scholarly journals Comparison ofT-Square, Point Centered Quarter, andN-Tree Sampling Methods inPittosporum undulatumInvaded Woodlands

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Lurdes Borges Silva ◽  
Mário Alves ◽  
Rui Bento Elias ◽  
Luís Silva
Keyword(s):  
Sampling Design ◽  
Sampling Methods ◽  
Distribution Patterns ◽  
Tree Density ◽  
Parameter Estimates ◽  
Sampling Point ◽  
Density Range ◽  
Biomass Valorization ◽  
Precise Method ◽  
Tree Distribution

Tree density is an important parameter affecting ecosystems functions and management decisions, while tree distribution patterns affect sampling design.Pittosporum undulatumstands in the Azores are being targeted with a biomass valorization program, for which efficient tree density estimators are required. We comparedT-Square sampling, Point Centered Quarter Method (PCQM), andN-tree sampling with benchmark quadrat (QD) sampling in six 900 m2plots established atP. undulatumstands in São Miguel Island. A total of 15 estimators were tested using a data resampling approach. The estimated density range (344–5056 trees/ha) was found to agree with previous studies using PCQM only. Although with a tendency to underestimate tree density (in comparison with QD), overall,T-Square sampling appeared to be the most accurate and precise method, followed by PCQM. Tree distribution pattern was found to be slightly aggregated in 4 of the 6 stands. Considering (1) the low level of bias and high precision, (2) the consistency among three estimators, (3) the possibility of use with aggregated patterns, and (4) the possibility of obtaining a larger number of independent tree parameter estimates, we recommend the use ofT-Square sampling inP. undulatumstands within the framework of a biomass valorization program.

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.

Adaptive and Network Sampling for Inference and Interventions in Changing Populations

2017 ◽  
Vol 5 (1) ◽  
pp. 1-21
Author(s):  
Steven K Thompson
Keyword(s):  
Bayesian Methods ◽  
Fast Moving ◽  
Sampling Design ◽  
Sampling Methods ◽  
Intervention Programs ◽  
Time Averaging ◽  
Temporal Network ◽  
Network Sampling ◽  
Spatial Sampling Design ◽  
Over Time

Abstract In this paper, I discuss some of the wider uses of adaptive and network sampling designs. Three uses of sampling designs are to select units from a population to make inferences about population values, to select units to use in an experiment, and to distribute interventions to benefit a population. The most useful approaches for inference from adaptively selected samples are design-based methods and Bayesian methods. Adaptive link-tracing network sampling methods are important for sampling populations that are otherwise hard to reach. Sampling in changing populations involves temporal network or spatial sampling design processes with units selected both into and out of the sample over time. Averaging or smoothing fast-moving versions of these designs provides simple estimates of network-related characteristics. The effectiveness of intervention programs to benefit populations depends a great deal on the sampling and assignment designs used in spreading the intervention.

scholarly journals Fish assemblages along the coasts of Tunisia: a baseline study to assess the effectiveness of future Marine Protected Areas

2018 ◽  
Vol 19 (1) ◽  
pp. 11
Author(s):  
EMNA BEN LAMINE ◽  
PAOLO GUIDETTI ◽  
MOHAMED SALAH ROMDHANE ◽  
PATRICE FRANCOUR
Keyword(s):  
Sampling Design ◽  
Fish Assemblages ◽  
Distribution Patterns ◽  
Underwater Visual Census ◽  
Protection Measures ◽  
Coastal Fish ◽  
Significant Difference ◽  
The Status ◽  
Total Fish ◽  
Density And Biomass

The present study investigated coastal fish assemblages, using Underwater Visual Census (UVC) transects, in Tunisia (south Mediterranean basin). The rationale behind this work is to get i) a suggestive evidence about the status of fish assemblages, and ii) baseline data at 3 locations in Tunisia where 3 MPAs will be established, before the implementation of protection measures. At each location, we used a sampling design where fish censuses were performed in two types of zone: zones that will be inside MPAs, and zones that will remain outside. On the whole, 49 taxa belonging to 19 families were censused. Data reveal clear symptoms of overfishing, especially in terms of dominance of small- and medium-sized individuals of commercially relevant species. Our analyses, moreover, did not show any significant difference in whole fish assemblage structures (considering both density and biomass), patterns of average species richness, total fish density and biomass, density and biomass of different trophic categories of fishes, size distribution of commercially relevant species, between future-protected and unprotected zones. Overall, results suggest that 1) current fish assemblages at the three studied locations are likely to be seriously impacted by fishing activities, and 2) these data could be used as reliable baselines to assess the effectiveness of protection measures within the MPAs that will be established in the future. Our study is the first in Tunisia, and in North African coasts, that assessed distribution patterns of coastal fish assemblages by means of UVC, using a formal spatially replicated sampling design for resource management.

scholarly journals Gastropods In Mangrove Forest Of Tongkeina Village, Bunaken Sub-District, City Of Manado

2019 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Dewanti Y Talumingan ◽  
Ferdinand F. Tilaar ◽  
Jety K. Rangan ◽  
Maartinus M Baroleh ◽  
Victor N. R. Watung ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Mangrove Forest ◽  
Distribution Patterns ◽  
Common Species ◽  
Line Transect ◽  
Sampling Point ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Long Line ◽  
Made In

This research aims to determine the types or species of gastropod and its distribution in mangrove forests in Tongkeina village and to know the species of mangrove in Tongkeina village. The Research was conducted on one sampling point with one 100 meters long line transect which was is laid perpendicular to the outer direction of the mangrove.  To collect gastropod samples, three quadrates with a size of 10x10meters with a distance between the quadrate 5 meters were made. In the quadrate, 15 subquadrates sized 1x1meters were also made. Based on the results, there were 6 species of gastropods and two distribution patterns of i.e., Cluster the species of the Littoraria scabra, Angustassiminea castanea, Terebralia sulcate. The uniform distribution pattern is Ischinocerithium rostratum, Caliostoma jujubinum, and Nerita senegalensis. There are ten mangrove species found and  the most common species is Soneratia alba with a total of 27 individuals.Keywords: Gastropods, forest, Mangrove, Tongkeina village ABSTRAKPenelitian ini bertujuan untuk mengetahui Jenis-jenis gastropoda serta persebaran pada hutan mangrove di Kelurahan Tongkeina dan untuk mengetahui Jenis-jenis mangrove di Kelurahan Tongkeina. Penelitian hanya di lakukan satu titik pengambilan sampel dimana dibuat 1 line transek dengan Panjang 100meter yang di tarik tegak lurus dari arah terluar mangrove kemudian dibuat 3 kuadrat dengan ukuran 10x10meter dengan jarak antara kuadrat 5 meter, dan di dalam kuadrat dibuat 15 subkuadrat berukuran 1x1 meter. Berdasarkan penelitian hasil ditemukan ada 6 spesies gastopoda dan dua pola persebaran Gastropoda yaitu mengelompok dan seragam, spesies mengelompok yaitu Littoraria scabra, Angustassiminea castanea, Terebralia sulcate. Pola persebaran seragam yaitu Ischinocerithium rostratum, Caliostoma jujubinum, Nerita senegalensis. Mangrove ditemukan 10 Spesies yang terbanyak adalah Soneratia alba dengan jumlah 27 individu.Kata kunci: Gastropoda, Hutan, Mangrove, Kelurahan Tongkeina.

scholarly journals KARAKTER DAN SEBARAN DUKUH DI KECAMATAN KARANG INTAN DAN PENGARON

2021 ◽  
Vol 4 (3) ◽  
pp. 452
Author(s):  
Khairunisa Khairunisa ◽  
Ahmad Jauhari ◽  
Hafiziannor Hafiziannor
Keyword(s):  
Random Sampling ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Sampling Methods ◽  
Sampling Point ◽  
Land Utilization ◽  
Average Income ◽  
Purposive Sampling ◽  
Index Analysis ◽  
Well Data

Banjar Regency-South Kalimantan is found in the land utilization system by implementing a Dukuh (Fruit orchard) system including Karang Intan Sub-district and Archion. This system has a considerable influence on the environment and public income. But the data on the character and distribution of the Dukuh has not been well-data, therefore carried out the research of character and distribution of Dukuh in the district of Karang Intan and archion. The purpose of this research is to know the distribution and character of the Dukuh. The methods used in the research are NDVI analysis (Normalized Difference Vegetation Index), analysis of interchanges, random sampling points, and interviews with the community by purposive sampling methods. Based on the results of the analysis obtained the number of Dukuh in the district of Coral Diamond as much as 7,086 and District Archion 12,092. In The Sub-district of Karang Intan and the archion has 12 kinds of fruit Dengan and 11 kinds of fauna diversity in it and average income management Dukuh ranging from Rp.3.000.000 to Rp.5.000.000.Kabupaten Banjar-Kalimantan Selatan banyak ditemui sistem pemanfaatan lahan dengan menerapkan sistem dukuh (kebun buah) diantaranya Kecamatan Karang Intan dan Pengaron. Sistem ini memberikan pengaruh cukup besar terhadap lingkungan dan pendapatan masyarakat. Namun data mengenai karakter dan sebaran dukuh belum terdata dengan baik, maka dari itu dilakukan penelitian Karakter dan Sebaran dukuh di Kecamatan Karang Intan dan Pengaron. Tujuan dari penelitian ini untuk mengetahui persebaran dan karakter dari dukuh. Metode yang digunakan dalam penelitian adalah Analisis NDVI (Normalized Difference Vegetation Index), Analisis tumpang susun, random sampling point, dan wawancara dengan masyarakat dengan metode purposive sampling. Berdasarkan hasil analisis didapatkan jumlah persebaran dukuh dikecamatan karang intan sebanyak 7.086 dan kecamatan pengaron 12.092. Pada kecamatan Karang Intan dan Pengaron memiliki 12 macam jenis buah dengan 11 macam keanekaragaman fauna didalamnya dan penghasilan rata-rata pengelola dukuh berkisar Rp.3.000.000 sampai dengan Rp.5.000.000

scholarly journals Retention of tree-related microhabitats is more dependent on selection of habitat trees than their spatial distribution

2020 ◽  
Vol 139 (6) ◽  
pp. 1015-1028 ◽  
Author(s):  
Thomas Asbeck ◽  
Christian Messier ◽  
Jürgen Bauhus
Keyword(s):  
Spatial Distribution ◽  
Convex Hull ◽  
Distribution Patterns ◽  
Managed Forests ◽  
Tree Distribution ◽  
Reference Selection ◽  
Tree Retention ◽  
Evans Index ◽  
The Difference ◽  
Selection Of

Abstract Habitat trees, which provide roosting, foraging and nesting for multiple taxa, are retained in managed forests to support biodiversity conservation. To what extent their spatial distribution influences provisioning of habitats has rarely been addressed. In this study, we investigated whether abundance and richness of tree-related microhabitats (TreMs) differ between habitat trees in clumped and dispersed distributions and whether the abundance of fifteen groups of TreMs is related to tree distribution patterns. To identify habitat trees, we quantified TreMs in temperate mountain forests of Germany. We determined clumping (the Clark–Evans index), size of the convex hull, diameter at breast height, as well as altitude, slope and aspect of sites for their possible influence on TreMs. We additionally determined the difference in TreM abundance and richness among four options of selecting five habitat trees per ha from 15 candidates: (a) the most clumped trees, (b) five randomly selected and dispersed trees, (c) the single tree with highest abundance or richness of TreMs and its four closest neighbors and (d) a “reference selection” of five trees with known highest abundance or richness of TreMs irrespective of their distribution. The degree of clumping and the size of the convex hull influenced neither the abundance nor richness of TreMs. The reference selection, option (d), contained more than twice the number of TreMs compared to the most clumped, (a), or random distributions, (b), of five habitat trees, while option (c) assumed an intermediate position. If the goal of habitat tree retention is to maximize stand-level abundance and richness of TreMs, then it is clearly more important to select habitat trees irrespective of their spatial pattern.

Improved sampling of wildlife populations using airborne surveys

2002 ◽  
Vol 29 (3) ◽  
pp. 269 ◽  
Author(s):  
W. M. Khaemba ◽  
A. Stein
Keyword(s):  
Adaptive Sampling ◽  
Sampling Design ◽  
Adaptive Design ◽  
Sampling Error ◽  
Simple Random Sampling ◽  
Parameter Estimates ◽  
Systematic Design ◽  
The Common ◽  
Wildlife Populations ◽  
Connochaetes Taurinus

Parameter estimates, obtained from airborne surveys of wildlife populations, often have large bias and large standard errors. Sampling error is one of the major causes of this imprecision and the occurrence of many animals in herds violates the common assumptions in traditional sampling designs like systematic or simple random sampling even when stratification is used. In this paper, we present an adaptive sampling design that uses criteria of observed animal counts to maximise sample information and that is independent of the usual assumption of a uniform distribution for wildlife populations. For illustration, the design is applied to data derived from a survey carried out in the Masai Mara ecosystem (Mara) of Kenya, with a focus on three species: elephant (Loxodonta africana), kongoni (Alcelaphus buselaphus) and wildebeest (Connochaetes taurinus). The sampling design's more efficient estimates show an improvement on those from conventional systematic design, with a greater than 10 times reduction in estimated bias and a 37% lowering of the standard error. The adaptive design, however, underestimates population totals for species in large herds, while a multivariate extension gives only marginal improvements.

scholarly journals Use of camera-traps in natural trails and shelters for the mammalian survey in the Atlantic Forest

2012 ◽  
Vol 102 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Geruza L. Melo ◽  
Jonas Sponchiado ◽  
Nilton C. Cáceres
Keyword(s):  
Species Composition ◽  
Atlantic Forest ◽  
Sampling Design ◽  
Sampling Methods ◽  
Survey Methods ◽  
Sampling Strategy ◽  
Camera Traps ◽  
Sampling Effort ◽  
Forest Park ◽  
Forest Sites

In order to evaluate the efficiency of different mammalian survey methods, we compared traditional sampling techniques (use of camera-traps on roads and artificial trails, track censuses, and direct field visualization) with an alternative sampling design (camera-traps positioned in natural areas such as natural trails and shelters). We conducted the study in a deciduous Atlantic-Forest park in southern Brazil, and additionally compared our results with a previous intensive study carried out in the same area. Our considerably smaller sampling effort (example: 336 trap.day for our camera-traps versus 2,154 trap.day for the earlier study) registered the presence of 85% of the local known species, with camera-traps being 68% efficient. Moreover, shelter camera-traps revealed a different species composition regarding most of other sampling methods. This sampling strategy involving natural forest sites was therefore able to effectively optimize the chances of evaluating species composition in a shorter period, especially with respect to lower-density and cryptic species, as well as to detect species that avoid open, disturbed sites such as roads and man-made forest trails.

Distribution and Evolution of Bacteria on Lamb Carcasses During Aerobic Storage

1991 ◽  
Vol 54 (12) ◽  
pp. 945-949 ◽  
Author(s):  
MIGUEL PRIETO ◽  
MARÍA L. GARCÍA ◽  
MARÍA R. GARCÍA ◽  
ANDRÉS OTERO ◽  
BENITO MORENO
Keyword(s):  
Sampling Methods ◽  
Sampling Site ◽  
Storage Life ◽  
Sampling Point ◽  
Bacterial Counts ◽  
Mean Values ◽  
Ph Values ◽  
The Mean

The change of bacterial counts during storage life of chilled (3±1°C) lamb carcasses was determined by sampling at 0, 5, 10, and 15 d postslaughter and at the spoilage time. Three sites (neck, brisket, and leg) of each carcass were sampled using three sampling methods (swabbing, scraping, and excision of the swabbed and scraped areas). After slaughter, mean count of mesophiles (30°C) was 4.96 log10 CFU/cm2. The initial mean count of psychrotrophs (7°C) expressed as a percentage of the mean count of mesophiles was 33.4%. The mean values of mesophiles and psychrotrophs associated with spoilage were 7.4 log10/cm2 and 7.95 log10/cm2, respectively. Carcasses always had pH values above 5.8 and kept unspoiled 23–29 d. Brisket and leg were the most contaminated areas. Percentages of bacteria recovered by scraping were higher than those obtained by swabbing (ca. 20%). Bacterial counts were significantly affected by day of storage (p<0.001), sampling point (p<0.001), and temperature of incubation (p<0.05). Interaction between sampling day and sampling site was also observed.

Sign in / Sign up

Export Citation Format

Share Document