Complexation of copper by sewage sludge-derived dissolved organic matter: Effects on soil sorption behaviour and plant uptake

The complexation of Cu by sewage sludge-derived dissolved organic matter (SSDOM) is a process by which the environmental significance of the element may become enhanced due to reduced soil sorption and, hence, increased mobility. The work described in this paper used an ion selective electrode procedure to show that SSDOM complexation of Cu was greatest at intermediate pH values because competition between hydrogen ions and Cu for SSDOM binding sites, and between hydroxyl ions and SSDOM as Cu ligands, was lowest at such values. Batch sorption experiments further showed that the process of Cu complexation by SSDOM provided an explanation for enhanced desorption of Cu from the solid phase of a contaminated, organic matter-rich, clay loam soil, and reduced adsorption of Cu onto the solid phase of a sandy loam soil. Complexation of Cu by SSDOM did not affect uptake of Cu by spring barley plants, when compared to free ionic Cu, in a sand-culture pot experiment. However, it did appear to lead to greater biomass yields of the plant; perhaps indicating that the Cu-SSDOM complex had a lower toxicity towards the plant than the free Cu ion.

Influence of dissolved organic matter on the solubility of heavy metals in sewage-sludge-amended soils

Sewage-sludge-amended soils generally contain elevated levels of organic matter and heavy metals compared to control soils. Because organic matter is known to complex with heavy metals, the solubility behavior of the organic matter in such soils may exert a significant influence on the solubility of the metals. Little is known about such a process. Using batch experiments in which the solubility of organic matter in a heavily sludge-amended soil was artificially manipulated, we show that the solubilities of the heavy metals copper (Cu), nickel (Ni), and lead (Pb) show a strong positive relationship to the solubility of organic matter, particularly at high pH. The results suggest that under field conditions, spatiotemporal variations in the solid-solution partitioning of organic matter may have a bearing on the environmental significance (mobility and bioavailability) of these heavy metals.

The role of biotic and abiotic factors in evolution of ant dispersal in the milkwort family (Polygalaceae)

A phylogenetic approach was taken to investigate the evolutionary history of seed appendages in the plant family Polygalaceae (Fabales) and determine which factors might be associated with evolution of elaiosomes through comparisons to abiotic (climate) and biotic (ant species number and abundance) timelines. Molecular datasets from three plastid regions representing 160 species were used to reconstruct a phylogenetic tree of the order Fabales, focusing on Polygalaceae. Bayesian dating methods were used to estimate the age of the appearance of ant-dispersed elaiosomes in Polygalaceae, shown by likelihood optimizations to have a single origin in the family. Topology-based tests indicated a diversification rate shift associated with appearance of caruncular elaiosomes. We show that evolution of the caruncular elaiosome type currently associated with ant dispersal occurred 54.0-50.5 million year ago. This is long after an estimated increase in ant lineages in the Late Cretaceous based on molecular studies, but broadly concomitant with increasing global temperatures culminating in the Late Paleocene-Early Eocene thermal maxima. These results suggest that although most major ant clades were present when elaiosomes appeared, the environmental significance of elaiosomes may have been an important factor in success of elaiosome-bearing lineages. Ecological abundance of ants is perhaps more important than lineage numbers in determining significance of ant dispersal. Thus, our observation that elaiosomes predate increased ecological abundance of ants inferred from amber deposits could be indicative of an initial abiotic environmental function.

Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes - a genome comparison

The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a range of biochemical functions including photosynthesis, induction of root nodules and symbiotic nitrogen fixation and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance. Some isolates of Bradyrhizobium have been shown to be non-symbiotic and do not possess the ability to form nodules. Here we present the genome and gene annotations of two such free-living Bradyrhizobium isolates, named G22 and BF49, from soils with differing long-term management regimes (grassland and bare fallow respectively) in addition to carbon metabolism analysis. These Bradyrhizobium isolates are the first to be isolated and sequenced from European soil and are the first free-living Bradyrhizobium isolates, lacking both nodulation and nitrogen fixation genes, to have their genomes sequenced and assembled from cultured samples. The G22 and BF49 genomes are distinctly different with respect to size and number of genes; the grassland isolate also contains a plasmid. There are also a number of functional differences between these isolates and other published genomes, suggesting that this ubiquitous genus is extremely heterogeneous and has roles within the community not including symbiotic nitrogen fixation.

Building Nature’s Safety Net 2014 : A decade of protected area achievements in Australia

The single most important asset for the conservation of Australia’s unique and globally significant biodiversity is the National Reserve System, a mosaic of over 10,000 discrete protected areas on land on all tenures: government, Indigenous and private,including on-farm covenants, as well as state, territory and Commonwealth marine parks and reserves.THE NATIONAL RESERVE SYSTEMIn this report, we cover major National Reserve System initiatives that have occurred in the period 2002 to the present and highlight issues affecting progress toward agreed national objectives. We define a minimum standard for the National Reserve System to comprehensively, adequately and representatively protect Australia’s ecosystem and species diversity on sea and land. Using government protected area, species and other relevant spatial data, we quantify gaps: those areas needing to move from the current National Reserve System to one which meets this standard. We also provide new estimates of financial investments in protected areas and of the benefits that protected areas secure for society. Protected areas primarily serve to secure Australia’s native plants and animals against extinction, and to promote their recovery.BENEFITSProtected areas also secure ecosystem services that provide economic benefits forhuman communities including water, soil and beneficial species conservation, climatemoderation, social, cultural and health benefits. On land, we estimate these benefitsare worth over $38 billion a year, by applying data collated by the Ecosystem ServicesPartnership. A much larger figure is estimated to have been secured by marineprotected areas in the form of moderation of climate and impact of extreme eventsby reef and mangrove ecosystems. While these estimates have not been verified bystudies specific to Australia, they are indicative of a very large economic contributionof protected areas. Visitors to national parks and nature reserves spend over $23.6 billion a year in Australia, generating tax revenue for state and territory governments of $2.36 billion a year. All these economic benefits taken together greatly exceed the aggregate annual protected area expansion and management spending by all Australian governments, estimated to be ~$1.28 billion a year. It is clear that Australian society is benefiting far greater than its governments’ investment into strategic growth and maintenance of the National Reserve System.Government investment and policy settings play a leading role in strategic growth of the National Reserve System in Australia, and provide a critical stimulus fornon-government investment. Unprecedented expansion of the National Reserve System followed an historic boost in Australian Government funding under Caring for Our Country 2008–2013. This expansion was highly economical for the Australian Government, costing an average of only $44.40 per hectare to buy and protect land forever. State governments have contributed about six times this amount toward the expansion of the National Reserve System, after including in-perpetuity protected area management costs. The growth of Indigenous Protected Areas by the Australian Government has cost ~$26 per hectare on average, including management costs capitalised in-perpetuity, while also delivering Indigenous social and economic outcomes. The aggregate annual investment by all Australian governments has been ~$72.6 million per year on protected area growth and ~$1.21 billion per year on recurrent management costs. For the first time in almost two decades, however, the Australian Government’s National Reserve System Program, comprising a specialist administrative unit and funding allocation, was terminated in late 2012. This program was fundamental in driving significant strategic growth in Australia’s protected area estate. It is highly unlikely that Australia can achieve its long-standing commitments to an ecologically representative National Reserve System, and prevent major biodiversity loss, without this dedicated funding pool. The Australian Government has budgeted ~$400 million per year over the next five years (2013-2018) under the National Landcare and related programs. This funding program should give high priority to delivery of national protected area commitments by providing a distinct National Reserve System funding allocation. Under the Convention on Biological Diversity (CBD), Australia has committed to bringing at least 17 percent of terrestrial and at least 10 per cent of marine areas into ecologically representative, well-connected systems of protected areas by 2020 (Aichi Target 11).BIODIVERSITY CONSERVATIONAustralia also has an agreed intergovernmental Strategy for developing a comprehensive, adequate and representative National Reserve System on land andsea that, if implemented, would deliver on this CBD target. Due to dramatic recent growth, the National Reserve System covers 16.5 per cent of Australia’s land area, with highly protected areas, such as national parks, covering 8.3 per cent. The marine National Reserve System extends over one-third of Australian waters with highly protected areas such as marine national parks, no-take or green zones covering 13.5 per cent. Growth has been uneven however, and the National Reserve System is still far from meeting Aichi Target 11, which requires that it also be ecologically representative and well-connected. On land, 1,655 of 5,815 ecosystems and habitats for 138 of 1,613 threatened species remain unprotected. Nonetheless, 436 terrestrial ecosystems and 176 threatened terrestrial species attained minimum standards of protection due to growth of the National Reserve System on land between 2002 and 2012. The gap for ecosystem protection on land – the area needed to bring all ecosystems to the minimum standard of protection – closed by a very substantial 20 million hectares (from 77 down to 57 million hectares) between 2002 and 2012, not including threatened species protection gaps. Threatened species attaining a minimum standard for habitat protection increased from 27 per cent to 38 per cent over the decade 2002–2012. A low proportion of critically endangered species meeting the standard (29 per cent) and the high proportion with no protection at all (20 per cent) are cause for concern, but one which should be relatively easy to amend, as the distributions of these species tend to be small and localised. Protected area connectivity has increased modestly for terrestrial protected areas in terms of the median distance between neighbouring protected areas, but this progress has been undermined by increasing land use intensity in landscapes between protected areas.A comprehensive, adequate and representative marine reserve system, which meetsa standard of 15 per cent of each of 2,420 marine ecosystems and 30 per cent of thehabitats of each of 177 marine species of national environmental significance, wouldrequire expansion of marine national parks, no-take or green zones up to nearly 30per cent of state and Australian waters, not substantially different in overall extentfrom that of the current marine reserve system, but different in configuration.Protection of climate change refugia, connectivity and special places for biodiversityis still low and requires high priority attention. FINANCING TO FILL GAPS AND MEET COMMITMENTSIf the ‘comprehensiveness’ and ‘representativeness’ targets in the agreed terrestrial National Reserve System Strategy were met by 2020, Australia would be likely to have met the ‘ecologically representative’ requirement of Aichi Target 11. This would requireexpanding the terrestrial reserve system by at least 25 million hectares. Considering that the terrestrial ecosystem protection gap has closed by 20 million hectares over the past decade, this required expansion would be feasible with a major boost in investment and focus on long-standing priorities. A realistic mix of purchases, Indigenous Protected Areas and private land covenants would require an Australian Government National Reserve System investment of ~$170 million per year over the five years to 2020, representing ~42 per cent of the $400 million per year which the Australian Government has budgeted for landcare and conservation over the next five years. State, territory and local governments, private and Indigenous partners wouldlikewise need to boost financial commitments to both expand and maintain newprotected areas to meet the agreed National Reserve System strategic objectives.The total cost of Australia achieving a comprehensive, adequate and representativemarine reserve system that would satisfy Aichi Target 11 is an estimated $247 million.

Meroplankton in the Kara Sea

Meroplankton was sampled at 11 stations in the southern Kara Sea and the Yenisei Estuary in September 2000. Larvae of 29 benthic taxa representing 10 higher groups were identified. Meroplankton was present at almost all stations and most depth levels. The two most abundant groups were Echinodermata (68%) and Polychaeta (26%). Echinoderms dominated total meroplankton locally due to mass occurrences of Ophiopluteus larvae. The relative group composition was highly variable and seemed to depend mainly on the local hydrographic pattern. Comparison of meroplanktonic data with the distribution of the adults revealed for Spionida and Bivalvia a 'downstream' transport of the larvae whereas for other polychaete species and Ophiuroida 'upstream' transport into the estuary occurred. The distribution and concentration of the larvae within the estuary is explained by physical barriers established by hydrographic gradients, the prevailing mixing processes and the presence of a near-bottom counter current.

Paleogene and Neogene larger foraminifera of ODP Leg 133 holes

At several sites drilled during Ocean Drilling Program (ODP) Leg 133 on the Queensland Plateau, larger shallow-water benthic foraminifers have been recovered from neritic carbonates and from turbidites that consist of shallow-water-derived material. Within neritic sediments, the occurrence of different faunal associations provides a tool for biostratigraphic subdivision. Three main phases of neritic deposition occurred on the Queensland Plateau. An Eocene episode is characterized by subtropical to temperate associations (Operculina-Nummulites Facies). It is unconformably followed by a late Oligocene to middle Miocene episode that contains tropical to subtropical associations (Spiroclypeus Facies, Larger Foraminifer-Coral Facies, Austrotrillina Facies, Flosculinella-Amphistegina Facies, Marginopora Facies, and Miogypsina Facies). After the middle Miocene, most of the Queensland Plateau carbonate platform was drowned. The post-middle Miocene to Holocene reefs, which are characterized by a geographically more restricted distribution, shed neritic material including larger benthic foraminifers into adjacent basinal areas. This process is associated with a partial reworking of middle Miocene deposits containing Lepidocyclina (Nephrolepidina).

Biomarkers in surface sediments from the Ob and Yenisei estuaries and the southern Kara Sea

Organic-geochemical bulk parameter (Total organic carbon contents, C/N ratios and d13Corg values), biogenic opal and biomarkers (n-alkanes, fatty acids, sterols and amino acids) were determined in surface sediments from the Ob and Yenisei estuaries and the adjacent southern Kara Sea. Maximum TOC contents were determined in both estuaries, reaching up to 3 %. Relatively high C/N ratios around 10, light d13Corg values of -26.5 per mil (Yenisei) and -28 to -28.7 per mil (Ob), and maximum concentrations of long-chain n-alkanes of up to about 10 µg/g Sed clearly show the predominance of terrigenous organic matter in the sediments from the estuaries. Towards the open Kara Sea, all p arameters indicate a decrease in terrigenous organic carbon. Brassicasterol as well as the short-chain n-alkanes parallel this trend, suggesting that these biomarkers are probably also related to a terrigenous (fresh-water phytoplankton) source. Amino acid spectra show characteristic trends from the Yenisei Estuary to the open Kara Sea revealing increasing state of degradation. Sedimentary organic matter in the Yenisei Estuary is relatively less degraded compared to the Ob Estuary and the open Kara Sea.

Chemostratigraphy (CaCO3, TOC, d13Corg) of Sinemurian black shales

The Shales-with-'Beef' and Black Ven Marls of the Charmouth Mudstone Formation (Sinemurian) exposed on the Dorset Coast in southern England (Wessex Basin) show stratigraphic variation in carbonate, organic carbon and organic-carbon isotopes. Little environmental significance is attached to the variation of carbonate except in the case of the tabular and nodular limestones interrupting the sequence that probably record stratigraphic condensation and/or sedimentary stillstands that, in an extreme case, were accompanied by sea-floor erosion to produce the bored and encrusted 'Coinstone'. Relatively high total organiccarbon (TOC) contents are present in the laminated mudstones of the lower turneri Zone (upper brooki and lower birch Subzones) and the obtusum Zone (obtusum and stellare Subzones). Basin stratification related to fresh-water influx was the most likely aid to deoxygenation and enhanced preservation of organic matter. The organic-carbon isotope curve (d13Corg), which shows positive excursions in the upper turneri Zone (upper birchi Subzone) and highest obtusum - raricostatum Zones (highest stellare Subzone, densinodulum and lower raricostatoides Subzones), does not correlate with the TOC stratigraphy and was clearly not controlled by local patterns of organic-matter burial. Long-term (hundreds-of-thousands of years) variations in the carbon-isotope (d13Corg) curve are interpreted as reflecting changing seawater isotopic composition and, in the case of the stratigraphically higher interval, may be related to marine organic-carbon burial on the margins of the proto-Atlantic, as exemplified by the Lusitanian Basin in Portugal. Correlation of the carbon-isotope profile with putative sea-level curves is problematic in detail, although significant local transgressive pulses in the turneri and late raricostatum Zones are approximately coincident with positive d13Corg excursions.