scholarly journals A performance comparison of sampling methods in the assessment of species composition patterns and environment–vegetation relationships in species-rich grasslands

2017 ◽  
Vol 86 (4) ◽  
Author(s):  
Grzegorz Swacha ◽  
Zoltán Botta-Dukát ◽  
Zygmunt Kącki ◽  
Daniel Pruchniewicz ◽  
Ludwik Żołnierz
Keyword(s):  
Species Composition ◽  
Sampling Method ◽  
Sampling Methods ◽  
Vegetation Type ◽  
Habitat Type ◽  
Spatial Arrangement ◽  
Performance Comparison ◽  
Systematic Sampling ◽  
Soil Parameters ◽  
Preferential Sampling

The influence that different sampling methods have on the results and the interpretation of vegetation analysis has been much debated, but little is yet known about how the spatial arrangement of samples affect patterns of species composition and environment–vegetation relationships within the same vegetation type. We compared three data sets of the same sample size obtained by three standard sampling methods: preferential, random, and systematic. These different sampling methods were applied to a study area comprising of 36 ha of intermittently wet <em>Molinia</em> meadows. We compared the performance of the three methods under two management categories: managed (extensively mown) and unmanaged (abandoned for 10 years). A total of 285 vegetation-plots were sampled, with 95 plots recorded per sampling method. In preferential sampling, we sampled only patches of vegetation with an abundance of indicator species of the habitat type, while random and systematic plots were positioned independently from the researcher by using GIS. The effect of each sampling method on the patterns of species composition and species–environment relationships was explored by redundancy analysis and the significance of effects was tested by the randomization test. Preferential sampling revealed different patterns of species composition than random and systematic sampling methods. Random and systematic sampling methods have resulted in broader vegetation variability than with preferential sampling method. Preferential sampling revealed different relationship between soil parameters and species composition in contrast to random and systematic sampling methods. Although we have not found significant differences in vegetation–environment relationships between random and systematic sampling methods, random sampling revealed a more robust correlation of species data to soil factors than preferential and systematic sampling methods. Intentional restriction of vegetation variation sampled preferentially may be detrimental to statistical inference in studies of species composition patterns and vegetation–environment relationships.

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.

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  Efficiency of adaptive cluster sampling and traditional sampling for coastal mangrove in Hainan of China

2012 ◽  
Vol 58 (No. 9) ◽  
pp. 381-390 ◽  
Author(s):  
Y. Lei ◽  
J. Shi ◽  
T. Zhao
Keyword(s):  
Sampling Method ◽  
Sampling Methods ◽  
Unit Area ◽  
Simple Random Sampling ◽  
Systematic Sampling ◽  
Cluster Sampling ◽  
Density Estimator ◽  
Adaptive Cluster Sampling ◽  
Initial Sample ◽  
Initial Sampling

Based on two species of Coastal Mangrove in Hainan of China, Sonneratia Apetala Buch-Ham and Sonneratia caseoli, we estimated the density of the two species to evaluate the efficiency of adaptive cluster sampling (ACS), simple random sampling (SRS) and traditional systematic sampling (SYS). Our initial experimental designs for ACS consisted of 5 unit areas, 6 initial sampling proportions, 4 initial sample sizes and 5 criterion values in 1,000&nbsp;repetitions. From the aspect of factors influencing efficiency, we analysed the efficiency of ACS in various designs. We also compared the efficiencies of the three methods on the indexes of the relative error, the variance of density estimator and the relative sampling efficiencies. We found that ACS yielded smaller variance than the traditional sampling methods. ACS was a powerful sampling method when a population was spatially aggregated. We also determined the optimum unit area for the two species studied using the two estimators (HT and HH) of adaptive cluster sampling. They were 20&nbsp;m<sup>2 </sup>(2 &times; 10 m), 15 m<sup>2 </sup>(3 &times; 5 m) for S. Apetala Buch-Ham and 25 m<sup>2 </sup>(5 &times; 5 m), 15 m<sup>2 </sup>(3 &times; 5 m) for S. caseolari, respectively.

scholarly journals Floristic composition, structure and soil-vegetation relations in three white-sand soil patches in central Amazonia

2018 ◽  
Vol 48 (1) ◽  
pp. 46-56 ◽  
Author(s):  
Layon Oreste DEMARCHI ◽  
Veridiana Vizoni SCUDELLER ◽  
Livia Carvalho MOURA ◽  
Randolpho Gonçalves DIAS-TERCEIRO ◽  
Aline LOPES ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Forest Structure ◽  
Vegetation Type ◽  
Structural Parameters ◽  
Floristic Composition ◽  
Soil Parameters ◽  
Similar Species ◽  
White Sand ◽  
Composition Structure

ABSTRACT The Amazonian white-sand vegetation presents a set of unique features, such as the dominance of a few species, high endemism and low species richness, which differentiate it from other Amazonian forests. Soil parameters have long been recognized as the main drivers of white-sand vegetation (WSV) characteristics. However, how they influence the composition, richness and structure of this vegetation type is still poorly understood. In this study we investigated the variation in floristic composition between patches and the soil-vegetation relations in three central Amazonian WSV patches. We tested whether slight differences in soil properties are linked with differences in floristic composition, species richness and forest structure in adjacent patches. In each patch three plots of 50 x 50 m were sampled (a total of 2.25 ha). Soil samples were collected for each plot. The sampling cutoff for arboreal individuals was DBH ≥ 5 cm. We sampled a total of 3956 individuals belonging to 40 families and 140 species. In each patch only a few species were dominant, but the dominant species varied among patches. Differences among patches were significant, but plots in the same patch tended to have similar species composition. The variable sum of bases (SB) was directly related to species composition, however, species richness and forest structure were not related to soil parameters. Even small variations in soil parameters can change species composition in WSV, although these variations do not necessarily influence the richness and other structural parameters.

scholarly journals An Improved Fuzzy Vector Signature with Reusability

2020 ◽  
Vol 10 (20) ◽  
pp. 7141
Author(s):  
Ilhwan Lim ◽  
Minhye Seo ◽  
Dong Hoon Lee ◽  
Jong Hwan Park
Keyword(s):  
Sampling Method ◽  
Performance Comparison ◽  
Error Rates ◽  
Efficiency Improvement ◽  
Fuzzy Extractor ◽  
Authentication Protocols ◽  
Biometric Data ◽  
Single User ◽  
Helper Data ◽  
Fuzzy Vector

Fuzzy vector signature (FVS) is a new primitive where a fuzzy (biometric) data w is used to generate a verification key (VKw), and, later, a distinct fuzzy (biometric) data w′ (as well as a message) is used to generate a signature (σw′). The primary feature of FVS is that the signature (σw′) can be verified under the verification key (VKw) only if w is close to w′ in a certain predefined distance. Recently, Seo et al. proposed an FVS scheme that was constructed (loosely) using a subset-based sampling method to reduce the size of helper data. However, their construction fails to provide the reusability property that requires that no adversary gains the information on fuzzy (biometric) data even if multiple verification keys and relevant signatures of a single user, which are all generated with correlated fuzzy (biometric) data, are exposed to the adversary. In this paper, we propose an improved FVS scheme which is proven to be reusable with respect to arbitrary correlated fuzzy (biometric) inputs. Our efficiency improvement is achieved by strictly applying the subset-based sampling method used before to build a fuzzy extractor by Canetti et al. and by slightly modifying the structure of the verification key. Our FVS scheme can still tolerate sub-linear error rates of input sources and also reduce the signing cost of a user by about half of the original FVS scheme. Finally, we present authentication protocols based on fuzzy extractor and FVS scheme and give performance comparison between them in terms of computation and transmission costs.

scholarly journals Do the assemblages of benthic macroinvertebrates in nearshore waters of Western Australia vary among habitat types, zones and seasons?

2005 ◽  
Vol 85 (2) ◽  
pp. 217-232 ◽  
Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell
Keyword(s):  
Species Composition ◽  
Benthic Macroinvertebrates ◽  
Habitat Type ◽  
Abundant Species ◽  
Subtidal Zone ◽  
Habitat Types ◽  
Environmental Characteristics ◽  
Deposit Feeding ◽  
Number Of Individuals

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.

scholarly journals New data on the ecological peculiarities and the distribution in Bulgaria of the vulnerable habitat F3.1d Balkan-Anatolian submontane genistoid scrub from the European Red List of Habitats

Hacquetia ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 271-287
Author(s):  
Georgi Kunev ◽  
Rossen Tzonev
Keyword(s):  
Vegetation Type ◽  
Volcanic Rocks ◽  
Habitat Type ◽  
Life Forms ◽  
Plant Life Forms ◽  
Area Of Occupancy ◽  
Floristic Elements ◽  
First Time ◽  
Floristic Structure ◽  
East Mediterranean Region

Abstract The study presents new data on the habitat dominated by the species complex of Genista lydia/G. rumelica in Bulgaria. It is based on 129 phytocoenological relevés and provides information on the chorology, ecology and floristic structure of these communities. This habitat type occupies substrates composed by different volcanic rocks. The floristic structure is very rich in species. The phytogeographical relationships with the East Mediterranean region are considerable, which is proved by the high occurrence of floristic elements with Mediterranean or sub-Mediterranean origin. The plant life-forms analysis demonstrates that the therophytes, geophytes and chamephytes prevail in their floristic structure, which is also typical for the shrub communities in this region. During the field study this vegetation type has been mapped and its total area of occupancy has been calculated. For a first time it is proposed this habitat to be divided into three habitat sub-types due to the established differences in the environmental factors. Some recommendations have been proposed on the conservation management and also complements on the habitat‘s descriptions in EUNIS habitat classification.

scholarly journals KONDISI WISATA MANGROVE DI DESA PASAR BANGGI, KABUPATEN REMBANG Mangrove Tourism Conditions in Pasar Banggi Village, Rembang Regency

2019 ◽  
Vol 8 (3) ◽  
pp. 221-225
Author(s):  
Danang Adi Saputro ◽  
Frida Purwanti ◽  
Siti Rudiyanti
Keyword(s):  
Species Composition ◽  
Mangrove Forest ◽  
Mangrove Ecosystem ◽  
Google Earth ◽  
Survey Method ◽  
Systematic Sampling ◽  
Sampling Techniques ◽  
Mangrove Species ◽  
Sampling Points ◽  
Exploratory Survey

ABSTRAK Mangrove merupakan tumbuhan yang hidup di daerah pasang surut sebagai ekosistem interface antara daratan dengan lautan. Ekosistem mangrove di desa Pasar Banggi Kabupaten Rembang merupakan perpaduan antara mangrove alami dan hasil rehabilitasi. Tujuan penelitian ini untuk mengetahui kondisi mangrove di Desa Pasar Banggi, Rembang dilihat dari  komposisi jenis, kerapatan dan ketebalan mangrove serta menganalisis tingkat kesesuaian wisata mangrove di Desa Pasar Banggi, Rembang. Metode yang digunakan adalah metode survey lapangan yang bersifat eksploratif, dimana  teknis pengumpulan data menggunakan sistematik sampling. Data yang diambil meliputi 5 variabel yaitu: jenis, kerapatan mangrove dan asosiasi biota (hasil pengamatan lapangan dan perbandingan dari penelitian terdahulu), ketebalan (citra Google Earth Oktober 2016), pasang surut (data BMKG Oktober 2016). Pengambilan sampel dilakukan pada 3 stasiun, dimana setiap stasiun terdapat 3 titik sampling. Komposisi jenis mangrove di desa Pasar Banggi terdapat 3 jenis mangrove yaitu Rhizopora stylosa, R. mucronata, dan R. Apiculata, dengan kerapatan mangrove tertinggi yaitu 62 ind/100m2 dan ketebalan mangrove tertinggi sepanjang 139 m. Kondisi hutan mangrove desa Pasar Banggi termasuk dalam kategori sesuai (S2) untuk kegiatan wisata berkelanjutan di Kabupaten Rembang. ABSTRACT Mangroves are plants that grow in a tidal areas an interface ecosystems between terrestrial and marine. Mangrove ecosystem in the Pasar Banggi Village,  Rembang Regency is a combination results of natural mangrove and rehabilitation. The purpose of this study were to determine condition of mangroves in the Pasar Banggi Village, Rembang, seen from the species composition, density and thickness of mangroves and to analyze the suitability level of mangrove tourism in the Pasar Banggi Village, Rembang. The method used in this study was an exploratory survey method, data collected using systematic sampling techniques. Mangrove tourism data collection was carried out of 5 variables, i.e.: type of mangrove, density of mangroves and associations of biota (from observations and comparisons of previous studies), thickness (Google Earth image October 2016), tides (data BMKG October 2016). Sampling was conducted at 3 stations, each station has 3 sampling points. The composition of mangrove species in Pasar Banggi village consists of 3 types of mangroves, namely Rhizopora stylosa, R. mucronata, and R. Apiculata, with the highest density of mangrove 62 ind / 100m2 and the highest thickness of mangrove along 139 m. The condition of mangrove forest in the Pasar Banggi village was included in the appropriate category (S2) for sustainable tourism activities in the Rembang Regency.

scholarly journals Komposisi Jenis Udang Air Tawar di Sungai Batambean, Pulau Labobo, Banggai Laut, Sulawesi Tengah, Indonesia

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Puji Rahayu ◽  
Annawaty Annawaty
Keyword(s):  
Environmental Factors ◽  
Species Composition ◽  
Sampling Method ◽  
Conservation Status ◽  
Freshwater Shrimp ◽  
Purposive Sampling ◽  
Freshwater Shrimps ◽  
The Family ◽  
Central Sulawesi ◽  
Abiotic Environmental Factors

Labobo isle is one of the satellite isle located around the mainland of Sulawesi Island. This study aims to determine the species composition of freshwater shrimp in the Batambean Stream located on Labobo Island, Banggai Laut, Central Sulawesi, Indonesia. A purposive sampling method based on the habitat of freshwater shrimps was applied to collect the shrimps. Measurement of abiotic environmental factors is carried out before samples collection. Furthermore, freshwater shrimp are collected using tray net and hand net. Collected specimens were preserved in alcohol 96%. The specimen wasidentified at the Laboratory of Animal Biosystematics and Evolution, Department of Biology, Faculty of Sciences, Tadulako University. The composition of freshwater shrimp species in the Batambean Stream consists of four species, namely Macrobrachium equidens, M. australe, and M. latidactylus and Caridina gracilipes. The first three species belong to the family Palaemonidae while the latter species is a member of the family Atyidae. The brief description and conservation status of each species  were also provided

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