Variation in fire interval sequences has minimal effects on species richness and composition in fire-prone landscapes of south-west Western Australia   总被引：1，自引：0，他引：1  

Roy S. Wittkuhn  Lachie McCaw  Allan J. Wills  Paul Van Heurck 《Forest Ecology and Management》2011,261(6):965-978

Prescribed burning is used in many fire-prone ecosystems for wildfire mitigation and conservation of biodiversity. However, there is limited information about how biota responds to long-term fire management, especially at a whole-of-community level. We studied community responses to different fire interval sequences resulting from planned and unplanned fires in Mediterranean-climate ecosystems in the Warren bioregion of south-west Western Australia (SWA) to determine the resilience of the biota to contrasting fire regimes. Fire history data were used to identify contrasting fire interval sequences in forest and shrubland communities for the period 1972-2004. We surveyed vascular plants, ants, beetles, vertebrates and macrofungi at 30 sites to investigate community-level responses to consecutive short (SS: ≤5 years), consecutive long (LL: ≥10 years), one very long (VL: 30 years), or mixed/moderate (M: 6-9 years) fire interval(s). All sites had a common time-since-fire of ∼4 years at the commencement of sampling which was conducted over two years. Species richness and composition differed between forest and shrubland communities, but the influence of fire interval sequences on taxonomic groups was minimal and difficult to detect. There was weak evidence of compositional differences between SS and LL/VL regimes for plants, ants, beetles and macrofungi but no difference between these regimes and the intermediate disturbance M-regime. These results demonstrate the resilience of the biota in open forests and shrublands of SWA to contrasting fire interval sequences over the past 30 years. We conclude that occasional short (3-5 years) intervals between fires are unlikely to have a persistent effect on community composition, though maintaining a regime of short or long intervals may alter species composition and/or abundance. We suggest that variability in fire intervals is important for long-term conservation of the biota. For the Warren Region, prescribed burning at an intermediate level of disturbance and incorporating variability in interval length is recommended to achieve the dual objectives of wildfire mitigation and biodiversity conservation.  相似文献   

Identifying, managing and monitoring conflicts between forest biodiversity conservation and other human interests in Europe   总被引：3，自引：0，他引：3  

Jari Niemel  Juliette Young  Didier Alard  Miren Askasibar  Klaus Henle  Richard Johnson  Mikko Kurttila  Tor-Bjrn Larsson  Simone Matouch  Peter Nowicki  Rosa Paiva  Luigi Portoghesi  Ren Smulders  Alan Stevenson  Urmas Tartes  Allan Watt 《Forest Policy and Economics》2005,7(6):877-890

In this paper, circumstances where various human activities and interests clash with the conservation of forest biodiversity are examined, with particular focus on the drivers behind the conflicts. After identifying past and current human-related threats potentially leading to conflicts in forests, the paper will focus on conflict management and monitoring, with an emphasis on inclusionary stakeholder networks and a range of approaches towards sustainable land use. Three dimensions of conflicts are examined: substance (‘how things are’), procedure (‘how things are done’), and relationships (‘how people behave’). These relations will relate to three conflict management approaches: (1) technical, which may contribute to reduce or solve the conflict acting on the ‘substance’ dimension, (2) political, which may influence the ‘procedure’ dimension of the conflict establishing principles or rules, and (3) cultural, which may affect the ‘relationship’ dimension of the conflict. Finally, a general model of adaptive conflict management emphasising communication among the parties and a participatory approach that involves monitoring of the conflict resolution outcomes is proposed. The recognition that strong perceptions among stakeholders have the potential to aggravate conflicts is central to the concept of a inclusionary conflict management framework, improved communication between all stakeholders, and better awareness of the context of the conflicts is emphasised.  相似文献   

Loblolly and slash pine height and diameter are related to soil drainage in winter on poorly drained silt loams     

James D. Haywood  Allan E. Tiarks  Eugene Shoulders 《New Forests》1990,4(2):81-96

Soil drainage characteristics in winter and the heights and diameters of 10-year-old loblolly and slash pines (Pinus taeda L. and P. elliottii Engelm. var. elliottii) were measured on three poorly-drained silt loam sites that had been bedded, furrowed, or disked before planting. Quadratic response functions were used to determine the relationship between depth to water table or volume of drained soil in winter and mean tree height or diameter. These quadratic response functions (species × height or diameter: drainage characteristics) showed that diameter and height were significantly related to soil drainage in winter on these silt loams soils. Slash pines grew better than loblolly pines under more poorly drained conditions while loblolly pines grew better under the better drained conditions. On unbedded silt loams, the soil drainage in winter needed to maximize tree height was 42 cm for loblolly and 49 cm for slash pine. Pines planted on beds did not generally grow better than those on flat-disked plots because where bedding would be most benefical the practice did not form enough additional drainage to significantly influence pine development.  相似文献   

Enhancement of SIV infection with soluble receptor molecules   总被引：27，自引：0，他引：27  

J S Allan  J Strauss  D W Buck 《Science (New York, N.Y.)》1990,247(4946):1084-1088

The CD4 receptor on human T cells has been shown to play an integral part in the human immunodeficiency virus type 1 (HIV-1) infection process. Recombinant soluble human CD4 (rCD4) was tested for its ability to inhibit SIVagm, an HIV-like virus that naturally infects African green monkeys, in order to define T cell surface receptors critical for SIVagm infection. The rCD4 was found to enhance SIVagm infection of a human T cell line by as much as 18-fold, whereas HIV-1 infection was blocked by rCD4. Induction of syncytium formation and de novo protein synthesis were observed within the first 24 hours after SIVagm infection, whereas this process took 4 to 6 days in the absence of rCD4. This enhancing effect could be inhibited by monoclonal antibodies directed to rCD4. The enhancing effect could be abrogated with antibodies from naturally infected African green monkeys with inhibitory titers of from 1:2,000 to 1:10,000; these antibodies did not neutralize SIVagm infection in the absence of rCD4. Viral enhancement of SIVagm infection by rCD4 may result from the modulation of the viral membrane through gp120-CD4 binding, thus facilitating secondary events involved in viral fusion and penetration.  相似文献   

Rab1 recruitment of p115 into a cis-SNARE complex: programming budding COPII vesicles for fusion     

Allan BB  Moyer BD  Balch WE 《Science (New York, N.Y.)》2000,289(5478):444-448

The guanosine triphosphatase Rab1 regulates the transport of newly synthesized proteins from the endoplasmic reticulum to the Golgi apparatus through interaction with effector molecules, but the molecular mechanisms by which this occurs are unknown. Here, the tethering factor p115 was shown to be a Rab1 effector that binds directly to activated Rab1. Rab1 recruited p115 to coat protein complex II (COPII) vesicles during budding from the endoplasmic reticulum, where it interacted with a select set of COPII vesicle-associated SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) to form a cis-SNARE complex that promotes targeting to the Golgi apparatus. We propose that Rab1-regulated assembly of functional effector-SNARE complexes defines a conserved molecular mechanism to coordinate recognition between subcellular compartments.  相似文献   

Landcare in Australia: Beyond the expert farmer     

Allan Curtis  Terry De Lacy 《Agriculture and Human Values》1996,13(1):20-31

The landcare program has been embraced by governments, farmer organizations and conservation groups throughout Australia as offering a model for effective community action to assist the move to more sustainable resource use. Over 2,500 landcare-type groups now operate across Australia with 65,000 members including almost 30% of the farming community. This research used surveys of landcare group activity in most Australian states, a study of the regional landcare action plan (RLAP) process in the state of Victoria, and a survey of landholders in north east Victoria to assess landcare program effectiveness, and particularly, the assumptions underlying the program logic. Information provided revealed the vast scale of community participation in landcare and the considerable amount of onground work undertaken by groups and landholders. Analysis of north east landholder surveys indicated landcare participation had a significant impact upon landholder awareness of issues, level of knowledge, and adoption of best bet practices. However, research findings also highlighted a number of concerns about the program logic and implementation, and the authors suggest it is time to adopt a revised landcare program model.  相似文献   

Is there an intrinsic period of the circadian clock? Response     

Czeisler CA  Dijk DJ  Kronauer RE  Brown EN  Duffy JF  Allan JS  Shanahan TL  Rimmer DW  Ronda JM  Mitchell JF  Silva EJ  Emens JS 《Science (New York, N.Y.)》2000,288(5469):1174-1175

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Ocean science. Whither Antarctic sea ice?     

Wolff EW;British Antarctic Survey  High Cross  Madingley Road  Cambridge CB ET  UK. ewwo@bas.ac.uk 《Science (New York, N.Y.)》2003,302(5648):1164

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Epidermal viral immunity induced by CD8alpha+ dendritic cells but not by Langerhans cells     

Allan RS  Smith CM  Belz GT  van Lint AL  Wakim LM  Heath WR  Carbone FR 《Science (New York, N.Y.)》2003,301(5641):1925-1928

The classical paradigm for dendritic cell function derives from the study of Langerhans cells, which predominate within skin epidermis. After an encounter with foreign agents, Langerhans cells are thought to migrate to draining lymph nodes, where they initiate T cell priming. Contrary to this, we show here that infection of murine epidermis by herpes simplex virus did not result in the priming of virus-specific cytotoxic T lymphocytes by Langerhans cells. Rather, the priming response required a distinct CD8alpha+ dendritic cell subset. Thus, the traditional view of Langerhans cells in epidermal immunity needs to be revisited to accommodate a requirement for other dendritic cells in this response.  相似文献   

Solutions to Environmental and Economic Problems (STEEP)     

Oldenstadt DL  Allan RE  Bruehl GW  Dillman DA  Michalson EL  Papendick RI  Rydrych DJ 《Science (New York, N.Y.)》1982,217(4563):904-909

This article describes one model for organizing and mobilizing scientific resources to address the highly complex and costly problem of soil erosion in the Pacific Northwest. With a U.S. Department of Agriculture grant to the agricultural experiment stations in Washington, Oregon, and Idaho, as well as supplementary state and federal funds, STEEP awards intermediate-term (15 year) grants for research in five areas: tillage and plant management, plant design, erosion and runoff predictions, pest management, and socioeconomics of erosion control. Most of the research projects require collaboration across disciplines and, in some instances, across state boundaries. After 6 years of effort the results obtained with STEEP indicate that the model might be applicable to other regions and problems.  相似文献