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

濕地作為地球上重要的生態(tài)系統，具有調節(jié)氣候、保護生物多樣性等多種功能。然而，濕地生態(tài)系統極易受到自然和人為因素的影響，對其進行有效監(jiān)測至關重要。

近年來，日光誘導葉綠素熒光（SIF）作為一種新興的遙感技術，為濕地監(jiān)測提供了新的視角。SIF在濕地監(jiān)測中具有多種應用，主要包括以下幾個方面：

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. 濕地植被生產力評估 / Assessment of Wetland Vegetation Productivity

SIF與植被的總初級生產力（GPP）具有很強的相關性。通過監(jiān)測SIF，可以估算濕地植被的光合速率和碳匯能力。例如，在潮汐影響的濱海鹽沼中，SIF可以用于監(jiān)測總初級生產力和蒸散。最新研究顯示，SIF有潛力成為量化沿海濕地生態(tài)系統中碳和水循環(huán)的一種新方法。

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.

一項研究對上海九端沙濕地自然保護區(qū)進行了觀測和研究

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

觀測和模擬的 (a)冠層太陽誘導葉綠素熒光在760nm處的每日變化（SIF760）、(b)2019 年初級生產總生產率（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.濕地生態(tài)系統健康監(jiān)測 / Monitoring Wetland Ecosystem Health

濕地生態(tài)系統對環(huán)境變化非常敏感，易受到干旱、污染、水位變化等因素的影響。SIF對這些環(huán)境脅迫具有高靈敏度，能夠反映濕地植被的健康狀況和適應能力。例如，干旱會導致植被光合效率下降，SIF信號也會相應減弱。通過監(jiān)測SIF的變化，可以早期預警濕地生態(tài)系統的退化風險。

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.濕地恢復評估與管理 / Evaluation and Management of Wetland Restoration

在濕地生態(tài)恢復過程中，SIF可以作為一種重要的評估工具。通過監(jiān)測恢復區(qū)域的SIF信號，可以快速評估植被的光合效能和覆蓋情況，了解恢復措施的效果。例如，在植被重建區(qū)域，SIF可以用于評估新種植植物的生長狀態(tài)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.

日光誘導葉綠素熒光（SIF）監(jiān)測具有多個顯著特點：

它能夠直接反映光合作用，因為SIF直接來源于葉綠素的光化學反應，從而更準確地表征植物的光合效率與碳吸收能力。與此同時，SIF對環(huán)境脅迫非常敏感，可早期響應水分、溫度及養(yǎng)分等環(huán)境因素的變化，及時反映植被所受的脅迫狀態(tài)。此外，該監(jiān)測方法屬于非接觸式測量，不會對植被造成任何損傷，具有非破壞性的優(yōu)勢。在可擴展性方面，SIF技術易于與遙感技術結合，支持大范圍、長時間序列的連續(xù)監(jiān)測。

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.

這些監(jiān)測任務可通過多種技術手段實現，包括葉片測量、塔基測量、航空遙感及衛(wèi)星遙感等；愛博能推出的日光誘導葉綠素熒光監(jiān)測系統，就提供了在線式和無人機載系統，覆蓋從地面到低空的不同測量尺度。該系統適用于濕地生態(tài)監(jiān)測，其優(yōu)勢在于能夠高效、精準地獲取大范圍濕地植被的生理狀態(tài)和脅迫響應，幫助客戶實時掌握生態(tài)系統健康動態(tài)，為濕地保護、恢復與管理提供關鍵的數據支撐和決策依據。

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.

案例來源 / 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.