Coefficient Of Community Similarity Research Articles

Microphytobenthos of Water Bodies of Some Islands of the Indian Ocean

Microphytobenthos of water bodies of some Maldivian Islands (Kelaa and Filladho) and the Madagascar Island of the Indian Ocean was studied in autumn (September and November) 1981. As a result of the performed investigations, 43 species of microscopic algae belonging to 30 genera, 25 families, 21 orders, 5 classes, 3 divisions, 2 kingdoms, and 2 empires (domains) were found. Among them, diatoms (38 species) prevailed over Dinoflagellata (4) and Cyanobacteria (1). The Sorensen - Chekanovsky coefficient of community similarity between the Maldivian and Madagascar floras was 0.56 and the Jaccard coefficient of community similarity was 0.36. Microphytobenthos of the investigated water bodies was of marine type. It was represented by alkaliphilous species and cosmopolitan (27 species) and tropical (10) groups with boreal-tropical (4) and boreal-tropical-notal (2) elements.

Changes in Phytoplankton of the Irpin River (Ukraine) as a Result of Military Activities in Its Basin

Phytoplankton structure was studied in a comparative aspect (before and after the beginning of military activities) in the section of the Irpin River belonging to a large lowland rivers flowing in silicate rocks. On the whole, 132 algal species of seven divisions were found in the water column of the Irpin River during the period of investigations. Bacillariophyta and Chlorophyta were highly diverse in their species composition (37.1 and 31.1% of the total number of species). The distribution of plankton algae at the studied stations even within the same massif of surface waters was non-uniform in terms of species composition (the Sorensen coefficient of community similarity on the average was 37%), species richness (18-49 species), cell numbers (1930 thousand cells/L - 24,450 thousand cells/L), and biomass (2.118 mg/L - 20.374 mg/L). Almost different algal species dominated at various stations (14 species among 20 dominated only at one station). Compared to the previous period of investigations (2018), the number of plankton algal species in the studied section of the Irpin River somewhat increased (from 121 to 132). Phytoplankton taxonomic structure also somewhat changed. The contribution of Bacillariophyta increased from 22.3 to 37.1% and that of Cyanoprokaryota - from 9.1 to 12.1%. In this case, the contribution of Chlorophyta decreased from 47.1 to 37.1%. The quantitative indices of phytoplankton development increased. The maximum numbers increased from 19,480 thousand cells/L to 24,450 thousand cells/L, whereas the maximum biomass - from 5.143 mg/L to 20.374 mg/L. As a consequence of the impact of military activities on phytoplankton of the Irpin River, it is possible to consider an increase in the number of its species, the maximum numbers and biomass, as well as the contribution of water bloom forming blue-green algae in the estuarine section of the Irpin River due to the disturbance of hydromorphology and the income of an additional amount of nutrients from flooded territories, which can lead to the formation of such a negative phenomenon as water bloom in this section of the river.

THE ASSOCIATION OF TREE SPECIES DIVERSITY AND ABUNDANCE WITH THE SOIL EDAPHIC FACTOR IN A LARGEST TROPICAL RECREATIONAL FOREST OF TERENGGANU, PENINSULAR MALAYSIA

A study was conducted to investigate the association between tree species composition with soil edaphic factor in Chemerong Recreational Forest, the largest recreational forest in Terengganu, Peninsular Malaysia. Two types of forest were chosen which are riparian forest and inland forest. Four plots with the dimension of 50 m × 20 m each were established with two plots at each forest type with total study site of 0.4 ha. A total of 1158 trees (>1 cm diameter) from 263 species, 125 genus and 50 families were recorded. The higher species number was recorded in the inland forest with 175 species, 103 genus and 45 families compared to riparian plot with 154 species, 109 genera and 39 families. Lijndenia laurina was found to be the important species in the riparian forest with Important Value Index (IVi) of 5.22% while Mangifera caesia at the inland forest with 3.21%. The Shannon-Weiner diversity indexes (H’) was considered high in all two types of forest with 5.04 at the riparian forest and 5.14 at the inland forest. Sorenson’s community similarity coefficient (CCs) showed the tree species communities, between the two types of forest had low similarities with 0.38. A total 33 endemic species in Peninsular Malaysia were found at Chemerong Recreational Forest. Fifty-five species in this study were listed in the International Union for Conservation of Nature IUCN red list of threatened species 2019. Significant differences were found in phosphorus, electric conductivity, ammonium nitrate, moisture content and organic matter between these forests. Canonical Correspondence Analysis (CCA) showed less association between species composition with the physico-chemical characyeristics of soil in this study indicating the soil edaphic factor is not the main factor controlling the species distribution at this site.

Anostracan (Crustacea: Branchiopoda) zoogeography III. Australian bioregions.

Anostracan bioregions were identified for Australia. These regions were quantitatively defined using species distributions compared through Jaccard's Coefficient of Community Similarity, and qualitatively defined using regional soils data. Community assemblages are quantified using Fager's Index of Recurring Species Groups. Substrate geochemistry was used to investigate additional relationships, but was limited by the constraints of available data. However, the highly salinized soils directly relate to Australia bearing the highest diversity of halophilic anostracan taxa. Three anostracan biogeographical regions are defined for Australia: Western, Eastern and Southern.

Anostracan (Crustacea: Branchiopoda) zoogeography I. North American bioregions.

Nine anostracan biogeographical regions are defined for North America: Appalachia/Ozark, Southwest Arid, Great Plains, Coastal Plain, Neotropical, California, Cold Deserts, Beringia/Canadian Shield, and Transmontane. These regions are quantitatively defined using species distributions compared through Jaccard's Coefficient of Community Similarity, and qualitatively defined using climate data, following the ecoregions protocol of the US Environmental Protection Agency for North America and the Universidad Nacional Autónoma de México for Mexico. Community assemblages are quantified using Fager's Index of Recurring Species Groups. The average Fager's Index for each bioregion, as well as the percentage of taxa co-occurring, generally decreases with the length of time the region has been available for colonisation. The strong Fager's Index/colonisation time availability relationship suggests that the Monopolization Hypothesis of De Meester et al. may function at larger landscape scales.

Microbial Diversity and Succession in the Chinese Luzhou-Flavor Liquor Fermenting Cover Lees as Evaluated by SSU rRNA Profiles

The microbial diversity and the community succession in the fermenting cover lees of Chinese Luzhou-flavor liquor were investigated by small-subunit rRNA (SSU rRNA) culture independent method. All sequences retrieved from the 1, 7 and 60days fermented cover lees were respectively assigned into the genera of Streptococcus, Acetobacter, Arthrobacter, Bacillus, Staphylococcus, Serratia, Nocardia, Methanoculleus, Clostridium, Aneurinibacillus, Corynebacterium, Lactobacillus, Microbacterium, Trichosporon, Saccharomycopsis, Sagenomella, Talaromyces, Eurotium, Issatchenkia, Zygosaccharomyces, Saccharomyces and TM7 phylum. The fungal Issatchenkia, Saccharomycopsis and Talaromyces and the bacteria Staphylococcus and Lactobacillus were most abundant in the 1day fermented cover lees, the fungal Issatchenkia, Saccharomyces and Talaromyces and the bacteria Bacillus and Streptococcus were dominant in the 7days cover lees, the archaea Methanoculleus and the fungal Eurotium and Talaromyces were prevalent in the 60days cover lees. When the microbial community profiles in three samples were compared at species level, the prokaryotic community similarity coefficient was from 0.4042 to 0.5703 and descended to 0.2222, and that of eukaryotic community was from 0.3000 to 0.6000 and followed to 0.5215. These results suggested that microbial diversity variability and community succession have happened in the cover lees associated with fermentation proceeding and such variability and succession respond for the appearance of some unique flavor of Luzhou-flavor liquor.

Tree Species Composition, Diversity and Above Ground Biomass of Two Forest Types at Redang Island, Peninsula Malaysia

A study was conducted to determine the tree species composition, diversity and above ground biomass at Redang Island, Terengganu. Two plots of 0.1 ha were established at the inland forest and coastal forest of the island. As the result, a total of 387 trees ≥ 5 diameters at breast height (DBH) were recorded. The coastal forest recorded 167 individuals representing 48 species from 37 genera and 26 families while the inland forest had 220 individuals representing 50 species from 43 genera and 25 families. Shorea glauca (Dipterocarpaceae) was the most important species at the coastal forest with a Species Importance Value Index (SIVi) of 10.5 % while Dipterocarpus costulatus (Dipterocarpaceae) was the most important species at the inland forest with 13.8 %. Dipterocarpaceae was the most important family in both forest plots with FIVi at 20.4 % in the coastal and 21.5 % in the inland forest. The Shannon-Weiner Diversity Index (H’) was considered high in both forest plots with 3.4 (H’max = 3.9) at the coastal forest and 3.5 (H’max = 4.0) at the inland forest. Sorenson’s Community Similarity Coefficient (CCs) showed that tree species communities between the two forest plots had moderate similarity with CC = 0.5. The Shannon Evenness Index (J’) in the two forest plots was 0.89. The total above ground biomass at the coastal forest was 491 t/ha and at the inland forest it was 408 t/ha. From all the species recorded in this study, 11 species were listed as threatened species by IUCN Red Data Book, of which four were listed as endangered and critically endangered, six were listed as lower risk and one species was listed as vulnerable.

Microbial succession in the traditional Chinese Luzhou-flavor liquor fermentation process as evaluated by SSU rRNA profiles

The community succession of microbes inhabited in the fermenting lees of Luzhou-flavor liquor was investigated based on small-subunit rRNA culture independent method. All sequences recovered from fermenting lees respectively fell into the genera of Lactobacillus, Streptococcus, Bacillus, Staphylococcus, Clostridium, Pelobacter, Actobacter, Serratia, Burkholderia, Rhodoccous, Corynebacterium, Arthrobacter, Microbacterium, Curtobacterium, Leptotrichia, Methanocuuleus, Saccharomyces, Zygosaccharomyces, Saccharomycopsis, Pichia, Talaromyces, Aspergillus, Eurotium, Fomitopsis and Trichosporon. The fungal Pichia, Saccharomycopsis and Talaromyces were most abundant in the lees fermented for 1 day, the fungal Eurotium and the bacteria Burkholderia, Streptococcus and Lactobacillus were dominant in the lees fermented for 7 days, only the bacteria Lactobacillus, Burkholderia were prevalent in the lees fermented for 60 days. Most genera almost existed in the fermenting lees, while their distributions were significantly different in 1, 7 and 60 days fermented lees. The prokaryotic community similarity coefficient was from 0.5000 to 0.5455 and followed to 0.1523, and that of eukaryotic community was from 0.5466 to 0.5259 and to 0.3750 when compared at species level. These results suggested that many microbes in lees have community successions associated with fermenting and that such successions maybe contribute the fermentation process of Luzhou-flavor liquor and is main reasons that the characteristic flavor factors are produced.

Influence of navigational lock and dam structures on adjacent fish communities in a major river system

AbstractWe assessed the effects of a series of navigational lock and dam (L/D) structures on the composition of their adjacent fish communities. The Allegheny and Monongahela Rivers of southwestern Pennsylvania contain 14 lock and dam installations, eight and six respectively, which transform their river corridors into a series of contiguous pools. We selected two targeted fish assemblages, large‐bodied fishes (>250 mm TL) susceptible to gill‐netting and small‐bodied benthic species captured by trawling, for assessment upstream and downstream of each L/D installation. Gill nets were fished for approximately 16 h/net, while trawls were performed across three parallel 2‐min hauls. A total of 56 samples were collected over the spring/summers, 2004–2008. Species richness, abundance and the Jaccard Coefficient of Community Similarity (JCS) were calculated for each targeted fish community. Small‐bodied species, particularly darters, were depauperate upstream L/D while abundant and diverse downstream L/D on the Allegheny River. However, Monongahela River upstream and downstream L/D communities were similar. Jaccard Coefficient of Similarity values were comparable for both targeted fish assemblages on the Monongahela River, but differed markedly among Allegheny sites. While JCS values of large‐bodied fish assemblages of both rivers were strongly correlated with lockage frequency, this pattern was not replicated among small‐bodied assemblages. The near doubling of yearly lockages on the Monongahela River compared with the Allegheny may account for the similarity of its upstream and downstream ichthyofauna. Serial L/D navigational facilities on a large river may alter biotic connectivity patterns through physical isolation of adjacent fish communities. Copyright © 2010 John Wiley & Sons, Ltd.

Effect of Forest Harvest on the Vegetation of an Urban Park

Abstract Forested parks are an urban oasis, and forest management plays an important part in their maintenance. I used a systematic sampling technique to quantify the vegetation and propagule bank in a small urban park prior to and following a forest management event. The number of non-forest species and the abundance of Toxicodendron radicans (Poison Ivy) increased after forest harvest. Distance from an edge did not affect the change in vegetation. In the propagule bank, loss of basal area in a plot was positively correlated with an increase in the percent of species that were non-forest and non-native. The Sorenson coefficient of community similarity comparing the species composition of the vegetation before and after harvest was 0.769 (out of 1.0), but that for the propagule bank was 0.308. Forest management practices in small urban parks should be designed with extreme caution due to the volatile settings of these refuges.

Consistent, long-term change in rotifer community composition across four Polish lakes

Few studies exist documenting changes in rotifer communities over long time intervals. Here, we explore seasonal and long-term variation in rotifer communities in four Polish lakes sampled in 1976 and again in 1997. Rarefied, asymptotic species richness did not differ significantly across study years, although values in 1997 tended to be higher. Simpson’s and Shannon–Wiener diversity measures provided inconsistent temporal results, with only the former indicating significantly higher richness in 1997. Sorensen’s coefficient of community similarity was as high among lakes in 1976 (0.81) and in 1997 (0.76) as within lakes across the 21-year span (0.77). Nonlinear redundancy analysis of species’ abundances revealed large, consistent seasonal changes across lakes, smaller consistent shifts between sampling periods, and small differences between lakes. Collectively, these metrics indicate that species composition was relatively stable among lakes within years and within lakes between years, while species’ abundance patterns were far more variable and most affected by season.

Species Diversity of Edible Plants Grown in Homegardens of Chibchan Amerindians From Costa Rica

We studied edible crop species diversity at homegardens of two Chibchan Amerindian Reserves in Costa Rica: Talamanca and Coto Brus. We visited six settlements at Talamanca and five at Coto Brus. We recorded the number of edible crop species growing homegardens; we found 46 edible plant species at Talamanca and 27 at Coto Brus. The mean number of species per homegarden ranged between 3.80 and 6.80 at Coto Brus and 4.50 and 8.63 at Talamanca. We identified species that were common, i.e., found in most households and all settlements, and species that were rare. We estimated diversity indexes for each settlement and each Reserve. Also, we compared crop species composition between both Reserves and among settlements within each Reserve, using the Jaccard coefficient of community similarity. Settlements from the same Reserve were grouped together, with the exception of Villa Palacios from the Coto Brus Reserve.

Yeast Community Persistence in a Spatially Structured Environment

Community persistence was investigated in the yeast assemblage inhabiting patches of necrotic stem tissue of the columnar cactus Stenocereus gummosus (pitaya agria). Two surveys, conducted in 1981 and 1996, were compared. The variation in species occurrence in a spatial hierarchy within neuroses, among plants within a location, and among locations, was persistent across the 15-yr time span. The core species had a community similarity coefficient of 0.75, and the rank of their variability was significantly correlated for the two surveys. The physiological potential of the yeasts was distributed in the same manner in 1996 and 1981. Likewise, the rank order of physiological potentials both within plant and between plants was significantly correlated. These results indicate a microbial community that persists regionally, even though individual necroses routinely experience extinction and colonization. The role of an insect vector, Drosophila mojavensis, in community persistence is discussed.

Urbanization of a Watershed and Historical Changes in a Stream Fish Assemblage

During recent decades, the Tuckahoe Creek (Virginia) watershed has been altered by human activities, including road and bridge construction, commercial and residential development, and riparian losses. We used historical (1958) and recent (1990) data to evaluate the hypothesis that long-term, low-intensity urbanization affects a warmwater stream fish assemblage in ways usually attributed to acute, high-intensity perturbations. In 1990, fish species diversity of Tuckahoe Creek was significantly lower (P < 0.05) than it had been in 1958, and abundance was substantially lower for all species and trophic guilds. Four cyprinids, one ictalurid, and one percid present in 1958 were not collected in 1990. Jaccardˈs community similarity coefficient (species composition by site between 1958 and 1990) was negatively correlated with near-stream development of the watershed at six study sites (r = –0.84; P < 0.05). Some characteristics of the feeding ecology of selected fish species, including consumption of terrestrial prey and diet overlap, exhibited slight differences between 1958 and 1990. Observed changes in the fish assemblage were consistent with our hypothesis. Our findings also suggest that the lack of invasions by exotic fishes may not always indicate undisturbed stream conditions.

Viewpoint: Trend Assessment by Similarity: A Demonstration

Methodology for assessing trend in range condition is still evolving. This paper demonstrates use of Dice's community similarity coefficient, 2a/(2a + b + c), with communities present at 3 times and a notional community as a goal. Coefficients range from 0 (indicating a complete lack of similarity) to 1 (indicating complete similarity). Similarity is classed as low (0 - 0.25), moderate (0.26 - 0.50), high (0.51 - 0.75), or full (0.76 - 1). Study of time-goal coefficent graphs is suggested for deciding whether trend is up, down, or static. Defining goals and lack of statistical tests are major limitations. The goal concept and use of data standardization are discussed.