Spatial–temporal variations in vegetation phenology and their driving mechanisms in the coastal wetlands of the Liao River estuary

Coastal wetland vegetation phenology is a key indicator of ecosystem responses to environmental change. However, quantifying the anthropogenic impact amidst climate variations remains a challenge. Utilising the global 30 m Seamless Data Cube generated from Landsat and MODIS Terra constellations, we reconstructed continuous land surface phenology (LSP) time series (2000−2022) for three dominant vegetation types ( S.salsa , Phragmites australis (reed), and rice) in the Liao River Delta. Our analysis reveals a significant phenological shift: the end of the season (EOS) was delayed by 1.02 days per year, leading to a synchronous extension of the growing season length (LOS) by 1.09 days per year. Crucially, random forest analysis factors reflecting human activity intensity—GDP, population, nighttime light (NTL), and artificial land area—are the more important factors, exerting stronger influences on phenology than climatic and soil factors. Partial least squares path modelling (PLS-PM) further confirmed that socioeconomic development reshapes local microclimate and soil conditions through human activities, ultimately emerging as the more important factors. This study underscores the overwhelming impact of human disturbances on coastal wetland phenology and provides a critical scientific basis for the sustainable management of these vulnerable ecosystems.