Genetic and Ecological Variation in Atherosperma moschatum and the Implications for Conservation of Its Biodiversity

1994 ◽  
Vol 42 (6) ◽  
pp. 663 ◽  
Author(s):  
A Shapcott
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
New South ◽  
Genetic Distances ◽  
Isolated Populations ◽  
Canopy Tree ◽  
South Wales ◽  
Genetic Substructure ◽  
Temperate Rainforests ◽  
Vegetative Spread

Population genetics and ecology of Atherosperma moschatum Labill. (sassafras), a major canopy tree of Australian temperate rainforests, were examined and used to identify priorities and strategies for conservation of its genetic diversity. The genetic diversity among populations was fairly low, but higher than average for long-lived late successional or wind dispersed species (Hamrick and Godt 1989). Genetic distances between populations were correlated with geographic distances and climatic differences. The major genetic differentiation was between the mainland populations and those in Tasmania, with the New South Wales populations being quite genetically distinct. Most genetic variation was found within populations, however, most populations were inbred. This is likely to be due to selfing and spatial genetic substructure resulting from vegetative spread and local dispersal. There was evidence of regeneration in all populations, however no consistent regeneration patterns emerged. Population density was inexplicably correlated with genetic distance. There was as much diversity in all variables (ecological and genetic) measured in small isolated populations as there was in stands within larger assemblages; therefore, population size does not appear to be a major factor affecting viability. Genetic variation was spread throughout the distribution of A. moschatum. Therefore, populations from throughout its range would need to be conserved to retain the genetic diversity within this species.

Patterns of Genetic Diversity and Nature of the Breeding System in Melaleuca alternifolia (Myrtaceae)

1992 ◽  
Vol 40 (3) ◽  
pp. 365 ◽  
Author(s):  
PA Butcher ◽  
JC Bell ◽  
GF Moran
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Distance Measures ◽  
Melaleuca Alternifolia ◽  
Isolated Populations ◽  
Tea Tree ◽  
South Wales ◽  
Baseline Information ◽  
Geographic Separation ◽  
Natural Stands

Melaleuca alternifolia (Maiden & Betche) Cheel is harvested from natural stands and plantations for production of Australian tea-tree oil. Genetic variation was examined and outcrossing rates estimated to provide baseline information for breeding and selection programs. The overall genetic diversity (HT = 0.186) is comparable to other regionally distributed Australian tree species. There was a general trend for more isolated populations to have less genetic variation than populations from the centre of the species distribution. The level of differentiation among populations was low (12%), associated with a high outcrossing rate (93%) and high levels of gene flow. Geographic separation of Queensland and New South Wales populations corresponds with genetic distance measures.

scholarly journals Genetic analysis of silver-fir populations in the Beskids

2011 ◽  
Vol 72 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Leon Mejnartowicz
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Abies Alba ◽  
Genetic Distances ◽  
Silver Fir ◽  
Geographical Distance ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Rare Alleles

Twenty-eight isozymic loci were studied in the Beskid Mts., in four populations of common silver-fir (<em>Abies alba</em>): one in Beskid Makowski (BM) and three populations in Beskid Sądecki (BS). Their genetic variation and diversity were analyzed, and Nei's genetic distances between the populations were calculated. The results show that the geographical distance between the BM population and the three BS populations is reflected in genetic distances. The BM population is clearly distinct from the others. It has the lowest genetic diversity (<em>I</em> = <em>0.42</em>), percentage of polymorphic loci <em>(%PoL </em>= <em>64.29</em>) and number of rare alleles (<em>NoRa </em>= <em>5</em>). Besides, the BM population has the highest observed heterozygosity (<em>Ho </em>= <em>0.291</em>), which exceeds the expected heterozygosity (<em>He </em>= <em>0.254</em>), estimated on the basis of the Hardy-Weinberg Principle. On the contrary, BS populations are in the state of equilibrium, which is manifested, in similar values of <em>He </em>= <em>0.262 </em>and <em>Ho </em>= <em>0.264</em>.

Detection of the eastern pygmy-possum Cercartetus nanus (Marsupialia: Burramyidae) at Barren Grounds Nature Reserve, New South Wales.

2005 ◽  
Vol 27 (1) ◽  
pp. 85 ◽  
Author(s):  
JM Harris ◽  
RL Goldingay
Keyword(s):  
New South ◽  
Survey Methods ◽  
Conservation Status ◽  
New South Wales ◽  
Detection Methods ◽  
Isolated Populations ◽  
South Eastern ◽  
Nest Boxes ◽  
South Wales ◽  
Cercartetus Nanus

THE eastern pygmy-possum (Cercartetus nanus) has an extensive distribution, from south-eastern Queensland to south-eastern South Australia, and also into Tasmania (Strahan 1995). Despite this it is rarely detected in fauna surveys (Bowen and Goldingay 2000). This rarity in detection suggested that the species may be characterised by small and isolated populations, and therefore vulnerable to extinction. Consequently, it became listed as a 'Vulnerable' species in New South Wales (NSW) in 2001. Unless resolved, the low rate of detection of C. nanus will continue to hinder the acquisition of basic ecological information that is needed to more clearly define its conservation status and that is fundamental to the development of a recovery plan. An extensive body of survey data for NSW involving C. nanus has been reviewed by Bowen and Goldingay (2000). Among a range of survey methods aimed at detecting this species, trapping within flowering banksias and checking installed nest-boxes had the highest rates of detection. Indeed, one study in northern NSW captured 98 individuals over a 3- year period from within nest-boxes (Bladon et al. 2002). All other studies detected fewer than 15 C. nanus. It is clear that further research is required to investigate the effectiveness of a range of detection methods.

Geographic dimorphism in the mountain brushtail possum (Trichosurus caninus): the case for a new species

2002 ◽  
Vol 50 (4) ◽  
pp. 369 ◽  
Author(s):  
D. B. Lindenmayer ◽  
J. Dubach ◽  
K. L. Viggers
Keyword(s):  
New Species ◽  
New South ◽  
New South Wales ◽  
Distinct Species ◽  
Genetic Distances ◽  
Brushtail Possum ◽  
Genetic Characteristics ◽  
Simple Index ◽  
South Wales ◽  
Eastern Australia

The morphological and genetic characteristics of the mountain brushtail possum (Trichosurus caninus) are described for animals from a range of locations throughout its known geographic distribution in eastern Australia. Although there is considerable variation among populations, unequivocal morphological and genetic differences exist between northern and southern populations of the species. Specimens from southern populations (from Victoria) have a significantly (P < 0.001) larger ear conch, a significantly (P < 0.001) longer pes, and a significantly (P < 0.001) shorter tail than do specimens from northern populations (from New South Wales and Queensland). Animals can be clearly distinguished using a simple index based on these three morphological measures, which are gathered from live animals. North–south dimorphism is strongly supported by patterns in genetic data that show genetic distances of 2.7–3.0% between the southern and northern populations. The combined outcomes of morphological and genetic analyses suggest the existence of two distinct species. We recommend that the northern form, distributed from central New South Wales north to central Queensland, retain the name Trichosurus caninus; the southern form from Victoria is described here as Trichosurus cunninghami, sp. nov. The common names of these new species should be the 'short-eared possum' and the 'mountain brushtail possum', respectively.

The genetic diversity and distinctiveness of the Yellow-footed Rock-wallaby Petrogale xanthopus (Gray, 1854) in New South Wales

1998 ◽  
Vol 4 (2) ◽  
pp. 164 ◽  
Author(s):  
Lisa C. Pope ◽  
Andy Sharp ◽  
Craig Moritz
Keyword(s):  
Genetic Diversity ◽  
Threatened Species ◽  
New South ◽  
New South Wales ◽  
Species Conservation ◽  
Habitat Disturbance ◽  
European Settlement ◽  
South Wales ◽  
Feral Animals ◽  
Species Being

Yellow-footed Rock-wallabies (YFRW) Petrogale xanthopus have declined in numbers since European settlement from past hunting for skins, habitat disturbance and predation and competition with feral animals (Gordon et al. 1978, 1993; Copley 1983; Henzell 1990). This has led to the species being classed as potentially vulnerable to extinction in Australia (Kennedy 1992), and endangered in New South Wales (Schedule 1, Threatened Species Conservation Act, 1995).

Isozyme diversity in large and isolated populations of Luma apiculata (Myrtaceae) in north-western Patagonia, Argentina

2005 ◽  
Vol 53 (8) ◽  
pp. 781 ◽  
Author(s):  
Mayra S. Caldiz ◽  
Andrea C. Premoli
Keyword(s):  
Genetic Variation ◽  
Isolated Populations ◽  
Isozyme Electrophoresis ◽  
Wahlund Effect ◽  
Rivers And Lakes ◽  
Large Populations ◽  
Vegetative Spread ◽  
Number Of Individuals ◽  
North Western ◽  
Isozyme Diversity

We evaluated the amount and distribution of genetic variation in large and small isolated populations of Luma apiculata (DC.) Burret (Myrtaceae) in north-western Patagonia. The hypothesis tested was that isolated smaller populations were more affected by drift and isolation than large stands. Higher genetic diversity was predicted in the latter. Fresh leaf material for isozyme electrophoresis was collected from 30 individuals in four isolated and two large and continuous stands (Quetrihue Peninsula and Punta Norte, Isla Victoria). Five subpopulations were sampled in both large stands, and in addition, three regeneration gaps in Punta Norte. Eleven loci were resolved; 91% were polymorphic in at least one population. Isolated and large populations had similar levels of genetic variation. Reduced observed heterozygosity and elevated inbreeding were measured in subpopulations and regeneration gaps within dense stands. Although small populations consist of a reduced number of individuals they are mostly coastal populations nearby rivers and lakes that may maintain considerable gene flow with other faraway populations counteracting the effects of drift. In addition to potential selfing, increased inbreeding within large populations and regeneration gaps may be due to an intra-population Wahlund effect from local seedling establishment and vegetative spread, resulting in clustered cohorts of similar genotypes.

Range and habitat associations of the native macroalga Caulerpa filiformis in New South Wales, Australia

2015 ◽  
Vol 66 (11) ◽  
pp. 1018 ◽  
Author(s):  
Tim M. Glasby ◽  
Peter. T. Gibson ◽  
Gregory West ◽  
Peter Davies ◽  
Sofietje Voerman
Keyword(s):  
New South ◽  
New South Wales ◽  
Habitat Associations ◽  
Disjunct Distribution ◽  
Species Introduction ◽  
Isolated Populations ◽  
Rocky Reefs ◽  
South Wales ◽  
Green Seaweed ◽  
Natural Range

Caulerpa filiformis is a green seaweed found in New South Wales (NSW, Australia), South Africa, Mozambique and Peru. It has been suggested that the abundance of the species has increased in NSW over recent decades. Extensive aerial and diver surveys identified a 500-km northerly extension to the range of C. filiformis in NSW (to 28°21′S) compared with previous records. The alga has a disjunct distribution with small isolated populations around rocky headlands in far northern NSW, but then no apparent populations for 350km southwards. The far northern populations could be the result of recent human-mediated transport (a species introduction), or were simply not detected previously. The increased distribution around the previous northerly limit is likely a natural range expansion. The distribution of C. filiformis in NSW and globally seems confined to a temperature range of ~16–23°C. We found no relationship between abundance of C. filiformis and human population or oceanic chlorophyll-a (a surrogate for nutrient availability). We demonstrate that C. filiformis is predominately subtidal, being found along sections of coastline where there is a mixture of rocky reefs and beaches. It is argued that sand movement may have facilitated increases in abundance of C. filiformis.

Crop to wild gene flow and genetic diversity in a vulnerable Macadamia (Proteaceae) species in New South Wales, Australia

2015 ◽  
Vol 191 ◽  
pp. 504-511 ◽  
Author(s):  
Katie O'Connor ◽  
Michael Powell ◽  
Catherine Nock ◽  
Alison Shapcott
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
New South ◽  
New South Wales ◽  
South Wales

Consequences of long- and short-term fragmentation on the genetic diversity and differentiation of a late successional rainforest conifer

2011 ◽  
Vol 59 (4) ◽  
pp. 351 ◽  
Author(s):  
Rohan Mellick ◽  
Andrew Lowe ◽  
Maurizio Rossetto
Keyword(s):  
Genetic Diversity ◽  
New South ◽  
Demographic Stochasticity ◽  
Niche Modelling ◽  
Lag Effects ◽  
South Wales ◽  
Unique System ◽  
Genetic Diversity And Structure ◽  
Modelling Techniques ◽  
Diversity Estimates

The east Australian rainforests provide a unique system with which to study historic climate-driven habitat fragmentation. The long life span of rainforest conifers and consequent lag effects on genetic variation, offer insights into demographic stochasticity in small populations and persistence in increasingly fragmented systems. Microsatellite markers were used to investigate the genetic diversity and structure of Podocarpus elatus (Podocarpaceae), a long-lived rainforest conifer endemic to Australia. Twenty-seven populations throughout the east Australian rainforests were screened and two divergent regions separated by the dry Clarence River valley (New South Wales) were discovered. This biogeographic barrier may be referred to as the Clarence River Corridor. Niche modelling techniques were employed to verify the incidence of habitat divergence between the two regions. Significantly high inbreeding was detected throughout the species range with no evidence of recent bottlenecks. Most of the diversity in the species resides between individuals within populations, which suggest the species would be sensitive to the adverse effects of inbreeding, yet evidence suggests that these populations have been small for several generations. Slightly higher diversity estimates were found in the southern region, but it is likely that the species survived historic population contraction in dispersed refugia within each of these genetically differentiated regions.

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