Winter bird communities in pine woodland vs. broadleaf forest on Abaco

We assessed the relative abundance of winter resident birds (species that breed in North America but spend the winter in The Bahamas) through 115 point counts conducted during December and January 2007–2012 on Abaco, The Bahamas. We also analyzed structure and composition of the woody vegetation in Abaco’s two widespread terrestrial habitats: Pineland, an open woodland of Pinus caribaea var. bahamensis (Bahamas Pine) that covers most of the island; and Coppice, a broadleaf, relatively diverse forest that covers <10% of Abaco. Winter resident birds were more abundant in Pineland (8.61 individuals/point) than in Coppice (2.28 individuals/point). Setophaga palmarum (Palm Warbler) and S. coronata (Yellow-rumped Warbler) dominated the winter bird communities in Pineland (44.6% and 37.4% of all detected individuals, respectively), with the next three most common species (S. discolor [Prairie Warbler], Dumetella carolinensis [Gray Catbird], and Geothlypis trichas [Common Yellowthroat]) ranging from 6.5 to 2.0%. The winter species composition in Coppice was more even than in Pineland, featuring S. ruticilla [American Redstart] (39.8%), Prairie Warbler (16.2%), Gray Catbird (13.1%), and the next five most common species (S. americana [Northern Parula], Seiurus aurocapillus [Ovenbird], S. caerulescens [Black-throated Blue Warbler], Mnio- tilta varia [Black-and-white Warbler], and S. citrina [Hooded Warbler]) ranging from 7.3 to 3.1%. In Pineland, bird community composition varied with overstory cover and height, understory cover and type, and ground cover. In contrast, patterns of bird community composition in Coppice were not associated strongly with variation in habitat structure or forest composition. This may reflect that Coppice, experiencing frequent hurricane disturbance, has considerable small-scale heterogeneity in the availability of food for winter resident birds. Comparing our data with those from previous surveys of winter birds conducted 5–40 years earlier in the northern Bahamas, we see little evidence of major changes in this bird community

The Lizards of Rarotonga and Mangaia, Cook Island Group, Oceania

Eight species of lizards are reported from the islands of Rarotonga and Mangaia with comments on their distribution, ecology, reproduction, and variation. Particular attention is given to systematic problems in the genus Cryptoblepharus and pattern polymorphism in Emoia cyanura. Emoia trossula, recently described from Fiji, is reported for the first time in the Cook Islands. Historic and zoogeographic evidence suggests that most species of lizards arrived on Rarotonga and Mangaia in Polynesian voyaging canoes within the past 1000 years, although Gehyra mutilata and Hemidactylus garnotii may have arrived by incidental boat or air transport in the past several decades

Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: Implications for Pre-Hispanic Animal Trade and the Timing of Turkey Domestication

Late Preclassic (300 BC–AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous. Prior to this discovery, the earliest evidence of M. gallopavo in the Maya area dated to approximately one thousand years later. The El Mirador specimens therefore represent previously unrecorded Preclassic exchange of animals from northern Mesoamerica to the Maya cultural region. As the earliest evidence of M. gallopavo found outside its natural geographic range, the El Mirador turkeys also represent the earliest indirect evidence for Mesoamerican turkey rearing or domestication. The presence of male, female and sub-adult turkeys, and reduced flight morphology further suggests that the El Mirador turkeys were raised in captivity. This supports an argument for the origins of turkey husbandry or at least captive rearing in the Preclassic

Forest Plant and Bird Communities in the Lau Group, Fiji

We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km²), Nayau (18.4 km²), and Aiwa Levu (1.2 km²), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity.All trees > 5 cm diameter were measured and identified in 23 forest plots of 500 m² each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba.Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human disturbance

Suppression of type 1 pilus assembly in uropathogenic Escherichia coli by chemical inhibition of subunit polymerization

OBJECTIVES: To identify and to characterize small-molecule inhibitors that target the subunit polymerization of the type 1 pilus assembly in uropathogenic Escherichia coli (UPEC). METHODS: Using an SDS-PAGE-based assay, in silico pre-filtered small-molecule compounds were screened for specific inhibitory activity against the critical subunit polymerization step of the chaperone-usher pathway during pilus biogenesis. The biological activity of one of the compounds was validated in assays monitoring UPEC type 1 pilus biogenesis, type 1 pilus-dependent biofilm formation and adherence to human bladder epithelial cells. The time dependence of the in vivo inhibitory activity and the overall effect of the compound on UPEC growth were determined. RESULTS: N-(4-chloro-phenyl)-2-{5-[4-(pyrrolidine-1-sulfonyl)-phenyl]-[1,3,4]oxadiazol-2-yl sulfanyl}-acetamide (AL1) inhibited in vitro pilus subunit polymerization. In bacterial cultures, AL1 disrupted UPEC type 1 pilus biogenesis and pilus-dependent biofilm formation, and resulted in the reduction of bacterial adherence to human bladder epithelial cells, without affecting bacterial cell growth. Bacterial exposure to the inhibitor led to an almost instantaneous loss of type 1 pili. CONCLUSIONS: We have identified and characterized a small molecule that interferes with the assembly of type 1 pili. The molecule targets the polymerization step during the subunit incorporation cycle of the chaperone-usher pathway. Our discovery provides new insight into the design and development of novel anti-virulence therapies targeting key virulence factors of bacterial pathogens

Crop Updates 2006 - Weeds

This session covers thirty seven papers from different authors: 1. ACKNOWLEDGEMENTS, Alexandra Douglas, CONVENOR – WEEDS DEPARTMENT OF AGRICULTURE SPRAY TECHNOLOGY 2. Meeting the variable application goals with new application technology, Thomas M. Wolf, Agriculture and Agri-Food Canada, Saskatoon Research Centre 3. Spray nozzles for grass weed control, Harm van Rees, BCG (Birchip Cropping Group) 4. Boom sprayer setups – achieving coarse droplets with different operating parameters, Bill Gordon, Bill Gordon Consulting 5. Complying with product label requirements, Bill Gordon, Bill Gordon Consulting 6. IWM a proven performer over 5 years in 33 focus paddocks, Peter Newman and Glenn Adam, Department of Agriculture 7. Crop topping of wild radish in lupins and barley, how long is a piece of string? Peter Newman and Glenn Adam, Department of Agriculture 8. Determining the right timing to maximise seed set control of wild radish, Aik Cheam and Siew Lee, Department of Agriculture 9. Why weed wiping varies in success rates in broadacre crops? Aik Cheam1, Katherine Hollaway2, Siew Lee1, Brad Rayner1 and John Peirce1,1Department of Agriculture, 2Department of Primary Industries, Victoria 10. Are WA growers successfully managing herbicide resistant annual ryegrass? Rick Llewellynabc, Frank D’Emdena, Mechelle Owenb and Stephen Powlesb aCRC Australian Weed Management, School of Agricultural and Resource Economics, University of Western Australia; bWA Herbicide Resistance Initiative, University of Western Australia. cCurrent address: CSIRO Sustainable Ecosystems 11. Do herbicide resistant wild radish populations look different? Michael Walsh, Western Australian Herbicide Resistance Initiative, University of Western Australia 12. Can glyphosate and paraquat annual ryegrass reduce crop topping efficacy? Emma Glasfurd, Michael Walsh and Kathryn Steadman, Western Australian Herbicide Resistance Initiative, University of Western Australia 13. Tetraploid ryegrass for WA. Productive pasture phase AND defeating herbicide resistant ryegrass, Stephen Powlesa, David Ferrisab and Bevan Addisonc, aWA Herbicide Resistance Initiative, University of Western Australia; bDepartment of Agriculture, and cElders Limited 14. Long-term management impact on seedbank of wild radish with multiple resistance to diflufenican and triazines, Aik Cheam, Siew Lee, Dave Nicholson and Ruben Vargas, Department of Agriculture 15. East-west crop row orientation improves wheat and barley yields, Dr Shahab Pathan, Dr Abul Hashem, Nerys Wilkins and Catherine Borger3, Department of Agriculture, 3WAHRI, The University ofWestern Australia 16. Competitiveness of different lupin cultivars with wild radish, Dr Shahab Pathan, Dr Bob French and Dr Abul Hashem, Department of Agriculture 17. Managing herbicide resistant weeds through farming systems, Kari-Lee Falconer, Martin Harries and Chris Matthews, Department of Agriculture 18. Lupins tolerate in-row herbicides well, Peter Newman and Martin Harries, Department of Agriculture 19. Summer weeds can reduce wheat grain yield and protein, Dr Abul Hashem1, Dr Shahab Pathan1 and Vikki Osten3, 1Department Agriculture, 3Senior Agronomist, CRC for Australian Weed Management, Queensland Department of Primary Industries and Fisheries 20. Diuron post-emergent in lupins, the full story, Peter Newman and Glenn Adam, Department of Agriculture 21. Double incorporation of trifluralin, Peter Newman and Glenn Adam, Department of Agriculture 22. Herbicide tolerance of narrow leafed and yellow lupins, Harmohinder Dhammu, David Nicholson, Department of Agriculture 23. MIG narrow leaf lupin herbicide tolerance trial, Richard Quinlan, Planfarm Pty Ltd, Trials Coordinator MIG; Debbie Allen, Research Agronomist – MIG 24. Herbicide tolerance of new albus lupins, Harmohinder Dhammu, David Nicholson, Department of Agriculture 25. Field pea x herbicide tolerance, Mark Seymour and Harmohinder Dhammu, Research Officers, and Pam Burgess, Department of Agriculture 26. Faba bean variety x herbicide tolerance, Mark Seymour and Harmohinder Dhammu, Research Officers, and Pam Burgess, Department of Agriculture 27. Herbicide tolerance of new Kabili chickpeas, Harmohinder Dhammu, Owen Coppen and Chris Roberts, Department of Agriculture 28. Timing of phenoxys application in EAG Eagle Rock, Harmohinder Dhammu, David Nicholson, Department of Agriculture 29. Herbicide tolerance of new wheat varieties, Harmohinder Dhammu, David Nicholson, Department of Agriculture 30. Lathyrus sativus x herbicide tolerance, Mark Seymour, Department of Agriculture 31. Tolerance of annual pasture species to herbicides and mixtures containing diuron, Christiaan Valentine and David Ferris, Department of Agriculture 32. The impact of herbicides on pasture legume species – a summary of scientific trial results across 8 years, Christiaan Valentine and David Ferris, Department of Agriculture 33. The impact of spraytopping on pasture legume seed set, Christiaan Valentine and David Ferris, Department of Agriculture 34. Ascochyta interaction with Broadstrike in chickpeas, H.S. Dhammu1, A.K. Basandrai2,3, W.J. MacLeod1, 3 and C. Roberts1, 1Department of Agriculture, 2CSKHPAU, Dhaulakuan, Sirmour (HP), India and 3CLIMA 35. Best management practices for atrazine in broadacre crops, John Moore, Department of Agriculture, Neil Rothnie, Chemistry Centre of WA, Russell Speed, Department of Agriculture, John Simons, Department of Agriculture, and Ted Spadek, Chemistry Centre of WA 36. Biology and management of red dodder (Cuscuta planiflolia) – a new threat to the grains industry, Abul Hashem, Daya Patabendige and Chris Roberts, Department Agriculture 37. Help the wizard stop the green invaders! Michael Renton, Sally Peltzer and Art Diggle, Department of Agricultur

Effects of global change during the 21st century on the nitrogen cycle

The global nitrogen (N) cycle at the beginning of the 21st century has been shown to be strongly influenced by the inputs of reactive nitrogen (Nr) from human activities, including combustion-related NOx, industrial and agricultural N fixation, estimated to be 220 Tg N yr−1 in 2010, which is approximately equal to the sum of biological N fixation in unmanaged terrestrial and marine ecosystems. According to current projections, changes in climate and land use during the 21st century will increase both biological and anthropogenic fixation, bringing the total to approximately 600 Tg N yr−1 by around 2100. The fraction contributed directly by human activities is unlikely to increase substantially if increases in nitrogen use efficiency in agriculture are achieved and control measures on combustion-related emissions implemented. Some N-cycling processes emerge as particularly sensitive to climate change. One of the largest responses to climate in the processing of Nr is the emission to the atmosphere of NH3, which is estimated to increase from 65 Tg N yr−1 in 2008 to 93 Tg N yr−1 in 2100 assuming a change in global surface temperature of 5 °C in the absence of increased anthropogenic activity. With changes in emissions in response to increased demand for animal products the combined effect would be to increase NH3 emissions to 135 Tg N yr−1. Another major change is the effect of climate changes on aerosol composition and specifically the increased sublimation of NH4NO3 close to the ground to form HNO3 and NH3 in a warmer climate, which deposit more rapidly to terrestrial surfaces than aerosols. Inorganic aerosols over the polluted regions especially in Europe and North America were dominated by (NH4)2SO4 in the 1970s to 1980s, and large reductions in emissions of SO2 have removed most of the SO42− from the atmosphere in these regions. Inorganic aerosols from anthropogenic emissions are now dominated by NH4NO3, a volatile aerosol which contributes substantially to PM10 and human health effects globally as well as eutrophication and climate effects. The volatility of NH4NO3 and rapid dry deposition of the vapour phase dissociation products, HNO3 and NH3, is estimated to be reducing the transport distances, deposition footprints and inter-country exchange of Nr in these regions. There have been important policy initiatives on components of the global N cycle. These have been regional or country-based and have delivered substantial reductions of inputs of Nr to sensitive soils, waters and the atmosphere. To date there have been no attempts to develop a global strategy to regulate human inputs to the nitrogen cycle. However, considering the magnitude of global Nr use, potential future increases, and the very large leakage of Nr in many forms to soils, waters and the atmosphere, international action is required. Current legislation will not deliver the scale of reductions globally for recovery from the effects of Nr deposition on sensitive ecosystems, or a decline in N2O emissions to the global atmosphere. Such changes would require substantial improvements in nitrogen use efficiency across the global economy combined with optimization of transport and food consumption patterns. This would allow reductions in Nr use, inputs to the atmosphere and deposition to sensitive ecosystems. Such changes would offer substantial economic and environmental co-benefits which could help motivate the necessary actions