日光诱导叶绿素荧光，如何反映湿地生态健康？

How Does Sun-Induced Chlorophyll Fluorescence Reflect Wetland Ecosystem Health?

湿地作为地球上重要的生态系统，具有调节气候、保护生物多样性等多种功能。然而，湿地生态系统极易受到自然和人为因素的影响，对其进行有效监测至关重要。

近年来，日光诱导叶绿素荧光（SIF）作为一种新兴的遥感技术，为湿地监测提供了新的视角。SIF在湿地监测中具有多种应用，主要包括以下几个方面：

As a vital ecosystem on Earth, wetlands serve multiple functions such as climate regulation and biodiversity conservation. However, wetland ecosystems are highly susceptible to both natural and anthropogenic influences, making effective monitoring essential.

In recent years, Sun-Induced Chlorophyll Fluorescence (SIF) has emerged as a novel remote sensing technology that offers new perspectives for wetland monitoring. SIF has several key applications in this context, including the following:

1. 湿地植被生产力评估 / Assessment of Wetland Vegetation Productivity

SIF与植被的总初级生产力（GPP）具有很强的相关性。通过监测SIF，可以估算湿地植被的光合速率和碳汇能力。例如，在潮汐影响的滨海盐沼中，SIF可以用于监测总初级生产力和蒸散。最新研究显示，SIF有潜力成为量化沿海湿地生态系统中碳和水循环的一种新方法。

SIF is strongly correlated with Gross Primary Productivity (GPP) in vegetation. By monitoring SIF, it is possible to estimate photosynthetic rates and carbon sequestration capacity of wetland plants. For instance, in coastal salt marshes influenced by tides, SIF can be used to monitor GPP and evapotranspiration. Recent studies suggest that SIF has the potential to become a new method for quantifying carbon and water cycles in coastal wetland ecosystems.

一项研究对上海九端沙湿地自然保护区进行了观测和研究

A study conducted observations and research in the Shanghai Jiuduansha Wetland Nature Reserve

观测和模拟的 (a)冠层太阳诱导叶绿素荧光在760nm处的每日变化（SIF760）、(b)2019 年初级生产总生产率（GPP）和 (c)蒸散量（ET）

Monitoring and simulating the daily variations of (a) canopy sun-induced chlorophyll fluorescence at 760 nm (SIF760), (b) gross primary productivity (GPP), and (c) evapotranspiration (ET) for the year 2019.

2.湿地生态系统健康监测 / Monitoring Wetland Ecosystem Health

湿地生态系统对环境变化非常敏感，易受到干旱、污染、水位变化等因素的影响。SIF对这些环境胁迫具有高灵敏度，能够反映湿地植被的健康状况和适应能力。例如，干旱会导致植被光合效率下降，SIF信号也会相应减弱。通过监测SIF的变化，可以早期预警湿地生态系统的退化风险。

Wetland ecosystems are highly sensitive to environmental changes such as drought, pollution, and water level fluctuations. SIF is highly responsive to these environmental stresses and can reflect the health status and adaptability of wetland vegetation. For example, drought leads to reduced photosynthetic efficiency, which is accompanied by a decrease in SIF signals. Monitoring changes in SIF can provide early warnings of degradation risks in wetland ecosystems.

3.湿地恢复评估与管理 / Evaluation and Management of Wetland Restoration

在湿地生态恢复过程中，SIF可以作为一种重要的评估工具。通过监测恢复区域的SIF信号，可以快速评估植被的光合效能和覆盖情况，了解恢复措施的效果。例如，在植被重建区域，SIF可以用于评估新种植植物的生长状态和光合能力。

During ecological restoration of wetlands, SIF can serve as an important evaluation tool. By monitoring SIF signals in restored areas, it is possible to quickly assess vegetation photosynthetic performance and coverage, thereby evaluating the effectiveness of restoration measures. For instance, in revegetated zones, SIF can be used to monitor the growth status and photosynthetic capacity of newly planted vegetation.

日光诱导叶绿素荧光（SIF）监测具有多个显著特点：

它能够直接反映光合作用，因为SIF直接来源于叶绿素的光化学反应，从而更准确地表征植物的光合效率与碳吸收能力。与此同时，SIF对环境胁迫非常敏感，可早期响应水分、温度及养分等环境因素的变化，及时反映植被所受的胁迫状态。此外，该监测方法属于非接触式测量，不会对植被造成任何损伤，具有非破坏性的优势。在可扩展性方面，SIF技术易于与遥感技术结合，支持大范围、长时间序列的连续监测。

Sun-Induced Chlorophyll Fluorescence (SIF) monitoring exhibits several notable characteristics:

It directly reflects photosynthesis, as S originates from the photochemical reactions of chlorophyll, enabling more accurate characterization of plant photosynthetic efficiency and carbon uptake capacity. At the same time, SIF is highly sensitive to environmental stresses and can provide an early response to changes in factors such as water availability, temperature, and nutrient conditions, promptly reflecting the stress status of vegetation. Furthermore, this monitoring method is non-contact and non-destructive, causing no harm to plants. In terms of scalability, SIF technology can be easily integrated with remote sensing techniques, supporting large-scale and long-term continuous monitoring.

这些监测任务可通过多种技术手段实现，包括叶片测量、塔基测量、航空遥感及卫星遥感等；爱博能推出的日光诱导叶绿素荧光监测系统，就提供了在线式和无人机载系统，覆盖从地面到低空的不同测量尺度。该系统适用于湿地生态监测，其优势在于能够高效、精准地获取大范围湿地植被的生理状态和胁迫响应，帮助客户实时掌握生态系统健康动态，为湿地保护、恢复与管理提供关键的数据支撑和决策依据。

These monitoring tasks can be achieved through various technical means, including leaf-level measurements, tower-based platforms, aerial remote sensing, and satellite remote sensing.The Sun-Induced Chlorophyll Fluorescence Monitoring System launched by ExponentSci includes both online and UAV-borne systems, covering measurement scales from the ground to low-altitude airspace. This system is well-suited for wetland ecological monitoring due to its ability to efficiently and accurately capture the physiological status and stress responses of vegetation across large wetland areas. It enables clients to monitor ecosystem health dynamics in real time and provides critical data support and decision-making basis for wetland conservation, restoration, and management.

案例来源 / Source：

Lai, J., & Huang, Y. (2024). Potential of Solar-Induced Chlorophyll Fluorescence for Monitoring Gross Primary Productivity and Evapotranspiration in Tidally-Influenced Coastal Salt Marshes. Remote Sensing, 16(24), 4636.