射阳河口互花米草入侵对大型底栖动物群落的影响

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。     

互花米草扩张对江苏海滨湿地大型底栖动物的影响

2008年6月在苏北海滨湿地盐城珍禽国家级自然保护区内选取了3个典型断面8个样点,分析了大型底栖动物的种类、密度、生物量、多样性指数及均匀度指数等群落特征。本研究共采集到底栖动物21种,其中软体动物12种,占物种总数的57.1%;甲壳动物6种,占物种总数28.6%;环节动物2种,占物种总数9.5%;鱼类1种,占物种总数4.8%。结果显示:在光滩生境中,软体动物多以托氏昌螺(Umbonium thomasi)、泥螺(Bullacta exarata)及四角蛤蜊(Mactra veneriformis)为优势种,豆形拳蟹(Philyra pisum)亦有一定的数量。随着米草群落的侵入,软体动物中的尖锥拟蟹守螺(Cerithidea lar-gillierti)与环节动物中双齿围沙蚕(Perinereis aibuhitensis)则逐渐变成优势种。新生互花米草(Spartina alterniflora)群落提高了大型底栖动物的物种数量和丰富度,但随着时间的推移及米草的生长,米草群落中的底栖动物的物种数及多样性都会下降。可见,研究米草入侵对海滨湿地大型底栖动物群落的影响,除了调查方法及时空因素外,还应考虑到研究样地互花米草入侵时间的长短。     

黄河三角洲外来入侵物种米草对底泥微生物群落的影响

对黄河三角洲2个米草分布区及2个非米草分布区底泥中微生物生物量进行了测定,结果显示:大米草(S. anglica)分布区底泥中细菌、放线菌、真菌、反硝化细菌、硫酸盐还原细菌总数显著多于非米草分布区,米草的分布促进了底泥中微生物量的增加;互花米草(S. alterniflora)分布区的细菌、真菌总数多于大米草分布区,而其它微生物量则少于大米草分布区.     

米草属植物在中国海岸带的分布现状

结合遥感调查、现场定位,辅以文献检索、函调、电子邮件、电话等调查方式分析了4种米草属植物自引种以来在我国海岸带分布的历史及现状,结果表明,因人类围垦活动、大米草(Spartina anglica)的自身退化以及与互花米草存在生态位竞争关系,大米草在全国海岸带的分布面积不足16hm2,呈退化趋势。大绳草(Spartina cynosuriodes)尚未在实验地种植,狐米草(Spartina patens)仅在苏北、天津市的部分区域有少量种植。这两种米草没有对本土生态系统造成入侵威胁。互花米草(Spartina alterniflora)自1979年引种以来在全国海岸带被广泛种植,后经自然扩散,目前面积已达34451 hm2。结合我国的海岸带特征与互花米草的生态位,可以把其生长区域明显分为三部分:一是福建省福鼎市以南的海岸带滩涂,可能与红树林潜在的生态位竞争有关系;二是河口区域,如在长江口的崇明东滩,互花米草与本土植物表现出明显的竞争关系;三是在其他滩涂区域,该物种可能对本土生态系统造成一定程度的影响,在某些区域可能已经表现出一定的入侵性,但是其带来的促淤造陆、保滩护岸等巨大的生态效益也不应忽视。由于我国海岸带地质地貌类型复杂,互花米草在不同区域表现出不同的定植和扩散能力,与本土植被的竞争关系也明显不同。因此,在评价互花米草所造成的生态后果时,应从不同的角度出发进行全面、系统、客观、公正地评价。     

福建省罗源湾互花米草扩展过程及其特征分析

为探讨外来引种的互花米草（Spartina alterniflora Loisel）在我国海湾的扩展过程,根据1989-2010年遥感影像和野外观测数据,对罗源湾互花米草的分布特征进行分析,结果显示,对该区互花米草近20 a的扩展过程划分为3个阶段:前5 a其沿着高潮带平行于海岸线呈带状扩展;之后5 a在中潮带向湾内快速拓殖;后10 a则扩展缓慢,种群内部的空隙地逐渐被米草覆盖。截至2010年,罗源湾互花米草的总面积约为741.13 hm2。受潮滩环境分带性影响,罗源湾互花米草在高潮带平行于海岸线的扩展速度明显大于垂直于海岸线的扩展速度;在中潮带的快速扩展过程中互花米草倾向于先在潮沟两侧分布,这可能与归槽水和滩面摩阻作用有关,相比较,互花米草在浅洼地的扩展较滞后,该区域随着滩面的淤高过程逐渐被米草覆盖。在其整个扩展过程中,由于互花米草对潮流及悬浮颗粒的阻滞作用,使得其扩展前缘米草斑块和连续种群之间的光滩区成为悬浮颗粒及米草种子容易沉降的区域,互花米草易朝向该区域扩展。     

除草剂对滨海外来物种互化米草除控效果

互花米草(Spartina alterniflora)作为入侵物种,对我国沿海滩涂生态环境造成不利影响。为筛选成本低、见效快的互花米草化学除控剂,本研究选取了草甘膦、草铵膦2种除草剂,采用盆栽与大田试验探讨除草剂剂量及复配对互花米草的除控效果,通过底栖生物白蛤(Mactra veneriformis)和青蛤(Cyclina sinensis)培养模拟实验评价其生态安全性。结果表明,单一施用时草铵膦效果要优于草甘膦,最佳用量是药剂制造商推荐量的150%,但单一施用对互花米草致死率仅为20%;复配可以显著提高互花米草致死率、降低生物量,草甘膦、草铵膦复配处理的大田试验最佳用量为9450 mL/hm²、13500 mL/hm²,致死率可达90%。底栖生物培养试验结果表明,在所应用的剂量范围内,草甘膦和草铵膦对本土底栖生物致死率为0,在体内略有富集,但总体生态安全影响较小。本研究着重于滨海湿地互花米草的化学除控方式及生物安全性评价,以期为今后互花米草的除控研究提供参考。     

苏北滨海湿地互花米草两种繁殖体与本地种竞争能力分析

在碱蓬滩选取互花米草斑块,由外向内分为外围(A)、外侧(B)、内侧(C)、中心(D)四个取样点,研究互花米草实生苗、分蘖苗与本地植物碱蓬、芦苇的相对竞争力,探讨互花米草在碱蓬滩地入侵扩张的趋势。结果表明:1)在斑块B点处,互花米草实生苗与碱蓬相对竞争力高于互花米草分蘖苗与碱蓬相对竞争力;在斑块C点处,互花米草实生苗与碱蓬相对竞争力低于互花米草分蘖苗与碱蓬相对竞争力;多样性指数分析表现为:B点>C点>A点>D点;在互花米草斑块B点处重要值大小表现为:互花米草实生苗>碱蓬>芦苇实生苗>互花米草分蘖苗,在互花米草斑块C点处重要值大小表现为:互花米草分蘖苗>芦苇实生苗>互花米草实生苗>碱蓬。因此,碱蓬滩互花米草斑块主要是通过实生苗入侵新生境,向外扩张,通过互花米草分蘖苗维持种群的稳定。2)在斑块B点,芦苇实生苗与互花米草实生苗的相对竞争力相当,大于互花米草分蘖苗的相对竞争力,但在斑块C点处,互花米草分蘖苗高于芦苇实生苗。碱蓬与本地种芦苇也产生了竞争关系,并很有可能被芦苇和互花米草共同取代。3)互花米草实生苗与碱蓬的相对竞争力与滩涂微生境土壤含水量、土壤全盐量负相关(P<0.01),与土壤pH正相关(P<0.01);互花米草分蘖苗与碱蓬的相对竞争力与土壤含水量、土壤全盐量正相关(P<0.05),与土壤pH负相关(P<0.01)。碱蓬滩斑块处的含水量、盐度适合互花米草的定居、扩张。     

广西北海红树林宜林滩涂大型底栖动物群落结构特征

为了解广西北海红树林宜林滩涂大型底栖动物群落特征,本文首次在北海市选择了2条光滩断面、2条有少量互花米草分布的断面和2条被互花米草覆盖的断面开展生态调查,调查了大型底栖动物的群落结构特征,并分析了其与环境因子之间的关系。结果表明,调查区域大型底栖动物共29种,不同生境的软体动物生物量、节肢动物栖息密度及蟹洞数量差异显著(P<0.05),大型底栖动物的种类组成与沉积物的偏态显著正相关(P<0.05)。光滩样地黄金村HJ群落结构稳定,其余样地大型底栖动物的群落结构均不稳定。互花米草的生长会对大型底栖动物群落结构产生影响。     

海滩植被的生态意义及利用价值

在海滩生态系统中植物组成部分远比动物重要,因为植物是太阳能摄取者,是初级生产者,如果没有植物,一切动物都无法生存。世界著名生态学家 E.P.Odum 指出:在浅海区,特别是在淹露交替的潮间带,丰富的有机物质来源主要不是浮游植物而是高等植物。我国海滩自从六十年代成功地引种了大米草后,近几年又从美国引种三种米草植物(互花米草、狐米草和大绳草)。大米草经过二十余年的扩种繁殖,目前已在我国海滩     

闽江河口入侵植物互花米草对短叶茳芏的化感效应

外来植物入侵问题是当下生态安全和生物多样性的研究热点.研究其入侵机制对制定相应的防控措施具有重要意义.选用外来入侵种互花米草(Spartina alterniflora)的根、茎、叶3种构件,分别提取其水浸液为处理液(0.325 g/cm3),通过设置室内模拟实验,揭示其对闽江河口土著种短叶茳芏(Cyperus malaccensis)植株生长的影响.结果表明:互花米草的根、茎及叶浸提液对短叶茳芏的不同生长指标具有不同程度的化感作用.互花米草浸提液处理3个月后,根、茎及叶浸提液对短叶茳芏的分蘖数、叶面积均具有一定的抑制作用,但仅叶浸提液对分蘖数和叶面积的抑制作用分别达到显著水平和极显著水平,根及茎浸提液的抑制作用均不显著;茎浸提液对短叶茳芏的株高具有一定的促进作用,根及叶浸提液对短叶茳芏的株高具有一定的抑制作用,但三者的作用强度均未达到显著水平;根浸提液对短叶茳芏的根系活力具有轻微的促进作用,茎及叶浸提液对短叶茳芏的根系活力具有显著抑制作用;根、茎及叶浸提液对短叶茳芏的综合化感效应均表现为抑制作用,根与茎浸提液的综合化感效应相当,均小于叶浸提液的综合化感效应.     

Uptake and distribution of N, P and heavy metals in three dominant salt marsh macrophytes from Yangtze River estuary, China

We examined the variation in aboveground biomass accumulation and tissue concentrations of nitrogen (N), phosphorus (P), copper (Cu), zinc (Zn) and lead (Pb) in Phragmites australis (common reed), Spartina alterniflora (salt cordgrass), and Scirpus mariqueter throughout the growing season (April-October 2005), in order to determine the differences in net element accumulation and distribution between the three salt marsh macrophytes in the Yangtze River estuary, China. The aboveground biomass was significantly greater in the plots of S. alterniflora than in the plots of P. australis and S. mariqueter throughout the growing season (P<0.05). In August, the peak aboveground biomass was 1246+/-89 gDW/m(2), 2759+/-250 gDW/m(2) and 548+/-54 gDW/m(2) for P. australis, S. alterniflora and S. mariqueter, respectively. The concentrations of nutrients and heavy metals in plant tissues showed similar seasonal patterns. There was a steady decline in element concentrations of the aboveground tissues from April to October. Relative element concentrations in aboveground tissues were at a peak during the spring sampling intervals with minimum levels during the fall. But the concentrations of total nitrogen and total phosphorus in the belowground tissues were relatively constant throughout growing season. Generally, trace metal concentrations in the aboveground tissues of S. mariqueter was the highest throughout the growing season, and the metal concentrations of S. alterniflora tissues (aboveground and belowground) were greater than those of P. australis. Furthermore, the aboveground pools of nutrients and metals were consistently greater for S. alterniflora than for P. australis and S. mariqueter, which suggested that the rapid replacement of native P. australis and S. mariqueter with invasive S. alterniflora would significantly improve the magnitude of nutrient cycling and bioavailability of trace metals in the salt marsh and maybe transport more toxic metals into the water column and the detrital food web in the estuary.     

常见重金属在翅碱蓬(Suaeda heteroptera)根际沉积物系统季节迁移变化

应用原子吸收光谱法(AAS)和电感耦合等离子体原子发射光谱法(ICP-AES)对翅碱蓬-根际沉积物系统常见重金属(Cu、Pb、Zn和Cd)总量和不同化学形态含量进行了季节跟踪测定。结果表明,系统中Cu、Zn、Pb和Cd环境化学行为呈现显著季节变化。从化学形态上看,根际沉积物中Cu和Pb在生理周期内均以残渣态为主,有机结合态在夏季和秋季达较高值。Zn在生理周期内均以交换态为主且随季节变化明显,碳酸结合态和铁锰结合态随季节变化不明显。Cd以残渣态为主,交换态在春季达最高。从总量上看,根际沉积物中的Cu、Zn、Pb的总量在夏季和秋季具有较高值。从系统迁移情况看,植物对Cu和Pb吸收量均为冬季春季秋季夏季,且大部分限制于地下;其体内分布除秋季Pb为根叶茎外,其它时期均为根茎叶。Zn吸收量为秋季夏季冬季春季,且绝大部分被吸收至地上。Zn吸收和分布取决于根际沉积物生物有效含量;总之,春季植物体重金属向根际沉积物迁移。夏季和秋季,Cu、Pb和Cd由根际沉积物向植物体迁移变化并不明显,而Zn正好相反。4种元素在冬季均为根际沉积物向植物体内迁移。     

Phenolics and Proteins Affecting Palatability of Spartina Leaves to the Gastropod Littoraria irrorata

Along the southeastern coast of the United States, the saltmarsh periwinkle Littoraria irrorata is a major consumer of Spartina alterniflora . It prefers to feed on dead rather than living plants. During senescence and early decay, S. alterniflora leaves become colonized by fungi, their phenolic content declines, and their lipid content increases. In this study, the food preferences of L. irrorata were assessed by offering intact leaves or leaf powder suspended in agar. Relative palatabilities were determined by measuring the weight loss of intact leaves, or by estimating the area of feeding marks left on the surface of leaf powder suspensions. Both techniques demonstrated a clear preference for standing dead rather than yellow-green (senescent) leaves. Yellow-green leaves contained methanol-soluble feeding deterrents. A comparable deterrent effect could be achieved by adding ferulic acid, a phenolic compound common in yellow-green S. alterniflora , to leaf powder. The deterrent effects of methanol extracts or ferulic acid could be neutralized by simultaneously adding fungal mycelium or BSA. Littoraria irrorata preferred leaves colonized by fungi or bacteria over sterile leaves. When offered a choice of sterile leaves colonized by different fungi, the results were variable. In one experiment, L. irrorata clearly preferred one of three leaffungus combinations. The same preference was shown after the food items were treated with methanol/chloroform to remove lipids. In a second experiment with four other fungal strains, there was only a clear preference for one leaf-fungus combination after removal of lipids. The results suggest that the saltmarsh periwinkle prefers S. alterniflora leaves with low concentrations of phenolic deterrents, most likely ferulic acid, and with sufficient fungal biomass. The food choice may be influenced to a smaller degree by fungal components, which, depending on the species or strain, may be lipids or other compounds.     

互花米草入侵对潮滩生态系统服务功能的影响及其管理

在分析互花米草入侵我国沿海潮滩的基础上,论述了互花米草对潮滩生态系统生物量、生物多样性、潮滩水动力和沉积过程、土壤形成和营养物质积累、植被演替序列等生态服务功能的影响.并提出应根据不同区域的潮滩特征及其开发利用方向,因地制宜充分利用互花米草的正面价值,尽量减少其负面影响.     

栽培羊栖菜(Sargassum fusiforme)成熟藻体不同器官的组织结构显微观察及其生理生态学功能剖析

为全面了解栽培羊栖菜(Sargassum fusiforme)成熟藻体假根、茎、叶(气囊)和生殖托(雌托和雄托)四类器官的组织形态特征,运用石蜡切片法,对栽培羊栖菜成熟藻体各器官进行了组织形态学观察和讨论分析。结果表明,不同器官横切组织的形态、结构和宽度差异显著;假根,茎,叶,雌、雄生殖托的横切面由外向内分别为表皮、近表皮、皮层和髓部组织,而气囊无髓部组织结构,但具有内皮层。此外,雌、雄生殖托还包括生殖窝、卵和精子结构。栽培羊栖菜各器官表皮细胞均呈栅栏状排列,宽度顺序为:雄生殖托茎雌生殖托气囊叶假根;表皮和近表皮细胞含淀粉粒最多,内含色素体;皮层和髓部细胞的淀粉粒含量相对较少;皮层组织的细胞腔最大,具有典型植物细胞形态和发达的胞间隙;髓部细胞致密,细胞腔多数较小。有关文献报道表明,羊栖菜不同器官响应光照、水温、干出与沉水及低盐胁迫等环境信号表达的生理生态学特征差异显著。研究结果可为深度解析栽培羊栖菜各器官之间的亚细胞结构差异,不同器官生理代谢响应环境信号表达差异,不同器官组织对微量元素或重金属离子的吸收、转运和储藏机制分析等研究提供基础数据和理论参考。     

互花米草入侵对漳江口红树林保护区的影响研究

文章根据2019年、2020年漳江口红树林保护区内互花米草、沉积物、潮间带底栖生物的调查结果,结合历史遥感影像资料分析互花米草的入侵过程。结果表明：漳江口红树林保护区互花米草高潮区株高略低于同潮区红树植物,亦低于中潮区互花米草株高,更倾向于向光滩扩张;研究区域互花米草区沉积物中总氮、硫化物和有机碳含量高于光滩,全盐含量低于光滩;根据研究区域的遥感影像分析,2011—2019年漳江口互花米草保持较高的速率扩张,2020年互花米草扩张进入稳定期;根据丰度生物量比较法,2020年互花米草区的潮间带底栖生物群落结构较2019年稳定。在研究互花米草入侵对滨海湿地的影响时,除了考虑调查方法、时空因素和样地互花米草入侵时间的长短外,还应考虑互花米草入侵的不同扩张时期。     

Seasonal dynamics of Zostera noltii hornem. In the bay of arcachon (France)

Seasonal dynamics of Zostera noltii was studied during 1984 in Arcachon Bay, France. In this Bay, Z. noltii colonizes 70 km², i.e. approximately 50% of the total area, while Z. marina occupies only 4 km². Densities and length of vegetative and generative shoots and above-ground and below-ground biomasses were monitored in four meadows which differed according to their location in the Bay, tidal level and sediment composition. Three of these meadows were homogeneous, well-established beds whilst the fourth was under colonization and patchy. Shoot densities and maximal below-ground biomass were lower in the inner silty seagrass bed than in the sandy meadows located in the centre of the Bay. Maximal above-ground biomasses were similar in the two population types. In the well-established beds, vegetative shoot densities, above-ground and below-ground biomasses showed a unimodal pattern with minima in winter (4000 to 9000 shoots·m⁻², 40 to 80 g DW·m⁻², and 40 to 60 g DW·m⁻², respectively) and maxima in summer (11000 to 22000 shoots·m⁻², 110 to 150 g DW·m⁻², and 140 to 200 g DW·m⁻², respectively). Reproductive shoots were observed from the beginning of June until the end of September, except in the colonizing bed where they persisted until December. Furthermore, in the latter, maximal reproductive shoot density was higher (2600 shoots·m⁻²) than in the established beds (650 to 960 shoots·m⁻²). The total production of Z. noltii in Arcachon Bay was estimated to approximately 35.6·10⁶ kg DW·y⁻¹ (19.4·10⁶ kg DW·y⁻¹ for above-ground parts and 16.2·10⁶ kg DW·y⁻¹ for below-ground parts).     

Seasonal changes in the mesozooplankton biomass and community structure in subarctic and subtropical time-series stations in the western North Pacific

Seasonal changes in mesozooplankton biomass and their community structures were observed at time-series stations K2 (subarctic) and S1 (subtropical) in the western North Pacific Ocean. At K2, the maximum biomass was observed during the spring when primary productivity was still low. The annual mean biomasses in the euphotic and 200- to 1000-m layers were 1.39 (day) and 2.49 (night) g C m^?2 and 4.00 (day) and 3.63 (night) g C m^?2, respectively. Mesozooplankton vertical distribution was bimodal and mesopelagic peak was observed in a 200- to 300-m layer; it mainly comprised dormant copepods. Copepods predominated in most sampling layers, but euphausiids were dominant at the surface during the night. At S1, the maximum biomass was observed during the spring and the peak timing of biomass followed those of chlorophyll a and primary productivity. The annual mean biomasses in the euphotic and 200- to 1000-m layers were 0.10 (day) and 0.21 (night) g C m^?2 and 0.47 (day) and 0.26 (night) g C m^?2, respectively. Copepods were dominant in most sampling layers, but their mean proportion was lower than that in K2. Mesozooplankton community characteristics at both sites were compared with those at other time-series stations in the North Pacific and with each other. The annual mean primary productivities and sinking POC fluxes were equivalent at both sites; however, mesozooplankton biomasses were higher at K2 than at S1. The difference of biomasses was probably caused by differences of individual carbon losses, population turnover rates, and trophic structures of communities between the two sites.