Abstract
The overwhelming spread of Spartina alterniflora (S. alterniflora) (smooth cordgrass) over recent decades has put many native plant communities and coastal environments at risk. Therefore, long-term monitoring of S. alterniflora dynamics is necessary to better understand and manage the invasion of the species. However, it is difficult to map Spartina saltmarshes in China on an annual or multiyear epoch basis. To address this issue, we developed a classification approach integrating Google Earth Engine (GEE) and object-based hierarchical random forest (RF) classification, and we applied this approach to quantify the expansion and dieback of S. alterniflora at Dafeng Milu National Nature Reserve, Jiangsu, China during 1993–2020. Results showed that the area of S. alterniflora expanded from 24.48 ha in 1993 to 1564.96 ha in 2010. However, after ecological hydrological engineering and an increase in Elaphures davidianus (Pere David's deer) numbers in 2011, the S. alterniflora area decreased significantly to 944.28 ha in 2020. During 2011–2020, the S. alterniflora area decreased substantially at a rate of 67 ha per year and by 86% in one area studied in Dafeng Milu National Nature Reserve. In 2020, the 944.28 ha of S. alterniflora in the reserve was mainly distributed in mudflats by the sea. Overall, these results show that it is feasible to identify S. alterniflora using the GEE platform and object-based hierarchical RF classification; moreover, this approach could improve understanding and management of this invasion species.
Highlights
BIOLOGICAL invasion is a key ecological issue in coastal wetlands; it poses a challenge to the protection of biodiversity and has negative effects on ecosystem functions [1]–[4]
We proposed a classification approach integrating the Google Earth Engine (GEE) and object-based hierarchical random forest (RF) classification to identify and map S. alterniflora
By applying this classification approach, we revealed the expansion dynamics of S. alterniflora during 1993–2010 and the dieback dynamics during 2011–2020
Summary
BIOLOGICAL invasion is a key ecological issue in coastal wetlands; it poses a challenge to the protection of biodiversity and has negative effects on ecosystem functions [1]–[4]. Studies have found that S. alterniflora has serious effects on native plant communities and the ecological environment of the coastal wetland, which include outcompeting native plant species while damaging the structure and function of the original ecosystem [5], [9]–[11]. S. alterniflora has become a first batch of 16 alien invasive species on the coast of China [6], [12]. There is currently no relevant research on S. alterniflora dieback on the coast of China. Obtaining a long-term holistic view of S. alterniflora in Yancheng will be critical to the success of coastal ecosystem conservation and ecological management. Long-term holistic datasets on S. alterniflora dynamics are not currently available
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
