Root inclusion net method: novel approach to determine fine root production and turnover in Larix principis-rupprechtii Mayr plantation in North China

摘要

A novel root inclusion net method was designed to determine the fine root productions and turnover rates of 13-, 22-, and 38-year-old Larix principis-rupprechtii plantations in the whole growing season of 2012, and it was compared with the results ofthe sequential coring method and in-growth core method. All following values are reported in order for 13-, 22-, and 38-year-old L. principis-rupprechtii plantations. The mean values of fine root biomasses were 103, 261, and 356 g m~(-2), about 76-78% ofwhich were live fine root biomasses. The fine root productions were 86-118 g m~(-2) year~(-1),124-138 g m~(-2) year~(-1), and 134-160 g m~(-2) year~(-1), respectively. The fine root turnover rates were 1.12, 0.61, and 0.51 times year~(-1), respectively,suggesting a relative slow fine root turnover in L. principis-rupprechtii plantations. The carbon inputs into soil accompanying fine root turnover were 52, 58, and 94 g C nr2 year~(-1). This organic carbon is a sizeable pool in the forest ecosystem. Theresults suggest that our new modified root inclusion net method is suitable for field-based assessment of fine root production and turnover.