Affiliation:
1. Ocean College, Zhejiang University, Zhoushan 316021, China
2. Ocean Academy, Zhejiang University, Zhoushan 316021, China
3. Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
4. Baruch Institute for Marine & Coastal Sciences, University of South Carolina, SC 29208, USA
Abstract
This study mapped the areal extent, identified the species composition, and analyzed the changes of salt marshes in the intertidal zone of China during the period 1985–2019. With the aid of the cloud platform of the Google Earth Engine, we selected Landsat 5/8 and Sentinel-2 images and used the support vector machine classification method to extract salt marsh information for the years of 1985, 1990, 1995, 2000, 2005, 2010, 2015, and 2019. Seven major species of salt marshes:
Phragmites australis
,
Suaeda
spp.,
Spartina alterniflora
,
Scirpus mariqueter
,
Tamarix chinensis
,
Cyperus malaccensis
, and
Sesuvium portulacastrum
were identified. Our results showed that salt marshes are mainly distributed in Liaoning, Shandong, Jiangsu, Shanghai, and Zhejiang, with varying patterns of shrinking, expansion, or wavering in different places. The distribution of salt marshes has declined considerably from 151,324 ha in 1985 to 115,397 ha in 2019, a drop of 23.7%. During the same period, the area of native species has dropped 95.4% from 77,741 ha to 3,563 ha for
Suaeda
spp. and 45.1% from 60,511 ha to 33,193 ha for
P. australis
; on the contrary, the area of exotic species,
S. alterniflora
, has exhibited a sharp rise from just 99 ha to 67,527 ha. For the past 35 years, the driving factors causing salt marsh changes are mainly land reclamation, variations in water and sand fluxes, and interspecific competition and succession of salt marsh vegetation. These results provide fundamental reference information and could form the scientific basis for formulating policies for the conservation and utilization of salt marsh resources in China.
Funder
Fundamental Research Funds for the Zhejiang Provincial Universities
Ministry of Natural Resources
Publisher
American Association for the Advancement of Science (AAAS)
Reference64 articles.
1. Salt marshes and salt deserts of the world;Chapman V. J.;Journal of Ecology,1974
2. Distribution of Spartina spp. along China's coast;Zuo P.;Ecological Engineering,2012
3. Opportunities for blue carbon strategies in China;Wu J.;Ocean and Coastal Management,2020
4. The considerable environmental benefits of seaweed aquaculture in China;Zheng Y.;Stochastic Environmental Research and Risk Assessment,2019
5. Losses of salt marsh in China: Trends, threats and management
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