Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing, 311300, China.
School of Environmental & Resource Sciences, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China.
BMC Ecol. 2020 Feb 6;20(1):7. doi: 10.1186/s12898-020-00277-8.
Spartina alterniflora is an invasive plant on the coast of China that replaces native vegetation and has a serious negative impact on local ecosystems. Monitoring the spatial distribution of S. alterniflora and its changes over time can reveal its expansion mechanism, which is crucial for the management of coastal ecosystems. The purpose of this study was to map the distribution of S. alterniflora in Zhejiang Province from 1985 to 2015 using a time series of Landsat TM/OLI images and analyze the temporal and spatial patterns of expansion of this species.
After analyzing the distribution of coastal vegetation, the vegetation index was calculated based on Landsat images for 4 years (1985, 1995, 2005 and 2015). According to a threshold determined based on expert knowledge, the distribution of S. alterniflora in Zhejiang Province was extracted, and the temporal and spatial changes in the distribution of S. alterniflora were analyzed. The classification accuracy was 90.3%. S. alterniflora has expanded rapidly in recent decades after being introduced into southern Zhejiang. Between 1985 and 2015, S. alterniflora increased its area of distribution by 10,000 hm, and it replaced native vegetation to become the most abundant halophyte in tidal flats. Overall, S. alterniflora expanded from south to north over the decades of the study, and the fastest expansion rate was 463.64 hm/year, which occurred between 1995 and 2005. S. alterniflora was widely distributed in the tidal flats of bays and estuaries and expanded outward as sediment accumulated.
This study reveals the changes over time in S. alterniflora cover in Zhejiang and can contribute to the control and management of this invasive plant.
互花米草是中国沿海的一种入侵植物，它取代了本地植被，对当地生态系统造成了严重的负面影响。监测互花米草的空间分布及其随时间的变化，可以揭示其扩张机制，这对于沿海生态系统的管理至关重要。本研究旨在利用多时相 Landsat TM/OLI 影像，对 1985 年至 2015 年浙江省互花米草的分布进行制图，并分析该物种的时空扩张格局。
通过对沿海植被分布进行分析，基于 Landsat 影像计算植被指数，共选取了 4 年（1985 年、1995 年、2005 年和 2015 年）的数据。根据专家知识确定的阈值，提取了浙江省互花米草的分布，并分析了互花米草分布的时空变化。分类精度为 90.3%。互花米草在引入浙江南部后近几十年来迅速扩张。1985 年至 2015 年，互花米草的分布面积增加了 1 万 hm，取代了本地植被，成为潮滩最丰富的盐生植物。总体而言，几十年来，互花米草从南向北扩张，扩张速度最快的时期是 1995 年至 2005 年，达到 463.64 hm/年。互花米草广泛分布于海湾和河口的潮滩上，并随着沉积物的积累向外扩张。
本研究揭示了浙江省互花米草覆盖的时间变化，可以为控制和管理这种入侵植物提供参考。
