盐胁迫对大米草反射光谱和叶绿素浓度的影响

The Effect of Salinity Stresses on Chlorophyll Concentrations and Reflectance Spectra of Spartina Anglica

为促进海岸带生态系统的完整性和健康可持续发展,本文以滨海湿地盐沼植被大米草为研究对象,进行不同盐分浓度(10,20,30)胁迫处理,并对比分析不同盐分含量对各个测定期内的大米草叶片反射光谱和叶绿素浓度的影响。结果表明:大米草叶片叶绿素浓度在高盐胁迫下变化最显著,然后依次是中盐胁迫、低盐胁迫。大米草叶片反射光谱在不同的盐分胁迫下,曲线变化主要体现在绿光波段的反射峰和680nm附近的抬升程度;叶绿素浓度越低,抬升越明显。光谱特征参量D725/D702,D715/D702,D725/D722,BmSR,mSR,mND,NDI,DD的变化趋势与叶片叶绿素浓度演变趋势一致;胁迫程度不同,光谱特征参量的变化幅度也不同。该研究可为大田试验条件下探讨滨海湿地盐沼植被盐分胁迫反射光谱响应机理提供理论参考。

Leaf-level reflectance spectra and chlorophyll concentration for Spartina anglica in pots under three different salt concentrations （10, 20, 30） were tested and analyzed in order to improve the healthy and sustainable developments of coastal ecosystems. The research results indicated that chlorophyll concentration was subject to salinity stress and the impact order is high salinity stress〉middle salinity stress〉low salinity stress. Under the different salinity stresses, the reflectance spectra curve difference mainly focused on the reflectance at about 680 nm. And if the chlorophyll concentration was lower, the reflectance at about 680nm was higher. Spectral characteristics variables such as D725/D702, D715/D702, D725/D722, BmSR, mSR, raND, NDI, DD were testified that they can be used to reflect the changing trends of chlorophyll concentration in different measurement dates. In addition, Ihe changing trends for both spectral variables and chlorophyll concentration were the same. But the amplitudes of variation were the different because of salinity stresses. This research will provide important theoretical reference for discussing the effect mechanism of salinity stresses on salt marsh vegetation hyperspectral reflectance spectra in coastal wetland under field salinity stress test area.