Shannon-Wiener Diversity Index Research Articles

Ground ants as indicators of biodiversity in cashew agroecosystems in Tanzania

BackgroundAnts are a diverse and ecologically important group of insects that play vital roles in terrestrial ecosystems globally. In agricultural settings, they act as effective biocontrol agents against insect pests. Ants also serve as bioindicators of environmental health, reflecting changes in habitat and pollution. However, research on their diversity and population dynamics in cashew agroecosystems remains limited.ResultsThe sampling was conducted using a pitfall trap that targeted three sampling zones viz., under African weaver ants colonised (AWAC) cashew trees, AWA-uncolonised (AWAUC) ones, and buffer zones (BZ). A total of 14,004 ants from six subfamilies, 18 genera, and 32 species were sampled, with 7,686 sampled during season one and 630 sampled during season two. The study found significant differences in ant populations across sampled zones, which were significantly different in season one (F(2.107) = 5.4; P = 0.01) and season two (F(2.107) = 3.32; P = 0.04). However, more ants were sampled under AWAUC cashew trees compared to AWAC cashew trees and the BZ (F(2.74) = 4.46; P = 0.02) at Nyamato during season one. The Shannon–Wiener diversity index yielded comparable results to Margalef’s species richness index for all three zones, which differed significantly in both seasons at Nyamato and season one at Chambezi. A SIMPER analysis showed an overall dissimilarity of 94.5% at Soga due to the presence of invasive species (Pheidole megacephala and Anoplolepis custodiens) and AWA, which was consistently observed across all the experimental sites.ConclusionThe variety and number of ant species in cashew agroecosystems are influenced by several factors, including the presence of dominant ant species and weeding practices. Promoting biodiversity in agricultural ecosystems is crucial for supporting beneficial insect populations and mitigating the risks posed by invasive ant species. Currently, there is no effective bait available for controlling these invasive ant species, indicating a need for further research to develop such bait. This would facilitate the foraging activities of other ant species, including beneficial ones.

Railway Infrastructure as a Substitute Habitat for Valuable Medicinal Plant Species Using the Example of Bearberry Arctostaphylos uva-ursi

The secondary, substitute habitats are becoming more important for the survival of many valuable plant species, including medicinal plants—for example, bearberry Arctostaphylos uva-ursi. The aim of the conducted research is to compare the ability of A. uva-ursi to accumulate heavy metals in leaves from railways (anthropogenic substitute habitat) and the natural habitats (pine forests). We measured the concentration of five heavy metals (Cd, Hg, Ni, Pb, and Zn) in plant material and in the soil. The bioaccumulation factor was also calculated. Moreover, we measured biotic factors including A. uva-ursi height and abundance, along with the plant diversity indices, in the investigated plots. The presented results reveal that (1) none of the parameters concerning the content of the selected heavy metals described in the currently applicable legal acts were exceeded, (2) A. uva-ursi does not show the potential for heavy metal accumulation, except for zinc and partially mercury, (3) its individuals in the natural habitats are lower, (4) the abundance (percentage cover) of A. uva-ursi is the lowest in the natural habitat, and (5) the value of the Shannon–Wiener diversity index is the highest in the vegetation patches with A. uva-ursi developed in natural habitats.

The Effect of Sampling Schedule on Assessment of Dietary Measures: Evidence From Blue Monkeys (Cercopithecus mitis stuhlmanni).

Accurately assessing primate diets is important in studies of behavioral ecology and evolution. While previous research has compared sampling methods (scan, focal), we examined how sampling schedule influences accuracy of dietary measures. We define sampling schedule as the combined distribution (random vs. consecutive) and frequency of sampling days within a given month. Under field conditions, time may be required to locate a study group, and we therefore also subtracted 1, 2, or 3 h from the beginning of all non-consecutive days in each sampling schedule to mimic observation time lost to search. From a dense (near daily) 5-year record of feeding behavior derived from focal animal follows of adult females in five wild blue monkey (Cercopithecus mitis) groups, we created data subsets matching various sampling schedules, and compared monthly dietary measures calculated from each subset to those based on the full data set. These measures included (1) the proportion of observation time feeding on fruit, (2) diet composition (three top-ranked food items), (3) species richness of plant diet, (4) Shannon-Wiener diversity index based on plant species, and (5) Holmes-Pitelka index expressing dietary overlap with the previous month. We used generalized linear mixed models to assess how frequency and sampling type (a combination of distribution and hours lost) relate to a subset's deviation from the full data set, where a smaller deviation (or higher chance of matching, for diet composition) implies greater accuracy. For all dietary measures, increasing observation frequency increased accuracy. The response to distribution varied among measures, but sampling types generally differed more at lower frequencies. Deviation varied widely within and between dietary measures, and some sampling schedules resulted in values with large percentage differences from the "full" data. Accordingly, when designing and comparing studies, researchers should consider how sampling schedules may influence the accuracy of the dietary measures of interest.

Multivariate Environmental Factors and Seasonal Spatial Dynamics Affecting the Phytoplankton Community in Yazhou Bay, South China Sea

This study investigated phytoplankton and water environmental factors in Yazhou Bay, South China Sea, during the winter, spring, and summer of 2023. It examined phytoplankton community structure, subgroup heterogeneity, and key environmental drivers. Phytoplankton abundance ranged from 0.08 to 14.30 × 10⁴ cells·L−1, with high concentrations in estuary and nearshore zones. In summer, currents carry phytoplankton offshore, with stratification leading to high sedimentation in southern offshore waters. RDA results indicated that in winter and spring, inorganic nitrogen mainly influences phytoplankton distribution, while silicate is the primary factor in summer. Although seasonal differences in total phytoplankton abundance are minimal, significant horizontal and vertical distribution variations exist. Diverse preferences of different phytoplankton species for temperature, salinity, nitrogen, and phosphorus result in high species diversity. The Shannon–Wiener diversity index (H′) averages 3.96 ± 0.09, and the Pielou evenness index (J) averages 0.82 ± 0.01. Dominant species include Pseudo-nitzschia pungens, Skeletonema costatum, and Rhizosolenia sinica. Influenced by external oceanic water masses, estuary input, and islands, phytoplankton subgroups show regional and seasonal variations. Despite recorded harmful algal blooms (HABs) in adjacent waters, Yazhou Bay’s high biodiversity and low cell density suggest a low HAB risk, though future risks due to climate change and human activities remain.

Genetic Diversity of Native Provenance and Plantation Populations of Pinus sylvestris var. mongolica Based on SSR Markers and Morphological Traits.

Pinus sylvestris var. mongolica plays a crucial role in the ecological restoration and industrial raw material production of arid and semiarid regions in northern China. The widespread degradation of its near-mature plantation (over 30 years) is a significant concern, having been a topic of interest in recent decades. In this study, the genetic diversity and population genetic structure were assessed using 12 simple sequence repeat (SSR) markers within 11 native provenance populations and eight plantation populations. Additionally, variations in eight morphological traits of their offspring were evaluated at three sites in northern China. The results revealed high genetic diversity and weak genetic differentiation among the native provenance populations. The mean number of alleles (N a), allelic richness (A r), expected heterozygosity (H e), and Shannon-Wiener diversity index (I) were 5.492, 4.679, 0.550, and 1.120, respectively, and the genetic differentiation coefficient (F ST) was 0.022. Significant population effects of tree height and height to live crown base (HCB), as well as interactions of population with site and block within site, were observed in tree height, HCB, stem diameter at breast height (DBH), stem volume (VOL), crown shape (CS), and disease grade (DG). The genetic diversity parameters based on SSR markers and breeding values of tree height, DBH, HCB, VOL, and stem form (SF) of plantation populations were found to be lower than those of native provenance populations. Significant positive correlations were identified between the mean effective number of alleles per locus (N e) and VOL as well as H e and crown width (CW). Furthermore, the maximum temperature of the warmest month (BIO5) and the silt content (T_SILT) were identified as significant factors influencing genetic diversity parameters and morphological variation, respectively. The findings provide scientific support for the reduction of plantation degradation, the effective restoration, and the sustainable management of forests for this species.

Exploring the diversity of bryophytes through DNA barcoding in montane forests of the Private Conservation Area San Pablo Communal-Gocta Waterfall, Peru

Bryophytes (liverworts, mosses, and hornworts) play crucial ecological roles in the ecosystem. However, for the Private Conservation Area (PCA) San Pablo Communal-Gocta Waterfall, there are no records of the diversity of this group of plants, despite being in the territory of the Peruvian Yungas, which is considered to be a biodiversity hotspot. In this study, the diversity of bryophytes within the PCA was characterized using the rbcL. In addition, Shannon-Wiener and Simpson diversity indices were used to evaluate the species richness within the three life zones of the PCA [Tropical Premontane Dry Forest (TP—df), Tropical Low Montane Dry Forest (TLM—df) and Tropical Low Montane Humid Forest (TLM—hf)]. A total of 139 individuals were collected and 83 species were identified; these individuals were located in 49 genera and 33 families. The predominant species were Boulaya sp., Dicranolejeunea axillaris and Frullania cuencensis. The diversity indices showed a high diversity of bryophytes in the PCA, with values between 2.90 and 3.85 for the Shannon index and 0.93 and 0.97 for the Simpson index. This study provides information based on molecular tools on the bryophyte flora and contributes to the conservation of biodiversity in the San Pablo Communal PCA, Gocta Waterfall.

Keanekaragaman Jenis Anggang-anggang (Gerris marginatus) di Aliran Sungai Taman Wisata Alam Kerandangan Kabupaten Lombok Barat

Flywheels are a type of insect belonging to the Family Gerridae. Flywheels are insects that are usually found in calm waters such as ponds, rivers and lakes. The aim of this research was to determine the index of diversity of flywheels species in the river flow of Kerandangan Nature Tourism Park, West Lombok Regency. The type of research used is exploratory descriptive research. The data analysis technique in this research uses the Shannon-Wiener diversity index. The results of the research show that the species diversity index value of flywheels (Gerris marginatus) in the Kerandangan Nature Tourism Park is in the low category, with a total of 0.0693 in post 1, post 2 totaling 0.3518, and post 3 totaling 0.3463.

Biochar Organic Fertilizer Combined with Indigenous Microorganisms Enhances the Growth of Landscape Grass Cultivated in a Substrate Mixed with Iron Tailings and Mining Topsoil.

Iron tailings from the mining process occupy vast land areas and pose a significant ecological risk. In order to reuse iron tailings resources and carry out in situ ecological restoration of a mine, in this study, a medium of mixed iron tailings and mining topsoil (m:m = 3:1) was used to plant landscape grasses, including Lolium perenne L. (L. perenne), Pennisetum alopecuroides (L.) Spreng. (P. alopecuroides), Melilotus officinalis (L.) Lam. (M. officinalis), and Medicago sativa L. (M. sativa). Biochar and chicken manure were used as biochar organic fertilizers and indigenous microorganisms were isolated from the rhizosphere soil of tested grasses. They were applied to enhance landscape grass growth by regulating rhizosphere microbial communities and nutrient conditions. The results showed that the biochar organic fertilizers significantly promoted the growth of the four landscape grasses, notably P. alopecuroides, increasing plant height, root length, root weight, and leaf fresh weight by 169%, 60%, 211%, and 388%, respectively. Additionally, L. perenne exhibited the greatest height increase (10%) following the application of bacterial solutions. Moreover, indigenous bacterial solutions enhanced chlorophyll content and phenylalanine ammonia-lyase (PAL) activity, with P. alopecuroides showing the highest chlorophyll increase of 58% and M. sativa exhibiting a 30.58% rise in PAL activity. The biochar organic fertilizer also significantly elevated soluble protein content in P. alopecuroides and M. sativa by 195% and 152%, respectively. It also effectively enhanced peroxidase (POD) activity in Poaceae grasses by 120% to 160%. After adding indigenous microorganisms, the rhizosphere soil of the landscape grass showed the highest Shannon-Wiener diversity index, reaching 3.561. The rhizosphere soil of M. officinalis had the highest microbial richness, with a value of 39. Additionally, the addition of indigenous microorganisms increased the nitrogen, phosphorus, and potassium content of the four plants by 8-19%, 6-14%, and 8-18%, respectively. This study offers a new approach for managing mining waste and ecological restoration in mining areas.

Canting Expedition: Herpetofauna Diversity in the Mendolo Village, Lebakbarang, Pekalongan

Central Java is an area that has natural forests with quite high biodiversity potential, one of which is Mendolo Village, Lebakbarang, Pekalongan. The diversity of herpetofauna species is one of its potential biodiversity. Data collection on herpetofauna in Mendolo Village has not yet been carried out, even though this village is in direct contact with natural forests with great potential. The aim of this research is to reveal the diversity of herpetofauna types at this location. The method used is VES (Visual Encounter Survey). The data obtained was then analyzed using the Shannon-Wiener Diversity Index. There were 23 species of reptiles and 16 species of amphibians, with a Diversity Index value of 2.942 for reptile types and 2.28 for amphibians. The conclusion that can be drawn is that the diversity of herpetofauna species in Mendolo Village is in the quite high category.

Analisis Kelimpahan Fitoplankton dan Zooplankton di Sungai Batang Hari di Kabupaten Tebo

The aim of this research is to analyze the structure of plankton abundance and water quality in the Batang Hari River in Tebo Regency. The research method used was purposive sampling at 3 (three) points on the Batang Hari River during February - July 2024. The research results found 3 classes of Phytoplankton, namely: Bacillariophyceae, Chlorophyceae, and Cyanophyceae as well as 1 species of Zooplankton (Ciliata). This research also found the Shannon-Wiener diversity index (H') between 1.555 and 1.559; This shows the moderate stability of the plankton community and is supported by a water temperature of 28°C and adequate phosphate and nitrate content.

An Ecological Survey of Chiggers (Acariformes: Trombiculidae) Associated with Small Mammals in an Epidemic Focus of Scrub Typhus on the China-Myanmar Border in Southwest China.

Chiggers (chigger mites) are a group of tiny arthropods, and they are the exclusive vector of Orientia tsutsugamushi (Ot), the causative agent of scrub typhus (tsutsugamushi disease). Dehong Prefecture in Yunnan Province of southwest China is located on the China-Myanmar border and is an important focus of scrub typhus. Based on the field surveys in Dehong between 2008 and 2022, the present paper reports the infestation and ecological distribution of chiggers on the body surface of rodents and other sympatric small mammals (shrews, tree shrews, etc.) in the region for the first time. The constituent ratio (Cr), prevalence (PM), mean abundance (MA), and mean intensity (MI) were routinely calculated to reflect the infestation of small-mammal hosts with chiggers. Additionally, the species richness (S), Shannon-Wiener diversity index (H), Simpson dominance index (D), and Pielou's evenness index (E) were calculated to illustrate the chigger community structure. Preston's log-normal model was used to fit the theoretical curve of species abundance distribution, and the Chao 1 formula was used to roughly estimate the expected total species. The "corrplot" package in R software (Version 4.3.1) was used to analyze interspecific relationships, and the online drawing software was used to create a chord diagram to visualize the host-chigger associations. From 1760 small-mammal hosts, a total of 9309 chiggers were identified as belonging to 1 family, 16 genera, and 117 species, with high species diversity. The dominant chigger species were Leptotrombidium deliense, Walchia ewingi, and Gahrliepia longipedalis, with a total Cr = 47.65% (4436/9309), among which L. deliense is the most important vector of Ot in China. The overall infestation indexes (PM, MA, and MI) and community parameters (S, H, and E) of chiggers in the mountainous areas and outdoors were higher than those in the flatland areas and indoors, with an obvious environmental heterogeneity. Leptotrombidium deliense was the dominant species in the flatland and indoors, while G. longipedalis was the prevalent species in the mountainous and outdoor areas. The species abundance distribution of the chigger community conformed to log-normal distribution with the theoretical curve equation: S(R)'=28e-[0.23(R-0)]2, indicating the existence of many rare species and only a few dominant species in the community. The expected total number of chigger species was roughly estimated to be 147 species, 30 more than the 117 species actually collected, suggesting that some uncommon species may have been missed in the sampling survey. The host-parasite association analysis revealed that one host species can harbor different chigger species, and one chigger species can parasitize different host species with low host specificity. A positive or negative correlation existed among different chigger species, indicating a cooperative or competitive interspecific relationship. The species diversity of chiggers is high in Dehong on the China-Myanmar border, and a large host sample is recommended to find more uncommon species. There is an obvious environmental heterogeneity of the chigger community, with different species diversity and dominant species in different environments. The low host specificity of chiggers and the occurrence of a large number of L. deliense in Dehong, especially in flatland areas and indoors, would increase the risk of persistent transmission of scrub typhus in the region.

Biodiversity and Soil Reinforcement Effect of Vegetation Buffer Zones: A Case Study of the Tongnan Section of the Fujiang River Basin

The riparian vegetation buffer zone is an important component of riverbank ecosystems, playing a crucial role in soil consolidation and slope protection. In this study, the riparian vegetation buffer zones in the Tongnan section of the Fujiang River Basin were selected as the research object. Surveys and experiments were conducted to assess the species composition and the soil and water conservation effectiveness of the riparian vegetation buffer zone. There are a total of 35 species, mainly comprising angiosperms and ferns. The dominant species include Cynodon dactylon, Setaria viridis, Phragmites australis, Erigeron canadensis, and Melilotus officinalis. The Patrick richness index (R) and Shannon–Wiener diversity index (H) are more significantly influenced by the types of land use in the surrounding area, whereas the impact on the Simpson diversity index (D) and Pielou uniformity index (E) is comparatively less pronounced. When the root diameter is less than 0.2 mm, the tensile strength of Cynodon dactylon roots is the highest. For root diameters larger than 0.2 mm, Melilotus officinalis roots exhibit the highest tensile strength. The presence of plant root systems significantly reduces erosion, delaying the time to reach maximum erosion depth by 1–4 min, decreasing erosion depth by 9–38 mm, and reducing the total amount of erosion by 20.17–58.90%. The anti-scouribility effect of Cynodon dactylon is significantly better than that of Setaria viridis. The root system notably enhances soil shear strength, delaying the shear peak by 0.26–4.8 cm, increasing the shear peak by 4.76–11.37 kPa, and raising energy consumption by 23.76–46.11%. Phragmites australis has the best resistance to shear, followed by Erigeron canadensis, with Melilotus officinalis being the least resistant. Therefore, to balance the anti-scouribility effect and shear resistance of plant roots, it is recommended to use a combination of Cynodon dactylon and Phragmites australis for shallow-rooted and deep-rooted planting. This approach enhances the water and soil conservation capacity of riverbanks.

Comprehensive Evaluation and Selection of Cardamom (Elettaria cardamomum (L.) Maton) Germplasm Using Morphological Traits.

Cardamom (Elettaria cardamomum (L.) Maton) plays a crucial role in Guatemala's agriculture, supporting local families and covering 169,429.29 ha (making it the world's leading producer). Since its introduction to Guatemala in 1910, limited research has focused on unraveling the diversity and defining morphological traits critical for selecting excellent accessions. In this study, we examined 17 morphological traits across 288 accessions to identify key features associated with the germplasm. The comprehensive analysis employed principal component analysis, a morphological composite value (F-value), linear regression, and hierarchical clustering. The Shannon-Wiener diversity index ranged from 0.10 to 2.02, indicating the variation in diversity among traits. Principal component analysis and hierarchical clustering revealed six distinct germplasm groups. The comprehensive analysis facilitated the selection of 14 excellent accessions, and the regression equation incorporating criteria such as plant height, capsule color, panicle number per plant, panicle length, rhizome color, cluster number per panicle, cluster node length, and capsule number per cluster to identify cardamom germplasm. To develop a conservation strategy for the two putative foreign varieties ('Malabar' and 'Mysore'/'Vazhukka') introduced in Guatemala based on plant height, another 12 accessions were selected with a second comprehensive evaluation. This information offers insights into cardamom diversity for informed selection enhancing national utilization, productivity, and conservation.

Evaluation of the stock enhancement effect of Phascolosoma esculenta on macrobenthic communities using diversity and biotic indices in Yueqing Bay, East China Sea

Stock enhancement activities have many benefits but also negative impacts. The macrobenthic diversity index and the M-AMBI index were adopted to assess the effects of stock enhancement of Phascolosoma esculenta on macrobenthic communities and the local ecosystem in Yueqing Bay. The results revealed that the Shannon–Wiener diversity index (H’) and Margalef richness index (d) increased in October 2022 after stock enhancement, indicating a positive ecological restoration effect. The average M-AMBI in the intertidal zone of Yueqing Bay was 0.59, indicating good benthic ecological quality. Excluding seasonal factors, the M-AMBI in the intertidal zone increased after stock enhancement, indicating that stock enhancement by Phascolosoma esculenta had a certain positive effect on the intertidal ecological environment of Yueqing Bay. The increase in the M-AMBI occurred mainly in the low-tide zone, increased slightly in the mid-tide zone, and remained basically unchanged in the high-tide zone. On the one hand, Phascolosoma esculenta can accumulate heavy metals from the environment and release a large amount of organic matter throughout its lifecycle, promoting nutrient cycling, which plays a positive role in the environment. On the other hand, Phascolosoma esculenta is an economic species; however, the planting of mangroves in the low tide zone causes fishers to fish in the mid- and high-tide zones, so the changes in the M-AMBI values in each tidal zone are related mainly to Phascolosoma esculenta and anthropogenic disturbances.

Mapping forest tree species and its biodiversity using EnMAP hyperspectral data along with Sentinel-2 temporal data: An approach of tree species classification and diversity indices

Forests play a crucial role in maintaining ecological balance and biodiversity, making the accurate mapping of tree species and assessment of biodiversity indices essential for informed management decisions. This study introduces an innovative methodology that integrates EnMAP (Environmental Mapping and Analysis Program) hyperspectral data with Sentinel-2 multitemporal data to classify tree species in the biodiverse landscapes of Kampinos National Park and its surrounding regions in Poland.We extract essential vegetation indices such as NDVI, NDMI, SAVI, and EVI from Sentinel-2 data to assess forest health and dynamics. The Sentinel-2 data is upscaled from 10 m to 30 m to align with EnMAP’s spatial resolution, followed by precise co-registration of the images using QGIS. Utilizing a rich dataset from the National Forest Inventory, we extract spectral signatures of nine distinct tree species from both data sources. We employ five machine learning algorithms—Support Vector Machines (SVM), Random Forest (RF), CatBoost (CAT), Gradient Boosting Classifier (GBC), and XGBoost (XGB)—to enhance classification accuracy.Through iterative experimentation with data reduction techniques and algorithm tuning, we achieve optimal performance across needle-leaved and broad-leaved species. The resulting tree species maps are validated through quantitative accuracy assessments against mixed-species polygons from the National Forest Inventory and ground truthing in the Kampinos National Park. Achieving an overall accuracy of 85% to 93%, our study demonstrates the efficacy of this integrated approach in tree species mapping. Furthermore, the tree species maps serve as a foundation for deriving key biodiversity indices—species richness, Shannon-Wiener Diversity Index, Simpson’s Diversity Index, and a composite Biodiversity Index—providing insights into spatial biodiversity patterns and informing targeted conservation strategies. This study exemplifies the potential of combining advanced remote sensing techniques with field validation to enhance our understanding of forest ecosystems and guide sustainable management practices.

Diversity of Orchid in Abies nephrolepis Nature Reserve in Shanxi, China.

Abies nephrolepis Nature Reserve has complex habitats and rich species diversity but lacks systematic ecological surveys. We focused on Orchid in Abies nephrolepis Nature Reserve, investigated and analyzed Orchid diversity and changes in community structure according to the characteristics of the alpine valleys in the study area, in terms of altitude gradient and habitat type, using the sample line method and the quadrat method. The results showed that 11 genera and 13 species of Orchidaceae were found in the survey, among which the species richness of Malaxis monophyllos was the highest, Neottia puberula was the second highest, and the species richness of Tulotis ussuriensis was the lowest, and the species with relative plurality ≥ 10% were Malaxis monophyllos (51.69%), Neottia puberula (14.77%), and Cypripedium guttatum (11.15%). The results of diversity analysis showed that Orchidaceae species were rich and the diversity index were the highest in the middle altitude area of 1950-2250 m; the distribution of Orchidaceae in the low altitude area was obviously clustered, and the similarity with the high altitude area was low. With the increase in altitude, the number of species showed an increase and then a decrease, showing a single-peak state, which was in line with the theory of "Intermediate altitude expansion hypothesis". The species and number of Orchidaceae in different habitats of Abies nephrolepis Nature Reserve also varied considerably, with Shannon-Wiener diversity index being the highest in EV4 (Abies nephrolepis + Picea meyeri + Picea wilsonii + Larix gmelinii var. principis-rupprechtii-Lonicera hispida-Carex lanceolata community) and EV5, and the smallest in EV1 habitats, Pielow evenness index being the highest in EV5 habitats and the lowest in EV1 habitats, and Simpson's index being the highest in EV5 habitats and the lowest in EV1 habitats. This study provides a scientific basis for strengthening regional monitoring of species diversity and protecting biodiversity.

Impact of invasive alien plants on the resident floral diversity in Koshi Tappu Wildlife Reserve, Nepal.

Invasive alien plant species (IAPS) pose a serious threat to overall plant biodiversity across the globe. Nepal's national parks and protected areas are not devoid of the impact of IAPS. Unfortunately, there is a substantial gap in knowledge regarding the extent and impact of invasion in protected areas of Nepal. This study assessed the impact of invasive alien plant species on the resident plant species of the Koshi Tapu wildlife reserve. After a preliminary field observation, we selected five major IAPS in the area, Mesosphaerum suaveolens, Chromolaena odorata, Ipomoea carnea, Lantana camara, and Mikania micrantha for this study. Ten pairs of adjacent plots sized 4 m × 4 m were surveyed for each invasive species, comprising diverse vegetation types. Each pair consisted of one "invaded plot" where the invasive species was dominant with cover greater than 50%, and another "uninvaded plot" laid out in an adjacent area with similar site conditions but without the invasive species. We calculated the Sørensen Index of Similarity for each paired plot. Wilcoxon rank-sum test was employed to compare ecological parameters between invaded and uninvaded plots for various plant species. Similarly, the difference in impact between each of the five invasive species was assessed using the Kruskal-Wallis test. Species richness varied significantly between invaded and uninvaded plots for C. odorata and I. carnea. The most significant impact on species composition of invaded communities (39.6%) was observed for C. odorata. The cover of the other dominant species varied significantly between invaded and uninvaded plots for all five species studied. The Kruskal-Wallis test showed no significant difference in the impact caused by the five studied invasive species on Species richness, Shannon-Wiener diversity index, species evenness, and height of dominant species. However, a significant difference was observed between the impacts of five studied invasive species and the cover of other dominant species. The crown cover of dominant species decreased much more in the invaded plots of L. camara and M. micrantha than in other species. Specialized management efforts are required to control highly invasive species, such as C. odorata and I. carnea, alongside proactive measures to prevent further spread in ecologically sensitive areas.

Fish community structure in relation to habitat variables in a seasonally open floodplain wetland of the Yamuna River basin of India

The study was carried out in Alwara wetland, a seasonally open floodplain wetland connected to the Yamuna River in the Kaushambi District of Uttar Pradesh, - to estimate the fish community structure in relation to habitat variables across three seasons. Altogether, 62 fish species comprising 9 orders, 23 families and 50 genera were recorded, including 5 exotic species. As per IUCN categorisation, 5 species viz., Wallago attu, Ompok bimaculatus, O. pabda, Chitala chitala and Ailia coila are near threatened and Clarias magur is endangered. Cypriniformes (40.32%) were the most dominant order, followed by Siluriformes (22.58%), Perciformes (19.35%), Synbranchiformes (4.84%), Clupeiformes and Mugiliformes (3.23%), Tetraodontiformes and Beloniformes (1.61%). The Shannon-Wiener diversity index (H’) ranged from 3.421 (post-monsoon) to 3.877 (monsoon) with an uneven abundance of fishes as indicated by the evenness index (post-monsoon = 0.6951 to monsoon = 0.8186). Water quality parameters were significantly (p<0.05) different across the seasons except specific conductivity, silicate-Si, phosphate-P, and dissolved organic matter (DOM). Certain sediment quality parameters differed significantly (p<0.05) across the seasons. Canonical correspondence analysis (CCA) was used to study the association of 27 commercially important fish species with 6 important water quality parameters and provided the baseline information on fish community structure. We observed growth and recruitment overfishing, which may affect fish diversity and its sustainable utilisation to support fishers’ livelihoods. Keywords: Alwara wetland, Diversity indices, Fish community, Endangered, Overfishing

Ecological health assessment using zooplankton index of biotic integrity (Z-IBI) in urban rivers in Hainan Island, China.

The Changwang, Meishe, and Wuyuan are urban rivers in Haikou City, Hainan Island. They are vital water sources, serving various purposes, from farmland irrigation to domestic and industrial use. Unfortunately, anthropogenic activities have influenced these "rivers," negatively impacting water quality and ecological functions; however, there is limited research on their ecological status. Thus, this study assessed the zooplankton community structure and developed the zooplankton index of biotic integrity (Z-IBI) to evaluate the ecological status. Samples were collected and analyzed seasonally in 2019. Generally, 159 zooplankton species belonging to 85 genera, 55 families, and 3 phyla were identified, dominated by Rotifer and Protozoa, followed by Arthropoda (groups of Copepod and Cladocera). The zooplankton density varied from 0.00 to 126.04 ind L-1, with averages of 19.49 ind L-1, 31.40 ind L-1, and 20.38 ind L-1 in Changwang, Meishe, and Wuyuan, respectively. The zooplankton density varied seasonally as summer > spring > winter > autumn. Analysis of similarity (ANOSIM) indicated a significant seasonal difference (R = 0.070, p < 0.001) in zooplankton community but not spatially (R = 0.004, p = 0.413). Thus, SIMPER revealed that Brachionus forficula, Didinium nasutum, Keratella valga, Nauplius, and Polyarthra vulgaris contributed to the seasonal differences. The redundancy analysis (RDA) revealed environmental factors, including total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH3-N), chemical oxygen demand (CODMn), dissolved oxygen (DO), temperature, pH, Chl-a, and electrical conductivity (EC) influenced zooplankton species. The Z-IBI was established using Zooplankton abundance, Protozoa abundance, Copepod abundance, Cladoceran biomass %, and Shannon-Wiener diversity index. Based on Z-IBI evaluation, ecological status was "moderate" in Changwang and Wuyuan, while it was "low" in Meishe. Seasonally, the ecological status in autumn was better than in summer and spring. The Z-IBI showed that parameters, including pH, EC, CODMn, TN, TP, and Chl-a, decreased with improving water quality, while water transparency increased with improved water quality. Thus, the "rivers" ecological status could be adequately assessed using the Z-IBI to guide their water quality monitoring and management.

Rodents of Bahir Dar Blue Nile River Millennium Park, Ethiopia.

Rodents are mammals of the order Rodentia, which are found in all continents except Antarctica. They are the most diverse groups of mammals representing 41% of all mammals and they are known with 33 families, 481 genera, and about 2277 species. The present study was conducted from December 2018 to August 2019 both during the dry and wet seasons using Sherman traps and live traps. Four trap sites namely forest, bushland, grassland, and sugarcane plantation were selected for data collection. Shannon-Wiener diversity index (H') was used to compute rodent species diversity, Simpson's index (D) to assess the number and abundance of rodents in the different habitats, and one-way ANOVA and independent samples t-test were used for data analysis. A total of 163 individual rodents were captured in 1776 trap nights of which 125 individuals were captured using live traps in 1176 trap nights and 38 individuals using snap traps in 600 trap nights. Among the total individual rodents captured in the Bahir Dar Blue Nile River Millennium Park, 63.8% (n = 104) were males and 36.2% (n = 59) were females. Males outnumbered females in all the grids and the difference was significant (t = 31.5, df = 10, p < 0.05). The relative abundance of rodent species indicated that 42.4% (n = 53) were Arvicanthis niloticus, 26.4% (n = 33) Rattus rattus, 17.6% (n = 22) Mus musculus, 8% (n = 10) Mastomys natalensis, and 5.6% (n = 7) Arvicanthis abyssinicus. There are more individual specimens of A. niloticus than other species identified in the area (F = 698.22, df = 4, p < 0.05). Distribution of rodents varied among the different habitats. As a result, the bushland habitat showed more diversity of rodents (H = 0.98) and comprised relatively the highest (51.2%, n = 64) number of individuals captured, while the forest habitat supported the lowest number of rodents (4%, n = 5), and the difference showed a significant difference (F = 873.37, df = 3, p < 0.05). Population density with 95% confident interval estimated as 166 individuals/ha (95% CI:164.43-167.57). The present study provides basic information about population dynamics of rodents and contributes to design conservation strategies for rodents in particular and other biota of the area in general.