长白山不同海拔白桦幼苗移栽至同一生境的光合及反射光谱特性

环境是影响植物生理性状的主要因素之一,通过改变植物的生长环境来研究植物生理性状的改变是目前研究植物生理生态的热点,而高海拔地区多样的环境为研究物种适应环境变化提供了良好的实验条件。本研究通过移栽的技术手段,将分布在海拔750 m、海拔1200 m和海拔1400 m的3~5年生白桦幼苗移植到海拔750 m相同的林下环境条件下,将3种白桦移栽幼苗和野生白桦幼苗的光响应参数、光谱反射率以及光谱反射指数进行对比研究,分析移栽初期和移栽一年后植物生理性状的异同,探索白桦幼苗迁入新环境的适应性。研究结果表明:移栽初期,通过对比不同海拔来源的白桦移栽幼苗彼此之间各项生理性状以及与原海拔野生白桦幼苗的生理性状发现,包括最大净光合速率(A_(max))、气孔导度(G_s)、胞间CO_2浓度(C_i)在内的生理性状差异显著(P0.05),幼苗光谱反射指数差异性显著(P0.05)。经过一年的适应,不同海拔来源的白桦幼苗与移栽地海拔750 m野生白桦幼苗的生理性状之间差异不显著(P0.05),幼苗光谱反射指数差异性不显著(P0.05),而与原海拔野生幼苗生理性状之间差异显著(P0.05),幼苗光谱反射指数差异显著(P0.05)。在移栽初期,移栽幼苗的各项生理指标已经因环境的改变而发生变化,但仍保留原海拔野生幼苗的生理特性;移栽一年后,移栽幼苗逐渐适应环境,其相关生理性状发生改变,并趋同于移栽地野生白桦幼苗的生理性状。对比一个生长季前后白桦移栽幼苗生理性状的变化可以发现,白桦作为先锋种植物,在新迁入环境后具有良好的环境适应性,能通过调整生理性状适应新环境。研究对幼苗在林下的演替以及森林的更新具有借鉴意义。

Characteristics of photosynthesis and spectral reflectance in Betula platyphylla from different altitudes transplanted to the same habit on the Changbai Mountain

Environment is one of the main factors which influences the physiological characters. By changing the growing environment of plants to study the change of plant physiological characters is the hotpot of physiological ecological research, while high altitude areas with vary environments provide a good condition for the study of species to adapt to new environments. This research compared the light response parameters, spectral reflectance, and spectral reflectance indices of three Betula platyphylla seedlings from different altitude and a single common altitude on the Changbai Mountain by means of transplanting ages from 3 to 5 years of Betula platyphylla seedlings from altitudes of 750 m,1200 m and 1400 m to the same altitude of 750 m to analyze the differences and similarities of physiological and ecological characteristics between the initial stage and 1 year after transplantation, and to explore the adaption of Betula platyphylla seedlings to the new environment. The research showed that by comparing the physiological characters among different sources of elevation of Betula platyphylla transplanting seedlings as well as wild Betula platyphylla seedlings of the original elevation, the physiological traits of different Betula platyphylla seedlings including net photosynthetic rate(A_max), stomatal conductance(G_s), and intercellular CO₂ concentration(C_i) were significantly different(P < 0.05) and spectral reflectance index were also significant difference(P < 0.05) in the early of transplantation.After a growing season, the physiological traits between Betula platyphylla seedlings from different altitudes and Betula platyphylla seedlings from situ altitude of 750 m were not significant difference (P > 0.05), as well the spectral reflectance index (P > 0.05), but the physiological traits between Betula platyphylla seedlings from different altitudes and Betula platyphylla seedlings from situ altitude of 1200 m and 1400 m were significant difference (P < 0.05), Similarly, there were no significant differences in spectral reflectance index(P < 0.05).The research shows that various physiological indicators of Betula platyphylla seedlings had changed due to the change of environment, but seedlings still retained the original physiological characteristics of the situ wild Betula platyphylla seedlings in the early of transplanting; After a growing season, the transplanting Betula platyphylla seedlings gradually adopt to the new environment and the related physiological characters has changed, which means the physiological characters of the transplanting Betula platyphylla seedlings have convergence with the wild Betula platyphylla seedlings. By comparing the change of physiological characters before and after the growing seasons, the research shows that as a pioneer plant, when Betula platyphylla seedlings transplant to new environment, they are highly adaptive to their environment, which means they can adjust the physiological characters to adapt to the new environment. The significance of this study is to provide reference significance for succession of seedlings and forest regeneration.