黄土丘陵区5种主要乔灌树种光合生理生态特征

(1.西北农林科技大学 水土保持研究所 黄土高原土壤侵蚀与旱地农业国家重点实验室, 陕西 杨凌 712100; 2.水利部 黄河水利委员会 黄河上中游管理局, 西安 710021; 3.西北农林科技大学 林学院, 陕西 杨凌 712100; 4.中国科学院 水利部 水土保持研究所, 陕西 杨凌 712100; 5.陕西省安康市汉滨区水利局, 陕西 安康 725000)

光合生理参数; 日变化规律; Pearson相关分析; 生理生态因子; 黄土丘陵区

Photosynthetic Physiological and Ecological Characteristics of 5 Main Forest & Shrub Stands in Loess Hilly Region
QIAO Yuning1,2, REN Jingyu2, WEI Sihan3, CHEN Yunming1,4, WU Rui3

(1.State key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China; 2.Upper and Middle Yellow River Bureau, YRCC,MWR, Xi'an 710021, China; 3.College of Forestry, Northwest A&F University,Yangling, Shaanxi 712100, China; 4.Institute of Soil and Water Conservation, CAS & MWR, Yangling, Shaanxi 712100, China; 5.Water Conservancy Bureau of Hanbin, Ankang, Shaanxi 725000, China)

photosynthetic physiological parameter; daily variation curve; pearson correlative analysis; eco-physiological factors; loess hilly region

备注

为阐释5种乔灌树种光合生理参数变化特征,采用LI-6400XT对光合生理参数进行测定,收集土壤水分及气象因子数据,得出光合生理特性日变化规律及日累积量差异性,剖析了其与影响因子的关系。结果表明:(1)连翘及紫穗槐净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)及气孔限制值(Ls)日变化表现出“双峰”与“单峰”变化规律,且峰值集中在10:00与14:00,侧柏Pn及水分利用效率(WUE)呈现单调递减的趋势;(2)不同树种间光合生理参数差异性主要表现为灌木的Pn,Tr,WUE,Gs日累积量高于乔木,其中紫穗槐、丁香各项参数明显优于其余树种,侧柏除了胞间CO2浓度(Ci)日累积量较大外,其余各参数累积量均显著低于其余树种;(3)各树种Pn与Gs相关程度最高且呈正比,Tr与Ci、大气CO2浓度(Ca)、空气相对湿度(RH)呈反比; 浅层土壤水分(20,50 cm)与侧柏、连翘、丁香Pn,Tr表现出正相关性,深层土壤水分(120,150 cm)与丁香、紫穗槐光合蒸腾关系紧密,其中紫穗槐在二者间呈现相反的变化趋势。上述结果说明,在黄土丘陵区,紫穗槐环境适应性最强,适合作为该区主要生态恢复灌木树种,油松水分利用效率较高,适合作为该区主要抗旱乔木树种。
In order to explain the change characteristics of photosynthetic physiological parameters of five tree and shrub species, LI-6400XT was used to measure photosynthetic physiological parameters, and data of soil moisture and meteorological factors were collected. The diurnal changes of photosynthetic physiological characteristics and differences in daily accumulation were obtained, and the differences were analyzed. The relationship between impact factors and photosynthetic physiological parameters were analyzed. The results showed that:(1)the daily changes of net photosynthetic rate(Pn), transpiration rate(Tr), stomatal conductance(Gs)and stomatal limit value(Ls)Forsythia suspensa and Amorpha fruticosa showed the patters of double peaks and single peaks, and the peaks concentrated at 10:00 and 14:00; the Pn of Platycladus orientalis and water use efficiency(WUE)showed a monotonous decreasing trend;(2)the difference in photosynthetic physiological parameters between different species showed that the daily accumulation of Pn, Tr, WUE and Gs of shrubs was higher than that of trees, among which the parameters of Amorpha fruticosa and Syzygium aromaticum were significantly better than those of other tree species; except for the large daily accumulation of intercellular CO2 concentration(Ci)of Platycladus orientalis, the accumulation of other parameters was significantly lower than that of other tree species;(3)the correlation between Pn and Gs of each tree species was the highest and proportional, and Tr was inversely proportional to Ci, atmospheric CO2 concentration(Ca)and air relative humidity(RH); shallow soil moisture(20, 50 cm)showed a positive correlation with Pn and Tr of Platycladus orientalis, Forsythia suspensa, Syzygium aromaticum, deep soil moisture(120, 150 cm)was closely related to photosynthesis and transpiration of Syzygium aromaticum and Amorpha fruticosa, among which Amorpha fruticosa presented an opposite change trend. The above results indicated that Amorpha fruticosa had the strongest environmental adaptability and was suitable for being main ecological restoration shrub species in the loess hilly region, while Pinus tabuliformis had higher water use efficiency and was suitable for being main drought-resistant tree species in this region.