Cyanobacteria colonize stone monuments around the world. However, the species diversity depends on the substratum and climatic conditions. We documented the seasonal diversity of cyanobacteria in the ...monuments of Santiniketan and Bishnupur. Though in summer seasons, temperatures on the surface of these monuments go from 45 to 49 °C, we observed the highest diversity of 27 species of cyanobacteria in the summer season. Here, we report for the first time, the presence of Brasilonema sp. from the monuments of Bishnupur and Santiniketan. Bayesian phylogenetic analysis shows it form a strong clade with other Brasilonema sp. along with Scytonema rivulare. We found a reduced form of scytonemin from Brasilonema sp., which might protect against UV and high light. We carried out canonical corresponding analysis (CCA) since we found a significant difference in environmental parameters. Our study shows species like Gloeocapsa sanguinea, Lyngbya arboricola, Scytonema geitleri were positively correlated with environmental parameters. Chroococcus minor is highly influenced by light intensity and relative humidity, whereas Scytonema geitleri was much influenced by light intensity. We also extracted and characterized scytonemin, a UV-absorbing compound from Brasilonema sp. which might be helping it in survival under high light and UV irradiation.
•Seasonal diversity of cyanobacteria on the two stone monuments was documented. .•During summer season, the highest diversity of Cyanobacteria is reported .•We reported Brasilonema sp. for the first time from the monuments of India .•Phylogenetic analysis shows similarity with other Brasilonema sp. along with Scytonema rivulare.•CCA analysis shows environmental parameters having much influence on cyanobacteria diversity.
The current analyses of vegetation were aimed to study the different effects of environmental variables and plant species and communities interaction to these variables, identified threats to local ...vegetation and suggestion for remedial measures in the Mount Eelum, Swat, Pakistan. For assessment of environmental variability quantitative ecological techniques were used through quadrats having sizes of 2×2, 5×5 and 10×10m2 for herbs, shrubs and trees respectively. Result of the present study revealed 124 plant species in the study area. Canonical Correspondence Analysis (CCA) was used to analyze the ecological gradient of vegetation. The environmental data and species abundance were used in CANOCO software version 4.5. The presence absence data of plant species were elaborated with Cluster and Two Way Cluster Analysis techniques using PC-ORD version 5 to show different species composition that resulted in five plant communities. Findings indicate that elevation, aspect and soil texture are the strongest variables that have significant effect on species composition and distribution of various communities shown with P value 0.0500. It is recommended to protect and use sensibly whole of the Flora normally and rare species particularly in the region.
The sweet cherry fruit quality traits (soluble solid content, titratable acidity, pH and soluble solid titratable acidity ratio), phytochemical content (total phenolic content and total monomeric ...anthocyanins) and antioxidant activity were determined in five Italian autochthonous genotypes and compared with two commercial cultivars for 4 consecutive years. Significant influences of genotype, crop year and their interaction on the variables under study was observed. The autochthonous cultivar "Ciliegia di Udine", on average, showed the highest values for all the investigated parameter whereas the lowest ones were reported for the largely cultivated cultivar "Ferrovia" (Germersdorfer). Beside the genotype, crop year and its climatic conditions affected fruits quality and "Flamengo Srim" showed the best response taking into consideration fruit quality traits, phytochemical content and antioxidant activity and their quali-quantitative stability across the experimentation.
The wild vegetation of the Eastern Desert is characterized by openness and comprises perennials and ephemerals. The current study investigated the relationship between the edaphic factors of the ...natural vegetation along El Sheikh Fadl–Ras Gharib Road, Southwest Suez Gulf, in the northern sector of the Eastern Desert. The vegetation structure of the study area is relatively simple. The surveyed plants included 93 species from 22 families (51 perennials and 42 annuals). Asteraceae, Brassicaceae, Amaranthaceae, and Fabaceae were the richest families, constituting the majority of plant species (53.76%). Therophytes were the most frequent life forms. About 83.87% of the total flora were pluriregional elements of different affinities. Most of the recorded taxa occupied the Irano-Turanian/Mediterranean/Saharo-Sindian/Sudano-Zambezian chorotypes. The application of TWINSPAN classification resulted in grouping the vegetation into three main vegetation groups (A, B, and C), representing distinct microhabitats. The CCA ordination indicates diversity in vegetation group A. Group B was highly associated with Na, Mg, CaCO3, silt, clay, and C/N. Group C showed a high correlation with sand, K, and N. The differences in wild plant life forms, richness, and diversity along the studied desert roadsides, in association with the soil differences, provide a good indication of plant biodiversity.
After applying canonical correspondence analysis to metagenomics data with hugely different library sizes (site totals) it became evident that Canoco and the R-packages ade4 and vegan can yield (at ...least up to 2022) very different
P
-values in statistical tests of the relationship between taxonomic composition (species composition) and predictors (environmental variables and/or treatments). The reason is that vegan and Canoco up to version 5.12 apply residualized response permutation (but ignore the model intercept), whereas ade4 applies predictor permutation. Predictor permutation, when extended to residualized predictor permutation, is applicable in partial constrained ordination. This paper shows by simulation that residualized response permutation can yield a very inflated Type I error rate, if the abundance data are both overdispersed and highly variable in site total. In contrast, residualized predictor permutation controlled the type I error rate and had good power, also when the predictors were skewed or binary. After square-root or log transformation of the abundance data, the differences between the permutation methods became small. Residualized predictor permutation is recommended, particularly in testing trait–environment relationships using double constrained correspondence analysis, because this method also critically depends on the species totals, which are generally highly variable. It is implemented in Canoco 5.15 and the R-code of this paper.
Environmental stressors present a hierarchical influence on freshwater organisms. This study investigates the hierarchy of environmental stressor gradients, which regulate the composition of instream ...macroinvertebrate communities of northern Italy (Po Valley and the south-eastern Alps). Species and environmental data were derived from 585 monitoring sites. Environmental parameters were split into three groups, describing (i) ecoregional, (ii) hydromorphological, and (iii) water quality attributes. Partial Redundancy Analysis (partial RDA) was used to hierarchically rank the group effects, which were expressed as unique (group specific) and joint effects (of two groups together). Overall, ecoregion explained more variance (30.2%) than hydromorphology (24.8%) and water quality (22.3%). Unique effects were generally low, but ecoregional unique effects were twice as high as those of the other groups. The analysis of single environmental variables highlighted significant effects of anthropogenic impact related to the substrate size composition, riparian vegetation, flow conditions, and Escherichia coli (surrogate descriptor of organic fecal pollution). Such stressor hierarchies can support biodiversity conservation plans, while the high joint effects of stressor groups suggested the need for combined management activities, addressing the respective stressors and stressor groups in concert. Management measures addressing only one stressor group isolated from others are likely to be less effective, or even ineffective.
Understanding relationships between vegetation and environmental variables is very important for ecosystem restoration and management efforts in middle Taihang Mountain of North China, However, ...information on how environment factors influence the long-term natural restoration process is lacking. The objective of this research is to identity controlling environmental variables over natural restoration process in middle Taihang Mountain of North China using multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA). Vegetation and soil surveys were performed in 144 permanent sampling plots in Niujiazhuang Catchment in 1986 and 2008. Vegetation variables include shrub height, shrub coverage, shrub biomass, herb height, herb coverage, herb biomass, species richness (S), Shannon–Wiener's (H), Simpson's predominance index (D), and evenness index (Jsw). Topographic variables include elevation, slope, slope position, and slope aspect. Soil variables include soil thickness, humus thickness, rock content, soil organic matter, and total N, P, and K. Results indicate that the most important factors that influence the composition of vegetation assemblages (diversity, distribution and above-ground biomass) were total K in 1986 and total P in 2008. Also, the results suggest significant correlations among vegetation variables, soil nutrient contents, and topographic variables. For example, total N, P, and K were positively correlated with soil organic matter significantly. Relationships between vegetation and environmental variables over long-term natural restoration provide some valuable implications for regional ecological restoration and land management. To restore the degraded ecosystems, maintain the diversity and structure of ecosystems in middle Taihang Mountain, we should consider the co-evolution of both vegetation and soil, and also natural succession sequence.
The present study aimed to determine floristic composition, the structure of the vegetation, and species distribution at 16 sample plots in Wadi Fatimah, Mecca, Saudi Arabia, highlighting the ...ecological factors that affect species distribution. The study revealed 100 plant species belonging to 34 families. Fabaceae and Poaceae were the dominant families, and chamaephytes and therophytes were predominant life forms, which demonstrate a typical desert life-form spectrum. Altitude showed a highly significant association with species frequency distribution. The highest species richness value of 23 species per plot was recorded in the coastal plain (Vegetation groups II & III). The lowest species richness value of 9 species per plot was recorded in the littoral salt marsh (Vegetation group I). Chorological analysis exhibited the Saharao-Arabian-Sudano-Zambezian chorotypes, 47% of the studied species were bi-regional. Using TWINSPAN, DCA, and CCA multivariate analysis, four major vegetation groups were classified into three main ecosystems (I) Halopeplis perfoliata, Suaeda fruticosa, Acacia tortilis, and Suaeda fruticosa, representing the littoral salt marsh; (II) Rhazya stricta and Haloxylon salicornicum, characterized by the coastal plain; and (III) Senna italica, Glinus lotoides, and Tribulus macropterus were the leading groups in the inland mountainous country. The CCA ordination showed that the separation of Vegetation group III along the axis was affected by Mg, K, and P concentration, and VG IV was significantly associated with silt, clay, and fine sand content. Furthermore, the Vegetation group I was significantly correlated with Na and Ca concentration, and VG II group was significantly correlated with heavy metal concentrations of elements as Fe, Pb, Zn, Ni, and Cu.
The emergence of several diseases affecting amphibian populations worldwide has prompted investigations into determinants of the occurrence and abundance of parasites in frogs. To understand the ...spatial scales and identify specific environmental factors that determine risks of parasitism in frogs, helminth communities in metamorphic frogs of the northern leopard frog (
Rana pipiens
) were examined in relation to wetland and landscape factors at local (1 km) and regional (10 km) spatial extents in an agricultural region of Minnesota (USA) using regression analyses, ordination, and variance partitioning techniques. Greater amounts of forested and woody wetland habitats, shorter distances between woody wetlands, and smaller-sized open water patches in surrounding landscapes were the most consistently positive correlates with the abundances, richness, and diversity of helminths found in the frogs. Wetland and local landscape variables were suggested as most important for larval trematode abundances, whereas local and regional landscape variables appeared most important for adult helminths. As previously reported, the sum concentration of atrazine and its metabolite desethylatrazine, was the strongest predictor of larval trematode communities. In this report, we highlight the additional influences of landscape factors. In particular, our data suggest that anthropogenic activities that have resulted in the loss of the availability and connectivity of suitable habitats in the surrounding landscapes of wetlands are associated with declines in helminth richness and abundance, but that alteration of wetland water quality through eutrophication or pesticide contamination may facilitate the transmission of certain parasite taxa when they are present at wetlands. Although additional research is needed to quantify the negative effects of parasitism on frog populations, efforts to reduce inputs of agrochemicals into wetlands to limit larval trematode infections may be warranted, given the current high rates of amphibian declines and extinction events.
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