| Macrobenthos play an important role in the mudflat wetland ecological system as the intermediate link of the circulation of materials and the energy flow. Its distribution is not only closely related to hydrological and other physical and chemical environment of beach sediment, but also with different natural or man-made tinterference in different scales of time and space. The architectural feature of macrobenthic communities in different habitats reflect the characteristics of different ecological system.From November 2012 to July 2014, we made a study about the temporal and spatial variation of macrobenthos’biodiversities, functional groups, nutrition level, secondary productivity, etal. In annual January, April, July and November in Maoyan Island in Yuhuan County, Taizhou city, Zhejiang province, macrobenthic assemblages were investigated in artificial Kandelia obovata mangrove forests, bare mudflat and invation plant Spartina alterniflora. By the same way, we made a study of Xuanmen Bay wetland park’ macrobenthic communities in bare mudflat and invation plant Spartina alterniflora to compare the similarities and differences between the Maoyan Island and Xuanmen Bay wetland park, to provide scientific basis of the restrain the invasion of Spartina alterniflora and the protection of beach wetland resources.The main results were as follows:1. A total of 57 species were found in Maoyan Island, belonging to 34 families,9 classes, and 8 phyla. Annelidas, arthropods and mollusks contributed to the main component of macrobenthos, respectively accounting for 9.26%,46.30% and 35.19%. In the first year,57 species were found including 41 species in mangrove forest,35 species in Spartina alterniflora and 34 species in bare mudflat. In the second year,52 species were found including 47 species in mangrove forest,39 species in Spartina alterniflora and 37 species in bare mudflat. A total of 52 species including 37 species in Spartina alterniflora and 45 species in bare mudflat were found in Xuanmen Bay wetland park. The macrobenthos species in the second year in Maoyan Island had increased and were lower in autumn and winter than in spring and summer.2. The average annual density of different habitats in Maoyan Island had a law: bare mudflat(NB,194.88 ind·m-2)> mangrove forest(K,89.04 ind·m-2)>Spartina alterniflora(Sa,74.57 ind·m-2). The annual biomass also had a law:K(16.58 g·m-2)> Sa(14.16 g·m-2)> NB(9.97 g·m-2). Each site’s biomass showed very significant obviously difference in each site and obviously difference in each season. The biomass was obviously lower than other season and had a manifestation:the tidal power station’s each site’s biomass was lowest, the Hongtian village’s was in middle, the Nantan village’s was the highest. Different habitats’ biomass also showed obviously difference in each season and the lowest time was in winter. As a whole, the Nantan village’s density and biomass of macrobenthos were the highest in each site. Three different habitats’ macrobenthos’ density of the tidal power station and the Nantan village had obviously law. The highest annual average density was the Nantan village’s bare mudflat(NNB,216.75±181.84 ind·m-2), the lowest was the Hongtian village’s 6/7 years mangrove forest(HK6(7),37.44±8.31 ind·m-2). The highest annual average biomass was the Nantan village’s young mangrove forest(NKY,52.22±28.00 g·m-2), the lowest was the tidal power station’s Spartina alterniflora(DSa,5.44±2.68 g·m-2).3. The macrobenthos in different habitats in Maoyan Island had different results from traditional diversity and G-F diversity. Shannon-Weiner index H’had a law: mangrove forest(K)> Spartina alterniflora(Sa)>bare mudflat(NB), comparatively, K presented the most stable growth trend, and the index showed significant obviously difference in each habitat and season. NB had the highest simpson index D value and reach time was winter in the second year. The index showed negatively related to the pielou index J, NB’pielou index J was the lowest and the reach time was same with the former, they had obviously difference in each habitat and not in each season. K had the highest marglef index d which was characterized by gowth trend in the whole in three habitats and showed significant obviously different in each habitat and season. K and NB had the same change trend about G diversity, Sa was higher than the other in the beginning but turn lower by the time. K had the highest F diversity on the whole and only slightly lower in winter of the first year. Only pielou index J in each site had the least change by time, the highest value was in spring of the first year in HKY(2.35), Shannon-Weiner index H’in spring of the first year in KY6(7)(2.72), simpson index D in autumn of the first year in NKY(0.76), marglef index d in summer of the second year in HKY(5.16), the traditional diversity index’s highest value were all in sites respected K. The highest value of G index was in spring of the second year in NNB(3.12), F index in the same time in DSa(3.58), G-F index in the same time in DSa(0.16).G and F index showed significant obviously or obviously difference in each site and season, but G-F index not.4. The macrobenthos found in Maoyan Island could be divided into five functional groups. Planktophagous group including Assiminea sp., Retusa borneensis, Sinonovacula constricta clams and other arthropods, a few crustaceans such as Megabalanus sp., Corophium sinensis. Phytophagous group had the most species, including Cerithidea sp., Littoraria articulate, littorinopsis intermedia, Stenothyra glabra, Estellarca olivacea, Onchidium verruculatum and other arthropods, Uca sp., Ilyoplax sp., Macrophthalmus japonicus, Metaplax longipes, Helice wuana and other crustaceans. Carnivorous group had rich category including arthropods, crustaceans, annelidas and other animals, such as Lunatia gilva, Pachygrapsus crassipes, Scylla serrata, Ligia exotica, serpula, Glycera chirori, Nemertean, etal. Omnivorous group had Bullacta exarata, Alpheus sp., Exopalaemon modestus, periophthalmus, etal. Detritivorous group only had Phasolosma esculenta and Eelworm. In different habitats and sites, phytophagous group include the most species and had the highest percentage, detritivorous group only had two species and had the lowest percentage. In the first year, the functional composition of K and NB were similar, the carnivorous group percentage of Sa was obviously lower than the other. In the second year, the phytophagous group percentage of Sa was obviously higher than the other, but planktophagous group percentage was lower, carnivorous group percentage of K was the lowest, the other functional group percentage were similar. Each sites’ macrobenthos functional composition was different, but the common point was that phytophagous group had the highest percentage. Different nutrition levels of macrobenthos in species and density had a basic law in habitats or sites:the second nutrition level> the forth nutrition level> the third nutrition level. In the cluster and rank of two years’ macrobenthos functional group, DNB and NNB had the most stable performance.5. The secondary productivity of macrobenthos in Maoyan Island was affected by habitats and season and had a law:K> NB> Sa, summer> spring> autumn> winter(K and NB), autumn> spring> summer> winter(Sa), and the secondary productivity of macrobenthos reach the lowest in winter. From each sites’secondary productivity of macrobenthos, each site of Nantan village was higher than Hongtian village and tidal power station, NKY was the highest site and rech 30.69 g(AFDW)·m-2·a-1, its secondary productivity had the most change irrthe same season. The secondary productivity had not obviously difference in each habitat but had in each site, and was affected by season. NB had the highest P/B value, K and Sa were similar, DNB was the highest in sites. NB’ P/B value had larger variation in season, the sites in tidal power station and the NB of Nantan village were obviously higher than the other, and most sites’P/B value were higher in spring and winter than in summer and autumn. The P/B value of different habitats showed significant obviously difference and obviously difference in habitats and season, each site’s P/B showed significant obviously difference in each site and season.6. There were difference of macrobenthic communities in same habitats between Maoyan Island and Xuanmen Bay. Compared with Maoyan Island, Xuanmen Bay had another five species including Nassarius foveolatus, Cirsotrema perplexum, Siliqua minima, Metaplax shemi and Muraenesox cinereus, but had’t eleven species, and they had similar macrobenthos percentage in same habitats. Xuanmen Bay had specific dominant species including Lunatia gilva, Sinonovacula constricta and Ilyoplax serrata, Maoyan Island’specific dominant species including Cerithidea largillierti, Macrophthalmus japonicus, Uca arcuata, Sesarma haematocheir, Glycera chirori, Edwardsia sipunculoides and Nemertean. The desity of macrobenthos in Xuanmen Bay’s NB was obviously higher than sites in Maoyan Island, the biomass of sites in Sa of Xuanmen Bay was also outstanding compared with each site in Maoyan Island. The biodiversities of macrobenthos had obviously difference between NB and Sa, the Shannon-Weiner index H’ and Pielou index J of Sa were higher than NB, the Simpson index D and Marglef index d were lower, and the Marglef index d of Xuanmen Bay was higher than Maoyan Island. |
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