOVE-GROUND PLANT DIVERSITY IN POTHWAR REGION OF PAKISTAN

Phytosociological studies help to understand extent of biological invasion. Multiple analyses of ecological parameters at different locations derive general explanations of impact on species diversity in plant communities. Current study assessed the impact of Parthenium hysterophorus (an annual weed of great significance in Pakistan and worldwide) invasion on native vegetation in Pothwar region of Pakistan. The approach used for the study was random samplings with two categorical factors: invaded and non-invaded under same habitat conditions. Differences in number of species (S), abundance (N), species richness (R), evenness (J'), Shannon diversity index (H') and Simpson index of dominance (lambda) were compared between invaded and control plots by t-test series. Control plots harbored by average of 0.9 more species per 10 m(2). The control category was more diverse (H' = 1.73) than invaded category (H' = 1.53). The higher value of species richness in control plots shows the heterogeneous nature of communities and vice versa in invaded plots. The lower value of index of dominance in invaded plots shows less sample diversity than in the control ones. At multivariate scale, ordination (nMDS) and ANOSIM showed significant magnitude of differences between invaded and control plots in all sites. The most effected site by Parthenium invasion was Jhelum followed by Attock, Rawalpindi, Chakwal and Islamabad. The decrease in diversity indices in invaded over control sites indicated less productive plant communities due to Parthenium invasion. This makes Parthenium a candidate of consideration for appropriate control measures.

Diversity of Green Seaweeds along the Coast of Karachi

The seasonal diversity and species richness of marine benthic green algae or seaweeds belonging to the phylum Chlorophyta found at Karachi coast were studied in present study. At Karachi coast the green seaweeds occupy a large area and show great variation in their types and species composition. Total 48 green species of seaweeds belong to 9 genera 7 families 6 orders and 2 classes were collected from intertidal areas of Karachi coast (Buleji, Manora, Hawks Bay, Sandspit, Korangi Creek, Cape Monze, Paradise Point, Pacha and Rehri) during January 2009 to December 2009. Total 500 individuals examined, representing 9 genera i.e., Enteromorpha, Ulva, Chaetomorpha, Bryopsis, Codium, Caulerpa, Halimeda, Udotea, Valoniopsis. From the present observation it is clear that Buleji and Manora are the more productive sites as compared to other sites. There was great variation in number of species in different genus. All these forty eight studied species were found attached and in epilithic condition. There is much monthly variation found in species richness at Karachi coast during study period. The present study showed that the high values of species richness and abundance of seaweeds were observed during winter season (December to February).

Biodiversity assessment in Western Mediterranean marine protected areas (MPAs): Porifera of Posidonia oceanica meadows (Asinara Island MPA) and marine caves (Capo Caccia–Isola Piana MPA) of Sardinia

This paper focuses on a faunistic inventory and the biogeographic pattern of Sardinian Porifera in a scarcely investigated Italian sea belonging to the Eastern Algero-Provençal Basin. The composition and structure of sponge fauna were studied in two priority habitats in two Marine Protected Areas (MPAs) of the North-Western Sardinian Sea. Shallow-water surveys investigated Posidonia oceanica meadows at five sites in the Asinara Island MPA and three karstic submerged caves in the Capo Caccia–Isola Piana MPA. The annotated checklist shows notably high values of taxonomic richness, confirming that P. oceanica meadows and karstic caves are key habitats for Porifera assemblages. Indeed, the sponge taxa recorded (n = 77) with 59 cave-dwelling and 45 taxa in seagrass meadows represent over 10% of the total Mediterranean sponge fauna, despite the small areas investigated, restricted biotopes and low sampling effort. This suggests that species richness is underestimated in circum-Sardinia seas. Internationally protected species (n = 6), rare species (n = 5) and Mediterranean endemic species (n = 14) were recorded. Previously investigated Posidonia meadows and caves share comparable values of species richness and endemicity with the Sardinian biotopes. The geographic range of species indicates that the biogeographic affinity of the NW Sardinian Sea sponge fauna is dominated by Atlanto-Mediterranean species. The three caves harbour a notably homogeneous sponge community, as indicated by the ca. 50% of shared species and high similarity index (> 83%). By contrast, the composition varies markedly among the five Posidonia meadows, which share only five species and display similarity values ranging ca. 20–60%. Unexpectedly when comparing these contrasting biotopes, faunal similarity is relatively low (< 40% shared species); indeed, Posidonia meadows harbour a notable number of cave-dwelling species in intermatte shaded microhabitats.

Variation in the species richness of parasitoid wasps (Ichneumonidae: Pimplinae and Rhyssinae) across sites on different continents

Abstract The old idea that parasitoid wasps (Ichneumonidae) show an inverse latitudinal diversity gradient has recently been challenged, but how ichneumonid species richness varies across the globe is still not well understood. We carried out field inventories in 21 sites on three continents to clarify this question, focusing on the subfamilies Pimplinae and Rhyssinae. Our total sampling effort was 628 Malaise trap months and the total catch exceeded 65 000 individuals. Our main focus was in two intensively inventoried areas in Amazonia, together yielding 257 Malaise trap months and 26 390 ichneumonid individuals. To expand the scope and assess global species diversity patterns of the Pimplinae and Rhyssinae, we compiled published species lists from a total of 97 study localities around the world. The highest observed species richness in any locality, 105 species, was found in one of our field sites in Peruvian Amazonia. None of the other localities reported more than 70 species, even the ones with a sampling effort comparable to ours. Despite the local thoroughness of our field inventories in Amazonia, data analyses indicated that a substantial proportion of the parasitoid wasp species occurring in each site remained unobserved. The highest local species richness values were reported from the tropics. Nevertheless parasitoid wasps are still too sparsely sampled to draw solid conclusions about whether or not their species richness follows a particular latitudinal trend, and if so, where their richness peaks.

Spatial Patterns of Species Diversity and Phylogenetic Structure of Plant Communities in the Tianshan Mountains, Arid Central Asia.

The Tianshan Mountains, located in arid Central Asia, have a humid climate and are biodiversity hotspots. Here, we aimed to clarify whether the pattern of species diversity and the phylogenetic structure of plant communities is affected by environmental variables and glacial refugia. In this study, plant community assemblies of 17 research sites with a total of 35 sample plots were investigated at the grassland/woodland boundaries on the Tianshan Mountains. Community phylogeny of these plant communities was constructed based on two plant DNA barcode regions. The indices of phylogenetic diversity and phylogenetic community structure were calculated for these sample plots. We first estimated the correlation coefficients between species richness (SR) and environmental variables as well as the presence of glacial refugia. We then mapped the significant values of indices of community phylogeny (PD, RPD, NRI, and NTI) to investigate the correlation between community phylogeny and environmental structure or macrozones in the study area. The results showed that a significantly higher value of SR was obtained for the refugial groups than for the colonizing groups (P < 0.05); presence of refugia and environmental variables were highly correlated to the pattern of variation in SR. Indices of community phylogeny were not significantly different between refugial and colonizing regions. Comparison with the humid western part showed that plant communities in the arid eastern part of the Tianshan Mountains tended to display more significant phylogenetic overdispersion. The variation tendency of the PhyloSor index showed that the increase in macro-geographical and environmental distance did not influence obvious phylogenetic dissimilarities between different sample plots. In conclusion, glacial refugia and environmental factors profoundly influenced the pattern of SR, but community phylogenetic structure was not affected by glacial refugia among different plant communities on the Tianshan Mountains. This pattern of community phylogenetic structure could have resulted from shared ancestry and species pool among these sample plots.

Phytoplankton community in the last undammed stretch of the Paraná River: considerations on the distance from the dam

Abstract Aim: To evaluate the influence of upstream reservoirs on the temporal and spatial variation of the phytoplankton community in the Paraná River channel and the importance of its main tributaries in reducing the oligotrophication process along this stretch of the river. Materials and Methods Sampling of phytoplankton and physical and chemical variables was performed quarterly between August 2013 and May 2015, in the Paraná River main channel and in the mouth of the main tributaries, at the stretch located between downstream Porto Primavera reservoir and the backwaters of Itaipu reservoir. To summarize the variation of phytoplankton density in relation to the main physical and chemical variables, we performed a Redundancy Analysis (RDA). Results A total of 214 taxa were identified throughout the study. We registered low values of phytoplankton species richness and abundance, which showed no patterns of temporal and spatial distribution, both for the Paraná River and the tributaries. However, RDA results showed spatial segregation among samples from the Paraná River main channel, such that the stretch located closer to the dam was associated with higher values of water transparency and Cyanobacteria density, exported by upstream reservoirs, whereas the middle and lower stretches were associated with higher phytoplankton complexity and higher nutrient concentration and turbidity. Conclusion Through the analysis of the phytoplankton community we could verify a reduction in the effects of oligotrophication along the longitudinal axis of the Paraná River and the important role of the tributaries in diminishing this effect.

Influence of tributaries on the periphytic diatom community in a floodplain

Abstract In impacted floodplains, small tributaries have an essential role in the maintenance of ecosystem biodiversity. Aim: We aimed to characterise the periphytic diatom community (Bacillariophyta) in a protected area at the Upper Paraná River floodplain considering the importance of tributaries as a source of propagules. The purpose of this study was to understand the influence of the tributaries in the periphytic diatom community (Bacillariophyta) in a protected area at the Upper Paraná River floodplain. We expect that species present in the main river channel (mainly in the last stretch) would be a subset of the community present in the tributaries. Methods The study area is located in the last non-dammed stretch of the Paraná River in this floodplain, with the contribution of several tributaries. Sampling was performed in 2014 in two tributaries and three sites at the Paraná River main channel, and the periphytic material was obtained from petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth. Results We identified 115 diatom taxa. Higher values of species richness were registered in the tributaries, and higher densities in the tributaries and at sampling sites under the direct influence of the tributaries. We also observed a higher similarity between the tributaries, which are located in the preserved side of the floodplain. The results of beta diversity showed that closer sites had lower values, and that the species turnover was the component more important in this floodplain. Conclusion In this way, these results reinforce the importance of tributaries mainly on the algae establishment and development reflected in the density of species. It demonstrates that sites in preserved area present a higher species richness and can serve as a pool of propagules for downstream environments.

Contrasting arthropod communities associated with dwarf mistletoes Arceuthobium globosum and A. vaginatum and their host Pinus hartwegii

Arthropod communities and epiphytic plants associated with tree canopies have been widely studied and have revealed a great diversity of organisms; however, the community hosted by parasitic plants, such as dwarf mistletoes, remains poorly known. In the coniferous forests of North America, dwarf mistletoe infection (Arceuthobium spp.) significantly damages the health of the forest, causing large financial losses for the forest industry, but it also positively affects diversity, especially of mammals and birds. This study examined the attributes of the arthropod communities associated with two species of dwarf mistletoe [Arceuthobium globosum Hawksw. & Wiens and A. vaginatum (Humb. & Bonpl. ex Willd.) J. Presl] and their host Pinus hartwegii Lindl. In 2010, in five sites located in Zoquiapan (Central Mexico), we collected plant tissue from the three species bimonthly. Arthropods were separated from the plant tissue and identified to the finest level possible. We collected 32,059 individuals, for which 51 morphospecies were identified, belonging to 15 taxonomic orders; the most abundant orders for the three plants were Prostigmata, Thysanoptera and Homoptera. The community associated with P. hartwegii had the highest value of diversity (H′ = 1.47; A. globosum, H′ = 0.64; A. vaginatum, H′ = 0.68) and species richness (S = 40; A. globosum, S = 30; A. vaginatum, S = 35); while abundance was significantly higher for the mistletoes (A. globosum, n = 407 individuals/sample; A. vaginatum, n = 536 individuals/sample; P. hartwegii, n = 134 individuals/sample). Species richness, abundance and diversity were significantly different for the three studied plants, as well for sampling month and the interaction of these two factors (except for diversity). The results suggest that the canopy of P. hartwegii is an important element in the ecosystem, providing a mosaic of resources and conditions to the associated fauna. We also propose that mistletoes are key species within the forest canopy, as they greatly influence the establishment of diverse organisms, particularly arthropods.

Estimating species pools for a single ecological assemblage

BackgroundThe species pool concept was formulated over the past several decades and has since played an important role in explaining multi-scale ecological patterns. Previous statistical methods were developed to identify species pools based on broad-scale species range maps or community similarity computed from data collected from many areas. No statistical method is available for estimating species pools for a single local community (sampling area size may be very small as ≤ 1 km2). In this study, based on limited local abundance information, we developed a simple method to estimate the area size and richness of a species pool for a local ecological community. The method involves two steps. In the first step, parameters from a truncated negative trinomial model characterizing the distributional aggregation of all species (i.e., non-random species distribution) in the local community were estimated. In the second step, we assume that the unseen species in the local community are most likely the rare species, only found in the remaining part of the species pool, and vice versa, if the remaining portion of the pool was surveyed and was contrasted with the sampled area. Therefore, we can estimate the area size of the pool, as long as an abundance threshold for defining rare species is given. Since the size of the pool is dependent on the rarity threshold, to unanimously determine the pool size, we developed an optimal method to delineate the rarity threshold based on the balance of the changing rates of species absence probabilities in the sampled and unsampled areas of the pool.ResultsFor a 50 ha (0.5 km2) forest plot in the Barro Colorado Island of central Panama, our model predicted that the local, if not regional, species pool for the 0.5 km2 forest plot was nearly the entire island. Accordingly, tree species richness in this pool was estimated as around 360. When the sampling size was smaller, the upper bound of the 95% confidence interval could reach 418, which was very close to the flora record of tree richness for the island. A numerical test further demonstrated the power and reliability of the proposed method, as the true values of area size and species richness for the hypothetical species pool have been well covered by the 95% confidence intervals of the true values.ConclusionsOur method fills the knowledge gap on estimating species pools for a single local ecological assemblage with little information. The method is statistically robust and independent of sampling size, as proved by both empirical and numerical tests.

Does Altitude Effect on Species Composition and Diversity on Himalayan Rangeland?

Himalayan rangelands have diverse floristic composition and important ecological services. The floristic diversity and composition play an important role in grassland ecosystem regulation. It is different in altitudinal gradient due to grazing intensity, climatic condition and topography. To reveal the vegetation composition values, this work was conducted on August and September 2011 in Tinjure-Milke mountain ridge, Guphapokhari, Nepal. In the present study we have described the impact of altitude on the species richness, species diversity and dispersion behavior of different plants (grasses) in Himalayan rangeland. The values of community indices were observed to be: RD (0.09 to 49.57), RF (3.57 to 14.71), RA (0.23 to 47.59), IVI (3.89 to 111.87), Shannan-Wiener diversity index (1.09 to 2.23) and species diversity evenness (0.12 to 0.19) at the study area, MilkeJaljale, eastern Nepal. Similarly, Species richness (R) value of 8.87 to 11.86 and Simpson dominant index value of 0.12 to 0.42 were observed. All diversity indices were reversed to altitudinal gradient higher the altitudes lower the values. Species richness of all plants showed a unimodal relationship with altitude. Similarly, negative correlation of density and species richness with altitude and slope was recorded.

Changes of species composition of the Poa pratensis-Festuca rubra plant communities in drainage peatland

AbstractThe objective of this study was to examine the vegetation cover and describe the floristic diversity of selected plant communities of extensive and abandoned grasslands within the Forest of Parczew PLB060006 – a Natura 2000 protected area. Floristic surveys were conducted in the meadows in years 2001 and 2013 under the conditions of natural succession of the communities Poa pratensis-Festuca rubra. The area is situated in the northern part of the Lublin Voivodeship, in the physiographic mesoregion the Łęczna-Włodawa Lakeland. Those communities were characterized by average species richness and floristic diversity index values. The cover index decreased considerably in the case of 8 species, and increased for 12 species. A large increase in the cover index of Holcus lanatus, Deschampsia caespitosa, Galium mollugo, Anthriscus sylvestris and Polemonium caeruleae is particularly noteworthy. In 2001, 39 species of plants were recorded in all relevés, compared to 41 species recorded in 2013. Over 12 years, 11 species disappeared, but 13 new ones emerged. For the time being, the average species richness N increased from 12 to 16 per relevé. The biodiversity index H' increased from 2.8 to 3.6.

Community distance sampling models allowing for imperfect detection and temporary emigration

AbstractRecent developments of community abundance models (CAMs) enable us to analyze communities subject to imperfect detection. However, existing CAMs assume spatial closure, that is, that individuals are always present in the sampling plots, which is often violated in field surveys. Violation of this assumption, such as in the presence of spatial temporary emigration, can lead to the underestimates of detection probability and overestimates of population densities and diversity metrics. Here, we propose a model that simultaneously accommodates both temporary emigration and imperfect detection by integrating CAMs and a form of hierarchical distance sampling for open populations. Expected values of species richness are obtained via the summation of occupancy (or incidence) probabilities, based on species‐level densities, across all species of the community. Simulations were used to examine the effects of spatial temporary emigration on the estimation of biological communities. We also applied the proposed model to empirical data and constructed area‐based rarefaction curves accounting for temporary emigration. Simulation experiments showed that temporary emigration can decrease the local species richness (α diversity) based on densities and increase the species turnover (β diversity). Raw species counts can overestimate or underestimate α diversity in the presence of temporary emigration, but the specific biases depend on the values of detection and emigration probabilities. Our newly proposed model yielded unbiased estimates of α, β, and γ diversity in the presence of temporary emigration. The application to empirical data suggested that accounting for temporary emigration lowered area‐based rarefaction curves because availability probabilities of individual species were estimated to be &lt;1. Temporary emigration prevails in field surveys and has broad significance for understanding the ecology and function of biological communities and separation of imperfect detection and temporary emigration resolves long‐standing issues in the use of count data. We therefore suggest that the consideration of temporary emigration would contribute to understanding the nature and role of biological communities.

Comparative palynology of Macrotermes sp. mounds and Vespula vulgaris nests on the University of Lagos campus, Akoka: preliminary study

AbstractIn order to assess the environmental indicator potential of wasp nests and termite mounds, the palynomorph content of three randomly selectedMacrotermessp. mounds (termitaria) and twoVespula vulgarisnests collected on the University of Lagos campus were examined. Palynological analysis showed the presence of 298 well-preserved palynomorphs showing characteristic morphological features. The recovered palynomorphs included pollen, pteridophyte spores and fungal spores, along with insect parts (106), diatoms (7) and a protist (1). The pollen assemblage of termite mounds comprised 78 pollen and pteridophyte spores, with Poaceae and Arecaceae pollen as dominants. In the wasp nest the pollen assemblage comprised 28 pollen and spore taxa, with Poaceae and Arecaceae pollen also dominant. Both mounds and nests had, besides diatoms, six pollen and spore taxa: Poaceae, Amaranthaceae, Pteridophyte spores, Arecaceae,Raffiasp. andRhizophorasp. Vegetational grouping of the recovered pollen and spores indicated five phytoecological groups: secondary forest, mangrove swamp forest, freshwater, open vegetation and Poaceae. In statistical analyses, termite mounds had a higher species richness value (2.08 as compared to 1.99 from the wasp nests), while the wasp nests had a higher species diversity value (0.997 as compared to 0.845 from the termite mounds). Pollen analyses of the termite mounds and wasp nests suggest that both could be useful tools in environmental studies. This is the first attempt to evaluate the potential of termite mounds and wasps nest as natural pollen accumulators in Nigeria. The results suggest new possibilities for the use of the pollen records preserved in termite mounds and wasp nests for environmental studies.

Suprabenthic assemblages from the Capbreton area (SE Bay of Biscay). Faunal recovery after a canyon turbidity disturbance

In the Capbreton area, suprabenthic assemblages were sampled with a sledge towed over the bottom, at different sites located within the upper part of a ‘gouf-type’ canyon (8 hauls between 642m and 797m, on the axis of the thalweg or on flat perched flank terraces such as site K), on the northern adjacent open slope (2 hauls between 500 and 567m) and on the northern adjacent shelf margin (2 hauls between 151m and 158m). A multivariate analysis carried on the faunal data discriminated different assemblages in this area: a near-canyon shelf assemblage (55 species, mainly amphipods and decapods; 3496 ind./100m2, 40% mysids; dominant species: Nyctiphanes couchii, Leptomysis gracilis, Weswoodilla rectirostris, Anchialina agilis, Scopelocheirus hopei and Philocheras bispinosus); an open slope assemblage (111 species, mainly amphipods and isopods; 249 ind./100m2, 36% amphipods; dominant species: Disconectes phalangium, Munnopsurus atlanticus and Boreomysis arctica); a canyon E assemblage (129 species, mainly amphipods, mysids and cumaceans; 1172 ind./100m2, 58% amphipods; dominant species: Melphidippa sp. B, Chelator insignis); a canyon E’ assemblage (107 species, mainly amphipods and mysids; 507 ind./100m2, 73% amphipods; dominant species: Cleonardopsis carinata, Bonnierella abyssorum, Rhachotropis caeca and Arcturopsis giardi); and a temporary canyon assemblage at site K (34 species, mainly amphipods and mysids; 899 ind./100m2, 85% amphipods; dominant species: Tmetomyx similis, Caeconyx caeculus, Nebalia sp. A and Cleonardopsis carinata). Site K was sampled only four months after a turbidity event, detected on sediment cores (18cm thick Bouma sequence) taken during the same cruise and triggered by the violent storm (‘ouragan Martin’, wind up to 200km/h) which affected the French Atlantic coast on 27 December 1999. The corresponding suprabenthic assemblage showed evidence of deep structural changes after this catastrophic event, characterized by relative low values of species richness and diversity indices and by the exceptional dominance of opportunistic pioneer colonizers such as the scavenger Tmetonyx similis (61% of total density). Partial assemblage recovery was noticed 18 months after the turbidite deposition, attested by higher values of structural indices and by the inclusion of the corresponding sample within the climax canyon assemblage cluster.

Temporal variation and structure of macro-epifauna associated with macrophytes in the Bizerte lagoon (Tunisia, SW Mediterranean Sea)

ABSTRACTThe temporal variation in composition and abundance of the macro-epifauna associated with seaweeds (Ulva lactuca, Cladophora sp., Gracilariopsis longissima and Gracilaria bursa-pastoris) and seagrass (Cymodocea nodosa) was investigated at Menzel Jemil station in the Bizerte lagoon. Twelve replicate samples (25 x 25 cm frame) were collected monthly from October 2009 to September 2010. Sampling data yielded 21,575 invertebrate specimens from floating seaweeds and the seagrass, belonging to 40 taxa, of which 18 species were arthropods, 13 molluscs, three echinoderms, three fishes, two polychaetes and one cnidarian. Crustaceans were the most dominant and the most species-rich group and Idotea balthica basteri the most abundant species, accounting for 28.94% of the total abundance. Minimum (9.25 ± 5.56 species) and maximum (19.75 ± 3.2 species) values of mean species richness were observed in December and June, respectively. Species richness and density of macro-epifauna showed similar trends to plant biomass and the highest values of both indices coincided with periods of maximal plant biomass. Mean values of Shannon’s index H′ and evenness J′ were low, ranging from 0.34 ± 0.02 bit to 1.08 ± 0.06 bit, and from 0.23 ± 0.03 to 0.52 ± 0.07, respectively. The high dominance of herbivores and detritivores highlighted the substantial role played by macrophytes as food source for associated macro-epifauna species. Multivariate analyses also indicated significant seasonal differences for the macro-epifauna assemblage and revealed significant relationships with environmental variables. According to the canonical correspondence analysis, concentrations of phosphates and nitrites, and temperature were the variables that explained the variation of the macro-epifauna abundance in the Bizerte lagoon.

Helminth parasitizing &lt;em&gt;Iberolacerta cyreni&lt;/em&gt; (Müller et Hellmich, 1937) from Gredos Mountains, Iberian Peninsula

A survey of the helminth communities of a population of Iberolacerta cyreni (Müller et Hellmich, 1937), a small lizard endemic to Sistema Central (Iberian Peninsula), was conducted to determine the prevalence, abundance and species diversity of parasites of these reptiles. Four species of helminths were found, one trematode, Plagiorchis molini Lent et Freitas, 1940, one cestode, Nematotaenia tarentolae López-Neyra, 1944, and two nematodes, Skrjabinelazia sp. and Spauligodon carbonelli Roca &amp; García-Adell, 1988. Helminth infracommunities of I. cireny showed very low values of abundance and species richness and diversity, being similar to other European lizards. The parasites found seem to have no influence on the conservation status of the host species in its natural habitat&#x0D; .

Variations in the community structure of biofilm-dwelling protozoa at different depths in coastal waters of the Yellow Sea, northern China

Biofilm-dwelling protozoa are a primary component of microbiota and play important roles in the functioning of microbial food webs such as the mediation of carbon and energy flux from plankton to benthos in marine ecosystems. To demonstrate the vertical pattern of the protozoan communities, a 1-month baseline survey was carried out in coastal waters of the Yellow Sea, northern China. A total of 40 samples were collected using glass slides as artificial substrates at four depths: 1, 2, 3.5 and 5 m. A total of 50 species were identified, comprising seven dominant and eight commonly distributed species. Species richness and individual species abundances showed a clear decreasing trend down the water column from 1 to 5 m, although the former peaked at a depth of 2 m. Multivariate approaches revealed that protozoan community structure differed significantly among the four depths, except for those at 2 and 3.5 m. Maximum values of species richness, diversity and evenness generally decreased with depth although they peaked at either 2 or 3.5 m. These results suggest that water depth may significantly shape the community patterns of biofilm-dwelling protozoa in marine ecosystems.

Statistical mapping and 3-D surface plots in phytoplankton analysis of the Balkhash Lake (Kazakhstan)

Abstract Phytoplankton of the Balkhash Lake was represented by 91 species with average abundance of 1,002.4 mln. ind. m−3 and average biomass of 0.853 g m−3 in summer 2004. Maps of spatial distribution revealed that phytoplankton abundance was confined within the near-estuary sections of the rivers. Correlation analysis and 3D Surface Plots showed that the average mass of the algal cell decreased with increased phytoplankton abundance, species richness, and Shannon Bi index values. Synchronicity of the spatial dynamics of W-Clarke and Δ-Shannon values evidenced the possibility of obtaining information on the structure of communities by both calculated and graphical methods.