66 research outputs found

    Temperature Sensitivity of Mineral Soil Carbon Decomposition in Shrub and Graminoid Tundra, West Greenland

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    Background: Shrub expansion is transforming Arctic tundra landscapes, but the impact on the large pool of carbon stored in high-latitude soils is poorly understood. Soil carbon decomposition is a potentially important source of greenhouse gases, which could create a positive feedback to atmospheric temperature. Decomposition is temperature sensitive, but the response to temperature can be altered by environmental variables. We focus on mineral soils, which can comprise a substantial part of the near-surface carbon stock at the landscape scale and have physiochemical characteristics that influence temperature sensitivity. We conducted a soil incubation experiment to measure carbon dioxide (CO2) emissions from tundra soils collected from west Greenland at two depths of mineral soils (0-20 cm and 20-40 cm below the surface organic horizon) incubated at five temperatures (4, 8, 12, 16, 24 °C) and two moisture levels (40 % and 60 % water holding capacity). We used an information theoretic model comparison approach to evaluate temperature, moisture and depth effects, and associated interactions, on carbon losses through respiration and to determine the temperature sensitivity of decomposition in shrub- and graminoid-dominated soils. Results: We measured ecologically important differences in heterotrophic respiration and temperature sensitivity of decomposition between vegetation types. Graminoid soils had 1.8 times higher cumulative respiration and higher temperature sensitivity (expressed as Q-10) in the shallow depths (Q-10graminoid = 2.3, Q-10shrub = 1.8) compared to shrub soils. Higher Q-10 in graminoid soils was also observed for the initial incubation measurements (Q-10graminoid = 2.4, Q-10shrub = 1.9). Cumulative respiration was also higher for shallow soils, increased with moisture level, and had a temperature-depth interaction. Increasing soil moisture had a positive effect on temperature sensitivity in graminoid soils, but not in shrub soils. Conclusion: Mineral soil associated with graminoid-dominated vegetation had greater carbon losses from decomposition and a higher temperature sensitivity than shrub-dominated soils. An extrapolation of our incubation study suggests that organic carbon decomposition in western Greenland soils will likely increase with warming and with an increase in soil moisture content. Our results indicate that landscape level changes in vegetation and soil heterogeneity are important for understanding climate feedbacks between tundra and the atmosphere

    Benefiting All Users: Gender Equality and Inclusion

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    Women’s needs and priorities often differ from those of men, and their ability to access and use climate services is significantly more constrained. To address these disparities, and to ensure access to and benefit from these services, it is critical to use gender-informed approaches

    The Case for Agricultural Climate Services in Africa

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    Ninety percent of the world’s farms are managed by small-scale farmers, feeding millions of people. Unfortunately, those farmers face significant impacts from climate variability and change. These impacts disrupt their ability to meet livelihoods and sustenance needs, and to produce enough food for a growing world. Climate services provide information about these impacts and aim to support agricultural decision-making for improved livelihoods, resilience, and food security

    Making Climate Services Work for Africa's Farmers at Scale

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    The substantial body of knowledge about good practice in climate services suggests that making climate services work for farmers at a national scale requires managing tradeoffs between meeting farmers’ context-specific needs and providing cost-effective services at scale

    Advancing Impact Evaluations of Agricultural Climate Services in Africa

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    The design and implementation of effective climate information services (CIS) requires understanding the extent to which they impact the decisions and lives of those who use them

    Environmental change: prospects for conservation and agriculture in a southwest Australia biodiversity hotspot

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    Accelerating environmental change is perhaps the greatest challenge for natural resource management; successful strategies need to be effective for decades to come. Our objective is to identify opportunities that new environmental conditions may provide for conservation, restoration, and resource use in a globally recognized biodiversity hotspot in southwestern Australia. We describe a variety of changes to key taxonomic groups and system-scale characteristics as a consequence of environmental change (climate and land use), and outline strategies for conserving and restoring important ecological and agricultural characteristics. Opportunities for conservation and economic adaptation are substantial because of gradients in rainfall, temperature, and land use, extensive areas of remnant native vegetation, the ability to reduce and ameliorate areas affected by secondary salinization, and the existence of large national parks and an extensive network of nature reserves. Opportunities presented by the predicted environmental changes encompass agricultural as well as natural ecosystems. These may include expansion of aquaculture, transformation of agricultural systems to adapt to drier autumns and winters, and potential increases in spring and summer rain, carbon-offset plantings, and improving the network of conservation reserves. A central management dilemma is whether restoration/preservation efforts should have a commercial or biodiversity focus, and how they could be integrated. Although the grand challenge is conserving, protecting, restoring, and managing for a future environment, one that balances economic, social, and environmental values, the ultimate goal is to establish a regional culture that values the unique regional environment and balances the utilization of natural resources against protecting remaining natural ecosystems

    Explaining the rank order of invasive plants by stakeholder groups

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    Debates surrounding the use of policies to avoid further spread of invasive species highlight the need to establish priorities in public resource allocations. We explore the consistency or discrepancy among stakeholder groups involved in the risk and control management of invasive species to identify the extent to which different factors influence stakeholder choices of major relevant plant invaders. Based on stakeholder ranking of invasive plants, we explore the reasons behind stakeholders' support for policy management. Data were collected in Galicia, Spain, where a catalogue of prohibited entry and trade of invasive species is currently under debate. We estimate a rank ordered logit model using information from semi-structured interviews conducted with respondents from four stakeholder groups: public administration sector, ornamental sector, research and social groups. The characteristics of plant invaders that provoke stakeholders to rank a species more highly are wide distribution of plant invaders, existence of public control programmes, use and sale of species in the ornamental sector and media coverage. The influence these aspects have in the selection of top-ranked invaders varies across different stakeholder groups and with stakeholders' level of knowledge, awareness and attitudes towards different potential policy measures. A small group of invaders are perceived as top rated by all stakeholder groups

    Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.

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    Telomere length is a risk factor in disease and the dynamics of telomere length are crucial to our understanding of cell replication and vitality. The proliferation of whole genome sequencing represents an unprecedented opportunity to glean new insights into telomere biology on a previously unimaginable scale. To this end, a number of approaches for estimating telomere length from whole-genome sequencing data have been proposed. Here we present Telomerecat, a novel approach to the estimation of telomere length. Previous methods have been dependent on the number of telomeres present in a cell being known, which may be problematic when analysing aneuploid cancer data and non-human samples. Telomerecat is designed to be agnostic to the number of telomeres present, making it suited for the purpose of estimating telomere length in cancer studies. Telomerecat also accounts for interstitial telomeric reads and presents a novel approach to dealing with sequencing errors. We show that Telomerecat performs well at telomere length estimation when compared to leading experimental and computational methods. Furthermore, we show that it detects expected patterns in longitudinal data, repeated measurements, and cross-species comparisons. We also apply the method to a cancer cell data, uncovering an interesting relationship with the underlying telomerase genotype

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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