Nutrient concentrations in fine roots

Fine roots are an important source and sink for nutrients in terrestrial biogeochemistry. We examined the following hypotheses for fine root nutrients by analyzing data from 56 published studies: (1) that there is a general, inverse relationship of fine root nutrient concentrations with root diameter, and (2) that retranslocation of nutrients out of fine roots is minimal. We analyzed nutrient concentrations of roots ≤ 5 mm in diameter as a function of root diameter and root status (live, dead, and undifferentiated), including a comparison for coniferous and broad-leaved trees. For fine roots