Bomb-¹⁴C analysis of ecosystem respiration reveals that peatland vegetation facilitates release of old carbon

The largest terrestrial-to-atmosphere carbon flux is respired CO<sub>2</sub>. However, the partitioning of soil and plant sources, understanding of contributory mechanisms, and their response to climate change are uncertain. A plant removal experiment was established within a peatland located in the UK uplands to quantify respiration derived from recently fixed plant carbon and that derived from decomposition of soil organic matter, using natural abundance <sup>13</sup>C and bomb-<sup>14</sup>C as tracers. Soil and plant respiration sources were found respectively to contribute ~ 36% and between 41-54% of the total ecosystem CO<sub>2</sub> flux. Respired CO<sub>2</sub> produced in the clipped (‘soil’) plots had a mean age of ~ 15 years since fixation from the atmosphere, whereas the <sup>14</sup>C content of ecosystem CO<sub>2</sub> was statistically indistinguishable from the contemporary atmosphere. Results of carbon mass balance modelling showed that, in addition to respiration from bulk soil and plant respired CO<sub>2</sub>, a third, much older source of CO<sub>2</sub> existed. This source, which we suggest is CO<sub>2</sub> derived from the catotelm constituted between ~ 10 and 23% of total ecosystem respiration and had a mean radiocarbon age of between several hundred to ~ 2000 years before present (BP). These findings show that plant-mediated transport of CO<sub>2</sub> produced in the catotelm may form a considerable component of peatland ecosystem respiration. The implication of this discovery is that current assumptions in terrestrial carbon models need to be re-evaluated to consider the climate sensitivity of this third source of peatland CO<sub>2</sub>

Clinical psychology for cardiac disease

From its very beginning, modern scientific psychology has dealt with issues regarding mind-body, health-disease relationships; in particular, clinical psychology, in its various applications, has tried to provide a structure to psychological concepts tied to organic disease. Clinical psychology is described as the “area of psychology whose objectives are the explanation, understanding, interpretation and reorganization of dysfunctional or pathological mental processes, both individual and interpersonal, together with their behavioral and psychobiological correlates” [2]. Clinical psychology is characterized by a variety of models, methods, theories and techniques, each of which has its own historical reason. Its core and indispensable common denominator is clinical practice, be it intended for individuals, groups or collectives [3]. Among its areas of application we can include psychosomatics, health psychology and hospital psychology, where clinical psychology offers a relevant and coherent scientific, professional and training frame through contributions aimed at health maintenance and promotion, identification of etiological and diagnostic correlates, analysis and improvement of health care, and enhancement of public health [4]