Impact of different benthic animals on phosphorus dynamics across the sediment-water interface.
Impact of different benthic animals on phosphorus dynamics across the sediment-water interface.
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DOI：
10.1016/s1001-0742(09)60305-3
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发表时间：
2010-11
影响因子：
6.9
通讯作者：
Lei Zhang;Xiao-zhi Gu;Chengxin Fanl;J. Shang;Qiushi Shen;Zhaode Wang;Ji Shen
中科院分区：
文献类型：
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作者：
Lei Zhang;Xiao-zhi Gu;Chengxin Fanl;J. Shang;Qiushi Shen;Zhaode Wang;Ji Shen
生物扰动作用作为成岩作用的一种，影响着沉积物-水界面的溶质交换。不同的底栖动物在沉积物中的机械活动不同，因此它们可能对跨SWI的溶质交换产生不同的影响。这项实验室研究探讨了不同的底栖动物对整个SWI磷动态的影响。介绍了水蠕虫和摇蚊幼虫作为模式生物，根据它们的机械活动，它们分别属于向上输送者和廊道扩散者。采用连续流动培养系统对太湖的沉积物、水体、蠕虫和幼虫进行了微宇宙模拟研究。为了比较它们的生物扰动效果，对蠕虫和幼虫采用相同的生物量（17.1g湿重（ww）/m2）。蠕虫对沉积物中氧气渗透深度无影响，而幼虫对沉积物中氧气渗透深度有增加作用。它们的出现也增强了沉积物的O2吸收。孔隙水中的亚铁氧化生成三价铁羟基氧化物，吸附上覆水和孔隙水中的可溶性活性磷。蚯蚓在沉积物中形成了直径约2 mm、最大长度约6 cm的氧化管，并显著降低了孔隙水中的亚铁和SRP。蠕虫建造没有视觉氧化画廊在沉积物中的幼虫相比，他们没有显着改变SRP在孔隙水相对于对照治疗。蠕虫和幼虫对SRP的吸附抑制了沉积物中SRP的释放。相比之下，蠕虫抑制更多的SRP释放比幼虫基于相同的生物量，因为他们相继更新的三价铁羟基氧化物丰富的氧化层，通过他们的沉积。
As a diagenetic progress, bioturbation influences solute exchange across the sediment-water interface (SWI). Different benthic animals have various mechanical activities in sediment, thereby they may have different effects on solute exchange across the SWI. This laboratory study examined the impacts of different benthic animals on phosphorus dynamics across the SWI. Tubificid worms and Chironomidae larvae were introduced as model organisms which, based on their mechanical activities, belong to upward-conveyors and gallery-diffusers, respectively. The microcosm simulation study was carried out with a continuous flow culture system, and all sediment, water, and worms and larvae specimens were sampled from Taihu Lake, China. To compare their bioturbation effects, the same biomass (17.1 g wet weight (ww)/m2) was adopted for worms and larvae. Worms altered no oxygen penetration depth in sediment, while larvae increased the O2penetration depth, compared to the control treatment. Their emergence also enhanced sediment O2uptake. The oxidation of ferrous iron in pore water produced ferric iron oxyhydroxides that adsorbed soluble reactive phosphorus (SRP) from the overlying water and pore water. Larvae built obviously oxidized tubes with about 2 mm diameter and the maximum length of 6 cm in sediment, and significantly decreased ferrous iron and SRP in the pore water compared to the control and worms treatments. Worms constructed no visually-oxidized galleries in the sediment in contrast to larvae, and they did not significantly alter SRP in the pore water relative to the control treatment. The adsorption of ferric iron oxyhydroxides to SRP caused by worms and larvae inhibited SRP release from sediment. Comparatively, worms inhibited more SRP release than larvae based on the same biomass, as they successively renewed the ferric iron oxyhydroxides rich oxidation layer through their deposition.