SE Australia Research Articles

DRIP IRRIGATION DISTRIBUTION UNIFORMITY IN VINEYARDS OF AUSTRALIA: TOOLS FOR MAPPING AND ESTIMATION OF IMPACTS

Increasing pressure is being placed on water resources due to the extensive drought and low water allocations in Australia. This has caused a shift to pressurized irrigation systems for many crops. Essential to getting the high returns required is that the irrigation system performs at high levels of distribution uniformity to maximise uniformity of crop and provide more efficient use of water and fertiliser. In commercial situations, field evaluations of drip irrigation systems are often overlooked with many growers taking for granted their system is behaving according to the design specification. Drip irrigation systems theoretically have high distribution uniformities and application efficiencies, however in commercial field systems these theoretical efficiencies can be difficult to achieve. This paper outlines recent research monitoring actual distribution uniformities in vineyards of SE Australia and the impact on total water applied over a season and also fertiliser application. The paper also outlines how satellite derived NDVI remote sensing measurements can be used for targeting sampling strategies to perform performance assessments on drip systems. The paper also outlines the development of a web based interface (http://www.irrigateway.net/tools/du/) developed to simplify the analysis of field collected data and relate this performance to indicators which can clearly be understood by irrigators - such as effects of poor distribution uniformities on seasonally applied water and nitrogen fertigation.This paper addresses these issues and describes implications of poor distribution uniformity on crop performance, especially when watering below maximum crop water requirement and as such falling into a higher risk region on the irrigation:yield production function. This is done using an adapted crop growth model that accepts spatial input data for irrigation and fertiliser.

Towards Evidence-based Water Management in the Murray Darling Basin, Australia

The paper introduces a Special Feature of Wetlands concerned with the ecology and management of the Murray Darling Basin, Australia. The Murray and Darling River systems in SE Australia combine to form the largest draining basin on the continent and the most economically important. The river system supports 16 wetlands listed as internationally important under the Ramsar convention, and sustains nationally significant populations of waterbirds, and endemic flora and fauna. Many of these values have been threatened by the development of water resources, particularly in the southern tributaries, and the diversion of water for irrigated agriculture. The restoration of ecological health within the Murray Darling is contingent on the optimal use of water reserved for environmental use. This objective can only be achieved through the development and application of quantitative, testable models linking environmental water regimes to ecological outcomes. This Special Feature of Wetlands explores the use of evidence in support of environmental water management, with papers considering the standards of evidence, the testing of assumptions relating to indicator species, the formulation of empirically-based flow-response models and the incorporation of these relationships in decision support tools. The further testing and development of quantitative predictive models is advocated as a key objective of environmental flow monitoring.

Interactions between dense Callitris regeneration and Eucalyptus and Callitris canopy trees in semiarid woodlands

Since European settlement, woodlands have undergone significant structural and compositional changes in semiarid SE Australia. With logging, introduced grazing and declines in fire frequency, fire-sensitive Callitris glaucophylla has regenerated densely in woodlands dominated by C. glaucophylla and fire-tolerant Eucalyptus species. Since little is known about long-term competitive interactions between sapling regeneration and canopy trees, we examined: (1) how established Eucalyptus and Callitris canopy trees influence survival, growth and reproduction of Callitris saplings; (2) whether dense Callitris regeneration affects canopy tree health during drought; and (3) whether these patterns differ along a rainfall gradient (363–621 mm year–1). Callitris saplings beneath tree canopies were less dense, smaller, and less likely to fruit than isolated saplings in gaps along the rainfall gradient. Callitris trees surrounded by Callitris regeneration had greater mortality than those without surrounding regeneration; Eucalyptus trees were more likely to be drought stressed at the lower end of the rainfall gradient, where canopy trees were at higher densities. The results suggest that canopy trees reduce the density rather than exclude Callitris regeneration, and that the regeneration contributes to mortality of Callitris canopy trees during drought. The trend towards increasing Callitris dominance is expected to continue over time, owing to the paucity of Eucalyptus recruitment.

SEBAL-METRIC ESTIMATES OF CROP WATER REQUIREMENT IN HORTICULTURAL CROPS GROWN IN SE AUSTRALIA

ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on CLIMWATER 2010: Horticultural Use of Water in a Changing Climate SEBAL-METRIC ESTIMATES OF CROP WATER REQUIREMENT IN HORTICULTURAL CROPS GROWN IN SE AUSTRALIA

Onshore Bar Migration in a Fetch/Limited Strong Wind Bay

WONG, H and STEPHENSON, W., 2011. Onshore Bar Migration in a Fetch/Limited Strong Wing Bay. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 458-469. Grosseto, Tuscany, Italy, ISSN 0749-0208.This paper investigates bar migration in a fetch limited strong wind bay (Seaford Beach SE Australia). Onshore bar migration on open ocean beaches is dependant on long period swell wave and occurs during low energy conditions. However, in a fetch limited environment such waves are absent and most studies suggest that during low energy conditions the beach remains in an arrested state (Jackson et al. 2002). This paper spans a three month study period (15th March – 8th June 2008). Measurement of near shore morphology and wind data were collected. The two bars at Seaford behaved very differently; both onshore and offshore migration was detected during the three recorded storm events. The paper found that, firstly, wave breaking was incomplete in the middle bar during event 1 — the inner bar migrated offshore. Secondly wave breaking in the middle bar was almost complete during event 2 and the inner bar migrated onshore. Thirdly when wave breaking was complete in the middle bar during event 3 — the inner bar remained arrested on some profiles but bar height increased on others. The wave steepness threshold for onshore migration of the inner bar was parameterized s 0.041 – 0.042. Beach sediment modeling in fetch limited strong wind bays remains understudied. Our results should help to improve the predictive capability of beach sediment budgets in fetch limited strong wind bays.

Short-term effects of experimental fire for a soil under eucalyptus forest (SE Australia)

The effects of different fire intensities on physiochemical soil properties have been studied in this research. The experiment was conducted in a eucalyptus forested area near the Namadgi National Park (ACT, Australia), and four fire intensities were achieved by adding different amounts of fuel load: 0 kg m − 2 (control), 2 kg m − 2 (low fire intensity), 4 kg m − 2 (moderate fire intensity) and 8 kg m − 2 (high fire intensity). Soil surface peak temperatures reached at each plot were 14, 142, 317 and 525 °C, respectively. Immediate changes in soil properties under different fuel loads were studied and monitored monthly during a 7-month period. Average pH increased significantly with fuel load immediately after fire and decreased progressively to initial values. Changes in soil pH from burnt plots seem to be caused mainly by an ephemeral ash layer, and the recovery time has been relatively short. The complete oxidation of soil organic matter and the release of substantial amounts of cations after high fire intensity also contributed to increased pH. Only small variations in soil texture have been observed in this study even after high intensity fire, although the clay content decreased slightly during the experiment. This can be due to relatively low pre-burn clay content, but also to spatial variability of texture. In this case, post-fire erosion processes might have contributed to decreased clay content and are probably more important than other processes associated to temperature. Aggregate stability indices showed good correlation coefficients with the organic matter content. The role of organic matter as cementing agent of soil aggregates is extremely important after fire, since aggregate stability indices showed good correlation coefficients with the organic matter content. Low intensity fire enhanced soil water repellency. In this case, fire-enhanced soil water repellency persisted or increased progressively, but decreased below initial levels at the end of the experiment, but soil water repellency was completely destroyed after moderate or high fuel load treatments. The persistence of wettable conditions after destruction of soil water repellency can be considered as an index of fire severity, since it is a direct consequence of strong reduction of organic matter content.

Transient electromagnetic surveys for the measurement of near-surface electrical anisotropy

Abstract Structural and petrological anisotropy can cause significant complications during any interpretation of electrical and electromagnetic surveys. New methods are presented here for the determination of the direction and magnitude of lateral anisotropy via measurement of the rate of diffusion for eddy current systems generated in a transient electromagnetic (TEM) sounding. We use the smoke-ring analogy for the current induced in the ground and measure its radial propagation by tracking the change of sign measured in the receiver coil at a range of distances from the transmitter-loop centre. A slower signal migration rate is typically observed for good conductors, therefore by measuring the time dependence of the smoke-ring propagation in this manner for different directions, information on the average horizontal conductivities and subsequent ground anisotropy is provided. In order to test this hypothesis, two locations with different geological conditions were selected. Data were first obtained for a 1-D site, located near Ouyen in northern Victoria, SE Australia, where uniform sedimentary layers dominate the near-surface geology. Additional data were then obtained for two 2-D sites, located close to the Heathcote Fault Zone (central Victoria), where a north–south greenstone belt is responsible for significant lateral anisotropy as observed in previous magnetotelluric (MT) data. Eddy current or smoke-ring expansion rates have subsequently been determined; the results we present here provide the average conductivities along eight axes at each site. A uniform expansion is observed for eddy current systems generated in a 1-D or horizontally layered terrain while strike-dependant distortion is seen for each of the 2-D sites. Hence, static corrections required for MT data in particular, may be further refined using TEM methods to reflect the lateral directional dependence of bulk electrical conductivity.

Post-fire changes in sediment rating curves in a wet Eucalyptus forest in SE Australia

Summary Empirical power law sediment rating curves of the form C = aQb (where C is the sediment concentration, Q is the discharge rate, and the coefficient a and exponent b are fitted parameters), or the alternative form given by log(Qs) = log(a) + (b + 1)log(Q) (where Qs = CQ is the sediment delivery rate, and the natural logarithm is used) are widely used for characterising sediment transport across a broad range of spatial and temporal scales. Fire frequently has a large effect on erosion rates and sediment delivery. We investigate the temporal changes in the coefficient a and exponent b for 3 years following a wildfire between February 2003 and April 2006, for two South Eastern Australian Eucalyptus forested catchments (136 and 244 ha) with mean annual rainfall of 1900 mm. Storm-event integrated sediment loads and discharges were calculated for each of 596 storm events using stage-discharge control structures and in situ turbidity measurements at 15 min intervals. Measurements were converted to sediment concentrations using regression relationships developed from storm activated water auto-samplers. The analysis identified: (i) strong negative linear relationships between the rating coefficient log(a), and the rating exponent b, reflecting sediment rating curves that “pivot” around a common fulcrum point in log–log space, (ii) a systematic shift in this linear relationship between log(a) and b as a function of time since fire, (iii) maximum values of b of ca. 2.5 (i.e. maximum non-linearity in the relationship between discharge and sediment delivery, and therefore maximum sensitivity to high peak-discharge events) immediately following the fire, which decline rapidly and monotonically by a factor of 10 to ca. 0.25 in the first 8 months, attributed to a dominance of hillslope erosion processes and declining rill and interill erodibility, (iv) irregular patterns in the value of b during the vegetation recovery period, probably reflecting a shift from hillslope dominated erosion processes to a greater contribution from channel processes (8–24 months after the fire) and (v) annual cycles in the value of b in the recovered state (24–38 months after the fire) ranging from a minimum of ca. 0.5 in the dry season to a maximum of ca. 1.5 in the wet season. The physical cause of these cycles could not be isolated in this study. The results provide a robust quantitative perspective on the magnitude and temporal variability of the sensitivity of catchments recovering from wildfire.

A review of the Recent Australian species of Merelina Iredale, 1915 (Caenogastropoda: Rissoidae)

The four previously-named Australian species of the rissoid genus Merelina Iredale, 1915 are redescribed and illustrated. A neotype is designated for M. elegans (Angas, 1877) and this species and three others previously named are redescribed and illustrated. In addition, a further four new species are described; M. hirta n. sp. from SE Australia, M. cancellata n. sp. From Bass Strait and Tasmania, M. lordhowensis n. sp. from the islands and seamounts of the southern Lord Howe Rise plateau and M. norfolkensis n. sp. from Norfolk Island. Distributions and revised synonymies are given, along with a key to the Australian species and a list of all the Recent species of the genus.

Out of Their Depth? Isolated Deep Populations of the Cosmopolitan Coral Desmophyllum dianthus May Be Highly Vulnerable to Environmental Change

Deep sea scleractinian corals will be particularly vulnerable to the effects of climate change, facing loss of up to 70% of their habitat as the Aragonite Saturation Horizon (below which corals are unable to form calcium carbonate skeletons) rises. Persistence of deep sea scleractinian corals will therefore rely on the ability of larvae to disperse to, and colonise, suitable shallow-water habitat. We used DNA sequence data of the internal transcribed spacer (ITS), the mitochondrial ribosomal subunit (16S) and mitochondrial control region (MtC) to determine levels of gene flow both within and among populations of the deep sea coral Desmophyllum dianthus in SE Australia, New Zealand and Chile to assess the ability of corals to disperse into different regions and habitats. We found significant genetic subdivision among the three widely separated geographic regions consistent with isolation and limited contemporary gene flow. Furthermore, corals from different depth strata (shallow <600 m, mid 1000–1500 m, deep >1500 m) even on the same or nearby seamounts were strongly differentiated, indicating limited vertical larval dispersal. Genetic differentiation with depth is consistent with the stratification of the Subantarctic Mode Water, Antarctic Intermediate Water, the Circumpolar Deep and North Pacific Deep Waters in the Southern Ocean, and we propose that coral larvae will be retained within, and rarely migrate among, these water masses. The apparent absence of vertical larval dispersal suggests deep populations of D. dianthus are unlikely to colonise shallow water as the aragonite saturation horizon rises and deep waters become uninhabitable. Similarly, assumptions that deep populations will act as refuges for shallow populations that are impacted by activities such as fishing or mining are also unlikely to hold true. Clearly future environmental management strategies must consider both regional and depth-related isolation of deep-sea coral populations.

A novel trap for quantifying the dispersal of seeds by wind

Question: Understanding the aerial movement of seed is of great significance to the management of native and invasive plant species, but has proven difficult to measure. Here we examine how a more quantitative approach to measuring the aerial movement of seed can be achieved. Location: SE Australia. Methods: We describe a novel seed trap (the ‘Melbourne trap’), for which the proportion of free-stream airflow through the trap can be measured, allowing a more quantitative approach to measuring aerial seed movement. We assessed airflow through the Melbourne trap in a wind tunnel and describe how this information, along with measurements of wind speed and direction, can now be used to derive seed density per volume of airflow. We compare the seed capture and retention efficiency of the Melbourne trap with two simpler and cheaper trap designs, bucket traps and sticky traps. Results: Melbourne and bucket traps captured significantly more species than sticky traps. Seed catch was dominated numerically by Lachnagrostis filiformis (G. Forst.) Trin. Melbourne traps proved more effective than sticky traps, but not bucket traps, in capturing L. filiformis, based on intake area. For all other seeds, Melbourne traps were more effective than both bucket and sticky traps. Conclusion: The Melbourne trap design is a significant advance in quantifying seed dispersal by wind. Melbourne traps will improve the capacity and accuracy of studies that seek to: (i) quantify seed fluxes across landscapes boundaries; (ii) assess directionality of dispersal; (iii) understand processes controlling seed release; and (iv) compare dispersal in wind and water.

Relationship between hydraulic and basic properties for irrigated soils in southeast Australia

AbstractThis paper examines the potential of soil maps and spatial information on basic soil properties for predicting soil hydraulic properties in the Shepparton irrigation region (SE Australia). For this purpose, the relationship between locally measured soil hydraulic properties and basic soil properties, and soil categories was analyzed. Pedotransfer functions developed for Australian soil were tested. Furthermore, association of field‐scale final infiltration rates with basic soil properties was investigated. Water‐retention properties, and in particular subsoil water‐retention properties, were significantly correlated with readily available basic soil properties. Spearman's rank correlation coefficients were particularly high for clay content, bulk density, and the sum of exchangeable cations Ca2+, Mg2+, Na+, and K+. Water‐retention properties were adequately predicted using Australian pedotransfer functions. Water‐transmission properties such the saturated conductivity and the final infiltration rate were overall poorly correlated with basic physical and chemical properties. Generally, median water‐transmission properties did not significantly change with soil groups and “within‐paddock variability” accounted for over half of the “within‐soil‐type variability” for many soil types. We concluded that it is feasible to regionalize water‐retention properties for the Shepparton irrigation region using basic physical and chemical soil properties, whereas the information on basic soil properties and from soil maps was insufficient to reliably estimate water‐transmission properties. It is demonstrated why field‐scale estimates of final infiltration rates, obtained by fitting a model for surface irrigation to field measurements of advance, depletion, and recession, may be better correlated with basic soil properties.

Impacts of the New Zealand screwshell Maoricolpus roseus on growth and condition of juvenile commercial scallops Pecten fumatus

The invasion of SE Australia by the exotic New Zealand screwshell Maoricolpus roseus has sparked concern over its potential impact on native soft-sediment assemblages and, in particular, on commercially harvested molluscs. Here we quantify the impact of both live and dead and empty M. roseus shells on the growth, condition and survival of juvenile commercial scallops Pecten fumatus. In a manipulative experiment, P. fumatus juveniles exhibited up to 27% slower linear shell growth, 5% lighter shells (dry weight), 12% less somatic tissue (ash-free dry weight) and 17% poorer condition when caged with live M. roseus. Dead and empty screwshells also reduced scallop growth and condition relative to controls but only at low scallop densities. Scallop mortality did not differ between treatments. The level of impact observed was also dependent on the density of P. fumatus. At low scallop densities, the effects of the invasive M. roseus are largely due to competition for space, as the results from treatments containing live screwshells and those containing dead and empty screwshells were comparable. However, at higher scallop densities, the significant difference between the treatments indicates competition for both space and food. Moreover, comparison between the different scallop densities provides evidence of a combination of both inter- and intraspecific effects. Given the widespread distribution of M. roseus and its occurrence at high densities across large areas of seafloor in SE Australia, impacts on scallop growth and condition have the potential to greatly affect both commercial and recreational scallop fisheries in SE Australia.

CO2CRC Otway project–Soil gas baseline and assurance monitoring 2007–2010

A four-stage soil gas monitoring study was conducted from March 2007 to March 2010 in the western Port Campbell Embayment of the onshore Otway Basin, SE Australia. This study evaluated existing vadose zone soil gases over the CO2CRC Otway Project’s site for CO2 storage, and nearby deep natural CO2 accumulations. Carbon dioxide, methane and helium were the main gases analysed and much of the time CH4 concentrations were too low for accurate analysis. Carbon dioxide concentrations ranged from atmospheric background levels of 0.033% up to about 10% of the total soil gas. The δ13CCO2 values are typical for organic matter decomposition as the main source of the CO2 in the soil gas. Modern radiocarbon ages, determined from 14C analysis, and low helium concentrations support the conclusion that CO2 in the soil gas is predominantly from modern organic sources. There was a relative increase in CO2 concentration measured in locations where the Port Campbell Limestone is near the ground surface, which implies additional CO2 has been produced from the weathering of limestone.

Terra Preta Australis: Reassessing the carbon storage capacity of temperate soils

Soils developed on the sites of Australian Aboriginal oven mounds along the Murray River in SE Australia, classified as Cumulic Anthroposols under the Australian Soil Classification, are shown to have traits similar to the Terra Preta de Indio of the Amazon basin. Seven such sites were characterised and compared with adjacent soils. The Cumulic Anthroposols contained significantly (p<0.05) more soil carbon (C), compared to adjacent non-Anthroposols. Solid-state 13C NMR spectroscopy showed that the C in the Cumulic Anthroposols was predominantly aromatic, especially at depth, confirming the presence of charcoal. Radiocarbon analysis carried out on charcoal collected from two of these sites showed that it was deposited 650±30 years BP at one site and 1609±34 years BP at the other site, demonstrating its recalcitrance in soil. The charcoal originated from plant material, as shown by SEM, and had high levels of Ca agglomeration on its surfaces. The Cumulic Anthroposols were shown to have altered nutrient status, with total N, P, K and Ca being significantly greater than in the adjacent soils throughout the profile. This was also reflected in the higher mean CEC of 31.2cmol (+)kg−1 and higher pH by 1.3 units, compared to the adjacent soils. Based on the similarity of these Cumulic Anthroposols with the Terra Preta de Indio of the Amazon, we suggest that these Cumulic Anthroposols can be classified as Terra Preta Australis. The existence of these soils demonstrates that Australian soils, in temperate climates, are capable of storing C in much higher quantities than has been previously recognised, and that this capability is founded on the unique stability and properties of charred organic matter. Furthermore, the addition of charcoal appears to have improved the physical and chemical properties of these soils. Together, this provides important support for the concept of soil amendment with “biochar”, the charred residue produced by pyrolysis of biomass, as a means for sequestering C and enhancing agricultural productivity.

Reproduction and ontogeny of Mastacomys fuscus (Rodentia: Muridae) in the Australian Alps and comparisons with other small mammals living in alpine communities

Two species of small rodents, Mastacomys fuscus and Rattus fuscipes, and one small dasyurid marsupial Antechinus swainsonii live sympatrically in the subalpine habitat of SE Australia. This paper describes the reproductive characteristics and ontogeny of M. fuscus, and shows that the three species have different reproductive strategies that, in part, are a reflection of their different phylogenies. Cold and snow in winter, and a short summer season, limit the length of time available for reproduction and development. The rodent species exhibit similar reproductive characteristics to those in alpine regions of Europe, North America and South Africa.

Arc–continent collision and orogenesis in western Tasmanides: Insights from reactivated basement structures and formation of an ocean–continent transform boundary off western Tasmania

Crustal architecture in formerly contiguous basement terranes in SE Australia, Tasmania and northern Victoria Land is a legacy of late Neoproterozoic–Cambrian subduction-related processes, culminating in formation of the Delamerian–Ross orogen. Structures of Delamerian–Ross age were subsequently reactivated during late Mesozoic–Cenozoic Gondwana breakup, strongly influencing the geometry of continental rifting and providing clues about the origins and configuration of the pre-existing basement structures. An ocean–continent transform boundary developed off western Tasmania follows the trace of an older Paleozoic strike-slip structure (Avoca–Sorell fault system) optimally oriented for reactivation during the final separation of Australia from Antarctica. This boundary cuts across rocks preserving an earlier record of arc–continent collision during the course of which continental crust was subducted to mantle depths and Cambrian mafic–ultramafic island arc rocks were thrust westwards over late Neoproterozoic–Cambrian passive margin sequences. Collision was accompanied by development of a foreland basin into which 520–600 Ma arc-derived detrital zircons were shed. Following a reversal in subduction polarity, and change to transcurrent motion along the Gondwana margin, Tasmania migrated northward along the proto-Avoca fault system before entering a subduction zone located along the Heathcote–Governor fault system, precipitating a second collision, south-vergent thrusting, and tectonic reworking of the already accreted Cambrian arc–forearc assemblages and underlying passive margin sequences.

Exotic crustal block accretion to the eastern Gondwanaland margin in the Late Cambrian–Tasmania, the Selwyn Block, and implications for the Cambrian–Silurian evolution of the Ross, Delamerian, and Lachlan orogens

Reconstructions of the Cambrian–Silurian tectonic evolution of eastern Gondwanaland, when the Australian Tasmanides and Antarctic Ross Orogen developed, rely on correlation between structural elements in SE Australia and Northern Victoria Land (NVL), Antarctica. A variety of published models exist but none completely solve the tectonic puzzle that is the Delamerian–Lachlan transition in the Tasmanides. This paper summarizes the understanding of Cambrian (Delamerian) to Silurian (Lachlan) geological evolution of the eastern Tasmanides, taking into account new deep seismic data that clarifies the geological connection between Victoria and Tasmania — the ‘Selwyn Block’ model. It evaluates previous attempts at correlation between NVL, Tasmania and Victoria, and presents a new scenario that encompasses the most robust correlations. Tasmania together with the Selwyn Block is reinterpreted as an exotic Proterozoic microcontinental block – ‘VanDieland’ – that collided into the east Gondwanaland margin south of western Victoria, and north of NVL in the Late Cambrian, perhaps terminating the Delamerian Orogeny in SE Australia. Subsequent north-east ‘tectonic escape’ of VanDieland in the Early Ordovician explains the present-day outboard position of Tasmania with respect to the rest of the Delamerian orogen, the origin of the hiatus that separates the Delamerian and Lachlan orogenic cycles in Australia, and how western Lachlan oceanic crust developed as a ‘trapped plate-segment’. The model establishes a new structural template for subsequent Lachlan Orogen development and Mesozoic Australia–Antarctica separation.

Juncus bulbosusf.submucronatus(Juncaceae), a New Taxon from Europe, Australia, Canada, Chile, Azores and Morocco

The paper describes a new taxon, Juncus bulbosus f. submucronatus J. Proćków, designates an epitype for J. bulbosus L. f. bulbosus, and details the distribution of both forms. The new form is native to most of Europe, NW Africa and Azores, and introduced to E Canada, SE Australia and S Chile. It is more frequent in western, central (excluding Poland) and southern Europe, contrary to f. bulbosus which is more common in northern Europe (excluding Iceland and Faroe Islands) and in Poland. A detailed key to all the infraspecific taxa of J. bulbosus is given. The new taxon differs from its closest relatives by the presence of dorsal (i.e. localised just below the apices of perianth segments) mucros usually pronouncedly or at least distinctly exceeding the perianth tops. The chromosome number for the new taxon (2n = 40) and ecological differences between the forms are given. In Poland f. submucronatus grows in eutrophic ponds and f. bulbosus thrives in oligotrophic Lobelia lakes.

Using AEM data as part of an Integrated Assessment of the Salinity Hazard and Risk to Gunbower State Forest and the River Murray Floodplain in the Gunbower Island-Barr Creek reach of the Murray River, SE Australia.

Using AEM data as part of an Integrated Assessment of the Salinity Hazard and Risk to Gunbower State Forest and the River Murray Floodplain in the Gunbower Island-Barr Creek reach of the Murray River, SE Australia.