首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 296 毫秒
1.
Marine cave communities have been a continued source of ecological surprises, among other things because of their close ecological and evolutionary ties with the deep sea. The discovery of cladorhizid sponges, the deepest occurring poriferan family, in shallow Mediterranean caves in the 1990s was one such surprise, leading to the generally accepted hypothesis that the whole family was carnivorous, an unprecedented feeding mode for sponges. The recent observation of the cave species Asbestopluma hypogea in the Mediterranean bathyal, confirmed the view that some shallow caves can occasionally shelter otherwise deep‐dwelling species. Here we present new distribution data of A. hypogea, from deep Mediterranean locations, and for the first time from Atlantic locations. Among the new Atlantic records, the most surprising ones are located in three different geographic areas (Ria de Arousa, Groix Island and Cherbourg) of the NW European coasts, from the Iberian Peninsula to the English Channel, where A. hypogea reaches SCUBA depths (5–50 m), while not sheltered in marine caves. The carnivorous sponge however reaches its shallowest occurrence (5 m), in a small cave at Groix Island. The ecological significance of these discoveries, particularly the very patchy distribution and peculiar dynamics, are noteworthy, and the shallow occurrence of A. hypogea, together with other deep‐water or uncommon species, constitute unique assemblages that must be considered in conservation plans.  相似文献   

2.
Saltmarshes, seagrass meadows and mudflats are key habitats in estuarine ecosystems. Despite being involved in key ecological processes, the influence of different estuarine habitats on sediment bacterial communities remains understudied. Few studies have analysed and compared the bacterial communities of more than one estuarine habitat at different depths. Here, we investigated to what extent different habitats (mudflats; mono‐specific plots of seagrass [Zostera noltei] and two saltmarsh plants [Juncus maritimus and Spartina maritima]) and sampling depth (0, 5, 10 cm) influence variation in sediment bacterial composition. Our results showed significant differences in the abundance of selected higher taxa amongst habitats and depths. Surface sediment was characterized by bacteria assigned to the Acidimicrobiia, Flavobacteriia, Thiotrichales, Alteromonadales and Rhodobacterales, whereas in deeper sediment Deltaproteobacteria and Anaerolineae were dominant. Juncus sediment, in turn, presented the most distinct bacterial community, with Myxococcales abundant in this habitat. Sampling depth and habitat proved significant predictors of variation in sediment bacterial composition. The compositional dissimilarities amongst habitats and depths suggest functional divergence and complementarity, thus enhancing ecosystem functioning and health. Given the compositionally distinct communities found in different habitats and depths, our study corroborates the importance of conserving a diverse array of estuarine habitats.  相似文献   

3.
Western Pacific hydrothermal vents will soon be subjected to deep‐sea mining and peripheral sites are considered the most practical targets. The limited information on community dynamics and temporal change in these communities makes it difficult to anticipate the impact of mining activities and recovery trajectories. We studied community composition of peripheral communities along a cline in hydrothermal chemistry on the Eastern Lau Spreading Center and Valu Fa Ridge (ELSC‐VFR) and also studied patterns of temporal change. Peripheral communities located in the northern vent fields of the ELSC‐VFR are significantly different from those in the southern vent fields. Higher abundances of zoanthids and anemones were found in northern peripheral sites and the symbiont‐containing mussel Bathymodiolus brevior, brisingid seastars and polynoids were only present in the northern peripheral sites. By contrast, certain faunal groups were seen only in the southern peripheral sites, such as lollipop sponges, pycnogonids and ophiuroids. Taxonomic richness of the peripheral communities was similar to that of active vent communities, due to the presence of non‐vent endemic species that balanced the absence of species found in areas of active venting. The communities present at waning active sites resemble those of peripheral sites, indicating that peripheral species can colonize previously active vent sites in addition to settling in the periphery of areas of venting. Growth and mortality were observed in a number of the normally slow‐growing cladorhizid stick sponges, indicating that these animals may exhibit life history strategies in the vicinity of vents that differ from those previously recorded. A novel facultative association between polynoids and anemones is proposed based on their correlated distributions.  相似文献   

4.
Metazoan/microbial bioconstructions, or biostalactites (BSTs), discovered in submarine caves of Apulia c. 20 years ago—and later found in several shallow‐water Mediterranean caves—are receiving increasing attention in the last years. Examination of a single BST from the “lu Lampiùne” cave (Apulia), at the limit between the Adriatic and the Ionian seas, has been addressed for the first time in this paper. The BST started growing at c. 6,000 years ago with a rapid accretion of large‐sized serpulids (Protula), slowing down since about 3,000–4,000 years ago with a shift in main bioconstructors, probably caused by environmental changes. The present‐day community on the outer BST surface is dominated by skeletonised epibionts, mostly small‐sized serpulids, bryozoans and foraminifers, which contribute carbonate to the BST growth, by encrusting sponges, and by a few endobionts, including boring bivalves and insinuating sponges. New data remarkably increase biodiversity known for the “lu Lampiùne” cave and the cave habitat in the region. Thirty‐five taxa (16 bryozoans, 10 serpulids, 3 brachiopods, 2 foraminifers, 2 sponges, 1 bivalve and 1 cirriped) are recorded for the first time from Apulian marine caves, highlighting the need for further research in the area. In addition, the BST‐associated community seems to differ from those of individual BSTs from other Mediterranean caves, revealing the individuality of these communities.  相似文献   

5.
Microbial degradation and utilization of proteins derived from bacterial detritus were investigated in a microcosm experiment using Pseudomonas aeruginosa detritus as a substrate. To assess the effects of natural marine microbial communities on degradation and utilization of protein derived from P. aeruginosa cells, four microcosms were prepared: natural seawater (containing the natural microbial community) with P. aeruginosa detritus (N+Pa), autoclaved seawater with P. aeruginosa detritus (A+Pa), natural seawater (N) and autoclaved seawater (A) without adding anything as a control. The numbers of total and growing bacterial cells, protease activity, and transition of P. aeruginosa proteins were monitored in the four microcosms. Changes in the numbers of total and growing bacterial cells and protease activities indicated that bacterial detritus significantly stimulated the microbial community in the microcosms. Both the surviving P. aeruginosa in A+Pa and natural microbial community in N+Pa microcosms were able to degrade and utilize P. aeruginosa detritus; however, the community in N+Pa including various microbes maintained high activity longer, indicating that diversity is an important factor in keeping the community active. Even under the very high protease activity in N+Pa, 39-kDa and 48-kDa proteins from P. aeruginosa remained in the microcosm during the entire experiment (150 days). Immunoblotting suggested the 48-kDa protein was an intact molecule of OprP, which had been detected from the dissolved fraction of natural seawater in previous studies. This result suggests that the protein molecules that had been detected from natural seawater actually had a high tolerance to microbial degradation.  相似文献   

6.
  相似文献   

7.
Although continental shelf and slope environments typically exhibit high epifaunal biomass and have been subjected to increasing fishing pressure, ecological information on assemblages of non‐commercial invertebrate species from subtidal and bathyal areas remains limited. Sea stars (Echinodermata: Asteroidea), which are known to influence communities through their feeding habits, have received less attention than structural taxa such as corals and sponges. To better understand the ecological roles of asteroids on continental shelves, we investigated ~30 species and assessed their distributions and co‐occurrence with other benthic invertebrates on the shelf and slope of Eastern Canada. Using fisheries data and in situ video footage, we compiled a large dataset covering ~600,000 km2 that included over 350,000 individual asteroid records (37–2243 m depth). Multivariate analyses revealed geographically distinct asteroid assemblages, with a maximal overall density at 400–500 m and the highest diversity at 500–700 m. The most abundant and densely occurring species was Ctenodiscus crispatus. We found that asteroids associate with corals, sponges, bivalves, and other echinoderms, and that depth and substrate influence these assemblages. We identified species likely to affect coexisting organisms by their burrowing behavior that can disrupt epi‐ and infauna (C. crispatus) and through predation on ecologically important corals (Hippasteria phrygiana). In addition to providing baseline distribution and ecological information for many bathyal asteroid species in the Northwest Atlantic, this work highlights the abundance and diversified roles of asteroids within continental shelf and slope ecosystems.  相似文献   

8.
影响北欧海和楚科奇海夏季细菌丰度和生产力的因素   总被引：3，自引：0，他引：3  
Abundance and production of bacterioplankton were measured in the Nordic seas and Chukchi Sea during the5 th Chinese Arctic Research Expedition in summer 2012.The results showed that average bacterial abundances ranged from 3.31×10~(11) cells/m~3 to 2.25× 10~(11)cells/m~3,and average bacterial productions(calculated by carbon)were 0.46 mg/(m~3·d) and 0.54 mg/(m~3·d) in the Nordic seas and Chukchi Sea,respectively.T-test result showed that bacterial abundances were significantly different between the Nordic seas and Chukchi Sea,however,no significant difference was observed regarding bacterial productions.Based on the slope of lg bacterial biomass versus lg bacterial production,bacterial communities in the Nordic seas and Chukchi Sea were moderately dominated by bottom-up control.Both Pearson correlation analysis and multivariable linear regression indicated that temperature had significant positive correlation with bacterial abundance in the Chukchi Sea,while no correlations with productions in both areas.Meanwhile,Chl a had positive correlations with both bacterial abundance and production in these two regions.As the temperature and Chl a keep changing in the future,we suggest that both bacterial abundance and production been hanced in the Chukchi Sea but weaken in the Nordic seas,though the enhancement will not be dramatic as a result of higher pressure of predation and viral lysis.  相似文献   

9.

Since the discovery of hydrothermal vents in the late 1970s, deep-sea hydrothermal vent fields have attracted great attention as biological hotspots. However, compared with other ocean ridges, the structure and function of microbial communities inhabiting vent fields in the Central Indian ridge (CIR) remain understudied. Here, we provide for the first time 16S rRNA gene-based comparative metagenomic analysis of the sediment-associated microbial communities from three newly discovered vent fields in the CIR. Sediment samples collected in the Invent B, Invent E and Onnuri vent fields varied in geochemical properties, elemental concentrations and associated microbial communities. Proteobacteria (Gammaproteobacteria) was the dominant phylum in Invent B and Onnuri vent fields. In contrast, Invent E mainly consisted of Chloroflexi and Euryarchaeota. Predicted functional profiling revealed that the microbial communities in the three vents are dominated by chemoheterotrophic functions. In addition, microbial communities capable of respiration of sulfur compounds, nitrification, nitrite oxidation, methylotrophy, and methanotropy were found to be the main chemolithoautotrophs. Compared to other vent fields, Invent E showed a predominance of archaeal methanogens suggesting it exhibits slightly different geochemistry. Multivariate analysis indicated that the biogeochemical and trace metal differences are reflected in the sediment microbial compositions of the three vent fields. This study expands our current understanding of the microbial community structure and potential ecological functions of the newly discovered hydrothermal vent fields in the CIR.

  相似文献   

10.
Uncovering the role of environmental factors and finding critical factors which harbor significant fractions in governing microbial communities remain key questions in coastal marine systems. To detect the interactions between environmental factors and distributions of virio-and bacterioplankton in trophic coastal areas, we used flow cytometry to investigate the abundance of virio-and bacterioplankton covering 31 stations in the Bohai Sea of China. Our results suggested that the average abundance of total virus(TV) in winter(～2.29×10~8 particles/mL)was slightly lower than in summer(～3.83×10~8 particles/mL). The mean total bacterial abundance(TB) was much lower in winter(～2.54×107 particles/mL) than in summer(～5.43×10~7 particles/mL). Correlation analysis via redundancy analysis(RDA) and network analysis among virioplankton, bacterioplankton and environmental factors revealed that the abundances of viral and bacterial subpopulations depend on environmental factors. In winter, only temperature significantly influenced the abundances of virio-and bacterioplankton. In summer, in addition to temperature, both salinity and nutrient(SiO_2) had a remarkable impact on the distribution of virioand bacterioplankton. Our results showed a clear seasonal and trophic pattern throughout the whole water system, which revealed that temperature and eutrophication may play crucial roles in microbial distribution pattern.  相似文献   

11.
Eastern Pacific reefs are mostly made up of interlocking coral branches of Pocillopora, which are easily broken by physical forces associated with heavy swells and winds. In this study we investigated the potential of these coral fragments to enable propagation of boring sponges. For this, we quantified the frequency of occurrence and diversity of boring sponges in fragments of corals recently trapped among the branches of live colonies, and later tested the hypothesis that these sponges colonize new branches of corals. Nearly 80% of the coral colonies investigated had coral fragments among their branches, and 69% of these coral fragments contained boring sponges (11 species), some of these sponges in reproduction (23% of them carried oocytes). To test whether sponges inhabiting coral fragments could colonize new branching corals we transplanted them to healthy branches, and to branches whose living tissue was mechanically eliminated to simulate damage produced by grazing and death after bleaching and other causes of coral tissue mortality. All the transplanted coral fragments cemented to each new colony by means of calcification, and of the three sponge species tested (Cliona vermifera, Cliona tropicalis and Thoosa mismalolli) only C. vermifera was able to colonize both new living branches (26.9%) and cleaned branches (65.5%). The apparent capability of C. vermifera to colonize by direct contact may be another key ability of this species to maintain high frequency of occurrence in Pacific coral reefs. However, although C. tropicalis and T. mismalolli were not able to colonize new coral substrata by direct contact, coral fragments have the potential to contribute to local persistence of these sponges and to their dispersal, both by asexual (fragments) and sexual means (transport of sexual products). The present findings may partly explain the current increase of excavating sponges on deteriorating reefs with a large availability of dead branching corals.  相似文献   

12.
Biostalactites formed by metazoan–microbialite associations from three submerged marine caves in the Plemmirio Peninsula (south of Syracuse, Ionian Sea) are randomly distributed and show different sizes and morphologies, as well as variations in surface roughness/smoothness. The biostalactites consist of crusts a few centimeters thick of small serpulids and other metazoans, associated with fine‐grained carbonate; the larger ones often include a nucleus of serpulid tubes (Protula). The metazoans include mainly serpuloideans, sponges, bryozoans and foraminifers but microbial carbonates are also significant components. The composition of both the living communities and thanatocoenoses on the outer surfaces, as well as the composition and fabric of the internal framework, were analysed and used to reconstruct the history of the caves. All of the identified sessile faunas mainly consist of cryptic and sciaphilic dwellers that reflect cave conditions and their variations through time. The distribution pattern, composition and abundance of the present‐day dwellers largely depend on the degree of roughness of the biostalactite surfaces and their positions within the caves. It has been suggested that the Protula specimens in the nuclei represent pioneer populations that formed aggregates during the early cave colonization phase, in response to relatively high food supply from seawater inflow and intruding continental waters. By contrast, the outer metazoan–microbialite carbonates reflect more confined conditions in the caves caused by Holocene sea‐level rises. Hypotheses are proposed for biostalactite growth, taking into account information about the growth rates of some constituents, and evidence of dissolution effects. Similarities and differences between these biostalactites and other Holocene deposits previously described from submarine caves in the Mediterranean Sea and in tropical reefs are discussed.  相似文献   

13.
为分析凡纳滨对虾（Litopenaeus vannamei）海水养殖过程中水体细菌群落多样性变化,本研究采用Illumina测序技术对福建漳浦县凡纳滨对虾海水养殖中后期水体样品进行16S rRNA基因高通量测序,同时进行水质参数测定。结果表明,养殖过程中,氨氮（NH4+-N）、化学需氧量（COD）值波动较大,其他水质参数值波动较小。检测到的细菌种群归属于19个门、35个纲、80个目、135个科、254个属,说明该养殖水体中细菌群落具有高度的多样性。变形菌门和拟杆菌门是养殖期间主要优势类群,不同养殖时期细菌组成存在一定的波动,但没有明显的变化规律。蓝细菌在第67天、115天表现出高丰度,且其丰度在养殖期间变化较大（比例变化为0.7%~63.9%）。此外,益生菌和潜在致病菌丰度在养殖期间很低。冗余分析（Redundancy analysis,RDA）表明,对细菌群落影响最大的水质因子是化学需氧量与硝酸盐浓度比值（COD/NO3-）和COD;降低溶氧可以增加细菌丰富度。总之,本研究初步揭示了对虾养殖中后期水体微生物的演替规律,发现水质因子对养殖水体微生物组成具有显著影响,研究结果为凡纳滨对虾健康养殖提供一定的参考意义。  相似文献   

14.
Although environmental factors such as grain size and organic carbon content may influence the distribution of microbes in marine sediments, there has been little experimental study of the topic to date. To investigate how those sediment variables affect microbial colonisation under in situ conditions, deep‐sea sediments and artificial sediments (glass beads, sands) were incubated in the Arctic deep sea at 2500 m water depth with or without chitin, one of the most important carbon polymers in marine environments. Microbial abundance, biomass, chitobiase activity and changes in community structure were monitored after 7 days and 1 year. In control sediments without chitin addition, no significant changes in microbial abundance, biomass and activity were observed after 1 year. In the presence of chitin, however, considerable increases in these parameters were recorded in all three sediment types tested. Regardless of chitin addition, natural deep‐sea sediments were always associated with higher values of microbial abundance, biomass and activity compared with artificial sediments. Sediment type was always found to be the most significant factor explaining variation in enzymatic activity and bacterial community structure as compared to the effects of chitin amount, incubation time, and changes in cell number or biomass. Overall, this is the first in situ study that has addressed the effects of multiple factors and their interactions on abundance, biomass, activity and community structure of microbial communities in the deep Arctic Ocean.  相似文献   

15.
Bioeroding sponges belong to the most dominant bioeroders, significantly contributing to the erosion of coral reefs. Some species are tolerant or even benefit from environmental conditions such as ocean warming, acidification, and eutrophication. In consequence, increases in sponge bioerosion have been observed on some coral reefs over the last decades. The Abrolhos Bank is the largest coral reef system in the South Atlantic. It has been affected by sedimentation, eutrophication, overfishing, and climate change, mainly affecting coastal reefs, and at lesser intensity outer ones as well. This study aimed to describe spatial and temporal patterns in bioeroding sponge distribution in carbonate substrates in the Abrolhos Bank. Photo‐quadrats were used to compare bioeroding sponge abundance between two shallow reefs: a coastal, Pedra de Leste (PL), and an outer reef, Parcel dos Abrolhos (PAB). Each individual was delimitated over the substrate by determining the sponge surface through a line connecting the outermost papillae. The study was conducted over 6 years in 2008–2009 and 2013–2016. Four species of bioeroding sponges were identified: Cliona carteri Ridley, 1881, C. delitrix Pang, 1973, C. cf. schmidtii Ridley, 1881, and Siphonodictyon coralliphagum Rützler, 1971. The distribution and abundance of species varied between the inner and outer reefs and across the years, and displayed certain selectivity for the calcareous substrates recorded. Crustose coralline algae (CCA) were the main substrate excavated by the most abundant bioeroding species, C. carteri, and represented 70% of the substrate types occupied by this sponge (CCA, coral overgrown by CCA and plain coral). The highest abundance of bioeroding sponges observed in photo‐quadrats was 21.3 individuals/m2 at the outer reefs (PAB) in 2014. The abundances or areal extents of bioeroding sponges were up to 10 times greater on the outer reefs than on the coastal ones, where sedimentation is higher and more strongly influenced by siliciclastic material. Moreover, a higher herbivorous fish biomass has been reported on outer reefs which could also influence the higher abundance of bioeroding sponges in outer reefs. During the study period of 6 years, an increase in bioeroding sponge abundance was observed at the outer reefs (PAB), with the sea surface temperature increase. As CCA have an important role in reefal cementation and carbonate production in the Abrolhos reefs, a bioerosion impact might be expected, in particular, on the outer reefs.  相似文献   

16.
Interactions between microfouling components influence the biofilm community and the cascading events, thus playing an important role in the biofouling process. Bacteria and diatoms are among the dominant forms reported in biofilms. Experiments were carried out with natural marine biofilms from a tropical monsoon‐influenced environment to evaluate the interactions between bacteria and diatoms through application of antibiotics (streptomycin and chloramphenicol). Overall, chloramphenicol inhibited diatom communities, whereas streptomycin did not. These antibiotic‐mediated changes in the fouling diatom community were consistent across the seasons. However, the rates at which the fouling communities changed depended on the initial species composition. It was also observed that elevated nutrient concentrations overrode the inhibitory effect of chloramphenicol. Maximum Vibrio enhancement was observed in the enriched conditions during the pre‐monsoon and unenriched conditions during the monsoon (with naturally elevated background nutrient concentrations), highlighting the relevance of nutrient concentrations for Vibrio spp. This has interesting implications for antibiotic‐mediated interactions between fouling diatom and bacterial communities under differing nutrient regimes. Although this study indicates the relevance of ‘cross‐talk’ at the microfouling level, understanding the effects of additional microbial products (e.g. bacteriocins and peptidoglycan) on these community‐level interactions will represent a step forward.  相似文献   

17.
Sponges alter the proportion of structural and morphological components such as spicule skeleton and number of oscula in response to environment, development and growth. Such mechanisms indicate morphological and physiological variations within populations. We measured the pumping rate of different sized specimens of contractile sponge Cinachyrella cf. cavernosa present in the intertidal rock pools, during morning and afternoon low tides along the central west coast of India. Additionally, we measured the exhalant opening (oscular cross‐sectional area—OSA), tissue density, spicule skeleton weight and the abundance of choanocyte chambers to assess the morphological variations. Water temperature and sponge size showed a significant positive effect on pumping rate. OSA and the number of oscula increased with sponge size, but the sponge volume‐specific pumping rate did not increase (0.029 ± 0.020 ml/s ml‐1). Histological sections showed the abundance of chaonocyte chambers increased marginally with the sponge size, but the contraction state affected the count. Both tissue density and spicule skeleton weight were positively correlated with sponge size, particularly the increase in the size and number of spicule bundles radiating from the centre indicated a denser core in larger specimens. The subcortical lacunae and the peripheral choanosome with high abundance of canals appear to be the major volume reduction zones during contraction events. Our results indicate that the size and number of spicule bundles increase with sponge volume and the variation in temperature, contraction state, and size and number of oscula influence the pumping rate of C. cf. cavernosa.  相似文献   

18.
东印度洋细菌类群水平与垂直分布初探   总被引：1，自引：0，他引：1  
作为海洋食物网的重要组成部分,微生物在海洋的生物化学循环以及能量和元素流动中起着重要的作用。目前对东印度洋中微生物的种群结构和分布知之甚少。本研究运用分子生物学手段,包括多聚酶链式反应-变形梯度凝胶电泳(PCR-DGGE)技术和高通量测序技术,对东印度洋的赤道区域以及邻近的孟加拉湾区域水体中细菌的16S rRNA基因进行了探索。结果表明,Bacteroidetes, Proteobacteria (Alpha和Gamma类群), Actinobacteria, Cyanobacteria和Planctomycetes为研究区域微生物的主要类群。通过PCR-DGGE,发现微生物类群具有显著的水平分布模式;进一步的高通量测序的结果更加清晰的显示出细菌类群的垂直分布模式:相对其他两层,Cyanobacteria和Actinobacteria在25米水层出现更多;Bacteroidetes在25m和150m为主要类群,而在75m水层相对较少;Proteobacteria (主要为Alphaproteobacteria)类群在75m水层为优势类群。随着水层的加深,不同站位的细菌类群组成趋于一致。结果表明高通量测序能够把占据微小部分的微生物类群区分出来。本研究是针对东印度洋水体中细菌的水平和垂直分布以及多样性信息的首次报道,研究结果对于进一步发现潜在微生物功能类群以及探索这些微生物在东印度洋中的能量和物质循环中的作用有所帮助。  相似文献   

19.
Spatial distribution, diversity, and composition of bacterial communities within the shallow sub-seafloor at the deep-sea hydrothermal field of the Suiyo Seamount, Izu-Bonin Arc, Western Pacific Ocean, were investigated. Fluids were sampled from four boreholes in this area. Each borehole was located near or away from active vents, the distance ranging 2–40 m from active vents. In addition, fluids discharging from a natural vent and ambient seawater were sampled in this area. We extracted DNA from each sample, amplified bacterial 16S rRNA genes by PCR, cloned the PCR products and sequenced. The total number of clones analyzed was 348. Most of the detected phylotypes were affiliated with the phylum Proteobacteria, of which the detection frequency in each clone library ranged from 84.6% to 100%. The bacterial community diversity and composition were different between hydrothermal fluids and seawater, between fluids from the boreholes and the vent, and even among fluids from each borehole. The relative abundances of the phylotypes related to Thiomicrospira, Methylobacterium and Sphingomonas were significantly different among fluids from each borehole. The phylotypes related to Thiomicrospira and Alcanivorax were detected in all of the boreholes and vent samples. Our findings provide insights into bacterial communities in the shallow sub-seafloor environments at active deep-sea hydrothermal vent fields.  相似文献   

20.
The prokaryotic microbial communities in the sediments play crucial roles in the ecological functions of mangrove ecosystems. Therefore, the environmental factors that affect the structures of these prokaryotic microbial communities could indirectly participate in the regulation of mangrove functions, which is of great value for mangrove studies. The particle size (PS) of soils is recently demonstrated as a key environmental factor for shaping the microbial communities; however, this hypothesis has rarely been tested for mangrove environments. A case study of three tropical mangroves from Sanya, China was performed in this work to assess the influence of PS on the prokaryotic microbial community structures of bacteria, archaea, diazotrophs, and denitrifiers in the sediments. Results showed the variability in the spatial scale and the stability in the temporal scale for the prokaryotic communities, indicating that the tropical mangrove sediments could be a versatile but stable environment. Among the collected environmental factors, PS, salinity, and humidity had the greatest impacts, and PS mostly affected the structures of these prokaryotic communities based on its highest R2 values of canonical correspondence analysis, Mental test, and linear fitting (p≤0.05). Furthermore, PS was positively correlated with the diversity and abundance of diazotrophic communities and negatively correlated with the abundances of methanogenic communities including Methanobacteriaceae, Methanospirillaceae, Methanoregulaceae, and Methanosaetaceae. Former studies show the increasing trend of PS caused by the rise of sea level and the intensification of human activities. Therefore, our findings indicate that PS could be a potential intermediate that links climate change and human activities with the possible ecological function migration of mangroves; meanwhile, the increase of PS could in turn release the stress of these environmental changes by increasing the abundance and diversity of the diazotrophic community and decreasing the abundances of methanogens.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号