Quantifying the Impact of Hydrological Connectivity on Salt Marsh Vegetation in the Liao River Delta Wetland

Kexin Chen; Limei Qu; Pifu Cong; Shuxiu Liang; Zhaochen Sun; Jianbo Han

doi:10.1007/s13157-023-01693-4

Quantifying the Impact of Hydrological Connectivity on Salt Marsh Vegetation in the Liao River Delta Wetland

Wetlands (Wilmington). 2023;43(5):45. doi: 10.1007/s13157-023-01693-4. Epub 2023 May 3.

Authors

Kexin Chen^{1

2}, Limei Qu², Pifu Cong², Shuxiu Liang¹, Zhaochen Sun¹, Jianbo Han²

Affiliations

¹ State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, No.2 Linggong Road, Ganjingzi District, Dalian, 116024 China.
² National Marine Environmental Monitoring Center, Dalian, 116023 China.

Abstract

Salt marshes play a critical role in ecological functioning and have significant economic value. Hydrological elements are considered to be one of the major contributors to salt marsh degradation. However, how hydrological connectivity affects salt marshes remains poorly investigated at fine scales. This paper used spatial analysis and statistical methods to investigate the impact of hydrological connectivity on the spatial and temporal distribution characteristics of salt marsh vegetation in two natural succession areas of the Liao River Delta wetland in 2020 and 2021 by selecting vegetation area, NDVI, tidal creeks area, distance to tidal creeks, and the Index of Connectivity, using 1 m Gaofen-2 data and 0.2 m aerial topographic data. The study found that the area and growth status of vegetation and the overall connectivity in 2021 were better than that in 2020, while the west bank of the Liao River was better than that on the east bank. Phragmites australis showed a round island distribution pattern primarily at the end of tidal creeks. The differences between different hydrological connectivity and vegetation area were significant in 2021. The vegetation area was the largest under poor and moderate connectivity. We also found that within a distance range of 0-6 m from tidal creeks, the vegetation area increased with increasing distance, but beyond 6 m, the vegetation area decreased with increasing distance. Our results showed that poor and moderate connectivity conditions were more suitable for vegetation growth. The threshold value of 6 m can provide an important reference for wetland vegetation restoration in the Liao River Delta wetland.

Supplementary information: The online version contains supplementary material available at 10.1007/s13157-023-01693-4.

Keywords: Hydrological connectivity; Natural succession areas; Remote sensing; Salt marsh; Wetland restoration.

© The Author(s), under exclusive licence to Society of Wetland Scientists 2023, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.