scholarly journals Habitat associations of the long-nosed potoroo (Potorous tridactylus) at multiple spatial scales

2010 ◽  
Vol 58 (5) ◽  
pp. 303 ◽  
Author(s):  
Melinda A. Norton ◽  
Kris French ◽  
Andrew W. Claridge
Keyword(s):  
Spatial Scales ◽  
Habitat Preferences ◽  
Ground Cover ◽  
Habitat Associations ◽  
Microhabitat Use ◽  
Shrub Cover ◽  
South Wales ◽  
Wide Range ◽  
Foraging Preference ◽  
Potorous Tridactylus

This study examined the coarse- and fine-scale habitat preferences of the long-nosed potoroo (Potorous tridactylus) in the Southern Highlands of New South Wales, in order to inform the management of this threatened species. Live-trapping was conducted in autumn and spring, from 2005 to 2008, at two sites. Macrohabitat preferences were examined by comparing trap success with numerous habitat attributes at each trap site. In spring 2007 and autumn 2008, microhabitat use was also examined, using the spool-and-line technique and forage digging assessments. While potoroos were trapped in a wide range of macrohabitats, they displayed some preference for greater canopy and shrub cover, and ground cover with lower floristic diversity. While most individuals also displayed preferences for various microhabitat attributes, no clear trends were evident across all individuals. Potoroos displayed some foraging preference for microhabitats with higher shrub cover densities and more open ground cover. Despite extensive fox predation risks, individual potoroos did not all preferentially utilise dense ground cover. Future management of known and potential potoroo habitat should aim to provide effective introduced predator control and enhance the diversity of vegetation attributes while avoiding practices that simplify the habitat.

Population characteristics and management of the long-nosed potoroo (Potorous tridactylus) in high-quality habitat in the Southern Highlands of New South Wales

2015 ◽  
Vol 37 (1) ◽  
pp. 67 ◽  
Author(s):  
Melinda A. Norton ◽  
Alison Prentice ◽  
Juliet Dingle ◽  
Kris French ◽  
Andrew W. Claridge
Keyword(s):  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Population Characteristics ◽  
European Settlement ◽  
South Wales ◽  
Live Trapping ◽  
Study Sites ◽  
Fox Control ◽  
Potorous Tridactylus

Since European settlement in Australia the long-nosed potoroo (Potorous tridactylus) has suffered greatly from fox predation and habitat loss, fragmentation and degradation. To better understand the threats it faces we examined the population dynamics of the potoroo at two study sites in the Southern Highlands of New South Wales over five years, using live-trapping. As neither site had experienced inappropriate habitat change for over 25 years, fox predation was considered the major threat to this population. An assessment of fox activity and diet was undertaken at both sites for comparison with potoroo abundance. Potoroos increased at both sites over time, although at one site this increase was only in density and not range. The density increase would not have been detected using camera surveys, a monitoring technique recommended for this species. The relative abundance of foxes fluctuated over the study despite fox control in one of the two sites. Analysis of fox scats at the same sites indicated high levels of predation on potoroos. Future management should aim to provide effective fox control (particularly following any fire due to the associated loss of ground cover) and improved fox monitoring to ensure an accurate understanding of what is happening to the fox population.

Spatial distribution and habitat preferences of co-occurring vertebrate species: Case study of an endangered frog and an introduced toad in Fiji.

2011 ◽  
Vol 17 (1) ◽  
pp. 68 ◽  
Author(s):  
Nunia Thomas ◽  
Clare Morrison ◽  
Linto Winder ◽  
Craig Morley
Keyword(s):  
Spatial Distribution ◽  
Habitat Management ◽  
Habitat Preferences ◽  
Habitat Associations ◽  
Ecological Data ◽  
Cane Toad ◽  
Habitat Types ◽  
Point Counts ◽  
Wide Range ◽  
The Impact

Wildlife management, particularly the conservation of threatened species, often involves habitat management and an understanding of species preferences. Much ecological data used to establish rare and endangered species distributions and/or habitat associations exists in the form of point counts which often violates the assumptions of commonly used statistical techniques. In this study, the spatial distribution and habitat preferences of an endangered, endemic frog (Platymantis vitianus — Fiji ground frog) and an introduced toad (Rhinella marina — cane toad) were observed and mapped on a 60 ha island using a grid of 232 sampling points with 50 × 20 m spacing. The Spatial Analysis by Distance Indices (SADIE) analytical tool demonstrated that despite the wide range of habitats present on Viwa Island, both ground frogs and cane toads displayed clear and defined macrohabitat preferences. Whilst both species showed a strong preference for Inocarpus fagifer forests, there was little overlap in other habitat types with the ground frogs preferring more densely vegetated forest habitats and cane toads preferring more open habitat types close to both permanent and temporary water sources. Within the I. fagifer forests, there was no evidence of overlap in the distributions of the two species. The spatial pattern evident indicates that cane toad and ground frog populations co-exist, probably due to similar habitat preferences. However, a more detailed study on the interactions between the two species within their natural environment is needed to determine the nature and magnitude of the impact of the cane toad on the ground frog.

scholarly journals On the generation of internal waves by river plumes in subcritical initial conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Mendes ◽  
J. C. B. da Silva ◽  
J. M. Magalhaes ◽  
B. St-Denis ◽  
D. Bourgault ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Internal Waves ◽  
Coastal Waters ◽  
Initial Conditions ◽  
Spatial Scales ◽  
River Plumes ◽  
Wide Range ◽  
Near Shore ◽  
Generation Mechanisms ◽  
Douro River

AbstractInternal waves (IWs) in the ocean span across a wide range of time and spatial scales and are now acknowledged as important sources of turbulence and mixing, with the largest observations having 200 m in amplitude and vertical velocities close to 0.5 m s−1. Their origin is mostly tidal, but an increasing number of non-tidal generation mechanisms have also been observed. For instance, river plumes provide horizontally propagating density fronts, which were observed to generate IWs when transitioning from supercritical to subcritical flow. In this study, satellite imagery and autonomous underwater measurements are combined with numerical modeling to investigate IW generation from an initial subcritical density front originating at the Douro River plume (western Iberian coast). These unprecedented results may have important implications in near-shore dynamics since that suggest that rivers of moderate flow may play an important role in IW generation between fresh riverine and coastal waters.

Effect of herbicides on St John's wort (Hypericum perforatum L.)

1991 ◽  
Vol 31 (4) ◽  
pp. 499 ◽  
Author(s):  
MH Campbell ◽  
BR Milne ◽  
JJ Dellow ◽  
HI Nicol
Keyword(s):  
Hypericum Perforatum ◽  
New South ◽  
Arable Land ◽  
Ground Cover ◽  
Aerial Application ◽  
St John’S Wort ◽  
Strong Trend ◽  
St John's Wort ◽  
South Wales ◽  
Hypericum Perforatum L

The effect of type of herbicide and time and rate of application on the reduction in ground cover of St John's wort (Hypericum perforatum L.) was determined at Orange, New South Wales. In January, April, July and November 1988, 8 herbicide treatments including the currently used glyphosate and picloram + 2,4-D were applied to vigorously growing H. perforaturn, and the reduction in percentage ground cover was recorded in December 1989. Ineffective herbicides (a.i./ha) were tebuthiuron, 0.8-6.4 kg; metsulfuron, 5-20 g; and paraquat + diquat, 0.4 + 0.5 kg. The addition of metsulfuron (2.5 g a.i./ha) to glyphosate (0.9 and 1.8 kg a.i./ha) did not increase the effectiveness of the latter. Effective herbicides (kg a.i./ha) were triclopyr + picloram, 0.6 + 0.2; picloram + 2,4-D, 0.2 + 0.8; glyphosate, 1.8; and triclopyr, 1.92. There was a strong trend for these herbicides to be more effective in January and November than in April and July. Based on price, effectiveness and selectivity, triclopyr + picloram would be preferred to the other herbicides for boom and spot spraying, and glyphosate would be the only herbicide suitable for aerial application prior to sowing improved pastures on non-arable land.

Effects of logging and fire on small mammals in Mumbulla State Forest, near Bega, New South Wales

1987 ◽  
Vol 14 (2) ◽  
pp. 163 ◽  
Author(s):  
D. Lunney ◽  
B. Cullis ◽  
P. Eby
Keyword(s):  
Small Mammals ◽  
New South ◽  
New South Wales ◽  
Canopy Cover ◽  
Ground Cover ◽  
First Year ◽  
Severe Effect ◽  
South Wales ◽  
Antechinus Stuartii ◽  
Rattus Fuscipes

This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate; fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire; its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.

Gibberella fujikuroi var. subglutinans. [Descriptions of Fungi and Bacteria].

1964 ◽  
Author(s):  
C. Booth
Keyword(s):  
Geographical Distribution ◽  
Sugar Cane ◽  
Stem Borer ◽  
Fruit Rot ◽  
Gibberella Fujikuroi ◽  
Stem Rot ◽  
South Wales ◽  
Pokkah Boeng ◽  
Wide Range ◽  
Southern Rhodesia

Abstract A description is provided for Gibberella fujikuroi var. subglutinans. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On several hosts of economic importance in the Gramineae; also on a wide range of hosts represented by the following families: Amaryllidaceae, Anacardiaceae, Bromeliaceae, Chenopodiaceae, Convolvulaceae, Cruciferae, Iridaceae, Leguminosae, Liliaceae, Malvaceae, Marantaceae, Musaceae, Palmae, Rosaceae, Rutaceae, Sterculiaceae (14: 708; 31: 515; 36: 501; 40: 89 and Herb. IMI). DISEASES: Causes a seedling blight, and root, stalk and kernel rot of maize; also on heads and stalks of sorghum associated with a foot and stem rot, and causing a stem rot and top rot of sugar-cane ('pokkah boeng'). Other records include a wilt of Crotalaria, a heart rot of leaves of banana and Manila hemp, and fruit rot of banana, cacao and pineapple. There appear to be no references to pathogenicity to rice. Also entomogenous on cereal stem borer larvae and other insects (27: 71; 33: 382; 38: 141, 740). GEOGRAPHICAL DISTRIBUTION: Africa (Central African Republic, Congo, Ghana, Ivory Coast, Kenya, Mauritius, Morocco, Reunion, Sierra Leone, South Africa, Southern Rhodesia, Tanganyika, Uganda); Asia (Formosa (Taiwan), Hong Kong, India, Java, Indo-China, Philippines, Syria); Australasia (Hawaii, New South Wales, New Zealand, Victoria); Europe (Czechoslovakia, Germany,? Italy, Poland, Romania); Central America & West Indies (French Antilles, Honduras, Trinidad); North America (Canada, United States); South America (Argentina, Peru). (CMI Map 191). TRANSMISSION: Both seed and soil-borne. Air-borne ascospores produced from perithecia on over-wintered plant debris or on dead stalks of sugar-cane at the beginning of the rainy season are also important sources of infection (30: 344). The pathogen may also be disseminated on pupae and adults of cereal stem borers and their parasites in sugar-cane (33: 382).

scholarly journals Persistent magnetic vortex flow at a supergranular vertex

2018 ◽  
Vol 610 ◽  
pp. A84 ◽  
Author(s):  
Iker S. Requerey ◽  
Basilio Ruiz Cobo ◽  
Milan Gošić ◽  
Luis R. Bellot Rubio
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Vortex Flow ◽  
Spatial Scales ◽  
Magnetic Vortex ◽  
Magnetic Feature ◽  
Magnetic Element ◽  
Flow Maps ◽  
Wide Range ◽  
Intensity Images

Context. Photospheric vortex flows are thought to play a key role in the evolution of magnetic fields. Recent studies show that these swirling motions are ubiquitous in the solar surface convection and occur in a wide range of temporal and spatial scales. Their interplay with magnetic fields is poorly characterized, however. Aims. We study the relation between a persistent photospheric vortex flow and the evolution of a network magnetic element at a supergranular vertex. Methods. We used long-duration sequences of continuum intensity images acquired with Hinode and the local correlation-tracking method to derive the horizontal photospheric flows. Supergranular cells are detected as large-scale divergence structures in the flow maps. At their vertices, and cospatial with network magnetic elements, the velocity flows converge on a central point. Results. One of these converging flows is observed as a vortex during the whole 24 h time series. It consists of three consecutive vortices that appear nearly at the same location. At their core, a network magnetic element is also detected. Its evolution is strongly correlated to that of the vortices. The magnetic feature is concentrated and evacuated when it is caught by the vortices and is weakened and fragmented after the whirls disappear. Conclusions. This evolutionary behavior supports the picture presented previously, where a small flux tube becomes stable when it is surrounded by a vortex flow.

scholarly journals Improving Habitat Quality at the Local and Landscape Scales Increases Wild Bee Assemblages and Associated Pollination Services in Apple Orchards in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Panlong Wu ◽  
Piaopiao Dai ◽  
Meina Wang ◽  
Sijie Feng ◽  
Aruhan Olhnuud ◽  
...  
Keyword(s):  
Management Practices ◽  
Ground Cover ◽  
Agricultural Landscapes ◽  
Wild Bees ◽  
Natural Habitats ◽  
Pollination Services ◽  
Wild Bee ◽  
Wide Range ◽  
Bee Diversity ◽  
Landscape Scales

Bees provide key pollination services for a wide range of crops. Accumulating evidence shows the effect of semi-natural habitats at the landscape level and local management practices on bee diversity in fields. However, most of the evidence is derived from studies in North America and Europe. Whether this paradigm is applicable in China, which is characterized by smallholder-dominated agricultural landscapes, has rarely been studied. In this study, we aimed to investigate how bee diversity affected apple production, and how landscape and local variables affected bee diversity and species composition on the Northern China Plain. The results showed that bees significantly increased apple fruit set compared to bagged controls. Wild bee diversity was positively related to apple seed numbers. Higher seed numbers reduced the proportion of deformed apples and thus increased fruit quality. Wild bee abundance was positively correlated with flowering ground cover, and both the abundance and species richness of wild bees were positively affected by the percentage of semi-natural habitats. We conclude that apple quality can benefit from ecological intensification comprising the augmentation of wild bees by semi-natural habitats and flowering ground cover. Future pollination management should therefore reduce the intensification level of management at both the local and landscape scales.

scholarly journals Rainfall spatio-temporal correlation and intermittency structure from micro-γ to meso-β scale in the Netherlands

2021 ◽  
Author(s):  
Thomas C. van Leth ◽  
Hidde Leijnse ◽  
Aart Overeem ◽  
Remko Uijlenhoet
Keyword(s):  
The Netherlands ◽  
Spatial Scales ◽  
Rainfall Variability ◽  
Temporal Structure ◽  
Temporal Correlation ◽  
Exponential Model ◽  
Rain Gauges ◽  
Wide Range ◽  
Spatio Temporal ◽  
Two Parameter

AbstractWe investigate the spatio-temporal structure of rainfall at spatial scales from 7m to over 200 km in the Netherlands. We used data from two networks of laser disdrometers with complementary interstation distances in two Dutch cities (comprising five and six disdrometers, respectively) and a Dutch nationwide network of 31 automatic rain gauges. The smallest aggregation interval for which raindrop size distributions were collected by the disdrometers was 30 s, while the automatic rain gauges provided 10-min rainfall sums. This study aims to supplement other micro-γ investigations (usually performed in the context of spatial rainfall variability within a weather radar pixel) with new data, while characterizing the correlation structure across an extended range of scales. To quantify the spatio-temporal variability, we employ a two-parameter exponential model fitted to the spatial correlograms and characterize the parameters of the model as a function of the temporal aggregation interval. This widely used method allows for a meaningful comparison with seven other studies across contrasting climatic settings all around the world. We also separately analyzed the intermittency of the rainfall observations. We show that a single parameterization, consisting of a two-parameter exponential spatial model as a function of interstation distance combined with a power-law model for decorrelation distance as a function of aggregation interval, can coherently describe rainfall variability (both spatial correlation and intermittency) across a wide range of scales. Limiting the range of scales to those typically found in micro-γ variability studies (including four of the seven studies to which we compare our results) skews the parameterization and reduces its applicability to larger scales.

scholarly journals Unique spatial integration in mouse primary visual cortex and higher visual areas

2019 ◽  
Author(s):  
Kevin A. Murgas ◽  
Ashley M. Wilson ◽  
Valerie Michael ◽  
Lindsey L. Glickfeld
Keyword(s):  
Visual Cortex ◽  
Visual System ◽  
Primary Visual Cortex ◽  
Spatial Information ◽  
Spatial Scales ◽  
Spatial Integration ◽  
Global Features ◽  
Wide Range ◽  
Visual Areas ◽  
Higher Visual Areas

AbstractNeurons in the visual system integrate over a wide range of spatial scales. This diversity is thought to enable both local and global computations. To understand how spatial information is encoded across the mouse visual system, we use two-photon imaging to measure receptive fields in primary visual cortex (V1) and three downstream higher visual areas (HVAs): LM (lateromedial), AL (anterolateral) and PM (posteromedial). We find significantly larger receptive field sizes and less surround suppression in PM than in V1 or the other HVAs. Unlike other visual features studied in this system, specialization of spatial integration in PM cannot be explained by specific projections from V1 to the HVAs. Instead, our data suggests that distinct connectivity within PM may support the area’s unique ability to encode global features of the visual scene, whereas V1, LM and AL may be more specialized for processing local features.

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