Dominance Index Research Articles

Diversity of Fish Species as Bioindicators of Water Quality in The Cikapundung River, Bandung City

Human activity along the river impacts the aquatic environment from biotic and abiotic factors. One indicator that can reflect the quality of the waters is fish diversity. Several studies have used fish diversity as a biological indicator to determine the quality of waters, such as lake and river waters. The purpose of this study was to determine the diversity of fish and also to determine the quality of water in the Cikapundung River, Bandung City. The method used in this study was a survey and exploration method, which involved collecting samples at five stations using umbrella traps, cast nets, and fishing gear in the morning and evening. The fish obtained were identified using the Fish Identification Guidebook, and the number of each type was calculated. The biotic data obtained were processed using the Shannon-Weiner diversity index (H'), Evenness index (E), Margalef Abundance index (Dmg), and Simpson Dominance index (C). In contrast, the abiotic data were sent to the water quality testing institution (LPKL). The study's results identified seven species from 5 families: Cyprinus sp., Ancistrus sp., Xiphophorus sp., Barbodes sp. According to the Shannon-Weiner index, the diversity of fish species in the Cikapundung River in Bandung City is relatively moderate, with a value (H') of 1.55. The results of water quality measurements of the Cikapundung River from LPKL based on the class II water quality standards of PP RI Number 22 of 2021 show that the condition of the river is in the moderately polluted category.

Use of lichens as bioindicators of contamination by agrochemicals and metals.

The presence or absence of lichens serves as an indicator of the condition of an ecosystem and the degree to which it is contaminated by various agents, such as agrochemicals and metals. Evaluating the use of lichens as bioindicators of agrochemical contamination could provide a more comprehensive perspective of current contamination levels. Monitoring was conducted over a 4-month period in two study areas: one was a well-conserved area contaminated by metals, and the other was an area surrounded by agricultural crops contaminated by agrochemicals. Data on the presence and abundance of lichens in each study area were recorded at 10 monitoring points, a procedure that was repeated 16 times (every 15days), and concentrations of heavy metals and "organophosphate" agrochemicals in the lichens collected were measured by means of Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) and Gas Chromatography (GC), respectively. Generalized linear mixed models were used to assess abundance and richness, while general linear mixed models were used to attain Shannon diversity and Simpson dominance indices. Moreover, a multivariate analysis was performed in order to compare the lichen communities in both areas. The results indicated differences between the area contaminated by metals and that contaminated by agrochemicals in terms of abundance and Simpson's dominance index, while no differences were found in the case of the richness and diversity models. The PERMANOVA analysis additionally showed differences between the lichen communities in the two areas. The results also demonstrated that Canoparmelia caroliniana bioaccumulated metals in both areas. The levels of barium, cadmium, and sodium were higher in the area contaminated by metals, while concentrations of chromium and copper were higher in the area contaminated by agrochemicals. Finally, the concentrations of agrochemicals were higher in the area contaminated by agrochemicals and included toxic substances such as Methylparathion and Parathion, which are prohibited in Ecuador. In conclusion, this research underscores the importance of lichens as precise indicators of environmental health and contamination by agrochemicals and metals.

Anti-seasonal flooding drives substantial alterations in riparian plant diversity and niche characteristics in a unique hydro-fluctuation zone.

Human-induced disturbances such as dam construction and regulation have led to widespread alterations in hydrological processes and thus substantially influence plant characteristics in the hydro-fluctuation zones (HFZs). To reveal utilization of limited resources and mechanisms of inter-specific competition and species co-existence of plant communities based on niche breadth and overlap under the different HFZs of the Three Gorges Reservoir (TGR) in China, we conducted a field investigation with 368 quadrats on the effects of hydrological alterations on plant diversity and niche characteristics. The results showed anti-seasonal flooding precipitated the gradual disappearance of the original diverse niches, resulting in the reduction of plant species richness and functional diversity and more obvious competition among plant species with similar resource requirements. Annuals, perennials and shrubs accounted for 71.23%, 27.39% and 1.37%, respectively, suggesting that annuals and flood-tolerant riparian herbs were favored under such novel flooding conditions. A consistent increase in species number, Shannon-Wiener diversity index and Simpson dominance index with altitude was inconsistent with hump-shaped diversity-disturbance relationship of the intermediate disturbance hypothesis, while the opposite trend was observed for the Pielou evenness index. This species distribution pattern might be caused by several synergetic attributes (e.g., the submergence depth, plant tolerant capacity to flooding, life form, dispersal mode and inter-specific competition). Vegetation types shifted from xerophytes to mesophytes and eventually to hygrophytes with the increasing flooding time in the HFZs. Hydrological alterations proved to be the paramount driver of vegetation distribution in the different HFZs. The niche analysis provided the first insights on the mechanisms of resource utilization and inter-specific competition, of which annuals could germinate quickly after soil drainage to achieve the greatest competitive advantages and occupy a larger niche space than other plants. Vegetation was still in the early stage of primary succession in the novel riparian forests. Therefore, vegetation restoration strategies should be biased towards herbaceous plants, due to annuals with better environmental adaptability, supplemented by shrubs and small trees. To establish a complete reference system for vegetation restoration, natural vegetation monitory plots in the different succession stages should be established in the different HFZs of the TGR, and their environmental conditions, community structures and inter-specific relationships further analyzed.

Structure of the macrozoobenthos community in Buai River, Pulau Tengah, Keliling Danau District, Kerinci Regency, Jambi Province

Background: Buai River is a river located in the village of Jembatan Merah Pulau Tengah, Keliling Danau District, Kerinci Regency, Jambi. Sungai Buai with topographic conditions in the form of a hilly highland area, surrounded by mountains and dense forests so that it has a heterogeneous microhabitat and is still natural for macrozoobenthos. Therefore, a study was conducted on the presence and structure of macrozoobenthos in the Sungai Buai area of Central Island. This study aims to analyze the structure of the macrozoobenthos community based on the composition of the macrozoobenthos species, density, diversity, dominance and distribution of macrozoobenthos in the waters of the Buai River. This research is expected to provide information in the form of scientific data and knowledge about the structure of the macrozoobenthos community in the waters of the Buai River to be used as comparative data for future research. This research was conducted from January to February 2022. Method: The research method used is a quantitative descriptive method, which is to describe and evaluate a symptom or event that appears systematically. Determination of research stations is done by purposive sampling method, which is taken five stations based on environmental baseline. Data analysis was carried out by calculating the composition, macrozoobenthos density, Diversity Index, Dominance Index and Community Similarity Index between stations. Findings: The results showed that there were 5 classes, 11 orders, 26 families and 42 genera. Diversity values ranged from 1,4 to 2,45 which was classified as moderate, the dominance ranged from 0.1 to 0.45, and the similarity of the macrozoobenthic community in Sungai Buai 60.71% - 82.54% the similarity of the macrozoobenthos was relatively the same with little organic pollution. Conclusion: Based on the structure of the macrozoobenthos community in the Buai River, Central Island, it can be concluded that the Buai Pulau Tengah River, Keliling Danau District, Kerinci Regency, Jambi Province is still classified as very good. Novelty/Originality of this Study: This study presents novel findings by revealing the structure of the macrozoobenthos community in a relatively undisturbed highland river surrounded by dense forests, which provide a unique heterogeneous microhabitat. It contributes original data on the species composition, density, diversity, and distribution of macrozoobenthos in this specific region, offering a baseline for future comparative studies.

Dominansi Bintang Laut (Asteroidea) di Pantai Awang Kabupaten Lombok Tengah

This study aims to determine the dominance of sea stars (Asteroidea) at Awang Beach, Central Lombok Regency. The research type is descriptive comparative. Sampling was conducted at three stations: Station I, Station II, and Station III, using the transect-quadrat method. Data collection techniques included direct observation and documentation. The parameter measured was sea star dominance. The results indicate that the sea star dominance index at the three stations is 0.576, categorized as low.

Moraceae diversity in the Universitas Sumatera Utara’s arboretum

The arboretum of the Universitas Sumatera Utara (USU) is an area for collecting and conserving tree species in North Sumatra. One of dominant family found in USU Arboretum is Moraceae. The objective of this reserach was to determine Moraceae diversity in the USU Arboretum. The census approach of vegetation analysis was used to determine the identity and abundance of Moracea. The research found 9 (nine) Moraceae species belongs to two genera in the USU arboretum, those were Ficus microcarpa, Ficus elastic, Artocarpus heterophyllus, Ficus padana, Ficus fistulosa, Artocarpus altilis, Ficus benjamina, Ficus ampelas and Ficus hispida. The species with the highest density value (57.92%) is Ficus hispida. The diversity index, richness index, and species dominance index were all quite low in the research location, with values of 1.455, 1.226, and 0.370, respectively. Meanwhile, the species evenness index at the research location is 0.662, which is classified into moderate. To improve the diversity of Moraceae in the USU arboretum, species enrichment activities are needed.

Community Structure of Mollusca (Gastropoda and Bivalvia) at Toronipa Beach

Toronipa Beach is known to have high biodiversity, especially in the Mollusca community such as Gastropoda and Bivalvia. However, research on the distribution and abundance of Mollusca species in this area, especially related to environmental changes, is still limited. To fill this gap, an analysis study was conducted on the structure of the Toronipa Beach Mollusca community as a basis for effective conservation efforts. Data were collected through purposive sampling methods at three different locations, then analyzed using the Shannon-Wiener Index method, evenness index, and dominance index. The results showed that the North of Toronipa Beach had the highest diversity with a Simpson index of 0.91, followed by the West with 0.76, and the East with 0.75. These differences in diversity reflect variations in microhabitats, such as substrates, water flow, and human activities, which affect the distribution and abundance of species. This study highlights the importance of proper management and conservation to maintain biodiversity in Toronipa Beach and provides a basis for further studies on the impacts of the environment and climate change on coastal ecosystems.

Evaluation of Rat Density and the Associated Factors in Leptospirosis Endemic Areas: The First Report on the Use of BI-Index

Introduction: Leptospirosis is a health problem in tropical countries where rats serve as the reservoir of Leptospira contamination. Previous investigations implementing the Bi-index to assess rat density in Leptospirosis endemic areas are highly limited. This study aimed to use the Bi-index in monitoring rat density and the associated factors in urban Leptospirosis endemic areas. Methods: Four endemic areas in Semarang City were selected as the study sites based on Leptospirosis data in Puskesmas Gayamsari. Live traps were positioned in one case house and 39-49 neighboring houses in a 100m radius, on three consecutive days. Trapped rats were collected for species identification, morphometrics evaluation, and calculation of Bi-index and rat indices, while environmental parameters were obtained through observation. Results and Discussion: 67.1% of participants were women, private employees, and aged 17-55, while trap success ranged from 2.5-26.5% with the Bi, diversity, dominance, and evenness indices of 0.02-0.32, 0.94-1.09, 0.36-0.44, and 0.79-0.96, respectively. Trapped species included Rattus norvegicus, Rattus tanezumi, and Mus musculus with proportions of 61.3%, 34.1%, and 4.7%, respectively. The presence of rats was associated with closeness to the river containing stagnant water, frequent flooding, water entering houses during floods, open trash bins, and rubbish bins around the houses. The high rat density, dominant species, and correlated environmental conditions are strategic targets in controlling Leptospirosis in Semarang City. Conclusion: The rat density (dominated by R. norvegicus) in Semarang City was correlated with water drainage and garbage management, hence further investigation was recommended to determine Leptospira bacterial infection in rodents.

Body Mass and Foot-dominance Disparities in the Foot Plantar Pressure Parameters of Older Women.

To examine the effects of foot dominance and body mass on foot plantar pressures in older women of regular, overweight, and obese weights. 96 female adults were divided into regular-weight group (68.30 ± 4.19 yr), overweight group (69.88 ± 3.76 yr), and obesity group (68.47 ± 3.67 yr) based on their body mass index scores. Footscan® plantar pressure test system was used to assess the dynamic plantar pressures, and parameters were collected from risk analysis, foot axis analysis, single foot timing analysis, and pressure analysis. (1) The local risks of lateral forefoot and midfoot, the minimum and maximum subtalar joint angles, the flexibility of subtalar joint, foot flat phase, as well as the average pressures on toes, metatarsals,, midfoot, and lateral heel, with the peak pressures on toe 2-5, metatarsal 2, metatarsal 5, midfoot, and lateral heel had significant within-subject differences. (2) The phases of initial contact and foot flat, the average pressures on toe 2-5, metatarsals, midfoot, and heels, with the peak pressures on metatarsal 1-4, midfoot, and heels exhibited significant between-subjects differences. (3) There was an interaction effect of foot dominance and body mass index on the flexibility of subtalar joint. The non-dominant foot works better for stability, especially when touching on and off the ground. The dominant foot works better for propulsion but is more susceptible to pain, injury, and falls. For obese older women, the forefoot and midfoot are primarily responsible for maintaining stability, but the lateral midfoot and hindfoot are more prone to pain and discomfort.

Domination index in graphs

The concepts of domination and topological index hold great significance within the realm of graph theory. Therefore, it is pertinent to merge these concepts to derive the domination index of a graph. A novel concept of the domination index is introduced, which utilizes the domination degree of a vertex. The domination degree of a vertex [Formula: see text] is defined as the minimum cardinality of a minimal dominating set (MDS) that includes [Formula: see text] Methods to find a MDS containing a particular vertex is also discussed in the study. The notion of domination degree and domination index are studied for graphs like complete graphs, complete bipartite, [Formula: see text] partite graphs, cycles, wheels, paths, book graphs, windmill graphs, Kragujevac trees. The study is extended to operation in graphs. Inequalities involving domination degree and already established graph parameters are discussed. An application of domination degree is discussed in facility allocation in a city.

Stand spatial structural diversity: Developing and validating a novel index

Numerous studies related to the diversity-productivity relationships have mainly focused on the effects of species diversity, function diversity, and nonspatial structural diversity (e.g., variations of diameter), but have overlooked the significant roles of spatial structural diversity. Therefore, the motivation of the present study was to develop a comprehensive index of stand spatial structural diversity (H′) by integrating the strengths of the Shannon-Wiener index and the quaternion joint probability distribution of commonly used neighborhood-based parameters, namely the uniform angle index (W), mingling index (M), diameter dominance index (U) and crowdedness index (C). The application abilities of the index were tested using ten 100 m ×100 m sample plots that were distributed in three different climate zones [4 plots in Greater Khingan Mountains (GKM), 2 plots in Lesser Khingan Mountains (LKM), 4 plots in Changbai Mountains (CBM)] in Heilongjiang Province, northeast China. Meanwhile, the potential driving factors on stand spatial structural diversity were also detected using stepwise regression and hierarchical partitioning techniques based on 3000 simulated stands. The results indicated that the average values of H′ at GKM, LKM, and CBM were 0.8436, 0.8079, and 0.8098, suggesting that the stand spatial structural diversities of the forests in GKM were notably higher than those in LKM and CBM. The characteristics of M, C, and W emerged as the three most influential factors driving stand spatial structural diversity. This study contributes significantly not only by providing an effective index for measuring stand spatial structural diversity, but also by streamlining the complex decision processes associated with optimizing stand spatial structure.

Structure of Fish Communities Results of Fishermen's Catches in The Waters Around Mangroves on The Coast Lembar of West Lombok

Fish have an important role as an ecological and economic function. This research aims to determine the structure of the fish community based on fishermen's catches in the waters around the coastal mangroves of West Lombok. Data collection uses survey and observation methods. Next, data analysis of fish diversity values ​​used the Shannon-Wiener Index (H'), Uniformity Index (E), and Dominance Index (D). The results of this research have found 40 species, consisting of 5,012 individuals in 20 families. Furthermore, the fish species that has the highest number of individuals is Nemipterus Marginatu (0.144%) of the total number of individuals. Meanwhile, the fish species with the lowest number of individuals is Neotygon Kuhlii (0.01%). The value (H') of fish species in landings in the northern part is higher with a value (H') of 2.946, while in landings in the southern part it is 2.839, and the uniformity index (E) of fish in the northern part is 0.074, while landings in the southern part are 0.074. 0.024, Meanwhile the Fish Dominance Index (D) in the northern part is smaller with a value of 0.071 compared to landings in the southern part of 0.084. Conclusion of research on the structure of fish communities in waters around mangroves with the composition of the most Nemipterus Marginatu species and the least Neotygon Kuhlii. The level of fish species diversity is in the medium category with the level of uniformity and dominance also in the medium category.

The nature of vegetation cover and small mammal community structure (on the example of Nizhny Novgorod)

The spatial distribution of Apodemus species (yellow-necked, field, and small forest mice) was studied on the example of the protected area «Oak forest of National Research Lobachevsky State University of Nizhny Novgorod Botanical Garden». Twelve plant associations with non-moral character and representing derivatives of the indigenous type of vegetation were studied. Environmental conditions assessed by the Ellenberg phytoindication method affect the distribution of small mammals in space indirectly. The nature of vegetation cover is more significant. When projective cover increases, the abundance of both small woodland and field mice increases. The strategy of Apodemus agrarius appears to be similar to that of Apodemus uralensis, a species that shows stenobiontic traits in the studied PA. At the same time, insignificant anthropogenic load, a marker of which is the presence of Urtica dioica ruderal species, leads to an increase in the mosaic of vegetation cover, which has a positive effect on the abundance of these small mammal species. A moderate increase in the Berger-Parker dominance index for vegetation cover is positively associated with the confinement of micromammals. In addition, in the conditions of the recreational zone of the upland part of N. Novgorod, Apodemus agrarius prefers areas of old-growth broadleaved forest, not showing the features of anthropophily.

Bird-Ecosystem Relationship in an Urbanizing Habitat: Implications for Conservation and Ecosystem Stability

This study explores the association between birds and their urbanizing ecosystems. The study area was divided into 4 quadrats of area 2700 m2 each. Bird species as well as number of individuals of each species were counted using the Line Transect Method. Statistical analysis of the data was performed using Windows Microsoft Excel and SPSS v.28. The investigation revealed a significant correlation (P < 0.05) between bird species and the four distinct sites within the study area. These sites exhibit variations in vegetation composition and include notable features like water bodies. The findings underscore the heavy reliance of certain bird species in this region on specific types of vegetation for their survival and well-being. Removing even a single plant species could potentially disrupt the entire ecosystem. The study documented the presence of 42 bird species across 30 families, including one vulnerable species. Both local and seasonal migratory birds were observed during the research. Although the study identified a decline in bird diversity within the study area, it remains species-rich, displaying moderate to high diversity (Simpson’s Dominance Index: 0.0319; Margalef’s Richness Index: 4.0754). This research emphasizes the critical importance of conserving bird species and their associated vegetation to maintain ecosystem integrity. Strategic sustainable development practices along with habitat enrichment for birds is recommended to maintain the valuable avifaunal diversity of the study area. By highlighting the intricate relationship between birds and their habitat, the study highlights the significance of conservation efforts in safeguarding the overall health of the ecosystem.

Stress path-based compressive strength model of FRP-confined recycled aggregate concrete

The compressive strength model of fibre-reinforced polymer (FRP) confined recycled aggregate concrete (RAC) is important in practical engineering designs. The existing research has showed that the compressive strength of FRP-confined RAC can be predicted by the models for FRP confined natural aggregate concrete (NAC). However the accuracy of existing compressive strength models for FRP-confined NAC vary greatly because of the unclear understanding of the confinement mechanisms. Previous research has shown that the axial stress of confined concrete tends to be path-dependent. In this study, a confining stress path-based compressive strength model of FRP-confined RAC is proposed based on theoretical analyses of the confining stress path of FRP-confined RAC. In the proposed model, an effect index is determined to express the influence of confining stress path on the compressive strength. The relationship between the effect index and confinement ratio and that between lateral stress dominant index and confinement ratio are obtained. The proposed model is verified by comparison with previous experimental test results and those predicted by existing representative models. It is found that the compressive strength of FRP-confined RAC is path-dependent for small confinement ratios (less than 0.43) and path-independent for large confinement ratios (larger than 0.43).

Population Structure and Regeneration Status of Tree Species in Eastern Himalaya, Mahananda Wildlife Sanctuary, West Bengal

The study provides information on the tree diversity, stand structure, and regeneration pattern of the Mahananda Wildlife Sanctuary. Tree diversity and its relation to habitat have been explored using 88 plots with dimensions of 50 × 20 m. A survey of 8.8 ha of the study area was conducted during the fieldwork. Plants with a circumference of 30 cm and above were enumerated as trees, while plants with a circumference between 30–10 cm were considered juveniles (saplings and seedlings). A total of 1677 tree individuals belonging to 67 genera of 43 families were recorded. Five species - Shorea robusta, Schima wallichii, Acer oblongum, Magnolia pterocarpa and Ficus benghalensis contributed to the maximum stand density and species richness. The total stand density per hectare was recorded as 2160 individuals/ha, with a total basal area of 8.86 m²/ha. The regeneration status has been evaluated as ‘Good’, with 4336 regenerating individuals/ha recorded during the study. Diversity indices were calculated: Shannon-Weiner index was 3.607, Simpson dominance index was 0.937, Margalef index was 11.45, and evenness was 0.428.

Are Users Good Assessors of Social Dominance in Domestic Horses?

Horse users and caretakers must be aware of the risks of mixing social groups. The current study investigated whether eight equine practitioners can assess the social dominance rank of 20 horses. The horses' feeding time and agonistic/aggressive and submissive behaviours were observed during the feed confrontation test, and the dominance index (DI) was calculated. Kendal's W, Spearman correlations and factor analysis were applied to test the raters' agreement, the relationship between dominance ranks and the behavioural variables, and to determine the clustered behaviours. The agreement between all raters in the classification of dominance order ranged from moderate to perfect. The ranking by every rater was strongly and negatively correlated with the time of eating in feed confrontation tests and with the DI, evidencing shorter feeding times for more submissive horses. The withdrawal of the horse when threatened was the behavioural variable that was most often correlated with raters' ranking. The current study confirmed the abilities of practitioners to categorise the horses under their care according to their social interactions. Additionally, rolling when denied access to feed was proposed as frustration-releasing (redirected) behaviour.

Diversity pattern of ichthyofaunal assemblage in South-central coastal region of Bangladesh

The south-central coastal waters of Bangladesh are recognized as one of the foremost aquatic biodiversity hotspots despite severe anthropogenic and environmental hazards to natural fishery resources. Therefore, this study was undertaken to examine the current status of fish faunal diversity and evaluate the condition and conservation status of fish in the rivers spanning the south-central coastal region of Bangladesh. During the research period, spanning from July 2021 to February 2022, a total of 105 fish faunal species belonging to 84 genera, 50 families, and 14 orders were documented. The order Perciformes (27.62%) was found to be the most diverse fish group, followed by Cypriniformes and Scombriformes (12.38%), Siluriformes and Clupeiformes (11.43%), Synbranchiformes and Pleuronectiformes (3.81%). According to the International Union for Conservation of Nature (IUCN) Red List classification, 52 species recorded from the studied areas were determined to be of Least Concern, while 11 species were Vulnerable, 14 species were classified as Endangered, and 7 species are recognized as Critically Endangered. In order to assess the species diversity, richness, and evenness of the fish assemblage in the sampling areas, four diversity indices, viz. the Shannon-Wiener index (H), Simpson’s dominance index (D), Simpson’s index of diversity (1-D), and Margalef’s index (d), were applied. Their overall values were 3.39–3.59, 0.05–0.07, 0.95–0.94, and 7.67–8.75, respectively. All of the species were more or less evenly distributed throughout the three sites, with Kalapara having the most even distribution. Several anthropogenic and natural attributes that contribute to decline in fish diversity were recorded using a survey questionnaire which revealed that management and conservation measures should be taken with utmost urgency.

Keragaman Arthropoda pada Teknologi Bujangseta di Tanaman Jeruk Siam

Bujangseta is a technology used throughout the year to produce citrus fruits. This technology has economically succeeded in increasing the income of citrus farmers by 23.5%. Sustainable management of bujangseta technology is neede, one of which is maintaining the sustainability of the agroecosystem. A stable agroecosystem ensures the availability of ecosystem services through nutrient cycling and the natural control of pest and disease populations. The stability of agroecosystems is coherent with the high biodiversity of arthropods. This study aims to evaluate the effect of applying the citrus plant bujangseta in Karangwidoro village and Krajan village, Dau District, Malang Regency, East Java, from June to December 2022. The two application methods were light trapping (lighttrap) and pit trap (pitfall glass), and the results were analyzed using a t-test. The diversity index, species richness index, species evenness index, and dominance index were calculated. The results showed that the detrivores of the Collembola group dominated the diversity of arthropods, the primary pest of the Diaphorina citri, and the predatory arthropods of Paederus sp. and Braconidae. Diversity and community structure of arthopods indicated there at significant differences in diversity, dominance, evenness, and species richness in those two locations. Bujangseta in the Krajan has a higher community structure compared to the Karangwidoro, showing that the ecosystem at the Krajan location is better preserved. Keywords: arthropods, bujangseta, citrus, community structure

Tests for almost stochastic dominance

We introduce a 2-dimensional stochastic dominance (2DSD) index to characterize both strict and almost stochastic dominance. Based on this index, we derive an estimator for the minimum violation ratio (MVR), also known as the critical parameter, of the almost stochastic ordering condition between two variables. We determine the asymptotic properties of the empirical 2DSD index and MVR for the most frequently used stochastic orders. We also provide conditions under which the bootstrap estimators of these quantities are strongly consistent. As an application, we develop consistent bootstrap testing procedures for almost stochastic dominance. The performance of the tests is checked via simulations and the analysis of real data.