Shannon-Weiner Diversity Index Research Articles

Comparison of avian species diversity and abundance in relation to habitat structure: toward using birds as indicators of ecosystem health at zone 8, Lokoja, Kogi State, Nigeria

Avian species in relation to plant community can be used to determine the health status of the ecosystem. Habitat destruction can lead to extinction of many bird species as well as other plant communities. The study was conducted for three (3) months to determine the variation in avian species diversity and abundance in four different adjacent habitat structures: Farmland, Gallery Forest, Rocky Outcrops and Uncultivated Grassland, all located at Zone 8 area of Lokoja, Kogi State. The Line Transect method was used to collect data from the entire study area where 2000 m transect was marked and further divided into short sections of 100m with 50m distance apart. Each marked section was sampled ten (10) times from 6:30 am to 10:00 am. Birds’ species encountered were identified using the field guide and songs. Species diversity was determined using the Shannon-Weiner diversity index (H). The study recorded a total number of 4,490 individuals of 110 species belonging to 32 families. Farmland had the highest number of individuals with a total of 1,228 individuals belonging to 92 species, followed by the Gallery Forest with a total of 652 belonging to 95 species, followed by uncultivated grassland with a total of 339 individuals belonging to 65 species and the Rocky outcrop with a total of 122 individuals belonging to 55 species. Bird species abundance between the habitat types differ significantly (p<0.05). The Gallery Forest was the most diverse in bird species with a mean diversity index (H=3.55), though diversity between the habitat was not statistically different (p>0.05). The findings from this study indicate that Zone 8 is rich in avian species diversity. Therefore, there is need to conserve this area from activities that might contribute to habitat loss, which can lead to extinction of some bird species and possibly plants community in the nearest future.

Phytoplankton Community Diversity and Its Environmental Driving Factors in the Northern South China Sea

The South China Sea (SCS) plays an important role in global marine ecology. Studies of phytoplankton diversity promote the sustainable utilization of resources in the SCS. From July to August 2020, the phytoplankton community structure at 47 stations in the northern SCS was investigated. Species composition and distribution of phytoplankton, water quality, diversity index, main influencing factors, and succession characteristics of the community structure were analyzed in combination with the survey results from previous years. A total of 332 separate taxa from 83 genera and three phyla were identified, including 142 species and 45 genera of Bacillariophyta, 188 species and 36 genera of Dinophyta, and two species and two genera of Chrysophyta. Average phytoplankton cell abundance was 649.97 cells/L. Nitzschia spp., Thalassionema nitzschioides, and Scrippsiella spp. were the dominant species. Scrippsiella spp. was found for the first time as a dominant species in the northern SCS. Meanwhile, Nitzschia spp. was associated with organic-polluted water. The high-value areas of Nitzschia spp. also indicated eutrophication, and water was slightly polluted. The Shannon–Weiner diversity index of the surface layer was 0.99–4.56 (with a mean of 3.57), and the evenness index was 0.23–0.96 (with a mean of 0.83). The phytoplankton community structure in the northern SCS was deemed to be stable. Pearson correlation analysis showed that the sum of nitrate and nitrite was significantly negatively correlated with the abundance of dinoflagellate, which indicated restrictions as a result of the sum of nitrate and nitrite, with no significant correlation between ammonium salt and various groups. Small- and medium-sized phytoplankton are usually dominant in the SCS, where nitrogen is limited.

Seasonal Diversity and Occurrence of Filamentous Fungi in Smallholder Dairy Cattle Feeds and Feedstuffs in South Africa.

This study investigated 65 (35 in summer and 30 in winter) smallholder dairy cattle feeds from Free State and Limpopo provinces in South Africa from 2018 to 2019 for fungal contamination and assessed the impacts of seasonal variation on fungal contamination levels, isolation frequency, and diversity. Samples were examined for fungal contamination using macro- and microscopic approaches, and their identities were confirmed by molecular means. A total of 217 fungal isolates from 14 genera, including Aspergillus, Fusarium, and Penicillium, were recovered from feeds from both seasons. The most prevalent fungal species recovered were A. fumigatus and P. crustosum. Mycological analyses showed that 97% of samples were contaminated with one or more fungal isolates, with the summer fungal mean level (6.1 × 103 to 3.0 × 106 CFU/g) higher than that of feeds sampled during winter (mean level: 1.1 × 103 to 4.1 × 105 CFU/g). Independent sample t-test revealed that the isolation frequencies of the genera Aspergillus and Fusarium were significantly (p ≤ 0.05) higher in summer than winter, while Penicillium prevalence in both seasons was not statistically (p > 0.05) different. Furthermore, the Shannon-Weiner diversity index (H') revealed a higher fungal diversity in summer (H' = 2.8) than in winter (H' = 2.1). This study on fungal contamination could be used for future fungal control and mycotoxin risk management in South Africa.

Behavioural Impact of Captive Management Changes in Three Species of Testudinidae

Reptile behaviour and welfare are understudied in comparison with mammals. In this study, behavioural data on three species (Astrochelys radiata, Stigmochelys pardalis, Aldabrachelys gigantea) of tortoises were recorded before and after an environmental change which was anticipated to be positive in nature. The environmental changes differed for each population, but included a substantial increase in enclosure size, the addition of substrate material, and a change in handling procedure. A tortoise-specific ethogram was created to standardise data collection. Focal behaviour sampling was used to collect behavioural data. Changes in the duration of performance of co-occupant interaction and object interaction in the leopard (Stigmochelys pardalis) and Aldabra (Aldabrachelys gigantea) tortoises were observed following the environmental changes. The Shannon–Weiner diversity index did not yield a significant increase after the changes but had a numerical increase which was relatively greater for the leopard tortoise group, which had experienced the greatest environmental change. The leopard tortoises also demonstrated changes in a greater number of behaviours compared to the other species, and this was sustained over the study period. However, this included a behaviour indicative of negative affect: aggression. Whilst we are unable to conclude that welfare was improved by the management changes, there are suggestions that behavioural diversity increased, and some promotion of positive social behaviours occurred.

EDAPHIC INFLUENCES ON TREE SPECIES COMPOSITION AND COMMUNITY STRUCTURE IN A SECONDARY-LOWLAND DIPTEROCARP FOREST OF KOTA DAMANSARA FOREST RESERVE, SELANGOR

This research was conducted to determine tree species composition and its relationship with edaphic factors at Kota Damansara Forest Reserve (KDFR), Selangor. Ten study plots of 25 m × 20 m each were established randomly covering a total area of 0.5 ha. In each plot, all trees with diameters at breast height (DBH) of 5 cm and above were tagged and measured whilst topsoil samples at 10 cm depths were taken for their physical and chemical properties. A total of 205 trees from 46 species and 22 families were recorded in KDFR. As for species diversity, the forest showed a Shannon-Weiner Diversity Index (H’) of 3.43 and an evenness value of 0.89 which portrays the uniformity of tree species distribution in the study site. The soil analysis in this study demonstrated that KDFR was dominated by sandy clay texture with organic matter content ranging from 3.94% to 14.24% and acidic soil pH of 3.86. Redundancy analysis indicated that Cinnamomum iners, Cratoxylum arborescens, Myristica cinnamomea, and Syzygium grandis were closely related to soil chemical properties such as nutrients of Ca, P, K. Data and information from this study are crucial as a guideline for future ecological research in tropical forest areas.

Abundance of invasive alien species of teklan (Ageratina riparia (Regel) R. M. King & H. Rob.: Asteraceae) on floor vegetation in “Eka Karya” Botanical Garden, Bali

Ageratina riparia is an invasive alien species that get a particular attention in “Eka Karya” Bali Botanical Garden. This study aims to determine the abundance of invasive alien species A. riparia on forest floor vegetation in “Eka Karya” Bali Botanical Garden, and the factors that influence its abundance. Ageratina riparia is an invasive herb that can disrupt the balance of the ecosystem. The advantages of this plant in reproducing and adapting to the environment, make this plant very easy to grow and develop in a habitat. The purposive sampling method was used with the plot that placed systematically. The research area divided into five research stations with 10 plots (2 x 2 m) for each station. Vegetation data were analyzed to determine the density, relative density, frequency, relative frequency, and important value index (INP), then completed with Shannon-Weiner diversity index (H'), dominancy index (C), evenness index (E) and visualization abundance of species A. riparia of with Non-metric Multi Dimensional Scaling (NMDS). Environmental data is calculated analyses in Detrended Correspondence Analysis (DCA). The results showed that A. riparia at station 1 (Kawasan Kepala Burung) had an INP of 62.50%, station 2 (Taman Usada) with an INP of 52.40%, station 3 (Taman Cyathea) with an INP of 89.09%, station 4 (middle open area) with an INP of 110.25%, and the highest is at station 5 (Taman Upacara Panca Yadnya) with an INP value of 118.92%. The presence of A. riparia can be influenced by all environmental factors measured such as air humidity, soil moisture, soil pH, air temperature and soil temperature, altitude, land slope, and light intensity.

Assessment of freshwater plant diversity and local difference in freshwater plant use knowledge in Punakha district, Bhutan

Freshwater plants play a paramount role in an aquatic ecosystem. However, only limited studies have been carried out on freshwater plants. Therefore, the study aimed to assess the diversity of freshwater plants in different freshwater bodies of Punakha District, the correlation of freshwater plant species with the environmental variables, and the local community difference in freshwater plant use knowledge in Punakha district. A total of 20 water bodies were selected using a stratified sampling method. Area-based surveys were employed to assess the plant species from a total of 80 plots, each with the quadrat of 5 m x 5 m. Environmental variables such as altitude, water depth, water velocity, temperature, precipitation and evapotranspiration were measured. The study recorded a total of 72 freshwater plant species distributed among 57 genera and 37 families. Shannon-Weiner diversity index revealed high diversity of freshwater plants from ponds (H’ = 3.3) followed by ditches (H’ = 3.16), streams (H’ = 3.07) and lakes (H’ = 2.83). The study revealed the decrease of freshwater plant species with an increase in the water velocity, depth and altitude. There was a significant association between respondents’ freshwater plant use knowledge with gender (x2 (1) = 6.04, p = .014), age (x2 (1) = 13.21, p = .000) and education level (x2 (1) = 4.53, p = .003). Females and illiterate respondents with aged 31 years old and above had more knowledge on freshwater plant use compared to males and educated respondents with aged 30 years old and below.

Soil meso- and micro-fauna community in response to bamboo-fungus agroforestry management

Bamboo-fungus agroforestry management is an ecological model of sustainable production of moso bamboo forest, and Stropharia rugosoannulata has been widely planted in moso bamboo forest. However, little attention has been paid to soil fauna community in bamboo-fungus agroforestry system. Thus, the aim of this study was to investigate the response of soil fauna communities to agroforestry management, and to explore the relationships between soil fauna communities and soil properties. An experiment with 0, 1, 2 and 3 years of planting was carried out in an existing moso bamboo forest. The community composition of soil meso- and micro-fauna was investigated, and the soil properties were determined. Results showed that a total of 2968 individuals of soil meso- and micro-fauna, belonging to 8 classes and 13 groups were detected. The group number and density of soil fauna was highest right and then decreased. Planting Stropharia rugosoannulata in moso bamboo forest increased the density of dominant groups, but did not change its composition. Shannon-Weiner diversity index (H), Margalef richness index (D) and Density-Group diversity index (DG) were the highest one year after planting the fungus, while Simpson dominance index (C) was the lowest in the meantime. Contents of soil moisture (SMC), organic matter (SOM), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) increased first and then decreased with the increase of planting years, peaking at 1 year after planting, while the pH value continued to increase. Responses of soil fauna community were associated with soil physicochemical properties. Redundancy analysis (RDA) showed that SOM was the main environmental factor driving the variation of soil fauna community, followed by TP and TN. In conclusion, planting Stropharia rugosoannulata in moso bamboo increased the diversity and abundance of soil fauna communities due to its contribution to abundance of organic matter and supply of nutrients.

AN INVENTORY OF DIVERSITY OF BUTTERFLY SPECIES IN LUCKNOW REGION OF NORTHERN INDIAN PLAIN

Butterflies are more elegant and appealing than most insects, they are included in the order Lepidoptera. They are varied in shape, size and colour. They are found everywhere throughout the world apart from the poles. The present study aims to provide a baseline for the analysis of population status of butterfly species and their dispersion in Lucknow region. The butterfly individuals were collected randomly for twelve consecutive months, August 2021 to July 2022. The butterfly data was collected by using the photographic evidences, capture and release method as well as by visual observations. The butterfly diversity was determined to quantify the values of Shannon diversity index (H) and Simpson diversity index (D). Notably, 40 species of butterfly of 5 families and number of individuals of each species were monthly recorded during the entire period. Overall, this site showed higher diversity of butterfly species. In this region, the Shannon-Weiner diversity index (H) and Simpson diversity index (D) were measured 3.652 and 0.974, respectively. The identified butterflies in the campus are from families Nymphalidae (20 species), Pieridae (8 species), Hesperiidae (5 species), Lycanidae (4 species) and Paplionidae (3 species). The findings showed a marked diversified pattern of butterfly species. This may be attributed to the more diverse habitats in Lucknow region.

Biodiversity and Structure of Rotifera Communities in the Great Garraf Drain Channel, Southern Iraq

Three sites, selected on the Great Garraf Drain Channel (GGDC) demonstrated the first ever study dealing with rotifers biodiversity features from August 2019 till July 2020. Seventy-two taxonomic units were identified. The high densities of rotifera ranged from 733.32 - 32300 Ind./m3. Brachionus urceolaris, Keratella quadrata (long spin), Keratella quadrata (short spin) and Syncheta obloga were the most common relative abundance recorded in the index. In contrast the results of the constant index showed that there were nine constant taxonomic units. The species richness index was recorded from 1.489- 6.900. Jaccard presence similarity index revealed a strong link between stations 2 and 3 with a value of 83.30%. Hereinafter Shannon-Weiner diversity index recorded values ranging from 0.821-2.901 bit/Ind. The species uniformity index ranged from 0.296- 0.925. Nevertheless, the values of this index indicated no environmental stress on rotifera assemblage in the river environment. Also, it was concluded that GGDC was considered generally ranging from moderately polluted in some sites to highly polluted water in other locations during the study period.

Community Composition of Beetles (Insecta: Coleoptera) along Elevational Gradients in Phulchowki Hill, Lalitpur, Nepal

Beetles are recognized as important bio-indicators of the ecosystem that can be used to determine species diversity, genetic diversity and ecosystem diversity. We investigated the species composition and diversity of beetles in four seasons along elevational gradients in Phulchowki hill from June 2018 to May 2019. Sampling was done using pitfall traps in five sites located at 1500 m, 1800 m, 2100 m, 2400 m and 2700 m altitude respectively. Overall, we documented 43 morphospecies under 37 genera and 12 families from the study area. Scarabaeidae was the most dominant family whereas Onthophagus sp.2 being the most abundant species in our study. The Shannon-Weiner diversity index, species richness and abundance were highest at 1500 m. Furthermore, diversity and species richness were highest in the spring, whereas peak beetle abundance was observed in summer. Principal component analysis (PCA) was performed to analyze the distribution patterns of the beetle families along the elevational gradients. PCA revealed a strong association of the Carabidae family with 1500 m, 1800 m and 2100 m altitude whereas the Scarabaeidae family were mostly associated with human-influenced areas such as 1500 m and 2700 m altitude. The generalized linear model (GLM) revealed that temperature had a major impact on the overall beetle composition.

Abundance and Diversity of Soil Arthropods in Different Habitats in Chitwan Nepal

Arthropod diversity is generally influenced by the type of habitat in an agro-ecosystem. Crop diversity, soil types, nature of habitats (intensive, semi-intensive and natural), proximity to natural habitats, landscape complexity etc. are the major arthropod diversity influencing factors. Hence, this study was designed to investigate the diversity of various arthropod species among different habitats such as mango orchard, litchi orchard, vegetable field, organic field and uncultivated land during March 2021. Arthropod sampling was taken on every three- day interval using pitfall trap. The composition, relative abundance, and diversity indices of the arthropods of five different habitats were analyzed. Maximum abundance was recorded in uncultivated land (N = 398) and minimum in the vegetable field (N = 61). Shannon-Weiner Diversity Index (1.76) and species richness (9.67) were found highest in mango orchards. The greatest evenness was recorded in the vegetable field (0.91) and more dominance index was recorded in uncultivated land (0.60). There was a significant difference in total abundances of arthropods between vegetable fields than in the organic and uncultivated fields, being highest in uncultivated land followed by litchi, mango and organic field. Hymenopterans were the most abundant order (53.55%) followed by Coleoptera and Arachnida. These arthropods were crop pests and beneficial. Beneficial arthropods population was more than crop pests. Such beneficial arthropods play a vital role to deliver an ecosystem service. This study can help to develop a conservation and management protocol for beneficial arthropods in the agro-ecosystem.

Developing microsatellite duplex PCR reactions for sterlet (Acipenser ruthenus) and their application in parentage identification

The sterlet (Acipenser ruthenus) is one of the 27 sturgeon species and is well-known for its wide distribution and small body size in comparison to other sturgeons. For assessing the population genetics and parentage identification of sterlet, ten microsatellites developed for Chinese sturgeon and cross-amplified in sterlet were tested by 40 individuals of sterlet. The ten microsatellites were developed using transcriptome sequencing of Chinese sturgeon. The expected heterozygosity (HE), observed heterozygosity (HO), Shannon-Weiner diversity indices (H′) and polymorphic information content (PIC) of the 10 microsatellites ranged from 0.466 to 0.751, from 0.438 to 0.938, from 0.66 to 1.51 and from 0.368 to 0.716, respectively. Combined exclusion probability based on the genotype of pair parent known (CE-PP), one parent known (CE-2P), and no parent known (CE-1P) of the 10 microsatellites were 99.99%, 99.96%, and 99.49%, respectively. These result showed that the 10 microsatellites should be helpful for assessing the population genetics and parentage identification of sterlet.

Diversity and Regeneration Potentials of Some Non-Timber Forest Product Species (NTFPS) in Bagale Hill Forest Reserve, Girei Local Government Area of Adamawa State

This study assessed diversity and regeneration of some Non-Timber Forest Products (NTFPs) species in Bagale Hills Forest Reserve Girei Local Government Area of Adamawa State, Nigeria. Parameters evaluated included; species diversity of NTFPs in the study area and regeneration potentials of NTFPs in the study area. A sampling design consisting of an approximately 250m baseline and 5 transects of 20m was used. Thus, all NTFPs individuals, from seedlings to adult individuals, of each species were recorded and their DBH measured. The distance between consecutive transects was 50m. Diversity indices and Importance Value Index (IVI) of the species were determined using relevant formulae. One-way Analysis of Variance (ANOVA) was used to compare results of Shannon Weiners Diversity Indices amongst transects and amongst tree, sapling and seedling species. The results of tree, saplings and seedling species in study site revealed 12, 9 and 10 species respectively. The individual trees, saplings and seedlings species were 41, 39 and 53 belonging to 7 families in the study site respectively. Analysis of Variance (ANOVA) indicated that there was no significant difference in Shannon Weiners Diversity Indices among tree, sapling and seedling species in the forests (p ≥ 0.05). Results show species of NTFPs tree which included; Annona senegalensis, Adansonia digitata, Bombax Costatum, Detarrium microcarpum, Haematostaphis barteri, Hexalobus monopetalus, Parkia biglobosa, Tamarindus indica, Ximenia americana, Vitellaria paradoxa, Ziziphus Mauritania and Ziziphus spina-christi. The families with the highest number included Annonaceae, Fabaceae and Rhamnaceae which had 2 species each. Vitellaria paradoxa, Annona senegalensis and Tamarindus indica were the most abundant in Transects I-III, while Parkia biglobosa, and was the most abundant in Transects IV-V. Vitellaria paradoxa, Annona senegalensis, Tamarindus indica and Parkia biglobosa are further shown to have the highest Importance Value Index in all Transects. Results further showed saplings species as they occurred in all the Transects with Vitellaria paradoxa, Annona senegalensis and Detarrium microcarpum as the most abundant saplings species and highest Importance Value Index. Results showed seedling species of NTFPs encountered in all transects in which Hexalobus monopetalus, Ziziphus Mauritania and Detarrium microcarpum occurred as the most abundant seedling species. Shannon-Weiner (H´) Diversity Indices were; H´ = 1.16223, H´ = 0.86756, H´ = 1.62602, H´ = 1.05492 and H´ = 1.32966 in the respective transects. Shannon-Weiner (H´) Diversity Indices of all NTFPs trees, saplings and seedlings were; trees H´ = 2.39016, saplings H´ = 1.70359 and seedlings H´ = 1.86854 respectively.

Diversity of Natural Enemies Associated with Lac Insect <i>Kerria lacca</i> (Kerr) in Punjab

A survey was conducted to record the diversity of lac insect Kerria lacca (Kerr) associated natural enemies (predators/ parasitoids) during 2019-2020. In katki crop, the abundance of natural enemies ranged from 1.08 to 44.09%. There were three parasitoids viz, Parechthrodryinus clavicornis (Cameron) (1.08%), Aprostocteus purpureus (Cameron) (26.88%), Tachardiaephagus tachardiae somervilli (2.15%); and two predators; Chrysoperla zastrowi sillemi (5.38%), Eublemma amabilis (44.09%) and only one hyperparasitoid viz; Bracon greeni (Ashm.) (20.43%). Shannon-Weiner diversity index, evenness index and dominance index for natural enemies was found to be 0.67, 0.80 and 0.20. In baisakhi crop, the abundance ranged from 6.56 to 45.90% with maximum abundance of predator E. amabilis (45.90%) and the least of parasitoid T. tachardiae How. (6.56%); and the Shannon-Weiner diversity index, evenness index and dominance index was 0.65, 0.77 and 0.23, respectively.

Diminutive Freshwater Fish in the Santa CruzRiver System, Laguna, Philippines

Diminutive freshwater fishes are small vertebrate species, maturing at sizes equal or less than 50-100 mm. The distribution and diversity status of these fishes are poorly known because they are difficult to observe in the wild due to their small size and remote location, especially in selected crater lakes, mountain streams, and waterfalls. The study provides baseline data for the diminutive freshwater fishes in the Santa Cruz River System in Laguna, Philippines. The survey was conducted in the upstream, midstream, and downstream for three quarters in 2016-2017. A total of 1,474 individuals belonging to nine families, 12 genera and 15 species were collected. Of the nine families, Gobiidae was the most abundant (47%) followed by Poeciliidae (18%) and Eleotridae (11%). Shannon-Weiner diversity indices ranged from 0.59 to 1.73. Dominance and Evenness ranged from 0.20 -0.75 and 0.23 to 0.99 respectively. The study recommends preventive approaches over restorative actions for the conservation and protection of the diminutive fishery resource.

Investigation and Analysis of Plant Species Richness at Danzhou Campus of Hainan University

Campus vegetation is an important part of the campus environment, and the construction of an ecological campus is an essential component of campus development. A field survey and diversity analysis of woody plants and herbaceous plants of Danzhou Campus, Hainan University was conducted. The results showed that there are 67 species of woody plants on campus, belonging to 34 families and 58 genera, with Shannon-Weiner diversity indices ranging from 1.5596 to 3.0824, the Simpson’s indices ranging from 0.7031 to 0.9442, and the Pielou’s evenness indices ranging from 0.2960 to 0.4807. This paper aims to provide feasible references and suggestions for the plant configuration of Danzhou campus of Hainan University.

Ecology of morphological fruit types, and fruit and seed colors in 27 Venezuelan plant communities

The composition, richness and diversity (Shannon-Wiener index) of morphological fruit types, and fruit and seed colors were assessed in 27 Venezuelan plant communities. We examined whether morphological fruit types and fruit and seed colors represent ecological attributes with predictable values that can be related to the structural and climatic characteristics of plant communities. Texture, dehiscence, and fruit types following two classification systems, and fruit and seed colors were determined for each plant community and habitat. The highest mean frequencies of dry fruits were found in the meadow, wetland and shrubland vegetation types, and the highest mean frequencies of fleshy fruits in the wet forests. The frequencies of dry and fleshy fruits, and dehiscent and indehiscent fruits were largely similar in both habitat types. The most common fruit types were loculicidal and septicidal capsules in the mesothermic shrublands, wetlands, and savanna grassland; berries in the cloud forests, sub-páramo and riparian wet forest; drupes in the cloud forests and psammophilous meadow; schizocarps in the xerophytic shrublands and psammophilous meadow; and achenes in the savanna grassland and páramo. The richness and diversity of the morphological fruit types, and fruit and seed colors identified were highest in dry forests. Almost all the ecological parameters measured were positively correlated, including plant species number, except abiotic factors. The composite Shannon-Weiner diversity index and fruit types and fruit and seed colors richness were significantly correlated with the total number of plant species number. Plant locality classification according to the frequencies of each morphological fruit type showed approximate affinities with geographic areas, vegetation type and plant community. This suggests a predictable value, and highlights the importance of the composition, richness, and diversity of fruit types in the organization of plant communities and their biotic and abiotic interactions.

Diversity and Structure of Demersal Fish Community Over the Northern Slope in the South China Sea

Three bottom trawl surveys over the northern continental slope in the South China Sea (18°50′–20°40′N, 112°50′–115°10′E) were carried out, in June 2015, March 2017 and September 2018, to investigate species composition, biodiversity and community structure of demersal fish. Surveys in 2015, 2017 and 2018 captured 97 fish species (representing 77 genera, 52 families, 26 orders), 108 fish species (representing 84 genera, 61 families, 19 orders) and 126 fish species (representing 105 genera, 74 families, 25 orders), respectively. Three surveys captured a total of 252 fish species, representing 164 genera, 97 families, 30 orders. Perciformes dominated. Species richness in station linking shallow continental shelf with deep slope was the lowest among stations. In three surveys, 16 species occurred in the catches of three surveys, accounting for 6.35% of all species. Species replacement rate between stations showed a significant linear relationship with the depth difference and latitude difference. Margalef’s species richness index (D), Shannon–Weiner diversity index (H’) and Pielou’s evenness index (J’) among stations ranged 2.65–6.74, 1.02–4.15 and 0.28–1.14, respectively. Differences of D, H’ and J’ were insignificant among seasons. There were significant positive linear relations between H’ and J’ and latitude. D, H’ and J’ decreased with increasing sampling depth, however the relations were not significant. Based on multivariate statistical analysis, fish community at species level was divided into five groups with average dissimilarities of 95.69%–99.96%. In terms of genus and family, average dissimilarities among groups were more than 88.11% and 82.69%. There were significant differences in species composition between depths, but no significant differences between seasons and temperatures, as well as in genus and family composition.

The abundance of arthropods and natural enemies on two growth phases of hybrid corn, Solok District, Indonesia

Abstract. Hervani D, Sari SP. 2022. The abundance of arthropods and natural enemies on two growth phases of hybrid corn, Solok District, Indonesia. Biodiversitas 23: 2966-2972. Solok District, West Sumatra, Indonesia is one of Indonesia's hybrid corn production regions. As yet, the study of arthropods is still limited. This study aimed to study the abundance and diversity of arthropods in the hybrid maize agroecosystem in Solok District, West Sumatra. The research was conducted from May to November 2020 in Tanah Garam Sub-district, Solok District. The sampling was carried out four times in two growth phases of hybrid corn: vegetative (the age of 20 and 40 days after planting/DAP) and the generative phase (the age of 60 and 80 DAP). The arthropod collection was conducted using a yellow trap and a modified vacuum technique. The identification process was carried out at the Insect Bioecology Laboratory, Andalas University. The study found two classes of arthropods in a hybrid cornfield in Solok District, namely Arachnida and Insecta. The Shannon-Weiner diversity index value (H') was 1.383, and the evenness index of species (J') was 0.997. A total of 2,927 individual arthropods, 80 families, 8 orders, and 3 classes, were recorded in the hybrid corn ecosystem in Solok District. Insect class (2,866 individuals) dominated the diversity of arthropods, where the majority of the arthropods found belong to groups of natural enemies such as predators and parasitoids. Conservation of natural enemies (predators and parasitoids) is one of the main factors in supporting the success of pests biologically, so the act of identifying natural enemies in an area is very important.