Tidal and meteorological influences on the growth of invasive Spartina alterniflora: evidence from UAV remote sensing
Tidal and meteorological influences on the growth of invasive Spartina alterniflora: evidence from UAV remote sensing
复制标题
潮汐和气象对入侵互花米草生长的影响：来自无人机遥感的证据
DOI：
10.3390/rs11101208
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发表时间：
2019
期刊：
影响因子：
5
通讯作者：
Morris JT
中科院分区：
文献类型：
--
作者：
Zhu Xudong;Meng Lingxuan;Zhang Yihui;Weng Qihao;Morris JT
互花米草对中国滨海湿地的快速入侵引起了人们的广泛关注。许多野外和遥感研究已经研究了互花链霉菌入侵的时空动态，但在斑块和景观尺度上对互花链霉菌入侵及其潜在机制的空间显式定量分析还很少报道。为了填补这一认识空白，我们集成了多时相无人机图像、光探测和测距数据以及潮汐和气象时间序列来探索亚热带滨海湿地(福建张江口湿地，中国)潮间带互花米草的生长潜力(横向扩张率和冠层绿度)。斑块扩展分析表明，该湿地孤立的互花米草斑块在过去几年中经历了较高的横向扩展(2014-2017年平均直径为4.28m/年)，横向扩展速率(y，m/年)随着淹没程度的增加(x，h/d；3≤x≤18)呈显著下降趋势：Y=−0.17x+5.91，R2=0.78。对冠层绿度的分析表明，互花米草生长潜力的季节性受温度(皮尔逊相关系数r=0.76)和降水(r=0.68)的影响，生长潜力在初夏/盛夏气温高、降水充足时达到峰值。综上所述，互花米草的生长潜力受潮汐和气象条件共同调控，其中空间异质性受潮汐淹没控制，时间变化受温度和降水共同控制。据我们所知，这是第一次在斑块和景观尺度上考察潮汐和气象条件对互花米草空间异质性(潮间带)和时间变化(年内和年间)的影响的空间显式定量研究。这些发现可以作为关键的经验证据，帮助回答沿海盐沼如何应对气候变化，并评估沿海盐沼对海平面上升的脆弱性和复原力。我们基于无人机的方法可以应用于许多类型的植物群落分布。
Rapid invasion of Spartina alterniflora into Chinese coastal wetlands has attracted much attention. Many field and remote sensing studies have examined the spatio-temporal dynamics of S. alterniflora invasion; however, spatially explicit quantitative analyses of S. alterniflora invasion and its underlying mechanisms at both patch and landscape scales are seldom reported. To fill this knowledge gap, we integrated multi-temporal unmanned aerial vehicle (UAV) imagery, light detection and ranging (LiDAR)-derived elevation data, and tidal and meteorological time series to explore the growth potential (lateral expansion rates and canopy greenness) of S. alterniflora over the intertidal zone in a subtropical coastal wetland (Zhangjiang estuarine wetland, Fujian, China). Our analyses of patch expansion indicated that isolated S. alterniflora patches in this wetland experienced high lateral expansion over the past several years (averaged at 4.28 m/year in patch diameter during 2014–2017), and lateral expansion rates ( y , m/year) showed a statistically significant declining trend with increasing inundation ( x , h/day; 3 ≤ x ≤ 18 ): y = − 0.17 x + 5.91 , R 2 = 0.78 . Our analyses of canopy greenness showed that the seasonality of the growth potential of S. alterniflora was driven by temperature (Pearson correlation coefficient r = 0.76 ) and precipitation ( r = 0.68 ), with the growth potential peaking in early/middle summer with high temperature and adequate precipitation. Together, we concluded that the growth potential of S. alterniflora was co-regulated by tidal and meteorological regimes, in which spatial heterogeneity is controlled by tidal inundation while temporal variation is controlled by both temperature and precipitation. To the best of our knowledge, this is the first spatially explicit quantitative study to examine the influences of tidal and meteorological regimes on both spatial heterogeneity (over the intertidal zone) and temporal variation (intra- and inter-annual) of S. alterniflora at both patch and landscape scales. These findings could serve critical empirical evidence to help answer how coastal salt marshes respond to climate change and assess the vulnerability and resilience of coastal salt marshes to rising sea level. Our UAV-based methodology could be applied to many types of plant community distributions.