scholarly journals Recently Naturalized Paraserianthes lophantha subsp. lophantha Displays Contrasting Genetic Diversity and Climate Relationships Compared to Native Populations

Diversity ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 422
Author(s):  
Gillian K. Brown ◽  
Elizabeth A. James ◽  
Catherine L. Simmons ◽  
Collin W. Ahrens
Keyword(s):  
Management Strategies ◽  
Distribution Management ◽  
Eastern Australia ◽  
Genetic Patterns ◽  
Native Populations ◽  
Nuclear Microsatellite ◽  
Chloroplast Dna Markers ◽  
Genetic Signal ◽  
Source Populations ◽  
Number Of Individuals

Paraseriantheslophantha subsp. lophantha (Leguminosae) is native to southwestern Australia, but has become naturalized in eastern Australia and in countries around the world. Previous studies have investigated the introduction sources for P. lophantha subsp. lophantha overseas, but here, we expand on the knowledge of genetic patterns in its native and naturalized range in Australia. Genetic patterns were examined using nine nuclear microsatellite loci and three chloroplast DNA markers. The native populations exhibited phylogeographic patterns, including north-south differentiation, and a genetic signal related to temperature gradients. Naturalized Australian populations displayed lower overall genetic variation and no phylogeographic patterns. Several naturalized populations separated by large distances (350–650 km) shared multi-locus genotypes, supporting the notion of a shared source of germplasm and possible inbreeding due to human-mediated introductions from a limited number of individuals and/or source populations within the native range. We advocate that management strategies are tailored to the distinct conservation aims underpinning conservation in native or naturalized populations. Within the native distribution, management should have a long-term aim to replicate historical evolutionary processes, whereas in naturalized populations, immediate actions may be required to reduce the abundance of P. lophantha subsp. lophantha and minimize its invasive impact on the recipient vegetation.

Genetic structure of Gahnia radula (Cyperaceae), a key sedge for revegetation

2017 ◽  
Vol 65 (2) ◽  
pp. 128
Author(s):  
Alex Arnold ◽  
Andrea Kodym ◽  
Nancy M. Endersby-Harshman ◽  
John Delpratt ◽  
Ary A. Hoffmann
Keyword(s):  
Genetic Variation ◽  
Adaptive Potential ◽  
Genetic Studies ◽  
Potential Source ◽  
Landscape Processes ◽  
Disturbed Areas ◽  
Eastern Australia ◽  
Genetic Patterns ◽  
Source Populations ◽  
High Level

Genetic studies can help guide effective ecological restoration by identifying potential source populations that contain the genetic variation necessary for adaptive potential, based on past landscape processes. Here we investigate genetic patterns in Gahnia radula (R.Br.) Benth., a sedge from south-eastern Australia that has potential for revegetation of disturbed areas. We developed microsatellite markers for this species and used them to show that it propagates mostly in a clonal manner. Levels of genetic variability differed between populations and the spatial scale of this variability within these populations is identified. A population used in recent restoration efforts and which sets seed has a particularly high level of variability. Recommendations are developed for sourcing material when using this sedge for revegetation.

scholarly journals A Bayesian approach to the identification of panmictic populations and the assignment of individuals

2001 ◽  
Vol 78 (1) ◽  
pp. 59-77 ◽  
Author(s):  
KEVIN J. DAWSON ◽  
KHALID BELKHIR
Keyword(s):  
Bayesian Approach ◽  
Posterior Distribution ◽  
Clustering Algorithm ◽  
Maximum Likelihood Method ◽  
Likelihood Method ◽  
Marker Loci ◽  
Hierarchical Clustering Algorithm ◽  
Source Populations ◽  
Low Dimensional ◽  
Number Of Individuals

We present likelihood-based methods for assigning the individuals in a sample to source populations, on the basis of their genotypes at co-dominant marker loci. The source populations are assumed to be at Hardy–Weinberg and linkage equilibrium, but the allelic composition of these source populations and even the number of source populations represented in the sample are treated as uncertain. The parameter of interest is the partition of the set of sampled individuals, induced by the assignment of individuals to source populations. We present a maximum likelihood method, and then a more powerful Bayesian approach for estimating this sample partition. In general, it will not be feasible to evaluate the evidence supporting each possible partition of the sample. Furthermore, when the number of individuals in the sample is large, it may not even be feasible to evaluate the evidence supporting, individually, each of the most plausible partitions because there may be many individuals which are difficult to assign. To overcome these problems, we use low-dimensional marginals (the ‘co-assignment probabilities’) of the posterior distribution of the sample partition as measures of ‘similarity’, and then apply a hierarchical clustering algorithm to identify clusters of individuals whose assignment together is well supported by the posterior distribution. A binary tree provides a visual representation of how well the posterior distribution supports each cluster in the hierarchy. These methods are applicable to other problems where the parameter of interest is a partition of a set. Because the co-assignment probabilities are independent of the arbitrary labelling of source populations, we avoid the label-switching problem of previous Bayesian methods.

Crop stubbles are as important for sheep production as annual pastures in the Victorian Mallee

2006 ◽  
Vol 46 (8) ◽  
pp. 993 ◽  
Author(s):  
S. M. Robertson
Keyword(s):  
Plant Density ◽  
Cropping Systems ◽  
Management Strategies ◽  
Simulation Modelling ◽  
Annual Rainfall ◽  
Pasture Management ◽  
Pasture Production ◽  
Eastern Australia ◽  
Sheep Production ◽  
The Impact

The impact of different management strategies on production and profit can be evaluated with knowledge of how sheep production responds to changes in the available feed base and sheep or pasture management. This study aimed to quantify on-farm pasture and sheep production in mixed sheep and cropping systems in the Victorian Mallee of south-eastern Australia (325 ± 50 mm annual rainfall) as a prelude to computer simulation modelling. During 2001 (average rainfall) and 2002 (extreme drought) pasture production, the feed base and sheep production were monitored in 15 paddocks on 5 properties located across the region. Crop stubbles were the major source of feed for 6 months of the year, enabling ewes to maintain liveweight. There was more variation in pasture parameters between paddocks at the 1 location than between locations. The botanical composition, plant density, soil fertility and management were key variables associated with between-paddock variation in pasture production. Variation in pasture production between years was larger than within-year differences. In contrast, stocking rates were not much lower in the drought year of 2002 than in 2001. This study suggests there is potential for management to improve pasture production, and demonstrates the importance of feed sources other than annual pasture for sheep production in environments where the annual pasture growing season is short.

Too close for comfort: a fishway exit and a hydro-power station inlet

2010 ◽  
Vol 61 (1) ◽  
pp. 23 ◽  
Author(s):  
Ivor G. Stuart ◽  
John D. Koehn ◽  
Tim A. O'Brien ◽  
John A. McKenzie ◽  
Gerry P. Quinn
Keyword(s):  
Management Strategies ◽  
Field Testing ◽  
High Water ◽  
Fish Passage ◽  
Native Fish ◽  
Power Station ◽  
Hydro Power ◽  
Murray River ◽  
Eastern Australia ◽  
Radio Transmitters

A major environmental issue for hydro-electric power generation is passage of fish through turbines, or entrainment onto trash racks. At Yarrawonga Weir, on the upper Murray River in south-eastern Australia, the positioning of a fish lock resulted in the potential for upstream migrating fish to be swept back into the adjacent power station by cross flows. In 2004, a 4.5-m long steel extension flume was attached to the exit to alleviate this problem. To determine the fate of native fish after exiting the extension flume, 72 individuals (305–1015 mm long) were implanted with radio-transmitters and released into the fish lock exit channel. In 2004 (power station inflows 10 300 ML day–1), the majority of fish exited successfully (44 of 45) and only a single fish (2%) was entrained into the power station. In 2005 (power station inflows 12 000 ML day–1), fish again exited successfully (26 of 27) but with a higher proportion entrained (5 of 27; 18%). This reduced success appeared to be related to strong transverse flows with high water velocities adjacent to the fish lock exit. The efficiency of fish passage at this site might be improved by altering water management strategies, integrating engineering and fish biology, and through field-testing of proposed solutions.

When will integrated pest management strategies be adopted? Example of the development and implementation of integrated pest management strategies in cropping systems in Victoria

2008 ◽  
Vol 48 (12) ◽  
pp. 1601 ◽  
Author(s):  
Paul A. Horne ◽  
Jessica Page ◽  
Cam Nicholson
Keyword(s):  
Integrated Pest Management ◽  
Pest Management ◽  
Information Transfer ◽  
Cropping Systems ◽  
Management Strategies ◽  
Sufficient Information ◽  
Motivation To Change ◽  
Implementing Change ◽  
Eastern Australia ◽  
Changing Practices

This paper discusses the development and implementation of integrated pest management (IPM) strategies for broadacre cropping in Victoria, Australia, with reference to other crops and also the levels of adoption of IPM in Australia and overseas. Levels and rates of adoption are mostly low but with some exceptions. The reasons for differing levels of adoption include the failure of strategies to successfully deal with all pests, the lack of motivation to change to using IPM given current successful pesticide-based controls, and the poor availability of IPM advisors in the field. This paper outlines how IPM strategies for wheat, barley and canola crops were developed and implemented using a collaborative approach between farmers, agronomists and entomologists. It was found that although there were no existing specific IPM strategies for the crops grown in the region of south-eastern Australia, there was sufficient information for farmers to start using an IPM approach. This paper gives a case study of implementing change to IPM from conventional pesticide spraying, including the development of a course in IPM for growers and agronomists. It focuses on the process of changing practices and information transfer rather than on entomological details.

Habitat use and movements of Australian grayling (Prototroctes maraena) in a Victorian coastal stream

2018 ◽  
Vol 69 (8) ◽  
pp. 1259 ◽  
Author(s):  
D. R. Dawson ◽  
W. M. Koster
Keyword(s):  
Habitat Use ◽  
Conservation Management ◽  
Radio Telemetry ◽  
Management Strategies ◽  
Movement Ecology ◽  
Ecological Requirements ◽  
Management Actions ◽  
Eastern Australia ◽  
The World ◽  
Australian Grayling

Riverine fishes are among the most imperilled fauna in the world; however, for many species, there is little or no understanding of their ecological requirements. The Australian grayling (Prototroctes maraena) is a small diadromous fish endemic to rivers in south-eastern Australia that has declined considerably in range and abundance and is listed as threatened nationally. To improve understanding of the species’ movement ecology and to inform the development of conservation management actions, we examined the day-to-day movements and habitat use of Australian grayling (n=7) over 8 weeks by using radio-telemetry. Tagged individuals of Australian grayling typically occupied restricted (i.e. tens to hundreds of metres) reaches of stream, and were mostly located in moderate- to fast-flowing habitats (i.e. glide or run), although, at night, use of slower-flowing habitats (i.e. pools) increased. They also undertook longer-distance downstream movements during a period of increased streamflow. Incorporation of such information into management strategies has the potential to improve our capacity to maintain or re-instate the conditions required to conserve and restore Australian grayling populations.

Invasive predators represent the greatest extinction threat to the endangered northern bettong (Bettongia tropica)

2018 ◽  
Vol 45 (3) ◽  
pp. 208 ◽  
Author(s):  
Tegan Whitehead ◽  
Karl Vernes ◽  
Miriam Goosem ◽  
Sandra E. Abell
Keyword(s):  
Climate Change ◽  
Synergistic Effects ◽  
Management Strategies ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Active Management ◽  
Feral Cats ◽  
Juvenile Mortality ◽  
Management Actions ◽  
Eastern Australia

Context Identification of key threats to endangered species is vital for devising effective management strategies, but may be hindered when relevant data is limited. A population viability approach may overcome this problem. Aims We aimed to determine the population viability of endangered northern bettongs (Bettongia tropica) in north-eastern Australia. We also assessed the key threats to the population resilience and how the population viability responds to increases in mortality rates and changes in fire and drought frequency. Methods Using population viability analysis (PVA) we modelled survival probability of B. tropica populations under likely scenarios, including: (1) increased predation; (2) changes in drought and fire frequency predicted with anthropogenic climate change; and (3) synergistic effects of predation, fire and drought. Key results Population viability models suggest that populations are highly vulnerable to increases in predation by feral cats (Felis catus), and potentially red fox (Vulpes vulpes) should they colonise the area, as juvenile mortality is the main age class driving population viability. If B. tropica become more vulnerable to predators during post-fire vegetation recovery, more frequent fires could exacerbate effects of low-level cat predation. In contrast, it was predicted that populations would be resilient to the greater frequency of droughts expected as a result of climate change, with high probabilities of extinctions only predicted under the unprecedented and unlikely scenario of four drought years in 10. However, since drought and fire are interlinked, the impacts of predation could be more severe with climate change should predation and fire interact to increase B. tropica mortality risk. Conclusion Like other Potoroids, B. tropica appear highly vulnerable to predation by introduced mammalian predators such as feral cats. Implications Managers need information allowing them to recognise scenarios when populations are most vulnerable to potential threats, such as drought, fire and predation. PVA modelling can assess scenarios and allow pro-active management based on predicted responses rather than requiring collection of extensive field data before management actions. Our analysis suggests that assessing and controlling predator populations and thereby minimising predation, particularly of juveniles, should assist in maintaining stability of populations of the northern bettong.

scholarly journals Kendali Optimal Pada Model Penyebaran Penyakit Difteri dengan Tingkat Imunitas Alami Pada Individu Terpapar

2021 ◽  
Vol 18 (1) ◽  
pp. 1-10
Author(s):  
N Izzati ◽  
A Andriani
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Mortality Rate ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Management Strategies ◽  
Immunization Coverage ◽  
Natural Immunity ◽  
Exposed Population ◽  
Number Of Individuals

Indonesia is one of the countries where has not been free from diphtheria outbreak. During 2017-2019, there were 2870 diphtheria cases with 96 deaths. With the mortality rate 5-20%, makes studies regarding diphtheria prevention and management strategies become important to do. In this study, a SEIQR mathematical model was constructed by considering the factor of natural immunity rate in exposed individuals. Then, by considering the complete basic immunization coverage and the proportion of the number of individuals with natural immunity rate as control variables, the optimal control problem is formulated to minimize the number of infected poopulation. Optimal control using DOTcvpSB toolbox obtained that the number of exposed population in the model decreased from 4.9% to 0.75%, and the number of infected population decreased from 3.1% to 0.32%.

scholarly journals SPATIAL STRUCTURE OF Theobroma subincanumMart. AND Theobromaspeciosum Willd. ex Spreng.IN THE PARQUE NACIONAL DO JURUENA, MATO GROSSO STATE, BRAZIL

2017 ◽  
Vol 41 (1) ◽  
Author(s):  
Juliana de Freitas Encinas Dardengo ◽  
Ana Aparecida Bandini Rossi ◽  
Carolina Joana da Silva ◽  
Marcos Silveira
Keyword(s):  
Spatial Distribution ◽  
Management Strategies ◽  
Basal Area ◽  
Average Diameter ◽  
Random Pattern ◽  
Conservation Areas ◽  
Forest Environment ◽  
Horizontal Structure ◽  
Mato Grosso ◽  
Number Of Individuals

ABSTRACT Analysis of the spatial distribution is a very useful tool to understand the ecological behavior of the species in that it provides information that underlies management strategies and influences the population structure. To study the horizontal structure of the species T. speciosum (Cacaui) and T. subincanum (Cupui) in the "Parque Nacional do Juruena", Mato Grosso state, a 200 x 160 m grid was implemented and divided into 40 adjacent 20 x 40 m subplots. All individuals of the species under study that had DBH > 1 cm were measured. The following parameters were analyzed: number of individuals, density, total height, basal area, diametric distribution, and spatial distribution. The research sampled 165 T. speciosum trees (51.56 ind.ha-1) and 34 T. subincanum (10.62 ind.ha-1), with an average diameter of 6.72 cm and 12.44 respectively, the T. speciosum individuals showed an aggregated distribution pattern, while the T. subincanum individuals presented a random pattern. The diametric distribution of T. speciosum followed an exponential distribution in a reverse-J shaped pattern, behavior expected for a forest environment with little anthropic pressure, while T. subincanum did not follow the same pattern, though the species demonstrated to be well established in the area, with significant number of individuals in all diameter classes, thus,the results indicate the importance of conservation areas established in order to safeguard the natural environment from the pressures of anthropic actions, and also the need for studies in the region of the Amazon biome.

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