Accumulation and transport of seagrass-derived organic matter in reef flat sediment of Green Island, Great Barrier Reef
Accumulation and transport of seagrass-derived organic matter in reef flat sediment of Green Island, Great Barrier Reef
复制标题
大堡礁绿岛礁滩沉积物中海草源有机质的积累与迁移
DOI：
10.3354/meps175251
复制
发表时间：
1998
影响因子：
2.5
通讯作者：
H. Iizumi
中科院分区：
文献类型：
--
作者：
T. Miyajima;I. Koike;H. Yamano;H. Iizumi
与无植被的珊瑚礁沉积物相比，有海草植被的珊瑚礁沉积物通常富含有机质。对澳大利亚大堡礁（Great Barrier Reef）绿岛礁（Green Island Reef）有植被和无植被沉积物的组成和生物活性进行了比较研究。海草衍生的宏观碎片和无定形碎屑有机质是特别负责的海草床沉积物中的有机富集，而碳酸盐相关的，酸溶性有机质只是略有富集在海草床。沉积物捕集实验表明，被困在海草床的颗粒更丰富的有机碳比那些收集在无植被的地区，虽然有机碳通量取决于风的条件，而不是植被。被困的有机颗粒的C N：P比类似于沉积物有机物的无定形有机部分，显着富集N和P相比，海草衍生的，宏观有机碎片。植物源有机物的细菌分解过程中的氮和磷的保护可能是负责富集的N和P.的特征时间尺度的无定形有机物周转再悬浮和沉积估计是几十天或更少，相当于或更快矿化。这些比较表明，海草床有效地提高沉积存储的有机C，N和P，与营业额的有机池控制的物理过程，以及矿化。
Coral-reef sediment vegetated by seagrasses is usually enriched in organic matter as compared with unvegetated reef sediment. This study focused on comparisons of sediment composition and mob~lity between vegetated and unvegetated sediments of Green Island reef (the Great Barrier Reef, Australia). Seagrass-derived macroscopic debris and amorphous detrital organic matter were especially responsible for the organic enrichment in the seagrass-bed sediment, while carbonate-associated, acid-soluble organic matter was only slightly enriched in seagrass beds. A sediment-trap experiment revealed that particles trapped in the seagrass beds were richer in organic carbon than those collected in the unvegetated area, although the organic carbon flux depended on wind condition rather than vegetation. The trapped organic particles had C N:P ratios similar to the amorphous organic fraction of sediment organic matter, being significantly enriched in N and P as compared with seagrassderived, macroscopic organic fragments. Conservation of N and P during bacterial decomposition of plant-derived organic matter is probably responsible for the enrichment of N and P. The characteristic time scale of the amorphous organic matter turnover by resuspension and deposition was estimated to be tens of days or less, being comparable to or faster than mineralization. These comparisons suggest that seagrass beds effectively enhance sedimentary storage of organic C, N and P, with the turnover of the organic pools being controlled by physical processes as well as by mineralization.