Linking Spatial and Temporal Variation at Multiple Scales in a Heterogeneous Landscape∗

Abstract

Anthropogenic, ecological, and land-surface processes interact in landscapes at multiple spatial and temporal scales to create characteristic patterns. The relationships between temporally and spatially varying processes and patterns are poorly understood because of the lack of spatiotemporal observations of real landscapes over significant stretches of time. We report a new method for observing joint spatiotemporal landscape variation over large areas by analyzing multitemporal Landsat data. We calculate the spatiotemporal variation of the Normalized Difference Vegetation Index (NDVI) in the area covered by one Landsat scene footprint in north central Florida, over spatial windows of 10 4 -10 8 m 2 and time steps of two to sixteen years. The correlations, slopes, and intercepts of spatial versus temporal regressions in the real landscape all differ significantly from results obtained using a null model of a randomized landscape. Spatial variances calculated within windows of 10 5 -10 7 m 2 had the strongest relationships with temporal variances (regressions with both larger and smaller windows had lower coefficients of determination), and the relationships were stronger with longer time steps. Slopes and y-intercepts increased with window size and decreased with increased time step. The spatial and temporal scales at which NDVI signals are most strongly related may be the characteristic scales of the processes that most strongly determine landscape patterns. For example, the important time and space windows correspond with areas and timing of fires and tree plantation harvests. Observations of landscape dynamics will be most effective if conducted at the characteristic scales of the processes, and our approach may provide a tool for determining those scales. . His research interests include land cover change and sustainability, foraging dynamics and distributions of bats, and the ecology of African ticks.

Remote Sensing-Based Fractal Analysis and Scale Dependence Associated with Forest Fragmentation in an Amazon Tri‑National Frontier

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Forefronting the Socio-Ecological in Savanna Landscapes through Their Spatial and Temporal Contingencies

“…Patch dynamics are mapped via tracking the fluctuation of patch edges as patches change in shape, size, composition, and perimeter-to-area ratio. The need for these kinds of measurements in the study of disturbance ecology and nonequilibrial conditions [51,52] coincided with the development of different means to quantify landscape forms [53,54], to evaluate scale [55,56], and to create simplified landscapes as simulation models [38,57].…”

Modelaje integrado de cambio climático y socioeconómico en el manejo sostenible del recurso hídrico en la cuenca Arenal-Tempisque: Una propuesta multidisciplinaria

“…Para sintetizar los datos espaciales existentes pretendemos evaluar el cambio de cobertura y vincularlo con los modelos de interacción humana y el medio ambiente (Lele, Nagendra y Southworth, 2010;Stickler y Southworth, 2008;Daniels, Painter y Southworth, 2008), utilizando la teleobservación por satélite, una metodología que actualmente está bien validada (Cassidy, Binford, Southworth y Barnes, en prensa; Lele et al, 2010;Mondal y Southworth, 2009;Gibbes, Southworth y Keys, 2009;Southworth, Cumming, Marsik y Binford, 2006). Para el sitio de estudio en la cuenca del Tempisque múltiples imágenes en una variedad de escalas están disponibles para determinar cambios en la cobertura desde principios de 1980 hasta el presente; entre ellas: Quickbird, Ikonos y fotografías aéreas, Landsat MSS, TM, ETM y AS-TER e imágenes a gran escala AVHRR y MODIS.…”