Plant phenology has gained new importance in the context of global change research, stimulating the development of novel technologies for phenological observations. Regular digital cameras have been effectively used as three-channel imaging sensors, providing measures of leaf color change or phenological shifts in plants. We monitored a species rich Brazilian cerrado savanna to assess the reliability of digital images to detect leaf-changing patterns. Analysis was conducted by extracting color information from selected parts of the image named regions of interest (ROIs). We aimed to answer the following questions: (i) Do digital cameras capture leaf changes in cerrado savanna vegetation? (ii) Can we detect differences in phenological changes among species crowns and the cerrado community? (iii) Is the greening pattern detected for each species by digital camera validated by our on-the-ground leafing phenology (direct observation of tree leaf changes)? We analyzed daily sequences of five images per hour, taken from 6:00 to 18:00. h, recorded during the cerrado main leaf flushing season. We defined 24 ROIs in the original digital image, including total or partial regions and crowns of six plant species. Our results indicated that: (i) for the studied period, single plant species ROIs were more sensitive to changes in relative green values than the community ROIs, (ii) three leaf strategies could be depicted from the species' ROI patterns of green color change, and (iii) the greening patterns and leaf functional groups were validated by our on-the-ground phenology. We concluded that digital cameras are reliable tools to monitor high diverse tropical seasonal vegetation and it is sensitive to inter-species differences of leafing patterns. © 2014 Elsevier B.V.19 6270Ahl, D.E., Gower, S.T., Burrows, S.N., Shabanov, N.V., Myneni, R.B., Knyazikhin, Y., Monitoring spring canopy phenology of a deciduous broadleaf forest using MODIS (2006) Remote Sens. Environ., 104, pp. 88-95Ahrends, H., Bruegger, R., Stoeckli, R., Schenk, J., Michna, P., Jeanneret, F., Wanner, H., Eugster, W., Quantitative phenological observations of a mixed beech forest in northern Switzerland with digital photography (2008) J. Geophys. Res., 116, pp. 1-11Ahrends, H., Etzold, S., Kutsch, W., Stoeckli, R., Bruegger, R., Jeanneret, F., Wanner, H., Eugster, W., Tree phenology and carbon dioxide fluxes: use of digital photography at for process-based interpretation the ecosystem scale (2009) Clim. Res., 39, pp. 261-274Almeida, J., dos Santos, J.A., Alberton, B., da S.Torres, R., Morellato, L.P.C., Remote phenology: applying machine learning to detect phenological patterns in a cerrado savanna (2014) Ecol. Inform., , (in press)Billow, C., Matson, P., Yoder, B., Seasonal biochemical changes in coniferous forest canopies and their response to fertilization (1994) Tree Physiol., 14, pp. 563-574Camargo, M.G.G., Souza, R.M., Reys, P., Morellato, L.P.C., Effects of environmental conditions associated to the cardinal orientation on the reproductive phenology of the cerrado savanna tree Xylopia aromatica (Annonaceae) (2011) An. Acad. Bras. Cienc., 83, pp. 1007-1019Camargo, M.G.G., Cazetta, E., Schaefer, M., Morellato, L.P.C., Fruit color and contrast in seasonal habitats - a case study from a cerrado savanna (2013) Oikos, 122, pp. 1335-1342Chambers, J.Q., Asner, G.P., Morton, D.C., Anderson, L.O., Saatch, S.S., Espirito-Santo, F.D.B., Palace, M., Souza, C., Regional ecosystem structure and function: ecological insights from remote sensing of tropical forests (2007) Trends Ecol. Evol., 22, pp. 414-423Coutinho, L.M., O conceito de Cerrado (1978) Rev. bras. Bot., 1, pp. 17-23Crimmins, M.A., Crimmins, T.M., Monitoring plant phenology using digital repeat photography (2008) Environ. Manage., 41, pp. 949-958Gholz, H.L., Fitz, F.K., Waring, R.H., Leaf area differences associated with old-growth forest communities in the western Oregon Cascades (1976) Can. J. For. Res., 6, pp. 49-57Gillespie, A.R., Kahle, A.B., Walker, R.E., Color enhancement of highly correlated images. 2. Channel ratio and chromaticity transformation techniques (1987) Remote Sens. Environ., 22, pp. 343-365Graham, E.A., Yuen, E.M., Robertson, G.F., Kaiser, W.J., Hamilton, M.P., Rundel, P.W., Budburst and leaf area expansion measured with a novel mobile camera system and simple color thresholding (2009) Environ. Exp. Bot., 65, pp. 238-244Graham, E.A., Riordan, E.C., Yuen, E.M., Estrin, D., Rundel, P.W., Public internet-connected cameras used as a cross-continental ground-based plant phenology monitoring system (2010) Glob. Chang. Biol., 16, pp. 3014-3023Henneken, R., Dose, V., Schleip, C., Menzel, A., Detecting plant seasonality from webcams using Bayesian multiple change point analysis (2013) Agric. For. Meteorol., 168, pp. 177-185Ide, R., Oguma, H., Use of digital cameras for phenological observations (2010) Ecol. Inform., 5, pp. 339-347Keeling, C.D., Chin, J.F.S., Whorf, T.P., Increased activity of northern vegetation inferred from atmospheric CO2 measurements (1996) Nature, 382, pp. 146-149Köppen, W., (1931) Grundriss der Klimakunde, , Gruyter, BerlinKurc, S., Benton, L., Digital image-derived greenness links deep soil moisture to carbon uptake in a creosotebush-dominated shrubland (2010) J. Arid Environ., 4, pp. 585-594Lenza, E., Klink, C.A., Comportamento fenológico de espécies lenhosas em um cerrado sentido restrito de Brasília, DF (2006) Rev. bras. Bot., 29, pp. 627-638Loustau, D., Bosc, A., Colin, A., Davi, H., Francois, C., Dufrene, E., Eque, M., Delage, J., Modelling the climate change effects on the potential reduction of French plains forests at the sub regional level (2005) Tree Physiol., 25, pp. 813-823Merzlyak, M.N., Gitelson, A.A., Chivkunova, O.B., Rakitin, V.Y.U., Non-destructive optical detection of pigment changes during leaf senescence and fruit ripening (1999) Physiol. Plant., 106, pp. 135-141Migliavacca, M., Galvano, M., Cremonese, E., Rossini, M., Meroni, M., Sonnentag, O., Cogliati, S., Richardson, A.D., Using digital repeat digital photography and eddy covariance data to model grassland phenology and photosynthetic CO2 uptake (2011) Agric. For. Meteorol., 151, pp. 1325-1337Monasterio, M., Sarmiento, G., Phenological strategies of plant species in the tropical and semideciduous forest of the Venezuelan Llanos (1976) J. Biogeogr., 36, pp. 325-355Morellato, L.P.C., Rodrigues, R.R., Leitão filho, H.F., Joly, C.A., Estudo comparativo da fenologia de espécies arbóreas de floresta de altitude e floresta mesófila semi-decídua na Serra do Japí, Jundiaí, São Paulo (1989) Rev. bras. Bot., 12, pp. 85-98Morellato, L.P.C., Talora, D.C., Takahasi, A., Bencke, C.C., Romera, E.C., Zipparro, V.B., Phenology of Atlantic rain forest trees: a comparative study (2000) Biotropica, 32, pp. 811-823Morellato, L.P.C., Camargo, M.G.G., D'Eça Neves, F.F., Luize, B.G., Msantovani, A., Hudson, I., The Influence of Sampling Method, Sample Size, and Frequency of Observations on Plant Phenological Patterns and Interpretation in Tropical Forest Trees (2010) Phenological research, pp. 99-121. , Springer, Netherlands, I.L. Hudson, M.R. Keatley (Eds.)Morellato, L.P.C., Alberti, L.F., Hudson, I.L., Applications of Circular Statistics in Plant Phenology: A Case Studies Approach (2010) Phenological research, pp. 339-359. , Springer, Netherlands, I.L. Hudson, M.R. Keatley (Eds.)Morellato, L.P.C., Gressler, E., Camargo, M.G.G., A review of plant phenology in South and Central America (2013) Phenology: An Integrative Environmental Science, pp. 91-113. , Springer, New York, M.D. Schwartz (Ed.)Morisette, J.T., Richardson, A.D., Knapp, A.K., Fisher, J.I., Graham, E.A., Abatzoglou, J., Wilson, B.E., Liang, L., Tracking the rhythm of the seasons in the face of global change: phenological research in the 21st century (2009) Front. Ecol. Environ., 7, pp. 253-260Nagai, S., Maeda, T., Gamo, M., Muraoka, H., Suzuki, R., Nasahara, K.N., Using digital camera images to detect canopy condition of deciduous broad-leaved trees (2011) Plant Ecol. Divers., 4, pp. 79-89Negi, G.C.S., Leaf and bud demography and shoot growth in evergreen and deciduous trees of central Himalaya, India (2006) Trees, 20, pp. 416-429Parmesan, C., Yohe, G., A globally coherent fingerprint of climate change impacts across natural systems (2003) Nature, 421, pp. 37-42Peñuelas, J., Boada, M., A global change-induced biome shift in the Montseny mountains (NE Spain) (2003) Glob. Chang. Biol., 9, pp. 131-140Petchey, O.L., Gaston, K.J., Functional diversity (FD), species richness and community composition (2002) Ecol. Lett., 5, pp. 402-411Polgar, C.A., Primack, R.B., Leaf-out phenology of temperate woody plants: from trees to ecosystems (2011) New Phytol., 191, pp. 926-941Reich, P.B., Phenology of tropical forests: patterns, causes and consequences (1995) Can. J. Bot., 73, pp. 164-174Reich, P.B., Walters, M.B., Ellsworth, D.S., From tropics to tundra: global convergence in plant functioning (1997) Proc. Natl. Acad. Sci. U. S. A., 94, pp. 13730-13734Richardson, A.D., Jenkins, J.P., Braswell, B.H., Hollinger, D.Y., Ollinger, S.V., Smith, M.L., Use of digital webcam images to track spring green-up in a deciduous broadleaf forest (2007) Oecologia, 152, pp. 323-334Richardson, A.D., Braswell, B.H., Hollinger, D.Y., Jenkins, J.P., Ollinger, S.V., Near-surface remote sensing of spatial and temporal variation in canopy phenology (2009) Ecol. Appl., 19, pp. 1417-1428Rosenzweig, C., Karoly, D., VicarellI, M., Neofotis, P., Wu, Q., Casassa, G., Menzel, A., Imeson, A., Attributing physical and biological impacts to anthropogenic climate change (2008) Nature, 453, pp. 353-357Rotzer, T., Grote, R., Pretzsch, H., The timing of bud burst and its effect on tree growth (2004) Int. J. Biometeorol., 48, pp. 109-118Rubim, P., Nascimento, H.E.M., Morellato, L.P.C., Variações interanuais na fenologia de uma comunidade arbórea de floresta semidecídua no sudeste do Brasil (2010) Acta bot. Bras., 24, pp. 756-764Schwartz, M.D., Reed, B.C., White, M.A., Assessing satellite derived start-of-season measures in the conterminous USA (2002) Int. J. Climatol., 22, pp. 1793-1805Shaver, G.R., Mineral nutrition and leaf longevity in an evergreen shrub, Ledum palustre ssp. Decumbens (1981) Oecologia, 49, pp. 362-365Slaughter, D.C., Giles, D.K., Downey, D., Autonomous robotic weed control systems: a review (2008) Comput. Electron. Agric., 61, pp. 63-78Sonnentag, O., Hufkens, K., Teshera-Sterne, C., Young, A.M., Friedl, M., Braswell, B.H., Digital repeat photography for phenological research in forest ecosystems (2012) Agric. For. Meteorol., 152, pp. 157-177Van Ommen Kloeke, A.E.E., Douma, J.C., Ordonez, J.C., Reick, P.B., Van Bodegon, P.M., Global quantification of contrasting leaf life span strategies for deciduous and evergreen species in response to environmental conditions (2012) Glob. Ecol. Biogeogr., 21, pp. 224-235Walther, G.R., Plants in a warmer world (2004) Perspect. Plant Ecol., 6, pp. 169-185Walther, G.R., Post, E., Convey, P., Menzel, A., Parmesan, C., Beebee, T.J.C., Fromentin, J.M., Bairlein, F., Ecological responses to recent climate change (2002) Nature, 416, pp. 389-395Wang, Q., Tenhunen, J., Dinh, N.Q., Reichstein, M., Vesala, T., Keronen, P., Similarities in round- and satellite-based NDVI time series and their relationship to physiological activity of a Scots pine forest in Finland (2004) Remote Sens. Environ., 93, pp. 225-237White, M.A., Running, S.W., Thornton, P.E., The impact of growing-season length variability on carbon assimilation and evapotranspiration over 88years in the eastern US deciduous forest (1999) Int. J. Biometeorol., 42, pp. 139-145Woebbecke, D.M., Meyer, G.E., Vonbargen, K., Mortensen, D.A., Color indexes for weed identification under various soil, residue, and lighting conditions (1995) Trans. ASAE, 38, pp. 259-269Zhang, Q., Xiao, X., Braswell, B., Linder, E., Ollinger, S., Smith, M.L., Characterization of seasonal variation of forest canopy in a temperate deciduous broadleaf forest, using daily MODIS data (2006) Remote Sens. Environ., 105, pp. 189-203Zhao, J., Zhang, Y., Tan, Z., Song, Q., Liang, N., Yu, L., Zhao, J., Using digital cameras for comparative phenological monitoring in an evergreen broad-leaved forest and a seasonal rain forest (2012) Ecol. Inform., 10, pp. 65-72