Underground Vertical Distributions of Macrofauna and Root in a Mangrove Forest of Southern Thailand
Underground Vertical Distributions of Macrofauna and Root in a Mangrove Forest of Southern Thailand
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泰国南部红树林大型动物和根的地下垂直分布
DOI：
10.5134/176139
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
K. Ogino
中科院分区：
文献类型：
--
作者：
K. Wada;A. Komiyama;K. Ogino
在泰国南部的一个红树林中，研究了地下1 m深度的大型动物和根系生物量的垂直分布。小根分布较为均匀，大根则局限于较浅的土层。动物在较浅的地层中更为丰富，但也有一些能进入最深的地层。讨论了动物分布与大根分布的关系。世界各地已对红树林沼泽中大型底栖动物的沿岸和沿岸分布进行了定量研究（如Warner, 1969; Day, 1974; Sasekumar, 1974； Frith等，1976；Shokita等，1983;Shihe & Fuxue, 1985）。但目前还没有关于其地下垂直分布的定量资料。其中一个原因可能是红树林树根的缠结使其难以深入挖掘基质。在温带盐沼生境中，植物的根垫密度对招潮蟹的分布起着重要的控制作用（Ringold, 1979; Bertness & Miller, 1984）。同样，红树林的地下根系也被认为或多或少地影响着那里穴居动物的分布。本文报道了泰国南部红树林底栖大型动物的垂直分布与根系生物量的关系。研究地点和方法研究地点位于拉农（9°58'N, Publ）附近Hatsaikhao村的一片红树林中。Seto mar Biol。实验室。， 32(4/6), 329-333, 1987。（第12条）WADA， A. KOMIYAMA & K. OGINO, 98°38'E)，泰国南部。1982年12月，在离森林向海边缘约50米的地方建立了一块15米× 20米的地块。该地块在正常涨潮时未被淹没，基底为砂泥，局部有零星水坑。12月1日10时测得的水坑水温和盐度分别为27.0°C和27.28%0。该样地的优势树种为尖根霉，只有少量较小的木榄。林。和双歧杆菌（L.）布卢姆。树木最大直径为44.5 m，最高高度为37.2 m。基林面积为31.3 m2/ha，林分密度为733乔木。灌丛密度31500株/ha，基面积7.5 m2jha，平均直径2.4 em，平均高度3.1 min。在两棵直径分别为44.5米和43.6米的尖叶松（R. apiculata）大树之间的地块上布置了一条沟（0.2米× 15.5米）。壕沟地面上的支柱根/气团的新鲜重量总计63.8公斤。海沟地下水位28 ~ 30 em，地下水温度25.0°C，盐度22.98%a（12月9日10∶10）。沟槽被细分为31个隔室，每个隔室长0.5 m，每个隔室在垂直方向上进一步细分为10层土块，深度为1.0 m。310个土块，每个0.2米（宽）X 0.5米（长）X 0.1米（深），由手锯从光滑的壕沟壁上切割而成。每个土块用开口1毫米的网筛过，收集活根和动物。活根被分成八个直径级（50毫米），并称重新鲜。将动物固定在10%的海水福尔马林中，并记录每个土壤块中每个物种的个体数量。
In a mangrove forest of southern Thailand, underground vertical distributions of macrofauna and root biomass were investigated to a depth of 1 m. While smaller roots were distributed more or less evenly, larger roots were restricted to shallower layers. Animals were more abundant in shallower layers, but some of them penetrated into the deepest. Relation between the distribution of animals and that of larger roots is discussed. Cross-shore and for along-shore distributions of the benthic macrofauna in mangrove swamp have been studied quantitatively in various parts of the world (e.g. Warner, 1969; Day, 1974; Sasekumar, 1974; Frith et al., 1976; Shokita et al., 1983; Shihe & Fuxue, 1985). But the quantitative data on the underground vertical distribution of it have not so far been presented. One of the reason is probably that matted roots of mangrove trees make it difficult to dig the substrate deeper. In the temperate salt marsh habitat, the root mat density of the plants has been known to play an important role in controlling the distribution of fiddler crabs (Ringold, 1979; Bertness & Miller, 1984). Likewise, the underground root system of mangrove forest is assumed to influence more or less the distribution of the burrowing animals there. In this paper, we report the vertical distribution of benthic macrofauna in relation to the root biomass in a mangrove forest of southern Thailand. Study site and methods The study site was located in a mangrove forest at Hatsaikhao village near Ranong (9°58'N, Publ. Seto Mar. Biol. Lab., 32 (4/6), 329-333, 1987. (Article 12) 330 K. WADA, A. KOMIYAMA & K. OGINO 98°38'E), southern Thailand. In December 1982, a plot of 15m X 20m was established about 50 m landward from the seaward fringe of the forest. The plot area was not flooded at normal high tides and the substratum was sandy mud, with scattered puddles in places. The temperature and salinity of the water in a puddle measured at 10:00 on 1 Dec. were 27.0°C and 27.28%0, respectively. The dominant tree species in the plot was Rhizophora apiculata Blume with only a few smaller trees of Bruguiera gymnorrhiza (L.) Lam. and B. cylindrica (L.) Blume. The maximum diameter and height of the trees were 44.5 em and 37.2 m, respectively. The basal area totalled 31.3 m2/ha and the stand density was 733 treesjha. Shrub measurements were 31500/ha in the density, 7.5 m2jha in basal area, 2.4 em in mean diameter and 3.1 min mean height. A trench (0.2 m X 15.5 m) was laid out in the plot between two big trees of R. apiculata (diameter: 44.5 and 43.6 em). Fresh weight of prop roots/pneumatophores above the ground of the trench totalled 63.8 kg. The water table of the trench was 28-30 em deep and the temperature and salinity of the underground water were 25.0°C and 22.98%a, respectively (10: 10 on 9 Dec.). The trench was subdivided into 31 compartments, each 0.5 m long and each compartment was further subdivided vertically into 10 layers of soil blocks to a depth of 1.0 m. The 310 soil blocks, each 0.2 m (width) X 0.5 m (length) X 0.1 m (depth), were cut by a hand saw from the smoothed wall of the trench. Each soil block was sieved by a net with I mm opening to collect living roots and animals. Living roots were sorted into eight diameter classes ( 50 mm) and weighed fresh. Animals were fixed in 10% sea-water formalin and the number of individuals of each species was recorded for each soil block.