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作 者 ：李旭林,彭逸生,万如,伍卡兰,陈桂珠*

期 刊 ：生态学报 2010年 30卷 14期 页码：3752~3759

关键词：相手蟹；红树植物；凋落叶；取食偏好性；单宁；C/N；

Keywords:sesarmid crabs, mangroves, leaf litter, food preference, tannin, C/N,

摘 要 ：大型底栖动物是红树林生态系统中重要的消费者，在红树林的营养物质转化和能量传递过程中具有重要作用。通过设置室内模拟饲喂实验，研究了华南沿海红树林大型底栖动物的常见种——无齿相手蟹（Sesarma dehaani）和双齿相手蟹（S. bidens）对外来红树植物无瓣海桑（Sonneratia apetala）和乡土红树植物秋茄（Kandelia obovata）、桐花树（Aegiceras corniculatum）凋落叶片的取食特性。结果表明，随着淋溶作用的进行，各树种叶片中单宁含量和C/N均逐渐降低，两个数值的变化幅度以秋茄叶片最大，分别达(45.85±7.74) g?kg-1和11.24%，无瓣海桑为(45.15±11.14) g?kg-1和2.43%，桐花树则为(18.75±1515) g?kg-1和-1.36%。随着叶片中单宁含量和C/N的降低，两种相手蟹的取食量相应地呈逐渐上升的趋势，双齿相手蟹从3097 g到10.079 g和无齿相手蟹则从2.480 g到8.723 g。两种相手蟹种间的取食特性差异不显著（P＞0.05），但对不同树种的取食上却存在显著差异，其中对桐花树的取食偏好性显著差于无瓣海桑和秋茄（P＜0.01），这主要与桐花树叶片的高单宁含量和低营养价值有关。研究结论说明大面积引种外来物种无瓣海桑将可能对华南沿海红树林生态系统的食物链结构产生潜在影响，并为红树林的生态恢复和科学造林提供了参考。

Abstract:The macrobenthos are the primary consumers in the mangrove ecosystem and play an important role on nutrient transformation and energy transportation. By conducting the indoor feeding experiment, the feeding characteristics of two common macrobenthos in the Southern China coastal region mangroves, Sesarma dehaani and S. bidens, to the leaf litter of the exotic mangrove species Sonneratia apetala, and two native species, Kandelia obovata and Aegiceras corniculatum were studied. The results showed that the leaf litter of Kandelia obovata had the greatest changes in Tannin content and C/N value during the leaching process, which decreased (45.85±7.74) g?kg-1 and 11.24%. Meanwhile, the decreasing rates of Tannin content and C/N value are (45.15±11.14) g?kg-1 and 2.43%, (18.75±15.15) g?kg-1 and -1.36% respectively for Sonneratia apetala and Aegiceras corniculatum. With the decrease of Tannin content and C/N value, the two Sesarmid crabs′ predation of leaves presented a slightly rising trend accordingly, which rised from 3.097 g to 10.079 g and 2.480 g to 8.723 g for Sesarma dehaani and S. bidens, respectively. In addition, there was no significant difference with the food preference between the two crabs (P<0.05), but there was significant difference between the three mangrove species. Both of the crabs were significantly prefer to Sonneratia apetala and Kandel obovata rather than Aegiceras corniculatum due to the high Tannin content and low nutritive value in the litter′s leaves (P<0.01). The results proved that introducing the exotic species Sonneratia. apetala at a large scale would incur the potential impact on the food chain structure in the Southern China coastal regeion mangroves, and also provided the reference for mangrove ecological restoration and reasonable afforestation.

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