{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T22:32:35Z","timestamp":1772922755620,"version":"3.50.1"},"reference-count":59,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2015,8,24]],"date-time":"2015-08-24T00:00:00Z","timestamp":1440374400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Baseline information about dryland forest phenology is necessary to accurately anticipate future ecosystem shifts. The overarching goal of our study was to investigate the variability of vegetation phenology across a dryland forest landscape in response to climate alterations. We analyzed the influence of site characteristics and climatic conditions on the phenological patterns of an Arizona, USA, ponderosa pine (Pinus ponderosa) forest during a five-year period (2005 to 2009) that encompassed extreme wet and dry precipitation regimes. We assembled 80 synthetic Landsat images by applying the spatial and temporal adaptive reflectance fusion method (STARFM) to 500 m MODIS and 30 m Landsat-5 Thematic Mapper (TM) data. We tested relationships between site characteristics and the timing of peak Normalized Difference Vegetation Index (NDVI) to assess the effect of climatic stress on the green-up of individual pixels during or after the summer monsoon. Our results show that drought-induced stress led to a fragmented phenological response that was highly dependent on microsite parameters, as both the spatial autocorrelation of peak timing and the number of significant site variables increased during the drought year. Pixels at lower elevations and with higher proportions of herbaceous vegetation were more likely to exhibit dynamic responses to changes in precipitation conditions. Our study demonstrates the complexity of responses within dryland forest ecosystems and highlights the need for standardized monitoring of phenology trends in these areas. The spatial and temporal variability of phenological signals may provide a quantitative solution to the problem of how to evaluate dryland land surface trends across time.<\/jats:p>","DOI":"10.3390\/rs70810832","type":"journal-article","created":{"date-parts":[[2015,8,25]],"date-time":"2015-08-25T02:34:23Z","timestamp":1440470063000},"page":"10832-10855","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Phenological Response of an Arizona Dryland Forest to  Short-Term Climatic Extremes"],"prefix":"10.3390","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3225-0317","authenticated-orcid":false,"given":"Jessica","family":"Walker","sequence":"first","affiliation":[{"name":"Western Geographic Science Center, U.S. Geological Survey, 520 North Park Ave., Tucson,  AZ 85719, USA"}]},{"given":"Kirsten","family":"De Beurs","sequence":"additional","affiliation":[{"name":"Department of Geography and Environmental Sustainability, The University of Oklahoma,  100 East Boyd St., Norman, OK 73019, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3649-835X","authenticated-orcid":false,"given":"Randolph","family":"Wynne","sequence":"additional","affiliation":[{"name":"Department of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, 310 West Campus Dr., Blacksburg, VA 24061, USA"}]}],"member":"1968","published-online":{"date-parts":[[2015,8,24]]},"reference":[{"key":"ref_1","unstructured":"Hassan, R.M., Scholes, R., and Ash, N. (2005). Ecosystems and Human Well-Being: Current State and Trends (The Millennium Ecosystem Assessment Series), Island Press."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"15","DOI":"10.5751\/ES-02169-120215","article-title":"Defining old growth for fire-adapted forests of the western United States","volume":"12","author":"Kaufmann","year":"2007","journal-title":"Ecol. Soc."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1201","DOI":"10.1890\/1051-0761(1997)007[1201:OIHISR]2.0.CO;2","article-title":"Overstory-imposed heterogeneity in solar radiation and soil moisture in a semiarid woodland","volume":"7","author":"Breshears","year":"1997","journal-title":"Ecol. Appl."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1490","DOI":"10.1016\/j.jaridenv.2008.02.012","article-title":"Impacts and uncertainties of upscaling of remote-sensing data validation for a semi-arid woodland","volume":"72","author":"Hufkens","year":"2008","journal-title":"J. Arid Environ."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"14839","DOI":"10.1073\/pnas.95.25.14839","article-title":"Drought-induced shift of a forest-woodland ecotone: Rapid landscape response to climate variation","volume":"95","author":"Allen","year":"1998","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1038\/35041641","article-title":"Helping western forests heal","volume":"408","author":"Covington","year":"2000","journal-title":"Nature"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"21289","DOI":"10.1073\/pnas.0914211107","article-title":"Forest responses to increasing aridity and warmth in the southwestern United States","volume":"107","author":"Williams","year":"2010","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"940","DOI":"10.1126\/science.1128834","article-title":"Warming and earlier spring increase western U.S. forest wildfire activity","volume":"313","author":"Westerling","year":"2006","journal-title":"Science"},{"key":"ref_9","unstructured":"Krist, F.J., Ellenwood, J.R., Woods, M.E., McMahan, A.J., Cowardin, J.P., Ryerson, D.E., Sapio, F.J., Zweifler, M.O., and Romero, S.A. (2014). 2013\u20132027 National Insect and Disease Forest Risk Assessment, Forest Health Technology Enterprise Team, United States Department of Agriculture, Forest Service."},{"key":"ref_10","unstructured":"Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., and Miller, H.I. (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press."},{"key":"ref_11","unstructured":"Stocker, T.F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P.M. (2013). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7063","DOI":"10.1073\/pnas.0901438106","article-title":"Temperature sensitivity of drought-induced tree mortality portends increased regional die-off under global-change-type drought","volume":"106","author":"Adams","year":"2009","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"15144","DOI":"10.1073\/pnas.0505734102","article-title":"Regional vegetation die-off in response to global-change-type drought","volume":"102","author":"Breshears","year":"2005","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2387","DOI":"10.1890\/06-1951.1","article-title":"Spatial patterns of forest characteristics in the Western United States derived from inventories","volume":"17","author":"Hicke","year":"2007","journal-title":"Ecol. Appl."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Lieth, H. (1974). Phenology and Seasonality Modelling, Springer.","DOI":"10.1007\/978-3-642-51863-8"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1007\/s004840000054","article-title":"Trends in phenological phases in Europe between 1951 and 1996","volume":"44","author":"Menzel","year":"2000","journal-title":"Int. J. Biomet."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1111\/j.1365-2486.2005.01097.x","article-title":"Onset of spring starting earlier across the Northern Hemisphere","volume":"12","author":"Schwartz","year":"2006","journal-title":"Global Chang. Biol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1016\/j.tree.2007.04.003","article-title":"Shifting plant phenology in response to global change","volume":"22","author":"Cleland","year":"2007","journal-title":"Trends Ecol. Evol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Schwartz, M.D. (2003). Phenology: An Integrative Environmental Science, Kluwer Academic Publishers.","DOI":"10.1007\/978-94-007-0632-3"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"887","DOI":"10.1126\/science.1173004","article-title":"Phenology feedbacks on climate change","volume":"324","author":"Rutishauser","year":"2009","journal-title":"Science"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1461","DOI":"10.1126\/science.1186473","article-title":"Phenology under global warming","volume":"327","author":"Basler","year":"2010","journal-title":"Science"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"9729","DOI":"10.1073\/pnas.94.18.9729","article-title":"Reorganization of an arid ecosystem in response to recent climate change","volume":"94","author":"Brown","year":"1997","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1007\/s00442-004-1570-y","article-title":"A multi-scale perspective of water pulses in dryland ecosystems: Climatology and ecohydrology of the western USA","volume":"141","author":"Loik","year":"2004","journal-title":"Oecologia"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1890\/1051-0761(2003)013[0629:DICACI]2.0.CO;2","article-title":"Desertification in central Argentina: Changes in ecosystem carbon and nitrogen from imaging spectroscopy","volume":"13","author":"Asner","year":"2003","journal-title":"Ecol. Appl."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2335","DOI":"10.1111\/j.1365-2486.2009.01910.x","article-title":"Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982\u20132006","volume":"15","author":"White","year":"2009","journal-title":"Global Chang. Biol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1353","DOI":"10.1016\/j.foreco.2008.12.002","article-title":"Bark beetle-caused mortality in a drought-affected ponderosa pine landscape in Arizstona, USA","volume":"257","author":"McMillin","year":"2009","journal-title":"For. Ecol. Manag."},{"key":"ref_27","unstructured":"Graham, R.T., and Jain, T.B. (2005). Proceedings of the Symposium on Ponderosa Pine: Issues, Trends, and Management, Pacific Southwest Research Station, U.S. Department of Agriculture, Forest Service. Gen. Tech. Rep PSW-GTR-198."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1007\/s00442-004-1585-4","article-title":"Drought responses of conifers in ecotone forests of northern Arizona: Tree ring growth and leaf \u03b413C","volume":"140","author":"Adams","year":"2004","journal-title":"Oecologia"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"3021","DOI":"10.1139\/X08-142","article-title":"Western juniper and ponderosa pine ecotonal climate-growth relationship across landscape gradients in southern Oregon","volume":"38","author":"Knutson","year":"2008","journal-title":"Can. J. For. Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/j.foreco.2006.09.003","article-title":"Changes in understory vegetation of a ponderosa pine forest in northern Arizona 30 years after a wildfire","volume":"235","author":"Bataineh","year":"2006","journal-title":"For. Ecol. Manag."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1007\/s11258-007-9367-9","article-title":"Restoring plant species diversity and community composition in a ponderosa pine-bunchgrass ecosystem","volume":"197","author":"Laughlin","year":"2007","journal-title":"Plant Ecol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"342","DOI":"10.1890\/06-2137.1","article-title":"Phenology of mixed woody-herbaceous ecosystems following extreme events: Net and differential responses","volume":"89","author":"Rich","year":"2008","journal-title":"Ecology"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2207","DOI":"10.1109\/TGRS.2006.872081","article-title":"On the blending of the Landsat and MODIS surface reflectance: Predicting daily Landsat surface reflectance","volume":"44","author":"Gao","year":"2006","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1016\/j.rse.2011.10.014","article-title":"Evaluation of Landsat and MODIS data fusion products for analysis of dryland forest phenology","volume":"117","author":"Walker","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.rse.2014.01.007","article-title":"Dryland vegetation phenology across an elevation gradient in Arizona, USA, investigated with fused MODIS and Landsat data","volume":"144","author":"Walker","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/j.rse.2003.11.006","article-title":"Land surface phenology, climatic variation, and institutional change: Analyzing agricultural land cover change in Kazakhstan","volume":"89","author":"Henebry","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1890\/070217","article-title":"Tracking the rhythm of the season in the face of global change: phenological research in the 21st century","volume":"7","author":"Morisette","year":"2009","journal-title":"Front. Ecol. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.1016\/j.rse.2010.04.005","article-title":"Land surface phenology from MODIS: Characterization of the Collection 5 global land cover dynamics product","volume":"114","author":"Ganguly","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Schwartz, M.D. (2013). Phenology: An Integrative Environmental Science, Springer.","DOI":"10.1007\/978-94-007-6925-0"},{"key":"ref_40","unstructured":"Staudenmaier, M., Preston, R., and Sorenson, P. (2009). Climate of Flagstaff, Arizona, NOAA Technical Document NWS WR-273; National Technical Information Service."},{"key":"ref_41","unstructured":"National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center (NCDC) Climatological Rankings, 2005\u20132009, Available online: http:\/\/www.ncdc.noaa.gov\/temp-and-precip\/climatological-rankings\/."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.rse.2006.11.008","article-title":"Mapping moderate-scale land-cover over very large geographic areas within a collaborative framework: A case study of the Southwest Regional Gap Analysis Project (SWReGAP)","volume":"108","author":"Lowry","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_43","unstructured":"USGS National Gap Analysis Program. Available online: http:\/\/earth.gis.usu.edu\/swgap\/data\/atool\/files\/swgap_legend_desc.pdf."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"8763","DOI":"10.1029\/98JD00089","article-title":"Expected retrieval accuracies of bidirectional reflectance and albedo from EOS-MODIS and MISR angular sampling","volume":"103","author":"Lucht","year":"1998","journal-title":"J. Geophys. Res.-Atmos."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1109\/36.841980","article-title":"An algorithm for the retrieval of albedo from space using semiempirical BRDF models","volume":"38","author":"Lucht","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/S0034-4257(02)00091-3","article-title":"First operational BRDF, albedo nadir reflectance products from MODIS","volume":"83","author":"Schaaf","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2061","DOI":"10.1080\/01431160802549237","article-title":"Sensitivity of vegetation phenology detection to the temporal resolution of satellite data","volume":"30","author":"Zhang","year":"2009","journal-title":"Int. J. Remote Sens."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1109\/LGRS.2005.857030","article-title":"A Landsat surface reflectance dataset for North America, 1990\u20132000","volume":"3","author":"Masek","year":"2006","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_49","first-page":"1369","article-title":"A comparison of satellite sensor bands for vegetation monitoring","volume":"44","author":"Tucker","year":"1978","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_50","unstructured":"Hudson, I.L., and Keatley, M.R. (2010). Phenology of Ecosystem Processes: Applications in Global Change Research, Springer."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"603","DOI":"10.1111\/j.1654-1103.2002.tb02087.x","article-title":"Equations for potential annual direct incident radiation and heat load","volume":"13","author":"McCune","year":"2002","journal-title":"J. Veg. Sci."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1111\/j.2517-6161.1948.tb00012.x","article-title":"The interpretation of statistical maps","volume":"10","author":"Moran","year":"1948","journal-title":"J. R. Stat. Soc. B"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/j.rse.2004.12.021","article-title":"Geostatistical and local cluster analysis of high resolution hyperspectral imagery for detection of anomalies","volume":"95","author":"Goovaerts","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1198\/0003130043277","article-title":"Bootstrap methods for developing predictive models","volume":"58","author":"Austin","year":"2004","journal-title":"Am. Stat."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1111\/j.1654-1103.2009.01118.x","article-title":"Functional differences between summer and winter season rain assessed with MODIS-derived phenology in a semi-arid region","volume":"21","author":"Jenerette","year":"2010","journal-title":"J. Veg. Sci."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1007\/s10584-005-5922-3","article-title":"Reconstructed temperature and precipitation on a millennial timescale from tree-rings in the southern Colorado Plateau, USA","volume":"70","author":"Salzer","year":"2005","journal-title":"Clim. Chang."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1983","DOI":"10.1111\/j.2007.0030-1299.16034.x","article-title":"Drought induces lagged tree mortality in a subalpine forest in the Rocky Mountains","volume":"116","author":"Bigler","year":"2007","journal-title":"Oikos"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1111\/j.1466-8238.2010.00571.x","article-title":"Remotely sensed vegetation phenology and productivity along a climatic gradient: On the value of incorporating the dimension of woody plant cover","volume":"20","author":"Davison","year":"2011","journal-title":"Global Ecol. Biogeogr."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1220","DOI":"10.1016\/j.rse.2011.01.005","article-title":"Land surface phenology of North American mountain environments using moderate resolution imaging spectroradiometer data","volume":"115","year":"2011","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/8\/10832\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:47:16Z","timestamp":1760215636000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/8\/10832"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,8,24]]},"references-count":59,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2015,8]]}},"alternative-id":["rs70810832"],"URL":"https:\/\/doi.org\/10.3390\/rs70810832","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,8,24]]}}}