Underwater video surveys provide a more complete picture of littoral fish populations than seine samples in clear Florida springs

2019 ◽  
Vol 70 (8) ◽  
pp. 1178
Author(s):  
Kirsten Work ◽  
Coramarie Jifu Jennings
Keyword(s):  
Species Richness ◽  
Sampling Method ◽  
Sampling Methods ◽  
Water Clarity ◽  
Fish Abundance ◽  
Video Assessment ◽  
Species Richness And Diversity ◽  
Abundance And Diversity ◽  
Number Of Individuals ◽  
Better Than

Traditional fish-sampling methods may be problematic because of public use or safety concerns. In this study, we compared one common sampling method with video assessment of fish abundance and diversity in three springs that differed in water clarity and structure. At each of four or five sites per spring, we placed one GoPro camera on each bank for 12min and followed the filming with seine sampling. On the video, we counted the maximum number of individuals of each species observed within one frame (MaxN) and summed these counts to produce an estimate of fish abundance (SumMaxN). Then we compared abundance (SumMaxN), species richness and diversity between seine and video samples across all three springs. Video produced higher estimates of abundance (SumMaxN), species richness, and diversity than did seine sampling. However, this effect was largely confined to species richness and diversity differences between sample methods in the structurally complex spring; differences were subtle or non-existent in the low-structure spring and in the turbid spring. In all three springs, video captured relatively more centrarchids; these taxa were captured only rarely in seine samples. Therefore, video sampling performed as well or better than did seine sampling for fish-assemblage assessment in these clear springs.

scholarly journals HSDP: A Hybrid Sampling Method for Imbalanced Big Data Based on Data Partition

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Liping Chen ◽  
Jiabao Jiang ◽  
Yong Zhang
Keyword(s):  
Big Data ◽  
Sampling Method ◽  
Sampling Methods ◽  
Data Partition ◽  
Minority Class ◽  
F Measure ◽  
Better Than ◽  
Hybrid Sampling

The classical classifiers are ineffective in dealing with the problem of imbalanced big dataset classification. Resampling the datasets and balancing samples distribution before training the classifier is one of the most popular approaches to resolve this problem. An effective and simple hybrid sampling method based on data partition (HSDP) is proposed in this paper. First, all the data samples are partitioned into different data regions. Then, the data samples in the noise minority samples region are removed and the samples in the boundary minority samples region are selected as oversampling seeds to generate the synthetic samples. Finally, a weighted oversampling process is conducted considering the generation of synthetic samples in the same cluster of the oversampling seed. The weight of each selected minority class sample is computed by the ratio between the proportion of majority class in the neighbors of this selected sample and the sum of all these proportions. Generation of synthetic samples in the same cluster of the oversampling seed guarantees new synthetic samples located inside the minority class area. Experiments conducted on eight datasets show that the proposed method, HSDP, is better than or comparable with the typical sampling methods for F-measure and G-mean.

On the Effectiveness of Hand Collection to Complement Baits When Studying Ant Vertical Stratification in Tropical Rainforests

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 213
Author(s):  
Reuber Antoniazzi ◽  
Diana Ahuatzin ◽  
Jaime Pelayo-Martínez ◽  
Liliana Ortiz-Lozada ◽  
Maurice Leponce ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Forest Floor ◽  
Sampling Method ◽  
Tropical Rainforest ◽  
Sampling Methods ◽  
Search Time ◽  
Tropical Rainforests ◽  
Additional Advantage ◽  
Key Factor

Choosing an appropriate sampling method to study ants is a key factor since distinct sampling methods can capture distinct ant fauna and, therefore, leading to bias in the interpretation and conclusion of the patterns observed. Despite it is well known that the ant fauna is vertically stratified, some of the sampling methods cannot be used throughout the whole vertical stratum (e.g., fogging and Winkler extractor). Here we compared the complementarity of hand collecting and baiting (with tuna or honey) in ant surveys focused on the stratification of the ant fauna in a tropical rainforest in Mexico. We found a total of 44 ant species, belonging to 17 genera and five subfamilies. The three sampling methods were clearly complementary at both the forest floor and canopy levels, even with as little as 10 minutes of search time for hand collecting. The ant species composition differed among sampling methods at both vertical strata. Hand collecting yielded higher ant species richness and more exclusive species than either bait at both vertical strata, but both tuna and honey baits also led to the detection of some (though fewer) exclusive ant species. The combination of hand collecting, tuna, and honey baits should thus be considered complementary tools for ant inventories, since using the two methods together yielded more complete inventories at both vertical strata. An additional advantage is that both methods can be used in both strata, ensuring that data in different vertical strata are comparable and allowing more reliable comparisons among these different habitats.

scholarly journals Relationships between Plant Diversity and Grasshopper Diversity and Abundance in the Little Missouri National Grassland

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
David H. Branson
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Diversity ◽  
Plant Species Richness ◽  
Coarse Grained ◽  
Grasshopper Species ◽  
Species Richness And Diversity ◽  
Western North Dakota ◽  
Abundance And Diversity ◽  
Species Richness And Abundance

A continuing challenge in orthopteran ecology is to understand what determines grasshopper species diversity at a given site. In this study, the objective was to determine if variation in grasshopper abundance and diversity between 23 sites in western North Dakota (USA) could be explained by variation in plant species richness and diversity. In this system with relatively low plant diversity, grasshopper species richness and abundance were not significantly associated with plant species richness in either year. Although a number of significant associations between plant diversity and grasshopper diversity were found through regression analyses, results differed greatly between years indicating that plant species richness and diversity did not lead to strong effects on grasshopper diversity metrics. Plant species richness appears to be too coarse grained to lead to accurate predictions of grasshopper species richness in this system dominated by generalist grasshopper species.

scholarly journals Bees (Hymenoptera, Apoidea) in an Ecotonal Cerrado-Amazon Region in Brazil

Sociobiology ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 457
Author(s):  
Rony Peterson Santos Almeida ◽  
Filipe Viegas Arruda ◽  
Daniel Paiva Silva ◽  
Beatriz Woiski Teixeira Coelho
Keyword(s):  
Species Richness ◽  
Sampling Method ◽  
Sampling Methods ◽  
Amazon Region ◽  
The State ◽  
Species Specificity ◽  
Pitfall Traps ◽  
Different Seasons ◽  
Accumulation Curves ◽  
Pan Traps

Little is known about the distribution of organisms in transitional areas, overall because of the lack of understanding regarding each species’ specificity to the diversity of microhabitats found in these areas and effective ways to sample organisms in these regions. Therefore, in this study we aimed to inventory the bee species in a transitional Cerrado-Amazon area in the state of Pará, Brazil, evaluating the effects of three different sampling methods. We used six fragments, sampled in two different seasons with three sampling methods (arboreal pitfalls with urine, scent traps, and pan traps). The specimens were identified and we used accumulation curves to measure the effectiveness of each method. In total, we sampled 68 bee species, where 53 were exclusively from one single sampling method. The pitfall traps were those with reached the highest species richness among all three sampling methods analyzed, followed by the scent traps and pan traps, respectively. Despite the efficiency and generality of the bee groups we found, the pitfall method does not cover specific bee groups as the Euglossini bees, almost exclusively attracted to scent traps. Therefore, we suggest that studies using pitfalls with urine should be performed in other biomes to evaluate the efficiency of this method in future bee surveys.

scholarly journals Field sampling methods for investigating forest-floor bryophytes: Microcoenose vs. random sampling

2018 ◽  
Vol 70 (3) ◽  
pp. 589-598
Author(s):  
Milos Ilic ◽  
Ruzica Igic ◽  
Mirjana Cuk ◽  
Dragana Vukov
Keyword(s):  
Species Richness ◽  
Random Sampling ◽  
Forest Floor ◽  
Sampling Method ◽  
Sampling Methods ◽  
Diversity Index ◽  
Systematic Sampling ◽  
Field Sampling ◽  
Beech Forests ◽  
Quadrat Size

Because of the high importance of bryophytes in forest ecosystems, it is necessary to develop standardized field sampling methodologies. The quadrat method is commonly used for bryophyte diversity and distribution pattern surveys. Quadrat size and the position of quadrats within the studied area have a significant influence on different analyses. The aim of the present study was to define the minimum quadrat size appropriate for sampling ground bryophytes in temperate beech forests, to compare two different field sampling methods for research on ground bryophytes, the random and microcoenose methods; and to test the adequacy of the microcoenose sampling method in temperate beech forests. Research was carried out on Fruska Gora mountain (Serbia) at four different sites. All sites contained temperate broadleaf forest vegetation, predominantly Fagus sylvatica, but also included various other tree species. Systematic sampling based on nested quadrats was used to determine the minimum sampling area. Random sampling was performed using 10 or 20 microplots (minimum area quadrat), randomly located within 10x10 m plots. Microcoenose sampling is a systematic sampling method based on the fact that every bryophyte fragment on the forest floor is a separate microcoenose. These methods were compared using the following criteria: species richness; Shannon?s diversity index and evenness measure; coverage of dominant species, and the time needed for sampling. The microcoenose sampling method has proven to be highly applicable in temperate beech forests in terms of species richness and diversity, in contrast to random sampling, which was not suitable for bryophyte flora with a patchy distribution.

scholarly journals The abundance and diversity of grasshopper communities in relation to elevation and land use in Malang, Indonesia

2020 ◽  
Vol 21 (12) ◽  
Author(s):  
Amin Setyo Leksono ◽  
Bagyo Yanuwiadi ◽  
Aminudin Afandhi ◽  
MOHAMMAD FARHAN ◽  
Anisa Zairina
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Species Diversity ◽  
Altitudinal Gradient ◽  
Landsat Imagery ◽  
Abiotic Factors ◽  
Significant Negative Correlation ◽  
Grasshopper Species ◽  
Species Richness And Diversity ◽  
Abundance And Diversity

Abstract. Leksono AS, Yanuwiadi B, Afandhi A, Farhan M, Zairina A. 2020. The abundance and diversity of grasshopper communities in relation to elevation and land use in Malang, Indonesia. Biodiversitas 21: 5614-5620. Ecological factors include interactions of the community members with numerous biotic and abiotic factors such as temperature, humidity, precipitation, light intensity, and seasonality show an altitudinal gradient. Most grasshopper species play a role as herbivores and are a good source of protein for other animals such as amphibians, small reptiles, birds, and small mammals. This study aimed to analyze variations in the abundance, richness, and diversity of grasshopper species along an altitudinal gradient. This research was conducted in five locations in Malang District, East Java, Indonesia, namely Bantur, Sumber Pujung Lawang, Pujon, and Poncokusumo. Grasshopper sampling was carried out by the sweeping method using an insect net. Sweepings were carried out on four plots with each plot size of 2 x 10 m2. Sampling was conducted four times from June to August 2020. The data were analyzed using the Shannon Wiener index (diversity analysis) and the Bray-Curtis index. The differences between locations were tested by one-way analysis of variance. Land use was analyzed by ArcGIS, using Landsat imagery 8. The abundance of grasshoppers had a significant negative correlation with elevation. That correlation was positive to species richness and diversity of grasshoppers. That with species diversity was significant, while that with species richness was not significant. The greatest abundance of the grasshopper was found in the middle elevation in Lawang (19.39 ± 2.12). In contrast, the highest species richness and diversity were found in the highest elevation in Poncokusumo (richness = 15.75 ± 1.60 and H '= 2.58 ± 0.11). Land use variation was not significant on abundance, species, richness, and diversity of grasshoppers. Interestingly, the high similarity of the grasshopper compositions in low elevation habitats was detected, indicating that land use in the low land area was remarkable. The abundance of grasshopper had a significant positive correlation with temperature but negatively correlated with humidity. There was no significant correlation among species richness, species diversity with temperature and humidity.

scholarly journals Diversity of Ants (Hymenoptera, Formicidae) in Two Forest Sites from Kabylia of Djurdjura, Northern Algeria

Sociobiology ◽  
2021 ◽  
Vol 68 (3) ◽  
pp. e6232
Author(s):  
Sadou Sid-Ali ◽  
Sadoudi Ali-Ahmed Djamila ◽  
Metna Ali-Ahmed Fatiha ◽  
Ourrad Ouiza ◽  
Slimani Said
Keyword(s):  
Species Richness ◽  
Sampling Methods ◽  
Diversity Index ◽  
Species Occurrence ◽  
Local Site ◽  
Northern Algeria ◽  
Forest Sites ◽  
The Difference ◽  
Study Sites ◽  
Number Of Individuals

The current study deals with the diversity of ants (Hymenoptera, Formicidae) in Kabylia of Djurdjura. It has been carried out in two forest sites from the localities of Azeffoun and Assi-Youcef, Tizi Ouzou (northern Algeria). Two sampling methods were adopted: manual capture and pitfall traps. Various community metrics were used as key elements to assess ant biodiversity within the two study sites. They included the species richness, the relative abundance, the constancy, and the Shannon-Weaver and equitability indices. Our inventory allowed identifying 24 species belonging to 12 genera and three subfamilies, which are the Myrmicinae (58%), the Formicinae (34%), and the Dolichoderinae (08%). The highest species richness was registered for the two first subfamilies, while the subfamily Dolichoderinae dominated numerically. The Site of Azeffoun, which is more submitted to human activities, recorded higher values in the number of individuals, the species richness, and the Shannon-Weaver diversity index. However, the difference between the two sites consisted mainly of the rare species, such as Crematogaster laestrygon, Goniomma sp. and Palagiolepis sp., which were present in the Azeffoun site. The local site conditions certainly have played a key role in ant species occurrence within the two study areas. Azeffoun is more disturbed than Assi-Youcef, resulting in the recruitment of much more rare and accidental species in the first site. In contrast, the rate of accessory to omnipresent species is substantially higher in Assi-Youcef, which recorded a high species evenness. To the best of our knowledge, this is the first study to report the ant genus Formica in Kabylia of Djurdjura.

Diptera (Dryomyzidae, Fanniidae, Muscidae, Piophilidae) Associated With Pig Carcasses in a Forest Habitat of Poland: Sex-Related Patterns of Visitation and Effectiveness of Sampling Methods

2022 ◽  
Author(s):  
Daria Bajerlein ◽  
Mateusz Jarmusz ◽  
Aleksandra Gregor ◽  
Andrzej Grzywacz
Keyword(s):  
Forensic Entomology ◽  
Sampling Method ◽  
Sampling Methods ◽  
Sex Ratios ◽  
Pitfall Traps ◽  
Appearance Time ◽  
Long Time ◽  
Pig Carcasses ◽  
Number Of Individuals

Abstract Our knowledge on many necrophilous dipterans was limited for a long time mainly due to taxonomic issues. Therefore, findings on the sex-related associations with pig carcasses in Dryomyzidae, Fanniidae, Muscidae, and Piophilidae are presented. Moreover, the effectiveness of pitfall traps and sweep nets in fly sampling were compared, since the correct method of collecting insects is critical for the development and application of entomological tools for forensic purposes. The trapped numbers of all species differed significantly in respect to both sexes. The sex ratios were strongly female-biased in most species of Muscidae and in Fanniidae. More females were also collected in Piophilidae, but the proportion of males was higher when compared to muscids. Within Dryomyzidae, the sex ratio differed according to species. Only Dryomyza flaveola (Fabricius, 1794) (Diptera: Dryomyzidae) and Muscina pascuorum (Meigen, 1826) (Diptera: Muscidae) had male-biased sex ratios. Differences in residency patterns between sexes in Stearibia nigriceps (Meigen, 1826) (Diptera: Piophilidae), Liopiophila varipes (Meigen, 1830) (Diptera: Piophilidae), and D. flaveola were statistically insignificant. All studied species were recorded for each sampling method. The effect of the sampling method on the number of individuals was statistically significant for all dipterans but Piophilidae. Pitfall traps outcompeted the aerial sweep net in representing Dryomyzidae and Muscidae, whereas both methods were almost equally effective in the collection of Piophilidae. A varied effectiveness of sampling methods was observed in Fanniidae. The sampling method significantly affected the determination of the appearance time of flies on carcasses, but the effect of species and sampling method was insignificant. Implications for forensic entomology are discussed.

scholarly journals Diversity of parasitoid Hymenoptera in banana germplasm plantation Yogyakarta

2019 ◽  
Vol 23 (1) ◽  
pp. 26
Author(s):  
Ichsan Luqmana Indra Putra
Keyword(s):  
Sampling Method ◽  
Sampling Methods ◽  
Direct Method ◽  
Wiener Index ◽  
Sampling Point ◽  
Sampling Points ◽  
Index Value ◽  
Number Of Individuals ◽  
Pan Traps

Banana is one of the fruits in Indonesia. The development of its production in Indonesia has increased. However, there are several factors that can reduce the production, one of which is pests. Pests on bananas can be controlled with natural enemies, one of which is parasitoid. The study aimed to calculate the diversity and abundance of parasitoids in the Yogyakarta banana germplasm plantation. The research was carried out in an area of approximately 2 Ha from April to June 2018 with sampling taken once a week. Sampling method used was in the form of transect. The determination of the transect point is determined as far as 500m between sampling points. At each sampling point carried out 2 sampling methods. Direct method by taking pests on 3 banana plants at each point and indirect with insect net and yellow pan traps. The results found that Shannon-Wiener Index value was 3.29. 22 Hymenoptera parasitoid families were found with the highest morphospecies were superfamily Chalcidoidea and the highest number of individuals were Scelionidae.

scholarly journals Implicitly adaptive importance sampling

2021 ◽  
Vol 31 (2) ◽  
Author(s):  
Topi Paananen ◽  
Juho Piironen ◽  
Paul-Christian Bürkner ◽  
Aki Vehtari
Keyword(s):  
Importance Sampling ◽  
Sampling Method ◽  
Sampling Methods ◽  
Probability Distributions ◽  
Adaptive Importance Sampling ◽  
Importance Sampling Method ◽  
Leave One Out ◽  
Standard Probability ◽  
Better Than ◽  
Current Proposal

AbstractAdaptive importance sampling is a class of techniques for finding good proposal distributions for importance sampling. Often the proposal distributions are standard probability distributions whose parameters are adapted based on the mismatch between the current proposal and a target distribution. In this work, we present an implicit adaptive importance sampling method that applies to complicated distributions which are not available in closed form. The method iteratively matches the moments of a set of Monte Carlo draws to weighted moments based on importance weights. We apply the method to Bayesian leave-one-out cross-validation and show that it performs better than many existing parametric adaptive importance sampling methods while being computationally inexpensive.

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