Monitoring Plant Phenology Using Digital Repeat Photography

2008 ◽  
Vol 41 (6) ◽  
pp. 949-958 ◽  
Author(s):  
Michael A. Crimmins ◽  
Theresa M. Crimmins
2016 ◽  
Vol 13 (17) ◽  
pp. 5085-5102 ◽  
Author(s):  
Caitlin E. Moore ◽  
Tim Brown ◽  
Trevor F. Keenan ◽  
Remko A. Duursma ◽  
Albert I. J. M. van Dijk ◽  
...  

Abstract. Phenology is the study of periodic biological occurrences and can provide important insights into the influence of climatic variability and change on ecosystems. Understanding Australia's vegetation phenology is a challenge due to its diverse range of ecosystems, from savannas and tropical rainforests to temperate eucalypt woodlands, semi-arid scrublands, and alpine grasslands. These ecosystems exhibit marked differences in seasonal patterns of canopy development and plant life-cycle events, much of which deviates from the predictable seasonal phenological pulse of temperate deciduous and boreal biomes. Many Australian ecosystems are subject to irregular events (i.e. drought, flooding, cyclones, and fire) that can alter ecosystem composition, structure, and functioning just as much as seasonal change. We show how satellite remote sensing and ground-based digital repeat photography (i.e. phenocams) can be used to improve understanding of phenology in Australian ecosystems. First, we examine temporal variation in phenology on the continental scale using the enhanced vegetation index (EVI), calculated from MODerate resolution Imaging Spectroradiometer (MODIS) data. Spatial gradients are revealed, ranging from regions with pronounced seasonality in canopy development (i.e. tropical savannas) to regions where seasonal variation is minimal (i.e. tropical rainforests) or high but irregular (i.e. arid ecosystems). Next, we use time series colour information extracted from phenocam imagery to illustrate a range of phenological signals in four contrasting Australian ecosystems. These include greening and senescing events in tropical savannas and temperate eucalypt understorey, as well as strong seasonal dynamics of individual trees in a seemingly static evergreen rainforest. We also demonstrate how phenology links with ecosystem gross primary productivity (from eddy covariance) and discuss why these processes are linked in some ecosystems but not others. We conclude that phenocams have the potential to greatly improve the current understanding of Australian ecosystems. To facilitate the sharing of this information, we have formed the Australian Phenocam Network (http://phenocam.org.au/).


2019 ◽  
Vol 11 (6) ◽  
pp. 726
Author(s):  
Yunpeng Luo ◽  
Tarek El-Madany ◽  
Gianluca Filippa ◽  
Xuanlong Ma ◽  
Bernhard Ahrens ◽  
...  

The authors modify the schematic plots in their article [...]


2015 ◽  
Vol 39 (4) ◽  
pp. 460-482 ◽  
Author(s):  
Jennifer M. Fitchett ◽  
Stefan W. Grab ◽  
Dave I. Thompson

Phenology, the timing of annually recurrent reproductive biological events, provides a critical signal of climate variability and change effects on plants. Considerable work over the past five decades has quantified the extent to which plant phenophases are responding to local changes in temperature and rainfall. Originally undertaken through the analysis of ground-based phenological observations, the discipline has more recently included phenophase indicators from satellite images and digital repeat photography. With research advances it has become evident that the responses of plant phenology to climate variability and change are both location- and species-specific. The extent to which plants are affected by changes in temperature and rainfall, their intrinsic adaptation capacity, will ultimately determine the potential for sustained ecological stability and food security. We review methodological approaches to plant phenological-climate change over time, analyse the regions and phenophases for which climate variability demonstrates a clear causal role, and finally reflect on the applications of phenological climate change investigations in broader biogeographical contexts.


2021 ◽  
Vol 13 (2) ◽  
pp. 307
Author(s):  
Veeranun Songsom ◽  
Werapong Koedsin ◽  
Raymond J. Ritchie ◽  
Alfredo Huete

The intertidal habitat of mangroves is very complex due to the dynamic roles of land and sea drivers. Knowledge of mangrove phenology can help in understanding mangrove growth cycles and their responses to climate and environmental changes. Studies of phenology based on digital repeat photography, or phenocams, have been successful in many terrestrial forests and other ecosystems, however few phenocam studies in mangrove forests showing the influence and interactions of water color and tidal water levels have been performed in sub-tropical and equatorial environments. In this study, we investigated the diurnal and seasonal patterns of an equatorial mangrove forest area at an Andaman Sea site in Phuket province, Southern Thailand, using two phenocams placed at different elevations and with different view orientations, which continuously monitored vegetation and water dynamics from July 2015 to August 2016. The aims of this study were to investigate fine-resolution, in situ mangrove forest phenology and assess the influence and interactions of water color and tidal water levels on the mangrove–water canopy signal. Diurnal and seasonal patterns of red, green, and blue chromatic coordinate (RCC, GCC, and BCC) indices were analyzed over various mangrove forest and water regions of interest (ROI). GCC signals from the water background were found to positively track diurnal water levels, while RCC signals were negatively related with tidal water levels, hence lower water levels yielded higher RCC values, reflecting brownish water colors and increased soil and mud exposure. At seasonal scales, the GCC profiles of the mangrove forest peaked in the dry season and were negatively related with the water level, however the inclusion of the water background signal dampened this relationship. We also detected a strong lunar tidal water periodicity in seasonal GCC values that was not only present in the water background, but was also detected in the mangrove–water canopy and mangrove forest phenology profiles. This suggests significant interactions between mangrove forests and their water backgrounds (color and depth), which may need to be accounted for in upscaling and coupling with satellite-based mangrove monitoring.


2021 ◽  
Vol 440 ◽  
pp. 109419
Author(s):  
Tae Kyung Kim ◽  
Sukyung Kim ◽  
Myoungsoo Won ◽  
Jong-Hwan Lim ◽  
Sukhee Yoon ◽  
...  

2012 ◽  
Vol 16 (2) ◽  
pp. 317-324 ◽  
Author(s):  
W. Nijland ◽  
N.C. Coops ◽  
S.C.P. Coogan ◽  
C.W. Bater ◽  
M.A. Wulder ◽  
...  

2012 ◽  
Vol 32 (16) ◽  
pp. 5146-5153 ◽  
Author(s):  
周磊 ZHOU Lei ◽  
何洪林 HE Honglin ◽  
孙晓敏 SUN Xiaomin ◽  
张黎 ZHANG Li ◽  
于贵瑞 YU Guirui ◽  
...  

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