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Is what you see what you get? Visual vs. measured assessments of vegetation condition

  • Authors: Cook, Carly , Wardell-Johnson, Grant , Keatley, Marie , Gowans, Stacey , Gibson, Matthew , Westbrooke, Martin , Marshall, Dustin
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Journal of Applied Ecology Vol. 47, no. 3 (2010), p. 650-661
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  • Description: 1. An important step in the conservation of biodiversity is to identify what exists, its quantity and its quality (i.e. condition). This can be a daunting task at the landscape-scale, so vegetation communities are often used as surrogates for biodiversity. Satellite imagery has improved our ability to rapidly measure vegetation parameters but the need for calibration still requires rapid and cost-effective on-ground condition assessment. Some management agencies address this need by using visual condition assessments, with unknown consequences for the different purposes of condition data. It is therefore vital to examine the comparability of visual and systematic condition assessment methods to guide their use in conservation decision making. 2. We compared visual assessments of vegetation condition with more systematic and higher resolution on-ground assessments, using a method where both assessments were made for the same quadrats. We determined both the condition parameters observers respond to when making visual assessments of condition, and the consequences of any differences for the application of these data. 3. We found that visual assessment of vegetation condition broadly represented measured assessments of the same vegetation, but that observers simplify their assessments by responding to only some of the measured condition parameters. No consistent trends were found in the parameters observers responded to across the different vegetation types sampled. 4. Synthesis and applications. We conclude that visual estimates of vegetation condition are only of sufficient resolution to replace more expensive, high-resolution assessments at a landscape-scale, when condition results are combined over multiple areas and vegetation types. Visual assessment methods potentially can provide an efficient measure of overall condition for conservation management agencies where practitioners can make assessments of condition in the course of their daily management activities - an important step forward. At smaller scales, idiosyncratic effects render visual estimates highly variable when compared with systematic condition assessments. This variability, especially among vegetation types, suggests that more systematic assessments are necessary when management decisions require higher-resolution estimates of changes in individual condition parameters, such as when measuring the success of individual management actions. These findings provide a valuable guide for selecting the most appropriate approach for the different objectives of condition assessments for biodiversity conservation.
  • Description: 2003008171

Invasion of the noxious weed Nicotiana glauca R. Graham after an episodic flooding event in the arid zone of Australia

  • Authors: Florentine, Singarayer , Westbrooke, Martin
  • Date: 2005
  • Type: Text , Journal article
  • Relation: Journal of Arid Environments Vol. 60, no. 4 (Mar 2005), p. 531-545
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  • Description: During November 1997, an extreme rainfall event caused flooding in the Olary Creek and created a terminal lake within mallee vegetation on Nagaela Station, far western New South Wales. To assess the effect of this rare event on native flora, six 25×25 m2 grazing exclusion plots were established on flooded (4), and un-flooded control (2) areas. We investigated (i) the distribution of Nicotiana glauca in relation to the 1997 flooding event (ii) the variation in density of N. glauca soil-stored seed between soil in control and exclosure plots (iii) the allelopathic effects of N. glauca on germination of Lactuca sativa seeds. Analysis of N. glauca stem sections revealed a maximum of five growth rings, confirming an origin following the 1997 flood event. At a September 1998 assessment, no N. glauca were found across flooded and control plots. In October 2000 N. glauca occurred at densities of 24 and 12 N. glauca seedlings ha−1 in the flooded unfenced and fenced plots respectively. No N. glauca individuals were recorded either from control fenced or unfenced plots. The soil-stored seed study revealed that larger numbers of N. glauca seeds were recovered from the flooded open plot (1936±968) than in flooded fenced plots (856±428.12) but none was found in the control plots. Leachates obtained from dry leaves and twigs had a significantly greater negative impact (p>0.001) on germination of L. sativa seeds than leachates obtained from fresh leaves and bark. This study showed that the density of N. glauca is high in areas where grazing had eliminated competition from native shrubs and grasses. N. glauca is potentially a serious weed along the Olary Creek and ephemeral lake boundaries. Management strategies such as reducing grazing pressure from native and introduced animals and/or effective eradication programs should be adopted, to minimize further infestation.
  • Description: C1
  • Description: 2003001049

Fire and hollow formation in box-ironbark eucalypts of the Warby Range State Park

  • Authors: Adkins, Matthew , Westbrooke, Martin , Florentine, Singarayer , McDonald, Simon
  • Date: 2005
  • Type: Text , Journal article
  • Relation: Victorian Naturalist Vol. 122, no. 1 (2005), p. 47-56
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  • Description: Hollows are an important, but rare, resource for several native vertebrate species in the box-ironbark forests of central Victoria. A study assessed the external features of trees from burnt and unburnt areas of forest to determine the influence of fire on hollow formation in these forests. Significantly greater proportions of trees in burnt areas has scars than trees in unburnt areas. Fire had less influence on the number of small, medium, large and very large dead branches/branch stubs than tree diameter. Similarly, tree size rather than fire was a major determinant in the occurrence of hollows. The greater number of scars in burnt trees might eventually lead to a difference in hollow numbers between burnt and unburnt trees (A).
  • Description: 2003001062

Responses of the weed parthenium hysterophorus (Asteraceae) to the stem Gall-inducing Weevil Conotrachelus albocinereus (Coleoptera: Curculionidae)

  • Authors: Florentine, Singarayer , Westbrooke, Martin , Dhileepan, Kunjithapatham
  • Date: 2002
  • Type: Text , Journal article
  • Relation: Entomologia Generalis Vol. 26, no. 3 (2002), p. 195-206
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  • Description: A slem-galling weevil COT/o/rad,e/us alboeinereus Fiedler 1940 from Argentina is being field released to regulate populations of the weed Parlhenium hysterophorus in Queensland, Australia since 1995. In this paper we report the tissue and metabolic responses in P hyslerophorus in the context of the biology and feeding behaviour of the weevil. C albocinereus induces elliptical galls often on the main shoot axes and rarely on the terminal and axillary mcristems of the host plant. From oviposition through gall maturation, the structure and metabolism of the host-plant tissues. especially at the gall region, change continuously to accommodate pressure inflicted by the feeding larva. The host plant shows re-dirtttion of its vital metabolites to the gall, and to the lTlCtaplasitd cells of nutrition in particular. In mature galls. the pith parenchyma elements tum lignified. Larval feeding fractures the vertical continuity of vascular tissues, which affects the host plant's overall metabolism As the larva tunnels the shoot eolulTVl. it places the frass at the fissured vascular sites. That activity initialcs n«rosis and eventual death of the living eells of the vascular tissue complex. Such a development induces water.logging stress in the gall and the evapotranspirauonal system displays contrasting responses. Pennanenl1y closed Siomatal apertures and abnonnally inflated substomatal chambers indicate that P hYSleropltorus suffers moisture-stress with cecidogenesis. The larval performance triggers moisture inundation in the galled shoot and this appears to be an advantage in using this weevil in the control of P hyslerop/rorus.
  • Description: C1
  • Description: 2003004175

Arid land vegetation dynamics after a rare flooding event : influence of fire and grazing

  • Authors: Westbrooke, Martin , Florentine, Singarayer , Milberg, Per
  • Date: 2005
  • Type: Text , Journal article
  • Relation: Journal of Arid Environments Vol. 61, no. 2 (Apr 2005), p. 249-260
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  • Description: Arid vegetation is subjected to more or less frequent fire, drought, and sporadic flooding events and grazing. Whilst fire, drought and grazing have been the subject of considerable research, little is known of the impact of flooding in arid environments. In this study we examined opportunistically the effects of a flooding event, and its interaction with fire and grazing on moulding arid vegetation in New South Wales, Australia. We assessed vegetation approximately 2 and 5 years after recession of the water in fenced and unfenced plots subjected to different combinations of flooding and fire. Number of species per area dropped from 11.8 to 5.7 per 625 m(2). Vegetation in plots left open to grazing by vertebrates differed from fenced plots, but the amount of variation explained was small compared with flooding and the change over time. The taxa mostly associated with flooding were Eragrostis spp., Pseudognaphalium luteoalbum and the exotic Nicotiana glauca. Major flooding events not only trigger native species' germination and recruitment but may also create an avenue for exotic species to invade. (C) 2004 Elsevier Ltd. All rights reserved.
  • Description: C1
  • Description: 2003001050

Flowering, fruiting, germination and seed despersal of the newly emerging weed Solanum mauritianum Scop. (solanaceae) in the wet tropics of north Queensland

  • Authors: Florentine, Singarayer , Westbrooke, Martin , Craig, M.
  • Date: 2003
  • Type: Text , Journal article
  • Relation: Plant Protection Quarterly Vol. 18, no. 3 (2003), p. 116-120
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  • Description: Solanum mauritianum (wild tobacco) has recently become a weed of major concern in some agricultural production areas, and tropical rainforest restoration sites, of the Atherton Tablelands, north Queensland. Until recently, little was known about the ecology of this species. A study was conducted to examine: Ii) the flowering, fruiting pattern, (ii) seed germination pattern, (iii) density of soil stored seed bank, and (iv) potential avian seed dispersers of S. mauritianum. Flowering and fruiting patterns were studied on-randomly selected plants within the study site over a period of 35 days. A germination study was performed on green (unripe) and yellow (ripe) fruits with seeds from green fruits germinating faster than seeds collected from yellow fruits. The density of genninable seeds in the soil seed bank was determined from 94 samples collected beneath the canopy of 24 randomly selected S. mauritianum plants. Of seedlings Ihat germinated, 73% were S. mauritianum and seedling density of S. mauritiallum averaged 16 000 seedlings per hectare. To determine the role of birds in the dispersal of S. mauritianum seeds, observations were made of all birds visiting eleven fruit-bearing plants. To examine the bird's excrement, birds were captured in mist-nets, their excrement collected and any seeds present identified. A total of 340 seeds from 15 plant species were obtained. Four tropical rainforest birds (Australian king parrots (
  • Description: C1
  • Description: 2003000548

Evaluation of alternative approaches to rainforest restoration on abandoned pasturelands in tropical north Queensland, Australia

  • Authors: Florentine, Singarayer , Westbrooke, Martin
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Land Degradation & Development Vol. 15, no. 1 (Jan-Feb 2004), p. 1-13
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  • Description: The lag time for natural recruitment of tropical rainforest species in abandoned pastureland is very long, therefore artificial restoration techniques have been employed to accelerate natural seedling recruitment. The objectives of this study were to investigate: (1) the success/failure of establishment 502 seedlings belonging to 15 species from 11 families planted approximately ten years ago; and (2) the influence of different restoration techniques on enhancing natural recruitment during this period. The study was conducted in the wet tropical rainforest region of northeast Queensland, Australia as a completely randomized block design involving five treatments with two replicates. In each plot, 63 tropical rainforest seedlings from one or a combination of species were planted randomly. Two control plots were laid out where no seedlings were planted. Survival, height and diameter data were taken on the seedlings ten years after planting. Each 11×17 m2 plot was further divided into 187, 1×1 m2 subplots. Within each subplot all seedlings recruited were located and identified. Canopy cover was estimated using belt transects 1 m apart that ran in an east-west direction across the plots. Within each plot the percentage of grass, and the crown cover were estimated using the Braun-Blanquet cover abundance scale. Survival rate of planted seedlings varied across the treatment plots. The survival rate ranged from 65 to 75 per cent for primary-promoter species, 85 to 100 per cent in middle-phase species and 42 to 57 per cent for mature-phase species. No Pilidiostigma tropicum seedlings survived in any treatment. Fourteen species recruited naturally across the treatment plots. A total of 410 seedlings were naturally recruited from 11 different families in the ten-year-old reforested site. The highest natural recruitment (236 seedlings) occurred in Treatment 3, where Omalanthus novo-guineensis seedlings were planted with eight primary-promoter species, followed by 99 in Treatment 5 where a group of primary-promoters, middle phase species and mature-phase species were planted together, 36 in Treatment 4 (Alphitonia petriei planted with eight primary-promoter species), 10 in Treatment 2 where only Omalanthus novo-guineensis seedlings were planted, and 13 in control plots. Grass cover declined with increasing species diversity and increased canopy cover. The results indicate that the diversity of species used in restoration had a major influence on natural recruitment. Copyright © 2004 John Wiley & Sons, Ltd.
  • Description: C1
  • Description: 2003000714

Macroinvertebrate communities in Phragmites australis (Cav.) Trin. ex Steud. reed beds and open bank habitats in central Victorian streams in Australia

  • Authors: Jayawardana, Chandamali , Westbrooke, Martin , Wilson, Michael , Hurst, Cameron
  • Date: 2006
  • Type: Text , Journal article
  • Relation: Hydrobiologia Vol. 568, no. 1 (2006), p. 169-185
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  • Description: Reed invasion is a common phenomenon of open streams with disturbed riparian vegetation in river catchments. Knowledge of the effects of such vegetation change on aquatic communities is fundamental to river management. Macroinvertebrate fauna in Phragmites australis (Cav.) Trin. ex Steud. and open bank habitats were examined in three rivers in central Victoria in order to understand the effect of such littoral habitat on macroinvertebrates. Data were analysed using Partially Nested Factorial ANOVA with season, river and habitats as main effects. Habitat structure had a significant effect (p < 0.05) on macroinvertebrate species richness, however this was not seasonally consistent across the three rivers. There was a significant increase (p < 0.05) in macroinvertebrate taxa richness in Phragmites habitats during winter and spring seasons. Total abundance of taxa showed no consistent significant differences in the two habitats. Results of Canonical Analysis of Principle Coordinates indicated significant differences (p < 0.05) in macroinvertebrate assemblages between Phragmites and bare bank habitats in all seasons. Habitat selection by taxa could be related to the microphysical environment of the habitats. This study suggests that reed beds create important littoral habitat structures which support diverse macroinvertebrate assemblages. © Springer 2006.
  • Description: C1
  • Description: 2003001589

Effects of windthrow on a Eucalyptus delegatensis (Myrtaceae) stand and early understorey succession at Snowy River National Park, Victoria

  • Authors: Florentine, Singarayer , Westbrooke, Martin
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Australian Forestry Vol. 67, no. 1 (2004), p. 54-58
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  • Description: During June 1998 a very strong windstorm at the Snowy River National Park ncar Mt Gelantipy caused severe damage to a stand of Eucalyptus delegatensis. Little is known about the impact of windthrow on E. delegatensis and subsequent seedling recruitment. This study was undertaken 4.5 y later 10 examine (i) windthrow damage to E. delegatensis and the understorey Acacia dealbata, (ii) the influence of tree size on the pattern of lree damage, (iii) the undergrowth in the windthrow area compared with that in control plots, and (iv) species composition of the soil-stored seed-bank in windthrow and control plots. We found that high winds toppled virtually all trees regardless of size and species, damaging 99% of the E. delegarensis. In windthrow plots there were 49 seedlings ha- I of E. delegarensis and 2210 ha-I of A. dealbata. No E. delegarensis or A. deafbara seedlings were recorded in the control plots. In the soil seed-bank study five species were recovered from soil samples collected from the control, and six from the windthrow-damaged sites. The canopy species E. delegatensis recruited only from the windthrow site. The exotic Rubus fruticosus was found to be colonising the windthrow site, but was not present in the control site. Results show that E. defegarensis recruitment is very poor in the damaged area, and species colonising within that area are light demanding or early succession species. It is proposed that seedling recruitment in the windthrow sites be accelerated by burning the site and broadcasting E. delega/ensis seed, or transplanting seedlings.
  • Description: C1
  • Description: 2003000710

Effects of windthrow on a Eucalyptus delegatensis (Myrtaceae) stand and early understorey succession at Snowy River National Park, Victoria

  • Authors: Florentine, Singarayer , Westbrooke, Martin
  • Date: 2003
  • Type: Text , Report
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  • Description: The June 1998 a severe windstorm at Snowy River National Park near Mt. Gelantipy caused severe damage to a stand of Eucalyptus delegatensis. Little is known about the impact of windthrow on E. delegatensis and subsequent seedling recruitment. This study was undertaken 4.5 years later to examine (i) the windthrow damage on E. delegatensis and the understorey Acacia dealbata (type of damage, diameter class distribution), (ii) the influence of tree size (diameter at breast height, 1.3m) on pattern of tree damage (snapped/uprooted/ snapped and resprouting) (iii) undergrowth in the windthrow area compared with control plots, (iv) species composition of soil stored seed bank in windthrow damaged plots and control plots. Eleven (25 x 25 m2) plots within damaged areas and five plots within undamaged (control) were selected for study. Tree diameter at 1.3 from the rooting point and type of damage (snapped, uprooted, snapped resprouted, snapped dead) were recorded. To examine seedling recruitment, each 25 x 25 m2 plot was further divided into 1 x 1 m2 sub-plots. Within each sub plot, all E. delegatensis seedlings and their diameters were recorded. Soil seed bank species composition was examined by taking 88 and 40 soil samples from windthrow and control sites respectively. Soil samples were placed in punnets and new recruits were counted and identified. This study showed that, high winds toppled virtually all trees regardless of size and species damaging 99% of E. delegatensis. Seedling recruitment was 49 ha-1 for the canopy species E. delegatensis and 2,210 ha-1 for the sub-canopy species A. dealbata. No E. delegatensis or A. dealbata seedlings were recorded in the control plots. In the soil seed bank study five species were recovered from soil samples collected from the control and six from the windthrow damaged sites. The canopy species E. delegatensis recruited only from the windthrow site. The exotic Rubus fruticosus was found to be colonizing the windthrow site, but was not present in the control site. Results show that E. delegatensis recruitment is very poor in the damaged area and species colonizing within the windthrow damaged area were light-demanding or early succession species. It is proposed that seedling recruitment in the winthrow sites be promoted by burning the site and broadcasting E. delegatensis seed.
  • Description: K1
  • Description: 2003000710

Controlling wind blown Lachnagrostis filiformis (fairy grass) seed heads in western Victoria

Does Geijera parviflora Lindl. (Rutaceae) facilitate understorey species in semi-arid Australia?

  • Authors: Warnock, Andrew , Westbrooke, Martin , Florentine, Singarayer , Hurst, Cameron
  • Date: 2007
  • Type: Text , Journal article
  • Relation: Rangeland Journal Vol. 29, no. 2 (2007), p. 207-216
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  • Description: Species composition under tree canopies often differs from that of surrounding micro-environments. In arid and semi-arid zones, trees can be beneficial to understorey vegetation. This study examined zones of vegetation composition and soil physiochemical parameters associated with Geijera parviflora Lindl. The importance of shade, rainfall redistribution, seed bank and soil moisture were examined. Species abundance, soil moisture, seed bank composition, rainfall redistribution and soil nutrient concentration were measured under five randomly selected mature G. parviflora trees in south-western New South Wales, Australia. To complement the findings from this study, artificial shade plots were constructed in a canopy-free area and species abundance measured seven months after shade construction. The study demonstrated that G. parviflora was associated with zonation of understorey vegetation. Two zones of understorey vegetation were found in relation to G. parviflora: (i) under the tree canopy with high species diversity, and (ii) beyond the canopy, this community being dominated by Dissocarpus paradoxus throughout the year with Crassula colorata appearing after rainfall. The zone beyond the canopy also had lower soil nutrient concentrations. Soil moisture, nutrient concentration and the seed bank density were significantly higher under the canopy. However, the canopy reduced precipitation reaching the soil surface. The effects of the canopy on understorey species composition and soil moisture were enhanced after winter rainfall. Artificial shade increased species abundance and richness under a 90%-shading treatment. The results indicated that G. parviflora generated spatial heterogeneity over the broader plant community increasing species richness, abundance and diversity under the canopy. This emphasises the importance of arid zone trees in conserving understorey plant diversity. Shading, soil nutrient concentration and increased seed bank density and soil moisture appeared to be key influences on the plant communities under the canopy. © Australian Rangeland Society 2007.
  • Description: C1
  • Description: 2003004817

Metal concentrations in rice and pulses of Samta Village, Bangladesh

The impact of deforestation and pasture abandonment on soil properties in the wet tropics of Australia

  • Authors: Rasiah, Velu , Florentine, Singarayer , Williams, B. L. , Westbrooke, Martin
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Geoderma Vol. 120, no. 1-2 (2004), p. 35-45
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  • Description: Limited information exists on the changes in soil properties, particularly from the wet tropics of Australia, under long-term abandoned pasture, which was previously grazed and was established on deforested tropical rainforest. This information may be help in successful forest reestablishment. The objectives of this study were to assess the cumulative impact deforestation, grazed and abandoned pasture on selected soil physico-chemical properties from (i) an abandoned pastureland and (ii) a recently planted rainforest (PRF), planted in the abandoned pastureland. The experimental site is a field in the Northeast Queensland (NEQ) wet tropical region of Australia. This site was deforested approximately 70 years ago and brought under unfertilized grazed pasture for 30 years. Subsequently the grazed pastureland was abandoned and remains un-grazed for 40 years. A section of the abandoned pastureland was planted, 10 years ago, with native forest species, involving different combinations in five treatments in a completely randomised block design. A nearby undisturbed rainforest is used as the background against which assessment was carried out. Soil samples from 0- to 15-cm depth were collected in July 2000 and analyzed for nitrate-N, ammonium-N, total N, total soil organic C (SOC) and labile-C, pH (in water and CaCl2), electrical conductivity (EC), exchangeable Ca, Mg, Na, K, and Al, and bulk density. Compared to the rainforest, the N and C concentrations of different forms under abandoned pasture and PRF were significantly less, exclusive of the total N under abandoned pasture. More specifically, the SOC under the abandoned pasture was 37,600 mg/kg compared with 74,800 mg/kg under rainforest and 27,000 mg/kg in the PRF. The exchangeable Al under rainforest was 8.5 c molc/kg compared with 42. 4 to 80.2 c molc/kg under abandoned pasture and PRF. In general exchangeable cations (sum of Ca, Mg, K, and Na) under the rainforest were higher than the abandoned pasture. Soil under the abandoned pasture and PRF are more acidic by 0.5 to 1 units than the rainforest. Higher bulk densities under abandoned pasture and PRF led to 0.03% to 0.07% reductions in total porosities. Though we did not anticipate the soil under the abandoned pasture to recover 100% in 30-40 years, the results indicate that 40 years under abandoned pasture or 30 years of abandoned pasture plus 10 years under PRF was not sufficient to bring about substantial improvement in soil properties comparable to the rainforest. This implies the resiliency of tropical soils, in general, to recover from deforestation and cultivation induced degradation is poor. © 2003 Elsevier B.V. All rights reserved.
  • Description: C1
  • Description: 2003000713

Allelopathic potential of the newly emerging weed solanum mauritianum Scop. (solanaceae) in the wet tropics of north-east Queensland

Post-wildfire seedling colonisation patterns in a Eucalyptus delegatemsis (Myrtaceae) windthrow site at Snowy Rover National Park, Victoria

  • Authors: Florentine, Singarayer , Westbrooke, Martin , Milberg, Per , Gibson, Matthew
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Australian Forestry Vol. 71, no. 1 (2008), p. 48-53
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  • Description: During June 1998, a severe windstorm caused significant damage to a sub-alpine stand of Eucalyptus delegatensis (Myrtaceae) at the Snowy River National Park. In 2002, about 4.5 y after the windstorm, a study documented the effects on E. delegatensis and early understorey succession. In February 2003, wildfire burnt across the windthrow site and we examined the seedling recruitment patterns at windthrow–burn and burn-only sites. Our aim was to document the regeneration of the canopy-dominant E. delegatensis and to confirm that Acacia dealbata is a pioneer species that potentially interferes with or prevents regeneration of E. delegatensis. Permanent transects were established within the windthrow–burn and burn-only sites. The data suggest that the heavily disturbed (mounded) soil at the windthrow site had a strong positive influence on regeneration of both species. By providing favourable growing conditions, the disturbed soil appears to have assisted seedling survival and subsequent growth of the E. delegatensis, despite competition from dense, concurrently established A. dealbata.
  • Description: C1

Arsenic contamination in Bangladesh groundwater : A major environmental and social disaster

  • Authors: Alam, M. G. M. , Allinson, Graeme , Stagnitti, Frank , Tanaka, A. , Westbrooke, Martin
  • Date: 2002
  • Type: Text , Journal article
  • Relation: International Journal of Environmental Health Research Vol. 12, no. 3 (2002), p. 236-253
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  • Description: In attempting to eliminate disease caused by drinking polluted surface water, millions of shallow surface wells were drilled into the Ganges delta alluvium in Bangladesh. The latest statistics indicate that 80% of Bangladesh and an estimated 40 million people are at risk of arsenic poisoning-related diseases because the ground water in these wells is contaminated with arsenic. The clinical manifestations of arsenic poisoning are myriad, and the correct diagnosis depends largely on awareness of the problem. Patients with melanosis, leuco-melanosis, keratosis, hyperkeratosis, dorsum, non-petting edema, gangrene and skin cancer have been identified. The present article reviews the current arsenic contamination of ground water, hydrological systems, groundwater potential and utilization and environmental pollution in Bangladesh. This paper concludes by clarifying the main actions required to ensure the sustainable development of water resources in Bangladesh.
  • Description: 2003000124

The mammals of Parker River Inlet National Park, Otway National Park

  • Authors: Westbrooke, Martin , Prevett, Patrick
  • Date: 2002
  • Type: Text , Journal article
  • Relation: The Victorian Naturalist Vol. 119, no. 2 (2002), p. 60-68
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  • Description: Studies of small mammals at Parker River Inlet from 1985-95 have demonstrated the presence of ten species of small mammals. Trapping, spotlighting and incidental sightings have shown that a further 18 species of mammals occur within an area of 200 ha. Pseudomys fumeus and Antechinus minimus, recorded in this survey, are rare and restricted in Victoria. The species richness of the area is related to the heterogeneity of the vegetation, with twelve vegetation types being identified in the study area. The occurrence of the more abundant small mammals, Rattus fuscipes, Rattus lutreolus, Mus musculus and Antechinus swainsonii, is correlated with vegetation structure and floristics. Causes of fluctuations of the populations of the exotic species M. musculus and Rattus rattus are considered. Management recommendations, which reflect the high significance of faunal habitat in the area, are made with the aim of minimising human impact.
  • Description: C1
  • Description: 2003000129

Observations on survival and early growth of natural regeneration in floodplain coolibah Eucalyptus victrix (Myrtaceae) in the Pilbara, Western Australia

  • Authors: Fox, John , Florentine, Singarayer , Westbrooke, Martin , Hurst, Cameron
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Rangeland Journal Vol. 26, no. 2 (2004), p. 150-160
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  • Description: Observations are presented on the natural regeneration of Eucalyptus victrix L. Johnson and K. Hill (coolibah), the dominant tree species of grassy woodlands on the floodplain of the Fortescue River, north of Newman in the Pilbara district of Western Australia. The main objectives of this study were to examine: (i) survival of newly recruited E. victrix seedlings on flooded and burnt sites, and (ii) growth and survival of established plants in a gilgaied landscape. Populations of newly-recruited seedlings following flooding or fire were monitored opportunistically at 'Marillana' and 'Ethel Creek' stations, for up to two years from tagging. A population of saplings at 'Roy Hill' station was observed over eight years. Seedling densities of E. victrix in flooded sites were 0.32 and 1.03 plants/m2 in 1995 and 1997 respectively. Locally high densities reached from 1.2 to 17.7 plants/m2 on areas of 28 and 6 m2 respectively. At the burnt site at 'Ethel Creek', 1.30 plants/m2 were observed where 58 seedlings were recorded on an area of 445 m2 a year after a natural fire. Many of these persisted well into their second year, whereas seedlings recruited in the flooded sites generally lasted less than a year (250-376 days). In contrast, persistence of a cohort of 100 established saplings <2 m tall in a gilgaied landscape at 'Roy Hill' was high. During 8 years of observations, only one sapling was lost. Those found at the edges of gilgais had attained greater heights (3.91 ± 1.14 m) than saplings located inside (3.16 ± 0.95 m) or on top (3.12 ± 0.93 m) of the gilgais. This study demonstrates that the seedling stage in E. victrix is critical, in that once newly recruited individuals reach the sapling stage (0.6-1 m), mortality rates are much reduced. Unfortunately, it was not possible during the course of this study to locate a cohort of young seedlings that did survive and so any consideration of the conditions necessary for their survival is speculative.
  • Description: C1
  • Description: 2003000725

Macroinvertebrate communities in willow (Salix spp.) and reed beds (Phragmites australis) in central Victorian streams in Australia

  • Authors: Jayawardana, Chandamali , Westbrooke, Martin , Wilson, Michael , Hurst, Cameron
  • Date: 2006
  • Type: Text , Journal article
  • Relation: Marine and Freshwater Research Vol. 57, no. 4 (2006), p. 429-439
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  • Description: Exotic willows (Salix spp.) are widespread riparian tree species of rivers in temperate Australia and New Zealand. Despite being considered as a weed of national significance, little is known about the habitat value of willows and the impact on aquatic biota of vegetation change following willow management programmes. Macroinvertebrate fauna in root habitats of willows and Phragmites australis habitats were examined in three central Victorian rivers to understand the effect of such littoral habitat changes on macroinvertebrates. Data were analysed using Partially Nested Factorial ANOVA with season, river and habitat as main effects. Habitat structure had a significant effect (P < 0.05) on macroinvertebrate community assemblage. However, effect of habitat was not consistent among seasons. The greatest community differences among habitats were observed during winter and least separation during autumn. Taxa responsible for community differences among habitats were also identified. Species richness and abundance did not show consistent variation among habitats over different rivers or seasons. This study provided some indication of the macroinvertebrate community changes that would take place in situations where riparian vegetation changes takes place from willows to P. australis. © CSIRO 2006.
  • Description: C1
  • Description: 2003001620