Authors: Jane Southworth*, University of Florida, Sadie J Ryan, University of Florida, Reza Khatami, University of Florida, Peter Waylen, University of Florida, Hannah V Herrero, University of Florida, Erin Bunting, Michigan State University, Likai Zhu, University of Wisconsin, Michael Hill, University of North Dakota
Topics: Global Change, Remote Sensing
Keywords: time series remote sensing, NDVI, climate, biomes, land cover
Session Type: Paper
Start / End Time: 12:40 PM / 2:20 PM
Room: Grand Chenier, Sheraton, 5th Floor
Vegetation greenness, measured as NDVI utlizing a time-series based approach, gives us a useful signal to use across significant temporal extents and landscapes. In previous work, we illustrated the value of applying a time-series methods approach to what has, to date, been unquantifiable statistically, for global drylands systems. This study builds upon the methodology introduced in our global drylands work, to extend to all biomes and realms, globally, to explore the changing vegetation persistence and accumulation dynamics, and their potential shifts due to climatic and anthropogenic factors. We present a full 30 years of analysis, introducing a means of establishing significant trajectories and shifts. Overall we found positive vegetation persistence in the months June through November, and much more in the northern hemispheres over the southern. Forested geographic biomes tend to have positive persistence patterns overall. Dryland ecosystems were found to have overall decreases in vegetation persistence. Our work may help corroborate the global trends of greening linked mainly to carbon dioxide fertilization, especially related to the forested biomes. Highlights the importance though of land cover and both spatial and temporal variability in trends and patterns. In addition findings can be seen to link to changes in global precipitation patterns, especially as they link to seasonal shifts and timing. Such statistically rigorous and innovative approaches can be useful contributions to the study of vegetated systems globally, and sets the stage for more in-depth work.