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(tǒng)，具有調(diào)節(jié)氣候、保護(hù)生物多樣性等多種功能。然而，濕地生態(tài)系統(tǒng)極易受到自然和人為因素的影響，對(duì)其進(jìn)行有效監(jiān)測(cè)至關(guān)重要。

近年來(lái)，日光誘導(dǎo)葉綠素?zé)晒猓⊿IF）作為一種新興的遙感技術(shù)，為濕地監(jiān)測(cè)提供了新的視角。SIF在濕地監(jiān)測(cè)中具有多種應(yīng)用，主要包括以下幾個(gè)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(chǎn)力評(píng)估 / Assessment of Wetland Vegetation Productivity

SIF與植被的總初級(jí)生產(chǎn)力（GPP）具有很強(qiáng)的相關(guān)性。通過(guò)監(jiān)測(cè)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(cè)總初級(jí)生產(chǎn)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(tǒng)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(xiàng)研究對(duì)上海九端沙濕地自然保護(hù)區(qū)進(jìn)行了觀測(cè)和研究

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

觀測(cè)和模擬的 (a)冠層太陽(yáng)誘導(dǎo)葉綠素?zé)晒庠?60nm處的每日變化（SIF760）、(b)2019 年初級(jí)生產(chǎn)總生產(chǎn)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(tǒng)健康監(jiān)測(cè) / Monitoring Wetland Ecosystem Health

濕地生態(tài)系統(tǒng)對(duì)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(duì)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(yīng)能力。例如，干旱會(huì)導(dǎo)致植被光合效率下降，SIF信號(hào)也會(huì)相應(yīng)減弱。通過(guò)監(jiān)測(cè)SIF的變化，可以早期預(yù)警濕地生態(tài)系統(tǒng)的退化風(fēng)險(xiǎn)。

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(fù)評(píng)估與管理 / Evaluation and Management of Wetland Restoration

在濕地生態(tài)恢復(fù)過(guò)程中，SIF可以作為一種重要的評(píng)估工具。通過(guò)監(jiān)測(cè)恢復(fù)區(qū)域的SIF信號(hào)，可以快速評(píng)估植被的光合效能和覆蓋情況，了解恢復(fù)措施的效果。例如，在植被重建區(qū)域，SIF可以用于評(píng)估新種植植物的生長(zhǎng)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(dǎo)葉綠素?zé)晒猓⊿IF）監(jiān)測(cè)具有多個(gè)顯著特點(diǎn)：

它能夠直接反映光合作用，因?yàn)镾IF直接來(lái)源于葉綠素的光化學(xué)反應(yīng)，從而更準(zhǔn)確地表征植物的光合效率與碳吸收能力。與此同時(shí)，SIF對(duì)環(huán)境脅迫非常敏感，可早期響應(yīng)水分、溫度及養(yǎng)分等環(huán)境因素的變化，及時(shí)反映植被所受的脅迫狀態(tài)。此外，該監(jiān)測(cè)方法屬于非接觸式測(cè)量，不會(huì)對(duì)植被造成任何損傷，具有非破壞性的優(yōu)勢(shì)。在可擴(kuò)展性方面，SIF技術(shù)易于與遙感技術(shù)結(jié)合，支持大范圍、長(zhǎng)時(shí)間序列的連續(xù)監(jiān)測(cè)。

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(cè)任務(wù)可通過(guò)多種技術(shù)手段實(shí)現(xiàn)，包括葉片測(cè)量、塔基測(cè)量、航空遙感及衛(wèi)星遙感等；愛(ài)博能推出的日光誘導(dǎo)葉綠素?zé)晒獗O(jiān)測(cè)系統(tǒng)，就提供了在線式和無(wú)人機(jī)載系統(tǒng)，覆蓋從地面到低空的不同測(cè)量尺度。該系統(tǒng)適用于濕地生態(tài)監(jiān)測(cè)，其優(yōu)勢(shì)在于能夠高效、精準(zhǔn)地獲取大范圍濕地植被的生理狀態(tài)和脅迫響應(yīng)，幫助客戶(hù)實(shí)時(shí)掌握生態(tài)系統(tǒng)健康動(dòng)態(tài)，為濕地保護(hù)、恢復(fù)與管理提供關(guān)鍵的數(shù)據(jù)支撐和決策依據(jù)。

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(lái)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.