Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes
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 influe...
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| Format: | Article |
| Language: | English |
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MDPI AG
2015-08-01
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| Series: | Remote Sensing |
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| Online Access: | http://www.mdpi.com/2072-4292/7/8/10832 |
| _version_ | 1828142870016557056 |
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| author | Jessica Walker Kirsten de Beurs Randolph H. Wynne |
| author_facet | Jessica Walker Kirsten de Beurs Randolph H. Wynne |
| author_sort | Jessica Walker |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-11T19:48:51Z |
| format | Article |
| id | doaj.art-12410fe8bb384cbcbf61aa5eabacba9f |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-04-11T19:48:51Z |
| publishDate | 2015-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-12410fe8bb384cbcbf61aa5eabacba9f2022-12-22T04:06:22ZengMDPI AGRemote Sensing2072-42922015-08-0178108321085510.3390/rs70810832rs70810832Phenological Response of an Arizona Dryland Forest to Short-Term Climatic ExtremesJessica Walker0Kirsten de Beurs1Randolph H. Wynne2Western Geographic Science Center, U.S. Geological Survey, 520 North Park Ave., Tucson, AZ 85719, USADepartment of Geography and Environmental Sustainability, The University of Oklahoma, 100 East Boyd St., Norman, OK 73019, USADepartment of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, 310 West Campus Dr., Blacksburg, VA 24061, USABaseline 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.http://www.mdpi.com/2072-4292/7/8/10832dryland forestsphenologySTARFMdata fusionLandsatMODIS |
| spellingShingle | Jessica Walker Kirsten de Beurs Randolph H. Wynne Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes Remote Sensing dryland forests phenology STARFM data fusion Landsat MODIS |
| title | Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes |
| title_full | Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes |
| title_fullStr | Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes |
| title_full_unstemmed | Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes |
| title_short | Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes |
| title_sort | phenological response of an arizona dryland forest to short term climatic extremes |
| topic | dryland forests phenology STARFM data fusion Landsat MODIS |
| url | http://www.mdpi.com/2072-4292/7/8/10832 |
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