摘要
了解植物光合作用参数季节动态及其与叶性状的关系对于准确模拟生态系统碳循环具有重要的意义。本研究在生长季内原位测定了毛乌素沙地油蒿(Artemisia ordosica)光合作用CO_2响应和光响应曲线,分析了油蒿光合参数与叶氮含量(N_(mass))和比叶面积(SLA)的关系。结果表明:整个生长季内油蒿最大净光合速率(P_(nmax))、表观量子效率(α)和光饱和点(LSP)都是在春季后期和初秋时期值比较高,在夏季波动较大,光补偿点(LCP)和暗呼吸速率(Rd)变化趋势不明显,P_(nmax)的变化范围为13.79~33.31μmol CO_2·m^(-2)·s^(-1),平均值为23.77μmol CO_2·m^(-2)·s^(-1),其中5月达到最大值,P_(nmax)季节变化显著;羧化速率(φ)、最大羧化速率(V_(cmax))、最大电子传递速率(J_(max))和光下暗呼吸(Rp)的季节动态变化也是呈现春季后期和初秋时期值比较高、在夏季波动较大的趋势,CO_2补偿点(Co)在整个生长季季节动态明显;CO_2饱和点(Cisat)的季节动态变化不明显;V_(cmax)在5月达到最大值(89.10μmol·m^(-2)·s^(-1)),在8月达到最小值(27.25μmol·m^(-2)·s^(-1)),平均值为56.29μmol·m^(-2)·s^(-1),J_(max)在9月达到最大值(78.86μmol CO_2·m^(-2)·s^(-1)),在8月达到最小值(24.19μmol CO_2·m^(-2)·s^(-1)),平均值为46.24μmol CO_2·m^(-2)·s^(-1),V_(cmax)和J_(max)季节变化显著;P_(nmax)、V_(cmax)、J_(max)和Rp与N_(mass)存在显著线性正相关,P_(nmax)、V_(cmax)和J_(max)与SLA存在显著线性正相关。本研究结果进一步证实,叶氮含量和比叶面积是影响油蒿光合能力的重要因素。研究获得的光合参数与叶性状的关系可为构建参数化生态系统过程模型提供帮助。
Understanding the seasonal dynamics of photosynthetic capacity of plants and its relationship with leaf traits is of great significance for accurate simulation of ecosystem carbon cycle. In this study, we measured in situ photosynthetic light and CO2 response curves of Artemisia ordosica over an entire growing season in the Mu Us Desert, and analyzed the relationship of leaf nitrogen content （Nmass）, specific leaf area （SLA） with the photosynthetic parameters of A. ordosica. As a result, the maximum net photosynthetic rate （Pnmax）, apparent quantum yield （α）, maximum carboxylation rate （Vcmax）, maximum electron transportation rate （Jmax） were relatively higher in the late spring and early autumn in the growing season, largely fluctuated in summer. Pnmax, α, Vcmax and Jmax ranged as 13.79-33.31 μmol CO2·m-2·s-1, 0.020-0.053 mol·mol-1, 27.25-89.10 μmol·m-2·s-1 and 24.19-62.18 μmol CO2·m-2·s-1, and averaged at 23.77 μmol CO2·m-2·s-1, 0.037 mol·mol-1, 56.29 μmol·m-2·s-1 and 42.44 μmol CO2·m-2·s-1 respectively. The light compensation point （LCP） and CO2 compensation point （Co） did not change significantly over the growing season. Correlation analysis showed that photosynthetic parameters Pnmax, Vcmax and Jmax were positively correlated with Nmass and SLA. The results further confirmed that the Nmass and SLA were important factors affecting the photosynthetic capacity of A. ordosica. The relationship between photosynthetic parameters and leaf traits obtained in this study can be used to help build parametric models of ecosystem processes.
出处
《生态学杂志》
CAS
CSCD
北大核心
2017年第4期916-924,共9页
Chinese Journal of Ecology
基金
国家自然科学基金项目(31270755、31670708和31670710)
中央高校基本科研业务费专项(2015ZCQ-SB-02)资助
关键词
油蒿
光合参数
叶氮含量
比叶面积
Artemisia ordosica
photosynthetic parameters
leaf nitrogen content
specific leafarea.
