IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (Jan 2025)
Early Invasion Process Monitoring of Spartina Alterniflora Using Long Time Series High-Resolution Satellite Remote Sensing Imagery
Abstract
Spartina alterniflora (S. alterniflora) rapidly invade new habitats by seed jumping propagation, and the early invasion process is characterized by discrete large patches and diffuse distribution small-scale patches. Monitoring these early-invasion-stage patches is very important for effectively stopping the S. alterniflora invasion trends. In this study, a long time series of high spatial resolution (0.5 and 1 m) satellite remote sensing images from 2010 to 2020 were used to monitor the early invasion period of S. alterniflora. Using remote sensing technology, the early invasion behavior of S. alterniflora at patch scale was monitored and analyzed in the Yellow River Delta with the object-oriented image segmentation and support vector machine classification methods. The results indicate that the discrete patches were incorporated into bigger patches or gathering regions within a few years: 56.13% of the independent large patches lasted only for 1 year, and only 0.25% of which can last for 10 years. Second, we newly found out that the newborn S. alterniflora seedlings are uniformly distributed between discrete large patches and then quickly aggregate into a large gathering area within the next 2 years. Third, for the area that was undergoing invasion, the mean S. alterniflora coverage rate was stable at approximately 50%. Fourth, dominant factors that determined the invasion trend of S. alterniflora are the elevation of the intertidal zone, the tidal channel distribution and the topographic changes caused by S. alterniflora invasion.
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