Publications

Shi, K; Sun, C; Li, JL; Liu, YC; Cai, XY (2025). Quantifying Greenness Balance in Coastal Wetlands from Spartina Alterniflora Invasion and Tidal Flat Reclamation Using a Continuous Change Detection Model. ESTUARIES AND COASTS, 48(4), 107.

Abstract
Greenness is a comprehensive proxy for vegetation status in response to climate and anthropogenic stressors and has drawn worldwide attention. Spartina alterniflora invasion and tidal flat reclamation were heavily burden China's coastal wetlands, leading to dramatic changes of the greenness. In this study, we constructed a continuous change detection model to recognize land cover changes in coastal wetlands, especially for those related to Spartina alterniflora (S. alterniflora) invasion and tidal flat reclamation. Also based on the model, we further established specific rules to quantify different processes of greenness balance, including climate change-driven greenness and land cover change-driven greenness. The coastal wetlands in Zhejiang Province, which has the longest coastline in China, were used for time-series monitoring of land cover changes and greenness dynamics during 1990-2020. The overall accuracy of land cover identification reached 88.3%, and 78.6% detected changes had a time discrepancy within 1 year, demonstrating the high reliability of the continuous change detection model. Over the past 30 years, the direct conversion from tidal flats to other land cover types was most conspicuous (1398.4 km2), with nearly three quarters of these conversions related to S. alterniflora invasion and tidal flat reclamation. Among the reclaimed tidal flats, more than 70% (655.0 km2) was converted to aquaculture ponds and buildings, while approximately 30% (273.2 km2) were revegetated into farmland. As a result, the overall coastal wetlands exhibited a significant greening trend, with total greenness increasing by 0.092 in NDVI, shifting from negative to positive. Among the increment, climate change-driven greenness from vegetation (e.g., S. alternilfora, farmland, and other wetland vegetation) accounted for 54.5%, contributing even slightly more than land cover change-driven greenness from non-vegetation to vegetation. This work provides valuable insights for evaluating the value of ecosystem services by monitoring the greenness of highly dynamic areas, and provides theoretical support for the formulation of coastal wetland management policies and biological invasion prevention and control.

DOI:
10.1007/s12237-025-01548-7

ISSN:
1559-2731