RECENT COMPARISON OF TRENDS IN FLORIDIAN AND TEXAN MANGROVES WITH NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)

Mangroves are coastal forests that provide a variety of ecosystem services, particularly as protectors that shelter the surrounding communities from natural disturbances such as storms. In this study, NDVI (normalized difference vegetation index) was used to compare the vegetation conditions of Floridian and Texan mangroves over the last decade. The data indicated that the NDVI over the Floridian study area had no significant increasing or decreasing trends and did not change substantially. However, there were several NDVI anomalies, indicating uncharacteristically large decreases in greenness that can likely be attributed to sensor errors. On the other hand, the Texan study region had an outlier value observed around 2016 and suffered from large decreases in NDVI following 2021. Both Florida and Texas had positive autocorrelations, with Florida having much higher autocorrelation than Texas, with a much smaller range of observed correlations. With respect to the Palmer Drought Severity Index, for both regions, the distribution of correlations were similar regardless of whether the lags were from 5 days ago or a month ago. In Florida, the correlations were notably more negative, while Texas displayed both positive and negative correlations. While the vegetation dynamics of coastal mangroves in North America have been noted to show variation, this study indicated that these climate change and anthropogenic disturbances have not uniformly impacted these ecosystems and portions of them have remained stable.