59 research outputs found
Climatic regions as an indicator of forest coarse and fine woody debris carbon stocks in the United States
<p>Abstract</p> <p>Background</p> <p>Coarse and fine woody debris are substantial forest ecosystem carbon stocks; however, there is a lack of understanding how these detrital carbon stocks vary across forested landscapes. Because forest woody detritus production and decay rates may partially depend on climatic conditions, the accumulation of coarse and fine woody debris carbon stocks in forests may be correlated with climate. This study used a nationwide inventory of coarse and fine woody debris in the United States to examine how these carbon stocks vary by climatic regions and variables.</p> <p>Results</p> <p>Mean coarse and fine woody debris forest carbon stocks vary by Köppen's climatic regions across the United States. The highest carbon stocks were found in regions with cool summers while the lowest carbon stocks were found in arid desert/steppes or temperate humid regions. Coarse and fine woody debris carbon stocks were found to be positively correlated with available moisture and negatively correlated with maximum temperature.</p> <p>Conclusion</p> <p>It was concluded with only medium confidence that coarse and fine woody debris carbon stocks may be at risk of becoming net emitter of carbon under a global climate warming scenario as increases in coarse or fine woody debris production (sinks) may be more than offset by increases in forest woody detritus decay rates (emission). Given the preliminary results of this study and the rather tenuous status of coarse and fine woody debris carbon stocks as either a source or sink of CO<sub>2</sub>, further research is suggested in the areas of forest detritus decay and production.</p
Drawings of very preterm-born children at 5Â years of age: a first impression of cognitive and motor development?
INTRODUCTION: The aim of this study was to examine differences in drawing skills between very preterm and term children, and to determine whether very preterm children's cognitive and motor development is reflected in the draw-a-person test (DAP) at age 5. Seventy-two very preterm children (birth weight <1,500 g and/or gestational age <32 weeks) and 60 term children at 5 years of age were compared on the DAP. Cognitive and motor skills of the very preterm children had been assessed four times, at 1/2, 1, 2, and 5 years of age. Very preterm children showed a developmental delay in drawing ability. Structural equation modeling revealed a positive relation between both cognitive as well as motor development and the DAP. CONCLUSION: The DAP could be a crude parameter for evaluating cognitive and motor deficits of very preterm children. A worrisome result should be followed by more standardized tests measuring cognitive and motor skill
Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems
Streams and rivers in mediterranean-climate regions (med-rivers in med-regions) are ecologically unique, with flow regimes reflecting precipitation patterns. Although timing of drying and flooding is predictable, seasonal and annual intensity of these events is not. Sequential flooding and drying, coupled with anthropogenic influences make these med-rivers among the most stressed riverine habitat worldwide. Med-rivers are hotspots for biodiversity in all med-regions. Species in med-rivers require different, often opposing adaptive mechanisms to survive drought and flood conditions or recover from them. Thus, metacommunities undergo seasonal differences, reflecting cycles of river fragmentation and connectivity, which also affect ecosystem functioning. River conservation and management is challenging, and trade-offs between environmental and human uses are complex, especially under future climate change scenarios. This overview of a Special Issue on med-rivers synthesizes information presented in 21 articles covering the five med-regions worldwide: Mediterranean Basin, coastal California, central Chile, Cape region of South Africa, and southwest and southern Australia. Research programs to increase basic knowledge in less-developed med-regions should be prioritized to achieve increased abilities to better manage med-rivers
Identification of Novel Genetic Loci Associated with Thyroid Peroxidase Antibodies and Clinical Thyroid Disease
Peer reviewe
Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems
Climate change impacts on groundwater recharge- uncertainty, shortcomings, and the way forward?
An integrated approach to assessing the regional impacts of climate and socio-
economic change on groundwater recharge is described from East Anglia, UK. Many
factors affect future groundwater recharge including changed precipitation and
temperature regimes, coastal flooding, urbanization, woodland establishment, and
changes in cropping and rotations. Important sources of uncertainty and
shortcomings in recharge estimation are discussed in the light of the results.
The uncertainty in, and importance of, socio-economic scenarios in exploring the
consequences of unknown future changes are highlighted. Changes to soil
properties are occurring over a range of time scales, such that the soils of the
future may not have the same infiltration properties as existing soils. The
potential implications involved in assuming unchanging soil properties are
described. To focus on the direct impacts of climate change is to neglect the
potentially important role of policy, societal values and economic processes in
shaping the landscape above aquifers. If the likely consequences of future
changes of groundwater recharge, resulting from both climate and socio-economic
change, are to be assessed, hydrogeologists must increasingly work with
researchers from other disciplines, such as socio-economists, agricultural
modellers and soil scientists
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