Shannon-Wiener Index Research Articles

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.

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.

Macrobenthic Community Structure and Water Quality Evaluation in Ulungu River Basin (Northwest China)

In this study, the composition and structure of the macrobenthic community in the Ulungu River Basin was investigated and the water quality status of the basin was evaluated. In May and August 2022, and October 2023, the macrobenthic and water environmental factors at 11 sample sites in the basin were investigated, and the water quality of the basin was evaluated by the Shannon–Wiener index, FBI, and BMWP index. A total of 6101 macrobenthic organisms were collected; these organisms belonged to 3 phyla, 7 classes, 14 orders, 57 families, and 117 genera. Arthropod species accounted for the largest number of species (87.9%). A total of nine dominant species were found: Micronecta sp., Eukiefferiella sp., Baetis sp., Polypedilum sp., Saetheria sp., Ephemerella sp., Limnodrilus sp., Ephemera sp., and Hydropsyche sp. At the temporal level, the average density and biomass of macrobenthos were in the order of August > October > May; at the spatial level, the average density was greater in the tributaries than in the main stream, and the average biomass was greater in the main stream than in the tributaries. The mean values of the Shannon—Wiener index and Margalef richness index were as follows: August > October > May at the temporal level; the mean values of the Pielou evenness index were as follows: May > October > August at the temporal level. At the spatial level, the overall mean value of each diversity index indicated that the tributaries had larger diversity indices than the main stream. The water quality evaluation results revealed that the overall water quality level of the Ulungu River Basin ranges from light pollution to poor quality. Human interference activities greatly impact the water quality of the basin. To restore the ecology of the basin, it is necessary to strengthen the management and control of pollution sources.

Microenvironment created by Plantago lagopus L. may affect cover and diversity of coexisting species in urban vegetation

Some plant species may exhibit new microenvironments which lead to significant changes in the cover and diversity of the coexisting species. In this investigation, we evaluated the effects of Plantago lagopus L. on the cover and diversity of the associated plant species in the urban vegetation. A total of 70 plots were conducted in sites with- and without this species in urban gardens. Cover of the associated species and different diversity indices including species richness, Shannon-Wiener, evenness, and Simpson indices were measured. The allelopathic potential of P. lagopus was verified using its rhizosphere and non-rhizosphere soils on two target species existing within the same environment. Some soil criteria and seed sizes of the associated species were also determined. Most of the coexisting weeds were reduced in terms of their cover in plots with Plantago. The reduction of plant diversity depended on its cover. Besides, the aboveground biomass was reduced in sites comprising Plantago. The degree of inhibition was not related to the seed size of the species found. This species reduced the incident solar radiation and the local temperature over the soil surface. The locations exhibiting such species contained lower contents of available potassium and zinc. Rhizosphere soil of P. lagopus substantially inhibited germination and growth of Amaranthus viridis, but it didn't do so for Medicago lupulina. Reduction in cover, diversity, and biomass of the urban weeds associated with P. lagopus may be related to the reduction of received solar radiation, soil temperature, and nutrient availability. The allelopathic potential of P. lagopus may have a partial role in this reduction. These results suggest that P. lagopus may create a microenvironment of new conditions not favorable for most of the coexisting species.

Field evaluation the effect of two transgenic Bt maize events on predatory arthropods in the Huang-Huai-Hai summer maize-growing region of China.

To illustrate the impact of genetically modified (GM) Bt maize on the natural enemy communities in the Huang-Huai-Hai summer maize-growing region in China, the abundance of 7 common predator taxa (Geocoris pallidipennis Costa, Harmonia axyridis (Pallas), lacewings, Orius sauteri (Poppius), Propylea japonica (Thunberg), spiders, and Staphylinidae) was quantitatively evaluated by comparing Bt-Cry1Ab DBN9936 and Bt-Cry1Ab/Cry2Aj Ruifeng 125 events to their near non-Bt isolines during the growing season from 2016 to 2019. A total of 10,302, 19,793, 13,536, and 5,672 individuals were observed during 4 years, and the abundance of each taxa on Bt maize varied between sample dates among those arthropod taxa. Shannon-Wiener diversity index of predator communities from 7 taxa showed very similar temporal dynamics and principal response curve analyses to examine community-level effects showed no significant differences in predator abundance in Bt maize compared with non-Bt maize. We conclude that the 2 Bt maize hybrids did not adversely affect the predator community in the Huang-Huai-Hai summer maize-growing region of China.

Impacts of locust feeding on interspecific relationships and niche of the major plants in Inner Mongolia grasslands

Oedaleus decorus asiaticus (O. asiaticus), the dominant species of steppe locust, plays a crucial role in driving the dynamic changes of the grassland ecosystem. However, there are a limited number of studies on the impact of locust feeding on the relationship of the major plants in the species community. This study has employed the Shannon-Wiener index, Pianka index, and the maximum information coefficient (MIC) to assess the impact of O. asiaticus feeding on the community structure and interspecific relationships in the grasslands of Inner Mongolia. The chosen indices measured niche breadth, niche overlap, and interspecies correlation. The topological network structure between the main species was further analyzed. The results indicated that: 1) locust gnawing expands the niche width of major species and increases the niche overlap index of food-loving species; 2) the feeding of locusts reduces the overall correlation between species but increases the interspecific relatedness between food-loving species and other species. 3) the number of links in the species topological network structure is reduced due to locust gnawing.

Diversity of Hymenopteran Parasitoids in different Crop Ecosystems

Surveys were carried out in different districts viz., Shivamogga, Davangere and Chitradurga of Karnataka to collect and document hymenopteran parasitoids parasitizing insect pests attacking different crop ecosystems. A total of 42 hymenopteran parasitoids species represented by 33 genera belonged 12 families were documented from a collection of 1379 specimens from different stages viz., egg, larva, pupa and adult stage of host insects from different host plants viz., rice, maize, cabbage, cotton, coconut, brinjal, cashew, crape jasmine, tobacco, field bean, soybean, arecanut, cocoa, okra and pongamia. Among them, maximum parasitoids species (20) were collected from larval stage of host insects with per cent species composition of 47.62. Among the families, Braconidae was found most dominant (comprised of 23.81%), followed by Eulophidae (16.67%), Encyrtidae and Scelionidae (each with 14.29%). Alpha and beta diversity were computed for the three zones. Species diversity in terms of richness, evenness and abundance of hymenopteran parasitoids were calculated and compared during study period using Shannon-Wiener index, Simpson diversity index, Margalef’s diversity index, Menhinick’s index and Evenness. Species diversity was high in Shivamogga district as evidenced by Shannon-Wiener index (2.49), Simpson diversity index (0.88), Margalef’s index (4.09) and Menhinick’s index (1.22) and Evenness (0.46), followed by Davanagere district with respect to Shannon-Wiener index (1.69) Simpson’s diversity index (0.75), Margalef’s index and Menhinick’s index (2.27 and 0.90), respectively, while evenness was 0.24 and Chitradurga district with respect to Shannon-Wiener index (1.34) Simpson’s diversity index (0.54), Margalef’s index and Menhinick’s index (2.12 and 0.59), respectively.

Grazing alters the soil nematode communities in grasslands: A meta-analysis

Grazing causes great disturbances in grassland ecosystems and may change the abundance, diversity, and ecological function of soil biota. Because of their important role in nutrient cycling and as good environmental indicators, nematodes are very representative soil organisms. However, the mechanisms by which grazing intensity, livestock type, duration, and environmental factors (e.g., climate and edaphic factors) affect soil nematodes remain poorly understood. In this study, we collected 1964 paired observations all over the world from 53 studies to clarify the grazing response patterns of soil nematodes and their potential mechanisms. Overall, grazing significantly decreased the abundance of bacterial-feeding (BF) nematodes (−16.54%) and omnivorous-predatory (OP) nematodes (−36.81%), and decreased nematode community diversity indices (Shannon–Weiner index: −4.33%, evenness index: −9.22%, species richness: −5.35%), but had no effect on ecological indices under a global regional scale. The response of soil nematodes to grazing varied by grazing intensity, animals, and duration. Heavy grazing decreased OP nematode abundance, but had no effect on the abundance of other trophic groups, or on diversity or ecological indices. Grazing by small animals had stronger effects than that by large animals and mixed-size animals on BF, fungal-feeding (FF), plant-feeding (PF) and OP nematodes, the Shannon–Wiener index, and the species richness index. The abundance of FF and OP nematodes influenced significantly under short-term grazing. The evenness index decreased significantly under long-term grazing (>10 years). Climate and edaphic factors impacted the effects of grazing on nematode abundance, diversity, and ecological indices. When resources (i.e., rain, heat, and soil nutrients) were abundant, the negative effects of grazing on nematodes were reduced; under sufficiently abundant resources, grazing even had positive effects on soil nematode communities. Thus, the influence of grazing on soil nematode communities is resource-dependent. Our study provides decision makers with grazing strategies based on the resource abundance. Resource-poor areas should have less grazing, while resource-rich areas should have more grazing to conserve soil biodiversity and maintain soil health.

Taking spontaneous plants as a natural strategy for vegetation restoration in construction and demolition waste landfills: a case study in Suzhou, China.

Construction and demolition waste (CDW) landfills around the city have caused serious damage to the ecological environment and menaced the public health. Restoration of closed CDW landfills is critical to compensate for the degraded ecosystem and ensure safety in further development and utilization. Vegetation restoration is an essential part of the restoration of CDW landfills, in which the use of spontaneous plants is the foundation of the nature-based strategy. In this study, Fenghuangshan CDW landfill in Suzhou, China, was selected as the research site, and the species composition and diversity of the spontaneous plants were analyzed. Moreover, the types of habitats and growth indexes of 8 species with high frequency and 18 species with medium frequency in the CDW landfill were investigated, and a comprehensive evaluation of growth rate and expansion capacity of the 26 species was conducted. The results showed that, herbs were the main type of the spontaneous plants in the CDW landfill. The species and quantities of the spontaneous plants in the CDW landfill were obviously fewer than those in the surrounding areas of the CDW landfill, and the Shannon-Wiener index and Pielou index of the spontaneous plants were lower compared with the surrounding areas of the CDW landfill. Meanwhile, the differences of dominant families and the distribution of origins, life forms and growth types between these two fields were insignificant. The heliophilous and drought tolerance species were widely distributed in the CDW landfill while the shade-tolerant or hygrophilous species were few. The relatively large comprehensive evaluation indexes of Elymus dahuricus, Daucus carota, Sonchus asper, Geranium carolinianum, Rumex acetosa, Metaplexis japonica, Carex breviculmis, Erigeron canadensis, Trigonotis peduncularis, Lamium amplexicaule reflected their high growth rates and strong expansion capacity, demonstrating their great potentiality in the vegetation restoration of CDW landfills as indispensable components of the nature-based solution.