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1.
盐地碱蓬是黄河三角洲重要的先锋植物,抗盐能力强,分布范围广,对维持该地区生态系统稳定和演替发挥着重要作用。通过野外取样测定,研究了潮间带和潮上带盐地碱蓬种群的形态及生物量分配特征。在个体大小上,潮间带盐地碱蓬在株高和地径上显著低于潮上带盐地碱蓬;潮上带盐地碱蓬密集分布的株高高于散生分布,而生物量低于散生分布。在生物量分配特征上,潮间带盐地碱蓬Ⅰ以发展花、叶为主,潮上带盐地碱蓬Ⅱ的密集分布以优先发展茎为主,潮上带盐地碱蓬Ⅲ的散生分布以发展枝为主,属于种群发展的稳定阶段。因此,盐地碱蓬通过形态特征及生物量分配特征的调节,以适应潮间带和潮上带的不同生境特征,从而达到种群维持和土壤改良的目的。  相似文献   

2.
以独流减河河口及其潮上带区域的互花米草(Spartina alterniflora Loisel.)、芦苇[Phragmites australis (Cav.)Trin. ex Steud.]和盐地碱蓬[Suaeda salsa (Linn.) Pall.]群落为研究对象,探究该区域不同植物群落碳(C)、氮(N)、磷(P)、硫(S)化学计量学特征及其驱动因素.结果显示,互花米草和芦苇地上部分C含量显著高于盐地碱蓬,而根系中的C含量则反之,显示了植物不同的C分配策略. N、P主要分布在植物地上部分光合器官,N含量与全国湿地植物和全球植物的含量水平相当,但P含量显著高于全国湿地植物和全球植物的含量. S在芦苇和盐地碱蓬体内主要分布在地上部分,而互花米草的S则主要分布在根系中,这有利于互花米草拓展地下空间,从而加速其入侵.互花米草的C/P和芦苇的C/N均显著高于其他植物,说明前者具有较高的P利用效率,而后者的N利用效率较高.河口潮上带芦苇和盐地碱蓬叶片N/P分别为7.32和8.90,而潮间带互花米草叶片N/P为14.45,根据生长速率假说,认为生长速率并不是互花米草与芦苇和盐地碱蓬竞争的有效手段,而高的P利用效率为互花米草种群的扩张创造了条件.相关性分析表明,在独流减河河口地区土壤P和盐度是植物体内元素平衡和生态化学计量变化的重要影响因子.综上,天津独流减河河口湿地正经历着由N限制向P限制的转变,P元素在该区域植物生长和演替方面起着重要作用.(图5表2参36)  相似文献   

3.
江苏潮滩湿地不同生境互花米草形态与生物量分配特征   总被引:6,自引:1,他引:5  
通过对江苏潮滩湿地不同生境互花米草(Spartina alterniflora)种群生境特征、形态与生物量分配特征的分析,研究籽实成熟期互花米草形态与生物量分配特征及其影响因素.结果表明:(1)江苏潮滩湿地自海向陆不同生境间互花米草单株地上生物量、各形态指标、叶生物量比、繁殖分配Ⅰ和繁殖分配Ⅱ差异均显著(P<0.05),且与形态指标及其他生物量分配指标相比,繁殖分配的变异系数最大.(2)互花米草发生地米草生长时间最长,各形态指标(除种子数外)及单株地上生物量均最高;定居时间为1 a的米草各形态指标及单株地上生物量均最低.互花米草单株地上生物量及各形态指标分别与种群定居时间之间均呈正相关关系,其中单株地上生物量、茎长、叶长、叶宽、茎直径和种子数与种群定居时间均在α=0.01或α=0.05水平上呈显著正相关.(3)互花米草各形态指标(除种子数外)与土壤有机质、土壤总氮间均在α=0.01或α=0.05水平上呈显著正相关,土壤有机质与总氮是引起互花米草形态特征差异的重要因素.(4)互花米草各生物量分配指标与种群定居时间及土壤环境因子间在大多数情况下相关不显著,在特定的生境中互花米草特殊的生物量分配特征可能是其适应并成功入侵江苏潮滩湿地不同生境的重要原因之一.  相似文献   

4.
通过现场采集辽东湾双台子河口翅碱蓬(Suaeda salsa)光谱数据,收集标准样方(1 m×1 m)的翅碱蓬生物量(Biomass),建立相关植被指数与翅碱蓬生物量的遥感反演回归算法,发现辽宁双台子河口湿地翅碱蓬生物量与植被指数PVI、SAVI和MSAVI的相关系数R2较高,直线回归方程相关系数分别达到0.626、0.698和0.679。同时,利用得到的估算模型,结合1990—2005年的双台子河口的TM影像数据,反演该区域翅碱蓬分布面积和生物量。结果发现:辽东湾双台子河口湿地翅碱蓬面积变化呈先降后升的趋势。通过植被指数(NDVI、RVI、PVI和MSAVI)和生物量的算法反演,发现翅碱蓬生物量曲线与分布面积曲线的变化趋势一致。  相似文献   

5.
于5、8和10月对黄河口湿地典型断面盐碱植被群落进行3个航次的野外生态调查,研究了不同植被覆盖的湿地土壤氮素的时空分布特征及典型盐碱植物碱蓬和芦苇群落土壤氮素的根际效应,并基于线性模型的冗余分析(RDA)探讨土壤理化参数对氮素分布特征的影响.结果表明,黄河口湿地5月和10月土壤氮素含量高于8月,土壤氮素以有机氮为主,无机氮以铵态氮为主;总体上,表层土壤氮素含量芦苇碱蓬光滩,光滩土壤氮素含量低于碱蓬和芦苇群落土壤的30%—50%;光滩、碱蓬和芦苇群落剖面土壤总氮、有机氮和铵态氮在0—10 cm表层含量最高,随土壤深度其含量下降,硝态氮在土壤中呈现显著淋溶作用,其峰值出现在地下土壤层30 cm左右;碱蓬和芦苇群落根际土壤氮素含量均高于非根际土壤,且碱蓬根际土壤氮素含量显著高于芦苇根际土壤(P0.05).RDA分析结果表明,影响土壤氮素分布特征的主要理化参数是土壤有机碳含量和pH.植被种类影响黄河口湿地土壤氮素的累积,一般情况下土壤氮素的累积量呈现芦苇碱蓬光滩的特征,并具有明显的季节差异,相对芦苇群落,碱蓬在生长季节8月份根际土壤中积累更多的氮素.  相似文献   

6.
黄河三角洲自然湿地植被的特征及演化   总被引:6,自引:0,他引:6  
在群落样方调查基础上对黄河三角洲自然湿地植被进行了分类、分布及演化研究.研究表明,黄河三角洲滨海湿地的自然湿地植被有2个植被亚型、7个群系、51个群丛,分盐生植被、水生植被和湿生植被3类.盐生植被、水生植被和湿生植被分别包括10、19和22个群丛类型.盐生植被和湿生植被的面积各约23万hmz,各占自然湿地总面积的44.76%,水生植被约7.83万hm2,占自然湿地总面积的10.48%.湿地植被的分布受距海远近、黄河河道摆动和人类活动的制约,盐生植被主要分布在三角洲外缘潮间带滩涂和潮上带外缘的微斜平地,湿生植被、水生植被主要分布在潮上带中上部的微斜平地、黄河入海河道2侧及古河道、决口扇形地间的河间洼地.受三角洲新生湿地不断形成等自然因素的影响,湿地植被发生顺行演替;受海岸侵蚀、黄河断流、风暴潮等自然灾害及人类活动的影响,湿地植被发生逆行演替和次生演替.湿地植被的顺行演替和次生演替使自然湿地的生态环境功能增强,逆行演替使自然湿地的生态环境功能减弱.  相似文献   

7.
结缕草Zoysia japonica克隆植株的基本形态学单元是复合节间。分析复合节间组分关系,可以进一步揭示其形态可塑性的细微特征和资源传输与分配的差异,同时也可以为形态可塑性成因提供合理的生理生态学解释。本文对温室内、外两种环境条件下生长的结缕草克隆植株的复合节间组分进行测定和分析,结果表明:温室内、外植株主匍匐茎的长度和生物量的波动比一级分枝大,缩短节间长度比伸长节间长度稳定,但缩短节间生物量较伸长节间生物量变化幅度大。伸长、缩短节间长度、生物量分别与复合节序数呈二次函数关系。伸长、缩短节间生物量和分株生物量在一个生长季的生长方程亦均呈二次函数关系。主匍匐茎根数量、生物量随复合节数递增基本呈递增趋势。在两种环境下,A分株根数、生物量均大于B分株根数、生物量(在结缕草匍匐茎上,着生于每个复合节的基端和梢端缩短节间上的分株分别称为A、B分株),且差异明显。温室内植株,在分株发育形成后,伸长、缩短节间的长度、生物量分别与匍匐茎根、A分株根数、B分株根数、生物量间相关性显著,温室外的相关性格局较复杂,且总体显著性低于温室内。结缕草克隆植株基本形态结构单元的复合节上的各个组成部分之间存在的密切相关关系,是导致结缕草克隆植物形成形态可塑性的细微特征格局的主要原因。  相似文献   

8.
原油污染已经成为黄河三角洲滨海湿地生态系统退化的重要影响因素,开展植物修复关键技术的研究对于退化湿地生态治理和恢复具有重要意义。采用室外盆栽方式开展碱蓬(Suaedasalsa)修复原油污染试验,试验设计3个原油污染水平(2、4、6g?kg~(-1),分别对应低、中、高水平处理);以无碱蓬种植处理为对照,每个处理设置3个重复。以月为观测时间尺度,通过测定和分析碱蓬生理指标、根际土壤原油含量和微生物特征等,研究碱蓬对原油污染土壤的修复过程。结果如下:在3个石油污染浓度条件下,碱蓬均能萌发和生长,但是低污染水平处理的碱蓬株高、生物量及主根系长度明显高于其他处理。原油降解变化与碱蓬生长特征具有一致性,表现为碱蓬生长初期和后期降解效率较低,而快速生长期时降解效率高。低、中和高水平处理下碱蓬对原油的降解率分别为38.61%、47.54%和30.89%,其中对饱和烃的降解作用较大。碱蓬根际区为发生原油降解作用的主要区域,基于分子手段鉴定出根际附近的变形菌为丰度最高的优势降解菌群。通过一级衰减方程拟合降解曲线,得出碱蓬对3个污染水平原油的降解速率常数分别为0.19、0.12和0.11,表明碱蓬对低污染水平原油的降解效率高于其他处理。研究结果可为碱蓬修复原油污染土壤提供参考依据。  相似文献   

9.
选取盐城滨海湿地典型滩地(互花米草与碱蓬交错区、碱蓬滩)互花米草斑块,研究互花米草和本地种的生长特征、斑块微生境变化和互花米草与本地种的相对竞争力。结果表明:①和本地土著种碱蓬Suaeda salsa、芦苇Phragmites australis相比,入侵种互花米草Spartina alterniflora能更有效地改善微生境,其发达根系能够提高土壤含水量,互花米草的耐盐特性和泌盐作用能够使得互花米草在高盐度环境中生存,并有效的降低土壤盐度;②在互花米草与碱蓬交错区,从互花米草斑块边缘到中心,碱蓬的长势显著变弱,互花米草的长势显著增强,互花米草与碱蓬的相对竞争力为1.94±0.94,互花米草的竞争能力明显强于碱蓬;③在碱蓬滩,从互花米草斑块边缘到中心,碱蓬、芦苇的长势显著变弱,互花米草的长势显著增强,互花米草与碱蓬的相对竞争力为0.87±0.30,互花米草与碱蓬之间的竞争相对平衡;④因此,互花米草可能通过种间竞争不断侵蚀碱蓬生境,从而取代当地土著植被碱蓬和芦苇。  相似文献   

10.
围封对荒漠草原沙芦草种群构件生物量分配特性的影响   总被引:1,自引:0,他引:1  
以宁夏盐池县四墩子荒漠草原沙芦草(Agropyron mongolicum)为研究对象,通过对比研究围栏内外沙芦草种群各构件生物量、构件分配格局及其相关关系,试图揭示围栏封育对植物资源分配格局和生态策略的影响。结果表明,(1)围栏封育后,沙芦草种群的高度、丛幅、盖度以及株丛生物量显著提高,提高比例依次为78.96%(P=0.040)、63.50%(P=0.013)、50.89%(P=0.032)、205.38%(P=0.022),而密度无显著变化(P=0.330)。(2)围封对沙芦草种群各构件生物量具有显著影响,与围栏外相比,围栏内沙芦草种群根、叶、穗生物量显著提高,提高比例依次为183.52%(P=0.020)、334.09%(P=0.011)、381.25%(P=0.005);且围栏内外均表现为根生物量最大(围栏内为38.53 g,围栏外为13.59 g),穗生物量最小(围栏内为6.16 g,围栏外为1.28 g)。(3)围封后,沙芦草种群的生物量分配比发生了不同程度的变化。其中,生殖枝和叶的生物量分配比显著升高,分别升高了31.45%(P=0.020)和4.20%(P=0.000),而营养枝生物量分配比和根冠比显著降低,降低比例分别为281.62%(P=0.002)和13.33%(P=0.023)。(4)除营养枝生物量与丛幅间表现为显著负相关关系外(P=0.039),沙芦草种群各构件生物量间以及各构件生物量与株高、丛幅之间均存在显著或极显著正相关性。围栏封育对沙芦草种群构件生物量及其分配格局有显著的影响,说明围封是植物维持其种群持续更新能力和恢复其在群落中地位的重要措施之一。  相似文献   

11.
In this experimental study, we compared the embryonic respiration rate in air and water of six East African sesarmid species with intertidal, supratidal and arboreal habits, to highlight possible adaptations in embryonic metabolism to their different lifestyles. The embryos of all analysed crabs showed bimodal respiration, but we did not find a trend towards an enhanced embryonic oxygen uptake in air from the intertidal to the arboreal and supratidal species. However, the late-stage embryos of the most land-adapted species, Chiromantes spp., showed an enhanced metabolism when immersed in sea water that we interpreted as an adaptive recovery mechanism to cope with the storage of by-products due to marine-based metabolic pathways during long emersion periods. Thus, we showed that the embryos of land-adapted species, although still strongly water dependent, are well adapted to semi-terrestrial habitats and represent a minor limiting factor for females, which are not restricted in their emersion period by the oxygen requirements of their embryos.  相似文献   

12.
Genetic population structures along the Japanese coast, analyzed by sequence data from the mitochondrial DNA COI region, were determined for four intertidal brachyuran species in the superfamily Thoracotremata (Ocypode ceratophthalma, Gaetice depressus, Chiromantes dehaani and Deiratonotus japonicus), which were characterized by different habitat requirements. O. ceratophthalma (seashore; supratidal sand) and C. dehaani (estuarine; supratidal marsh) showed no significant genetic differentiation among Japanese populations. The Japanese populations of O. ceratophthalma, however, were found to genetically differentiated from the Philippine population. G. depressus (seashore; intertidal cobbles) exhibited significant genetic differentiation between the Amami-Ohshima population and other local populations. D. japonicus (estuarine; intertidal cobbles) showed significant genetic differentiation among many local populations separated by about 30–1,200 km. The different patterns of genetic population structure recorded for the four species, thus, do not simply correspond to habitat type.  相似文献   

13.
Genetic population structures along the Japanese coast, analyzed by sequence data from the mitochondrial DNA COI region, were determined for four intertidal brachyuran species in the superfamily Thoracotremata (Ocypode ceratophthalma, Gaetice depressus, Chiromantes dehaani and Deiratonotus japonicus), which were characterized by different habitat requirements. O. ceratophthalma (seashore; supratidal sand) and C. dehaani (estuarine; supratidal marsh) showed no significant genetic differentiation among Japanese populations. The Japanese populations of O. ceratophthalma, however, were found to genetically differentiated from the Philippine population. G. depressus (seashore; intertidal cobbles) exhibited significant genetic differentiation between the Amami-Ohshima population and other local populations. D. japonicus (estuarine; intertidal cobbles) showed significant genetic differentiation among many local populations separated by about 30–1,200 km. The different patterns of genetic population structure recorded for the four species, thus, do not simply correspond to habitat type. An erratum to this article can be found at  相似文献   

14.
Recent studies have emphasised that organisms can experience physiological stress well within their geographic range limits. Developing methods for mechanistically predicting the presence, absence and physiological performance of organisms is therefore important because of the ongoing effects of climate change. In this study, we merged a biophysical–ecological (BE) model that estimates the aquatic (high tide) and aerial (low tide) body temperatures of Mytilus galloprovincialis with a Dynamic Energy Budget (DEB) model to predict growth, reproduction and mortality of this Mediterranean mussel in both intertidal and subtidal environments. Using weather and chlorophyll-a data from three Mediterranean sites along the Italian coasts, we show that predictions of sublethal and lethal (acute) stress can potentially explain the observed distribution (both presence and absence) of mussels in the intertidal and subtidal zones, and the maximum size of animals in the subtidal zones. Importantly, our results suggest that different mechanisms limit the intertidal distribution of mussels, and that these mechanisms do not follow a simple latitudinal gradient. At the northernmost site (Palermo), M. galloprovincialis appears to be excluded from the intertidal zone due to persistent exposure to lethal aerial temperatures, whereas at the southernmost sites (Porto Empedocle and Lampedusa) sublethal stress is the most important driver of mussel intertidal distribution. Our predictions provide a set of hypotheses for future work on the role of climate change in limiting intertidal distribution of mussels in the Mediterranean.  相似文献   

15.
选择北部湾9个典型采样点,研究了潮间带沉积物中重金属和多氯联苯(PCBs)的分布特征和生态风险.分析结果表明,Hg、As、Cu、Pb、Zn、Cd、Cr等重金属和总PCBs的平均含量分别为0.100、10.00、19.89、45.97、208.65、0.098、17.86 mg.kg-1和1.48!g.kg-1.重金属和PCBs表现出不同的空间变化规律.相关性分析表明,北部湾潮间带的重金属主要来自人为污染;沉积物的粒度参数和有机质含量等性质特征是影响PCBs分布和迁移的重要因素;重金属和PCBs总量之间不存在明显的相关性.生态风险评价结果表明,PCBs和Cd是北部湾潮间带最主要的生态风险因子,Zn和PCBs是优势污染物;研究区域总体处于中等生态风险等级,表明沿岸港口和临海工业等人为活动已经对北部湾滨海地区造成了一定的环境压力.  相似文献   

16.
In Deception Bay, northern Australia, during 1979–1981, a study was made of the distribution of Scylla serrata (Forskal) in an area having a broad intertidal zone. Juveniles (20 to 99 mm carapace width) were resident in the mangrove zone, remaining there during low tide. The majority of subadult crabs (100 to 149 mm) migrated into the intertidal zone to feed at high tide and retreated to subtidal waters at low tide. Adults (150 mm and larger) were caught mainly subtidally and only small numbers were captured in the intertidal at high tide. Few crabs were captured in the coolest months (May to August). Adults were captured on the flats mainly in the warmest months (January to April), but subadults could be captured over the entire summer (September to March). Juveniles were found in the upper intertidal throughout the year.  相似文献   

17.
Water movement is probably the most important factor influencing life in the interstices of sandy beaches. In order to better understand this ecosystem, e.g. the distribution and migration of interstitial fauna and overall energy transfer, measurements of water flow through high energy beaches were made on the Atlantic coast of the USA. Special hot thermistor-probes and associated electronic circuits were built, capable of measuring water-flow velocity down to less than 10 m/sec. These were buried in the sand at various depths and locations in the intertidal zone and the flow velocity recorded continuously for one or more tidal cycles. In addition, an orientation sensor was constructed and used together with the flow probe so that a picture of the flow patterns in the intertidal zone of a beach and their changes during a tidal pattern could be developed and defined quantitatively.  相似文献   

18.
R. Einav  S. Beer 《Marine Biology》1993,117(1):133-138
In this work, we investigated photosynthetic gas exchange responses of the red alga Acanthophora najadiformis (collected in 1991 from a shore near Netanya, Israel) to heating, light, inorganic carbon and desiccation of the thalli. This was done to elucidate some of the contributing causes for its particular restricted vertical distribution within the lower intertidal zone of the Israeli Mediterranean rocky shore. In contrast to other common intertidal species, the photosynthetic performance of A. najadiformis was very sensitive to desiccation and to high temperature, and these factors may thus prevent the alga from growing above the surge zone. On the other hand, this species photosynthesized five times faster in air than in water (provided it was kept highly hydrated), and this may be the reason why it does not succeed in competing with other algae in the subtidal which use HCO 3 - more efficiently.This paper is in partial fulfillment of a Ph.D. study by R. Einav in cooperation with the Department of Ecology, University of Bielefeld (under supervision of Prof. Dr. S. W. Breckle), under a cooperative arrangement between Tel Aviv and Bielefeld Universities  相似文献   

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