18 research outputs found

    Projections of global and UK bioenergy potential from Miscanthus x giganteus – feedstock yield, carbon cycling and electricity generation in the 21st century

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    Funding Information Natural Environment Research Council. Grant Numbers:NE/M019691/1, NE/P019951/1 Engineering and Physical Sciences Research CouncilPeer reviewedPublisher PD

    Climatic controls on peatland black spruce growth in relation to water table variation and precipitation

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    Prior research has demonstrated the importance of water limitations and increasing temperatures on upland black spruce (Picea mariana [Mill.] B.S.P.) tree growth, which is a dominant component of the North American boreal forest. However, little work has been done to investigate the connectivity between growth and hydro‐climate in peatland black spruce systems. The boreal forest is the largest global terrestrial biome and is highly threatened due to current and projected increases in temperatures for the northern latitudes. Here we explore the dynamics among annual black spruce growth, climate, and water table elevations using 45 years of in situ precipitation, temperature, and water table elevation coupled with dendrochronological analysis from six research peatlands at the Marcell Experimental Forest, MN, USA. From 1963 to 2010, we found weak relationships between water table elevation and black spruce growth at the six study sites. Instead, annual black spruce growth was most favourable during three climatic periods: (a) cool, moist conditions in mid‐summer; (b) warm mid‐spring temperatures; and (c) cool temperatures in the fall prior to the current growing season. The disconnect between black spruce growth and water table dynamics was surprising and suggests that either annual black spruce growth is minimally responsive to hydrological fluctuations at the timescale we analysed or there is great elasticity of black spruce growth to peatland water table and evapotranspiration dynamics under the range of hydrological fluctuations contained in our record

    Taxonomic and functional turnover are decoupled in European peat bogs

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    In peatland ecosystems, plant communities mediate a globally significant carbon store. The effects of global environmental change on plant assemblages are expected to be a factor in determining how ecosystem functions such as carbon uptake will respond. Using vegetation data from 56 Sphagnum-dominated peat bogs across Europe, we show that in these ecosystems plant species aggregate into two major clusters that are each defined by shared response to environmental conditions. Across environmental gradients, we find significant taxonomic turnover in both clusters. However, functional identity and functional redundancy of the community as a whole remain unchanged. This strongly suggests that in peat bogs, species turnover across environmental gradients is restricted to functionally similar species. Our results demonstrate that plant taxonomic and functional turnover are decoupled, which may allow these peat bogs to maintain ecosystem functioning when subject to future environmental change

    Gene expression in the prefrontal cortex during adolescence: implications for the onset of schizophrenia

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    <p>Abstract</p> <p>Background</p> <p>Many critical maturational processes take place in the human brain during postnatal development. In particular, the prefrontal cortex does not reach maturation until late adolescence and this stage is associated with substantial white matter volume increases. Patients with schizophrenia and other major psychiatric disorders tend to first present with overt symptoms during late adolescence/early adulthood and it has been proposed that this developmental stage represents a "window of vulnerability".</p> <p>Methods</p> <p>In this study we used whole genome microarrays to measure gene expression in post mortem prefrontal cortex tissue from human individuals ranging in age from 0 to 49 years. To identify genes specifically altered in the late adolescent period, we applied a template matching procedure. Genes were identified which showed a significant correlation to a template showing a peak of expression between ages 15 and 25.</p> <p>Results</p> <p>Approximately 2000 genes displayed an expression pattern that was significantly correlated (positively or negatively) with the template. In the majority of cases, these genes in fact reached a plateau during adolescence with only subtle changes thereafter. These include a number of genes previously associated with schizophrenia including the susceptibility gene neuregulin 1 (NRG1). Functional profiling revealed peak expression in late adolescence for genes associated with energy metabolism and protein and lipid synthesis, together with decreases for genes involved in glutamate and neuropeptide signalling and neuronal development/plasticity. Strikingly, eight myelin-related genes previously found decreased in schizophrenia brain tissue showed a peak in their expression levels in late adolescence, while the single myelin gene reported increased in patients with schizophrenia was decreased in late adolescence.</p> <p>Conclusion</p> <p>The observed changes imply that molecular mechanisms critical for adolescent brain development are disturbed in schizophrenia patients.</p

    Land use and management effects on soil carbon in U.S. Lake States, with emphasis on forestry, fire, and reforestation

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    There is growing need to quantify and communicate how land use and management activities influence soil organic carbon (SOC) at scales relevant to, and in the tangible control of landowners and forest managers. The continued proliferation of publications and growth of data sets, data synthesis and meta-analysis approaches allows the application of powerful tools to such questions at ever finer scales. In this analysis, we combined a literature review and effect-size meta-analysis with two large, independent, observational databases to assess how land use and management impact SOC stocks, primarily with regards to forest land uses. We performed this work for the (Great Lakes) U.S. Lake States, which comprise 6% of the land area, but 7% of the forest and 9% of the forest SOC in the United States, as the second in a series of ecoregional SOC assessments. Most importantly, our analysis indicates that natural factors, such as soil texture and parent material, exert more control over SOC stocks than land use or management. With that for context, our analysis also indicates which natural factors most influence management impacts on SOC storage. We report an overall trend of significantly diminished topsoil SOC stocks with harvesting, consistent across all three data sets, while also demonstrating how certain sites and soils diverge from this pattern, including some that show opposite trends. Impacts of fire grossly mirror those of harvesting, with declines near the top of the profile, but potential gains at depth and no net change when considering the whole profile. Land use changes showing significant SOC impacts are limited to reforestation on barren mining substrates (large and variable gains) and conversion of native forest to cultivation (losses). We describe patterns within the observational data that reveal the physical basis for preferential land use, e.g., cultivation of soils with the most favorable physical properties, and forest plantation establishment on the most marginal soils, and use these patterns to identify management opportunities and considerations. We also qualify our results with ratings of confidence, based on their degree of support across approaches, and offer concise, defensible tactics for adapting management operations to site-specific criteria and SOC vulnerability

    Introducing climate change into the biochemistry and molecular biology curriculum

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    Our climate is changing due to anthropogenic emissions of greenhouse gases from the production and use of fossil fuels. Present atmospheric levels of CO2 were last seen 3 million years ago, when planetary temperature sustained high Arctic camels. As scientists and educators, we should feel a professional responsibility to discuss major scientific issues like climate change, and its profound consequences for humanity, with students who look up to us for knowledge and leadership, and who will be most affected in the future. We offer simple to complex backgrounds and examples to enable and encourage biochemistry educators to routinely incorporate this most important topic into their classrooms
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