Sediment deposition and production in SE-Asia seagrass meadows
Sediment deposition and production in SE-Asia seagrass meadows
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DOI：
10.1016/s0272-7714(02)00286-x
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发表时间：
2003-04-01
影响因子：
2.8
通讯作者：
Tri, NH
中科院分区：
文献类型：
--
作者：
Gacia, E;Duarte, CM;Tri, NH
海草草甸对海岸沉积物中颗粒的捕获和结合起着重要的作用。然而，海草也可以通过碎屑的沉积和相关矿物颗粒的沉积，直接促进沉积物的产生。本研究旨在估计不同海草种类在广泛的沉积过程中对无机（碳酸盐和非碳酸盐）和有机沉积的贡献。沉积物捕集器测量的总日沉积量从菲律宾Silaqui的18.8 (+/-2.0)g DW m(-2) d（-1）到越南Bay Tien的681.1 (+/-102)g DW m(-2) d（-1）不等。这些测量结果对应于一次采样事件，代表了东南亚沿海地区旱季的沉积条件。acoroides是在所调查的海草草甸中最常见的物种，与Thalassia hemprichii一起出现在沉积物从低到非常高的地点。在低至中等沉积的地点存在Halodule uninervis和Cymodocea种。海草叶片的矿物质负荷随年龄增长而增加，其中，由于叶片最大且寿命较长，acoroides叶片的矿物质负荷较高（可达417 mg碳酸钙/叶和507 mg非碳酸盐矿物/叶），而由于叶片较短，海草叶片的矿物质负荷较低（4mg碳酸钙/叶和2 mg非碳酸盐矿物/叶）。在东南亚海草草甸中，非碳酸盐矿物的积累速度比附生群落生产碳酸钙的速度慢，因此由完全生长的叶片支撑的最终负荷平均低于碳酸钙负荷。我们的研究结果表明，在采样期间，东南亚海草的有机和无机产量占每天水柱沉积物质的一小部分（最多占15%）。在沉积通量较低的地区，碳酸盐组分的贡献可能是局部显著的（例如在西拉基占34%），但贡献较小(
Seagrass meadows play an important role in the trapping and binding of particles in coastal sediments. Yet seagrass may also contribute to sediment production directly, through the deposition of detritus and also the deposition of the associated mineral particles. This study aims at estimating the contribution of different seagrass species growing across an extensive range of deposition to inorganic (carbonate and non-carbonate) and organic sediment production. Total daily deposition measured with sediment traps varied from 18.8 (+/-2.0)g DW m(-2) d(-1) in Silaqui (Philippines) to 681.1 (+/-102)g DW m(-2) d(-1) in Bay Tien (Vietnam). These measurements correspond to a single sampling event and represent sedimentation conditions during the dry season in SE-Asia coastal areas. Enhalus acoroides was the most common species in the seagrass meadows visited and, together with Thalassia hemprichii, was present at sites from low to very high deposition. Halodule uninervis and Cymodocea species were present in sites from low to medium deposition. The mineral load in seagrass leaves increased with age, and was high in E. acoroides because it had the largest and long-lived leaves (up to 417 mg calcium carbonate per leaf and 507 mg non-carbonate minerals per leaf) and low in H. uninervis with short-lived leaves (4 mg calcium carbonate per leaf and 2 mg non-carbonate minerals per leaf). In SE-Asia seagrass meadows non-carbonate minerals accumulate at slower rates than the production of calcium carbonate by the epiphytic community, consequently the final loads supported by fully grown leaves were, as average, lower than calcium carbonate loads. Our results show that organic and inorganic production of the seagrasses in SE-Asia represents a small contribution (maximum of 15%) of the materials sedimented on a daily base by the water column during the sampling period. The contribution of the carbonate fraction can be locally significant (i.e. 34% in Silaqui) in areas where the depositional flux is low, but is minor (