Using digital repeat photography to model winter wheat phenology and photosynthetic CO2uptake

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 ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Repeat Photography ◽  
Digital Repeat Photography

scholarly journals Reviews and syntheses: Australian vegetation phenology: new insights from satellite remote sensing and digital repeat photography

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 ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Satellite Remote Sensing ◽  
Tropical Rainforests ◽  
Vegetation Phenology ◽  
Repeat Photography ◽  
Tropical Savannas ◽  
Diverse Range ◽  
Canopy Development ◽  
Continental Scale ◽  
Digital Repeat Photography

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/).

scholarly journals Correction: Luo, Y.P. et al., Using Near-Infrared Enabled Digital Repeat Photography to Track Structural and Physiological Phenology in Mediterranean Tree-Grass Ecosystems. Remote Sens. 2018, 10, 1293.

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

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

Monitoring Plant Phenology Using Digital Repeat Photography

2008 ◽  
Vol 41 (6) ◽  
pp. 949-958 ◽  
Author(s):  
Michael A. Crimmins ◽  
Theresa M. Crimmins
Keyword(s):  
Plant Phenology ◽  
Repeat Photography ◽  
Digital Repeat Photography

scholarly journals Mangrove Phenology and Water Influences Measured with Digital Repeat Photography

2021 ◽  
Vol 13 (2) ◽  
pp. 307
Author(s):  
Veeranun Songsom ◽  
Werapong Koedsin ◽  
Raymond J. Ritchie ◽  
Alfredo Huete
Keyword(s):  
Mangrove Forest ◽  
Water Levels ◽  
Water Dynamics ◽  
Andaman Sea ◽  
Seasonal Patterns ◽  
Mangrove Forests ◽  
Repeat Photography ◽  
Water Color ◽  
Tidal Water ◽  
Digital Repeat Photography

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.

Utilizing machine learning for detecting flowering in mid-range digital repeat photography

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

Vegetation phenology can be captured with digital repeat photography and linked to variability of root nutrition inHedysarum alpinum

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

scholarly journals Digital photography for assessing vegetation phenology in two contrasting northern ecosystems

2016 ◽  
Author(s):  
Maiju Linkosalmi ◽  
Mika Aurela ◽  
Juha-Pekka Tuovinen ◽  
Mikko Peltoniemi ◽  
Cemal M. Tanis ◽  
...  
Keyword(s):  
Digital Images ◽  
Time Windows ◽  
Coniferous Forest ◽  
Minor Effect ◽  
Forest Site ◽  
Vegetation Phenology ◽  
Repeat Photography ◽  
A Minor ◽  
Ecosystem Flux ◽  
Digital Repeat Photography

Abstract. Digital repeat photography has become a widely used tool for assessing the annual course of vegetation phenology of different ecosystems. A greenness measure derived from digital images potentially provides an inexpensive and powerful means to analyze the annual cycle of ecosystem phenology. By using the Green Chromatic Coordinate (GCC), we examined the feasibility of digital repeat photography for assessing the vegetation phenology in two contrasting high-latitude ecosystems. While the seasonal changes in GCC are more obvious for the ecosystem that is dominated by annual plants (open wetland), clear seasonal patterns were also observed for the evergreen ecosystem (coniferous forest). Limited solar radiation restricts the use of images during the night and in wintertime, for which time windows were determined based on images of a grey reference plate. The variability in cloudiness had only a minor effect on GCC, and GCC did not depend on the sun angle and direction either. The GCC of wetland developed in tandem with the daily photosynthetic capacity estimated from the atmosphere-ecosystem flux measurements. At the forest site, the seasonal GCC cycle correlated well with the flux data in 2015 but there were some temporary deviations in 2014. The year-to-year differences were most likely generated by meteorological conditions, especially the differences in temperature. In addition to depicting the seasonal course of ecosystem functioning, GCC was shown to respond to physiological changes on a daily time scale. It seems that our northern sites, with a short and pronounced growing season, suit especially well for the monitoring of phenological variations with digital images.

Sign in / Sign up

Export Citation Format

Share Document