联合星载光学和SAR影像的漳江口红树林与互花米草遥感监测     

董迪  曾纪胜  魏征  严金辉 《热带海洋学报》2020,39(2):107-117

文章以福建省漳江口国家级红树林自然保护区为研究区, 提出了一种联合星载光学和合成孔径雷达(SAR)影像的红树林与互花米草分布的自动提取算法, 提取研究区内红树林和互花米草的空间分布。本研究选择2016年、2017年和2018年各一景低潮时的Sentinel-2 A光学影像数据, 获取植被和其他地物的光谱和纹理信息。算法首先基于归一化植被指数、增强型植被指数、地表水分指数以及数字高程模型的相关规则计算红树林和互花米草的潜在分布区; 通过随机森林分类算法区分红树林和互花米草, 2016年、2017年和2018年影像的分类总体精度和Kappa系数分别为98.53%和0.980、96.52%和0.952、98.71%和0.978, 分类效果良好; 使用当年所有Sentinel-1 A/B的SAR影像获得研究区的常年海水分布范围, 使用与海水交界的判据, 实现红树林、互花米草提取范围的优化。研究表明, 研究区2016年、2017年和2018年红树林总面积分别为56.85hm²、59.88hm²和58.61hm², 互花米草总面积分别为109.23hm²、124.00hm²和142.39hm², 与前人的研究成果在红树林和互花米草的空间分布和面积量级上有较好的一致性。  相似文献   

底物和电子受体对互花米草湿地沉积物甲烷产生潜力的影响   总被引：1，自引：0，他引：1  

鄂焱  仝川  王维奇  姚顺  杨红玉 《湿地科学与管理》2010,6(1):49-54

采用室内厌氧培养法研究闽江河口潮汐盐湿地甲烷产生不同底物(醋酸、甲醇和三甲胺)及电子受体(SO42-、NO3-和NH4+)对外来入侵种互花米草Spartinaalterniflora湿地表层沉积物甲烷产生潜力的影响,结果表明:盐湿地非竞争性甲烷产生底物中的甲醇对互花米草湿地表层沉积物甲烷产生潜力的促进作用最大,高于醋酸和三甲胺,且3种底物的添加均在培养5d后对沉积物甲烷产生潜力的促进作用最为明显;随着培养时间的增加,不同浓度的SO42-、NO3-、NH4+的添加对沉积物甲烷产生潜力的影响呈现出抑制作用或无抑制作用2种结果,添加电子受体的浓度越高,对沉积物甲烷产生潜力的抑制作用越显著。  相似文献   

射阳河口互花米草入侵对大型底栖动物群落的影响   总被引：1，自引：0，他引：1  

侯森林  余晓韵  鲁长虎 《海洋湖沼通报》2012,(1):137-146

2008年11月至2009年10月,在盐城自然保护区射阳河口滩涂分别于潮间带、潮上带和潮沟中设置互花米草区与非米草区2类对照样地(共6类生境),按月份取样来研究大型底栖动物群落特征的差异,探讨互花米草入侵对底栖动物的影响。共发现大型底栖动物22种,隶属3门4纲17科,其中软体动物13种,节肢动物6种,环节动物3种。米草区和非米草区的物种组成不同,各生境在不同月份大型底栖动物的物种数、密度、生物量和Shannon-Wiener多样性指数均在不断波动,在潮间带上述指标均为In>Ig,潮上带除密度外均为Sn>Sg,潮沟边滩除个别月份外均为Cg>Cn;3类互花米草生境中大型底栖动物群落各项指标月间变动趋势基本一致(仅个别月份例外),均表现为Cg>Sg>Ig,互花米草生境存在共同的优势种,但数量有一定的差异。分别对潮间带、潮上带和潮沟中互花米草区与非米草区2类对照样地的物种数、密度、生物量以及Shannon-Weiner多样性指数H’进行生境-月份间无重复双因素方差分析,结果显示潮间带2类对照样地各项指标在生境间差异均极显著,月份间差异均不显著;潮上带2类对照样地各项指标生境间存在极其显著的差异(除密度外),月份间差异显著(除多样性外);潮沟2类对照样地生境间差异显著(除生物量外),月份间差异均显著。研究结果表明不同生境中的互花米草对底栖动物的影响不甚相同:潮间带互花米草的入侵降低了大型底栖动物的物种数、密度、生物量和多样性;潮沟米草的入侵提高了大型底栖动物的物种数、密度和多样性;而潮上带米草入侵对大型底栖动物的各指标影响不一。  相似文献   

Sediment remobilisation from decomposing cordgrass (Spartina anglica) patches on a wave‐exposed intertidal flat     

Andrew Swales  Ron Ovenden  Iain T. MacDonald  Andrew M. Lohrer  Karen L. Burt 《新西兰海洋与淡水研究杂志》2013,47(6):1305-1319

Abstract

Concerns about the potential adverse effects of Spartina invasion on New Zealand estuaries, such as habitat loss and degradation, have led to herbicide use to control its spread. An experiment was conducted in the Manukau Harbour (New Zealand) to determine sediment remobilisation rates (?E) from herbicide‐treated S. anglica patches. Paired treatment and control patches (≤25 m diam.) were monitored at two sites 500 m apart with different wave exposures. Above‐ (AGB) and below‐ground (BGB) biomass decomposition and AE were determined from repeat surveys over c. 2.5 years. Work done by waves (W), which integrates wave‐energy dissipation at the bed over time, was used as a surrogate measure of sediment transport potential. Complete AGB loss occurred in both treated patches within 3 months of initial herbicide application, whereas BGB (a matrix of roots and rhizomes) persisted much longer. An exponential decay model (r ² = 0.6) fitted to the site‐two treatment data predicted an c. 85% reduction in BGB after 5 years, whereas the BGB changes for the larger and more heterogeneous site‐one treatment were more complex. BGB was a better predictor of average bed elevation than AGB in multiple regression models and, although bed elevation decreased through time and with waves, BGB was positively related to bed elevation at both sites. AE was similar for both treatment patches (c. 0.05 and c. 0.06 m yr^‐1, P < 0.001, r² ≥ 0.97) and complete sediment loss was predicted to occur within 6–10 years. The site‐one control patch accumulated sediment (0.01 m yr^‐1 , P < 0.001, r ² = 0.81) whereas the more wave‐exposed site‐two control eroded (0.01 m yr^‐1, P = 0.0017, r ² = 0.61). The potential for adverse sediment effects resulting from Spartina control at wave‐exposed sites will be minimal if the treated areas are small relative to the size of the estuary.  相似文献   

On the potential of plant species invasion influencing bio‐geomorphologic landscape formation in salt marshes          下载免费PDF全文

Christian Schwarz  Tom Ysebaert  Wouter Vandenbruwaene  Stijn Temmerman  LiQuan Zhang  Peter M. J. Herman 《地球表面变化过程与地形》2016,41(14):2047-2057

Species invasions are known to change biotic and abiotic ecosystem characteristics such as community structure, cycling of materials and dynamics of rivers. However, their ability to alter interactions between biotic and abiotic ecosystem components, in particular bio‐geomorphic feedbacks and the resulting landscape configuration in tidal wetlands, such as tidal channels have not yet been demonstrated. We studied the impact of altered bio‐geomorphic feedbacks on geomorphologic features (i.e. tidal wetland channels), by comparing proxies for channel network geometry (unchanneled flow lengths, fractal dimension) over time between non‐invaded and invaded salt marsh habitats. The non‐invaded habitats (the south of eastern Chongming Island, Yangtze estuary, China) show little change in network geometry over time with a tendency for an increased drainage density. The invaded site (salt marshes in the north of eastern Chongming Island invaded by the exotic plant species Spartina alterniflora) showed a decreasing tendency in channel drainage density throughout and after the species invasion. This suggests that species invasions might not only affect biotic ecosystem characteristics, but also their ability to change bio‐geomorphic feedback loops, potentially leading to changes in existing geomorphologic features and therefore landscape configuration. Our results further suggest that the species invasion also altered sediment composition. Based on observations we propose a mechanism explaining the change in channel drainage density by an alteration in plant properties. The physical and physiological characteristics of the invading species Spartina alterniflora clearly differ from the native species Scirpus mariqueter, inducing different bio‐geomorphic feedback loops leading to the observed change in salt marsh channel configuration. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

江苏中部海岸互花米草扩展对滩涂围垦的响应   总被引：1，自引：0，他引：1  

朱冬  高抒 《地理研究》2014,33(12):2382-2392

根据2001-2013年遥感影像和野外观测数据,对江苏中部海岸互花米草(Spartina alterniflora Loisel)在滩涂围垦期间的扩展过程进行定量化分析。结果显示：2001-2013年互花米草扩展对围垦的响应大体分为三个阶段：2001-2007年,海堤外米草面积较大,每年新增米草面积及米草年扩展率均和新增围垦面积变化同步,且相关性显著;2008-2010年,海堤外米草面积较小,但米草年扩展率仍然较高;2011-2013年,随着围垦的持续进行,米草扩展进入稳定期。因此,互花米草扩展对于滩涂围垦的不同速率和阶段具有不同的响应。若围垦时保留足够宽度的堤前米草,则围垦可以提高米草的年扩展率,其机理是互花米草种子产量和前缘淤积环境是影响米草扩展的主要因素,而围垦对这两方面都有影响。在后期滩涂围垦时,应保证堤外米草宽度在0.9~1 km之间,实现土地资源的可持续利用。  相似文献   

基于无人机高光谱的外来入侵种互花米草遥感监测方法研究——以黄河三角洲为研究区     

李晓敏  张杰  马毅  任广波 《海洋科学》2017,41(4):98-107

互花米草(Spartina alterniflora)入侵性非常强,已被正式纳入我国第一批外来入侵物种名单。互花米草的疯狂蔓延已影响到当地土著物种的生长和空间分布,因此有关管理部门迫切需要互花米草的空间分布和扩散动态数据,但目前还没有一个有效的监测手段。针对这一需求,本文作者提出了基于无人机高光谱的外来入侵种互花米草遥感监测研究方案,拟以黄河三角洲为研究区,利用无人机高光谱遥感新型技术,分析不同情形下(不同生长状况、不同观测条件、不同环境条件等)互花米草的光谱特征,建立鲁棒的互花米草遥感检测模型,研究互花米草无人机高光谱图像高效获取方法,以实现互花米草的高效、准确监测,为亟需的外来入侵种互花米草业务化监测提供有效的技术手段。  相似文献   

闽江河口湿地互花米草与芦苇光合特性及适应性研究     

林培治  李守中  赵颖  王英杰 《湿地科学与管理》2012,(4):45-48

互花米草在闽江河口鳝鱼滩湿地中潮滩的入侵及快速扩张,已严重威胁到鳝鱼滩湿地的生物多样性及土著种沼泽植物生态系统的结构与功能。为了从植物光合速率的角度分析互花米草入侵及快速扩张的生理生态学机制,利用Li-6400便携式光合作用仪测定了互花米草与土著种芦苇的光合速率日进程及光合光响应曲线。结果表明,互花米草净光合速率的日均值与最大值均大于芦苇,互花米草可积累更多的光合作用产物,使其具有更快的生长速率和初级生产力。根据两种植物的光合光响应曲线可以看出,互花米草利用光合有效辐射的能力更强,显示出互花米草的高适应性。  相似文献   

基于高分辨率遥感影像的湿地互花米草-芦苇混合交错带提取方法     

姚红岩  刘浦东  施润和  张超 《地球信息科学学报》2017,19(10):1375-1381

互花米草是中国东部河口滩涂湿地主要入侵物种之一,其与本地物种芦苇竞争生长,形成了大范围的混合交错带。该交错带是研究湿地生态系统动态变化的重要信息,但因2种物种光谱的相似性及其在交错带的组成复杂性,使利用遥感技术提取交错带难度较大。因此,本文提出了一种将二者生长物候差异与其光谱特征相结合,考虑二者海陆位置分布差异,运用实测剖面观测数据确定光谱指标和阈值的综合提取方法。运用高分一号多光谱遥感数据,通过分析不同时相互花米草与芦苇冠层光谱差异,确定用来提取混合交错带的高分遥感影像,实现了研究区互花米草-芦苇混合交错带的提取。结果表明：不同时相宜选用不同的提取指标,本研究中在春季选择了近红外波段反射率,而秋季则选择了红波段反射率;2个时相的混合交错带范围存在明显差异,客观反映了互花米草与芦苇在不同季节的竞争状况。  相似文献   

Sedimentation rates in the Wanggang salt marshes, Jiangsu     

WANG Aijun  GAO Shu  JIA Jianjun  PAN Shaoming 《地理学报》2005,15(2):199-209

Coastal salt-marshes represent an important coastal wetland system. The total area of coastal wetlands exceeds 5000 km2 in Jiangsu Province, China, but it is decreasing rapidly in response to the intense reclamation activities and coastal erosion along a part of the coastline. Hence, two types of plants, Spartina angelica and Spartina alterniflora, were introduced successively into the Jiangsu coastal areas, in order to protect the coastline from erosion and to increase the accumulation rate. Pb-210 and Cs-137 analyses were carried out for sediment samples from the salt-marshes of Wanggang to determine the sedimentation rate, on the basis of an evaluation of the background activity values and the factors affecting the enrichment of Pb-210. Analysis of a typical sediment column of the tidal flat shows that there is weak absorption of Pb-210 in the silt-dominated sediment. Because of the influences of factors such as storm events, bioturbation, material sources and analytical error, some abnormal data points appear in the Pb-210 record. After ignoring these data the calculated sedimentation rate was 3.3 cm yr-1 on average. Based upon analysis of the Cs-137 dating, the rate since 1963 was 3.1 cm yr-1 on average, similar to the data by Pb-210 dating and the previous studies. The dating results show that there were three stages of sedimentation, with the most rapid accretion being taking place after Spartina angelica was introduced into the area. The study also shows that at the stage of Spartina alterniflora growth, the accretion rate was higher than on the flat surface with the same elevation without the cover of this plant.  相似文献