Divergent Performances of Vegetation Indices in Extracting Photosynthetic Phenology for Northern Deciduous Broadleaf Forests

Yang, Yajie; Chen, Rui; Yin, Gaofei; Wang, Cong; Liu, Guoxiang; Verger, Aleixandre; Descals, Adrià; Filella, Iolanda; Peñuelas, Josep

doi:10.1109/lgrs.2022.3182405

Cited by 14 publications

(16 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the rate of change of photosynthetic phenology over time was 1.4-3.1 times greater than that of greenness phenology (Figure 2 and Supplementary Figure S1), which agreed with the results of existing work (Wang et al, 2019). The LUE model is available to explain the different performances in terms of EVI and SIF phenology (Walther et al, 2016;Yang et al, 2022). EVI is a robust proxy for fraction of absorbed photosynthetically active radiation (FAPAR) (Myneni and Williams, 1994) where not all photosynthetically active radiation (PAR) absorbed by the vegetation canopy is used for photosynthesis (Zhang et al, 2018c) but only light absorbed by chlorophyll is used for photosynthesis.…”

Section: Comparison Of Photosynthesis and Greenness Phenologysupporting

confidence: 88%

“…In addition, SOS CSIF (or SOS GOSIF ) was highly consistent with SOS EVI in terms of spatial trends (Figures 3, 5 and Supplementary Figures S2, S3), however, EOS CSIF (or EOS GOSIF ) was somewhat different from EOS EVI in terms of spatial trends (Figures 3, 5 and Supplementary Figures S2, S3), which was consistent with the available findings (Meng et al, 2021). The FAPAR by chlorophyll is the dominant factor in spring photosynthetic phenology, while the total amount of photosynthetically active radiation absorbed by chlorophyll is the dominant factor in autumn when radiation determines photosynthetic phenology (Yang et al, 2022). Besides, autumn photosynthetic phenology is controlled by photoperiod, even if the leaves remain green (Bauerle et al, 2012).…”

Section: Comparison Of Photosynthesis and Greenness Phenologysupporting

confidence: 85%

See 1 more Smart Citation

Vegetation greenness and photosynthetic phenology in response to climatic determinants

Dang

Shao

Huang

et al. 2023

Front. For. Glob. Change

View full text Add to dashboard Cite

Vegetation phenology is a key indicator of vegetation-climate interactions and carbon sink changes in ecosystems. Therefore, it is very important to understand the temporal and spatial variability of vegetation phenology and the driving climatic determinants [e.g., temperature (Ts) and soil moisture (SM)]. Vegetation greenness and photosynthetic phenology were derived using the double logistic (DL) method to enhance vegetation index (EVI) and solar-induced chlorophyll fluorescence (SIF) spring and autumn phenology, respectively. The growing season length (GSL) of greenness phenology (about 100 days) derived EVI was longer than GSL of photosynthetic phenology (about 80 days) derived SIF. Although their overall spatiotemporal pattern trends were consistent, photosynthetic phenology varied 1.4 to 3.1 times more than greenness phenology over time. In addition, SIF-based photosynthetic phenology and EVI-based greenness phenology showed consistent factors of drivers but differed to some extent in spatial patterns and the most relevant preseason dates. Spring photosynthetic phenology was mainly influenced by pre-season mean cumulative Ts (about 90 days). However, greenness phenology was controlled by both pre-seasons mean cumulative Ts [(about 55 days) and mean cumulative SM (about 40 days)]. Autumn photosynthetic phenology was controlled by both periods’ mean cumulative Ts [(about 20 days) and SM (about 20 days)], but autumn greenness phenology was mainly influenced by pre-season mean cumulative Ts (85 days). The comparison analysis of SIF and EVI phenology helps to understand the difference between photosynthetic phenology and greenness phenology at a regional scale.

show abstract

Section: Comparison Of Photosynthesis and Greenness Phenologysupporting

confidence: 88%

Section: Comparison Of Photosynthesis and Greenness Phenologysupporting

confidence: 85%

Vegetation greenness and photosynthetic phenology in response to climatic determinants

Dang

Shao

Huang

et al. 2023

Front. For. Glob. Change

View full text Add to dashboard Cite

show abstract

“…In contrast to information about green biomass proxied by EVI, SIF contains information on the absorbed photosynthetically active radiation by vegetation (APAR) and environmental stresses (especially water stress) related to photosynthetic light-use efficiency (LUE) [10]. Therefore, SIF is more sensitive to climate variability than EVI [39,40]. This is consistent with our finding that phenology from SIF was more correlated with climatic limitations than that from EVI, making it the main cause of the difference between phenology generated using SIF and EVI.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Vegetation Phenology Derived from Solar-Induced Chlorophyll Fluorescence and Enhanced Vegetation Index, and Their Relationship with Climatic Limitations

et al. 2022

Remote Sensing

Self Cite

View full text Add to dashboard Cite

Satellite-based vegetation datasets enable vegetation phenology detection at large scales, among which Solar-Induced Chlorophyll Fluorescence (SIF) and Enhanced Vegetation Index (EVI) are widely used proxies for detecting phenology from photosynthesis and greenness perspectives, respectively. Recent studies have revealed the divergent performances of SIF and EVI for estimating different phenology metrics, i.e., the start of season (SOS) and the end of season (EOS); however, the underlying mechanisms are unclear. In this study, we compared the SOS and EOS of natural ecosystems derived from SIF and EVI in China and explored the underlying mechanisms by investigating the relationships between the differences of phenology derived from SIF and EVI and climatic limiting factors (i.e., temperature, water and radiation). The results showed that the differences between phenology generated using SIF and EVI were diverse in space, which had a close relationship with climatic limitations. The increasing climatic limitation index could result in larger differences in phenology from SIF and EVI for each dominant climate-limited area. The phenology extracted using SIF was more correlated with climatic limiting factors than that using EVI, especially in water-limited areas, making it the main cause of the difference in phenology from SIF and EVI. These findings highlight the impact of climatic limitation on the differences of phenology from SIF and EVI and improve our understanding of land surface phenology from greenness and photosynthesis perspectives.

show abstract

“…We used NDVI in this study because it is a structural vegetation index that can be used as a proxy for leaf biomass (Yin et al., 2020). The decline in NDVI in autumn is linked to the loss of leaf biomass, while EVI and physiological indices, such as CCI, are linked to photosynthetic phenology and they depict earlier stages of leaf senescence that are linked to pigment degradation (Yang et al., 2022). Thus, the EoS estimated using low threshold values of NDVI is better indicated for detecting the timing of leaf shedding.…”

Section: Methodsmentioning

confidence: 99%

“…The seasonality of vegetation is commonly observed with time series of vegetation indices such as the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and the chlorophyl/carotenoid index (CCI) (Yang et al., 2022). Land surface phenology can be also studied using biophysical variables such as leaf area index or gross primary productivity.…”

Section: Introductionmentioning

confidence: 99%

Widespread drought‐induced leaf shedding and legacy effects on productivity in European deciduous forests

Descals

Verger

Yin

et al. 2022

Remote Sens Ecol Conserv

Self Cite

View full text Add to dashboard Cite

Heatwaves and droughts are becoming more common and severe in Europe, causing changes in tree phenology, disrupting the sequestration of carbon and causing tree mortality on a continental scale. The responses of leaf shedding to heatwaves and droughts remain uncertain, although temperate deciduous forests may shed their leaves if exposed to extreme heat and water stress. Little information, however, is available about the extent and recurrence of early leaf shedding induced by drought, likely because it occurs in small forest patches and can be discriminated only during a few weeks. We used highly spatiotemporal Sentinel-2 data as evidence of widespread drought-induced early leaf shedding in Europe during 2017-2021. We estimated the timing of leaf shedding from NDVI time series and a threshold-based method that extracts the end of the growing season. Then, we evaluated the heatwave and drought impacts at the end of season by analysing the z-score of Landsat-7 and -8 land surface temperature and the ERA5-Land air temperature and aridity index. The 10-m resolution Sentinel-2 data identified early leaf shedding not detected by the low-resolution (250 m) MODIS sensor. Early leaf shedding was observed across Europe during the entire study period and its occurrence was linked to preceding anomalously high temperatures and arid conditions. Our results also indicated that mean summer NDVI decreased significantly in the years following early leaf shedding, suggesting a legacy decline in vegetation productivity. Our study demonstrates that decametric satellite data can be used to monitor the responses of forests to extreme climate events at the canopy level and indicates that early leaf shedding associated with heatwaves and droughts is more widespread and frequent across the continent than previously thought.

show abstract

Divergent Performances of Vegetation Indices in Extracting Photosynthetic Phenology for Northern Deciduous Broadleaf Forests

Cited by 14 publications

References 27 publications

Vegetation greenness and photosynthetic phenology in response to climatic determinants

Vegetation greenness and photosynthetic phenology in response to climatic determinants

Comparison of Vegetation Phenology Derived from Solar-Induced Chlorophyll Fluorescence and Enhanced Vegetation Index, and Their Relationship with Climatic Limitations

Widespread drought‐induced leaf shedding and legacy effects on productivity in European deciduous forests

Contact Info

Product

Resources

About