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1.
海草床是海岸带最富生产力的生态系统之一,支撑着各种各样的伴生生物。热带的印度和太平洋地区被认为拥有海草植物种类多样性最高,且分布面积最广,然而,这个区域的海草床大型底栖生物我们知之甚少。为了填补认知的空白,我们在该区域开展了一项生态调查,旨在描述该区热带海草床大型底栖生物的丰度和多样性,以及确定大型底栖生物丰度、物种丰富度和群落结构是否明显存在断面内的站间变化和样地间变化。2014年5月和2015年10月我们分别在北苏拉威西省东海岸和西海岸开展野外工作,使用柱状取样器采集海草床大型底栖生物样品。所得样品共计鉴定14大类149种底栖生物,种类最为丰富的类别为多毛类(56种,占26%的总个体数),十足类(20种,占9%的总个体数)和端足类(18种,占35%的总个体数)。东、西海岸海草床大型底栖生物表现出不同的空间分布模式。在东海岸,同一断面的大型底栖生物和端足类的丰度存在显著的站间差异;而在西海岸,大型底栖生物和多毛类的种类丰富度和丰度都表现出明显的站间变化,这可能归结于同一断面底质不均所造成。单因素ANOSIM以及MDS排序表明了北苏拉威西省东海岸和西海岸海草床大型底栖生物群落结构存在显著不同,正好对应于将海草床分成两大类型的栖息地,即西海岸的红树林-海草床-珊瑚连续体和东海岸的海草床-珊瑚连续体。与在热带海区开展的其他研究相比,本研究的大型底栖生物丰度和多样性处于中等水平。东、西海岸海草床大型底栖生物群落存在显著区别,其原因可能源于多方面,包括了沉积物模式,海草床结构和时间变化。  相似文献   

2.
于2007年4月对山东南部近海进行了32个站位的大型底栖动物研究,共发现大型底栖动物170种,其中多毛类87种,软体动物25种,甲壳类47种,棘皮动物7种,其他类群4种。排名前3位的优势种是背蚓虫(Notomastus latericeus)、东方缝栖蛤(Hiatella orientalia)和寡鳃齿吻沙蚕(Nephtys oligobranchia)。研究海域大型底栖动物总平均丰度为1494 ind/m~2,总平均生物量为13.88 g/m~2,生物多样性指数H′、J′和d的平均值分别为:3.856、0.805和4.004。在30%相似度水平上,该海域大型底栖动物可划分为4个群落。综合H′和ABC曲线的结果,山东南部海域底栖生态环境较好。  相似文献   

3.
Two areas of the Venice lagoon populated by seagrasses (three stations covered by Cymodocea nodosa (Ucria) Asherson, Zostera marina Linnaeus, Zostera noltii Hornemann) or seaweeds (two stations: one covered by Ulva rigida C. Agardh and another at present without seaweed biomass) were monitored by means of six surveys over a year in order to study macrofaunal composition and seasonal changes. The seagrass stations showed a mean species richness (28-30 S m(-2)), individual abundance (1854-4018 N m(-2)) and biomass (22.3-37.7 g m(-2) ash-free-dry-weight, AFDW) ca. 3-8 times higher than those populated by seaweeds (10-15 S m(-2), 494-1395 N m(-2) and 5.6-13.7 g m(-2) AFDW). Differences among seagrass or seaweed stations were much lower. The Ulva-dominated station showed a macrofauna completely different both from the other stations and the communities recorded ca. 30 years ago, before the prolific growth of Ulva. In this station, frequent biomass decompositions and anoxic crises created critical conditions for life favouring organisms with reduced life cycles, younger individuals and the epifaunal species instead of the infaunal ones. In particular, Ulva grazers and scrapers such as Gammarus aequicauda Stock and Gibbula adriatica Philippi were found to be by far the most abundant species, whereas the taxa characteristic of the associations found in the past, in the presence of seagrasses or seaweeds and typical of low eutrophicated environments, appear strongly reduced. Marked differences in the macrophyte dominance and in the bio-physico-chemical variables which characterise the main environmental conditions of the Venice lagoon support the different distribution and composition of macrofaunal communities. Seaweed stations appear mainly governed by the seasonal cycles of these un-rooted macrophytes which, by alternating periods of production and decomposition, are responsible for the drastic reduction of macrofauna biodiversity and biomass. Conversely, seagrass stations exhibit a better oxidisation of the environment and show conditions more favourable for macrofauna colonisation, especially in the presence of macrophytes which are characterised by very well developed below-ground systems such as Cymodocea nodosa.  相似文献   

4.
为探讨泉州湾洛阳江口桐花树和秋茄2种红树林生境的大型底栖动物群落是否存在明显差异,于2011年4月至2012年1月对2种红树林生境的大型底栖动物进行了季度定量调查.结果表明:4个季度在2种红树林生境定量取样获得大型底栖动物49种,其中多毛类15种,腹足类8种,甲壳类15种,鱼类3种,昆虫2种,刺胞动物、扁形动物、纽形动物、星虫动物、寡毛类和双壳类各1种.寡鳃齿吻沙蚕(Nephtys oligobranchia)、短拟沼螺(Assiminea brevicula)、弧边招潮蟹(Uca arcuata)、指海葵(Actinia sp.)等在2种生境均有较高的栖息密度,可口革囊星虫(Phascolosoma esculenta)是2种生境的常见种,但栖息密度不高.虽然秋茄生境的大型底栖动物平均生物量高于桐花树生境,但桐花树生境的大型底栖动物群落的物种数、栖息密度、多样性指数(H’)、均匀度指数(J)和丰富度指数(d)均高于秋茄生境.单变量双因素方差分析(Two-way ANOVA)表明,2种红树林生境的大型底栖动物群落的多样性指数和均匀度指数有显著的季节差异、生境差异以及生境×季节差异.聚类分析表明,2种红树林生境的大型底栖动物群落组成的相似性较高,其原因是它们所处的潮区相同、沉积物类型相似和底质粒径相近.  相似文献   

5.
6.
Macrofauna Communities in the Eastern Mediterranean Deep Sea   总被引:1,自引:0,他引:1  
Abstract. During two expeditions with RV ‘Meteor’ in summer 1993 and winter 1997/98 the structural and functional diversity of the benthic system of the highly oligotrophic eastern Mediterranean deep sea was investigated. The macrofauna communities were dominated by polychaetes even at the deepest stations. The fauna at shallow stations was dominated by surface deposit feeders, whereas subsurface deposit feeders and predators generally increased with depth. A high percentage of suspension‐feeding Porifera was found in the Levantine Basin. Mean abundance and number of taxa of both expeditions were significantly correlated to depth and distance to the nearest coast as well as to the total organic carbon (TOC) content in sediments. Numbers of taxa and abundance decreased generally with depth, although lowest numbers were not found at the deepest stations but in the extremely oligotrophic Levantine and Ierapetra Basin. Biomass measured during the second cruise was extremely low in the Ierapetra Basin and comparable to other extreme oligotrophic seas. The significant correlations found for TOC contents and macrofauna with distance to coast during both expeditions apparently reflect the role of hydrographically governed transport of organic matter produced in coastal regions into greater and extreme depths of the Mediterranean Sea. Seasonal differences in macrofauna communities due to seasonal differences in food supply were not found. However, recent large‐scale hydrographic changes (Eastern Mediterranean Transient, EMT) might change the oligotrophy and, thus, the structure of the benthic communities in the Eastern Mediterranean deep sea.  相似文献   

7.
In the tropics and sub-tropics, estuarine environments with mangrove and seagrass habitats provide important structures and resources for diverse communities of benthic organisms. However, temperate estuarine habitats, especially in mangrove areas, may differ significantly in their community associations and interactions. The community composition of benthic macro-fauna was investigated within temperate Matapouri Estuary, northern New Zealand. The density and distribution of fauna were sampled within six distinctive habitats (mangrove stands, pneumatophore zones, Zostera beds, channels, banks, and sand flats), within four sampling events between December 2002 and September 2003. Each type of habitat was replicated seven times within different locations in the estuary. Counts of all infauna and epifauna within four replicate cores were recorded from each habitat and location. Multidimensional scaling plots were used to identify differences in structure and composition of assemblages among habitats and locations within each sampling event. Results from these benthic samples indicate that Matapouri Estuary has a high overall biodiversity, with distinctive faunal assemblages found within different habitats, and some seasonal variations also apparent. In terms of both number of individuals and taxa per unit area, seagrass beds had the highest numbers and mangrove areas had the lowest numbers, with all other habitats in between. Some locations were found to support a high diversity of organisms across habitats, while other locations had high densities of a few species only. Several physical and biological differences between tropical/sub-tropical and New Zealand's temperate mangrove habitats are put forth as potential reasons for the lower density and diversity of the benthic component observed herein. Further ongoing studies aim to elucidate the structure and interactions within food webs in this estuarine ecosystem.  相似文献   

8.
The productivity and health of seagrass depend on the combined inputs of nutrients from the water and sediments in which they grow and the microbiota with which they live intimately. However, little is known about the composition and diversity pattern of single-celled benthic eukaryotes in seagrass meadows. Here, we investigated how the structure and diversity of the benthic microeukaryotic community vary with respect to season, location, and seagrass colonization, by applying 18S rRNA gene amplicon sequencing for 96 surface sediment samples that were collected from three different seagrass habitats through four seasons. We found that benthic microeukaryotic communities associated with seagrass Zostera japonica exhibited remarkable spatial and seasonal variations, as well as differences between vegetated and unvegetated sediments. Diatoms and dinoflagellates predominated in the benthic microeukaryotic communities, but they were inversely correlated and displaced each other as the dominant microbial group in different seasons or habitats. Mucoromycota was more prevalent in vegetated sediments, whereas Lobulomycetales and Chytridiales had higher proportions in unvegetated sites. Total organic carbon and total organic nitrogen were the most important environmental factors in driving the microeukaryotic assemblages and diversity. Our study expands the available knowledge on the biogeographic distribution patterns and niche preferences for benthic microeukaryotes in seagrass systems.  相似文献   

9.
渤海3个河口区底栖硅藻群落的时空变化特征   总被引:1,自引:0,他引:1  
底栖硅藻是河口泥滩系统中的重要初级生产者,其群落结构的时空变化可显著影响到河口底栖动物生产力。本研究选取渤海区域的大辽河口、汉沽河口和黄河口为研究对象,分析了泥滩中底栖硅藻群落结构的季节变化特征(2014?2016年)与空间差异,并探讨了环境因素的影响作用。结果表明,3个河口区底栖硅藻多样性和生物量高峰均出现在秋季,优势种存在显著季节演替特征;在空间上,大辽河口和汉沽河口的底栖硅藻生物量显著高于黄河口。底栖硅藻群落结构与多种环境因子的相关性分析表明,温度和营养盐浓度变化对底栖硅藻群落的季节性特征影响显著;河口沉积物的粒径、潮差与径流量可能是造成底栖硅藻群落空间差异的重要因素,黄河口较低的底栖硅藻生物量显著受限于较粗的沉积物粒径和显著的磷限制。  相似文献   

10.
本文根据2014年至2017年在厦门文昌鱼保护区黄厝、南线十八线、鳄鱼屿和小嶝岛四处潮下带以及参照点白城潮下带获得的大型底栖动物和沉积物粒径数据,探讨底质细化对厦门潮下带文昌鱼栖息地大型底栖动物群落的影响。聚类分析表明个别黏土含量较高的取样站没有发现文昌鱼且大型底栖动物种数少。单因素方差分析表明,厦门潮下带部分大型底栖动物群落参数和优势种数量存在显著差异。底质粒径分析表明, 2017年9月,鳄鱼屿和白城潮下带黏土和粉砂含量高于黄厝、南线十八线和小嶝岛潮下带的黏土和粉砂含量。2016年夏季黄厝、南线十八线潮下带黏土和粉砂含量明显高于2014年夏季的黏土和粉砂含量。相关分析表明,5个大型底栖动物群落参数如物种数、栖息密度、生物量、多样性指数(H′)和丰度指数(d), 7个常见种的栖息密度和生物量与粉砂和黏土含量呈显著正相关,均匀度指数(J)和4种常见种的数量与粉砂和黏土含量无显著相关,白氏文昌鱼(Branchiostoma belcheri)的栖息密度和生物量与粉砂和黏土含量呈显著负相关。上述结果证实,黏土含量增加到15%和粉砂含量增加到60%有利于多数大型底栖动物栖息密度和生物量的增加,但导致白氏文昌鱼栖息密度和生物量的减少,而红角沙蚕(Ceratonereiserythraeenis)、滑指矶沙蚕(Eunice indica)、光滑倍棘蛇尾(Amphioplus laevis)受底质细化的影响较小。  相似文献   

11.
Abstract. Coastal benthic communities in soft-bottom deposits of a restricted area were studied by seasonal sampling at nine stations. Faunal assemblages at three different depths were consistently different and exhibited a seasonal pattern of abundance and diversity. Multivariate statistical analyses suggest that each community structure is very similar during the three summer samplings; in autumn and winter many causes of disturbance can disrupt this structure, which is reconstituted the following summer. The stability of benthic communities in this physically variable environment is discussed and a "cyclic" adjustment mechanism of stability is proposed to explain the dynamics of the benthos in this area.  相似文献   

12.
The macrofauna communities on the Dogger Bank (North Sea) from the 1920s, the 1950s and the 1980s to the 2000s were compared and identified five communities with similar spatial distribution throughout the 20th century. The abundance of dominant species in the five communities varied with time. Most obvious in the 1950s was the loss of the extensive Spisula and Mactra patches, which covered most of the shallow parts of the Bank in the 1920s. Since the 1980s, they have been found only as juveniles. The biological regime shift in the late 1980s caused an increase in macrofauna abundance, species numbers, diversity and southern species in most of the communities. The climate regime shift in 2001 had opposite effects in which the abundance, species numbers, diversity and southern species decreased in most of the communities. The increase in interface-feeding species and the decrease in sand-licking amphipods in the 2000s especially in the shallow Bank Community give evidence for climate driven changes in water masses, currents, storms, turbidity and food availability via planktonic or benthic primary production. Both fishing impact and climate change are hypothesised as explaining the changes in the Dogger Bank macrofauna communities.  相似文献   

13.
The cruise conducted in the spring inter-monsoon (pre-monsoon) of April 2015 in the frame of a funded project epitomized an open ocean survey that allowed procuring a quasi-synoptic picture of cyclopoid copepod community structure in 18 open ocean stations of the Minicoy Island, Lakshadweep archipelago, off the southwestern Indian coast, based on the analysis of standing stock and composition in the integrated 0–10 m water column. The main objective was to explore the community structure of cyclopoid copepods prevailing here and which environmental variable influences the same. It is witnessed that sea surface temperature (SST) (30.42 ± 0.19°C), sea surface salinity (SSS) (33.56 ± 1.15 psu), and dissolved oxygen (DO) (4.32 ± 0.06 ml/L) with SSS and DO are the best matching variables diversifying cyclopoid copepod species (av. abundance 700 ± 386 no. of individuals/100 m3). Average zooplankton biomass (0.03 ml/m3) and abundance (8,989 ± 3,866 no. of individuals/100 m3) were also observed. Fifty-one cyclopoid copepod species belonging to four families and seven genera were identified, with the dominance of high saline species such as Sapphirina, Copilia, Farranula, and Oncaea. An abundance biomass curve (ABC) plot analysis indicated an undisturbed community with normal environmental conditions. TAXDTEST (taxonomic distinctness) depicted a diverse condition where all points clustered together within a 95% confidence level. Our results indicate that the cyclopoid copepod assemblage near Minicoy Island is a diverse, undisturbed community and hypothesize that the stable environmental conditions during pre-monsoon (spring inter-monsoon) preferred the diversification of cyclopoid copepods with the prevalence of high saline species. The data evolved could be used as a standard reference/benchmark to detect any deviation from an undisturbed/diverse community status of Minicoy Island in the looming scenario of climate change in and around the Indian Ocean.  相似文献   

14.
Macrobenthic infauna and associated environmental factors influencing the benthic community in the eastern coastal region of Shandong Peninsula were analyzed in four seasonal surveys from January 2007 to October 2007 (30 stations in winter, 20 stations in other three seasons), in order to understand the community structure and the factors unfluencing the benthic distribution. PRIMER 6.0 and SPSS 15.0 software packages were adopted to analyze the environmental and macrobenthic data. The results show that there were 260 macrobenthic species in total collected from the research region. The composition of species is:Polychaeta (94 species), Crustacea (75), Mollusca (56) and Echinoderm (12), among which, only 23 species were common species in the cruises of every season. The dominant species varied from season to season; however, the polychaete species Paralacydonia paradoxa Fauvel and Echinoderm species Amphioplus japonicus (Matsumoto) were always present year-round. The abundance and biomass of the macrobenthos in the research region were variable from season to season. The results of CLUSTER and MDS analysis show that the similarities of macrobenthic structures between the stations were low; most of the similarities were at about 30% of similarity value, only two stations were up to 70%. In accordance with the similarity values of the macrobenthic structures, we divided the 20 stations into five groups by arbitrary similarity level of 30%. The ABC curve indicates that the marcofauna communities in the research region had not been disturbed massively, except two stations, SB1 and SB3. Ecologically, benthos were controlled by a combination of factors such as salinity, phytoplankton, zooplankton, SiO3-Si and temperature, and no single factor could be considered as an ecological master factor.  相似文献   

15.
The ecology and diversity of the shallow soft‐bottom areas adjacent to coral reefs are still poorly known. To date, the few studies conducted in these habitats dealing with macroinvertebrate fauna have focused on their abundance spatial patterns at high taxonomic levels. Thus, some aspects important to evaluate the importance and vulnerability of these habitats, such as species diversity or the degree of habitat specialization, have often been overlooked. In this study we compared the crustacean assemblages present in four different habitats at Magoodhoo Island coral reef lagoon (Maldives): coral rubble, sandy areas and two different seagrass species (Thalassia hemprichii and Cymodocea sp.). Forty‐two different crustacean species belonging to 30 families and four orders were found. ‘Site’ was a significant factor in all of the statistical analyses, indicating that tropical soft‐bottom habitats can be highly heterogeneous, even at a spatial scale between tens and hundreds of meters. Although traditionally it has been considered that seagrass beds host greater species diversity and abundance of organisms than adjacent unvegetated habitats, no differences in the univariate measures of fauna (abundance of organisms, number of species and Shannon diversity) were observed among habitats. However, sandy areas, coral rubble and seagrass beds exhibited different species composition of crustacean communities. The percentage of taxa considered as potential habitat specialists was 27% and the number of species exclusively occurring in one habitat was especially high in seagrass beds. Thus, degradation of this vegetated habitat would result in a great loss of biodiversity in tropical shallow soft‐bottom habitats.  相似文献   

16.
Mapping surveys of coastal benthic habitat in Qeshm Island Geopark, Persian Gulf, were conducted using a combination of biological, sedimentological and echo‐sounding data. The survey area covered approximately 233 km2 in a depth range of 5–25 m, and the data were acquired from a single beam echo sounder, grab, video and still photography. Sediment and macrofauna samples were collected by grab at 76 stations and subjected to classification and ordination analyses. Two acoustic classes were identified differentiating along the near/offshore axis. Sediment texture was dominated by fine grain sizes, with five distinct sub‐sediment types. In total, 214 macrobenthic taxa were identified, of which polychaetes accounted for 60%. Other dominant groups included young sponges, nematodes, malacostracan crustacean, bivalves, ostracods and ophiuroids. Underwater videos and still photos integrated the macrofaunal and sedimentary data and revealed a range of biogenic sedimentary features such as burrows and tubes. The biological data identified six main biological assemblages showing an inshore/offshore pattern. The macrobenthic abundance did not demonstrate a significant difference with depth, although polychaetes were positively correlated with depth. The highest abundance and species richness were observed at median depths. Species distribution and diversity did not show any correlation with sediment type. A preliminary habitat mapping of the south coast of the Qeshm Island Geopark has been carried out, integrating acoustic, sediment and biological data.  相似文献   

17.
The study aims to compare the differences of macrofauna communities of wetlands at 3-year-forest- age, 5-year-forest-age Sonneratia apetala artificial mangroves, 5-year-forest-age Kandelia candel ar- tificial mangroves with the same restoration background, and the naked tidal flat in the Qi’ao Island Mangrove Nature Reserve of Zhuhai, Guangdong Province. The results show that there were signif- icant structural differences in macrofauna communities among four kinds of habitats. The increase of biomass and species diversity of macrofauna at 3-year-forest-age S. apetala artificial mangroves was obviously faster than that at 5-year-forest-age K. candel artificial mangroves whose average tree height was close to that of 3-year-forest-age S. apetala artificial mangroves. The BIOENV analysis shows that it was related to the rapid growth of S. apetala, which rapidly changed the light level and shading conditions in the forests. The 5-year-forest-age S. apetala artificial mangroves had lower macrofauna species diversity but higher density and biomass than K. candel artificial mangroves with the same forest age. This was due to the rapid changes of physical and chemical properties of habitat soil by the ecological restoration of S. apetala artificial mangroves as well as the changed food sources possibly caused by the leaf-litter of such non-indigenous mangrove species S. apetala. However, further survey should be conducted on whether there are any negative ecological impacts of large-scale cultivation of S. apetala on macrofauna communities, so as to evaluate correctly S. apetala’s role in the restoration of coastal mangrove ecosystems.  相似文献   

18.
Macrobenthic faunal composition, abundance, biomass and diversity together with a suite of sedimentary environmental parameters were investigated on a seasonal basis in order to determine factors regulating faunal distribution over the oligotrophic continental margin of the island of Crete (South Aegean Sea, North Eastern Mediterranean). Macrofaunal species composition was similar to that of the western Mediterranean and the neighboring Atlantic having several common dominant species. Mean benthic biomass, abundance and diversity decreased with depth, with a major transition zone occurring at 540 m, beyond which values declined sharply. At comparable depths biomass and abundance values were considerably lower to those found in the Atlantic, high-lighting the extreme oligotrophy of the area. The continental margin of Crete was characterised by a high diversity upper continental shelf environment (dominated by surface deposit feeding polychaetes) and a very low diversity slope and deep-basin environment (dominated by carnivorous and filter feeding polychaetes). Classification and ordination analyses revealed the existence of four principle clusters divided by a faunal boundary between 200 and 540 m, as well as beyond 940 m depth. Significant correlations between macrofauna and sediment parameters led to the conclusion that besides depth, food availability (as manifested by the concentration of chloroplastic pigments) is the principle regulating factor in the system. Such being the case, the prevailing hydrographic features that structure the pelagic food web and are directly responsible for the propagation of organic matter to the benthos also affect its community structure.  相似文献   

19.
浮游纤毛虫是真核微型生物的重要类群,在浮游生态系统中发挥着重要作用。利用传统形态学与高通量测序技术相结合的方法,于2020年9月至2021年8月对莱州湾三山岛近岸浮游纤毛虫进行每月两次的调查。对环境DNA的18S rRNA基因的V4区进行高通量测序,结果显示无壳寡毛类(占纤毛虫序列丰度的40.14%)和砂壳纤毛虫(10.67%)是优势类群,并且具有明显的季节变化。无壳寡毛类在冬季序列相对丰度最高,主要由急游虫属(Strombidium)和急游虫科未定类群(Strombidiidae_X)组成;砂壳类在春夏季序列相对丰度最高,主要由砂壳目未定类群(Tintinnida_XX)和拟铃虫属(Tintinnopsis)组成。浮游纤毛虫群落的β多样性呈现显著的季节变化,而α和β多样性在站点间差异均不显著。与环境因子的RDA分析显示,总有机碳和溶解氧含量是影响纤毛虫群落结构的主要环境驱动因子。形态学方法共检获鉴定17种纤毛虫,分别隶属于7个属,其中砂壳类在多样性和检获频率上均为最优势类群。研究填补了莱州湾三山岛海域浮游纤毛虫的多样性、群落结构和季节动态研究的空白,同时为深入研究温带海湾近岸浮游纤毛虫群落的长期变化规律以及对环境因子的响应机制提供本底资料。  相似文献   

20.
Abstract. The interrelationships between the main phytobenthic groups of Chlorophyceae, Phaeophyceae, and Rhodophyceae around Milos Island, Central Aegean Sea, were studied using standard ecological and mathematical methods. The analysis was based on seasonal sampling of 114 different macrophytobenthic species.
The employed ecological indices revealed that the sampling areas located on the north, south, and east side of Milos Island show similar annual fluctuations in abundance and species diversity. The resemblance was particularly high between all stations in October-February, between south and east stations during May, and between north and east stations during July.
Additionally, an annual cycle of group interaction with regard to species diversity and abundance exists between the Chlorophyceae, Rhodophyceae, and Phaeophyceae. The Rhodophyceae are the most abundant and dominant group throughout the year, showing percentages in the samples higher than 70% in all sampling areas.  相似文献   

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