Variations of morphology, anatomical structure and nitrogen content among first-order roots in different positions along branch orders in tree species
LIU Ying, GU Jia-Cun, WEI Xing, XU Yang, WANG Zheng-Quan
Chin J Plant Ecol . 2010, (11): 1336 -1343 .  DOI: 10.3773/j.issn.1005-264x.2010.11.011