Land‐use change from cropland to orchard leads to high nitrate accumulation in the soils of a small catchment

Land‐use change from cereals to fruit orchards usually results in a high nutrient surplus in soil. The excessive accumulation of nitrogen (N) in soil, mainly as nitrate, leached from the root zone may serve as a long‐term source of surface or groundwater pollution. The N balances and nitrate accumulation in the soil profiles of cereal fields and kiwifruit orchards in the Yujiahe catchment, Shaanxi, China, were compared. Excessive N fertilisation resulted in an excessive N surplus (1,133 kg N ha−1 yr−1) in orchards (8‐times higher than that in cereal fields). More than 77.5% of nitrate in the soil profile (0–400 cm) of the orchards was below a soil depth of 100 cm. The average accumulated nitrate within a profile 0–400 cm of orchards was 3,288 kg N ha−1, which was 16‐fold higher than that of cereal fields. The accumulated nitrate in soil profiles on the downslope (5,959 kg N ha−1) was approximately 2 times higher than that of the upslope in the same sloping orchards. The accumulated nitrate in soil profiles at the lowland zone of the catchment was higher than that of the upland zone. Excessive nitrate moves not only vertically downwards to deeper soil depth but also laterally into lower elevations at both field and catchment scales. The total stored nitrate in the upper soil profile of 400 cm in the catchment was 464.8 Mg N, whereas 94.8% (440.8 Mg N) was in orchards. Thus, changing land use from cereal crops to orchards leads to a high nitrate accumulation in the catchment

Rapid progress on the vertebrate tree of life

<p>Abstract</p> <p>Background</p> <p>Among the greatest challenges for biology in the 21st century is inference of the tree of life. Interest in, and progress toward, this goal has increased dramatically with the growing availability of molecular sequence data. However, we have very little sense, for any major clade, of how much progress has been made in resolving a full tree of life and the scope of work that remains. A series of challenges stand in the way of completing this task but, at the most basic level, progress is limited by data: a limited fraction of the world's biodiversity has been incorporated into a phylogenetic analysis. More troubling is our poor understanding of what fraction of the tree of life is understood and how quickly research is adding to this knowledge. Here we measure the rate of progress on the tree of life for one clade of particular research interest, the vertebrates.</p> <p>Results</p> <p>Using an automated phylogenetic approach, we analyse all available molecular data for a large sample of vertebrate diversity, comprising nearly 12,000 species and 210,000 sequences. Our results indicate that progress has been rapid, increasing polynomially during the age of molecular systematics. It is also skewed, with birds and mammals receiving the most attention and marine organisms accumulating far fewer data and a slower rate of increase in phylogenetic resolution than terrestrial taxa. We analyse the contributors to this phylogenetic progress and make recommendations for future work.</p> <p>Conclusions</p> <p>Our analyses suggest that a large majority of the vertebrate tree of life will: (1) be resolved within the next few decades; (2) identify specific data collection strategies that may help to spur future progress; and (3) identify branches of the vertebrate tree of life in need of increased research effort.</p

Influence of Psychological Factors on Pain and Disability in Anterior Knee Pain Patients

AKP patients express chronic pain but also disability. However, the correlation between pain and disability is not complete and linear. Some patients with a lot of pain show mild disability while others with much less pain also show great disability. The disability is profoundly influenced by other emotional and cognitive factors that are associated with the perception of pain. Therefore, the clinical efforts do not have to be focused only on treating the pain as a feeling but on identifying and modifying these factor