Life-class stages in coast daisy-bush (Olearia axillaris: Asteraceae) as a possible means of monitoring coastal dunes

2005 ◽  
Vol 53 (2) ◽  
pp. 133 ◽  
Author(s):  
Julie Hinchliffe ◽  
John G. Conran
Keyword(s):  
Cluster Analysis ◽  
Population Structure ◽  
Rapid Assessment ◽  
South Australia ◽  
Coastal Dunes ◽  
Later Life ◽  
Main Trunk ◽  
Trunk Diameter ◽  
Coastal Foredunes

Olearia axillaris (DC.) F.Muell. ex Benth.: Asteraceae) shrubs in the remnant coastal foredunes at Tennyson in suburban Adelaide, South Australia, were measured for height, width, largest trunk diameter, percentage stem reflexing, percentage procumbent stems and percentage dead stems. Cluster analysis grouped the plants into three distinct life classes: Juvenile, with erect trunks <1 m tall and main trunk <5 cm in diameter; Mature, at ~1.5 m tall and with numerous reflexed stems 8–12 cm in diameter; and Senescent, at ~2 m tall, trunk 8–12 cm in diameter, with numerous procumbent stems and dead branches. A survey of the site also found that although abundant, indicating continuing recruitment, juveniles were most common on the foredunes. Application of this life-classing technique to several burnt and unburnt sites in the Coorong, South Australia, confirmed its utility for assessing population structure, with recently burnt sites showing significantly fewer specimens from later life classes. The ability to life class O. axillaris permits rapid assessment of population structure in this dominant coastal foredune shrub, allowing dune health and recruitment to be monitored easily and managed more efficiently.

Empirical Evaluation of Genetic Clustering Methods Using Multilocus Genotypes From 20 Chicken Breeds

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 699-713
Author(s):  
Noah A Rosenberg ◽  
Terry Burke ◽  
Kari Elo ◽  
Marcus W Feldman ◽  
Paul J Freidlin ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Population Structure ◽  
Clustering Algorithm ◽  
Empirical Evaluation ◽  
Unknown Origin ◽  
Clustering Methods ◽  
Genetic Cluster ◽  
Data Set ◽  
Multilocus Genotypes ◽  
Chicken Breeds

Abstract We tested the utility of genetic cluster analysis in ascertaining population structure of a large data set for which population structure was previously known. Each of 600 individuals representing 20 distinct chicken breeds was genotyped for 27 microsatellite loci, and individual multilocus genotypes were used to infer genetic clusters. Individuals from each breed were inferred to belong mostly to the same cluster. The clustering success rate, measuring the fraction of individuals that were properly inferred to belong to their correct breeds, was consistently ~98%. When markers of highest expected heterozygosity were used, genotypes that included at least 8–10 highly variable markers from among the 27 markers genotyped also achieved &gt;95% clustering success. When 12–15 highly variable markers and only 15–20 of the 30 individuals per breed were used, clustering success was at least 90%. We suggest that in species for which population structure is of interest, databases of multilocus genotypes at highly variable markers should be compiled. These genotypes could then be used as training samples for genetic cluster analysis and to facilitate assignments of individuals of unknown origin to populations. The clustering algorithm has potential applications in defining the within-species genetic units that are useful in problems of conservation.

scholarly journals The role and importance of value-based segmentation on the cohort of millennials: Case study Serbia

Marketing ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 43-57
Author(s):  
Tatjana Mamula-Nikolić ◽  
Nenad Perić ◽  
Stefan Alimpić
Keyword(s):  
Cluster Analysis ◽  
Factor Analysis ◽  
Population Structure ◽  
Generation Y ◽  
National Sample ◽  
Urban Rural ◽  
Research Findings ◽  
The Subject ◽  
Representative National Sample

The paper deals with the value-based segmentation conducted on Millennials generation in Serbia. It presents the research findings of the five segments of the Serbian Millennials according to their values and life style. The subject of defining the set of segments was processed by conducting a cluster and factor analysis on the representative national sample of Millennials in Serbia. Once the cluster analysis discovered the segments, the next step was to understand the essence of the clusters or segments. The sample is consisted of 1000 respondents, reflecting the population structure of the Serbian generation Y according to gender, age, region and type of settlement (urban / rural). The analysis showed some quite interesting and in some parts contradictory results. The results of this survey are relevant for sociologists, strategists, communications professionals and managers who are interested in this generation of voters, consumers, employees, leaders and entrepreneurs.

scholarly journals Lateral vegetation growth rates exert control on coastal foredune hummockiness and coalescing time

2017 ◽  
Vol 5 (3) ◽  
pp. 417-427 ◽  
Author(s):  
Evan B. Goldstein ◽  
Laura J. Moore ◽  
Orencio Durán Vinent
Keyword(s):  
Growth Rates ◽  
Coastal Dunes ◽  
High Water ◽  
Lateral Direction ◽  
Plant Dispersal ◽  
Vegetation Growth ◽  
The Us ◽  
Two Parameters ◽  
Coastal Foredunes ◽  
Conceptual Work

Abstract. Coastal foredunes form along sandy, low-sloped coastlines and range in shape from continuous dune ridges to hummocky features, which are characterized by alongshore-variable dune crest elevations. Initially scattered dune-building plants and species that grow slowly in the lateral direction have been implicated as a cause of foredune hummockiness. Our goal in this work is to explore how the initial configuration of vegetation and vegetation growth characteristics control the development of hummocky coastal dunes including the maximum hummockiness of a given dune field. We find that given sufficient time and absent external forcing, hummocky foredunes coalesce to form continuous dune ridges. Model results yield a predictive rule for the timescale of coalescing and the height of the coalesced dune that depends on initial plant dispersal and two parameters that control the lateral and vertical growth of vegetation, respectively. Our findings agree with previous observational and conceptual work – whether or not hummockiness will be maintained depends on the timescale of coalescing relative to the recurrence interval of high-water events that reset dune building in low areas between hummocks. Additionally, our model reproduces the observed tendency for foredunes to be hummocky along the southeast coast of the US where lateral vegetation growth rates are slower and thus coalescing times are likely longer.

A molecular systematic overview of wolf spiders associated with Great Artesian Basin springs in South Australia: evolutionary affinities and an assessment of metapopulation structure in two species

2008 ◽  
Vol 22 (2) ◽  
pp. 151 ◽  
Author(s):  
Travis B. Gotch ◽  
Mark Adams ◽  
Nick P. Murphy ◽  
Andrew D. Austin
Keyword(s):  
Population Structure ◽  
South Australia ◽  
Species Boundaries ◽  
Molecular Systematic ◽  
Wolf Spiders ◽  
Widespread Species ◽  
Artesian Basin ◽  
Polymorphic Loci ◽  
Great Artesian Basin ◽  
Allozyme Loci

The molecular genetic techniques of allozyme electrophoresis and mitochondrial DNA sequencing were used to examine species boundaries, phylogenetic affinities, and population structure in wolf spiders associated with artesian springs of the Great Artesian Basin (GAB) in South Australia. These springs contain the only permanent water in this extremely arid region, and consequently are of great biological, economic, and sociological significance. Molecular diagnoses of species boundaries in nine lycosid species, involving 56 individuals genotyped at 37 putative allozyme loci and 21 individuals sequenced for a ~600-bp portion of nicotinamide adenine dinucleotide dehydrogenase 1 (NADH1), were largely concordant with those recently proposed on morphological criteria. They also identified a species not previously collected, and suggested that GAB and mesic forms of Venatrix arenaris (Hogg) may not be conspecific. As well as insights into the evolutionary relationships among species and genera, phylogenetic analysis demonstrated two distinct GAB lineages within Venatrix Roewer and Hogna Simon. Population structure analyses of the two most widespread species revealed contrasting patterns. For V. fontis Framenau & Vink, allozyme analyses of 300 individuals at 15 polymorphic loci plus NADH1 sequence analysis of 72 individuals revealed the presence of distinctive subpopulations at most sites, and a partial correlation with overall geographic proximity. In contrast, allozyme analysis of 191 V. arenaris specimens at 12 polymorphic loci demonstrated a comparative lack of both within-site variability and between-site differentiation in the GAB metapopulation.

Population structure and genetic diversity of the black-footed rock-wallaby (Petrogale lateralis MacDonnell Ranges race)

2015 ◽  
Vol 63 (2) ◽  
pp. 91 ◽  
Author(s):  
Laura Ruykys ◽  
Melanie L. Lancaster
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Arid Zone ◽  
South Australia ◽  
Ex Situ ◽  
Population Substructure ◽  
Suitable Habitat ◽  
Critical Determinant ◽  
Population Structuring ◽  
Recovery Program

Genetic diversity is a critical determinant of the persistence of populations because it enables animals to evolve and adapt to environmental change. Black-footed rock-wallabies (Petrogale lateralis MacDonnell Ranges race), or warru, once occupied virtually all suitable habitat within the arid zone of central Australia. However, only two metapopulations now remain in the southern portion of this race’s range (South Australia) and a recovery program has involved both in- and ex-situ conservation initiatives. To establish whether genetic factors such as inbreeding may be inhibiting population recovery, the current study examined the population structure and genetic diversity of animals in the three largest-known extant colonies using six polymorphic microsatellite loci. Bayesian and frequency-based assignment tests revealed substantial population structuring (pairwise FST values 0.122–0.278), congruent with geographically distinct colonies. There was some evidence of dispersal, with two migrants identified across two colonies, but little evidence for extensive interbreeding among colonies. Population substructure was evidenced by high values of FIS in one colony. All populations possessed relatively high levels of genetic diversity (allelic richness: 5.1–7.5, heterozygosity: 0.70–0.72). On the basis of a genetic analysis of parentage, approximately half of all males and females in the known metapopulations produced offspring. This has likely contributed to the retention of genetic diversity across colonies. These findings have implications for the management of both the in- and ex-situ warru populations.

scholarly journals Ocean-wide genomic variation in Gray's beaked whales, Mesoplodon grayi

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
M. V. Westbury ◽  
K. F. Thompson ◽  
M. Louis ◽  
A. A. Cabrera ◽  
M. Skovrind ◽  
...  
Keyword(s):  
Population Structure ◽  
Demographic History ◽  
South Australia ◽  
Population Connectivity ◽  
Genomic Variation ◽  
Suitable Habitat ◽  
Effective Population ◽  
Beaked Whales ◽  
Marine Megafauna ◽  
Demographic Patterns

The deep oceans of the Southern Hemisphere are home to several elusive and poorly studied marine megafauna. In the absence of robust observational data for these species, genetic data can aid inferences on population connectivity, demography and ecology. A previous investigation of genetic diversity and population structure in Gray's beaked whale ( Mesoplodon grayi ) from Western Australia and New Zealand found high levels of mtDNA diversity, no geographic structure and stable demographic history. To further investigate phylogeographic and demographic patterns across their range, we generated complete mitochondrial and partial nuclear genomes of 16 of the individuals previously analysed and included additional samples from South Africa ( n = 2) and South Australia ( n = 4), greatly expanding the spatial range of genomic data for the species. Gray's beaked whales are highly elusive and rarely observed, and our data represents a unique and geographically broad dataset. We find relatively high levels of diversity in the mitochondrial genome, despite an absence of population structure at the mitochondrial and nuclear level. Demographic analyses suggest these whales existed at stable levels over at least the past 1.1 million years, with an approximately twofold increase in female effective population size approximately 250 thousand years ago, coinciding with a period of increased Southern Ocean productivity, sea surface temperature and a potential expansion of suitable habitat. Our results suggest that Gray's beaked whales are likely to be resilient to near-future ecosystem changes, facilitating their conservation. Our study demonstrates the utility of low-effort shotgun sequencing in providing ecological information on highly elusive species.

scholarly journals A Rapid Assessment Technique to Assist Management of the White Shark (Carcharodon Carcharias) Cage Dive Industry, South Australia

2013 ◽  
Vol 6 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Russell Bradford ◽  
Rachel Robbins
Keyword(s):  
Rapid Assessment ◽  
Economic Value ◽  
South Australia ◽  
White Shark ◽  
Rapid Expansion ◽  
Conservative Estimate ◽  
Participation Rates ◽  
Carcharodon Carcharias ◽  
Assessment Technique ◽  
The Future

Port Lincoln, South Australia is the departure port for the only white shark, Carcharodon carcharias, cage dive industry in Australia. Established in the early 1960’s as a niche tourism venture, the industry has recently undergone a rapid expansion to accommodate greater passenger numbers, more tourism operators, and additional infrastructure aimed at capturing a greater proportion of the tourist dollar. However, to date, there has been no assessment of growth in the industry. We have used the operator logbook system, introduced in 2000, as the basis for a rapid assessment of the maturity as well as a conservative estimate of the economic value of the industry, with a focus on 2011. From the logbook system the number of days on-site has increased from an average of 67 days per year prior to 2007 to 287 days on-site in 2011. In 2011 the industry accommodated approximately 5200 passengers with a direct domestic expenditure estimated to be in excess of 6 million AUD. Changes in shark behaviour have been observed following the increase in days on-site. The white shark cage dive industry has reached a stage in its development where increased management is required in order to ensure a viable industry into the future. The rapid assessment technique described herein will allow managers to track changes in cage dive participation rates and quickly respond to changes in the industry.

scholarly journals Genetic Diversity and Population Structure of Job’s Tears(Coix lacryma-jobi L.) Germplasm Based on ISSR Marker

2021 ◽  
Author(s):  
Gang Shen ◽  
Lingling Yang ◽  
Teerayoot Girdthai ◽  
Fanzhi Liu ◽  
Yuhua Fu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Population Structure ◽  
Genetic Distance ◽  
Genetic Relationship ◽  
Germplasm Collection ◽  
Issr Markers ◽  
Issr Primer ◽  
Upgma Cluster ◽  
Job’S Tears

Abstract Background: Job's tears（Coix lachryma-jobi L.）is a minor cereal and an important food item in some parts of Asia. It has also been used in the traditional Chinese medicine for relieving various ailments, therefore, it plays an important role in our lives. Lack of excellent new varieties hinders the development of coix as a sustainable crop, and it is urgent to provide new cultivars with excellent trait in Chinese Coix industry. Results: ISSR markers were used to assess the genetic diversity and population structure of 8 populations of Job’s tears in China. A genotyping analysis that utilized ten ISSR primer pairs resulted in the production of 116 bands, of which 98 were polymorphic. The Guizhou population (PPB = 81.90%, h = 0.3113, I = 0.4589) was the most genetically diverse, while the lowest was observed in the Hebei population (PPB = 46.55%, h = 0.1842, I = 0.2701). Genetic differentiation analyses including GST and AMOVA illustrated that genetic variation was most prevalent within populations while only minor variations were observed among populations. Genetic distance coefficients ranged from 0.0095 to 0.0948 for the 8 populations; the genetic relationship between the Guizhou and Chongqing populations was the closest, while the most distant genetic relationship occurred between the Hubei and Hunan populations. The results of an UPGMA cluster analysis that investigated genetic diversity among the populations were consistent with the genetic distance results. The results of a STRUCTURE analysis suggested that 94 Job’s tears accessions could be grouped into two subpopulations. Moreover, according to a cluster analysis based on the UPGMA for individuals of Job’s tears, accessions were divided into two major clusters. The results of the Bayesian cluster and UPGMA cluster analyses were largely consistent despite minor differences. There was no significant correlation between genetic distance and geographic distance (r = 0.055, p = 0.782). Conclusions: Our study was undertaken to systematically analyze genetic diversity and population structure in 94 Job’s tears accessions using ISSR markers. And this study provides us with valuable information pertaining to germplasm collection, genetic improvement, and systematic utilization of Job’s tears.

scholarly journals A proposal for tsunami mitigation by using coastal vegetations

2013 ◽  
Vol 3 ◽  
pp. 85-95
Author(s):  
Djati Mardiatno
Keyword(s):  
Avicennia Marina ◽  
Research Area ◽  
Anacardium Occidentale ◽  
Coastal Vegetation ◽  
Survey Method ◽  
Main Trunk ◽  
Coastal Morphology ◽  
Trunk Diameter ◽  
Density Correlation ◽  
Tsunami Mitigation

This research was conducted at the southern coastal area of central Java Island, Indonesia. It is aimed to identify several coastal vegetation characteristics for development of guideline for planning and design of tsunami mitigation. Survey method was applied to observe common coastal vegetation in the research area. Data collected from the survey consisted of vegetation parameters and coastal morphology. All selected vegetations were analyzed for their allometry relation of each species, maximum density, correlation between breaking moment and trunk diameter of each tree species, and correlation between trunk diameter and spacing between trees for each species. For coastal morphology, it was focused on topography and elevation from sea level. The results show that trees with the hard wood will be stronger to hold the pull moment on the main trunk. Younger trees with smaller diameter tend to be more flexible, thus they will unbreakable during the test. The other trees which have flexible trunk such as Terminalia catappa and Anacardium occidentale were often pulled out their roots than broken on their trunks. To obtain more extensive characteristic, it is necessary to carry out advanced measurements, especially on the older trees which have more than 10 cm diameter. Coastal areas consist of mud and sand materials tend to have a high tsunami risk, although mitigation treatments were different for both types. At the muddy area, the recommended vegetation are Avicennia marina and Rhizophora mucronata, meanwhile Casuarina equisetifolia and Anacardium occidentale, due to their high flexibility, will be more suitable on the sandy coast. Both types should be planted parallel to the shoreline. Casuarina is planted in the frontline followed by Anacardium behind it.

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