Shannon-Wiener Index Research Articles

Monitoring insect numbers and biodiversity with a vertical-beam entomological radar.

Concerns about perceived widespread declines in insect numbers have led to recognition of a requirement for long-term monitoring of insect biodiversity. Here we examine whether an existing, radar-based, insect monitoring system developed for research on insect migration could be adapted to this role. The radar detects individual larger (greater than 10 mg) insects flying at heights of 150-2550 m and estimates their size and mass. It operates automatically and almost continuously through both day and night. Accumulation of data over a 'half-month' (approx. 15 days) averages out weather effects and broadens the source area of the wind-borne observation sample. Insect counts are scaled or interpolated to compensate for missed observations; adjustment for variation of detectability with range and insect size is also possible. Size distributions for individual days and nights exhibit distinct peaks, representing different insect types, and Simpson and Shannon-Wiener indices of biodiversity are calculated from these. Half-month count, biomass and index statistics exhibit variations associated with the annual cycle and year to year changes that can be attributed to drought and periods of high rainfall. While species-based biodiversity measures cannot be provided, the radar's capacity to estimate insect biomass over a wide area indicates utility for tracking insect population sizes. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

Seasonal variation in marine bird distribution in the northeast Pacific Ocean

Human activities have profound influences on marine ecosystems. Marine birds are particularly sensitive to these impacts and, given their ease of observation and diverse life histories, often represent good indicators of ecosystem health. Conserving marine birds and their ecosystems requires robust predictions of species distribution to help mitigate human disturbance in areas where large aggregations of diverse species occur. We modelled variation in marine bird species diversity (Shannon-Wiener Index) and taxonomic family level probability of occurrence to map the intensity and extent of highly diverse ‘hotspots’ in Canada’s Pacific Exclusive Economic Zone. To do so, we paired 20 yr of survey data from the North Pacific Pelagic Seabird Database (1997-2017) and remote sensing data describing marine conditions and local geography (sea surface temperature, chlorophyll a, bathymetry, distance to shore, and benthic substrate type). These data were used to illustrate how seasonality within years and the El Niño-Southern Oscillation (ENSO) across years influenced spatial patterns in diversity. Hotspots were most persistent in Hecate Strait, off the west coast of Vancouver Island, and surrounding the Scott Islands in most seasons. Changes in hotspot locations and intensity were observed across seasons and within season under varying ENSO conditions. Our results provide a template for mapping marine species distribution for the purpose of identifying hotspots of diversity, and thereby facilitate planning to minimize harmful impacts in highly diverse and dynamic systems.

Variation in Fruit Traits and Seed Nutrient Compositions of Wild Camellia oleifera: Implications for Camellia oleifera Domestication

Camellia oleifera is a woody oil crop with the highest oil yield and the largest cultivation area in China, and C. oleifera seed oil is a high-quality edible oil recommended by the Food and Agriculture Organization of the United Nations. The objectives of this study were to investigate the variation in fruit yield traits and seed chemical compositions of wild C. oleifera in China and to identify the differences between wild C. oleifera and cultivated varieties. In this study, we collected wild C. oleifera samples from 13 sites covering the main distribution areas of wild C. oleifera to comprehensively evaluate 25 quantitative traits of wild C. oleifera fruit and seed chemical compositions and collected data of 10 quantitative traits from 434 cultivated varieties for a comparative analysis of the differences between wild and cultivars. The results showed that the coefficients of variation of the 25 quantitative traits of wild C. oleifera ranged from 2.605% to 156.641%, with an average of 38.569%. The phenotypic differentiation coefficients ranged from 25.003% to 99.911%, with an average of 77.894%. The Shannon–Wiener index (H’) ranged from 0.195 to 1.681. Based on the results of principal component analysis (PCA) and phenotypic differentiation coefficients, 10 traits differed significantly between wild C. oleifera and cultivated varieties, while the differentiation coefficients (VST) for fresh fruit weight, oleic acid, unsaturated fatty acids, stearic acid, and saturated fatty acids were more than 95%, of which fresh fruit weight and oleic acid content were potential domestication traits of C. oleifera. The results of this study can contribute to the efficient excavation and utilization of wild C. oleifera genetic resources for C. oleifera breeding.

Ethnobotanical studies on rice landraces under on-farm conservation in Xishuangbanna of Yunnan Province, China

BackgroundA complex interaction and mutual influence exists among landscapes, cultures, and landraces, with rice culture being a typical embodiment of this relationship. The conservation of landraces operates alongside preserving traditional practices. The Xishuangbanna region stands out as a hub for the genetic diversity of landraces, boasting rich genetic resources. Despite the diverse rice resources in this region, a comprehensive and systematic study has not been undertaken.MethodsFrom October to November 2023, we collected rice landraces under the on-farm conservation in 18 townships including Menghai, Mengla and Jinghong in Xishuangbanna. Employing semi-structured interviews and various methods, we investigated factors influencing the preservation and loss of rice landraces in the region. Statistical analysis was applied to the agronomic traits of collected local rice, encompassing indica or japonica, glutinous or non-glutinous, grain shape, and hull color as second category traits. The second category included quantitative traits like thousand grain weight and grain length. Rice diversity among different regions, traits, and ethnic groups was assessed using the Shannon–Wiener index. Additionally, clustering analysis via the UPGMA method depicted the distribution characteristics of the resources.ResultsA total of 70 rice landraces were collected in the Xishuangbanna region, each exhibiting distinct characteristics. Differences were observed across regions, trait, naming, and ethnic groups. Diversity analysis revealed that Mengla had the highest diversity, followed by Menghai, while Jinghong exhibited the lowest diversity. The second category of traits displayed broader diversity than the first, with the Dai people’s glutinous rice showcasing greater diversity than other ethnic groups. Cluster analysis categorized the 70 samples into seven groups at a genetic distance of 1.15. Ethnobotanical interviews emphasized the rapid loss of rice landraces resources in Xishuangbanna, with indigenous ethnic cultures playing a vital role in the conservation of rice landraces. Dai traditions, in particular, played a crucial role in protecting glutinous rice resources, showcasing a mutual dependence between Dai culture and glutinous rice.ConclusionsThe rich natural environment and diverse ethnic cultures in Xishuangbanna have given rise to various rice landraces. The Dai, primary cultivators of glutinous rice with higher diversity, intertwine their traditional ethnic culture with the conservation of glutinous rice resources. At the same time, the preserving glutinous rice resources promotes the inheritance of Dai ethnic culture. However, rice landraces are facing the risk of loss. Hence, collecting and documenting rice landraces is crucial. Encourage local communities to sustain and expand their cultivation, promoting on-farm conservation. These measures contribute valuable germplasm and genes for rice breeding and serve as a means of cultural preservation.

Vegetation communities and soil properties along the restoration process of the Jinqianghe mine site in the Qilian Mountains, China.

The study explores the impact of mine grassland restoration on plant communities and soil properties in alpine grasslands, a subject of significant interest due to the observed relationship between grassland changes, plant communities, and soil properties. While prior research has mainly focused on the consequences of grassland degradation on plant diversity and soil characteristics, the specific effects of varying restoration degrees in alpine mining grasslands at the regional scale remain poorly understood. To address this knowledge gap, we established 15 sampling plots (0.5m×0.5m) across five different restoration degrees within alpine mining grasslands in the Qilian Mountains, China. Our objective was to assess the variations in plant diversity and soil properties along these restoration gradients. We conducted comprehensive analyses, encompassing soil properties [soil water content (SWC), available nitrogen (AN), total phosphorus (TP), nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), total nitrogen (TN), available phosphorus (AP), soil organic carbon (SOC), nitrate nitrogen, soil pH, and electrical conductivity (EC)], plant characteristics (height, density, frequency, coverage, and aboveground biomass), and plant diversity indices (Simpson, Shannon-Wiener, Margalef, Dominance, and Evenness indexes). Our findings included the identification and collection of 18 plant species from 11 families and 16 genera across the five restoration degrees: Very Low Restoration Degree (VLRD), Low Restoration Degree (LRD), Moderate Restoration Degree (MRD), High Restoration Degree (HRD), and Natural Grassland (NGL). Notably, species like Carex duriuscula, Cyperus rotundus, and Polygonum viviparum showed signs of recovery. Principal component analysis and Pearson correlation analysis revealed that soil pH, SWC, SOC, NO3-N, and AN were the primary environmental factors influencing plant communities. Specifically, soil pH and EC decreased as restoration levels increased, while SWC, AN, TP, NH4-N, TN, AP, SOC, and NO3-N exhibited a gradual increase with greater restoration efforts. Furthermore, the HRD plant community demonstrated similarities to the NGL, indicating the most effective natural recovery. In conclusion, our study provides valuable insights into the responses of plant community characteristics, plant diversity, and soil properties across varying restoration degrees to environmental factors. It also elucidates the characteristics of plant communities along recovery gradients in alpine grasslands.

Functional diversity of the macrofauna communities in arid mangroves of the Persian Gulf and Gulf of Oman

Understanding the patterns and drivers of biodiversity in intertidal zones is essential for developing effective conservation strategies. The taxonomic and functional diversity of macrofaunal communities was studied in the arid mangrove system of the Persian Gulf and Gulf of Oman. The study further aimed to investigate whether the main functional traits differ between habitats. All macrofauna samples and environmental variables were taken from two habitats including vegetated habitat and adjoining mudflats. A total of 85 taxa was found, of which 19 taxa were exclusive to vegetated habitats and 20 to mudflats. Mollusca were the most species-rich group in both habitats, followed by Arthropoda and Annelida. When comparing diversity indices among regions and habitats the Shannon-Wiener diversity index was significantly higher in vegetated habitats compared to mudflats. However, these trends were less consistent for the functional diversity measures being very much region-dependent. The results showed that functional trait structure was more uniform than the taxonomic structure across regions and habitats. The trait modalities biodiffuser, surface deposit-feeder, burrower, free-living, planktotrophic, 2–5 years, and 10–50 mm were common at both habitats. However, the modalities detritivore and grazer/scarper, and direct larval development were significantly higher in vegetated habitats than in mudflats. The vegetated habitats exhibited the more functionally redundant communities than mudflats, possibly due to higher taxonomic diversity observed in this habitat or the presence of the species with similar functions in the ecosystem. The combined investigation of species and functional diversity of mangrove macrofauna communities conducted in this research is essential for effective management and conservation efforts aimed at protecting mangrove ecosystems and to preserve the goods and services they provide.

Temporal and Spatial Dynamics of Plankton Communities in the Lower Haora River, Tripura, India

Planktons are significant bioindicator of ecosystem functioning, knowledge of the seasonal fluctuation in the plankton population in riverine waters of Indian subcontinent is rather limited. In the present study, analysis regarding spatio-temporal variations based on different multivariate statistics and indicator value analysis is done along with analysis of community structure of plankton assemblages. A total of 46 plankton taxa out of which 38 phytoplankton and 8 zooplankton taxa have been identified based on examination of samples taken from four locations over three sampling seasons. The primary phytoplankton families that involve Chlorophyceae, Bacillariophyceae, Cyanophyceae, Euglenophyceae and Composopogonophyceae. Chlorophyceae dominated the phytoplankton population, followed by Bacillariophyceae and Cyanophyceae. The plankton abundance was recorded highest in spring, followed by winter, and the least reported in monsoon season. The high average percent contribution of Aulacoseira, Oscillatoria, and Spirogyra species is well represented through SIMPER analysis. In addition, the Shannon–Wiener index (H) was calculated to determine plankton diversity, and Pielous' Evenness index (E) was calculated to determine individual distribution within a community whereas Margalef’s Richness index showed species richness of the study area. This qualitative and quantitative study will aid future research on the occurrence of plankton as well as the more trustworthy information generation on fish diet and feeding behaviors. The condition of planktons as bioindicators would indirectly provide an estimation of the ecosystem's natural state or amount of pollution.

Plant Community Composition and Structural Pattern Dynamics in Robe-Raya Natural Forest, Southeast Ethiopia

Due to its fortuitous mix of geography, terrain, and geology, Ethiopia is the home of unique assemblages of rich biodiversity. However, this impressive biological diversity is increasingly threatened by the combined effects of different drivers before they are sufficiently investigated. The present work was carried out in Robe-Raya Natural Forest, located in Southeast Ethiopia, with the intention of examining plant community formation and structural dynamics of the forest species. Sixty (20 m × 20 m) quadrats were placed at 100 m distance along eleven east-west directed transect lines systematically. In order to gather juvenile’s data, five subquadrats (2 m × 2 m) were established within the main quadrat, distributed at each corner and middle. In each quadrat, all woody species were recorded and counted; diameter (DBH) and height were measured using tape meter and a hypsometer, respectively, and cover abundance was recorded (in %). Cluster analysis was computed using R-Package to map-out the community types. Species diversity and composition among community types were computed using the Shannon-Wiener index and Sorenson’s coefficient, respectively. Frequency, density, height, DBH, basal area, and IVI were used to analyze structural dynamics. Age-class density ratios were used to examine the regeneration status. Ninety-four woody plant species belonging to 39 families were documented. Asteraceae was the most species-rich family (10 species). The common growth form was shrubs (44.7%) followed by trees (41.5%). Cluster analysis produced four community types. In total, the species diversity and evenness were 3.75 and 0.88, respectively. The forest density and basal area were 1183.3 stems/ha and 57.52 m2·ha−1, respectively. Structural dynamics analyses demonstrated that the forest was composed of, largely, young trees and shrubs and under fair regeneration status. Certain species that have been identified to have low IVI and poor regeneration status should be prioritized for conservation.

Comparing various bio-intensive pest management modules in rice

Rice is the key cereal crop in the tropics, supporting diverse pests and natural enemy populations. Recurrent pest outbreaks and yield losses led farmers to rely on extensive insecticide application, disturbing the stability of rice ecosystems and increasing residues in the harvestable products. A study has been conducted to assess the impact of various modules of Bio-Intensive Pest Management (BIPM) on its conservational potential and sustainability in comparison with Farmers’ Practices (FP) in Nalgonda district of Telangana state during kharif-2020. The BIPM practices included application of farm yard manure; rice husk ash; clipping of seedlings; alleyways and weekly release of Trichogramma japonicum in the main field; wet seed treatment and foliar application with Pseudomonas fluorescens (BIPM 1), Trichoderma asperellum strain TAIK1 (BIPM 2) and Bacillus cabrialesii strain BIK3 (BIPM 3). Whereas, FP 1 with need-based insecticide spraying and FP 2 with schedule-based insecticide spraying and Untreated control with (UC) with no intervention. The observations were taken by visual counts at 15-day intervals. The incidence of Cnaphalocrocis medinalis was highest in UC (9.50), followed by BIPM 1 (7.25) and least in FP 2 (2.50) whereas the highest mean population of Apanteles sp. was found in the untreated control (13.75), followed by BIPM 3 (9.50) and least in FP 2 (4.25). The Benefit Cost Ratios (BCR) of BIPM 3 (1.68) were highest followed by BIPM 1 (1.64) and least in FP 2 (1.40) elucidating that BIPM practices can be more economically feasible. The Shannon-Wiener Index for species diversity and species evenness was higher in BIPM treatments as compared to farmers’ practices indicating the potential of these BIPM treatments in natural pest control and maintaining crop ecosystem stability.

Wetland vegetation composition and ecology of Lake Abaya in southern Ethiopia.

Wetland vegetation and ecology of Lake Abaya in the southern Ethiopia was studied to determine floristic composition, plant community type and vegetation ecology. A total of 102 plots were laid along transects that were set up preferentially across areas where there were rapid changes in vegetation or marked environmental gradients to collect data on estimate of percentage aerial cover of plant species and environmental variables. Vegetation data was analyzed by agglomerative hierarchical cluster analysis using similarity ratio as a resemblance index and Ward's linkage method. Multivariate data analysis was performed using appropriate packages in R version 2.14.0. Canonical Correspondence Analysis (CCA) was used to explore the relationship between the species composition and environmental variables. The environmental data included in the CCA were determined using stepwise backward and forward selection of variables by ANOVA test. Statistical measurement regarding species diversity, richness and evenness of the plant community types was carried out by using Shannon-Wiener diversity indices. A total of 92 plant species belonging to 66 genera and 34 families were identified. Families Poaceae, Asteraceae, Fabaceae, Cyperaceae, Solanaceae, Euphorbiaceae and Amaranthaceae account for about 56.99% of the total proportion. Based on the cluster analysis, five plant community types were identified. The most important factors influencing the plant species composition and pattern of wetland plant communities were water drainage, water depth, land use, slope, altitude, and hydrogeomorphology. Therefore, these factors should be considered in future management and protection under the circumstance of climate change and human activities.

Identification of biotic and abiotic factors coal mine overburden on Warukin rock formation of South Kalimantan

Overburden (the dumping of mine tailings and other reject materials) from the Warukin geological formation is one of the potential acid-forming (PAF) of 33.17%. Mining can cause overburden to be exposed and affect biotic and abiotic conditions. The study aimed to analyze the biotic and abiotic factors of three different age overburdens from the Warukin Formation, South Kalimantan. Biotic factor measurements included vegetation sampling using line transect, soil insects using pitfall traps, and microbial using total plate count. Abiotic factor measurements included air temperature and humidity, light intensity, temperature, moisture, and pH of the substrate (n=3), and chemical overburden. Identification of plants and insect species using information from locals, identification books, and websites. Plant species diversity was analyzed using the Shannon-Wiener Index. Dominance species were analyzed using the Important Value Index (IVI). The relation of overburden age on biotic and abiotic factors was analyzed multivariate with Non-Metric Multidimensional Scaling (NMDS). The results showed that there are 102 species of plants and 11 species of soil insects. The numbers of fungi and bacteria are 10-4 CFU g-1 and 10-3 CFU g-1, respectively. Plant species diversity is classified as medium (H'= 2.34; 2.50 and 2.82). Changes in plant composition occurred as the microclimate and substrate nutrition improved. The organic matter increased over time. Humidity and light intensity influence the presence and composition of organisms, while pH values affect the adaptability of plants, insects, and microbes. Heavy metal concentrations have increased due to the physicochemical properties of the Warukin formation overburden.

Soil quality assessment of oak forests invaded by moso bamboo (Phyllostachys edulis) in the northern subtropics

Soil quality is closely related to the evolution of forest ecosystems, especially in the context of global warming; therefore, it is essential to study the changes in soil quality caused by the invasion of moso bamboo in its habitat. In this study, we selected plantation forests and natural secondary forests with typical vegetation of the northern subtropics, Quercus acutissima plantation (QAP) and oak secondary forest (OSF), collected plant community and soil physicochemical data, and established a soil quality index (SQI) to assess how moso bamboo invasion affects soil quality. In addition, the mechanisms driving the moso bamboo invasion effects on soil quality were investigated using a partial least squares structural equation model (PLS-SEM). The results demonstrated that: (1) Moso bamboo invasion significantly affected community structure and soil physicochemical properties, there were inconsistent changes in soil physicochemical indicators in oak forests of different origins, and in general the effects of moso bamboo expansion on soil physicochemical properties were concentrated in the topsoil (0–20cm). (2) Soil bulk density (BD), total soil porosity (TSP), total nitrogen (TN), and available potassium (AK) comprised the minimum data set (MDS) used to calculate the SQI, and the SQI of oak forests of different origins ranged from 0.48 to 1, and the invasion of moso bamboo led to a significant decrease in the SQI of the surface layer of QAP. A redundancy analysis (RDA) showed that soil quality assessment factors were closely related to community structure and the PLS-SEM indicated that moso bamboo invasion indirectly affected surface soil quality through its effects on community and soil factors. The results showed that moso bamboo invasion had different effects on oak forests of different origins. They also showed that soil quality was strongly affected by aboveground biomass (AGB), the tree Shannon-Wiener index (TH'), and available potassium (AK).

陕西神木弃耕1–49年的苜蓿地土壤理化特性和植物物种多样性数据集

The abandonment of alfalfa fields is on the rise in semi–arid regions. It is important to clarify the changes of soil water content, soil bulk density, soil porosity, soil saturated water conductivity, soil pH, soil NH4-N, NO3-N, soil available phosphorus, soil organic carbon, soil total nitrogen, Margalef index, Pielou index, Simpson index, and Shannon–Wiener index in abandoned alfalfa fields, which is essential for vegetation restoration efforts in semi-arid areas. This dataset is credited to the National Field Scientific Observation and Research Station of Shenmu Erosion and Environment in Shaanxi Province (also referred to as Shenmu Station). we conducted surveys on alfalfa fields in 2003, 2014, and 2022 with varying abandonment periods (1-30 years, 12-41 years, and 20-49 years, respectively) to obtain data on soil physicochemical characteristics and plant species diversity. This dataset was compiled in strict adherence to international observation technical standards, including field investigations, laboratory measurements, data calculations, data storage, and quality control procedures. The high-quality data can serve as solid foundation for the study of alfalfa succession process in semi-arid areas.

The role of slope as an environmental variable in plant biodiversity change in Aegean rangelands by SHE analysis: The case of Çakmar rangeland

Rangelands, which have rich plant and animal biodiversity, are also very important as a source of roughage for livestock. Rangeland vegetation patterns vary considerably under the influence of environmental factors. Indicator factors need to be identified and analyzed in order to manage conservation and utilization objectives. In rangelands of the Aegean region, the slope factor can greatly affect the rangeland plant biodiversity in areas close to the base rangeland. In order to investigate the spatial distribution and species variation in plant biodiversity caused by slope, 6 rangeland sections with different slopes were sampled in Koçarlı region (Aydın / Türkiye). Sampling was carried out using the transect method in the spring 2017 based on field observations. Following sampling, indicator species and species distribution and abundance were determined. Alpha biodiversity indices were used to determine the change in species biodiversity by SHE analysis. SHE analysis tests the relationship between S (species richness), H (Shannon-Wiener diversity index) and E (equality). This method aims to examine the contribution of the number of species and the concept of equity in the context of diversity. According to the information obtained as a result of the analysis, it was seen that the increase in slope may cause a decrease in species biodiversity. More species diversity was found in rangelands with low base and slope. Factors such as erosion and water transport affect the canopy and species abundance in high slope rangelands. However, other factors such as grazing intensity can reverse this situation. For this purpose, it has been determined that slope is an important environmental variable when preparing management plans based on grazing capacity and grazing animal species in vegetation studies.

2021年山东长岛毗邻海域底层渔业生物监测数据集

As one of the most representative areas of the shelf-edge sea, the waters adjacent to offshore islands are important sea-land transition areas. The ecosystems in these areas are diverse and complex due to the dual regulation of natural environmental variabilities and human activities. The adjacent waters of the Changdao Island are characterized by typical island ecology and are key migration channels, spawning grounds and habitats of fishery resources in the Bohai Sea and Yellow Sea, which are of great significance to the food web process of fishery organisms in this area. From March to December 2021, the Shandong Changdao Fishery Resources National Observation and Research Station conducted a month-by-month survey of bottom fishery stocks with 10 stations per cruise and sample measurements in the waters adjacent to the Changdao Island. Afterwards, the index of relative importance (IRI), species replacement rate, catch per unit effort (CPUE), D (Margalef richness index), H′ (Shannon-Wiener diversity index) and J′ (Pielou evenness index) were calculated from the biological measurement data of the catches that formed the present dataset. The review and proofreading of this dataset was thoroughly conducted through extensive full-sample cross-checks by multiple reviewers to guarantee the standardization and accuracy. This dataset can provide data support for the study of spatial and temporal patterns of bottom fishery stocks in the Bohai Sea and Yellow Sea and the study of special island fishery ecosystems with migratory passage characteristics.

Assessing the vulnerability of oil-dependent countries in Europe

In this article, we attempt to assess the vulnerability of European oil-dependent countries, using the Weighted Russell Directional Distance Model, which provides a composite index and allows for the analysis of adjustments in different proportions for the evaluation factors to reduce oil vulnerability. Our empirical findings show heterogeneous degrees of vulnerability to oil across countries due to country-specific characteristics. More precisely, Slovakia, the Czech Republic, Sweden, France, the Netherlands, and Spain emerged as the least oil-vulnerable countries. Conversely, Hungary, Poland, and Portugal performed poorly regarding oil supply security. Our productivity analysis indicates that inefficient countries that experienced productivity gains primarily achieved them through technological progress, with the Shannon-Wiener index playing a crucial role. These findings align with the EU's strategy of diversifying supply sources.

Species and structural diversity of trees at the structural type level

BackgroundSpecies and structural diversity are important for understanding the formation of forest communities, key ecological processes, and improving forest ecological functions and services, but their spatial characteristics have received little attention. Based on the spatial relationships among neighbouring trees, we proposed to divide trees within a structural unit into 15 structural types, and used the univariate distributions of the uniform angle index (W), mingling (M), and dominance (U), along with four common species diversity indices, to analyse the diversity of structural types in natural forests near the Tropic of Cancer.ResultsOnly a portion of clumped class maintained aggregation, most exhibited a random pattern. Species mixture increased exponentially across distribution classes, and abundance and richness exhibited an initial increase followed by a slight decrease. The distribution patterns of mixture classes varied from highly clustered to random, and M distributions gradually shifted from an inverted J-shaped curve to a J-shaped curve. Abundance and richness exhibited an exponential distribution, whereas the Shannon–Wiener index increased linearly. The W distribution of differentiation classes approximated a normal distribution, whereas M distributions exhibited a J shape. The U distribution of each structure type was approximately 0.2.ConclusionsThese results reveal the species and structural diversity characteristics of trees at the structural type level and expand our knowledge of forest biodiversity. The new method proposed here should significantly contribute to biodiversity monitoring efforts in terrestrial ecosystems, and suggests that higher standards for the simulation and reconstruction of stand structure, as well as thinning in near-natural forests, is warranted.

Climate and soil stressed elevation patterns of plant species to determine the aboveground biomass distributions in a valley-type Savanna.

Extreme environments such as prolonged high temperatures and droughts can cause vulnerability of vegetation ecosystems. The dry-hot valleys of Southwestern China, known for their extremely high annual temperature, lack of water, and unique non-zonal "hot island" habitat in the global temperate zone, provide exceptional sites for studying how plant adapts to the prolonged dry and hot environment. However, the specific local biotic-environment relationships in these regions remain incompletely elucidated. The study aims to evaluate how valley-type Savanna vegetation species and their communities adapt to long-term drought and high-temperature stress environments. The study investigated the changes in species diversity and communities' aboveground biomass of a valley-type Savanna vegetation along an elevation gradient of Yuanmou dry-hot valley in Jinsha River basin, southwest China. Subsequently, a general linear model was utilized to simulate the distribution pattern of species diversities and their constituent biomass along theelevation gradient. Finally, the RDA and VPH mothed were used to evaluate the impacts and contributions of environmental factors or variables on the patterns. The field survey reveals an altitudinal gradient effect on the valley-type Savanna, with a dominant species of shrubs and herbs plants distribution below an elevation of 1700m, and a significant positive relationship between the SR, Shannon-Wiener, Simpson, and Pielou indices and altitudes. Relatively, the community aboveground biomass did not increase significantly with elevation, which was mainly due to a decreased biomass of herbaceous plants along the elevation. Different regulators of shrub-herbaceous plant species and their functional groups made different elevation patterns of species diversity and aboveground biomass in valley-type Savannas. Herbaceous plants are responsible for maintaining species diversity and ensuring stability in the aboveground biomass of the vegetation. However, the influence of shrubs on aboveground biomass became more pronounced as environmental conditions varied along the altitudinal gradient. Furthermore, species diversity was mainly influenced by soil and climatic environmental factors, whereas community biomass was mainly regulated by plant species or functional groups. The study demonstrates that the spatial pattern of valley-type Savanna was formed as a result of different environmental responses and the productive capacity of retained plant species or functional groups to climate-soil factors, highlighting the value of the Yuanmou dry-hot Valley as a microcosm for exploring the intricate interactions between vegetation evolution and changes in environmental factors.

Evaluating Relationship between Surface Water Quality and Zooplankton Diversity in Coastal Areas of Tien Giang Province, Vietnam

The zooplankton diversity is the most important ecological parameter for water quality assessment, as these small creatures are sensitive to any changes in water quality, hence the objective of this study as to evaluate the relationship between surface water quality and zooplankton diversity in the coastal areas of Tien Giang province, Vietnam using appropriate standard methods. The results showed that the coastal water quality had high concentrations of suspended solids, ammonium and coliforms. A total of 71 zooplankton species with a total density ranging from 3,219,383 to 24,993,634 individuals/m3 were identified. Among the zooplankton species, Copepoda nauplius appeared at all monitoring stations, predominating with a density ranging from 740,800 to 7,555,250 individuals/m3. The values of the Shannon-Wiener diversity index (H') ranged from 1.54 to 2.37, reflecting the coastal water quality in the study area from polluted to mildly polluted. The coastal water variables of pH, salinity, DO, NH4+-N and coliform were closely correlated with the density of zooplankton species. The relationship between surface water quality and zooplankton diversity could be a basis for selecting biological indicators to monitor coastal water quality.

Diversity and species richness of avian fauna in varied habitats of Soraipung range and vicinity in Dehing Patkai National Park, India

Dehing Patkai National Park, nestled in Assam’s Upper Brahmaputra valley, features a distinctive lowland forest landscape dominated by Dipterocarpus trees, teeming with fauna encompassing reptiles, birds, and mammals. Avian surveys were conducted from October 2021 to September 2023 to document avifaunal diversity within and surrounding the park. Point-transect method was used. One-hundred-and-fifty-one species from 54 families were recorded, including 43 terrestrial and 11 aquatic bird families. One-hundred-and twenty-seven species were residents, 18 winter migrants, five summer migrants, and one was a local migrant. Habitat disturbance was assessed across five transects; undisturbed habitats in T1 and T2 showed the highest Shannon-Wiener diversity index, while moderately and highly disturbed habitats in T3, T4, and T5 exhibited lower diversity. The analysis revealed a significant positive correlation (p ≤ 0.05) among different transects. A total of seven species (Ashy-headed Green Pigeon, Lesser Adjutant, White-cheeked Partridge, Alexandrine Parakeet, Red-breasted Parakeet, Austen’s Brown Hornbill, and Oriental Darter) are classified as ‘Near Threatened’ in the IUCN Red List of Threatened species; 12 species are in Schedule 1 under the Wildlife (Protection) Act, 1972. This investigation underscores Dehing Patkai National Park’s significance as a sanctuary for diverse bird populations, including threatened and near-threatened species. The decline in bird populations in disturbed areas emphasizes the urgency of implementing effective conservation and management strategies within the park, alongside continued research and monitoring to support its unique avian ecosystem.