Shannon-Wiener Diversity Index Research Articles

Floristic diversity of mangroves and mangrove associate species of Kali River Estuary, Karwar, Karnataka, India

This study assessed the mangrove flora of the Kali River estuary, Uttara Kannada district, Karnataka. Fourteen true mangrove species belonging to eight families and 11 genera were documented from four locations: Devbagh, Mavinhole, Kalimatha Island, and Halgejoog. The mangrove species show a discontinuous distribution pattern in the Kali River estuary. The highest IVI in true mangroves was recorded for Avicennia officinalis at Devbagh, Acanthus ilicifolius at Mavinhole, Sonneratia caseolaris (after Oryza coarctata) at Kalimatha Island, and S. caseolaris (after Derris trifoliata) at Halgejoog. Of the four sites, Devbagh has the highest Shannon-Wiener diversity index, and with regard to species composition, Devbagh and Kalimatha Island are the most similar sites. Kalimatha island has the most well-preserved mangrove community.

Comprehensive Evaluation and Selection of 192 Maize Accessions from Different Sources.

In the period 2022-2023, an analysis of fourteen phenotypic traits was conducted across 192 maize accessions in the Aral region of Xinjiang. The Shannon-Wiener diversity index was employed to quantify the phenotypic diversity among the accessions. Subsequently, a comprehensive evaluation of the index was performed utilizing correlation analysis, principal component analysis (PCA) and cluster analysis. The results highlighted significant findings: (1) A pronounced diversity was evident across the 192 maize accessions, accompanied by complex interrelationships among the traits. (2) The 14 phenotypic traits were transformed into 3 independent indicators through principal component analysis: spike factor, leaf width factor, and number of spikes per plant. (3) The 192 materials were divided into three groups using cluster analysis. The phenotypes in Group III exhibited the best performance, followed by those in Group I, and finally Group II. The selection of the three groups can vary depending on the breeding objectives. This study analysed the diversity of phenotypic traits in maize germplasm resources. Maize germplasm was categorised based on similar phenotypes. These findings provide theoretical insights for the study of maize accessions under analogous climatic conditions in Alar City, which lay the groundwork for the efficient utilization of existing germplasm as well as the development and selection of new varieties.

Anthropogenic disturbance produces divergent effects in the community structure and composition of tropical semi-evergreen forests in the Eastern Himalaya

Studies documenting anthropogenic disturbance-driven changes in forest communities of the Eastern Himalaya, a global biodiversity hot spot, are largely lacking. We studied six forest sites of tropical semi-evergreen forests in Arunachal Pradesh in the Eastern Himalaya to understand the effects of varying disturbance intensities on the forest community structure and composition. Based on the magnitude of disturbance, forest sites were classified as experiencing low, moderate and high disturbance. Mean species richness (SR) of trees and shrubs decreased from low disturbance to high disturbance. Mean SR of herbs was maximum in moderately disturbed forest sites. Maximum values of the Shannon-Wiener Diversity Index (SD) were recorded for trees at sites with low disturbance, for shrubs at sites with high disturbance and for herbs in moderately disturbed forests. Pilelou Evenness Index (EI) values were maximum for trees at sites with high disturbance, while maximum EI values for shrubs and herbs were recorded in the forest sites with low disturbance. The number of tree families decreased from 18 to 13 in the forests with low and high disturbance, respectively. Moderate disturbance led to increased herb species richness and diversity, while increasing disturbance produced contrasting effects on trees. High anthropogenic disturbance led to low species richness, but high diversity amongst shrubs. Our investigations suggest that the magnitude of disturbance elicits differential responses in different physiognomic classes in the forest ecosystems and further our understanding of the effects of disturbance in tropical forest ecosystems of a global biodiversity hotspot.

Responses to phytoplankton community succession and expression of key functional genes in plateau lakes under 17β-estradiol interference

Steroid estrogens (SEs) have garnered global attention because of their potential hazards to human health and aquatic organisms at low concentrations (ng/L). The ecosystems of plateau freshwater lakes are fragile, the water lag time is long, and pollutants easily accumulate, making them more vulnerable to the impact of SEs. However, the knowledge of the impact of SEs on the growth and decomposition of phytoplankton communities in plateau lakes and the eutrophication process is limited. This study investigated the effects and mechanisms of SEs exposure on dominant algal communities and the expression of typical algal functional genes in Erhai Lake using indoor simulations and molecular biological methods. The results showed that phytoplankton were sensitive to 17β-estradiol (E2β) pollution, with a concentration of 50, and 100 ng/L E2β exposure promoting the growth of cyanophyta and chlorophyta in the short term; this poses an ecological risk of inducing algal blooms. E2β of 1000 ng/L exposure led to cross-effects of estrogenic effects and toxicity, with most phytoplankton being inhibited. However, small filamentous cyanobacteria and diatoms exhibited greater tolerance; Melosira sp. even exhibited "low inhibition, high promotion" behavior. Exposure to E2β reduced the Shannon-Wiener diversity index (H'), Pielou index (J), and the number of dominant algal species (S) in phytoplankton communities, leading to instability in community succession. E2β of 50 ng/L enhanced the expression levels of relevant functional genes, such as ftsH, psaB, atpB, and prx, related to Microcystis aeruginosa. E2β of 50 ng/L and 5 mg/L can promote the transcription of Microcystis toxins (MC) related genes (mcyA), leading to more MC production by algal cells.

Diminishing mangrove forest structures in Davao City, Philippines

The decline of mangrove coverage across the Philippines to 50% of its original coverage in present years has, led to significant reductions of ecological functions to fisheries and benefits to man. The mangrove forest in Davao City was assessed for its taxonomic list, Importance Value Index, abundance and distribution of mangrove regenerations, forest structure, and species diversity status. The study was conducted in Barangay Bunawan, Lasang, Panacan, Matina Aplaya, 76-A, and Bago Aplaya. All data were gathered by establishing sampling plots (10m x 10m) using the modified transect-plot method. Overall, a total of 34 mangrove species were listed, of which 21 were identified as true mangroves and 13 as mangrove associates. The 21 mangrove species were very low in species richness (54%). Importance Value Index showed that Avicennia marina, Rhizophora apiculata, and Sonneratia alba, respectively, as dominant mangrove species. The mangrove regenerations were in poor condition (<0.50) while relative abundances of growth stages consisted of mature stands at 46.04%, saplings with 27.78%, and seedlings with 26.18%. General diversity indices obtained a low value on the Shannon-Wiener diversity index (H'=1.42) and an average value on the species evenness index (E=0.61), all indicating stressful and unstable mangrove forests. Thus, the mangrove forest ecosystem has imbalances and eventually, only certain species would survive.

Assessing the mangrove community structure and aquatic environmental factors of the mangrove ecosystem in Jangkaran Village

Coastal areas have the potential for damage caused by abrasion, strong winds, and tsunamis. Seeing the high potential for damage that might occur, the appropriate approach is to conserve mangrove forests, one of which is found in Jangkaran Village, Temon District, Kulon Progo Regency. This study aims to identify mangrove community structure and aquatic environmental factors in Jangkaran Village. Mangrove community structure was analyzed using the importance value index and the Shannon-Wiener diversity index. Aquatic environmental factors were analyzed using temperature, pH, dissolved oxygen, and salinity parameters. Data collection was carried out in three locations in Jangkaran Village. Mangrove vegetation data were taken from each transect using the 10 m x 10 m quadrat transect method. Data on aquatic environmental factors were taken directly at the location using a refractometer, DO meter, and pH meter. The results of this study are species with the highest importance index value in location 1, namely Rhizophora apiculata (117.094%), location 2, Avicennia marina (207.203%), and location 3, Avicennia marina (97.0362%). Shannon Wiener diversity indexes in the three locations are 0.6943, 0.4056, and 0.6841. The results of measurements of aquatic environmental factors are temperature 25.7-30.3 °C; pH 7.2-7.7; salinity 25-34; and dissolved oxygen 6.5-6.7. Thus mangrove diversity in Jangkaran village is included in the low category and the aquatic environmental factors is favorable for mangrove growth so that the mangrove ecosystem can be further developed.

Dynamics of weeds and main pests in different rice planting systems supplemented with biodecomposer

Biodecomposers are used as an alternative in pest and weed management by utilizing antagonistic microbes. This study aimed to identify the optimal treatment for suppressing weed growth and controlling the main rice pests, promoting environmentally friendly agricultural practices. Observations were made on three phases of rice growth on land that used biodecomposer and did not use biodecomposer. Weed sampling used a quadrant, which represents each treatment. All weeds were analyzed for density and summed dominance ratio. Pests were observed from the sweep net method. Pests were analyzed with the Shannon-Wiener diversity index (H’). Ten species of weeds are found; the most common and dominant was Cyperus difformis, while the least were Ipomoea aquatica and Ludwigia octovalvis. There were seven pest species; the most common was Nephothettix virescens, while the least was Valanga nigricornis. Using bio-decomposers combined with a two-row planting system was effective in suppressing the development of weeds and pests with a decreasing trend as the rice growing phase increases. Biodecomposers are environmentally friendly even though the process is slow, and have the potential to reduce weeds and pests.Keywords: biodecomposers, Jarwo 2:1, Tegel, trichoderma

Impacts of Soil Properties on Species Diversity and Structure in Alternanthera philoxeroides-Invaded and Native Plant Communities.

Soil properties can affect plant population dynamics and the coexistence of native and invasive plants, thus potentially affecting community structure and invasion trends. However, the different impacts of soil physicochemical properties on species diversity and structure in native and invaded plant communities remain unclear. In this study, we established a total of 30 Alternanthera philoxeroides-invaded plots and 30 control plots in an area at the geographical boundary between North and South China. We compared the differences in species composition between the invaded and native plant communities, and we then used the methods of regression analysis, redundancy analysis (RDA), and canonical correspondence analysis (CCA) to examine the impacts of soil physicochemical properties on four α-diversity indices and the species distribution of these two types of communities. We found that A. philoxeroides invasion increased the difference between the importance values of dominant plant species, and the invasion coverage had a negative relationship with the soil-available potassium (R2 = 0.135; p = 0.046) and Patrick richness index (R2 = 0.322; p < 0.001). In the native communities, the species diversity was determined with soil chemical properties, the Patrick richness index, the Simpson dominance index, and the Shannon-Wiener diversity index, which all decreased with the increase in soil pH value, available potassium, organic matter, and ammonium nitrogen. However, in the invaded communities, the species diversity was determined by soil physical properties; the Pielou evenness index increased with increasing non-capillary porosity but decreased with increasing capillary porosity. The determinants of species distribution in the native communities were soil porosity and nitrate nitrogen, while the determinants in the invaded communities were soil bulk density and available potassium. In addition, compared with the native communities, the clustering degree of species distribution in the invaded communities intensified. Our study indicates that species diversity and distribution have significant heterogeneous responses to soil physicochemical properties between A. philoxeroides-invaded and native plant communities. Thus, we need to intensify the monitoring of soil properties in invaded habitats and conduct biotic replacement strategies based on the heterogeneous responses of native and invaded communities to effectively prevent the biotic homogenization that is caused by plant invasions under environmental changes.

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.

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.

Konservasi Kupu-Kupu Penting Sebagai Penyerbuk di Kampung Wisata Isyo Hills Rhepang Muaif Nimbokrang, Kabupaten Jayapura

Butterflies are an important example of pollinating insects of the Order Lepidoptera. The presence of butterfly pollinating insects in nature is highly dependent or influenced by the availability of flowering plants visited in the ecosystem. The purpose of this study was to determine the diversity and abundance of butterfly pollinator in flowering plants. A direct survey method (visual) with a radius of ± 100-250 m² was done with scan sampling technique. Parameters measured were the abundance and the species richness of butterflies visited flowering plants as well as the species richness of flowering plants visited by butterflies pollinator. The data obtained were analyzed using the the Shannon-Wiener diversity index (H’). The results showed that at study sites in secondary forest habitats and yards, 25 species of butterfly pollinators were found consisting of 5 families with 308 individuals. Nine species of flowering plants visited by butterfly pollinators. The Jatropha integerrima was the most visited by butterfly pollinators with 11 species, followed by Hibiscus rosa-sinensis and Ixora coccinea (9 species), Clerodendron paniculatum (6 species), Mussaenda ralateensis (4 species), Bidens pilosa and Celosia argentea (3 species), Zinnia elegans visited by 2 species and Portulaca oleracea visited by 1 species of butterfly pollinators. Based on the calculation, the value of Shannon-Wiener index (H') is 2.946, which indicates that the level of diversity of butterfly pollinators in the medium category.

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.

Integrated evaluation of the impact of water diversion on water quality index and phytoplankton assemblages of eutrophic lake: A case study of Yilong Lake

Water diversion has been widely utilized to enhance lake water quality and mitigate cyanobacterial blooms. However, previous studies have mainly focused on investigating the effects of water diversion on water quality or aquatic ecological health. Consequently, there is limited research investigating the combined impact of water diversion on the water quality and the ecological health of eutrophic lakes, and whether the WQI and phytoplankton assemblages demonstrate similar patterns following water diversion. In this study, the effects of water diversion on the ecosystem health of eutrophic lakes were comprehensively evaluated based on the WQI indices and phytoplankton assemblages during the NWDP-21 and WDP-22. The results showed that the annual mean of WQI increased from 52.02 to 54.36 after water diversion, which improved the water quality of the lake, especially NH3–N and TN decreased by 58.6% and 15.2%, respectively. The phytoplankton assemblages changed significantly before and after water diversion, and we observed that the total biomass of phytoplankton decreased by 12.3% and phytoplankton diversity indices (Shannon-Wiener diversity, Pielou evenness, and Simpson index) increased by 8.6%–8.9% after water diversion, with an improvement in the connectivity and stability of the phytoplankton. Notably, enhanced adaptations of rare sub-communities for resource use in water diversion environments, and water diversion inhibited the dispersal ability of dominant functional groups, and the effects of hydrological disturbances on the structure of phytoplankton assemblage favored the ecological health of eutrophic lakes. VPA analysis further reveals that water diversion alters the drivers of phytoplankton functional group biomass and phytoplankton diversity. The results of the PLS-PM analysis clarify that water diversion indirectly impacts the total phytoplankton biomass and phytoplankton diversity primarily by modifying light availability. Significant correlations are observed between the dominant functional groups biomass and diversity indices of WQI. The trends in changes observed in water quality indices and phytoplankton following water diversion align with the evaluation of water ecological health. This study provides valuable guidance for the ecological management of the diversion project in Yilong Lake and serves as a reference for similar projects in other lakes.

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.

Mollusca Biodiversity as A Quality Bioindicator Waters in Central Lombok Gerupuk Bay Coastal Area

Various natural resource utilization activities on the coast of Gerupuk Bay can potentially affect the quality of the aquatic environment, both biotic and abiotic, one of which is mollusc biodiversity. This study aimed to determine the relationship between the existence of Mollusca biodiversity and water quality and substrate in Gerupuk Bay. This study used a quantitative descriptive method of determining stations using the purposive sampling method based on differences in community activities at each station. Sampling was conducted at three stations, including Mollusca samples and water quality measurements: salinity, pH, temperature, and substrate. Molluscs in Gerupuk Bay found 55 species of Mollusks representing three classes, namely the Gastropoda class, with as many as 44 species incorporated in 22 Families; the Bivalve class, as many as ten species contained in 6 Families; and the Scaphopoda class, with as many as one types incorporated in 1 Family. The composition of Mollusca classes found on the Gerupuk Bay Coast is Gastropoda class at 62%, Bivalve class at 35%, and Scaphopoda class at as much as 3%. Mollusca diversity is calculated using the Shannon-Wienner diversity index (H'). The diversity index results ranged from 2.890-1.998, with moderate categories at all stations. Bioindicators of water quality using the diversity index show that stations I and III categorize the Gerupuk Bay area as lightly polluted. In contrast, at station II, it is moderately polluted.

Populasi dan Keanekaragaman Fungi Mikoriza Arbuskular pada Rizosfer Tanaman Lada (Piper nigrum L.) Monokultur dan Polikultur

Arbuscular mycorrhizal fungi (AMF) is a type of fungus that comes from the endomycorrhizal group, these fungi have the ability to form symbiosis with almost 90% of higher plant species. Population and diversity of AMF are influenced by biotic factors and abiotic factors. This research aims to determine the differences in population, diversity and dominant types of AMF in the rhizosphere of pepper planted in monoculture and pepper in polyculture. The soil samples were taking from monoculture and polyculture pepper plantations in Air Naningan District, Tanggamus Regency. The AMF population was tested using the One way Annova test. Culture trapping was done using a factorial treatment with the first factor being the origin of the soil sample (K) and the second actor being the type of host plant (T). Treatments design used was randomize design (CRD). The results showed that the AMF population in polyculture pepper plantation soil samples was higher than monoculture pepper, based on the Shannon-Wiener Diversity Index, AMF diversity in monoculture pepper and coffee intercropping pepper plantations was higher than in cocoa intercropping pepper plantations, and the type of AMF was dominant. from the results of trapping culture with monoculture pepper garden soil samples, namely spores of the species code S7, in samples of coffee intercropping pepper plantations the code S7 is dominant, while in cocoa intercropping pepper plantations it is dominated by code S6. Keywords: Arbuscular mycorrhizal fungi, diversity, population.

Population Abundance and Frequency of Visits Forcipomyia spp. (Diptera: Ceratopogonidae) on Cocoa Plantations in Lima Puluh Kota District, Indonesia

Forcipomyia spp. is a pollinator insect on cacao plants that belongs to the Ceratopogonidae Family, Diptera Order. The objectives of this research were to determine the abundance of the insect population of Forcipomyia spp. in Lima Puluh Kota District and to determine the frequency of visits of those insects to cacao flowers. This research was conducted on a small smallholder plantation in Sungai Talang Village, Lima Puluh Kota District. Then, the samples obtained were identified at the Andalas University Laboratory. This research was conducted using a survey method and purposive sampling technique. Five cacao plants were selected in each plot of land, and then three flower beds per plant were selected to bloom. Sampling was carried out by installing yellow sticky traps. The insects obtained were put into a collection bottle filled with 96% alcohol to preserve those insects, and then the abundance of Forcipomyia spp. Insects were calculated. The research results showed that the highest insect abundance was in Jorong Guguak Nunang: 1.260 individuals, then in Jorong Bukik Apik: 1.061 individuals and the lowest was in Jorong Boncah: 1.045 individuals. The highest frequency of visits was in the morning, with an average of 648 individuals/60 minutes. The insect diversity index based on the Shannon-Wienner Diversity Index in Jorong Guguak Nunang was 1,97; in Jorong Boncah, it was 2,21; in Jorong Bukik Apik was 1,88, and all of it is in the medium diversity level category.

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.