关键词: 堆腐系统, 循环率, 有机肥N、P利用率

Abstract: In this study, open-top chambers (OTCs) were employed to approach the impacts of elevated atmospheric ozone (O₃) concentration on the photosynthesis of Phyllostachys edulis. Five treatments were installed, i.e., CF (background atmosphere after filtrated by activated carbon, 22-25 nL·L^-1), NF (directly introduce the background atmosphere to the gas chamber, 40-45 nL·L^-1), T₁ (92-106 nL·L^-1 of O₃, averagely 100 nL·L^-1), T₂ (142-160 nL·L^-1 of O₃, averagely 150 nL·L^-1). Under different O₃ concentrations, the diurnal variations of P. edulis leaf P_n and T_r represented onepeak curves. With the increasing concentration of O₃, the diurnal variations of the leaf G_s, C_i, and L_s trended to be simplified, while that of WUE became stable gradually. Under higher concentrations (≥ 100 nL·L^-1) O₃, the diurnal means of P_n, L_s, and WUE and the contents Chl, Chl-a, Chl-b, and Car decreased significantly, those of G_s and T_r had a significant increase, while the diurnal mean of C_i and the composition of photosynthetic pigment changed less. In treatments T₁ and T₂, the P_n,T_r, and G_s were significantly correlated with the environmental factors V_pdL, T_air, C_a, and RH, and the P_n and T_r were significantly correlated with the PPED while the G_s was less correlated with the PPED. All the results indicated that 100 and 150 nL·L^-1 of O₃ could induce the leaf stomatal or nonstomatal limitation of P. edulis, respectively, and the stoma became insensitive to the environment, which impacted the leaf’s normal feedback mechanisms, increased leaf evapotranspiration, and inhibited the degradation or synthesis of photosynthetic pigments, exerting serious negative effects on the photosynthesis and dry matter accumulation of P. edulis.