Margalef Richness Index Research Articles

Diversity of Insects of Two Rice (Oryza sativa L. 1787) Farms in Nnamdi Azikiwe University, Awka, Nigeria

The recognition of insect-related damages to rice plants and the subsequent consequences for biodiversity have shown the relevance of insect communities in rice farms. This study documented the insect fauna of rice (Oryza sativa L. 1787) in two rice farms in Nnamdi Azikiwe University, Awka, Nigeria from September to November, 2022. The insects associated with the two sites were collected using handpicking, sweep net, water trap and pitfall trap methods. Data collected from the study were subjected to non-parametric t- test at 5% significant level. A total of 51,021 insects belonging to twelve insect orders were found associated with the two sites. Out of the aforementioned number, 15,120 (29.63%) were collected from site 1 while 35,901 (70.37%) were collected in site 2. There was significant difference (P <0.05) on insect abundance between site 1 and 2. Crematogaster peringueyi was found to be the most abundant (82.67%) insect in site 1, whereas Camponotus perrisi was found to be the most abundant (27.85%) in site 2. The result further showed that only Hobomok skipper had the least relative abundance (0.01%) in site 1, while Catantops quadratu, Anacatantops notatus, Dysdercus cingulatus, Crematogaster peringueyi, Dasyleurotettix infaustus and Apis mellifera had the least relative abundance (0.01%) in site 2. The diversity indices computed showed that Site 1 had a higher Simpson dominance index (0.6845), Shannon Weiner diversity index (1.07597) and Shannon Weiner evenness than site 2 (0.0019, 0.41248and 0.0393 respectively). The Margalef richness index (6.3879) of site 2 was greater than site 1 (4.9876).There is need for regular monitoring of insects in rice farms for sustainable management of the crop.

Taxonomic and functional diversity of aquatic macroinvertebrate from natural forest as reference for streams health indicators in Lasolo Watershed, Southeast Sulawesi, Indonesia

Abstract. Nasaruddin N, Sabaruddin L, Analuddin K, Sudia LB. 2023. Taxonomic and functional diversity of aquatic macroinvertebrate from natural forest as reference for streams health indicators in Lasolo Watershed, Southeast Sulawesi, Indonesia. Biodiversitas 24: 5523-5538. Macroinvertebrates are known to play a crucial role in nutrient recycling and serve as valuable stream degradation indicators. Therefore, this study aimed to examine the structural and functional diversity of macroinvertebrate communities as a reference for stream health indicators in tropical Sulawesi, Indonesia. Spatial sampling using a multi-habitat method was conducted between September 2021 and March 2022 in five streams connected to natural forest and three from drainage areas in dryland farming. Data on forest cover, physical-chemical variables, and macroinvertebrate samples were collected, while the species richness and diversity trends across streams were analyzed using individual rarefaction curves. In addition, the composition of macroinvertebrate functional group was also evaluated. The results showed that 2474 individuals belonging to 77 genera were recorded throughout the area. We found a reduction in taxa composition by comparing the reference and impacted stream at the genus, family, and order levels with approximate values of 83.1%, 74.07%, and 55.6%, respectively. At least seven significantly different potential metrics that differentiated between reference and the impacted ecosystem were found, including the number of family taxa (#family), the number of insect taxa (#insect), the number of Ephemeroptera-Plecoptera-Trichoptera taxa (#EPT), the number of scraper taxa (#scraper), as well as Shannon-Wiener diversity, Simpson Evenness, and Margalef Richness index. These metrics offer a strong method for assessing land use change and their impact on freshwater biodiversity, emphasizing the importance of conservation efforts in the ecosystem.

Effect of environmental drivers of fish assemblage and diversity patterns in temporal scale in Mongra Reservoir: A case study from one of the tributaries of Mahanadi Basin, Central India

AbstractInfluence of seasonal variations in environmental parameters on fish assemblage and species diversity patterns was studied in a tropical reservoir of Central India during March 2021 to February 2022. A total of 41 species belonging to 7 orders, 15 families and 29 genera were recorded with highest diversity during post‐monsoon season compared to the pre‐monsoon season and monsoon season. The fish abundance similarity between the monsoon and post‐monsoon reached a maximum of 89%. Seasonal variations in the mean species abundance, Simpson dominance index, Shannon diversity index, Pielou's evenness index and Margalef's richness index were determined. One‐way ANOVA revealed a significant difference (P < 0.05) at the temporal scale. There was a significant seasonal difference in species abundance (P = 0.0006) and evenness index (P = 0.02) among the diversity indices. During the study period, three ‘vulnerable’ species, three ‘near threatened’ species and two ‘endangered’ species were caught. Carnivore dominance was evident throughout the year in the trophic guild of fishes. The Pearson correlation test revealed that water pH, dissolved oxygen, sediment organic carbon and clay percentage were positively correlated to all four diversity indices. Simpson and Margalef species richness diversity indices were positively correlated to sediment pH. Fish abundance was positively associated with sediment pH, silt, phosphorus and nitrogen content. Canonical correspondence analysis was used to investigate the relationships between fish assemblages and environmental conditions. Among the 19 physicochemical parameters, nine (dissolved oxygen, total dissolved solids, conductivity, transparency, hardness, phosphate and chlorophyll‐a, sediment nitrogen and phosphorus) characteristics were shown to be statistically significant (P < 0.05) in determining fish diversity. Dissolved oxygen, total dissolved solids, conductivity, transparency, hardness, phosphate and chlorophyll‐a of water and sediment nitrogen and phosphorus qualities were the key factors for the species abundance. The reservoir boasts a diverse fish population that allows multi‐species fishing and generates revenue for numerous local fishers. Fish habitats should be protected in order to maintain diversity and long‐term ecological benefits.

Used macroinvertebrates as bioindicators to compare water quality from different land uses in Watumokala and Nokambu Rivers, Southeast Sulawesi, Indonesia

Abstract. Kahirun, Basrudin, Siwi LO, Indriyani L, Bana S, Sudia LB, Erif LOM, Midi LO, Maulina N, Jamaluddin N. 2023. Used macroinvertebrates as bioindicators to compare water quality from different land uses in Watumokala and Nokambu Rivers, Southeast Sulawesi, Indonesia. Biodiversitas 24: 5693-5708. Macroinvertebrates are animals that live in waters, both on the surface of the water, in riverbeds attached to substrates or mud, and in several biotypes, which are used as bioindicators of water quality due to anthropogenic disturbances that can change land use around rivers. This study aimed to describe the physicochemical parameters and macroinvertebrate community in the Watumokala and Nokambu rivers in Southeast Sulawesi, Indonesia, and to compare the water quality in the two rivers based on ecological index measurements. This study used a survey method at the upstream, middle, and downstream sampling locations for each river with different land use. Data collection on macroinvertebrates and physicochemical parameters was carried out at each station in each river. The data analysis carried out in this study was to calculate the Shannon-Wienner diversity index, species abundance index, uniformity index, Margalef richness index, and the Family Biotic Index (FBI). The results of this study indicated that in the Watumokala River, there were 17 families from 9 macroinvertebrate orders with an abundance of 1852 individuals, more than in the Nokambu River where 14 families were found from 8 orders with an abundance of 904 individuals. There is an influence of land use habitat on macroinvertebrates in the Watumokala and Nokambu Rivers. In the Watumokala River station 1 and station 3 are similar and have a significant correlation with several indicators indicating that the water quality is still good, while at station 2 there is a positive correlation with physicochemical parameters which indicates that the water quality is slightly polluted. Likewise, in the Nokambu River, at station 1 and station 2, there are similarities and significant correlations between physicochemical parameters and macroinvertebrate communities in providing indicators that water quality is still good, while station 3 shows a significant correlation with physicochemical parameters and macroinvertebrates as indicators of water quality polluted. So, the results of this research are useful in efforts to manage land and water in rivers that are experiencing pollution.

Spatial and temporal distribution of fish egg communities in the adjacent waters of Daya Bay nuclear power plant and their relationship with environmental factors

The thermal discharge of Daya Bay Nuclear Power Plant has a certain impact on the ecological environment of the adjacent waters. In order to understand and evaluate changes in the fish egg community structure in the adjacent waters of Daya Bay Nuclear Power Plant and their relationship with environmental factors, four surveys were conducted to investigate fish eggs in January (winter), March (spring), August (summer) and November (autumn) of 2020. A total of 100,985 fish eggs were collected and 17 taxa were identified, belonging to five orders, 14 families and 17 genera. Among them, Perciformes and Clupeiformes were the main contributing taxa to fish egg species and abundance in the waters adjacent to Daya Bay Nuclear Power Plant. The number of fish egg species ranged from high to low was summer, spring, autumn and winter; the average abundance ranged from high to low was spring, summer, winter and autumn. The results showed that except in winter, the average abundance of fish eggs was greater in northeast area than in southwest area. The Shannon-Weiner species diversity index (H’), Pielou evenness index (J’) and Margalef richness index (d) were significantly different between seasons, but none were significantly different between areas. The results of NMDS analysis showed that there were significant differences in fish egg communities between seasons. Surface seawater temperature the average abundance of fish eggs was positively correlated in the results of all four seasons. Although the entrainment effect of nuclear power plant water intake and thermal pollution of partial waters owing to thermal discharge can cause some loss of fish eggs, fish resources can still be effectively maintained.

MACROFAUNAL DIVERSITY ON THE SURFACE SEDIMENT OF MANGROVE HABITAT ADJACENT TO THE SEAGRASS BEDS AT PUNANG- SARI RIVER ESTUARY (MALAYSIAN BORNEO), SOUTH CHINA SEA

Macrofaunal diversity and composition are essential to understanding the ecosystem structures and functions of mangroves in any dynamic estuarine coast. To understand the temporal distribution of macrofaunal community structures and diversity on the surface sediment in the intertidal mangrove forest next to the seagrass beds, this study was conducted at Punang-Sari-River estuary, Lawas, Sarawak (Malaysian Borneo), South China Sea. Sampling was done during post-monsoon, intermediate-September, pre-monsoon, and monsoon from July 2019 to February 2020. The mean macrofauna abundance was higher pre-monsoon, while Gastropoda Optediceros breviculum (L. Pfeiffer, 1855) was the most abundant (RA = 0.704). Important Species Index (ISI = 70.36) and percentage of contribution (64.97%) were also higher for this species than any other records from the site. The ANOSIM (Analysis of Similarity), Jaccard index and SIMPER (Similarity Percentage Analysis) analysis suggested that the highest species abundance similarity was observed between pre-monsoon and monsoon, while the highest dissimilarity was observed between intermediate-September and pre-monsoon (74.67%). Seasonal PCA, nMDS, and cluster analysis revealed that pre-monsoon and monsoon were comparable in species and individual abundance. The dominance (0.85) was found significantly higher (P < 0.0001) in intermediate-September, while Simpson (0.734), Shannon (1.56) and Evenness indices (0.528) were found higher in monsoon, followed by the higher Margalef richness indices (3.21) in post-monsoon. It was observed that the seasonal ecological parameters were found to be significantly (P < 0.05) different, including the temperature, salinity, rainfall, pore water nitrogenous compounds (NO2, NO3 and NH3-N), phosphorus compound (PO4) and micro minerals. The Canonical Correspondence Analysis (CCA) results suggested that ecological factors influenced several species. Considering the few studies on mangrove macrofauna in Malaysian Borneo, further research on their trophic structures and food web interactions is very important to disclose their overall characteristics and ecosystem functions.

Study of Ecological Diversity of Predatory Asopinae Bugs in the Agro-ecosystem of the Mid-Western Plains

The aim of the present study was to investigate the seasonal abundance of Asopinae predatory stink bugs within an agro-ecosystem. This research was carried out by utilizing sweep nets to collect these insects during the period spanning from May to August in the year 2022. The survey yielded two prominent species of predaceous bugs, specifically Andrallus spinidens and Eocanthecona furcellata. Interestingly, E. furcellata emerged as the dominant species within the field conditions. A noteworthy phenomenon occurred in June when a sudden surge in the population of both species was observed. This population increase was attributed to the presence of lepidopteran larvae in the field, which likely served as a rich food source for these predatory stink bugs. The ecological analysis revealed some important findings regarding the diversity and distribution of these insects in the agro-ecosystem. Specifically, the Shannon Diversity Index was notably low, registering at less than 1.99, indicating a limited variety of species within the sampled population. Similarly, the Simpson Index indicated a low degree of diversity or heterogeneity, falling within the range of 0.01 to 0.04, which further supports the notion of a relatively homogeneous population. Additionally, the Margalef Richness Index signalled a level of disturbance, measuring less than 2.05. This disturbance could be linked to various factors affecting the ecosystem, including changes in agricultural practices or environmental conditions. Lastly, the Dominance Index was relatively high, ranging between 0.5 and 1.0, signifying that a few dominant species, particularly E. furcellata, exerted a significant influence within the ecosystem. In summary, the ecological indices suggested limited diversity, low heterogeneity, disturbance, and dominance within the stink bug population, shedding light on the dynamics of these beneficial insects in the agro-ecosystem.

Benthic macroinvertebrates community in relation to environmental variables of the Cimandiri River and Estuary, Indonesia

Benthic macroinvertebrates, the community that lives in the river and coastal, play important role in the transfer of organic materials. This study aimed to determine the diversity of it in Cimandiri river and estuary. Also, to understand the relation between the community with environmental variables. The research was conducted in September and November 2020, which taken from 10 locations at Cimandiri waters. Benthic macroinvertebrates were collected using the Ekman grab sampler with three replications. Moreover, physicochemical parameters of water and sediment were measured. In general, about 35 taxa belonging to six Classes, including Gastropod, Bivalve, Insect, Malacostraca, Clitellata, and Polychaeta have been found during sampling. Furthermore, Stenelmis sp., one of Insects was predominant benthic invertebrates in the river, whereas Tarebia granifera predominated inhabit the estuary. Margalef richness and Shannon-Wiener diversity index in the river area were about 2.69 and 1.47, while in the estuary was around 1.59 and 0.87. Canonical Correspondence Analysis shows that the number of individuals of 25 taxa tended to correlate with water temperature, TDS, salinity, total of nitrate (TN), total of phosphorus (TP), and total of organic matters (TOM). While, 10 other taxa correlated with pH, turbidity, dissolved of oxygen (DO), ammonia, and the total of suspended solids (TSS).

Bird diversity in several land use types in Boyolali, Central Java

Land use changes were thought to affect the diversity and feeding guilds of bird species. This research aims to determine the effect of five land use types (rice fields, settlements, cropland, tree plantation, and secondary forest) on species diversity and feeding guilds of bird species in Boyolali Regency. Methods used were the standard point count and the MacKinnon species list. Bird data were analyzed using the Margalef richness index, Shannon-Wiener diversity index, Pielou evenness index, and Sorensen community similarity. The total species recorded was 46 species from 26 families. The land use types with the lowest to the highest number of species are settlements, rice field, tree plantations, cropland, and secondary forests. The highest number of species found was in secondary forest (n = 25), along with the highest richness (DMg = 4.17), diversity (H′ = 2.689), and evenness (J′ = 0.835) indices. Although the secondary forest has the highest number of species and indices, other land uses in rural areas also serve as good bird habitats. The insectivorous, frugivorous, and granivorous guilds were found in all land use types. The carnivorous guilds were only found in secondary forests.

Riparian Vegetation Structure of the Jengok River, Kutaliman, Kedungabanteng District, Banyumas Regency

Jengok River has a high value for the Kutaliman community. The community utilizes the ecosystem services of the Jengok River and is inseparable from the presence of riparian vegetation, which controls water quality. This study aimed to determine riparian vegetation structure on the Jengok River, Kutaliman, Kedungbanteng district, and Banyumas Regency. The research was conducted in October-November 2022 in the Jengok riparian zone using a quadrat transect with sizes 20x20 m2 for trees dan 2x2 m2 for understoreys. Data were analyzed using the Shannon-Wiener Diversity Index (H'), the Modified Hill's Ratio Evenness Index (e'), the Margalef Richness Index (DMg), and the Important Value Index (IVI). The results show that the diversity of riparian vegetation based on the Shannon-Wiener Diversity Index (H') is a moderate category, and the Evenness Index (e') is the distribution of individuals per species evenly. Furthermore, the Margalef Richness Index (DMg) shows 4.51 for trees and 4.34 for understorey. The highest IVI in the tree stratum was Lansium domesticum Corrêa. In contrast, in the understorey stratum was Musa paradisiacal L. This indicates both species have an essential role in their community

Taxonomic diversity of the macrobenthos and its relationship with environmental factors in the Huanghe River (Yellow River) estuary and adjacent seas, China

Data on the macrobenthos, bottom seawater, and sediment from 26 sampling stations in the Huanghe River estuary and adjacent seas in China, were collected in June 2020. Community structure, species diversity, taxonomic diversity of the macrobenthos, and the relationships of these variables with environmental factors were analyzed. The funnels and contours of average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+) were used to indicate the disturbance status of the estuary seas. These findings revealed differences in macrobenthic community structure and biodiversity between the estuary and the adjacent seas. A total of 88 macrobenthic species were collected in the Huanghe River estuary and its adjacent seas. Abundances in the estuary, Section C, and Section D were 60 ind. m−2, 183 ind. m−2, and 320 ind. m−2, respectively, The biomass in the estuary, Section C, and Section D was 6.74 g·m−2, 15.72 g·m−2, and 9.07 g·m−2, respectively. There were significant differences in the number of species and their abundances between the estuary and adjacent seas (p < 0.01). Glycinde bonhourei, Sternaspis scutata, Moerella hilaris, Liljeborgia serrata, Iphinoe tenera, and Lineus sp. were the dominant species. The community dissimilarity of the estuary and adjacent seas reached >79.66% (p = 0.001). The results of k-means clustering analysis showed that the macrobenthic community could be divided into three types. High Margalef richness index (d) and Shannon–Wiener diversity index (H′) values were observed in the northern portion of the estuary and the seas in Laizhou Bay. The theoretical mean values of Δ+ and Λ+ were 90.8 and 267.7, respectively. High values of Δ+ were observed in Section A2-B2-C2-D2 where the communities were distantly related. Low values were observed in Laizhou Bay. The distribution of Λ+ was the complete opposite of that of Δ+. Deviations in the 95% confidence interval were observed at five stations (A2, A3, B1, B2, and D2). The northern sea of the Huanghe River estuary was disturbed. Spearman correlation analysis showed that ∆ was positively correlated with total organic carbon, heavy metals, fine silt, and clay. Heavy metal and TOC in the Huanghe River estuary and adjacent seas may be positively correlated with the reproduction of opportunistic species.

Characteristics of phytoplankton community and its influencing factors in the Yanhe River Basin, Northwest China.

Yanhe River is one of the important tributaries of the Yellow River, with a vital role in the maintenance of biodiversity and ecological conservation in the middle reaches of the Yellow River. In this study, we conducted a systematic aquatic ecological survey of the Yanhe River Basin in spring (April-May) and autumn (September-October) of 2021, with phytoplankton as indicator organism. A total of 33 sampling sections were selected in the mainstem, five first-class tributaries, and impounded water bodies (reservoir and check dam water bodies) of the Yanhe River Basin. The results showed that a total of 253 phytoplankton species, belonging to 7 phyla and 91 genera, were detected in the two surveys. Diatoms and green algae prevailed in spring (168 species), while diatoms and cyanobacteria dominated in autumn (179 species). The mean phytoplankton density and biomass were 316.07×104 cells·L-1 and 6.41 mg·L-1 in spring, and 69.56×104 cells·L-1 and 1.59 mg·L-1 in autumn, respectively. At the temporal scale, phytoplankton abundance in spring was higher than that in autumn. At the spatial scale, the phytoplankton abundance in the middle and lower reaches of the mainstream was higher than that in the upper reaches. Phytoplankton biomass in the impounded water bodies formed by dam interception was maintained at a high level, which was significantly higher than that in the mainstem and tributary water bodies in autumn. The phytoplankton diversity, as indicated by Shannon diversity index, Margalef richness index, and Pielou evenness index, in spring was greater than that in autumn. Phytoplankton diversity was greater in the trunk and tributary waters than that in impounded waters. The results of redundancy analysis showed that the key factors driving the phytoplankton community structure in spring were flow velocity, dissolved oxygen, nitrite nitrogen, and water depth. In contrast, the key driving factors in autumn were nitrate nitrogen, water depth, and dissolved oxygen.

Modelling the ecological impact of invasive weed Verbesina encelioides on vegetation composition across dryland ecosystems of Punjab, northwestern India.

Events of climate change have led to increased aridification, which alters local vegetation patterns and results in the invasion of opportunistic species. Though many studies assess the impact of invasive weeds and aridification at the agronomic level, studies investigating changes in local vegetation are severely lacking. We investigated the impact of the invasive plant Verbesina encelioides (Asteraceae) on the local vegetation composition across different dryland ecosystems in Punjab, northwestern India. Based on the aridity index for the period of 1991-2016, three major dryland ecosystems, i.e., arid, semi-arid, and sub-humid, were found in Punjab. The impact of V. encelioides on local biodiversity was measured in terms of species diversity (using Shannon's diversity index, Simpson's dominance index, Hill's evenness index, and Margalef's richness index), species composition (using non-metric multidimensional scaling based on Bray-Curtis's dissimilarity index), and species proportion in the two invasion classes (uninvadedandinvaded) and across the three aridity zones (arid, semi-arid, and sub-humid). The vegetation survey depicted the presence of 53 flowering species belonging to 22 families, including 30 exotics and 23 natives. Verbesina encelioides decreased species diversity and proportion, with a more pronounced impact in arid and semi-arid ecosystems. In contrast, species composition varied between uninvaded and invaded classes only in arid ecosystems. Ecological parameters derived from population statistics (number of individuals) were more drastically affected than those from species abundance data. Since the ecological impacts of V. encelioides were manifested with increased aridification, it is a matter of apprehension under the potential climate change scenario.

Diversity and Distribution of 18 Cephalopod Species, and Their Link with Some Environmental Factors in the NW Pacific

Some cephalopods are important fishery resources, with some major economic species living in pelagic waters, possessing short life history cycles, and responding strongly to environmental changes. The analysis of cephalopod community species composition, catch distribution, and their relationship with environmental factors in important marine areas can provide a basic reference for cephalopod biogeography and resource development and utilization. In this study, based on the cephalopod survey data in the spring of 2015 and summer of 2016 in the Pacific Ocean, we analyzed the cephalopod species composition, diversity index (the Margalef richness index, Shannon–Wiener diversity index, and Pielou uniformity index), main contributing species, and catch distribution in the two seasons of spring and summer in the Pacific Ocean. We also analyzed the relationship between cephalopod catch, each diversity index, and environmental factors in each season using the GAM model. The results show that 18 species of cephalopods were captured in the spring and summer, the Margalef richness index, Shannon–Wiener diversity index, and Pielou uniformity index in summer was higher than that in spring; the average catch biomass in spring was significantly higher than that in summer. The main contributing species in spring was Todarodes pacificus, while the main contributing species in summer was Ommastrephes bartramii. The interaction of the “longitude” and “latitude” has a great impact on cephalopod catch biomass in spring, and “sea surface temperature” has a great impact on cephalopod catch biomass in summer. The results of the study can provide a basic reference for the study of cephalopod diversity and resource development and utilization in the Pacific Ocean.

Empirical assessment of species vulnerability for biodiversity conservation: A case study on Chalan beel of Bangladesh

The study was conducted to assess the current biodiversity in Chalan beel, Natore district, Bangladesh. Primary data were collected through stratified random sampling and analyzed through a combination of descriptive statistical and mathematical techniques. The Shannon-Weiner and Margalef richness indices were used to quantify the biodiversity of birds, and fauna. The Shannon-Weiner diversity index was 2.097, 0.944, and 1.510 for the fish, bird, and other faunal communities, respectively. The Species Ability to Forestall Extinction (S.A.F.E.) index was used to enumerate threatened status among native birds and other faunal species in Chalan beel areas and the IUCN conservation status was assessed simultaneously. The most threatened community was birds, which comprised 28.12% of critically endangered species. According to the weighted perception index, 90.0% of respondents agreed with positive statements, and 89.0% agreed with negative statements, regarding the effects of natural disasters on biodiversity and the significance of the factors was justified through the multinomial logit model. The reasons for the depletion of fish and waterfowl were identified according to farmers’ responses, and failure mode effect analysis (FMEA) was used to rank the causes of depletion according to intensity. This study identified the overall biodiversity status of Chalan beel as a representative wetland to assist policymakers in conservation.

Spatial and temporal variations of zooplankton assemblage in Chiffa Wadi (North Algeria).

The spatial and temporal variations in the distribution, abundance, and assemblage structure of zooplankton were examined in the Chiffa Wadi River, north central Algeria. Samples were taken seasonally from autumn 2020 to summer 2022. Nine physical and chemical variables were recorded, and their relationship with the density of 39 zooplankton species was established using canonical correspondence analysis. In order to study the structure of the zooplankton, Shannon-Wiener diversity indices (H'), Margalef richness index (Dmg), Pielou evenness (E), and abundance were calculated. During the analysis, rotifera was the dominant group in the zooplankton community, represented by 27 taxa, followed by Cladocera (9 taxa) and Copepoda (3 taxa). The diversity index indicated the higher richness, abundance, and evenness of zooplankton at a eutrophic site (S2) compared with other sites. The canonical correspondence analysis (CCA) showed that the structure of zooplankton is influenced by local environmental factors. The present study demonstrates that anthropogenic activities including urban discharge and the construction of Algeria's Medea-Chiffa highway, which increased the nutrient load in the aquatic system, disrupted water quality. Consequently, the distribution and quantity of zooplankton were dramatically impacted by these changes in water quality.

Response of Understory Plant Diversity to Soil Physical and Chemical Properties in Urban Forests in Beijing, China

Understory vegetation affects the richness and stability of urban forest ecosystems. To investigate the influence of soil physicochemical properties on the diversity of understory plants in urban forests, this study used 30 urban forest communities in the Beijing Plain area as the research object and analyzed the correlation between understory plant diversity and soil factors by correlation analysis. Furthermore, pH, soil bulk density (SBD), total soil porosity (TSP), soil water content (SWC), soil organic carbon (SOC), soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), effective phosphorous (AP), and effective potassium (AK) were determined in this study. The Shannon diversity index (H’), Pielou evenness index (E), Simpson dominance index (C), and Margalef richness index (DMG) of understory plants were calculated. The soil nutrient contents and the understory plant diversity indices of the different community types showed significant differences. There was a strong correlation between soil properties and the diversity index of understory vegetation. SOM and SOC were the main factors affecting the Shannon-Wiener index, Pielou index, Simpson index, and Margalef richness index of the understory plants. We conclude that soil properties were one of the primary drivers of the formation of understory vegetation diversity. The results of the study can provide scientific guidance for the management of urban forests.

Preliminary endophytic fungi richness index of the Rio de Janeiro restinga

The preservation of the Restinga biome is of great importance, both ecologically and socially, and this ecosystem is threatened mainly by anthropic actions, with little known about its fungal diversity. Endophytic fungi, besides contributing to the prospecting of new efficient compounds in industry and agriculture, can indicate the richness and abundance of species in the areas where they are found. Thus, the objective of this work was to carry out an inventory of endophytic fungi prospecting from plant species in the Açu, Gargaú, Grussaí, and Jurubatiba restingas, located in the north of Rio de Janeiro State, Brazil. Leaves of 78 plant species were collected, from which 1787 isolates were obtained in culture medium, identified in 36 different genera. After analyzing the data of richness and abundance of the fungi found, the biodiversity of the four restingas was estimated, indicating a high diversity in the ecosystem, being the restinga of Açu the most preserved and the restinga of Gargaú the most degraded when evaluated by Margalef Richness Index.

Fish diversity and assemblage in the Batticaloa lagoon, Sri Lanka.

The Batticaloa Lagoon (Sri Lanka's third-largest brackish waterbody) has suffered habitat degradation and water quality deterioration during the past 30 years due to various anthropogenic activities. Despite Sri Lanka having 40 lagoons, inventories on the lagoon ichthyofauna are rather meagre and data on fish diversity and assemblages are scarce. An assessment of fish diversity is essential to maintain the ecological stability and lagoon fisheries. This study examined the fish fauna of the Batticaloa lagoon considering the northern and southern regions of the lagoon and various depths through a 3-year survey (2017-2019) and documented the dominant and rare fish species. In addition, biodiversity measures, species assemblages and the role of environmental parameters on the distribution of fishes were documented. Various diversity indices (the Margalef richness index, the Shannon-Weiner diversity index, Pielou's evenness index, the dominance index, the taxonomic diversity index, the average taxonomic distinctness index and the total taxonomic distinctness index) were calculated. Analysis of similarities (ANOSIM) was used to examine the seasonal and regional differences in the fish assemblages. The survey showed the occurrence of 96 species belonging to 40 families and 11 orders. Ambassis gymnocephalus was the most abundant fish species (8.7% of the total number of fishes collected) followed by Etroplus suratensis (6.8%), Arius maculatus (6.1%), Gerres filamentosus (5.3%), Oreochromis niloticus (4.6%) and Gerres abbreviates (3.9%). Dasyatis uarnak (0.02%), Acanthurus gahhm (0.03%), Alectis ciliaris (0.04%) and Crossorhombus valderostratus (0.08%) were considered as rare species which constitute less than 0.1% of the total while D. uarnak was considered a doubletons species (represented twice in the whole sample of 16 stations). Two types of species assemblages, one in the northern region and one in the southern region, were evident in a dendrogram (Based on the samples were collected on each region dendrogram were plotted with respect to sites then finally dendrogram of one region pratly connected by other region) based on sample composition similarity estimated with a Bray-Curtis matrix and nonmetric multidimensional scaling plots. The Bray-Curtis dissimilarity was 59.03% between the two regions, indicating statistically significant differences in assemblages (ANOSIM R 0.801; P < 0.01). The northern region of the lagoon had a higher number of species, density, Margalef richness, Pielou's evenness, Shannon-Wiener diversity, taxonomic diversity, taxonomic distinctness and total taxonomic distinctness compared to the southern region. The northern region showed significantly higher levels of salinity and dissolved oxygen (DO) and the southern region higher temperature, turbidity, phosphates and nitrates. The best subset of biota and environmental variables [BEST(BIO-ENV)] test showed a significant relationship between fish assemblage and environmental parameters. Distance-based linear model analysis showed a significant relationship between fish assemblage and the environmental parameters salinity, temperature, pH and DO. The sequential test of this analysis showed the environmental parameters to explain about 74.9% (R2 ) of the total variation. The bioenvironmental model developed was found to be appropriate. Thirteen species were found to be influential as they explained the overall fish distribution pattern with a Spearman rank correlation of 0.951. Ten groups of coherent species were also identified in the study area. In stations having anthropogenic activities, the fish diversity was low. The fish fauna of the Batticaloa lagoon should be monitored periodically to protect the fishery resources here. An understanding of the role that environment plays in structuring the fish assemblage in the Batticaloa lagoon and locations with critical habitats will be of great importance in the conservation and management of fishery resources in this lagoon. However, as monitoring only the dominant species may fail to pick up on important impacts affecting the less common species, it should be done using diversity indices and rare fish species. Monitoring is imperative in view of the livelihood of the fishers this lagoon supports and the health of the local people, as fish is a healthy food. The fishery resources of this lagoon must be protected for posterity with appropriate management measures.

Ichthyofaunal diversity of Bhagairia Lake in Bardiya District, Nepal

This study was conducted to assess the ichthyofaunal diversity of Bhagairia Lake located in Bardiya district, Nepal from August 2019 to February 2020. For this research monthly sampling was done to assess ichthyofaunal diversity and water quality parameters i.e. water temperature, water transparency, total dissolved solids, dissolved oxygen, pH, alkalinity, total hardness, ammonia, phosphate and nitrate from six sites around the lake. A total number of 30 species of fish belonging to 8 orders, 13 families and 23 genera were recorded. Among these, Cypriniformes and Cyprinidae were the dominant order and family covering 50% and 44 % of fish species, respectively. Puntius sophore was found to be the dominant fish species with a catch composition of 12%. Maximum fish catch (214 individuals) was recorded in February whereas, minimum fish catch (140 individuals) was recorded in August. The fish catch was found to be positively correlated with dissolved oxygen (r= 0.912), pH (r= 0.876), alkalinity (r= 0.840) and total hardness (r= 0.876). Shannon diversity index was the highest in August (3.14) and lowest in November (2.87). Margalef's richness index was highest in the month of August (5.276) and lowest in February (3.727) whereas, Sheldon evenness index was highest in February (0.925) and lowest in September (0.823). This study revealed that Bhagairia Lake is rich in fish faunal diversity and consists of native, cultivable, ornamental and rare species of fish.