The oribatid mite superfamily Eutegaeoidea (Acari, Oribatida), with descriptions of new taxa from Australia and New Caledonia and a re-assessment of genera and families.

Twenty-four new species of Eutegaeoidea from Australia and New Caledonia are described, and two new genera are proposed. These are Eutegaeus woiwurrung sp. nov., E. nothofagi sp. nov., E. bidhawal sp. nov., E. ptilosus sp. nov., Humerotegaeus carinatus gen. et sp. nov., H. concentricus gen. et sp. nov., Atalotegaeus crobylus sp. nov., Neoeutegaeus torsteini sp. nov., N. melipsilon sp. nov. N. malcolmi sp. nov., N. corniculatus sp. nov. (Eutegaeidae), Compactozetes goongerah sp. nov., C. crenellatus sp. nov. (Compactozetidae) and Pterozetes lawrencei sp. nov. (Pterozetidae) from temperate rainforests in Victoria and Tasmania; Compactozetes bundjalung sp. nov., C. calderi sp. nov., C. duonodulus sp. nov., Sadocepheus remus sp. nov. (Compactozetidae) and Porrhotegaeus githabul sp. nov. (Porrhotegaeidae fam. nov.) from temperate and sub-tropical rainforests of the Great Dividing Range in central and northern New South Wales and southern Queensland, Porrhotegaeus catherinae sp. nov. from scalybark closed forest on Lord Howe Island, Eutegaeus odontatus sp. nov. and Compactozetes pirumorpha sp. nov. from moist upland forest on Norfolk Island and Neseutegaeus wardi sp. nov. and Atalotegaeus deficiens sp. nov. from tropical rainforest and moss forest in New Caledonia. Based on the predominantly Southern Hemisphere distribution of Eutegaeoidea, indicating strong Gondwanan affinities, and the morphology of adults and immatures, this taxon is treated as distinct from the Cepheoidea which has a distribution almost entirely within the Northern Hemisphere. Eutegaeoid species previously described from Australia (Eutegaeus soror P. Balogh, 1985, Atalotegaeus mensarosi J. & P. Balogh, 1983, Neseutegaeus monteithi J. & P. Balogh, 1983, Neoeutegaeus phyllophorus J. & P. Balogh, 1983 and Porrhotegaeus ornatus J. Balogh & Mahunka, 1966) are redescribed based on type material and new distribution records provided. Species have distribution patterns predominantly indicative of short-range endemics associated with remnant Gondwanan rainforest. Neseutegaeus monteithi is recombined with Atalotegaeus Luxton, 1988a. The definitions of genera and families of Eutegaeoidea are revised, and their relationships are reconsidered. Birotegaeus Luxton, 1988a and Pareutegaeus Woolley, 1965 are designated junior synonyms of Eutegaeus Berlese, 1916. Immatures are described for the genera Atalotegaeus, Eutegaeus, Neoeutegaeus Aoki, 1964 and Porrhotegaeus J. Balogh & Mahunka, 1966. Neoeutegaeidae fam. nov. is established for Neoeutegaeus Aoki, 1964 and Humerotegaeus gen. nov., Porrhotegaeidae fam. nov. for Porrhotegaeus and Bornebuschiidae fam. nov. for Bornebuschia Hammer, 1966 and Dicrotegaeus Luxton, 1988 which had previously been placed in Cerocepheidae or Compactozetidae. Eutegaeus aysenensis Ermilov, 2021 and E. queulatensis Ermilov, 2021 from Chile, are recombined with Atalotegaeus. A key is provided to the genera of the eight families of Eutegaeoidea, as recognised herein: Eutegaeidae, Neoeutegaeidae fam. nov., Cerocepheidae, Compactozetidae, Bornebuschiidae fam. nov., Pterozetidae and Porrhotegaeidae fam. nov.

The Dammed and the Saved: a Conservation Triage Framework for Wetlands under Climate Change in the Murray-Darling Basin, Australia.

As the impacts of climate change and water demands from irrigation continue to increase in the Murray-Darling Basin, water for the environment is becoming more scarce and the ecological conditions of many wetlands is poor. With water scarcity, conservation triage is becoming an increasingly relevant management option for environmental watering of wetlands. However, triage is controversial; being considered contrary to current conservation objectives and practices. We assessed environmental watering at two Ramsar wetlands, Macquarie Marshes and Gunbower Forest, based on international environmental treaty obligations and domestic policy settings, changes to flow regimes, wetland condition and current management. Triage decision making was found to be in tacit use at Macquarie Marshes, based on 'rules of thumb' and experiential ecohydrological knowledge, whereas formal environmental watering planning formed the basis for triage decision making at Gunbower Forest. We developed a framework for conservation triage of wetlands in the Murray-Darling Basin to stimulate change in the decision context for wetland conservation and adaptation under climate change. Conservation triage entails reframing of relationships between people and nature and values, rules and knowledge used by stakeholders. Because water is the medium by which wetland conservation outcomes eventuate, trade-offs between competing water uses can be realised with the triage framework.

Trees as brokers in social networks: Cascades of rights and benefits from a Cultural Keystone Species.

Indigenous trees play key roles in West African landscapes, such as the néré tree (Parkia biglobosa (Jacq.) R.Br. ex G.Don). We applied social-ecological network analysis to understand the social-ecological interactions around néré. We documented the benefits néré provides and the multiple social interactions it creates amongst a large range of actors. The flows of rights over the trees and benefits from them formed two hierarchical networks, or cascades, with different actors at the top. The two forms of power revealed by the two cascades of rights and benefits suggest possible powers and counter-powers across gender, ethnicity, and age. We documented how the tree catalyses social interactions across diverse groups to sustain vital social connections, and co-constitute places, culture, and relationships. We argue that a paradigm shift is urgently needed to leverage the remarkable untapped potential of indigenous trees and Cultural Keystone Species in current global restoration and climate change agendas.

First records of Tumerozetidae and Nodocepheidae from Australia, with descriptions of new taxa and a re-assessment of the Polypterozetoidea (Oribatida, Brachypylina).

New species and a new genus of polypterozetoid oribatid mite are described from wet habitats in forests in south-eastern Australia: Tumerozetes roughleyi sp. nov. (Tumerozetidae), Nodocepheus luxtoni sp. nov. and Sacculella yarra gen. et sp. nov. (Nodocepheidae). The superfamily Polypterozetoidea has not been recorded previously from Australia. Tumerozetes roughleyi sp. nov. and Sacculella yarra gen. et sp. nov. were recorded from temperate Nothofagus cunninghami rainforest in central Victoria. Nodocepheus luxtoni sp. nov. was recorded from temperate rainforest in Tasmania and eastern Victoria. Tumerozetes was known previously only from New Zealand, and Nodocepheus from New Zealand, southern Africa and south-central America. The definitions of Tumerozetidae and Nodocepheidae are revised in the light of observations on the morphology of these new species, and their phylogenetic and biogeographical affinities with other members of the Polypterozetoidea are considered.

Co-producing ecosystem services for adapting to climate change.

Ecosystems can sustain social adaptation to environmental change by protecting people from climate change effects and providing options for sustaining material and non-material benefits as ecological structure and functions transform. Along adaptation pathways, people navigate the trade-offs between different ecosystem contributions to adaptation, or adaptation services (AS), and can enhance their synergies and co-benefits as environmental change unfolds. Understanding trade-offs and co-benefits of AS is therefore essential to support social adaptation and requires analysing how people co-produce AS. We analysed co-production along the three steps of the ecosystem cascade: (i) ecosystem management; (ii) mobilization; and (iii) appropriation, social access and appreciation. Using five exemplary case studies across socio-ecosystems and continents, we show how five broad mechanisms already active for current ecosystem services can enhance co-benefits and minimize trade-offs between AS: (1) traditional and multi-functional land/sea management targeting ecological resilience; (2) pro-active management for ecosystem transformation; (3) co-production of novel services in landscapes without compromising other services; (4) collective governance of all co-production steps; and (5) feedbacks from appropriation, appreciation of and social access to main AS. We conclude that knowledge and recognition of co-production mechanisms will enable pro-active management and governance for collective adaptation to ecosystem transformation. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.

The oribatid mite genus Topalia in Australia (Oribatida: Nosybeidae) and the taxonomic status of related families and genera.

Five new species of Topalia (Nosybeidae) are described from Australia: Topalia caliginosa sp. nov. from Victoria, T. corinnensis sp. nov. from Tasmania, T. dunlopi sp. nov. and T. katyae sp. nov. from Norfolk Island and T. royi sp. nov. from New South Wales. The genus was known previously from Australia from unidentified specimens only. I revise the generic definition, provide a key to species and clarify the family placement and taxonomic status of Topalia, Nosybea, Lamellocepheus and Charassobates. From a phylogenetic analysis and identification of synapomorphies, I consider Topalia, Nosybea and Lamellocepheus are valid, morphologically related and included in the Nosybeidae. The superfamily Charassobatoidea is valid, and contains Charassobatidae, Nosybeidae and Microtegeidae. These families have synapomorphies of a narrow, elongate subcapitulum, minute notogastral setae with at least one pair in the d series retained in the adults (dm in Nosybeidae, dp or dm in Microtegeidae, full complement in Charassobates). Immatures of Nosybeidae and Microtegeidae are undescribed, but in Charassobates are eupheredermous, plicate, and the tritonymph has the full complement of setae in the d series. Charassobates and Topalia have the synapomorphy of a ventral plate tectum, providing strong evidence for their relatedness. By way of contrast, the Cepheoidea, in which Nosybeidae and Microtegeidae have been placed by various authors, have a broad subcapitulum, well-developed setiform notogastral setae positioned marginally and lacking the d series, and no ventral plate tectum. The immatures are eupheredermous but non-plicate and the tritonymph lacks setae in the d series. Based on these differences, Nosybeidae, Microtegeidae and Charassobatidae cannot be included in the Cepheoidea.

Contrasting diversity patterns of breeding Anatidae in the Northern and Southern Hemispheres.

For sustaining ecosystem functions and services, environmental conservation strategies increasingly target to maintain the multiple facets of biodiversity, such as functional diversity (FD) and phylogenetic diversity (PD), not just taxonomic diversity (TD). However, spatial mismatches among these components of biodiversity can impose challenges for conservation decisions. Hence, understanding the drivers of biodiversity is critical. Here, we investigated the global distribution patterns of TD, FD, and PD of breeding Anatidae. Using null models, we clarified the relative importance of mechanisms that influence Anatidae community. We also developed random forest models to evaluate the effects of environmental variables on the Anatidae TD, FD, and PD. Our results showed that geographical variation in Anatidae diversity is hemispheric rather than latitudinal. In the species-rich Northern Hemisphere (NH), the three diversity indices decreased with latitude within the tropical zone of the NH, but increased in the temperate zone reaching a peak at 44.5-70.0°N, where functional and phylogenetic clustering was a predominant feature. In the Southern Hemisphere (SH), Anatidae diversity increased poleward and a tendency to overdispersion was common. In NH, productivity seasonality and temperature in the coldest quarter were the most important variables. Productivity seasonality was also the most influential predictor of SH Anatidae diversity, along with peak productivity. These findings suggested that seasonality and productivity, both consistent with the energy-diversity hypothesis, interact with the varying histories to shape the contrasting hemispheric patterns of Anatidae diversity. Phylogenetic diversity (PD) and FD underdispersion, widespread across the species-rich, seasonally productive mid-to-high latitudes of the NH, reflects a rapid evolutionary radiation and resorting associated with Pleistocene cycles of glaciation. The SH continents (and southern Asia) are characterized by a widespread tendency toward PD and FD overdispersion, with their generally species-poor communities comprising proportionately more older lineages in thermally more stable but less predictably productive environments.

Reducing risks by transforming landscapes: Cross-scale effects of land-use changes on ecosystem services.

Globally, anthropogenic environmental change is exacerbating the already vulnerable conditions of many people and ecosystems. In order to obtain food, water, raw materials and shelter, rural people modify forests and other ecosystems, affecting the supply of ecosystem services that contribute to livelihoods and well-being. Despite widespread awareness of the nature and extent of multiple impacts of land-use changes, there remains limited understanding of how these impacts affect trade-offs among ecosystem services and their beneficiaries across spatial scales. We assessed how rural communities in two forested landscapes in Indonesia have changed land uses over the last 20 years to adapt their livelihoods that were at risk from multiple hazards. We estimated the impact of these adaptation strategies on the supply of ecosystem services by comparing different benefits provided to people from these land uses (products, water, carbon, and biodiversity), using forest inventories, remote sensing, and interviews. Local people converted forests to rubber plantations, reforested less productive croplands, protected forests on hillsides, and planted trees in gardens. Our results show that land-use decisions were propagated at the landscape scale due to reinforcing loops, whereby local actors perceived that such decisions contributed positively to livelihoods by reducing risks and generating co-benefits. When land-use changes become sufficiently widespread, they affect the supply of multiple ecosystem services, with impacts beyond the local scale. Thus, adaptation implemented at the local-scale may not address development and climate adaptation challenges at regional or national scale (e.g. as part of UN Sustainable Development Goals or actions taken under the UNFCCC Paris Agreement). A better understanding of the context and impacts of local ecosystem-based adaptation is fundamental to the scaling up of land management policies and practices designed to reduce risks and improve well-being for people at different scales.

Researchers must be aware of their roles at the interface of ecosystem services science and policy.

Scientists working on ecosystem service (ES) science are engaged in a mission-driven discipline. They can contribute to science-policy interfaces where knowledge is co-produced and used. How scientists engage with the governance arena to mobilise their knowledge remains a matter of personal choice, influenced by individual values. ES science cannot be considered neutral and a discussion of the values that shape it forms an important part of the sustainability dialogue. We propose a simple decision tree to help ES scientists identify their role and the purpose of the knowledge they produce. We characterise six idealised scientific postures spanning possible roles at the science-policy interface (pure scientist, science arbiter-guarantor, issue advocate-guardian, officer, honest broker and stealth issue advocate) and illustrate them with feedbacks from interviews. We encourage ES scientists to conduct a reflexive exploration of their attitudes regarding knowledge production and use, with the intention of progressing toward a higher recognition of the political and ethical importance of ES assessments.

Transforming conservation science and practice for a postnormal world.

We examine issues to consider when reframing conservation science and practice in the context of global change. New framings of the links between ecosystems and society are emerging that are changing peoples' values and expectations of nature, resulting in plural perspectives on conservation. Reframing conservation for global change can thus be regarded as a stage in the evolving relationship between people and nature rather than some recent trend. New models of how conservation links with transformative adaptation include how decision contexts for conservation can be reframed and integrated with an adaptation pathways approach to create new options for global-change-ready conservation. New relationships for conservation science and governance include coproduction of knowledge that supports social learning. New processes for implementing adaptation for conservation outcomes include deliberate practices used to develop new strategies, shift world views, work with conflict, address power and intergenerational equity in decisions, and build consciousness and creativity that empower agents to act. We argue that reframing conservation for global change requires scientists and practitioners to implement approaches unconstrained by discipline and sectoral boundaries, geopolitical polarities, or technical problematization. We consider a stronger focus on inclusive creation of knowledge and the interaction of this knowledge with societal values and rules is likely to result in conservation science and practice that meets the challenges of a postnormal world.

Changes in distribution of waterbirds following prolonged drought reflect habitat availability in coastal and inland regions.

Provision of suitable habitat for waterbirds is a major challenge for environmental managers in arid and semiarid regions with high spatial and temporal variability in rainfall. It is understood in broad terms that to survive waterbirds must move according to phases of wet-dry cycles, with coastal habitats providing drought refugia and inland wetlands used during the wet phase. However, both inland and coastal wetlands are subject to major anthropogenic pressures, and the various species of waterbird may have particular habitat requirements and respond individualistically to spatiotemporal variations in resource distribution. A better understanding of the relationships between occurrence of waterbirds and habitat condition under changing climatic conditions and anthropogenic pressures will help clarify patterns of habitat use and the targeting of investments in conservation. We provide the first predictive models of habitat availability between wet and dry phases for six widely distributed waterbird species at a large spatial scale. We first test the broad hypothesis that waterbirds are largely confined to coastal regions during a dry phase. We then examine the contrasting results among the six species, which support other hypotheses erected on the basis of their ecological characteristics. There were large increases in area of suitable habitat in inland regions in the wet year compared with the dry year for all species, ranging from 4.14% for Australian White Ibis to 31.73% for Eurasian Coot. With over half of the suitable habitat for three of the six species was located in coastal zones during drought, our study highlights the need to identify and conserve coastal drought refuges. Monitoring of changes in extent and condition of wetlands, combined with distribution modeling of waterbirds, will help support improvements in the conservation and management of waterbirds into the future.

The Crotonia fauna of New Zealand revisited (Acari: Oribatida): taxonomy, phylogeny, ecological distribution and biogeography.

New Zealand contains 13 of the 69 species of Crotonia described globally and is the only place where all three genera of the Crotoniinae-Crotonia, Austronothrus and Holonothrus-have been recorded. Due to the pioneering work of Hammer (1966) and Luxton (1982) it also has the highest number of distribution records of Crotonia spp. anywhere. In the present study I build upon previous work to re-examine the Crotonia fauna of New Zealand in the light of recent taxonomic and biogeographical research. A new species is described, C. ramsayi sp. nov., a member of the Unguifera species group, and supplementary descriptions are provided for C. brachyrostrum (Hammer 1966), C. caudalis (Hammer, 1966), C. cophinaria (Michael, 1908), and C. unguifera (Michael 1908), as well as a key to species. Crotonia spp. from New Zealand occur predominantly in localities with relatively low mean annual temperature and high water balance, reflecting a requirement for cool, moist conditions. In New Zealand Crotonia spp. occur in an extremely wide variety of vegetation communities compared with other regions in its range (Australia, Africa and South America), and this is indicative that water balance requirements are met, regardless of vegetation type. Some elements of the New Zealand Crotonia fauna, notably the Cophinaria species group, are common to Australia, Africa and South America, indicating a shared evolutionary history pre-dating the separation of Africa from Gondwana 110 mya. The high proportion of species that occur west of the Alpine Fault is consistent with a relictual distribution of Gondwanan elements on the Australian Plate. However, it is unclear whether uplift of the Southern Alps formed a barrier to dispersal. A high representation of the morphologically closely-related Obtecta, Flagellata and Unguifera groups, shared only with South America (and, for Unguifera, with Oceania) represents a dramatically different faunal composition compared with other former Gondwanan landmasses and is consistent with submergence of most of New Zealand during the Oligocene (ca. 25 mya). All of these characteristics indicate a distinctive evolutionary pathway for the Crotonia fauna since New Zealand separated from the rest of Gondwana 80 mya.

Metabarcoding of benthic eukaryote communities predicts the ecological condition of estuaries.

DNA-derived measurements of biological composition have the potential to produce data covering all of life, and provide a tantalizing proposition for researchers and managers. We used metabarcoding to compare benthic eukaryote composition from five estuaries of varying condition. In contrast to traditional studies, we found biotic richness was greatest in the most disturbed estuary, with this being due to the large volume of extraneous material (i.e. run-off from aquaculture, agriculture and other catchment activities) being deposited in the system. In addition, we found strong correlations between composition and a number of environmental variables, including nutrients, pH and turbidity. A wide range of taxa responded to these environmental gradients, providing new insights into their sensitivities to natural and anthropogenic stressors. Metabarcoding has the capacity to bolster current monitoring techniques, enabling the decisions regarding ecological condition to be based on a more holistic view of biodiversity.

Ecological mechanisms underpinning climate adaptation services.

Ecosystem services are typically valued for their immediate material or cultural benefits to human wellbeing, supported by regulating and supporting services. Under climate change, with more frequent stresses and novel shocks, 'climate adaptation services', are defined as the benefits to people from increased social ability to respond to change, provided by the capability of ecosystems to moderate and adapt to climate change and variability. They broaden the ecosystem services framework to assist decision makers in planning for an uncertain future with new choices and options. We present a generic framework for operationalising the adaptation services concept. Four steps guide the identification of intrinsic ecological mechanisms that facilitate the maintenance and emergence of ecosystem services during periods of change, and so materialise as adaptation services. We applied this framework for four contrasted Australian ecosystems. Comparative analyses enabled by the operational framework suggest that adaptation services that emerge during trajectories of ecological change are supported by common mechanisms: vegetation structural diversity, the role of keystone species or functional groups, response diversity and landscape connectivity, which underpin the persistence of function and the reassembly of ecological communities under severe climate change and variability. Such understanding should guide ecosystem management towards adaptation planning.

Beyond Moa's Ark and Wallace's Line: extralimital distribution of new species of Austronothrus (Acari, Oribatida, Crotoniidae) and the endemicity of the New Zealand oribatid mite fauna.

The genus Austronothrus was previously known from three species recorded only from New Zealand. Austronothrus kinabalu sp. nov. is described from Sabah, Borneo and A. rostralis sp. nov. from Norfolk Island, south-west Pacific. A key to Austronothrus is included. These new species extend the distribution of Austronothrus beyond New Zealand and confirms that the subfamily Crotoniinae is not confined to former Gondwanan landmasses. The distribution pattern of Austronothrus spp., combining Oriental and Gondwanan localities, is indicative of a curved, linear track; consistent with the accretion of island arcs and volcanic terranes around the plate margins of the Pacific Ocean, with older taxa persisting on younger island though localised dispersal within island arc metapopulations. Phylogenetic analysis and an area cladogram are consistent with a broad ancestral distribution of Austronothrus in the Oriental region and on Gondwanan terranes, with subsequent divergence and distribution southward from the Sunda region to New Zealand. This pattern is more complex than might be expected if the New Zealand oribatid fauna was derived from dispersal following re-emergence of land after inundation during the Oligocene (25 mya), as well as if the fauna emanated from endemic, relictual taxa following separation of New Zealand from Gondwana during the Cretaceous (80 mya).

Application of thresholds of potential concern and limits of acceptable change in the condition assessment of a significant wetland.

We propose a framework in which thresholds of potential concern (TPCs) and limits of acceptable change (LACs) are used in concert in the assessment of wetland condition and vulnerability and apply the framework in a case study. The lower Murrumbidgee River floodplain (the 'Lowbidgee') is one of the most ecologically important wetlands in Australia and the focus of intense management intervention by State and Federal government agencies. We used a targeted management stakeholder workshop to identify key values that contribute to the ecological significance of the Lowbidgee floodplain, and identified LACs that, if crossed, would signify the loss of significance. We then used conceptual models linking the condition of these values (wetland vegetation communities, waterbirds, fish species and the endangered southern bell frog) to measurable threat indicators, for which we defined a management goal and a TPC. We applied this framework to data collected across 70 wetland storages', or eco-hydrological units, at the peak of a prolonged drought (2008) and following extensive re-flooding (2010). At the suggestion of water and wetland mangers, we neither aggregated nor integrated indices but reported separately in a series of chloropleth maps. The resulting assessment clearly identified the effect of rewetting in restoring indicators within TPC in most cases, for most storages. The scale of assessment was useful in informing the targeted and timely management intervention and provided a context for retaining and utilising monitoring information in an adaptive management context.

Impacts of inundation and drought on eukaryote biodiversity in semi-arid floodplain soils.

Floodplain ecosystems are characterized by alternating wet and dry phases and periodic inundation defines their ecological character. Climate change, river regulation and the construction of levees have substantially altered natural flooding and drying regimes worldwide with uncertain effects on key biotic groups. In southern Australia, we hypothesized that soil eukaryotic communities in climate change affected areas of a semi-arid floodplain would transition towards comprising mainly dry-soil specialist species with increasing drought severity. Here, we used 18S rRNA amplicon pyrosequencing to measure the eukaryote community composition in soils that had been depleted of water to varying degrees to confirm that reproducible transitional changes occur in eukaryotic biodiversity on this floodplain. Interflood community structures (3 years post-flood) were dominated by persistent rather than either aquatic or dry-specialist organisms. Only 2% of taxa were unique to dry locations by 8 years post-flood, and 10% were restricted to wet locations (inundated a year to 2 weeks post-flood). Almost half (48%) of the total soil biota were detected in both these environments. The discovery of a large suite of organisms able to survive nearly a decade of drought, and up to a year submerged supports the concept of inherent resilience of Australian semi-arid floodplain soil communities under increasing pressure from climatic induced changes in water availability.

Provisioning of bioavailable carbon between the wet and dry phases in a semi-arid floodplain.

Ecosystem functioning on arid and semi-arid floodplains may be described by two alternate traditional paradigms. The pulse-reserve model suggests that rainfall is the main driver of plant growth and subsequent carbon and energy reserve formation in the soil of arid and semi-arid regions. The flood pulse concept suggests that periodic flooding facilitates the two-way transfer of materials between a river and its adjacent floodplain, but focuses mainly on the period when the floodplain is inundated. We compared the effects of both rainfall and flooding on soil moisture and carbon in a semi-arid floodplain to determine the relative importance of each for soil moisture recharge and the generation of a bioavailable organic carbon reserve that can potentially be utilised during the dry phase. Flooding, not rainfall, made a substantial contribution to moisture in the soil profile. Furthermore, the growth of aquatic macrophytes during the wet phase produced at least an order of magnitude more organic material than rainfall-induced pulse-reserve responses during the dry phase, and remained as recognizable soil carbon for years following flood recession. These observations have led us to extend existing paradigms to encompass the reciprocal provisioning of carbon between the wet and dry phases on the floodplain, whereby, in addition to carbon fixed during the dry phase being important for driving biogeochemical transformations upon return of the next wet phase, aquatic macrophyte carbon fixed during the wet phase is recognized as an important source of energy for the dry phase. Reciprocal provisioning presents a conceptual framework on which to formulate questions about the resistance and ecosystem resilience of arid and semi-arid floodplains in the face of threats like climate change and alterations to flood regimes.

Species-groups and biogeography of the oribatid mite family Malaconothridae (Oribatida: Malaconothroidea), with new species from the south-western Pacific region.

Seven new species of Malaconothridae from Papua New Guinea are described: Tyrphonothrus papuensis sp. nov., Malaconothrus dispela sp. nov., M gogolensis sp. nov., M laensis sp. nov., M liklik sp. nov., M murmurensis sp. nov. and M. weigmanni sp. nov.; one from New Caledonia: Tyrphonothrus kanaka sp. nov. and three new species from Australia: Tyrphonothrus seniczaki sp. nov. from Victoria, T kimberleyi sp. nov. and Malaconothrus tidbinbilla sp. nov. from the Australian Capital Territory. These, and previously-described malaconothrids from Australia, are allocated to a series of species groups based on shared characters (Tyrphonothrus: Maior, Sacculus and Crassisetosus; Malaconothrus: Marginatus, Monodactylus, Crispus, Plumosus and Opisthoseta). The species groups were assessed against (a) the biogeographical distribution of their component species and (b) the phylogenetic relatedness of those species. The majority of species groups have a cosmopolitan or semi-cosmopolitan distribution, with the Crassisetosus and Opisthoseta groups distributed on former Gondwanan continents. These findings are consistent with the conclusion of Hammer and Wallwork (1979) that Malaconothridae evolved as part of the Pangaean fauna and that the Opisthoseta group evolved after Gondwana had separated from Laurasia.

A phylogenetic analysis and taxonomic revision of the oribatid mite family Malaconothridae (Acari: Oribatida), with new species of Tyrphonothrus and Malaconothrus from Australia.

Hitherto, the Malaconothridae contained Malaconothrus Berlese, 1904 and Trimalaconothrus Berlese, 1916, defined by the possession of one pre-tarsal claw (monodactyly) or by three claws (tridactyly) respectively. However, monodactyly is a convergent apomorphy within the Oribatida and an unreliable character for a classification. Therefore we undertook a phylogenetic analysis of 102 species as the basis for a taxonomic review of the Malaconothridae. We identified two major clades, equivalent to the genera Tyrphonothrus Knülle, 1957 and Malaconothrus. These genera are redefined. Trimalaconothrus becomes the junior subjective synonym of Malaconothrus. Some 42 species of Trimalaconothrus are recombined to Malaconothrus and 15 species to Tyrphonothrus. Homonyms created by the recombinations are rectified. The replacement name M. hammerae nom. nov. is proposed for M. angulatus Hammer, 1958, the junior homonym of M. angulatus (Willmann, 1931) and the replacement name M. luxtoni nom. nov. is proposed for M. scutatus Luxton, 1987, the junior homonym of M. scutatus Mihelcic, 1959. Trimalaconothrus iteratus Subías, 2004 is an unnecessary replacement name and is a junior objective synonym of Malaconothrus longirostrum (Hammer 1966). Malaconothrus praeoccupatus Subías, 2004 is a junior objective synonym of M. machadoi Balogh & Mahunka, 1969. Malaconothrus obsessus (Subías, 2004), an unnecessary replacement name for Trimalaconothrus albulus Hammer 1966 sensu Tseng 1982, becomes an available name for what is in fact a previously-undescribed species of Malaconothrus. We describe four new species of Tyrphonothrus: T. gnammaensis sp. nov. from Western Australia, T. gringai sp. nov. and T. maritimus sp. nov. from New South Wales, and T. taylori sp. nov. from Queensland. We describe six new species of Malaconothrus: M. beecroftensis sp. nov., M. darwini sp. nov. M. gundungurra sp. nov. and M. knuellei sp. nov. from New South Wales, M. jowettae sp. nov. from Norfolk Island, and M. talaitae sp. nov. from Victoria.