Tree species can influence biogeochemistry through variation in the quantity and chemistry of their litter, and associated impacts on the soil heterotrophic community. However, the role that different plant traits play in these processes is not well understood, nor is it clear whether species effects on soils largely reflect a gymnosperm vs. angiosperm contrast. Using a replicated, long-term monoculture plot experiment, we examined variation in soils among 14 gymnosperm and angiosperm tree species 30 years after plot establishment, and assessed the role of litter chemistry vis-à-vis such variation. Differences in litter calcium concentrations among tree species resulted in profound changes in soil acidity and fertility that were similar within and among tree groups. Tree species rich in calcium were associated with increased native earthworm abundance and diversity, as well as increased soil pH, exchangeable calcium, per cent base saturation and forest floor turnover rate.

Background: Several studies have highlighted that volatile anaesthetics improve myocardial protection in cardiopulmonary bypass coronary surgery. However, the haemodynamic effect of desflurane in off-pump coronary surgery has not been clarified yet. Our study hypothesis was that desflurane-fentanyl anaesthesia could decrease myocardial injury markers and improve haemodynamics compared to propofol-fentanyl in patients undergoing off-pump coronary surgery. Methods: Design: Prospective randomised open-label study. Sixty elective patients with left ventricular ejection fraction above 30% received either desflurane (group D, n = 32) or propofol (group P, n = 28), in addition to fentanyl and vecuronium bromide anaesthesia for off-pump coronary surgery. Assessment of haemodynamic function included thermodilution continuous cardiac output and right ventricular end diastolic volume. Results: No significant differences in cardiac output, stroke volume and mean arterial pressure were noted between groups. The only observed difference in haemodynamic profile was that group D demonstrated improved stability, expressed as left ventricular stroke work index (LVSWI). Decrease in LVSWI after performing distal anastomoses was smaller in D compared to P (median value: -14.3 and -19.8 [g m m -2 beat -1 ]), respectively (P = 0.029). Oxygen uptake index (VO 2 I) and oxygen extraction ratio (OER) after skin incision were lower in D, while blood lactate concentration was slightly higher after surgery in D compared to P. The groups did not differ with respect to CK-MB and troponin I concentration. Conclusions: This study demonstrated no difference between desflurane and propofol anaesthesia for off-pump coronary surgery in major haemodynamic parameters, as well as in myocardial injury markers and the long-term outcome. However, the study indicated that desflurane might accelerate recovery of myocardial contractility, as assessed by LVSWI. Lower oxygen uptake and elevated lactate under desflurane anaesthesia indicated a discrete shift towards anaerobic metabolism. Clinical trial registration information: NCT00528515

We conclude that the heart is not the main source of IL-8 in early coronary reperfusion, although coronary reperfusion induces its release.

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