49 research outputs found
Annual Medicago spp. for WA rangelands - selection and establishment techniques
1) Exp 84KG1: Annual Medicago spp, for W.A. Rangeland. Ecotype testing with seeds sown (Woolibar Station). 2) Exp 84KG2: Pod seeding of annual Medics and response to phosphate fertilisation (I). (Woolibar Station). 3) Exp 84KG3: Serena Medics on Goldfield Rangeland - Pod seeding and pitting (Jeedamya Station). 4) Exp 84KG4: Pod seeding of annual Medics and response to phosphate fertilisation (II). (Woolibar Station). 5) Exp 84CA1: Establishment and survival of annual Medics - Pod seeding on W.A. rangelands simulating aerial seeding (Quobba Station). 6) Exp 84CA2: Annual Medicago spp. for W.A. rangeland - Ecotypes testing with seed sown (Hamelin Station). 7) Exp 84KG13: Assessment of vegetable matter contamination problems in greasy wool from pod samples of annual Medicago spp
Annual medics for the Kalgoorlie region and adjacent eastern rangeland zones
Species selection and establishment methods Extensive overgrazing and burning of the dominant winter rainfall Goldfields pastoral zones have left large areas degraded with a poor annual vegetation cover of nearly no grazing value. Thus, more grazing pressure is exerted on shrubs and small trees accelerating the desertification process. Shrubs and trees are the main stabilising agent left in a rangeland plant community when alI annuals have been grazed out. In order to upgrade or regenerate some of these areas, conventional methods of grazing prohibition or deferred grazing can be used but often, improvement obtained are slow. It is hypothesized that more active mean of rangeland regeneration combining the utilisation of appropriate annual legumes (nitrogen fixing plants) with sound establishment methods (micro water catchment techniques) and phosphate fertiIiser may greatly accelerate the recovery phase. Medicago species tested at Kalgoorlie and Carnarvon (1983). Experimental results from Kalgoorlie (83KG13), (83CA8) - annual medics for WA rangelands - sorted on descending order of POD Production (PODmgPROD). Programme for 1984. The extreme spread of our experimental sites (Kalgoorlie and Carnarvon) may be a limitant factor to our 1984 activities
Effects of habitat and livestock on nest productivity of the Asian houbara Chlamydotis macqueenii in Bukhara Province, Uzbekistan
To inform population support measures for the unsustainably hunted Asian houbara Chlamydotis macqueenii (IUCN Vulnerable) we examined potential habitat and land-use effects on nest productivity in the Kyzylkum Desert, Uzbekistan. We monitored 177 nests across different semi-arid shrub assemblages (clay-sand and salinity gradients) and a range of livestock densities (0–80 km-2). Nest success (mean 51.4%, 95% CI 42.4–60.4%) was similar across four years; predation caused 85% of those failures for which the cause was known, and only three nests were trampled by livestock. Nesting begins within a few weeks of arrival when food appears scarce, but later nests were more likely to fail owing to the emergence of a key predator, suggesting foraging conditions on wintering and passage sites may be important for nest productivity. Nest success was similar across three shrub assemblages and was unrelated to landscape rugosity, shrub frequency or livestock density, but was greater with taller mean shrub height (range 13–67 cm) within 50 m. Clutch size (mean = 3.2 eggs) and per-egg hatchability in successful nests (87.5%) did not differ with laying date, shrub assemblage or livestock density. We therefore found no evidence that livestock density reduced nest productivity across the range examined, while differing shrub assemblages appeared to offer similar habitat quality. Asian houbara appear well-adapted to a range of semi-desert habitats and tolerate moderate disturbance by pastoralism. No obvious in situ mitigation measures arise from these findings, leaving regulation and control as the key requirement to render hunting sustainable
Effects of habitat and land use on breeding season density of male Asian Houbara Chlamydotis macqueenii
Landscape-scale habitat and land-use influences on Asian Houbara Chlamydotis macqueenii (IUCN Vulnerable) remain unstudied, while estimating numbers of this cryptic, low-density, over-hunted species is challenging. In spring 2013, male houbara were recorded at 231 point counts, conducted twice, across a gradient of sheep density and shrub assemblages within 14,300 km² of the Kyzylkum Desert, Uzbekistan. Four sets of models related male abundance to: (1) vegetation structure (shrub height and substrate); (2) shrub assemblage; (3) shrub species composition (multidimensional scaling); (4) remote-sensed derived land-cover (GLOBCOVER, 4 variables). Each set also incorporated measures of landscape rugosity and sheep density. For each set, multi-model inference was applied to generalised linear mixed models of visit-specific counts that included important detectability covariates and point ID as a random effect. Vegetation structure received strongest support, followed by shrub species composition and shrub assemblage, with weakest support for the GLOBCOVER model set. Male houbara numbers were greater with lower mean shrub height, more gravel and flatter surfaces, but were unaffected by sheep density. Male density (mean 0.14 km-2, 95% CI, 0.12‒0.15) estimated by distance analysis differed substantially among shrub assemblages, being highest in vegetation dominated by Salsola rigida (0.22 [CI, 0.20‒0.25]), high in areas of S. arbuscula and Astragalus (0.14 [CI, 0.13‒0.16] and 0.15 [CI, 0.14‒0.17] respectively), lower (0.09 [CI, 0.08‒0.10]) in Artemisia and lowest (0.04 [CI, 0.04‒0.05]) in Calligonum. The study area was estimated to hold 1,824 males (CI: 1,645‒2,030). The spatial distribution of relative male houbara abundance, predicted from vegetation structure models, had the strongest correspondence with observed numbers in both model-calibration and the subsequent year’s data. We found no effect of pastoralism on male distribution but potential effects on nesting females are unknown. Density differences among shrub communities suggest extrapolation to estimate country- or range-wide population size must take account of vegetation composition
Breeding productivity, nest-site selection and conservation needs of the endemic Turkestan Ground-jay Podoces panderi
The Turkestan Ground-jay Podoces panderi, a corvid endemic to the deserts of Central Asia, is both understudied and under-protected. Using standardised nest-monitoring protocols and nest cameras, we estimated its breeding productivity for the first time as 0.586 fledglings per nesting attempt (inter-quartile range, IQR 0.413‒0.734), strongly constrained by a diverse set of predator species (accounting for 88% of failures), supporting the broad pattern that a wide spectrum of nest predators operate in arid environments. The probability of nest success for the 35 days from the start of incubation to fledging was low, 0.186 ± 0.06 se (N = 37), with no influence of season date, nest height or nest shrub species. However, pervasive shrub harvest severely limited availability of taller shrubs for nest-site selection, and thus our ability to detect any effect of height on nest survival. Mean clutch size was 4.8 ± 0.8 sd while hatching probability of an egg from a clutch surviving incubation was 0.800 ± 0.050 se and fledging probability was 0.824 ± 0.093 se for individual chicks in successful nests (i.e. that fledged one or more chicks). Two shrub genera, saxaul Haloxylon spp. and Calligonum spp., were used for nesting more frequently than expected (χ152 = 784.02, P < 0.001), highlighting their importance to breeding habitat suitability. This near-sole reliance on these taller shrub genera, both targeted for illegal cutting, indicates that habitat degradation may lead to increased predation and declines in productivity. Habitat conservation is, therefore, likely to be the most important management strategy for the species and other components of desert systems, as management of so diverse a set of nest predators would be both impractical and inappropriate
Prevalence and risk factors of helminths and intestinal protozoa infections among children from primary schools in western Tajikistan
BACKGROUND: Intestinal parasitic infections represent a public health problem in Tajikistan, but epidemiological evidence is scarce. The present study aimed at assessing the extent of helminths and intestinal protozoa infections among children of 10 schools in four districts of Tajikistan, and to make recommendations for control.
METHODS: A cross-sectional survey was carried out in early 2009. All children attending grades 2 and 3 (aged 7-11 years) from 10 randomly selected schools were invited to provide a stool sample and interviewed about sanitary situation and hygiene behaviour. A questionnaire pertaining to demographic and socioeconomic characteristics was addressed to the heads of households. On the spot, stool samples were subjected to duplicate Kato-Katz thick smear examination for helminth diagnosis. Additionally, 1-2 g of stool was fixed in sodium acetate-acetic acid formalin, transferred to a specialized laboratory in Europe and examined for helminths and intestinal protozoa. The results from both methods combined served as diagnostic 'gold' standard.
RESULTS: Out of 623 registered children, 602 participated in our survey. The overall prevalence of infection with helminths and pathogenic intestinal protozoa was 32.0% and 47.1%, respectively. There was pronounced spatial heterogeneity. The most common helminth species was Hymenolepis nana (25.8%), whereas the prevalences of Ascaris lumbricoides, hookworm and Enterobius vermicularis were below 5%. The prevalence of pathogenic intestinal protozoa, namely Giardia intestinalis and Entamoeba histolytica/E. dispar was 26.4% and 25.9%, respectively. Almost half of the households draw drinking water from unimproved sources, such as irrigation canals, rivers and unprotected wells. Sanitary facilities were pit latrines, mostly private, and a few shared with neighbours. The use of public tap/standpipe as a source of drinking water emerged as a protective factor for G. intestinalis infection. Protecte spring water reduced the risk of infection with E. histolytica/E. dispar and H. nana.
CONCLUSIONS: Our data obtained from the ecological 'lowland' areas in western Tajikistan call for school-based deworming (recommended drugs: albendazole and metronidazole), combined with hygiene promotion and improved sanitation. Further investigations are needed to determine whether H. nana represents a public health problem
Annual Medicago spp. for WA rangelands - selection and establishment techniques
1) Exp 84KG1: Annual Medicago spp, for W.A. Rangeland. Ecotype testing with seeds sown (Woolibar Station). 2) Exp 84KG2: Pod seeding of annual Medics and response to phosphate fertilisation (I). (Woolibar Station). 3) Exp 84KG3: Serena Medics on Goldfield Rangeland - Pod seeding and pitting (Jeedamya Station). 4) Exp 84KG4: Pod seeding of annual Medics and response to phosphate fertilisation (II). (Woolibar Station). 5) Exp 84CA1: Establishment and survival of annual Medics - Pod seeding on W.A. rangelands simulating aerial seeding (Quobba Station). 6) Exp 84CA2: Annual Medicago spp. for W.A. rangeland - Ecotypes testing with seed sown (Hamelin Station). 7) Exp 84KG13: Assessment of vegetable matter contamination problems in greasy wool from pod samples of annual Medicago spp
Annual medics for the Kalgoorlie region and adjacent eastern rangeland zones
Species selection and establishment methods Extensive overgrazing and burning of the dominant winter rainfall Goldfields pastoral zones have left large areas degraded with a poor annual vegetation cover of nearly no grazing value. Thus, more grazing pressure is exerted on shrubs and small trees accelerating the desertification process. Shrubs and trees are the main stabilising agent left in a rangeland plant community when alI annuals have been grazed out. In order to upgrade or regenerate some of these areas, conventional methods of grazing prohibition or deferred grazing can be used but often, improvement obtained are slow. It is hypothesized that more active mean of rangeland regeneration combining the utilisation of appropriate annual legumes (nitrogen fixing plants) with sound establishment methods (micro water catchment techniques) and phosphate fertiIiser may greatly accelerate the recovery phase. Medicago species tested at Kalgoorlie and Carnarvon (1983). Experimental results from Kalgoorlie (83KG13), (83CA8) - annual medics for WA rangelands - sorted on descending order of POD Production (PODmgPROD). Programme for 1984. The extreme spread of our experimental sites (Kalgoorlie and Carnarvon) may be a limitant factor to our 1984 activities
Dégradation et restauration: réhabilitation des parcours des zones semi-arides et arides. Fiction ou réalité?
*INRA, Documentation, Montpellier (FRA) Diffusion du document : INRA, Documentation, Montpellier (FRA)National audienc