Abstract: The stoichiometric characteristics of fine roots in Phyllostachys edulis and its varieties (P. edulis f.luteosulcata, P. edulis f.taokiang, P. edulis f. pachyloen, P. edulis f.gracilis) at three stages (1, 3, and 5 years old) were analyzed and compared, aiming to explore nutrient use strategies of P. edulis and its varieties. The results showed that: (1) The stoichiometric characteristics of fine roots in P. edulis were varietyspecific, while age had minor effects. (2) There were differences of nutrient contents in fine roots of P. edulis and its varieties. The contents of total C, total N and total P in fine roots of P. edulis f.luteosulcata were higher than other varieties. The C∶N and C∶P of fine roots of P. edulis were larger, and no differences of fine root N∶P across P. edulis and its varieties were found. (3) Fine root N and P contents in P. edulis and P. edulis f.gracilis showed a significant allometric relationship, and the fine roots of P. edulis and its varieties were generally limited by P availability. The allometric relationships among C, N and P elements in fine roots of other bamboo species were not significant, indicating a similar nutrient allocation pattern. (4) Fine root stoichiometry and soil chemical properties were closely correlated, with the C∶P of fine roots being mainly restricted by soil organic matter and total P content. Compared with soil environmental factors, fine root stoichiometric characteristics of P. edulis and its varieties were more limited by the genetic characteristics of bamboo species. The stoichiometric characteristics of fine roots of P. edulis and its varieties were affected by their growth stage. The nutrient use strategies differed across bamboo species.

Key words: variety, age, carbon, nitrogen and phosphorus concentration, allometric growth relationship, nutrient strategy.