Objective To provide theoretical basis for vegetation restoration in Taihang Mountain, the study discussed different adaptation strategies of Quercus variabilis, Robinia pseudoacacia and Platycladus orientalis to drought from perspective of hydraulic architecture.

Method Based on Quercus variabilis (38-year-old), Robinia pseudoacacia (42-year-old) and Platycladus orientalis (30-year-old) in Taihang Mountain, Native sapwood specific hydraulic conductivity (K_s) and maximum specific hydraulic conductivity (K_smax) of perennial stems were measured by using a Pipette. Percent loss of hydraulic conductivity (PLC) of Quercus variabilis and Robinia pseudoacacia were measured by flushing method, and PLC of Platycladus orientalis was measured by vacuum method. Wood anatomy was measured by using optical microscope and scanning electron microscope technology.

Result (1) The mean vessel diameter (D_v), hydraulic weighted vessel diameter (D_h) and aperture fraction (F_ap), number of pits per unit area of vessel wall (N_p), total pit area per vessel area (F_a) of Quercus variabilis and Robinia pseudoacacia were all significant higher than those of Platycladus orientalis. K_s and PLC of the former two deciduous tree species were therefore significantly higher than those of Platycladus orientalis; (2) The D_v, D_h, surface area of inter-vessel pit membranes (A_p), area of single pit aperture (A_ap), F_ap, N_p and F_a of Robinia pseudoacacia were significantly higher than those of Quercus variabilis. However, PLC of Robinia pseudoacacia was significantly lower than that of Quercus variabilis, which might be due to the fact that the pit chamber and pit aperture of Robinia pseudoacacia had punctate and dentate vestures, which enhanced resistance to drought induced cavitation. (3) The A_ap , F_a and F_ap increased with the increase in the diameter of the xylem vessels of the three tree species.

Conclusion Quercus variabilis and Robinia pseudoacacia have high xylem water transport efficiency, which indicates that they employ fast growth strategy. While Platycladus orientalis adopts conservative resource acquisition strategy with lower xylem water transports efficiency. The xylem vessels and pit structures synergistically affect xylem water transport efficiency and resistance to drought-induced cavitation, and xylem anatomy is an important trait determining the adaptation strategies of different tree species to arid environments.