| Macrobenthos is an important part of tidal flat ecosystem. It accelerates the decomposition of debris underwater, regulates material exchange between mud and water, and accelerates self-purification of water。Macrobenthos is also an important part of food chains, which plays an important role on nutrient cycling and energy flowing. By studying benthic secondary productivity changes in different tidal flats, we can learn not only the effect of the different species and different functional groups in the energy flow, but also learn the character and seasonal changes of benthic secondary productivity in different tidal flats. The research has value on not only in the tidal flat ecosystem theoretical research, but also on development of tidal flat resources and conservation of biological diversityFrom July 2009 to May 2010, sampling was conducted at tidal flat of Tianhe Town, Wenzhou City, Zhejiang Province. We addressed the influence on macrobenthic secondary productivity in tidal flat ecosystem and discuss the spatial and seasonal changing laws of macrobenthic community and functional groups secondary productivity in different tidal flats. The main results are as follows:1. In total 31 species belonging to 19 Families,7 Phyla were found in the investigation. There were 4 species of Planktophagous group; they were Moerella iridescen, Potamocorbula ustulata, Assiminea brevicula and Sinonovacula constricta. There were 9 species of Phytophagous group, they were Cerithidea largillierti, Helice shen, Helice wuana, Sesarma haematocheir, Metaplax longipes, Metaplax sheni, Macrophthalmus japonicus, Uca arcuata and Ilyoplax sp. There were 9 species of Camivorous group; they were Nassariuss siquijorensis, Alpheus japonicus, Nemertean, Nephthys caeac, Glycera chirori, Neanthes japonica, Nereis japonica, Tylorrhynchus heterochaeta and Dipoaart ps. There were 7 species of Omnivorous group; they were Bullacta exarata, Philyra pisum, Philyra. Olivacea, Exopalaemon modestus, Scartelaos virid, Boleophthalmus pectinirostris and Rhniogobius pectinirostris. There are 2 species of Detritiv orous group; they were Phascolosoma esculenda and Eelworm.2. In different tidal flats, the biomass of macrobenthic community showed that: middle tidal flat>high tidal flat>low tidal flat. Within the same tidal flat, the biomass increased at first and then decreased as the distance from the coast adding. Biomass in different seasons showed that:spring>summer>autumn>winter in high tidal flat; spring >summer>winter>autumn in middle tidal flat; summer>autumn>spring> winter in low tidal flat. There was significant difference between macrobenthic biomass in different seasons; macrobenthic biomass was significantly affected by season.3. The biomass of different microbenthic functional groups showed that: Planktophagous>Omnivorous group>Phytophagous group>Carnivorous group> Detritivorous group; in different tidal flats, the biomass of microbenthic functional groups middle tidal flat>high tidal flat> low tidal flat. Within the same tidal flat, the biomass of microbenthic functional groups increased at first and then decreased as the distance from the coast adding. There was significant difference between microbenthic functional groups biomass in different seasons; microbenthic functional groups biomass was significantly affected by season.4. In different tidal flats, the energy of macrobenthic community showed that:middle tidal flat>high tidal flat>low tidal flat. Within the same tidal flat, the energy increased at first and then decreased as the distance from the coast adding. Energy in different seasons showed that:spring> summer>autumn>winter in high tidal flat; summer>autumn >spring>winter in middle tidal flat and low tidal flat. There was significant difference between macrobenthic energy in different seasons; macrobenthic energy was significantly affected by season. 5. The energy of different microbenthic functional groups showed that: Planktophagous>Omnivorous group>Phytophagous group>Carnivorous group> Detritivorous group; in different tidal flats, the energy of microbenthic functional groups showed that:middle tidal flat>high tidal flat> low tidal flat. Within the same tidal flat, the energy of microbenthic functional groups increased at first and then decreased as the distance from the coast adding. There was significant difference between microbenthic functional groups energy in different seasons; microbenthic functional groups energy was significantly affected by season.6. Clustering and sorting were used to analyzed macrobenthic biomass in different tidal flat, microbenthic functional groups biomass in different tidal flat, macrobenthic energy in different tidal flat, microbenthic functional groups energy in different tidal flat, sites were divided into 3 groups according to the tidal flat, the sites in the same group were similar and close to each other. Analysis shows that:season and tidal flat were two most important factors affecting the temporal and spatial variation of microbenthic secondary productivity. Because of these two kinds of factors, Tianhe initial flat microbenthic secondary productivity changed in a complex law.7. Macrobenthic average abundance was 583.58ind/m2 and macrobenthic average biomass was 6.75g (AFDW)/m2. It was calculated by Brey empirical formula that average secondary productivity is 7.71 g (A FDW)/(m2·a) and P/B value is 1.14. Secondary productivity of microbenthic community and microbenthic functional groups in high tidal flat was highest, the middle tidal flat with the second, low tidal flat with the lowest. Within the same tidal flat, the secondary productivity of microbenthic community and microbenthic functional groups increased at first and then decreased as the distance from the coast adding. Clustering and sorting were used to analyzed the secondary productivity of microbenthic community and microbenthic functional groups in different tidal flat, sites were divided into 3 groups according to the tidal flat, the sites in the same group were similar and close to each other. Comparing with the microbenthic secondary productivity of the other seas, analysis shows that:habitat was the most important factor affecting the variation of microbenthic secondary productivity. |
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