论文部分内容阅读
近年发现宝天曼锐齿栎(Quercus aliena var.acuteserrata)成熟林难以更新,通过对锐齿栎幼苗不同遮阴处理下生长、非结构性碳(NSC)和光合作用进行研究,为理解宝天曼锐齿栎树种的更新困难和加强锐齿栎林的科学抚育提供理论依据。本研究通过搭建遮阴棚对盆栽锐齿栎幼苗设置遮阴处理,并用中午开放遮阴网的方法模拟光斑,设置了对照(自然光照)、遮阴80%中午开放1 h(T80-1)、一直遮阴80%(T80)、遮阴98%中午开放1 h(T98-1)、一直遮阴98%(T98)5处理,测定了遮阴后锐齿栎幼苗的干物质量、比叶面积、NSC浓度、存活率、光合光响应曲线参数、光合日变化、荧光参数等指标。结果表明:遮阴处理的幼苗干物质量和NSC浓度都显著低于对照,模拟光斑处理使幼苗NSC浓度显著高于一直遮阴处理的幼苗;遮阴严重的T98处理使幼苗出现了较高的死亡率;在高光强下,T80、T98-1、T98的净光合速率(P_n)因非气孔限制显著低于对照;且T98的光化学反应能力最低;遮阴后锐齿栎幼苗表现出一定的遮阴适应性,如光饱和点(LCP)和暗呼吸速率(R_d)降低,T98的P_n高于T98-1。本研究证明,在严重遮阴环境下锐齿栎幼苗易因难以维持碳的收支平衡而死亡,但光斑缓解了遮阴对幼苗碳储备的不利影响,对塑造幼苗在高光照条件下的光合能力也有显著作用。
In recent years, it has been found that the mature forest of Quercus aliena var. Acuteserrata can not be renewed. Based on the study of growth, non-structural carbon (NSC) and photosynthesis under different shading treatments, Man sharptooth oak tree regeneration difficulties and strengthen the sharpening oak forest science provide the theoretical basis. In this study, shady plants were set up to shade the seedlings of Cercidiptera cantoniensis and the shading net was opened at noon to simulate the light spot. The control (natural light) was set up. The shade was 80% open at noon for 1 h (T80-1) , Shading 80% (T80), shading 98% at noon for 1 h (T98-1) and shading 98% (T98) 5. Area, NSC concentration, survival rate, photosynthetic light response curve parameters, photosynthetic diurnal changes, fluorescence parameters and other indicators. The results showed that shading treatment of seedling dry matter content and NSC concentrations were significantly lower than the control, simulated light spot treatment so that seedling NSC concentration was significantly shaded than the shade of seedlings; shady T98 treatment of seedling emergence of higher mortality The net photosynthetic rate (P_n) of T80, T98-1 and T98 was significantly lower than that of the control due to the non-stomata limitation under high light intensity, and the photochemical reaction ability of T98 was the lowest. After shading, the shading showed a certain shade Adaptability, such as decreased light saturation point (LCP) and dark respiration rate (R_d), was higher for P98 than for T98-1. This study demonstrated that the seedlings of A. sharpenii died easily under the condition of severe shading, but the light spots relieved the adverse effects of shading on the seedling carbon storage, and the photosynthesis of seedlings under high light Capacity also has a significant effect.