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Ecology Of Macrobenthos In The Intertidal Area Of The Yangtze Estuary

Posted on:2013-11-16Degree:MasterType:Thesis
Country:ChinaCandidate:J YanFull Text:PDF
GTID:2230330392450147Subject:Aquatic biology
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The investigated of macrobenthos of Dongtan intertidal zones from2010Augustto2011May, have the distribution pattern of communities, secondary productivity andits important influence factors. The investigated of macrobenthos of intertidal zones ofJiuduan sand from May2011to November2011, in order to reseach impress of thehabitat, functional group to the macrobenthos communities. The results are as follows:1A total of83species were identified, mainly belonging to Crustacea, Annelida,Mollusca, insect and fishes. The mean abundance of the macrobenthos was637.83ind/m2,the mean biomass was37.30g/m2, the two items are the same to three sections,which was Dongwang sand(D)>Buyu por(tB)>Tuanjie sand(T), the mean abundancein seasons were summer> spring> autumn; the mean biomass was spring> summer>autumn。The mean diversity index of intertidal macrobenthic in Chong-ming Dongtan,e.g. Pielou index J, Simpson index D, Margalef index D were1.97,0.52,0.61and1.83.The mean diversity index of four ones is B>T> D. The MPI value between40.866and21.193, fluctuation is more acuteness, Dong-wang sand between14.352and5.948,autumn is clean, summer is moderately polluted; the MPI of Bu-yu port which between10.966and3.678is moderately polluted, the MPI of Tuan-jie sand from21.193to40.866, spring serious polluted, autumn is a few polluted, summer is clean. Dong-wangsand section is less affected by season, the macrobenthoc community composition isspecial in spring samples, all the samples are classified as a category; Bu-yu port andTuan-jie sand group gap varies by season, has obvious effect, spring and summer,autumn community community exists significant difference. The percentage ofsimilarity analysis of SIMPER display Stenothyra glabra, Corbicula fluminea,Assiminea, Assiminea latericea, Potamocorbula ustulata, Heteromastus filiformis are the significant species which important influence for the intertidal communitystructure.2The first result of Principal Components Analysis(PCA) was that Sal、TOC、NH4-N、NO2-N and TP were the critical factors due to differences environments.Combined with TN, TP and TDS sections, water quality of the intertidal zones overallpollution, show that intertidal overall pollution water quality; indicates that the waterquality was degrading along the intertidal zone from south to north.Mutidimensional-scale analysisi (MDS) and Cluster analysis indicated that themacrobenthos community structure of Bu-yu port and Tuan-jie sand were affected byseason, Dong-wang sand was little influence by season. Similarity SIMPER analysisshowed that the percentage of Corbicula fluminea, Stenothyra glabra, Assiminea sp,C.acherusicum, Heteromastus filiformis and son on (total number is twelve species)have the biggest impact on species for intertidal zones community structure.Relationship between environmental variables and the macrobenthos community wasstudies by using Canonical Correspondence Analysis(CCA) disclosed that TDS, C,TOC, Chla-O, Sal were the environment variables which significantly related tomacrobenthos community in spring of intertidal zones; in summer wereSal, C, TOC,TP, T, NO2-N, NO2-N+NO3-N; in autumn were NO2-N, Chla-W, T, TOC and TP.3The total mean abundance of the macrobenthos was637.83ind/m2,total meanbiomass in ash free dry mass (AFDW) was6.71g/m-2, total mean annual secondaryproductivity was6.91g m-2a-1, and total mean annual P/B value was1.01a-1. In threesections, the total mean density, biomass, secondary productivity, and P/B valueranking for Dong-wang sand>Bu-yu port>Tuan-jie sand. The secondary productivitywas mainly affected by Crustacea with six critical species, including Corbiculafluminea, Potamocorbula amurensis, Sinonovacula constricta, Stenothyra glabra,Bullacta exarata and Cerithidea sinensis, contributed65.24%of the total. The totalmean annual P/B value was1.01a-1, speculating that the average change ofmacrobenthos is year-generation and community structure is instability and obviouslyinfluenced by the environment. Analyzing the secondary productivity combination ofvariables, it was found that the secondary productivity is not only impacted by thebiomass and density but also the total Nitrogen and total Phosphorus of water.Relationship between environmental variables and the secondary productivity ofcommunity was studies by using CCA to determine which variables contribute most to differences in the secondary productivity of community. It discloses that Sal、TP、TOCand DO influenced the secondary productivity of Dong-wang sand macrobenthoscommunities; TN、TOC、Chla and DO influenced Buyu port; but Tuan-jie sand habitatremained the most stable condition, all the environmental variables of this researchchanges were minimal, presuming that the factors of its secondary productivity mayprefer to the physical factors of the deposition more.4Macrobenthos samples were collected from five habitat types, i.e.,Mudflat(mu),Scirpus mariqueter-triqueter(mt), Phragmites australis (pa), Spartina alterniflora(sa),Zizania latifolia (zl). A total of50species were identified, mainly belonging toCrustacea, Annelidas, Polychaeta, Insectand Fishes. Species number of Scirpusmariqueter-triqueter(mt) is the most second is Mudflat(mu)(26species), Phragmitesaustralis (pa) is22species, Zizania latifolia (zl) is21species, Spartina alterniflora(sa)is13species. The mean density of the macrobenthos was764.86ind/m2,the meanbiomass was68.12g/m2. The mean abundance of Annelida of the total percentage is80.82%, other is Crustacea> Insect> Polychaeta. The biomass of Crustacea in thetotal percentage is56.43%, other is Annelida> Insect> Polychaeta. The meanbiomass between spring and summer have very significant difference (P<0.01), themean abundance all have significant difference (P<0.05); the mean biomass betweensummer and autumn have very significant difference (P<0.01), but the mean biomassdifference is not significant (P>0.05); the mean biomass difference between spring andautumn is not significant (P=0.058), the mean abundance is very significant difference(P<0.01). Between five habitat types, the mean abundance is sa>mt>pa>mu>zl, themean biomass is zl>mt>pa>sa>mu. The mean abundance between mu and other fourtypes have significant difference (P<0.05); the mean biomass between zl and otherfour types have significant difference (P<0.05).The five types with four diversity index(d, H′, J, D), the lowest is sa, the biggest of d, H′is pa, J and D is zl type. Duncananalysis showed that D index in each habitat types had no significant difference (P>0.05), Shannon index H′and D index in Sa and zl type with significant differences(P<0.05), J index in Mu zone, sa type and zl type has significant difference (P<0.05).Community structure similarity analysis of five habitat types showed that mu and sahabitat types had most similar, followed by mt and pa habitat types, and zl with thebiggest difference. Diversity index shows that the pa type turn to terrestrial successionfeature is not apparent, Jiu-duan sand as new shoal wetland overall is still in the transitional stage, the work of protecting the extremely important.5There species can be divided into5categories according to the functional groupin first, last according to movement, feeding method of total, can be divided into11functional groups. The percentage of species in each functional groups from high tolow is PI>Ca=Ph>De>Om; the percentage of abundance in each functional groupsfrom high to low is Ph>PI>De>Ca>Om; the percentage of biomass in each functionalgroups from high to low is Ph>PI>De>Ca>Om. The number of species between thehigh tide zones and middle zones had significant difference (t=5.469, P<0.05), nosignificant difference excited between the forword two zones and the low tide zones,species number between seasonary had no significant difference (P>0.05). Using thetwo factor analysis of varionce to analysis the number of species, abundance, biomass,tidal zone, seasonary On nine Jiu-duan sand intertidal major functional groups, konwedthat the abundance of Ph functional groups in three tidal zones had significantdifference(P<0.05), the abundance of De functional groups had significant differencein seasonary(P<0.05); the biomass of PI, Ph had significant difference in tidezones(P<0.05), no significant difference in seasonary(P>0.05). The species number ofPh functional groups in tide zones had significant difference(P<0.05), PI functionalgroups in seasonary had very significant difference(P<0.01), De functional groups inseasonary had significant difference(P<0.05). Explain that the functional groupsdistribution of tide zones and seasonal effects are more obvious. The abundance ofDe functional groups had significant difference between spring and summer,autumn(P<0.05); no significant difference between summer and autumn(P>0.05); thespecies number had significant difference between spring and autumn(P<0.05).Analysis of the species number of PI in seasonal excited that summer and spring,autumn had significant difference(P<0.05). Community cluster analysis showed thatthe seasonal difference is small, tide groups had larger gap interval. SIMPER similarityanalysis of community structure, the results showed that HDX, FDX, FMX is theimportant groups which caused the differences between community. PCA analysisshowed that the high tide zones and the May-middle tidal zones influence HMX, CMJand CMX more greater than FMX and FDX, the summer, autumn-middle zonesinfluenced by FDX maximum; the low tide zones influence by FMX, CMX, CMJ.
Keywords/Search Tags:Changjiang Estuary, macrobenthos, impact factors, habitat types, functional groups, secondary production
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