Estimating the species number and cover of a mangrove-root community: a comparison of methods

1992 ◽  
Vol 43 (4) ◽  
pp. 707 ◽  
Author(s):  
H Diaz ◽  
JE Conde ◽  
B Orihuela
Keyword(s):  
Sample Size ◽  
Sampling Design ◽  
Sampling Methods ◽  
Computer Hardware ◽  
Species Number ◽  
Mangrove Root ◽  
Mangrove Roots ◽  
Basic Features ◽  
Combined Strategy ◽  
Video Material

Methods and designs have been validated for sampling coral reefs and reef-associated communities, but the accuracy and equivalence of results obtained from studies of mangrove-root communities can not be assured. Thus, it is convenient to establish the accuracy and reliability of sampling methods on a practical basis. Line interception, point interception, and quadrat sampling were used to estimate several basic features of the community associated with mangrove roots. Species-number estimates, cover estimates, sampling efforts, and some statistical properties of the three methods were compared. A sampling design should be chosen if it yields estimates with the greatest accuracy at the lowest cost. Results showed that sampling of mangrove roots could start by using 4 × 4-cm quadrats with a mean sample size of 50 for detecting the number of species, and for establishing species cover it appears that the point-interception method with a sample size of 50 would be appropriate. The effort involved in such a sequence would be approximately 10 h for 20 roots. This combined strategy is clearly laborious and time-consuming in comparison with the use of just a 200-point interception, which would require only 3.25 h for the same number of roots. Although it would cost more than the above methods, a fast and accurate technique based upon existing computer hardware to estimate cover from photographic or video material would result in a census of the whole community. This might prove to be a reliable way to approach the problem.

scholarly journals Monitoring field establishment of the emerald ash borer biocontrol agent Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae): Sampling methods, sample size, and phenology

2021 ◽  
Vol 156 ◽  
pp. 104535
Author(s):  
Toby R. Petrice ◽  
Leah S. Bauer ◽  
Deborah L. Miller ◽  
John S. Stanovick ◽  
Therese M. Poland ◽  
...  
Keyword(s):  
Sample Size ◽  
Biocontrol Agent ◽  
Sampling Methods ◽  
Emerald Ash Borer

scholarly journals Topological and Metagenomic Evidence For Intensified Bacterial-Fungal Interactions in Mangrove Root Interior

2021 ◽  
Author(s):  
Zhengyuan Zhou ◽  
Ruiwen Hu ◽  
Yanmei Ni ◽  
Wei Zhuang ◽  
Zhiwen Luo ◽  
...  
Keyword(s):  
Plant Performance ◽  
Sequencing Technologies ◽  
Mangrove Root ◽  
Domain Interactions ◽  
Network Topologies ◽  
Mangrove Roots ◽  
Metagenome Sequencing ◽  
Underlying Mechanisms ◽  
Bacteria And Fungi ◽  
Fungal Interactions

Abstract Background: Plant roots host a repertoire of bacteria and fungi, whose ecological interactions could improve their functions and plant performance. However, potential interactions and underlying mechanisms remain largely unknown in root-associated microbial communities at a continuous fine-scale. Results: We analyzed microbial intra- and inter-domain network topologies, keystone taxa, and interaction-related genes across four compartments (non-rhizosphere, rhizosphere, episphere and endosphere) from a soil-mangrove root continuum, using amplicon and metagenome sequencing technologies. We found that both intra- and inter-domain networks displayed notable differences in the structure and topology across four compartments. Compared to three peripheral compartments, the endosphere was a distinctive compartment with more intensive interactions in bacterial-fungal network than in bacterial or fungal network, which could be related to three bacterial keystone taxa (Vibrio, Anaerolineae and Desulfarculaceae) detected in the endosphere as they are known to intensify inter-domain interactions with fungi and stimulate biofilm formation. Also, high abundances of genes involved in cell-cell communications by quorum sensing (rhlI, lasI, pqsH and lasR) and aerobic cobamide biosynthesis (cobG, cobF and cobA) were detected in the endosphere.Conclusions: Our results reveal intensified inter-domain interactions of endophytes in the mangrove roots, creating a distinct micro-environment to promote a biofilm life-style.

Optimal design with variable cost and precision requirements

1989 ◽  
Vol 19 (12) ◽  
pp. 1591-1597
Author(s):  
Margaret Penner
Keyword(s):  
Biological Sciences ◽  
Optimal Design ◽  
Sample Size ◽  
Design Theory ◽  
Sampling Design ◽  
Unit Cost ◽  
Evaluation Process ◽  
Variable Cost ◽  
Design Flexibility ◽  
The Cost

A method for incorporating variable costs and differing precision requirements into optimal design theory is developed and discussed. In many studies and experiments, particularly in the biological sciences, the cost of each observation can vary considerably depending on the attributes of the sample. Ignoring observation costs leads to designs that maximize precision for a given sample size. However, by incorporating costs, efficiency is maximized by optimizing precision per unit cost. An example is presented that demonstrates the efficiency of a weighted optimal design in comparison with several alternatives. The weighted optimal design is most efficient at meeting the experimenter's precision objectives. Comparing designs allows the introduction of additional criteria such as design flexibility into the evaluation process. Explicitly incorporating both cost and precision in the search for a sampling design ensures time is wisely spent considering study objectives, including precision requirements.

scholarly journals Evaluating Sampling Methods for Content Analysis of Twitter Data

2018 ◽  
Vol 4 (2) ◽  
pp. 205630511877283 ◽  
Author(s):  
Hwalbin Kim ◽  
S. Mo Jang ◽  
Sei-Hill Kim ◽  
Anan Wan
Keyword(s):  
Social Media ◽  
South Carolina ◽  
Sample Size ◽  
Random Sampling ◽  
Sampling Methods ◽  
Empirical Studies ◽  
Simple Random Sampling ◽  
Media Content ◽  
Twitter Data ◽  
Gubernatorial Election

Despite the existing evaluation of the sampling options for periodical media content, only a few empirical studies have examined whether probability sampling methods can be applicable to social media content other than simple random sampling. This article tests the efficiency of simple random sampling and constructed week sampling, by varying the sample size of Twitter content related to the 2014 South Carolina gubernatorial election. We examine how many weeks were needed to adequately represent 5 months of tweets. Our findings show that a simple random sampling is more efficient than a constructed week sampling in terms of obtaining a more efficient and representative sample of Twitter data. This study also suggests that it is necessary to produce a sufficient sample size when analyzing social media content.

Volumetric Three-Componential Velocity Measurements (V3V) of Flow Structure Behind Mangrove-Root Type Models

2020 ◽  
Author(s):  
Amirkhosro Kazemi ◽  
Eduardo E. Castillo ◽  
Oscar Curet ◽  
Ruben Hortensius ◽  
Pothos Stamatios
Keyword(s):  
Flow Structure ◽  
Vortex Structure ◽  
Streamwise Velocity ◽  
Circular Cylinders ◽  
Complex Flow ◽  
Time Resolved ◽  
Mangrove Root ◽  
Mangrove Roots ◽  
A Chain ◽  
Complex Flow Structure

Abstract Mangrove roots produce complex flow structure interactions with their environment, which affect the nutrient, habitat and aquatic animals. Analysis of the flow structure behind the roots extends to a broad range of mangrove-inspired applications that provides understanding into complex flows encountered in unidirectional riverine flows. In this work, we modeled the mangrove roots with a cluster of rigid circular cylinders to investigate the vortex structure downstream of the models. The vortex organization of the patch of cylinder wakes was studied experimentally by time-resolved volumetric three-componential volumetric velocimetry (V3V) at Reynolds numbers 1014 and 3549. The results show that the vortex structure in the 3-D flow field reveals a regular shedding at Re = 1014, forming von Kármán vortices dominating the 3D motion. The flow structure behind rigid patches is coherent and the streamwise velocity remains unchanged. The regime for a flexible patch at Re = 3549 produces an intricate pattern where the multiple counter-rotating vortexes distorted substantially and forming a chain of rhombus-like vortex cells in the near wake. The information for the 3D flow feature provides useful information to a robust structure for Seawall erosion.

Exploring the advantages and limitations of sampling methods commonly used in research facilities for zebrafish health inspections

2019 ◽  
Vol 54 (4) ◽  
pp. 373-385 ◽  
Author(s):  
David Marancik ◽  
Jason Collins ◽  
Josephine Afema ◽  
Christian Lawrence
Keyword(s):  
Sample Size ◽  
Pathogen Detection ◽  
Sampling Methods ◽  
Diagnostic Testing ◽  
Scientific Integrity ◽  
Fish Health ◽  
Fish Welfare ◽  
Prevalence Level ◽  
Pathogen Prevalence ◽  
Research Facilities

Examining zebrafish populations for the presence of disease is an integral component of managing fish health in research facilities. Currently, many different strategies are used for zebrafish fish health inspections, which is a scenario that may result in subjective and biased diagnostic evaluations. The goal of this study was to compare the success of pathogen detection between a sample size of randomly selected fish ( n = 60) that provides 95% confidence in pathogen detection based on a presumed pathogen prevalence level ≥5%, and other subpopulations and sample numbers commonly submitted for diagnostic testing within a 1000 tank, 30,000 fish, recirculating research system. This included fish collected from a sump tank ( n = 53), sentinel fish ( n = 11), and fish that were found moribund or freshly dead ( n = 18). Additionally, five fish from each subpopulation were collected for histopathologic examination. A second study used retrospective data to examine pathogen distribution between systems ( n = 2−5) in multi-system facilities ( n = 5) using a sample size of 60 fish per system. For the pathogens detected, results supported the use of representative sample numbers rather than smaller numbers of populations considered more at risk. The exception to this is for the moribund/mortality group, which may be a resource for targeted surveillance of select pathogens. Each system within multi-system facilities should be considered separate units in terms of fish health inspections and biosecurity. Development of these evidence-based standards for fish health inspections in zebrafish systems enhances fish welfare, provides identification of potentially zoonotic pathogens, and ensures scientific integrity and reproducibility of research results.

Site specific assessments of burrow- and lentic-dwelling crayfish communities: A proposed sampling design

2015 ◽  
Vol 21 (1) ◽  
pp. 63-69
Author(s):  
Christopher A. Taylor ◽  
Bryan S. Engelbert ◽  
Robert J. DiStefano
Keyword(s):  
Sampling Design ◽  
Sampling Methods ◽  
Selection Process ◽  
Additional Time ◽  
Standing Water ◽  
Random Site ◽  
Total Community ◽  
Standing Waters ◽  
Floodplain Habitats ◽  
Capture Technique

Abstract We conducted a study to investigate methods to assess crayfish populations typically found in low gradient, lentic, floodplain habitats in Missouri. We used a random site selection process that allowed us to capture all known species from this region of Missouri. We compared two sampling methods for primary burrowing crayfishes at our sampling sites: hook-and-line capture technique and burrow excavation. Adjacent standing water habitats at sites were also sampled using a timed search method. Hook-and-line capture success was substantially less than reported in the literature (0.7% versus 80%), while burrow excavation was higher than reported (64% versus 40.7%). We successfully captured six crayfish species using burrow excavation, whereas lentic timed search sampling captured nine species in adjacent standing waters at our sampling sites. Our results suggest that additional efforts sampling lentic habitats rather than additional time searching for and excavating burrows is more likely to capture total community richness. We found a seasonal influence on burrow occupancy surveys, as Julian day was positively correlated to finding active crayfish burrows. Crayfish capture in standing water was positively affected by soil temperature, and negatively correlated to Julian day.

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