Birds in Western Australian wheatbelt reserves—implications for conservation

Bird species richness in 22 reserves in the Western Australian wheatbelt was shown to be related not to isolation from adjacent uncleared land, either spatially or with time since clearing of land in their vicinity, but to area of reserve and certain reserve habitat variables. The nature of these relationships was examined with multiple regression analysis. Reserve area was the most important variable, except in some passerine groups, where numbers of plant species, vegetation associations, and plant life form and density classes in each vegetation stratum were, separately, more important than area. Eighty-two percent of the variation in the number of bird species was explained by area of reserve and number of plant species, indicating the importance of floristics to the total bird assemblage within reserves. The number of formations present (the broadest vegetation structural grouping used) did not explain any of the variation in species numbers in any of the bird groupings.There were more resident passerine species present in wheatbelt reserves than there were breeding passerine species on similar-sized southwestern Australian late-Pleistocene/Holocene islands, although the species versus area relationship of the resident habitat-specific passerines (P₅ group) was very similar to that of the island land-bird faunas. The P₅ species group contained many species which probably responded to wheatbelt reserves as islands; some of these species may fail to persist in the wheatbelt in the long term. Twenty-three species usually resident in reserves and 15 ‘non-residents’ were identified as being ‘vulnerable’ or of uncertain conservation status in the wheatbelt.Some vegetation formations within reserves were more important to birds than others; woodlands were most important both to resident and transient species. Most species do not appear to distinguish between shrublands and heaths as major habitats; Species richness versus formation area relationship suggest that insular patchiness for birds in the wheatbelt was manifest at the level of vegetation formations. Reserves as small as 80 ha were important sanctuaries for birds in the wheatbelt, although 1500 ha was considered a minimum area of reserve to conserve a local avifauna. Reserves of the order of 30,000–94,000 ha were required to contain most of the avifauna of the wheatbelt.     

Cadmium Accumulation in Agricultural Soils in Western Australia

Water, Air, & Soil Pollution - Phosphatic fertilizers contain appreciable concentrations of cadmium (Cd) which may elevate the Cd concentrations of soils and crops, yet the impact of Cd on...     

Conservation genetics and implications for restoration of Hemigenia exilis (Lamiaceae), a serpentine endemic from Western Australia

Hemigenia exilis (Lamiaceae) is a rare plant endemic to serpentine soils of the Goldfields of Western Australia. The species was presumed extinct until 1995, when it was re-discovered on a nickel ore deposit. To delineate the origin and extent of seed collection for rehabilitation after mining, and to identify the impact of removing one population due to mining, we assessed level and partitioning of genetic variation and differentiation. Twelve populations were sampled for DNA fingerprinting using the random amplified polymorphic DNA (RAPD) technique. Ten primers produced 89 bands, 97% being polymorphic. Genetic diversity within populations ranged from 0.197 to 0.409, averaging 0.38 at the species level, which is high compared with most other endemic species. Heterozygosity within populations ranged from 0.355 to 0.431, averaging 0.27 over the species. AMOVA partitioned over 80% of the total variation within populations. Multidimensional scaling revealed weak but significant differentiation into a northern and southern provenance. Despite selective sampling, the genetic data provided useful information for the management of Hemigenia exilis. For restoration, seed should be collected from a range of habitats of several populations, while keeping the two provenances separate. This strategy is likely to maintain high genetic diversity and locally adapted populations.     

Iron oxides in lateritic soils from Western Australia

Lateritic soils developed from dolerite contained larger amounts of goethite and haematite than those developed from granite. The goethite/(goethite + haematite) ratio in granitic soils ranged from 0.55 to 1 and from 0.29 to 0.83 in doleritic soils. Maghemite ranged in abundance from 0 to 10% and it only occurred in duricrust. Mole % Al substitution ranged from 16 to 33% in goethite and from 2.5 to 10% in haematite and was similar for both granitic and doleritic soils. Al substitution in maghemite was <5%. A significant, positive correlation (P<0.01) occurred between Al substitution in goethite and the amount of gibbsite in the soil. The dehydroxylation temperature of goethite ranged from 292 to 334°C and was positively correlated with the mole % Al substitution. Goethite crystals varied in size from 16 to 26 nm and haematite crystals from 18 to 59 nm. Goethite and haematite crystals occurred as aggregates of subrounded platy crystals.
Iron oxides obtained by NaOH treatment contained much of the minor element contents of the soils; mean concentrations (μg g⁻¹) were: Zn 19.9, Cu 31, Mn 68, Ni 140, Co 32, Cr 394 and V 696. These minor elements were most abundant in iron oxides derived from dolerite, but were not preferentially associated with goethite or haematite.     

The impact of marine reserves on nekton diversity and community composition in subtropical eastern Australia

The effectiveness of marine reserve protection on the biodiversity of aquatic assemblages (i.e. nekton) in subtropical eastern Australia was examined within two small (<6 km²) marine reserves and four non-reserve areas. The two marine reserves, and their corresponding non-reserves, were located in different geographical locations within Moreton Bay (north and south) and sites were surveyed with multiple hauls of a seine net. Species richness, evenness, density and mean size of the inshore communities were compared between the reserves and non-reserves. No statistical significant difference was detected in species richness between the areas however species evenness was significantly lower in the only non-reserve site impacted by commercial net fishing. Mean size of nekton was found to be significantly greater in the marine reserves compared to non-reserves but no statistical significant difference was found in the density of nekton between the study sites. Multivariate analysis revealed differences in community composition, particularly between the geographical locations where areas were impacted by different types of fishing pressure (recreational v commercial). These results highlight the impact commercial fishing can have on entire nekton assemblages, not just on targeted species. Our study demonstrates that the small marine reserves in Moreton Bay are protecting marine biodiversity and are thus at least partially achieving their management objective (to enhance the zone’s marine biodiversity).     

Conservation of the short-tailed shearwater Puffinus tenuirostris in Tasmania,Australia

The number of short-tailed shearwater burrows in Tasmania is estimated at 11·4 million of which 80% are annually occupied by breeding birds. Chicks are exploited for food in March and April, and prior to the season usually 50% of burrows contain chicks. The annual commercial harvest is about 400 000 chicks taken from seven colonies containing 5·63 million burrows. This take is well below the maximum sustained yield of 37% of chicks available and represents 14% of the estimated 2·82 million chicks present. The non-commercial harvest is estimated to be 300 000 chicks taken from 104 colonies containing an estimated 1·51 million burrows. Monitoring has shown that on many popular colonies the takes are well in excess of the maximum sustained yield, and management measures to reduce it have been introduced. The short-tailed shearwater is in no danger of decline despite harvesting.     

Bird utilisation of rehabilitated bauxite minesites in Western Australia

Alcoa of Australia Limited rehabilitate bauxite mined areas in the southwest of Western Australia. One of the aims of the revegetation programme is to promote the return of fauna species which inhabited areas prior to mining.This paper discusses the extent to which bird species utilise revegetated bauxite minesites. It was shown that revegetated areas as young as 4–5 years can support similar bird species numbers, densities and diversities as unmined forest. However, the avifaunal populations occupying any rehabilitated area depend largely on the rehabilitation technique used. Factors which may be used to increase further avifaunal utilisation of minesites are discussed.The effects of jarrah dieback and fire on forest birds are compared with results for bauxite mined areas. From this, it is possible to assess the combined impact of dieback, fire and mining on the longer term conservation of jarrah forest bird species.     

Management of soil water for wheat production in Western Australia

Abstract. Spring wheats are sown in autumn and mature under conditions of spring water deficits in Western Australia. While grain yields are very small (averaging 1.05t ha^-1), water-use efficiencies ( WUE ) of crops grown with good management compare favourably with the rest of Australia at 10 kg grain ha^-1 mm^-1. Major water loss, calculated at an average 40% of growing-season rainfall, occurs through evaporation from the soil surface, and in some years significant losses also occur through deep drainage on sandy soils. Evaporation losses can be reduced by stubble retention and adding gypsum to improve filtration on structurally unstable, fine-textured soils. More general increases in crop water use occur through all agronomic factors which result in rapid and uniform plant cover as early as possible after break of season. This includes adequate fertilization, weed control and narrow row-width. Wheat crops sown after pasture and grain legumes consistently outyield all-cereal rotations.     

survival of field-grown rhizobia over the dry summer period in Western Australia

The survival over summer of field-grown root nodule bacteria was studied in the field and the laboratory during the course of an investigation into a nodulation problem of annual clovers. Dry field soils containing Rhizobium trifolii and R. lupini were subjected to a range of temperatures in the laboratory, the bacteria surviving 6 h exposure to temperatures as high as 80°C. Soil temperatures during summer were recorded at different depths. Populations of rhizobia were estimated at these depths from the end of the growing season (October) to early autumn (April) in plots which had carried dense swards of subterranean clover and Serradella. High populations of R. lupini were maintained in the Serradella plots throughout the summer. Populations of R. trifolii in the subterranean clover plots were initially much lower, and declined with both time and depth.The problem known as ‘second-year clover mortality’ is primarily due to low numbers of clover rhizobia in the soil at the end of the growing season. This situation is aggravated over the long hot dry summer, when there is a further decline in numbers.     

Conservation strategies in response to rapid climate change: Australia as a case study

As in all parts of the globe, rapid climate change in Australia will have significant negative impacts on biodiversity. It also will interact with pre-existing stressors such as native vegetation clearing, altered natural disturbance regimes and invasive species - all of which already have major negative effects on biota in Australia. Strategies to reduce climate change impacts on Australian biodiversity include a mixture of mitigation and adaptation actions (sensuMillar et al., 2007) such as: (1) significantly reducing greenhouse gas emissions, (2) ensuring bio-diverse carbon capture, (3) better tackling pre-existing stressors on biodiversity, (4) better preparing for the effects of major natural disturbances, (5) significantly improving off-reserve conservation efforts including fostering appropriate connectivity, and (6) enhancing the existing reserve system by making it more comprehensive, adequate and representative. The first strategy above demands a global response otherwise major mitigation attempts in Australia that are not paralleled elsewhere around the world will have little effect on climate change and, in turn, contribute little to enhanced biodiversity conservation. Strategies 2-6 demand multi-scaled responses, particularly at a regional level, given the major regional differences in direct climate change impacts and their interactions with pre-existing regional stressors. Well developed multi-scaled conservation plans to implement these strategies currently do not exist, nor do appropriate institutional arrangements and capacities. Institutional reforms are urgently needed in Australia to develop the land management, monitoring and regional response capabilities required to conserve biodiversity on a continent already significantly modified.     

Aquatic Ecosystem Degradation of High Conservation Value Upland Swamps,Blue Mountains Australia

Temperate highland peat swamps on sandstone (THPSS) are unique state and federally protected ecological communities. THPSS is a higher level classification which is comprised of multiple swamp communities which include Blue Mountains Swamps and Newnes Plateau Shrub Swamps. The Blue Mountains has a string of urban settlements surrounded by large expanses of undisturbed natural vegetation which have varied degrees of protection ranging from state forests to World Heritage national parks. This study investigated aquatic invertebrates from seven THPSS within the Greater Blue Mountains area. Four swamps drain catchments with varying degrees of urban development and associated impervious surfaces, and three swamps have non-urban, naturally vegetated catchments. Water chemistry of non-urban swamps was acidic (mean pH 4.70) and dilute (mean EC 26.7 uS/cm) and dominated by sodium and chloride ions with most other major ions at low concentrations often below detection limits (Belmer et al. 2015). In contrast, urban swamps had higher pH (mean 6.60) and salinity (mean 153.9 uS/cm) and were dominated by calcium and bicarbonate ions (Belmer et al. 2015). Aquatic macroinvertebrate abundance, family richness and % EPT taxa were all found to be lower within urban swamps when compared to non-urban swamps. These results support the hypothesis of Belmer et al. (2015) that urban runoff within THPSS catchments is affecting the condition of their aquatic ecosystems.     

Relationships between micromorphological soil features and known stratigraphic layers in Western Australia

Micromorphological data were collected from a known layered situation in south western Australia in an effort to determine whether pedological features and soil fabrics could provide a basis for identifying the presence of rock- and soil-stratigraphic units in whole soil profiles. The use of depth functions as a basic micromorphological research technique is evaluated with regard to the recognition of sedimentary characteristics in soils and the identification of strarigraphic discontinuities. Results of this study suggest that multiple peaks in frequency-distribution patterns of pedological features are indicative of polygenesis because each peak correlates with a surface (contemporary) or buried (relic) soil profile. The analysis of soil fabric assemblages appears to provide an additional basis for differentiating soil materials. The recognition of inherited soil features facilitates tracing the provenance of soil parent materials.     

Constraints to farmers managing dryland salinity in the central wheatbelt of Western Australia

There is an increasingly well‐founded understanding of the chief drivers and constraints to widespread adoption by Australian landholders to practices to manage dryland salinity. However, each specific situation depends on a range of biophysical, social and economic factors. Such is the case in this study that examines farmers' salinity management in the Wallatin‐O'Brien catchments in the low‐medium rainfall zone of the Western Australian wheatbelt. The study involved interviews with landholders and economic modelling of representative farms and salinity management options to gain an understanding of the farmers' adoption behaviour regarding salinity management. Most landholders interviewed saw dryland salinity as a second order farm management issue, due first to the relatively slow rate of expansion of saline land within the catchments and second, because the changes in land use required to prevent further loss of land to salinity were viewed as being uneconomic. The exception to this was the minority (<15 per cent) of farmers in the catchment that have most of the saline land and have experienced most of the recent increase, and for these farmers (primarily located in the valley floor) salinity is a pressing issue. The scale and pattern of isolated outbreaks on adjacent slopes means that salinity is merely a nuisance problem for farmers who only have this type of salinity. For all farmers, a disincentive to invest in salinity management was the landholders' lack of knowledge about the proper placement, needed scale of adoption and economic viability of salinity management options. Saltland pastures, surface water management and lucerne were viewed positively, with several desirable characteristics such as ease of trialling and complementarity to existing farm practices. By contrast, engineering options such as deep drainage, where considerable investment is involved and disposal of groundwater is problematic, were rated less favourably. Bioeconomic modelling of these salinity management options generated results that largely confirmed the merits of what landholders in the catchments currently do. The findings showed that there was little economic merit in wide‐scale adoption of these salinity management options in these catchments. However, the findings did highlight the need to match salinity management options to a farm's particular circumstance, if best use of the options is to be made by the different farms in the catchments. Copyright © 2009 John Wiley & Sons, Ltd.     

Relationship between rainfall-adjusted nitrogen nutrition index and yield of wheat in Western Australia

Abstract

Insufficient nitrogen applications may contribute to yield gaps in low rainfall environments of Western Australia (WA). This study tested a nitrogen nutrition index (NNI) for wheat tailored for low rainfall regions, which is based on rainfall-scaled dilution curves. We analyzed yield, shoot biomass, and nitrogen concentration from 32 field trials in WA. An empirical rainfall threshold of 400?mm (summer?+?growing season rainfall) returned two parallel dilution curves accounting for the reduction of critical N in drier and lower yielding conditions. Scatterplots of relative yield and rainfall-adjusted NNI returned a robust boundary function that may lead to greater adoption by growers. The NNI defined in this research study can be applied and further tested by growers in WA, but may also apply to other low rainfall environments, to close nitrogen related yield gaps.     

Geostatistical analysis of the spatial variation of the ash reserves in the litter of bog birch forests in Western Siberia

A typological series of native Betula pubescens Ehrh. dendrocenoses along the channel of a river crossing a bog was studied. The variability of the mineral element reserves is described by geostatistical methods as the sum of a trend, autocorrelation, and random components. The contribution of deterministic and random components has been assessed in the years with average precipitation and in the year of 2007 with high and long-term flooding. The empirical variograms and the parameters of the model variograms are presented. The class of the spatial correlation of the ash reserves is described. A primary cause of the ash content’s variability is the specific water regime, which is determined by the following: (i) the abundance and duration of the spring floods responsible for the silt mass brought by the river and (ii) the draining effect of the intrabog river, the distance from which provided the formation in the forest of the ground cover with the specific species composition and ash content. The falloff of the arboreal layer in the bog birch forests formed the fundamental mineral background of the litter.     

Awareness and consumption of folate-fortified foods by women of childbearing age in Western Australia

OBJECTIVES: The introduction of voluntary fortification of some foods with folic acid in Australia has been implemented since evidence of the prevention of neural tube defects with periconceptional folic acid was published. Our objectives were to determine how many women were aware of folate and when they became aware, what was the awareness of labels on foods that mentioned folate, and how much folate-fortified food women ate. METHODS: To address these objectives we collected data by self-administered questionnaire from a random sample of 578 recently pregnant women in Western Australia between September 1997 and March 2000. RESULTS: Overall, 89% of women had heard, seen or read anything about the link between folate and birth defects such as spina bifida, 62% first became aware of the folate message before their recent pregnancy and 42% of women noticed any labels on foods that mention folate before or during their recent pregnancy. Overall, 53% of women were aware of foods that have folate added to them and 33% usually or always read the labels on food packaging. The folate-fortified foods most often consumed by women were cereals (69%), breads (34%) and milk (15%). Of the women who consumed folate-fortified foods (78%), the earlier they became aware of the folate message and noticed labels on food, the more fortified foods they consumed. CONCLUSIONS: These results indicate that staple foods fortified with folate are consumed by almost 80% of women in the population. Therefore, mandatory fortification of staple foods may reach most women, providing improved opportunity for the prevention of neural tube defects in Australia.     

水土保持是西部大开发的基础

水土保持是西部开发的基础和关键。水土保持生态环境建设 ,要搞好规划、重视工程质量、加强监督管理、提高科技含量 ,要加大坡改梯力度、加强城市水保、加大执法力度、坚持综合治理     

Distribution of Heavy Metals in Near-Shore Sediments of the Swan River Estuary,Western Australia

Estuarine systems adjacent to urban areas are at risk of contamination by contaminants from anthropogenic sources, such as heavy metals. We anticipated that the sediments of the Swan River estuary, which runs through metropolitan Perth in Western Australia, would show metal contamination related to industrialization and inputs of stormwater. Total Cu, Pb and Cd concentrations, and Cu, Pb, Cr and Zn inoperationally-defined fractions, were determined inseparate sampling exercises in near-shore sediments ofthe upper Swan River estuary.Total metal concentrations in sediments were not high (maximum values of 297 mg kg^-1 for Cu, 184 mg kg^-1 for Pb and 0.9 mg kg^-1 for Cd) when compared with Australian environmental assessmentguidelines for soils. On the basis of linear regressions between sediment metal concentrations andphysicochemical properties of the sediments (pH, organic carbon, particle size distribution), no single parameter could explain the variation in metal concentrations for all metals. Sediment organic carbon content was positively correlated with Cu concentration; Cu concentrations also increased significantly with increasing clay content anddecreasing sand content. Pb concentrations showed a significant increase with increasing sediment pH, and were approximately three-fold higher in sediments adjacent to stormwater drain outfalls than in sediments remote from drains; no such effect was observed for Cu or Cd. No effect of distance downstream was observed. Sequential extraction of sediments showed that most of the metals were in relatively immobile forms, for example bound to Feoxides, or only extractable by aqua regia. The enhanced concentrations of Pb near stormwater outfalls suggest that vehicle-derived Pb may be an important contributor of Pb to the estuary.     

Cultivars of canola respond similarly to applied nitrogen in n-deficient soils of south Western Australia

Six cultivars of canola (Brassica napus L.) were grown with six levels of applied nitrogen (N) fertilizer (urea 46% N) at six locations in south Western Australia (SWA) during 2010 and 2011. The aim of the experiment was to determine if the seed yield (SY) increase (response) of the canola and associated herbicide technologies were different to applied N. Open pollinated (OP) and hybrid cultivars of associated herbicide technologies (Triazine Tolerant, TT; Roundup Ready, RR; Clearfield, CL) were used. Varieties had large SY differences with no N applied. Generally, RR hybrid of 2011 tended to have the highest SY, except for Katanning 2011 where several varieties obtained the same SY. The average amount of N required for 90% of the maximum SY was 113 kg N ha^?1 and economic breakeven N rates were less than or equal to 100 kg applied N ha^?1. The average rate of return on investment in fertilizer N was $1.60.

In four out of six experiments RR hybrids had the highest oil concentration with no applied N. N decreased the oil concentration in all canola types, except at Gibson 2010. At Gibson in 2010, N application increased the oil concentration to about 100 kg N ha^?1 with further additions of N decreasing the oil concentration. There was a linear relationship where N application decreased the oil concentration and increased protein concentration of the seed. In this study, the summation of oil percentage and protein concentration in the seed was on average 65%, with RR hybrids producing 67%.

In most aspects, RR hybrids outperformed RR, OP and other canola types; however, hybrid TT and hybrid CL canola did not consistently outperform their OP counterpart. We suggest that current N fertilizer recommendation models are useful for all canola types currently grown in SWA; however, adjustments should be made to take into account the higher SY and oil concentration potential of RR hybrids compared to TT canola at every rate of applied N.