Mevy Jean-Philippe, Biryol Charlotte, Boiteau-Barral Marine, Miglietta Franco
IMBE-UMR CNRS 7263/IRD 237, Aix-Marseille Université, 13331 Marseille, France.
Institute of Biometeorology, National Research Council (CNR-IBIMET), Via Caproni 8, 50145 Firenze, Italy.
Plants (Basel). 2022 Feb 12;11(4):505. doi: 10.3390/plants11040505.
Remote sensing techniques in terms of monitoring plants' responses to environmental constraints have gained much attention during recent decades. Among these constraints, climate change appears to be one of the major challenges in the Mediterranean region. In this study, the main goal was to determine how field spectrometry could improve remote sensing study of a Mediterranean shrubland submitted to climate aridification. We provided the spectral signature of three common plants of the Mediterranean garrigue: , and . The pattern of these spectra changed depending on the presence of a neighboring plant species and water availability. Indeed, the normalized water absorption reflectance (R975/R900) tended to decrease for each species in trispecific associations (11-26%). This clearly indicates that multispecific plant communities will better resist climate aridification compared to monospecific stands. While seemed to be more sensible to competition for water resources, exhibited a facilitation effect on in trispecific assemblage. Among the 17 vegetation indices tested, we found that the pigment pheophytinization index (NPQI) was a relevant parameter to characterize plant-plant coexistence. This work also showed that some vegetation indices known as indicators of water and pigment contents could also discriminate plant associations, namely RGR (Red Green Ratio), WI (Water Index), Red Edge Model, NDWI (Normalized Difference Water Index), and PRI (Photochemical Reflectance Index). The latter was shown to be linearly and negatively correlated to the ratio of R975/R900, an indicator of water status.
近几十年来，利用遥感技术监测植物对环境胁迫的响应备受关注。在地中海地区，这些胁迫因素中，气候变化似乎是主要挑战之一。本研究的主要目标是确定野外光谱测定法如何改进对遭受气候干旱化的地中海灌木丛的遥感研究。我们给出了地中海常绿矮灌木丛中三种常见植物的光谱特征：……、……和……。这些光谱的模式会根据相邻植物物种的存在和水分供应情况而变化。实际上，在三物种组合中，每种植物的归一化吸水反射率（R975/R900）都有下降趋势（11 - 26%）。这清楚地表明，与单物种林分相比，多物种植物群落能更好地抵御气候干旱化。虽然……似乎对水资源竞争更为敏感，但在三物种组合中，……对……表现出促进作用。在测试的17种植被指数中，我们发现色素脱镁叶绿素化指数（NPQI）是表征植物间共存的一个相关参数。这项研究还表明，一些已知的作为水分和色素含量指标的植被指数也能区分植物组合，即红 - 绿比（RGR）、水分指数（WI）、红边模型、归一化差异水分指数（NDWI）和光化学反射指数（PRI）。结果表明，后者与作为水分状况指标的R975/R900比值呈线性负相关。
