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Relationship of species composition of tropical seagrass meadows to multiple physical environmental factors
Author(s) -
Tanaka Yoshiyuki,
Kayanne Hajime
Publication year - 2007
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/s11284-006-0189-3
Subject(s) - seagrass , transect , canonical correspondence analysis , detrended correspondence analysis , quadrat , silt , abundance (ecology) , intertidal zone , sediment , environmental science , ecology , relative species abundance , oceanography , geology , species richness , biology , ecosystem , geomorphology
The purpose of this study was to examine the relationship between species composition of tropical seagrasses and various physical environmental factors: depth, sediment thickness and silt–clay content in the sediments. We investigated species composition and abundance of seagrasses as well as the physical environmental factors for six transects around Ishigaki Island, southwest Japan. Eight species occurred in the quadrat census. The occurrence frequencies ranged from 66.8% ( Thalassia hemprichii ) to 4.5% (Enhalus acoroides ). Both canonical correspondence analysis (CCA) and cluster analysis elucidated that depth was mainly responsible for the distributions of species and assemblage type. Monte Carlo permutation for partial CCA revealed that 37.5% of the variance was explained by depth, 10.3% by sediment thickness and 4.6% by silt–clay content in the sediment. Twenty‐six sites were categorized into four assemblage types by a cluster analysis using the leaf area index (LAI; the ratio of total leaf area to bottom area) as a measure of species abundance. Type I was dominated by T . hemprichii and Cymodocea rotundata , Type II by C. serrulata , Type III by E . acoroides , and Type IV by Halodule pinifolia and Halophila ovalis . Type I occurred mostly in the intertidal zone (91.3±30.5 cm below MSL, mean sea level), Type II in the subtidal zone (179.1±75.0 cm below MSL) and Type IV in both shallow sites (between 47.8 and 75.6 cm below MSL) and in those with low silt–clay contents (between 2.0 and 3.8%).