Do bird communities differ with post-fire age in Banksia woodlands of south-western Australia?

Prescribed fire is a widespread management practice in fire-prone ecosystems that can have significant effects on fauna. To inform the development of appropriate prescribed burning regimes, we explored bird responses to time since fire in threatened Banksia woodlands in south-western Australia. We used area searches to estimate bird densities on 20 plots ranging from 1 to 26 years post fire. Fire had no significant effect on the overall bird community or any foraging guilds and there was no clear post-fire succession. Of the 26 frequently occurring species analysed, only two showed responses to fire, with yellow-rumped thornbills more abundant in early and late post-fire sites and scarlet robins more abundant in either early, or early and late post-fire habitats. Our study suggested that bird communities in Banksia woodlands are quite adaptable to a range of prescribed burning regimes. However, owing to late-successional reptiles, Carnaby\u27s black cockatoo and mammals in Banksia woodlands, we recommend prescribed burning regimes that reduce early and increase late successional habitat. Phytophthora dieback, urbanisation and associated habitat fragmentation and a drying climate may have important synergistic effects and the role of these in structuring bird communities needs to be further considered in developing appropriate fire regimes

Landscape ideology in the Greater Golden Horseshoe Greenbelt Plan: Negotiating material landscapes and abstract ideals in the city\u27s countryside

We analyze the role of landscape ideology in the recent Ontario Greater Golden Horseshoe (GGH) Greenbelt Plan. Focusing on the “Protected Countryside,” the major land-use designation in the Plan that structures the Greenbelt framework, we explore tensions between abstract ideals of countryside used by policy makers to elicit support for the Plan and people\u27s lived experience of material landscapes of the peri-urban fringe. Approaching “countryside” from the combined perspectives of landscape studies and political ecology, we show how the abstract ideals used to build support for the protection of countryside in the high-level political arena are in tension with existing material landscapes as people experience them. When implementing the Greenbelt Plan, the abstract ideals have to be applied at the landscape level through negotiation with municipalities, property owners, and other interests. In addition to drawing upon more conventionally legitimate explanations for landscape protection based on environmental science and land-use planning principles, the designation of Protected Countryside and the strategies used to implement the Protected Countryside designation at the local level suggest a tentative commitment to recognizing landscape values and collaborative environmental management processes in policy-making. As with any such normative land-use plan, the success of the Greenbelt Plan hinges on the long-term agreement between planning agencies and diverse publics. We demonstrate the usefulness of approaching environmental management challenges at the urban–rural interface by bringing the perspectives of landscape studies and political ecology into implementation processes for land-use management strategies like the Greenbelt. We argue that public participants deserve legitimate collaborative roles in negotiating just and desirable land uses based on their experiences, and provide observations on ways to bring contested goals and tools for achieving them into reflexive negotiations about how landscapes are and should be produced

Negative-index bi-anisotropic photonic metamaterial fabricated by direct laser writing and silver shadow evaporation

We present the blueprint for a novel negative-index metamaterial. This structure is fabricated via three-dimensional two-photon direct laser writing and silver shadow evaporation. The comparison of measured linear optical spectra with theory shows good agreement and reveals a negative real part of the refractive index at around 3.85 micrometer wavelength - despite the fact that the metamaterial structure is bi-anisotropic due to the lack of inversion symmetry along its surface normal.Comment: 8 pages, 3 figure

Dynamical Bonding Driving Mixed Valency in a Metal Boride

Samarium hexaboride is an anomaly, having many exotic and seemingly mutually incompatible properties. It was proposed to be a mixed-valent semiconductor, and later - a topological Kondo insulator, and yet has a Fermi surface despite being an insulator. We propose a new and unified understanding of SmB$_6$ centered on the hitherto unrecognized dynamical bonding effect: the coexistence of two Sm-B bonding modes within SmB$_6$, corresponding to different oxidation states of the Sm. The mixed valency arises in SmB$_6$ from thermal population of these distinct minima enabled by motion of B. Our model simultaneously explains the thermal valence fluctuations, appearance of magnetic Fermi surface, excess entropy at low temperatures, pressure-induced phase transitions, and related features in Raman spectra and their unexpected dependence on temperature and boron isotope

Complexity of childhood sexual abuse: predictors of current post-traumatic stress disorder, mood disorders, substance use, and sexual risk behavior among adult men who have sex with men

Men who have sex with men (MSM) are the group most at risk for HIV and represent the majority of new infections in the United States. Rates of childhood sexual abuse (CSA) among MSM have been estimated as high as 46 %. CSA is associated with increased risk of HIV and greater likelihood of HIV sexual risk behavior. The purpose of this study was to identify the relationships between CSA complexity indicators and mental health, substance use, sexually transmitted infections, and HIV sexual risk among MSM. MSM with CSA histories (n = 162) who were screened for an HIV prevention efficacy trial completed comprehensive psychosocial assessments. Five indicators of complex CSA experiences were created: CSA by family member, CSA with penetration, CSA with physical injury, CSA with intense fear, and first CSA in adolescence. Adjusted regression models were used to identify relationships between CSA complexity and outcomes. Participants reporting CSA by family member were at 2.6 odds of current alcohol use disorder (OR 2.64: CI 1.24–5.63), two times higher odds of substance use disorder (OR 2.1: CI 1.02–2.36), and 2.7 times higher odds of reporting an STI in the past year (OR 2.7: CI 1.04–7.1). CSA with penetration was associated with increased likelihood of current PTSD (OR 3.17: CI 1.56–6.43), recent HIV sexual risk behavior (OR 2.7: CI 1.16–6.36), and a greater number of casual sexual partners (p = 0.02). Both CSA with Physical Injury (OR 4.05: CI 1.9–8.7) and CSA with Intense Fear (OR 5.16: CI 2.5–10.7) were related to increased odds for current PTSD. First CSA in adolescence was related to increased odds of major depressive disorder. These findings suggest that CSA, with one or more complexities, creates patterns of vulnerabilities for MSM, including post-traumatic stress disorder, substance use, and sexual risk taking, and suggests the need for detailed assessment of CSA and the development of integrated HIV prevention programs that address mental health and substance use comorbidities.This study was supported by a Grant from the NIMH (R01 MH095624) PI: O'Cleirigh; Author time (Safren) was supported, in part, by Grant 5K24MH094214. (R01 MH095624 - NIMH; 5K24MH094214)Accepted manuscrip

The fossil record of early tetrapods: worker effort and the end-Permian mass extinction

It is important to understand the quality of the fossil record of early tetrapods (Tetrapoda, minus Lissamphibia and Amniota) because of their key role in the transition of vertebrates from water to land, their dominance of terrestrial faunas for over 100 million years of the late Palaeozoic and earlyMesozoic, and their variable fates during the end−Permian mass extinction. The first description of an early tetrapod dates back to 1824, and since then discoveries have occurred at a rather irregular pace, with peaks and troughs corresponding to some of the vicissitudes of human history through the past two centuries. As expected, the record is dominated by the well−sampled sedimentary basins of Europe and North America, but finds from other continents are increasing rapidly. Comparisons of snapshots of knowledge in 1900, 1950, and 2000 show that discovery of new species has changed the shape of the species−level diversification curve, contrary to earlier studies of family−level taxa. There is, however, little evidence that taxon counts relate to research effort (as counted by numbers of publications), and there are no biasing effects associated with differential study of different time intervals through the late Palaeozoic and Mesozoic. In fact, levels of effort are apparently not related to geological time, with no evidence that workers have spent more time on more recent parts of the record. In particular, the end−Permian mass extinction was investigated to determine whether diversity changes through that interval might reflect worker effort: it turns out that most records of early tetrapod taxa (when corrected for duration of geological series) occur in the Lower Triassic

Advances in restoration ecology: rising to the challenges of the coming decades

Simultaneous environmental changes challenge biodiversity persistence and human wellbeing. The science and practice of restoration ecology, in collaboration with other disciplines, can contribute to overcoming these challenges. This endeavor requires a solid conceptual foundation based in empirical research which confronts, tests and influences theoretical developments. We review conceptual developments in restoration ecology over the last 30 years. We frame our review in the context of changing restoration goals which reflect increased societal awareness of the scale of environmental degradation and the recognition that inter-disciplinary approaches are needed to tackle environmental problems. Restoration ecology now encompasses facilitative interactions and network dynamics, trophic cascades, and above- and below ground linkages. It operates in a non-equilibrium, alternative states framework, at the landscape scale, and in response to changing environmental, economic and social conditions. Progress has been marked by conceptual advances in the fields of trait-environment relationships, community assembly, and understanding the links between biodiversity and ecosystem functioning. Conceptual and practical advances have been enhanced by applying evolving technologies, including treatments to increase seed germination and overcome recruitment bottlenecks, high throughput DNA sequencing to elucidate soil community structure and function, and advances in satellite technology and GPS tracking to monitor habitat use. The synthesis of these technologies with systematic reviews of context dependencies in restoration success, model based analyses and consideration of complex socio-ecological systems will allow generalizations to inform evidence based interventions. Ongoing challenges include setting realistic, socially acceptable goals for restoration under changing environmental conditions, and prioritizing actions in an increasingly space-competitive world. Ethical questions also surround the use of genetically modified material, translocations, taxon substitutions, and de-extinction, in restoration ecology. Addressing these issues, as the Ecological Society of America looks to its next century, will require current and future generations of researchers and practitioners, including economists, engineers, philosophers, landscape architects, social scientists and restoration ecologists, to work together with communities and governments to rise to the environmental challenges of the coming decades