Winter durability of pygmy bluetongue lizard burrows is higher for occupied than for unoccupied burrows and for those in less-grazed neighbourhoods

2016 ◽  
Vol 43 (8) ◽  
pp. 634 ◽  
Author(s):  
Torben P. Nielsen ◽  
C. Michael Bull
Keyword(s):  
Direct Effect ◽  
Vegetation Cover ◽  
Soil Structure ◽  
South Australia ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Sheep Grazing ◽  
Native Grassland ◽  
Burrow Entrance ◽  
Different Levels

Context Many ectothermic animals survive winter by hibernating, either buried or in burrows. During their hibernation these animals are vulnerable to changes in soil structure and temperature caused by the activity of grazing mammals. This may be a particular risk to ectotherms living in native grassland, as this habitat is often used for livestock grazing. The endangered pygmy bluetongue lizard lives in burrows, in fragments of native grassland in South Australia, and these burrows are likely to be affected by sheep grazing during the lizards’ hibernation. Aims The current study aimed to determine the following effects on the persistence of burrows suitable to the pygmy bluetongue lizard: different levels of grazing, winter vegetation cover, burrow entrance size and whether a lizard was overwintering in the burrow. Methods During two winters, we applied different grazing treatments to six experimental paddocks and determined whether suitable lizard burrows located in autumn were still suitable to lizards in the following spring. For each burrow, we recorded whether a lizard was overwintering, the burrow entrance diameter and the vegetation cover around the burrow during the winter. Key results Increased grazing pressure led to decreased persistence of lizard burrows. We also found that burrows with an overwintering lizard had a greater chance of persisting, but found no direct effect of winter vegetation cover or entrance diameter. Conclusions The results show that although pygmy bluetongue lizards may be able to stabilise their own burrows, the more intense the grazing the lower the chance of lizard burrow persistence. Implications Management of sheep grazing is an important component in future conservation of the endangered pygmy bluetongue lizard. Grazing on grassland with a lizard population should be kept at a moderate level and hard grazing should be avoided.

Rangeland responses to pastoralists' grazing management on a Tibetan steppe grassland, Qinghai Province, China

2016 ◽  
Vol 38 (1) ◽  
pp. 1 ◽  
Author(s):  
Richard B. Harris ◽  
Leah H. Samberg ◽  
Emily T. Yeh ◽  
Andrew T. Smith ◽  
Wang Wenying ◽  
...  
Keyword(s):  
Plant Species ◽  
Temporal Trends ◽  
Winter Season ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Western China ◽  
Permanent Plots ◽  
Sheep Grazing ◽  
Qinghai Province ◽  
Preferred Species

Livestock grazing is the principal land use in arid central Asia, and range degradation is considered a serious problem within much of the high-elevation region of western China termed the Qinghai-Tibetan Plateau (QTP). Rangeland degradation on the QTP is variously attributed to poor livestock management, historical-cultural factors, changing land tenure arrangements or socioeconomic systems, climate change, and damage from small mammals. Few studies have examined currently managed pastures using detailed data capable of isolating fine-scale livestock–vegetation interactions. The aim of the study was to understand how differences among livestock (primarily sheep) management strategies of pastoralists during winter affected subsequent rangeland condition and productivity. Plant species composition, annual herbage mass, and indicators of erosion were quantified during four summers (2009–2012) on winter pastures managed by 11 different pastoralists on QTP steppe rangeland in Qinghai Province, China. Data came from repeated-measurements on 317 systematically located permanent plots, as well as pastoralist interviews and the use of GPS-equipped livestock. Relationships between annual weather variation and herbage mass were modelled using an independent set of vegetation measurements obtained from livestock exclosures. Account was taken of inherent site differences among pastures. Annual variation in herbage mass was found to be best fitted by a model containing a negative function of winter-season temperature and a positive function of spring-season temperature. Accounting for annual and site effects, significant differences among pastoralists were found for most response variables, suggesting that individual heterogeneity among management approaches had consequences, even among neighbouring pastoralists. Annual herbage mass of preferred plant species was positively associated, whereas that of unpreferred species was negatively associated, with mean sheep density and intensity of use. However, the proportion of bare soil, an index of erosion, and annual herbage mass of unpreferred forbs were found to have positive relationships with sheep grazing pressure during the preceding winter, whereas live vegetation cover and annual herbage mass of preferred grasses were negatively related. Thus, on a spatial scale, pastoralists responded adaptively to the cover of preferred plant species while not responding to total annual herbage mass. Pastoralists stocked pastures more heavily, and livestock used regions within pastures more intensively, where preferred species had a higher cover. However, where sheep grazing pressure was high, downward temporal trends in the herbage mass of preferred species were exacerbated. Pastures that were stocked at a lower density did not experience the negative trends seen in those with a higher density.

Estimation of the Density of Feral Goats in Part of Arid South Australia by means of the Peterson Estimate

1984 ◽  
Vol 11 (1) ◽  
pp. 93 ◽  
Author(s):  
RP Henzell ◽  
PI McCloud
Keyword(s):  
South Australia ◽  
Grazing Pressure ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Arid Rangeland

The density of feral goats in about 234 km2 of arid rangeland used for sheep grazing in South Australia was estimated by means of a mark-resight technique. Marking and subsequent resighting were done at watering points. The Petersen estimate was 4.4 goats per square kilometre; adjustment to allow for nonrandom behaviour raised this estimate to 5.0 km-1. Maximum allowable sheep density is 12 km-2. The goat density we observed imposes an added burden on the vegetation. The densities of red and western grey kangaroos, when added together, approximate that of the goats. Rabbits are virtually absent. The long-term effects of the total grazing pressure on the vegetation cannot be predicted in detail but will probably be deleterious.

scholarly journals Fly family diversity shows evidence of livestock grazing pressure in Mongolia (Insecta: Diptera)

2018 ◽  
Vol 22 (2) ◽  
pp. 231-243 ◽  
Author(s):  
Rebecca A. Clement ◽  
Paul B. Frandsen ◽  
Tristan McKnight ◽  
C. Riley Nelson
Keyword(s):  
Grazing Pressure ◽  
Livestock Grazing ◽  
Family Diversity

The impact of sheep grazing on the depth of spider burrows and of burrows selected by the pygmy bluetongue lizard (Tiliqua adelaidensis)

2016 ◽  
Vol 43 (8) ◽  
pp. 691 ◽  
Author(s):  
Jessica Clayton ◽  
Michael Bull
Keyword(s):  
Endangered Species ◽  
South Australia ◽  
Sheep Grazing ◽  
Vegetative Cover ◽  
Austral Spring ◽  
Essential Component ◽  
Grazing Sheep ◽  
Essential Resource ◽  
The Impact ◽  
Domestic Stock

Context Grazing by domestic stock can potentially influence ecosystems positively or negatively, depending on the grazing regime and intensity. The pygmy bluetongue lizard (Tiliqua adelaidensis) is an endangered species, restricted to fragmented grasslands in the Mid North region of South Australia, predominantly grazed by sheep. These lizards refuge in vertical burrows. They do not dig their own burrows, instead relying on co-existing spiders for this essential resource. Aims We investigated how sheep grazing influenced spider burrows, and predicted the following: that grazing sheep might trample and destroy shallow burrows; that burrows in grazed habitat with less vegetative cover would have higher temperatures in summer; and that, by way of compensation, spiders would dig deeper burrows in grazed habitat. Methods We monitored 12 30m×30m plots monthly, over two austral spring/summer periods (September–March 2012–14). We recorded the number, depth and occupant of all spider burrows in those plots in each survey. We also measured temperatures inside artificial burrows in grazed and ungrazed habitat over a 3-day period in September 2014. Key results Mean burrow depth increased with grazing. This was not because individual burrows became deeper, but because the shallowest burrows were lost where there were sheep. Burrows were significantly hotter in grazed habitat, but lizards consistently chose deeper, cooler burrows. In the subset of burrows that were occupied by lizards, there was no difference in depth between grazed and ungrazed treatments. We detected no difference in spider digging activity between grazed and ungrazed plots. Conclusions Sheep grazing can destroy shallow burrows, probably through trampling, and because sheep produce burrow filling debris. However, grazing did not affect deeper burrows occupied by pygmy bluetongue lizards. Implications This short study indicated that moderate levels of grazing have low impact on deeper burrows suitable for pygmy bluetongue lizards and for lizard persistence. It explains how sheep and lizards have co-occurred for so long, but leaves open the question of how the loss of shallow burrows affects populations of the burrow-digging spiders that are an essential component of the lizard environment.

Herbage mass thresholds rather than plant phenology are a more useful cue for grazing management decisions in the mid-north region of South Australia

2010 ◽  
Vol 32 (4) ◽  
pp. 379 ◽  
Author(s):  
Lewis P. Kahn ◽  
Judi M. Earl ◽  
Millie Nicholls
Keyword(s):  
Perennial Grass ◽  
South Australia ◽  
Plant Phenology ◽  
Perennial Grasses ◽  
Grazing Management ◽  
Plant Production ◽  
Sheep Grazing ◽  
Management Decisions ◽  
Basal Cover ◽  
Seasonal Grazing

Research was conducted in the mid-north of South Australia over the period 2000–05 to evaluate the effects of different grazing management cues on composition and production of a grassland. The management cues were based on calendar, plant phenology or herbage mass thresholds using grazing exclusion as a control. There were five grazing treatments: (i) regional practice (RP), where sheep grazed continuously for the period April–December; (ii) autumn rest, where sheep grazing was restricted to June–December; (iii) spring rest, where sheep grazing was restricted to April–August; (iv) high density and short duration (HDSD), where herbage mass thresholds determined when grazing occurred and for what duration; and (v) nil (NIL) grazing by domestic herbivores. Mean annual estimates of herbage mass were highest for NIL and HDSD and inclusion of the estimate of herbage consumption by sheep resulted in greatest primary plant production in HDSD. The contribution of perennial grasses to herbage mass declined with RP and seasonal grazing treatments. Frequency of perennial grasses was unaffected by grazing treatment but the number of perennial grass plants increased over time in RP and seasonal treatments. HDSD allowed maintenance of basal cover whereas bare ground increased with RP and seasonal treatments. Litter accumulated in NIL but this was associated with a decline in perennial basal cover. Seasonal grazing treatments did not provide an advantage over RP and there appeared to be no benefit from including phenology in management decisions. In contrast, HDSD resulted in a stable and productive grassland ecosystem, with stocking rate estimated at 78% greater than other treatments. These features offer a desirable mix for future industry adoption in the mid-north of South Australia.

Grazing Gradients in Central Australian Rangelands: Ground Verification of Remote Sensing-Based Approaches.

1993 ◽  
Vol 15 (2) ◽  
pp. 217 ◽  
Author(s):  
GN Bastin ◽  
AD Sparrow ◽  
G Pearce
Keyword(s):  
Satellite Data ◽  
Vegetation Cover ◽  
Field Data ◽  
Graphical Representation ◽  
Woody Species ◽  
Soil Surface ◽  
Grazing Pressure ◽  
Remotely Sensed Data ◽  
Suitable Technique ◽  
Grazing Behaviour

Remotely-sensed data collected by satellites have been proposed for investigating grazing effects across the large paddocks of arid Australia. These data are used to compute indices of vegetation cover which are then analysed with reference to patterns of grazing behaviour around watering points. Grazing pressure typically increases as water is approached, resulting in a decrease in herbage cover. This pattern of cover change is called a grazing gradient. The change in these gradients from a dry to wet period forms the basis for assessing land degradation as described in an accompanying paper. This study demonstrates that grazing gradients do exist, that they can be detected with field-based methods of data collection, and that there is close correspondence between ground data and indices of vegetation cover obtained from contemporary Landsat Multispectral Scanner satellite data. Field data representing aerial cover of the herbage and woody species layers were collected along transects radiating away from water at two sites grazed by cattle in central Australia. Graphical representation of the litter and herbage components demonstrate that gradients of decreasing cover attributable to increasing grazing pressure occur along all, or sections, of each transect. Highly significant correlations exist between the field data and satellite indices of vegetation cover. Localised shrub increase and patches of recent erosion obscured trends of increasing cover with distance from water on parts of some transects. Soil surface state (describing past erosion) was a significant covariate of cover change at one site. Our ability to characterise gradients of increasing vegetation cover with distance from water using both field and satellite data should mean that the grazing gradient method, when used with satellite data, is a suitable technique for assessing the extent of landscape recovery following good rainfall.

The influence of plant diversity on the resilience of harvester termites to fire

1995 ◽  
Vol 2 (3) ◽  
pp. 279 ◽  
Author(s):  
Max Abensperg-Traun ◽  
Dion Steven ◽  
Lyn Atkins
Keyword(s):  
Western Australia ◽  
High Intensity ◽  
Experimental Studies ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Floristic Diversity ◽  
Long Term Effects ◽  
Burnt Area ◽  
Food Species

The harvester termites in floristically rich mallee-heath of southern Western Australia appear resilient to high-intensity fire. This contrasts with the temporary extinction of harvesters occupying a narrow food niche in floristically simple, intensely burnt spinifex Triodia angusta grassland in tropical Western Australia. The present study examines the effects of high-intensity fire on harvester termites Drepanotermes tamminensis in vegetation of intermediate floristic diversity and compares its findings with these earlier studies. We sampled 20 mounds (termitaria) in both an unburnt and (adjacent) burnt stand of Allocasuarina campestris shrubland. Although partially regenerated three years after the fire, 40% of mounds in the burnt area were abandoned, contrasting with 10% in the unburnt stand. No harvested chaff was found in any of the abandoned mounds. The extent of mound occupation by D. tamminensis was considerably lower, and ant invasion higher, in the burnt stand. These findings are consistent with the hypothesis that high floristic diversity enhances the resilience of harvester termites to fire. The most likely mechanism is the availability of a range of plant (food) species with different regenerative responses to high-intensity fire. The death of spinifex and the associated harvester termites after fire may be atypical. We argue, however, that temporary extinction of harvester populations in arid Australia may not be exceptional, particularly where fire coincides with drought and high livestock grazing pressure. Rigorous experimental studies are necessary to enhance our understanding of the long-term effects of fire on harvester termite populations in different vegetation types and climatic zones.

From the results of the stability of soil structure studies and the physical characteristics of the black meadow soil of the mountain meadow in the limited national park (gorkhi-terelj national park)

2018 ◽  
Vol 22 (03) ◽  
pp. 89-95
Author(s):  
Lkhamsuren B ◽  
Odgerel B ◽  
Purevsuren Sh
Keyword(s):  
Physical Properties ◽  
Vegetation Cover ◽  
National Park ◽  
Soil Structure ◽  
Soil Stabilization ◽  
Meadow Soil ◽  
Mountain Meadow ◽  
Stability And Stabilization ◽  
The Stability ◽  
Properties Of Soil

The study aims to investigate changes in the physical properties of soil depending on the utilization conditions of the Special Protected National Park compared to the area fenced for more than 10 years. The stability and stabilization of the stabilized mountain meadow soil stabilization and physical properties of soil in the Gorkhi-Terelj National Park (GTNP) resort and limited concentration of tourism. As a result of the study, the stability of the soil structure was 2.8 points in the area of vegetation cover 0-3 cm outside the fence, while the 2.6 layered soil layers above the soils of the vegetation cover. However, the area with vegetation cover within the fence is 4.2 points in soil 0-3 cm and 4 leaves in soil without vegetation cover.

scholarly journals Impacts of grazing on vegetation dynamics in a sediment transport complex model

2020 ◽  
Author(s):  
Phillipe Gauvin-Bourdon ◽  
James King ◽  
Liliana Perez
Keyword(s):  
Sediment Transport ◽  
Vegetation Cover ◽  
Current Knowledge ◽  
Dynamic Balance ◽  
Grazing Pressure ◽  
Complex Model ◽  
Arid Environments ◽  
Agent Based ◽  
The Stability ◽  
Transport Complex

Abstract. Arid environments are characterized by the complex interaction between vegetation cover, surface soil properties, and the climate. The dynamic balance between these components makes arid environments highly susceptible to swift changes in vegetation cover and in surface morphology in response to climate change. Furthermore, arid environments often support grazing activities, which influence other ecogeomorphic processes and alter the stability of vegetation cover in these environments. Despite the growing knowledge and the parallel modelling advances to simulate the sediment transport, vegetation distribution, and grazing, in arid environments, relatively little progress has been accomplished on the interaction between all these components in combination. Here we present an adaptation of an already established sediment transport-vegetation cellular automata model (Vegetation and Sediment TrAnsport or ViSTA) that represents landscape dynamics, with an agent-based model (GrAM) representing the activity of grazers on the landscape. In this study our resulting model, ViSTA_GrAM, is subjected to a series of 100-year long tests that aim to highlight the capacity of the model to represent ecogeomorphic processes linked to vegetation composition, rainfall, windspeed, and grazing pressure. The new model provides an improved representation of the feedback complexities between grazers and the vegetation, in addition to providing insight on the vegetation and wind shear sensitivity of the original model. The simulations reinforce our current knowledge on the resilience of grass-based landscapes to foraging activities and highlights the need to identify growth response rates at the species level to fully understand the complexity of the interactions between individual components within arid environments. Overall, the ViSTA_GrAM model represents an important improvement for managing arid landscapes over the previously available tools.

scholarly journals EVALUATION OF TOURISM POTENTIAL IN DOGANKENT DISTRICT IN GIRESUN

2015 ◽  
pp. 400-409
Keyword(s):  
Cultural Values ◽  
Significant Relationship ◽  
Human Activities ◽  
Vegetation Cover ◽  
Soil Structure ◽  
Field Surveys ◽  
Tourism Potential ◽  
Different Cultures ◽  
Natural Characteristics ◽  
East Anatolia

Tourism is defined to be the combination of events and relationships resulting from the travels and accommodation for temporary human activities lasting from at least two days to two years with the aims of performing activities like work, recreation, entertainment, experiencing different cultures and living styles and sport. There is absolutely a significant relationship between tourism and natural-cultural source values. Tourism can gain a shape in an area depending largely on natural and cultural source values there. Turkey has multi-form and colored landscape diversity changing from city to city and region to region due to its natural characteristics like vegetation cover, climate, topography and soil structure and its cultural richness caused by the factors such as traditions and customs, folkloric and settlement features. Color and form offered by the landscape in Blacksea region change into different colors and forms in East Anatolia and Aegean regions. Such diversity in landscape can offer possibility for also tourism. In the present study, the district of Doğankent in the province of Giresun located in Blacksea region is evaluated. In the scope of the study, surveys were conducted in study area between 2011 and 2014 and natural and cultural values tried to be evaluated. It was determined according to the field surveys on natural and cultural reserves of Doğankent that the area may offer important opportunities for culture, gastronomy, flora, winter, nature and 3 plateau tourism and should be evaluated for these tourism types.

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