Agricultural extension policy in Australia: public funding and market failure

Trends in public expenditure on agricultural extension are examined for Agriculture Departments in four States. There is little evidence that the share of public resources going to extension has declined. However, new demands have meant that the nature of extension has changed. A strategic approach to examining issues, such as land degradation, for the source of market failure may better guide the use of scarce public resources than the traditional focus on the public goods characteristics of research and extension. The case for evaluating broad functions such as research and extension is becoming more questionable as these functions become more diverse.Teaching/Communication/Extension/Profession,

Benchmarking of a 1D Scrape-off layer code SOLF1D with SOLPS and its use in modelling long-legged divertors

A 1D code modelling SOL transport parallel to the magnetic field (SOLF1D) is benchmarked with 2D simulations of MAST-U SOL performed via the SOLPS code for two different collisionalities. Based on this comparison, SOLF1D is then used to model the effects of divertor leg stretching in 1D, in support of the planned Super-X divertor on MAST. The aim is to separate magnetic flux expansion from volumetric power losses due to recycling neutrals by stretching the divertor leg either vertically or radially.Comment: 31 pages, 17 figures. This is an author-created, un-copyedited version of an article accepted for publication in Plasma Physics and Controlled Fusion. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

A revision of the grasshopper genus Orthochtha and its allies (Orthoptera: Acrididae: Acridinae)

This revision concerns the genera Orthochtha, Euprepoptera, Lobopoma, Pamacris and Xerophlaeoba, which are diagnosed and redescribed, plus three others erected here: Shabacris for Lobopoma robusta, Nimbacris for Lobopoma longicornis and Xenocymochtha for a new species, barkeri, here described. As now recognized, Orthochtha comprises 25 species and 11 subspecies of which 12 species and five subspecies respectively are described here as new, while the identity of another species, O. angustata, remains uncertain. Of the other genera, two species are now recognized within Euprepoptera, one of which is new, three within Lobopoma (two new) and two within Pamacris, with carterocera transferred from Lobopoma. In all, 36 species and 11 subspecies are diagnosed, illustrated, keyed and their distributions mapped. Six new synonymies are established and four specific names recalled but given new status as subspecies; two other species are reduced to the rank of subspecies. Six lectotypes and one neotype are designated. The affinities of the taxa are discussed on the basis of classical taxonomic criteria and also by numerical analysis. Their biogeographies are assessed, notably in terms of the postulated environmental influences on their evolution. A synopsis of the available information on the biology, ecology and economic importance is given for each species

Quantifying resistance and resilience to local extinction for conservation prioritization

This is the final version. Available on open access from Ecological Society of America via the DOI in this recordSpecies-focused conservation planning is often based on reducing local extinction risk at key sites. However, with increasing levels of habitat fragmentation and pressures from climate change and overexploitation, surrounding landscapes also influence the persistence of species populations, and their effects are increasingly incorporated in conservation planning and management for both species and communities. Here, we present a framework based on metapopulation dynamics in fragmented landscapes, for quantifying the survival (resistance) and reestablishment of species populations following localized extinction events (resilience). We explore the application of this framework to guide the conservation of a group of threatened bird species endemic to papyrus (Cyperus papyrus) swamps in East and Central Africa. Using occupancy data for five species collected over two years from a network of wetlands in Uganda, we determine the local and landscape factors that influence local extinction and colonization, and map expected rates of population turnover across the network to draw inferences about the locations which contribute most to regional resistance and resilience for all species combined. Slight variation in the factors driving extinction and colonization between individual papyrus birds led to species-specific differences in the spatial patterns of site-level resistance and resilience. However, despite this, locations with the highest resistance and/or resilience overlapped for most species and reveal where resources could be invested for multi-species persistence. This novel simplified framework can aid decision making associated with conservation planning and prioritization for multiple species residing in overlapping, fragmented habitats; helping to identify key sites that warrant urgent conservation protection, with consideration of the need to adapt and respond to future change. This article is protected by copyright. All rights reserved.Natural Environment Research Council (NERC)The Explorers ClubBritish Ornithologists’ UnionRoyal Geographic SocietyJohn Muir TrustGilchrist Educational Trus

A fruit diet rather than invertebrate diet maintains a robust innate immunity in an omnivorous tropical songbird

Experiments were funded by the Royal Netherlands Academy of Arts and Sciences (KNAW) Academy Ecology Fund to C.J.N—(KENMERK J1618/ECO/G437). C.J.N. was supported by a studentship funded by the Leventis Conservation Foundation through the University of St. Andrews UK and an Ubbo Emmius grant of the University of Groningen, The Netherlands. B.I.T. was supported by the Netherlands Organisation for Scientific Research (NWO‐Vidi 864.10.012).1. Diet alteration may lead to nutrient limitations even in the absence of food limitation, and this may affect physiological functions, including immunity. Nutrient limitations may also affect the maintenance of body mass and key life history events that may affect immune function. Yet, variation in immune function is largely attributed to energetic trade-offs rather than specific nutrient constraints. 2. To test the effect of diet on life history traits, we tested how diet composition affects innate immune function, body mass and moult separately and in combination with each other, and then used path analyses to generate hypotheses about the mechanistic connections between immunity and body mass under different diet composition. 3. We performed a balanced parallel and crossover design experiment with omnivorous common bulbuls Pycnonotus barbatus in out-door aviaries in Nigeria. We fed 40 wild-caught bulbuls ad libitum on fruits or invertebrates for 24 weeks, switching half of each group between treatments after 12 weeks. We assessed innate immune indices (haptoglobin, nitric oxide and ovotransferrin concentrations, and haemagglutination and haemolysis titres), body mass and primary moult, fortnightly. We simplified immune indices into three principal components (PCs), but we explored mechanistic connections between diet, body mass and each immune index separately. 4. Fruit fed bulbuls had higher body mass, earlier moult and showed higher values for two of the three immune PCs compared to invertebrate fed bulbuls. These effects were reversed when we switched bulbuls between treatments after 12 weeks. Exploring the correlations between immune function, body mass and moult, showed that an increase in immune function was associated with a decrease in body mass and delayed moult in invertebrate fed bulbuls, while fruit fed bulbuls maintained body mass despite variation in immune function. Path analyses indicated that diet composition was most likely to affect body mass and immune indices directly and independently from each other. Only haptoglobin concentration was indirectly linked to diet composition via body mass. 5. We demonstrated a causal effect of diet composition on innate immune function, body mass and moult: bulbuls were in better condition when fed on fruits than invertebrates, confirming that innate immunity is nutrient specific. Our results are unique because they show a reversible effect of diet composition on wild adult birds whose immune systems are presumably fully developed and adapted to wild conditions – demonstrating a short-term consequence of diet alteration on life history traits.Publisher PDFPeer reviewe

Evaluation of cultural control and resistance‐breeding strategies for suppression of whitefly infestation of cassava at the landscape scale: a simulation modeling approach

Background: The whitefly Bemisia tabaci is an important vector of virus diseases, impacting cassava production in East Africa. To date, breeding efforts in this region have focused on disease resistance. Here we use a spatially‐explicit simulation model to explore how breeding strategies for whitefly resistance will influence the population dynamics of whitefly in the context of regional variation in cassava crop management practices. Results: Simulations indicated that regions with a short cropping cycle and two cropping seasons per year were associated with high whitefly abundance. Nymph mortality and antixenosis resistance mechanisms were more effective than mechanisms that lead to longer whitefly development times. When spatial variation was introduced in heterogeneous landscapes, however, negative consequences of the antixenosis effect were observed in fields containing whitefly susceptible varieties, unless the proportion of whitefly resistant variety in the landscape was low (~10%) or the amount of matrix in the landscape was high (~75%). Conclusion: We show the importance of considering cropping regime and landscape management context when developing and deploying whitefly‐resistant cassava varieties. Recommendations differ significantly between regions. There may also be unintended negative consequences of higher whitefly densities for whitefly susceptible varieties if uptake of the new variety in a landscape is high, depending on the mechanism of resistance and the landscape context. Furthermore, we show that in some cases, such as where there is substantial fallow combined with a short single‐season crop, the management characteristics of the existing cropping regime alone may be effective at controlling whitefly populations

Quaternary land bridges have not been universal conduits of gene flow

Quaternary climate oscillations are a well‐known driver of animal diversification, but their effects are most well studied in areas where glaciations lead to habitat fragmentation. In large areas of the planet, however, glaciations have had the opposite effect, but here their impacts are much less well understood. This is especially true in Southeast Asia, where cyclical changes in land distribution have generated enormous land expansions during glacial periods. In this study, we selected a panel of five songbird species complexes covering a range of ecological specificities to investigate the effects Quaternary land bridges have had on the connectivity of Southeast Asian forest biota. Specifically, we combined morphological and bioacoustic analysis with an arsenal of population genomic and modelling approaches applied to thousands of genome‐wide DNA markers across a total of more than 100 individuals. Our analyses show that species dependent on forest understorey exhibit deep differentiation between Borneo and western Sundaland, with no evidence of gene flow during the land bridges accompanying the last 1–2 ice ages. In contrast, dispersive canopy species and habitat generalists have experienced more recent gene flow. Our results argue that there remains much cryptic species‐level diversity to be discovered in Southeast Asia even in well‐known animal groups such as birds, especially in nondispersive forest understorey inhabitants. We also demonstrate that Quaternary land bridges have not been equally suitable conduits of gene flow for all species complexes and that life history is a major factor in predicting relative population divergence time across Quaternary climate fluctuations

A sandpile model with tokamak-like enhanced confinement phenomenology

Confinement phenomenology characteristic of magnetically confined plasmas emerges naturally from a simple sandpile algorithm when the parameter controlling redistribution scalelength is varied. Close analogues are found for enhanced confinement, edge pedestals, and edge localised modes (ELMs), and for the qualitative correlations between them. These results suggest that tokamak observations of avalanching transport are deeply linked to the existence of enhanced confinement and ELMs.Comment: Manuscript is revtex (latex) 1 file, 7 postscript figures Revised version is final version accepted for publication in PRL Revisions are mino

Comparison of acoustic and traditional point count methods to assess bird diversity and composition in the Aberdare National Park, Kenya

Afromontane forests, like those in the Aberdare National Park (ANP) in Kenya, sustain unique avifaunal assemblages. There is a growing need for biodiversity inventories for Afromontane forests, especially through the utilisation of unskilled observers. Acoustic surveys are a potential aid to this, but more comparisons of this technique with that of traditional point counts are needed. We conducted a systematic survey of the ANP avifauna, assessing whether acoustic and traditional surveys resulted in different species richness scores, and whether this varied with habitat and species characteristics. We also investigated the role of habitat and elevation in driving variation in species richness. The ANP provides habitat types including scrub, moorland, montane, hagenia and bamboo forests. Overall, the surveys yielded 101 identified species. The acoustic method resulted in higher species richness scores compared to the traditional method across all habitats, and the relative performance of the two methods did not vary with habitat type or visibility. The methods detected different species, suggesting that they should be used together to maximise the range of species recorded. We found that habitat type was the primary driver of variation in species richness, with scrub and montane forest having higher species richness scores than other habitats