Dataset: Canopy Nitrogen addition promotes xylem formation of Castanopsis chinensis (Sprengel) Hance in a subtropical forest in China

Increased atmospheric nitrogen (N) deposition caused by intensive anthropogenic activities resulted in inconsistent effects on the xylem formation of trees, in N-limited boreal and temperate forests. However, the effects of N deposition on xylem formation of trees in subtropical forests, are still poorly understood. The aims of the study were to (i) characterize the dynamics of xylem formation in C. chinensis in a subtropical forest in China and (ii) determine the effect on xylem formation of adding N to the canopy. From 2013-2016, 50 kg N ha-1 yr-1 was applied over the canopy of C. chinensis at the end of each month (April to October) in a subtropical forest in southern China. Then, the dynamics of xylem formation including the width of cambium cells, enlargement cells, wall-thickening cells and mature cells were monitored during 2015 and 2016 using a microcore sampling approach.