scholarly journals Long-term fluctuations in distribution and populations of a threatened rodent (Pseudomys novaehollandiae) in coastal woodlands of the Otway Ranges, Victoria: a regional decline or extinction?

2018 ◽  
Vol 40 (2) ◽  
pp. 281 ◽  
Author(s):  
Barbara A. Wilson ◽  
Mandy Lock ◽  
Mark J. Garkaklis
Keyword(s):  
Habitat Fragmentation ◽  
Management Strategies ◽  
Fire Regimes ◽  
High Density ◽  
Intensive Management ◽  
Population Declines ◽  
Causal Factors ◽  
European Settlement ◽  
Average Rainfall

Since European settlement Australian native rodents have experienced dramatic extinctions and declines. We investigated long-term population and distribution changes during 1981–2003, and known or potential causal factors of decline in the vulnerable New Holland mouse (Pseudomys novaehollandiae). We found that populations (n = 8) were extant for 1–6 years and were predominantly small, localised and extinction prone. High-density populations occurred after above-average rainfall but declined precipitously during drought. Wildfire resulted in the extirpation of some populations, while others survived in unburnt refugia. We propose that post-fire vegetation (3–7 years) contemporaneous with above-average rainfall delivered productive habitat resulting in both a population irruption, and recovery after wildfire. Population declines occurred in drought periods. Recent trapping at 42 sites (2013–17) failed to record any New Holland mice. The species has not been recorded since 2003. Recovery is unlikely without intensive management, focussed on remnant or reintroduced populations, including protection from habitat fragmentation and inappropriate fire regimes. Prevention of extinction of the species throughout its southern range will require similar management strategies.

Decline of the dasyurid marsupial Antechinus minimus maritimus in south-east Australia: implications for recovery and management under a drying climate

2017 ◽  
Vol 65 (4) ◽  
pp. 203 ◽  
Author(s):  
Barbara A. Wilson ◽  
Lily Zhuang-Griffin ◽  
Mark J. Garkaklis
Keyword(s):  
Management Strategies ◽  
Coastal Dunes ◽  
Fire Regimes ◽  
High Density ◽  
Current Status ◽  
Fragmented Habitat ◽  
Live Trapping ◽  
Species Survival ◽  
Long Term Studies

Our understanding of recent extinctions and declines of Australian mammals is poor, particularly where there is a paucity of data to quantify change. The swamp antechinus (A. m. maritimus) has a fragmented, coastal distribution in south-east Australia. Although long-term studies (1975–2007) of this vulnerable species were conducted in the eastern Otways, its current status was unclear. We assessed the success of live trapping and camera trapping (2013–17) at 42 sites, 19 where the species was trapped previously. Between 2013 and 2015 A. m. maritimus was recorded at only 6 sites (n = 8), but at none in 2016–17. Assessment of long-term changes found that high-density populations occurred after above-average rainfall, and both low- and high-density populations collapsed after wildfire, after low rainfall, and in fragmented habitat. The species may now be restricted to very small populations in refuges such as coastal dunes, and predicted low rainfall and increased burning frequency pose major threats to the species’ survival. Recovery is unlikely without targeted management, including predator control and protection from inappropriate fire regimes and habitat fragmentation. If similar declines have been experienced across the species’ range, prevention of extinction of the species will require similar management strategies.

Responses of Australian Mammals to Disturbance: A Review.

1999 ◽  
Vol 21 (1) ◽  
pp. 87
Author(s):  
B.A. Wilson ◽  
G.R. Friend
Keyword(s):  
Climatic Factors ◽  
Fire Regimes ◽  
Timber Harvesting ◽  
Response Patterns ◽  
Population Declines ◽  
Critical Elements ◽  
European Settlement ◽  
Mammal Fauna ◽  
Introduced Predators ◽  
Adaptive Challenges

The Australian native mammal fauna has evolved in an environment where 'natural' or endogenous disturbance is ongoing and widespread, be it fire, flood, drought or cyclones. Since European settlement, however, the type, scale, frequency and intensity of disturbance has changed and added a new suite of exogenous impacts including introduced predators and herbivores, vegetation clearance, habitat fragmentation, altered fire regimes, grazing and timber harvesting. This has presented novel and significant adaptive challenges to native mammals over a compressed time-scale, resulting in major extinctions, population declines and disruption to community structure. In this paper we examine the ecology of Australian mammals in the context of these new disturbances, and compare the response patterns observed, and assess the processes operating. In general, Australian mammalian successional patterns are closely tied to vegetation regeneration, which is related to the degree of disruption. Disturbances such as predation do not fall within this pattern. Mammalian successional states vary between different disturbance types within an ecosystem, depending on the critical elements of vegetation structure and composition. Landscape and climatic factors also affect successional patterns and need to be further investigated.

Temperate Eucalypt Woodlands: a Review of Their Status, Processes Threatening Their Persistence and Techniques for Restoration

1997 ◽  
Vol 45 (6) ◽  
pp. 949 ◽  
Author(s):  
Colin J. Yates ◽  
Richard J. Hobbs
Keyword(s):  
Saline Water ◽  
Local Population ◽  
Fire Regimes ◽  
Past Research ◽  
Livestock Grazing ◽  
Population Declines ◽  
European Settlement ◽  
Eastern Australia ◽  
Eucalypt Woodlands ◽  
Few Data

Temperate eucalypt woodlands were once widespread throughout southern Australia and Tasmania. Following European settlement, woodlands were cleared for agriculture, or grazed and converted to pasture. In the wheatbelts of south-western and south-eastern Australia, woodlands have been almost completely eliminated from the landscape with as little as 3% of some woodland types remaining. As a consequence, some temperate eucalypt woodland communities are amongst the most poorly conserved ecosystems in Australia. The main effect of widespread clearing and grazing has been the loss of habitat. This has had a devastating impact on the woodland flora and fauna. A number of species have become extinct and many are threatened; many others have undergone regional and local population declines. Woodlands now occur throughout much of their former range as remnants of varying size, quality and isolation. Many of these are under threat from further clearing, rising saline water tables and increased inundation, livestock grazing, nutrient enrichment, soil structural decline, altered fire regimes and the invasion of exotic weeds. The degradation and loss of biodiversity in temperate eucalypt woodlands will continue unless clearing stops and the management of remnants changes; this will invariably involve ecological restoration both at the patch and landscape level. The review discusses approaches to restoration and reveals that there are few data in the published literature describing techniques for reversing degrading processes and restoring diversity structure and function in remnant woodlands. This information is urgently needed. Past research on temperate eucalypt woodlands has focused on identifying the processes of degradation and these are now relatively well documented. There is a need to shift the focus of research to developing solutions for these problems.

Declines in populations of Australia's endemic tropical rainforest frogs

1994 ◽  
Vol 1 (1) ◽  
pp. 66 ◽  
Author(s):  
Stephen J. Richards ◽  
Keith R. McDonald ◽  
Ross A. Alford
Keyword(s):  
Tropical Rainforest ◽  
Management Strategies ◽  
Inorganic Ions ◽  
Tropical Rainforests ◽  
Population Declines ◽  
Term Survival ◽  
Feral Pigs ◽  
Frog Species ◽  
History Of

Comparisons of present and past occurrences suggest that populations of six frog species endemic to the tropical rainforests of northern Queensland have declined during the past ten years. Most declines have occurred at high altitudes in the southern portions of the tropical rainforest. An extensive survey conducted during the summer of 1991-1992 did not locate any individuals of two upland species, Litoria nyakalensis and Taudactylus rheophilus. Another upland species, T. acutirostris, which formerly was widely distributed, appears to have declined in rainforests south of the Daintree River. Three species (Litoria nannotis, L. rheocola and Nyctimystes dayi) were absent from most upland sites south of the Daintree River, but were common at lowland sites and at all sites north of the Daintree River. Aspects of water chemistry, including inorganic ions, heavy metals, and pesticide residues, were analysed for many sites. These analyses failed to identify any abnormalities that might have contributed to frog declines. Declines appear to be unrelated to the history of forestry or mining at sites, or to low rainfall in wet seasons. Levels of habitat disturbance by feral pigs appear to have increased at some sites in recent years and, either by this disturbance or through direct predation, feral pigs may have contributed to declines in some populations. However, pigs are unlikely to be the sole cause of frog population declines. Once declines have occurred, fragmentation of rainforest habitats may prevent recolonization from adjacent sites. Until causal agents associated with declines can be identified, management strategies to ensure the long-term survival of these species must involve protection of the riparian habitats in which they occur.

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

Petroclival meningiomas: long-term outcomes of multimodal treatments and management strategies based on 30 years of experience at a single institution

2020 ◽  
Vol 132 (6) ◽  
pp. 1675-1682 ◽  
Author(s):  
Jin Wook Kim ◽  
Hee-Won Jung ◽  
Yong Hwy Kim ◽  
Chul-Kee Park ◽  
Hyun-Tai Chung ◽  
...  
Keyword(s):  
Adjuvant Treatment ◽  
Management Strategies ◽  
Local Tumor Control ◽  
Tumor Control ◽  
Years Of Experience ◽  
Local Tumor ◽  
Long Term Outcomes ◽  
Single Institution ◽  
Petroclival Meningiomas

OBJECTIVEA thorough investigation of the long-term outcomes and chronological changes of multimodal treatments for petroclival meningiomas is required to establish optimal management strategies. The authors retrospectively reviewed the long-term clinical outcomes of patients with petroclival meningioma according to various treatments, including various surgical approaches, and they suggest treatment strategies based on 30 years of experience at a single institution.METHODSNinety-two patients with petroclival meningiomas were treated surgically at the authors’ institution from 1986 to 2015. Patient demographics, overall survival, local tumor control rates, and functional outcomes according to multimodal treatments, as well as chronological change in management strategies, were evaluated. The mean clinical and radiological follow-up periods were 121 months (range 1–368 months) and 105 months (range 1–348 months), respectively.RESULTSA posterior transpetrosal approach was most frequently selected and was followed in 44 patients (48%); a simple retrosigmoid approach, undertaken in 30 patients, was the second most common. The initial extent of resection and following adjuvant treatment modality were classified into 3 subgroups: gross-total resection (GTR) only in 13 patients; non-GTR treatment followed by adjuvant radiosurgery or radiation therapy (non-GTR+RS/RT) in 56 patients; and non-GTR without adjuvant treatment (non-GTR only) in 23 patients. The overall progression-free survival rate was 85.8% at 5 years and 81.2% at 10 years. Progression or recurrence rates according to each subgroup were 7.7%, 12.5%, and 30.4%, respectively.CONCLUSIONSThe authors’ preferred multimodal treatment strategy, that of planned incomplete resection and subsequent adjuvant radiosurgery, is a feasible option for the management of patients with large petroclival meningiomas, considering both local tumor control and postoperative quality of life.

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

scholarly journals Coronary artery aneurysms: outcomes following medical, percutaneous interventional and surgical management

Open Heart ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. e001440
Author(s):  
Shameer Khubber ◽  
Rajdeep Chana ◽  
Chandramohan Meenakshisundaram ◽  
Kamal Dhaliwal ◽  
Mohomed Gad ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Surgical Management ◽  
Medical Management ◽  
Cox Regression ◽  
Artery Bypass ◽  
Management Strategies ◽  
Coronary Artery Aneurysms ◽  
Kaplan Meier

BackgroundCoronary artery aneurysms (CAAs) are increasingly diagnosed on coronary angiography; however, controversies persist regarding their optimal management. In the present study, we analysed the long-term outcomes of patients with CAAs following three different management strategies.MethodsWe performed a retrospective review of patient records with documented CAA diagnosis between 2000 and 2005. Patients were divided into three groups: medical management versus percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG). We analysed the rate of major cardiovascular and cerebrovascular events (MACCEs) over a period of 10 years.ResultsWe identified 458 patients with CAAs (mean age 78±10.5 years, 74.5% men) who received medical therapy (N=230) or underwent PCI (N=52) or CABG (N=176). The incidence of CAAs was 0.7% of the total catheterisation reports. The left anterior descending was the most common coronary artery involved (38%). The median follow-up time was 62 months. The total number of MACCE during follow-up was 155 (33.8%); 91 (39.6%) in the medical management group vs 46 (26.1%) in the CABG group vs 18 (34.6%) in the PCI group (p=0.02). Kaplan-Meier survival analysis showed that CABG was associated with better MACCE-free survival (p log-rank=0.03) than medical management. These results were confirmed on univariate Cox regression, but not multivariate regression (OR 0.773 (0.526 to 1.136); p=0.19). Both Kaplan-Meier survival and regression analyses showed that dual antiplatelet therapy (DAPT) and anticoagulation were not associated with significant improvement in MACCE rates.ConclusionOur analysis showed similar long-term MACCE risks in patients with CAA undergoing medical, percutaneous and surgical management. Further, DAPT and anticoagulation were not associated with significant benefits in terms of MACCE rates. These results should be interpreted with caution considering the small size and potential for selection bias and should be confirmed in large, randomised trials.

scholarly journals Tracking Changes on Soil Structure and Organic Carbon Sequestration after 30 Years of Different Tillage and Management Practices

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 291
Author(s):  
Ramón Bienes ◽  
Maria Jose Marques ◽  
Blanca Sastre ◽  
Andrés García-Díaz ◽  
Iris Esparza ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Organic Carbon ◽  
Management Practices ◽  
Management Strategies ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Conventional Tillage ◽  
Soil Parameters ◽  
Wilting Point

Long-term field trials are essential for monitoring the effects of sustainable land management strategies for adaptation and mitigation to climate change. The influence of more than thirty years of different management is analyzed on extensive crops under three tillage systems, conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and with two crop rotations, monoculture winter-wheat (Triticum aestivum L.) and wheat-vetch (Triticum aestivum L.-Vicia sativa L.), widely present in the center of Spain. The soil under NT experienced the largest change in organic carbon (SOC) sequestration, macroaggregate stability, and bulk density. In the MT and NT treatments, SOC content was still increasing after 32 years, being 26.5 and 32.2 Mg ha−1, respectively, compared to 20.8 Mg ha−1 in CT. The SOC stratification (ratio of SOC at the topsoil/SOC at the layer underneath), an indicator of soil conservation, increased with decreasing tillage intensity (2.32, 1.36, and 1.01 for NT, MT, and CT respectively). Tillage intensity affected the majority of soil parameters, except the water stable aggregates, infiltration, and porosity. The NT treatment increased available water, but only in monocropping. More water was retained at the permanent wilting point in NT treatments, which can be a disadvantage in dry periods of these edaphoclimatic conditions.

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