Simpson's Diversity Index Research Articles

Floristic Composition and Tree Species Diversity with DBH ≤ 5 cm at Gunung Stong State Park (GSSP), Kelantan, Peninsular Malaysia

A study was conducted to assess the tree species composition, diversity, and above-ground biomass at Gunung Stong State Park (GSSP), Dabong, Kelantan, Malaysia. Five plots were systematically established of each 20 m x 20 m (0.2 ha), and all trees with a diameter at breast height (DBH) of 5 cm and below were enumerated. A total of 273 individual trees were enumerated, representing 88 species belonging to 40 families and 67 genera. Lauraceae was the most represented family, consisting of 3 genera and 4 species. The Shannon-Weiner Diversity Index (H’) indicated a high diversity value of 3.46 and the Simpson Diversity Index (D) with 0.97. The total above-ground biomass of the trees was estimated to be 0.619 ta/ha. Notably, Vatica maingayi and Aquilaria malaccensis identified in the study area are listed as vulnerable, with decreasing population trends. The floristic composition and the presence of these threatened species underscore the ecological importance of GSSP, highlighting its potential role as a critical conservation site for maintaining biodiversity and protecting vulnerable plant species. This study provides valuable baseline data for the management and conservation of forest resources in GSSP and contributes to the broader understanding of tropical forest ecosystems in Malaysia position implies that the study area can serve as a conservation site for the threatened plant species.

Icthyofaunal Diversity in Selected Lakes of Kodagu District

The study was carried out to document the fish diversity in the lakes of Somwarapete taluk of Kodagu district, Karnataka. The study was carried out from June 2021- May 2022. Three Lakes namely, Tavare kere, Dodda kere and Honnamanna kere was selected for the study. The fishes were collected with the help of local fishermen and identified with the help of standard reference material and internet sources. The diversity indices such as Shannon diversity index, Simpson diversity index and Pielou’s evenness index were calculated to understand the diversity and distribution of fish species. A total of 17 species, belonging to 13 genera, and 8 families were documented. On evaluating the endemism of the fishes, it was noted that 23% were endemic to Western Ghats, 59% were endemic to Indian Subcontinent, and 18% were exotic taxa. The study also showed the abundance of family Cyprinidae with 41% of taxa, followed by Channiadae and Claridae with 17 and 12% taxa respectively. Simpson diversity index varied from 0.83 (Honnamanna kere) to 0.9 (Tavare kere and Dodda kere ), indicating a high diversity and Pielou’s evenness with a value of 1 showed that the ecosystem is stable.

Macrofungi diversity in a tropical wet evergreen forest of Eastern Himalayan foothills: A case study of Dihing Patkai National Park, Assam, India

Dihing Patkai National Park (DPNP) is situated in the Tinsukia and Dibrugarh districts of Assam, India. The forest type of the park is Assam Valley Tropical Wet Evergreen Forest (category 1B/C1). In order to explore the fungal diversity, different randomly selected belt transects of size 0.1 ha were laid in the park. Overall, 159 species of macrofungi representing 81 genera, 43 families, 14 orders, 5 classes, and 2 phyla under the kingdom fungi have been recorded from the Park. Maximum species were found in the family Polyporaceae (34 spp.) followed by Mycenaceae (14 spp.), Omphalotaceae (11 spp.), Marasmiaceae (14 spp.), Russulaceae (10 spp.), Tricholomataceae, Hymenochaetaceae, Amanitaceae, Agaricaceae, Xylariaceae (5 spp. each) and so on. The values of the Shannon-Wiener Diversity Index, Simpson diversity index, and Brillouin’s index were found to be 3.54, 0.94, and 3.49 respectively, which means the level of diversity of macrofungi was in the higher category. The evenness index was found to be 0.22 or only 22% of species were common or shared among plots within the DPNP. The four diversity indices proved that the DPNP has high species diversity and a healthy forest ecosystem. Maximum species of macrofungi (22%) were found associated with Dipterocarpus retusus followed by Castanopsis indica (13%), Shorea assamica (11%), Vatica lanceaefolia (9%), Mesua ferrea (8%), and the rest of macrofungal species associated with the plant species ranged from 5% to 1%. The present study is an attempt to document the fungal diversity in the tropical wet evergreen forest of the Eastern Himalayan foothills that will be helpful to the scientific community for further study.

Livelihood Diversification in Rainfed Areas of Telangana State: Evidence from Household Level Survey

Farmers in rainfed agriculture participate in both on-farm and off-farm activities to reduce risks from weather shocks, low farm fragmentation, low soil productivity, and frequent droughts and floods. Dependence on farm revenue alone proved difficult and risky. The study was conducted in 2022 to determine patterns and a livelihood diversification index at the household level for various farm sizes producing the chickpea crop. Primary data were acquired from 80 randomly selected farmer respondents in four mandals of Kamareddy district in Telangana State. Descriptive statistics were applied to characterize the sample households’ demographic, social, and economic factors. The livelihood diversification index was estimated using the Simpson diversity index at the household level. The data revealed that small and marginal farmers have very high diversification levels, while medium and large farmers have high diversification levels. The percentage share of on farm income stands highest for large farmers and lowest for marginal farmers and vice versa about non-farm activity. Regression analysis indicated education, farm size, total on-farm income, and net returns from pulse crops were significant determinants for diversification. The study further suggests that government support needs to focus on the provision of incentives for diversification at both on-farm and non-farm levels.

Biodiversity, distributions and isolation of microplastics pollution in finfish species in the Panjkora River at Lower and Upper Dir districts of Khyber Pakhtunkhwa province of Pakistan.

The basic aim of this study was aimed to determine the ichthyofaunal diversity of River Panjkora in both upper and lower Dir districts in Khyber Pakhtunkhwa province of Pakistan.Fish samples were collected by using fishnets from March to September 2020. A total of 724 specimens were collected and classified into 5 families, 14 genera, and 18 species. The overall results revealed that most fish fauna of river Panjkora contains 8 species of family Cyprinidae (56.49%) followed by 4 species of Nemacheilidae (24.44%), 2 species of Channidae (10.63%), and Sisoridae (7.04%), and 1 species of Mastacembelidae (1.38%), respectively. Among all kinds of fish species, Schizothorax plagiostomus (16.57%) was highly dominated and followed by Carassius auratus (11.87%) and Racoma labiata (9.66%) and were reported as highly abundant, especially during April, May, and June. The least abundant species were Glyptothorax punjabensis, Glyptothorax sufii, and Mastacembelus armatus, that constituting 2.48%, 2.20%, and 1.38% of the total fish samples. The Overall Simpson's diversity (1-D= 0.919) and Simpson's Reciprocal index values (1/D= 12.3876), and Shannon's index (H= 2.68) were indicating that river Panjkora contains a quite rich and diverse group of fish species. The highest microplastics observed in site 7 compared to other study area. Conservation steps should be taken as a top priority to protect and conserve the marine environment and natural heritage from further loss, extinction and stop or minimize losses incurred through irresponsible fishery practices.

Distribution and diversity of aquatic insects in different water bodies of Qatar.

Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalef's diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar.

Plant community differentiation of desertification region in northwest Liaoning Province, China

Understanding plant communities in desertification area is the scientific basis of evaluating the local eco-environmental quality and carrying out desertification control. According to longitude, we divided the desertification area in northwest Liaoning Province into three regions: the eastern region (122°50'37″ -123°49'40″ E), the middle region (121°16'41″-122°35'00″ E), and the western region (119°20'03″ -120°02'41″ E), and investigated the plant communities in each region. The results showed that the proportion of forest and canopy density of tree layer increased from the west to the east. Ass. Pinus sylvestris var. mongolica and Ass. Populus sp. in the eastern, Ass. Pinus tabuliformis and Ass. Populus sp. in the middle, as well as Ass. P. tabuliformis and Ass. Prunus sibirica in the western were dominant communities, respectively. The proportion of brush community in the eastern, middle and western was 0, 22.2%, and 28.0%, respectively. Grasslands formed mainly by human disturbance in the eas-tern and middle regions. The total species numbers were 110 in the middle, 88 in the western and 75 in the eastern, respectively. Therophytes were dominant in the eastern and middle with proportions of 68.2% and 66.7%, respectively. Hemicryptophytes were the dominant type (36.3%) in the western region. The proportion of microphanerophyt, nanophanerophyte, chamaephyte, and geophyte increased from the eastern to the western. The species number, Shannon index, and Simpson diversity index of the middle were the highest among the three regions. Pielou evenness index increased gradually from the eastern to the western. Community similarity between the eastern and the western was the lowest, as shown by the β-biodiversity, and the similarity between the middle and the western was the highest. The community type, species number, characteristics of species composition and species biodiversity of the middle region had the characteristics of ecological transition zone. In general, vegetation status in the desertification area of northwest Liaoning Province was in good condition. There were still some problems including the monotonous vertical structure of forest and tree species as well as the serious human interference.

Dynamics of collection accumulation: estimation of research efforts on the example of the mammal fauna of Cherkasy oblast, Ukraine

The article deals with the dynamics of the amassment of natural history collections on the example of one of the regions of Ukraine, the fauna of which is under constant attention of researchers. This region is the Middle Dnipro Region, namely Cherkasy Oblast in general and Kaniv Nature Reserve in particular, which are the sites of long-term monitoring studies of fauna and bases for conducting field research and field practices of students. The dynamics of collections development is considered on the example of the collections of the National Museum of Natural History of the National Academy of Sciences of Ukraine. The article shows the continuity of specimen income to the collections and, at the same time, significant changes in the dynamics of such income. Several indicators that can reflect the dynamics of research efforts are proposed. The decades (1900–1919, etc.) are chosen as time periods, and the variables are the total number of specimens per decade and the total number of families they represent. These indicators can be used to evaluate three dependent notions: in terms of fieldwork, the completeness of the captures (records); in terms of research history, the intensity of research; and in terms of museology, the abundance of collections. Among the indicators tested are the geometric mean (SQRT (Nfam × Nsp)), the quadratic mean (SQRT [(Nfam2 + Nsp2) / 2]) and the Simpson diversity index (1 / ∑ (pi)2). The first two indicators are highly dependent on sample sizes and therefore vary widely; and for this reason, the author recommends using with Simpson’s diversity index. It can be used to estimate the distribution of not only the number of specimens by family for each decade (essentially a comparison of family abundance), but also any other distributions, replacing families with genera or orders and changing the analysis periods depending on the amount of available data. The term ‘research effort’ can be used as a synonym for ‘collecting effort’, which can be found in the publications of English-speaking colleagues. The algorithm for assessing ‘research effort’ is an important tool in analysing the history of collections, levels of research on regions, and the history of research.

Compositional and Structural Diversity of Woody Stands in the Community Forests of Rogho and Boala in Central-West Burkina Faso

The biodiversity of community forests is poorly studied in Burkina Faso. This results in a lack of understanding of their ecological importance, which is characterized by neglect in their management. The main objective of this study is to characterize the flora and woody vegetation of the community forests of Rogho and Boala to demonstrate their importance. For this purpose, a forest inventory was conducted using stratified random sampling methods. Shannon, Simpson, Margalef, and Pielou diversity indices reveal significant biodiversity of the flora in both forests, with a better distribution of individuals within the species that make them up. The horizontal structure of the two woody populations is characterized by a predominance of individuals with small diameters (DBH € [5cm-25cm[) on either side, with respective regeneration rates of 58.36% and 22.46% for Rogho and Boala. Regarding the ecological importance of species, Lannea microcarpa has the highest Importance Value Index (IVI = 99.06) for the Rogho site, and Vitellaria paradoxa for the Boala site (IVI = 136.58). Phanerophytes dominate the flora of both forests with a strong presence of mesophanerophytes. The average density of woody plants is evaluated at 330.34 trees/ha and 742.01 trees/ha respectively in Rogho and Boala, with respective average land areas of 14.8 m2/ha and 119.78 m2/ha. This study highlights the strong ecological potential of the forests studied. Communal and regional authorities must develop strategies for the sustainable management of these forest areas.

Assessment of light-emitting diodes for sampling phlebotomines (Diptera: Psychodidae) from an urban park of the Brazilian Amazon.

The present study aimed to assess different light sources for sampling phlebotomines (Diptera: Psychodidae) from Bosque Rodrigues Alves, a forested park surrounded by the urban area of Belém in the Brazilian Amazon. Centers for Disease Control traps, baited with blue, green, and warm white light-emitting diodes (LEDs), as test group, and incandescent light, as control group, were used. The electromagnetic spectra and luminous intensities of the light sources were characterized. Fractional vegetation cover at each sampling site was also estimated. Abundance, richness, rarefaction curves, Shannon and Simpson diversity indices, phlebotomines/trap/hour, and phlebotomines/trap/night were estimated and compared. The light sources of the test group presented greater luminous intensity than the control, but were similar to each other. There were no differences in vegetation cover at each site. A total of 1,346 phlebotomines comprising 11 species were sampled. The most abundant species were as follows: Nyssomyia antunesi (Coutinho, 1939), Trichophoromyia ubiquitalis (Mangabeira, 1942), Bichromomyia flaviscutellata (Mangabeira, 1942), and Th. brachipyga (Mangabeira, 1942). Light traps with LEDs had richness, abundance, and Shannon diversity indices similar to those obtained with incandescent light. The warm white LED had a higher Simpson's index than the other light sources. Phlebotomine responses to incandescent light were similar to those to LEDs in most analyses, confirming the applicability of these light sources as alternative devices for entomological surveillance. Low consumption ensures greater autonomy of the traps, providing better operability during fieldwork.

Nematodes as biological indicators of urban heat island effects in the Chongqing area urban green spaces

The urban heat island effect (UHIE) is defined as the tendency of urban regions to have higher temperatures than suburbs in their immediate vicinity. A better understanding of UHIE and its biological indicators facilitates the prediction of ecological changes, which is particularly important due to ongoing global warming. To determine whether soil nematodes may serve as biological indicators of UHIE, we compared soil nematode communities under three urban green spaces, namely, urban cold islands (CI), urban heat island transition regions (HIT), and urban heat islands (HI). Distinct soil nematodes characteristics were found in the 3 urban green spaces. In addition, seasonal variations in community composition were identified. Among the 30 nematode genera identified, Eucephalobus was the most dominant in CI and HIT, while Monhystera was the most dominant in HI. The mean nematode abundance significantly differed (p ≤ 0.01) between CI (322 ± 24 individuals/100 g dry soil), HIT (112 ± 9 individuals/100 g dry soil), and HI (107 ± 10 individuals/100 g dry soil). We found that UHIE had detrimental effects on the nematode community structure (i.e., abundance and Margalef, Shannon-Wiener, and Simpson diversity indices) and ecological function [Free-living Nematode Maturity Index (MI), Nematode Channel Ratio (NCR), Enrichment Index (EI), and Structure Index (SI)]. These detrimental effects were reflected in nematode community structure indices, which were all highest in CI and lowest in HI, as well as in MI and SI, which were lower in HI than in CI. Furthermore, nematodes found in HI were shorter (L = 502.15 μm), thinner (W = 38.42 μm), and exhibiting higher length-to-width ratios (L:W) (15.83) compared to nematodes found in CI (L = 986.13 μm, W = 83.58 μm, L:W: 12.24) and HIT (L = 786.80 μm, W = 58.88 μm, L:W: 14.82). Nematode biomass spectra (NBS) shifted towards smaller biomass classes in HI compared to CI, while nematodes of the HIT showed intermediary spectra, further confirming the detrimental effects of UHIE on the soil nematode community. Regarding the physicochemical properties of the 3 green spaces, CI was found to have the highest soil pH, moisture, organic carbon content, total nitrogen content, and available potassium content, while HI had the lowest. Soil physicochemical characteristics were inversely correlated with soil temperature, except for available soil phosphorus, which was positively corrected with temperature. We also found that soil characteristics were significantly correlated with nematode community structure and ecological function, suggesting that the effects of UHIE on soil nematodes could have been indirectly affected by changes in soil physicochemical characteristics.

New record and dietary ecology of an endangered amphibian species, Micryletta nigromaculata Poyarkov, Nguyen, Duong, Gorin & Yang, 2018, from Vietnam

The Black-spotted Paddy Frog (Micryletta nigromaculata) was recently discovered from northern Vietnam. Due to its restricted distribution in limestone karst forests and habitat degradation, the endemic species has been listed as “Endangered” in the IUCN Red List. However, knowledge about the natural history of this species is scarce, including data on its dietary ecology. Recent field surveys revealed new populations of M. nigromaculata occurring in Son La Province, northwestern Vietnam based on morphological analysis. Using the stomach-flushing method, we analyzed stomach contents of 45 individuals (21 males and 24 females) from a total of 52 captured frogs because stomachs of six males and one female (13.5%) were empty. The food spectrum of M. nigromaculata comprises 12 types with a total of 691 prey items (687 invertebrate items and four unidentified items), belonging to six insect orders, larvae and Araneae. Similar to other species of the family Microhylidae, M. nigromaculata is also identified as an ant (Formicidae) – termite (Rhinotermitidae) eating specialist with distinctly higher percentages of occurrence frequency (F = 65 %), number of prey items (N = 80 %), and importance (Ix = 75 %) than those of remaining types. The Simpson diversity index of 0.939 shows a high abundance of food prey in the wild, and the Evenness index of 0.536 suggests biased consumption of feeding selection for M. nigromaculata.

Influences of phosphorus-modified biochar on bacterial community and diversity in rhizosphere soil.

Root-associated bacteria play a vital role in the soil ecosystem and plant productivity. Previous studies have reported the decline of bacterial community and rhizosphere soil quality in the cultivation of some medicinal plants (i.e., Pseudostellaria heterophylla). Phosphorus (P)-modified biochar has the potential to improve soil health and quality. However, its influence on the bacterial community and diversity in the rhizosphere of medicinal plants is not well understood. Therefore, this study aims to investigate the effects of P-modified biochar on the bacterial community and diversity in the rhizosphere of P. heterophylla. Soil samples were collected from the rhizosphere of 4-month P. heterophylla under control (no biochar), 3% unmodified and 3% P-modified biochar treatments, respectively. Compared with control and unmodified biochar treatment, P-modified biochar significantly increased the relative abundance of plant-beneficial bacteria (P < 0.05), particularly Firmicutes, Nitrospirae and Acidobacteria. The relative abundance of Bacillus, belonging to Firmicutes, was dramatically raised from 0.032% in control group to 1.723% in P-modified biochar-treated group (P < 0.05). These results indicate the potential enhancement of soil quality for the growth of medicinal plants. The application of biochar significantly increased bacterial richness and bacterial diversity (P < 0.05). P modification of biochar did not have significant effects on soil bacterial richness (P > 0.05), while it reduced Shannon and increased Simpson diversity index of soil bacterial communities significantly (P < 0.05). It indicates a decrease in bacterial diversity. This research provides a new perspective for understanding the role of P-modified biochar in the rhizosphere ecosystem.

Gut Microbiota Richness and Diversity Track With T Cell Aging in Healthy Adults.

This study examined how gut microbiota diversity and richness relate to T cell aging among 96 healthy adults of all ages. It also explored whether these links differed throughout the lifespan. Peripheral blood was obtained from 96 study participants (N = 96, aged 21-72) to assess mRNA markers of T cell aging (p16ink4a, p14ARF, B3gat1, Klrg1) and DNA methylation. T cell aging mRNA markers were combined into an aging index, and the Horvath epigenetic clock algorithm was used to calculate epigenetic age based on DNA methylation status of over 500 loci. Participants also collected a stool sample from which the V4 region of the 16S rRNA gene was sequenced to derive the Shannon and Simpson diversity indices, and the total count of observed operational taxonomic units (richness). Models controlled for BMI, comorbidities, sex, dietary quality, smoking status, physical activity, and sleep quality. Lower microbiota richness was associated with higher T cell age based on mRNA markers, but when probing the region of significance, this relationship was only significant among adults 45 years and older (p = .03). Lower Shannon diversity (p = .05) and richness (p = .07) marginally correlated with higher epigenetic age (ie, greater T cell DNA methylation). Gut microbiota complexity may correspond with the rate of T cell aging, especially in mid-to-late life. These results suggest an interplay between the gut microbiome and immunological aging that warrants further experimental work.

Differences in the gut microbiota between Gurkhas and soldiers of British origin.

Previous work indicated that the incidence of travellers' diarrhoea (TD) is higher in soldiers of British origin, when compared to soldiers of Nepalese descent (Gurkhas). We hypothesise that the composition of the gut microbiota may be a contributing factor in the risk of developing TD in soldiers of British origin. This study aimed to characterise the gut microbial composition of Gurkha and non-Gurkha soldiers of the British Army. Recruitment of 38 soldiers (n = 22 Gurkhas, n = 16 non-Gurkhas) and subsequent stool collection, enabled shotgun metagenomic sequencing-based analysis of the gut microbiota. The microbiota of Gurkhas had significantly (P < 0.05) lower diversity, for both Shannon and Simpson diversity indices, using species level markers than the gut microbiota of non-Gurkha soldiers. Non-metric Multidimensional Scaling (NMDS) of the Bray-Curtis distance matrix revealed a significant difference in the composition of the gut microbiota between Gurkhas and non-Gurkha soldiers, at both the species level (P = 0.0178) and the genus level (P = 0.0483). We found three genera and eight species that were significantly enriched in the non-Gurkha group and one genus (Haemophilus) and one species (Haemophilus parainfluenzae) which were enriched in the Gurkha group. The difference in the microbiota composition between Gurkha soldiers and soldiers of British origin may contribute to higher colonization resistance against diarrhoeal pathogens in the former group. Our findings may enable further studies into interventions that modulate the gut microbiota of soldiers to prevent TD during deployment.

Impact of water-based recreation on aquatic and riparian biodiversity of small lakes

Lakes offer important recreational sites for people; however, water-based recreation may interfere with conservation objectives. In this study, we examined the impact of recreational use of small stagnant water bodies (<22 ha) on several aquatic and riparian biodiversity indicators (species richness, Simpson diversity-index, and number of endangered species) across multiple taxa (waterfowl, songbirds, damselflies, dragonflies, amphibians, fishes, submerged macrophytes, riparian herbs and trees). Samples were generated from 39 gravel pit lakes in Lower Saxony, Germany. Recreational use intensity was quantified using a stratified roving creel survey design involving citizen scientists. Recreational use had little correlation with the different biodiversity indicators that we examined. Most of the variance in biodiversity was explained by non-recreation related environmental and land use variables. Yet, a consistent negative relationship between recreation and biodiversity was found for dog walking, which was negatively associated with the species richness of songbirds, fish, and riparian herbs. Other recreational effects were positive, e.g., increased human use intensity correlated positively with the species richness of fishes and riparian herbs. Moreover, lakes used exclusively by anglers hosted a larger fish species richness at the expense of amphibian richness, likely due to predation impacts by fish. The abundance of dogs was found to be more influential in terms of recreation-related impacts than human density per se, possibly because wildlife perceives dogs as a stronger threat stimulus than human presence. Experimental work is needed to substantiate the correlative evidence presented here.

Identification of Floral Resources Used by the Stingless Bee Melipona beecheii for Honey Production in Different Regions of the State of Campeche, Mexico

The stingless bee Melipona beecheii is experiencing colony decline due to floral resource scarcity caused by deforestation. A study was conducted to identify the floral resources used by M. beecheii using honey samples collected in four regions of the state of Campeche, Mexico. A melissopalynological analysis of sixteen collected honey samples identified 69 plant species from 24 families, and established that Fabaceae was the main plant family visited. Based on botanical origin, seven samples were classified as monofloral and nine as multifloral. The predominant species were Bursera simaruba, Lonchocarpus longistylus, Piscidia piscipula, Senna pallida and Senna racemosa. Shannon diversity index values (2.06–2.55) indicated moderate diversity in floral resources and Simpson diversity index values (0.82–0.89) indicated a moderate dominance of plant species in the studied regions. The results suggest M. beecheii is polylectic with some degree of specialization. The plant species identified as predominant in the studied honey samples are candidates for use in strategies intended to conserve the food resources used by M. beecheii on the Yucatan Peninsula.

Traditional homegardens change to perennial monocropping of khat (Catha edulis) reduced woody species and enset conservation and climate change mitigation potentials of the Wondo Genet landscape of southern Ethiopia

Smallholder farmers in the Wondo Genet were forced to switch from long-standing, diverse traditional home gardens to monoculture khat production due to increasing population pressure-induced farmland constraints. The composition of woody species and the biomass carbon stock are thought to drop as homegardens transition from polyculture to monoculture; however there is little quantitative evidence to support this claim. This study was started to assess the effects on woody species, enset, and biomass carbon of converting traditional homegardens to a fast spreading perennial monocropping of khat (Catha edulis Forskal). In 10 m × 10 m (100m2) plots from 43 farms with neighboring land use patterns for each homegarden and khat, woody species and enset were inventoried, the total number of tree, shrub, and enset species counted, as well as the height and diameter of each species measured. To determine the biomass carbon stock of each land use type, both general and species-specific allometric equations are used. Simpson's diversity index, Shannon-Wiener, and Shannon equitability were used to evaluate the diversity of enset and woody species. There were 27 different types of woody species identified, with trees making up 67 % of the total and shrubs accounting for 33 %. Shannon, Simpson, and the richness of woody species all decreased by 46 %, 51 %, and 38 %, respectively, in comparison to residential gardens. For homegardens and khat, respectively, the mean Evenness values were 0.876 and 0.539. In homegardens, Coffea arabica was the most valuable woody species, followed by Cordia africana Lam, Persea americana, Eucalyptus camaldulensis, and Grevillea Robusta. In contrast, Catha edulis was the most valuable woody species in the Khat land use type, followed by Coffea arabica, Croton macrostachyus Del, and Cordia africana. In comparison to homegardens, the above-ground, below-ground, and total biomass carbon reported in khat land use types were reduced by 18 %, 63 %, and 42 %, respectively. Grevillea and Eucalyptus species made up 51 % of the total biomass carbon stock in the homegardens, which suggests that khat and quickly expanding fast-growing plants have displaced native woody species.Understanding the long-term effects of agro-biodiversity loss requires greater research on the implications of the decline in woody species diversity and biomass carbon stock on soil fertility and sustainable farming. This is due to the numerous functions that woody species and enset play.

Impacts of the Koka hydropower dam on macroinvertebrate assemblages in the Awash River Basin in Ethiopia

The Koka hydropower dam is one of the oldest large dams in Ethiopia. Damming is one of the anthropogenic activities impacting the distribution of aquatic life forms. However, to date, little attention has been focused on the dam’s impacts on the river macroinvertebrate assemblages in Ethiopia. The objective of this study was, therefore, to assess the impacts of the Koka hydropower dam on macroinvertebrate assemblages in the Awash River basin in Ethiopia. In the three river reaches on the Awash River (upstream near the source of the river, midstream above the dam, and downstream below the dam), a total of 15 sites were selected for sampling. The statistical analysis tested the null hypothesis that there are no differences in macroinvertebrate assemblage patterns or a range of univariate metrics between the three river reaches. Additional analyses involved the identification of taxa responsible for significant differences in macroinvertebrate structure (e.g., percentage similarity) and an exploration of the variables that structure macroinvertebrates (e.g., canonical correspondence analysis). In the upstream, midstream, and downstream reaches of the Awash River, we recorded a total of 73 taxa belonging to 43 families and 12 orders. Trichoptera was the dominant order in the upstream river reach, whereas Diptera dominated the midstream and downstream river reaches. The diversity of macroinvertebrates decreased from upstream to midstream and downstream. The three river reaches differed significantly in Shannon and Simpson diversity indices, % EPT, EPT taxa abundance, total taxa richness, evenness index, % collectors, and % scrapers. In this study, we observed that macroinvertebrate assemblage differences and spatial patterns were significantly associated with values of river flow changes (velocity), phosphate concentration, and substrate index. The findings of this study have broad implications for the assessment of the impacts of dam construction on the rivers of the studied region in the future.

Effects of repeated afidopyropen treatment on the structure and function of the soil microbial community

Chemical insecticides are the most effective pest control agents. Afidopyropen is a novel insecticide used against sap-sucking insects, such as aphids. However, the effects of repeated afidopyropen application on the structure and function of soil microorganisms remain unknown. In this study, the changes in the enzyme activities, community structure and function, and relative abundance of antibiotic resistance ontology (ARO) of soil microorganisms were investigated during three repeated afidopyropen applications under laboratory conditions at the maximum recommended dosage (M1) and 10 times the M1 (M10). The neutral phosphatase (NPA) and catalase (CAT) activities in the soil were significantly suppressed after afidopyropen treatment. The Simpson diversity index (1/D) and Shannon–Wiener diversity index (H) also decreased in both the M1 and M10 afidopyropen-treated soils, indicating a remarkable decrease in soil microorganism diversity. The average well color development (AWCD) first increased and subsequently recovered to normal levels after the third application of the insecticide, suggesting that afidopyropen application could increase the metabolic activity of soil microorganisms. Metagenomic analysis showed that repeated afidopyropen application in both the M1 and M10 treatment groups altered the community structure of soil microorganisms, albeit in different ways. Furthermore, repeated afidopyropen application significantly increased the relative ARO abundance, especially in the M10 treatment, with the most dominant AROs being adeF, baeS, and IND-6. These findings reveal the effects of excessive afidopyropen application on soil microorganisms and lay an important foundation for the comprehensive evaluation of the impact of this insecticide on the environment.