Links between root carbohydrates and seasonal pattern of soil microbial activity of diverse European populations of Pinus sylvestris grown in a provenance plantation

Activity of soil dehydrogenase (DHA) was measured in the mineral soil in a forest stand of 15 to 16-year-old Scots pine (Pinus sylvestris L.) from geographically diverse populations, as an indicator of biological activity of soil microorganisms, in a provenance experiment in Poland. The pine populations originated from six European countries (Sweden, Russia, Latvia, Poland, Germany, France) and differed widely in aboveground biomass and productivity. Soil DHA during two growing seasons showed pronounced seasonal variability, which was significantly related to the fine root concentration of nonstructural carbohydrates. Higher DHA was found in soil under canopies of the central and southern European populations than in those from more northern parts of the Scots pine range. Significant positive correlation between soil DHA and aboveground tree biomass suggest that these patterns most likely resulted from differences in carbon dynamics and productivity among populations.