Capturing functional trait response of dune plants using close-range remote sensing

Coastal dunes are dynamic ecosystems characterized by steep environmental gradients that impose significant stress on plant communities. These stressors, such as salinity, drought, and nutrient-poor soils, create a mosaic of plant adaptations and functional trait diversity. Traditional ecological studies have focused on plant traits to understand species' responses to environmental conditions, but a gap remains in connecting plant functional traits to large-scale ecological processes through remote sensing. By focusing on the key species Cakile maritima and a broader dune plant community, we explored how vegetation indices correlate with specific physiological and morphological traits, including specific leaf area (SLA), leaf dry matter content (LDMC), and flavonoid concentration.
This study presents a novel approach using close-range multispectral imaging to capture high-resolution (1.3 mm/px) data on plant functional traits in coastal dune ecosystems overcoming the limitations of broader-scale remote sensing methods which often suffer from lower spatial resolution and interference from non-vegetated areas. By manually selecting regions of interest (ROIs) for each species and filtering out background noise, we obtained precise multispectral signatures that accurately reflect the functional traits of individual plants and the entire community. Moreover, flavonoids explained a high percentage of the total variance of the multispectral indices.
The study demonstrates the effectiveness of close-range multispectral imaging in linking plant traits to ecological processes, with significant implications for upscaling plant responses to environmental variable across larger spatial scales. Furthermore, the research outlines practical guidelines for collecting and processing close-range multispectral data, offering a valuable new tool for monitoring ecosystems.

海岸沙丘是具有陡峭环境梯度特征的动态生态系统，这些梯度对植物群落施加了显著的压力。诸如盐分、干旱和养分贫瘠的土壤等压力因素，孕育了植物适应性和功能特征的多样性拼图。传统的生态学研究主要关注植物性状，以理解物种对环境条件的响应，但将植物功能性状与遥感技术在大规模生态过程中的联系仍存在空白。本研究聚焦于关键物种Cakile maritima和更广泛的沙丘植物群落，探究植被指数如何与特定的生理和形态性状相关联，包括比叶面积（SLA）、叶片干物质含量（LDMC）和黄酮类化合物浓度。本研究提出了一种新颖的方法，利用近距离多光谱成像技术捕捉高分辨率（1.3毫米/像素）的植物功能性状数据，克服了传统遥感方法在空间分辨率较低以及非植被区域干扰等方面的局限性。通过手动选择每个物种的兴趣区域（ROIs）并过滤背景噪声，我们获得了精确的多光谱特征，这些特征能够准确反映单个植物和整个群落的功能性状。此外，黄酮类化合物解释了多光谱指数总变异的高比例。该研究证明了近距离多光谱成像技术在将植物性状与生态过程相联系方面的有效性，对将植物对环境变量的响应扩展到更大空间尺度具有重要意义。此外，该研究概述了收集和处理近距离多光谱数据的实用指南，为生态系统监测提供了宝贵的工具。