《Wetlands》杂志刊登“Brinson评论：关于营养物对滨海湿地可持续发展影响的观点”

作者：J. T. Morris, G. P. Shaffer, J. A. Nyman

刊物：《Wetlands》,2013年10月

关键词：氮；营养物；植物发育；密西西比河三角洲；沉积物有机质；分解；转移；沉积物；沼泽修复；初级生产；模型

摘要：关于改变密西西比河三角洲的湿地损失的现状，其中的一个解决方案是建立河道使河流悬浮泥沙重新改道。在诸如密西西比三角洲这种相对海平面快速上升的地区，有一种观点被普遍接受，即洪水中的沉积物和矿物沉积物对维持湿地是十分关键的。但是创建改道计划对密西西比河中的营养携带产生影响，作用可能会减弱泥沙效益。本文认为理论的和经验的证据都证实营养物对地上和地下的植被生长都有益，并且淡水和泥沙改道对三角洲地区的湿地修复是非常有效且有益的，特别是旨在泥沙输入最大化的三角洲地区。输入的泥沙、营养物以及淡水将会改变一些湿地的群落组成和它们的生物地球化学过程。大部分的氮输入应该被同化或反硝化。活性有机质可能迅速地降低，活性有机质不会增加新的土壤体积，衰减的速度产生的后果也很小。为了能完全理解沉积物中有机质保存营养的结果需要开展更多的研究，但是基于已知的木质素降解真菌和酶的活动，很可能是难降解的有机物增加并促进泥沙的淤积。新英格兰泥炭沉积物盐沼和以矿物为主的东南盐沼地带中进行的长期淤积泥沙研究也支持了这一观点，研究发现有机质丰富的沼泽其海拔与参考地区的相同或者更高。

Brinson Review: Perspectives on the Influence of Nutrients on the Sustainability of Coastal Wetlands

Authors: J. T. Morris, G. P. Shaffer, J. A. Nyman

Journal: Wetland, October 2013

Key words: Nitrogen; Nutrient; Plant development; Mississippi River Delta; Sediment organic matter; Decomposition; Diversion; Sedimentation; Marsh restoration; Primary production; Model

Abstract: Among the solutions being proposed for reversing wetland loss in the Mississippi River Delta are the creation of diversions to reintroduce suspended sediment carried in the river. In areas of rapid relative sea-level rise, as in the Mississippi Delta, it is generally accepted that a supply of sediment in flood water and mineral sedimentation are critical to sustaining wetlands. But plans to create diversions have raised questions about the collateral effects of nutrients carried in the Mississippi River, effects that may contravene the benefits of sediment. This review finds the balance of empirical and theoretical evidence supports that nutrients benefit above- and belowground plant production and that fresh water and sediment diversions can be effective and beneficial for restoring wetlands in the Delta, especially if designed to maximize sediment inputs. The input of sediment, nutrients, and fresh water will change the community composition of some wetlands and their biogeochemical processes. Most of the nitrogen input should be assimilated or denitrified. Labile organic matter is likely to degrade more quickly, but labile organic matter does not add ‘new’ soil volume and its speed of decay is of little consequence. Additional research is needed before we fully understand the consequences of nutrients on the preservation of organic matter in sediment, but building on what is known of the activities of lignin-degrading fungi and their enzymes, it is likely that refractory organic matter should increase and contribute positively to sediment accretion. This is supported by long-term studies of sediment accretion in a New England salt marsh with peat sediment, and in a mineral-dominated southeastern salt marsh, that show elevations in fertilized plots gained as much or more than in reference plots.

原文链接：http://link.springer.com/article/10.1007/s13157-013-0480-3