| Summary: | 碩士 === 東海大學 === 環境科學系 === 84 === This study of polychaete worms on an intertidal flat of
Southern Tatu Estuary was conducted from November, 1994 to
September, 1995. Five core samples were taken bimonthly at each
of sixteen sites along four 1 km transects from high tide level
to mid-tide level. For one year of investigation, there were, at
least, about 27 species of polychaetes in the study area. Four
of these were excluded from analysis because of their sparsity.
Data for the other 23 species are analyzed through ANOVA,
Spearman rank correlation, PCA and canonical correlation
analysis to determine the spatial and temporal variation of the
whole polychaete community. The results indicate that:1. The
total species diversity and density in the mid-tide level where
the sediment is fine sand to median sand were far higher than in
the high tide level where the sediment is silt to very fine
sand.2. The spatial distribution pattern of the polychaete
communities is positively correlated with the mean particle
diameter of the substrate ( which is more important ) and
negatively correlated with the silt-clay content and sorting
coefficient ( which is less important).3. Armandia intermedia,
Tylonereis bogoyawleskyi, Glycera cf. tesselata, Scoloplos (S.)
tumidus and Scolelepis (S.) sp. were the larger dominant species
inhabiting the mid-tide level where the sediment is very fine
sand to median sand. At the high tide level where the sediment
is silt, Perinereis aibuhitensis, Neanthes glandicincta, Laonome
albicingillum and two unidentified species of Capitellidae
dominated.4. Species richness of all polychaetes in the study
area was highest in May, and Simpson''s indexes were higher from
March to May. This shows that the populations of the dominant
species decreased in abundance and the colonization of some
opportunistic species occured in the period.5. The populations
of most species showed significant seasonal fluctuation and were
most abundant in January and March, which indicates that the
breeding of most species occurs in autumn to spring.This study
concludes that the dominant polychaete species distributed at
different tide level may provide some part of the food resources
for the wintering and migrant shorebirds in this area. Because
of the diverse infauna flourishing in the mid-tide level with
fine sand sediment, this is the essential foraging ground for
the support of shorebirds in the whole reserve.
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