Effects of oil on internal gas transport, radial oxygen loss, gas films and bud growth in Phragmites australis
Effects of oil on internal gas transport, radial oxygen loss, gas films and bud growth in Phragmites australis
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DOI：
10.1093/aob/mcn213
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发表时间：
2009-01-01
期刊：
影响因子：
4.2
通讯作者：
Armstrong, William
中科院分区：
文献类型：
--
作者：
Armstrong, Jean;Keep, Rory;Armstrong, William
湿地的石油污染是一个世界性的问题，但迄今为止，研究集中在其对盐沼的影响，而不是淡水植物群落。水性轻质油的作用研究了不同浓度的液体石蜡和柴油对芦苇（Phragmites australis）的石油渗透、气体内部输送、径向氧损失、水下气膜和芽生长的影响，分析了不同浓度石油对芦苇节髓腔和叶鞘通气组织压力流阻力的影响，从施加压力下的流速记录。对流流动进行了测量，从生活切除秆油和非油节点和叶鞘。用极谱法测定了茎基节周围油对根状茎和根尖ROL的影响。实验记录了浸油处理和不浸油处理的潜生枝表面气体膜。芽的生长和出现，通过水与无油film.Internodes几乎是不可渗透的，但节点的衰老和活秆渗透油，可以阻止髓腔隔膜，防止在施加的压力为1千帕的流动，自然对流运输到根茎，并大大降低叶际和根际的ROL。油渗透或覆盖活叶鞘防止湿度引起的对流。石油取代了纹层和叶鞘表面的气膜。油通过节和叶鞘气孔渗入气体空间系统，减少O（2）扩散和对流进入根茎系统，降低叶圈和根圈的氧化;通过气膜进行的水下气体交换将受到阻碍。植物会因油诱导的发芽失败而衰弱。植物在生长季节面临的风险最大。
Oil pollution of wetlands is a world-wide problem but, to date, research has concentrated on its influences on salt marsh rather than freshwater plant communities. The effects of water-borne light oils (liquid paraffin and diesel) were investigated on the fresh/brackish wetland species Phragmites australis in terms of routes of oil infiltration, internal gas transport, radial O(2) loss (ROL), underwater gas films and bud growth.Pressure flow resistances of pith cavities of nodes and aerenchyma of leaf sheaths, with or without previous exposure to oil, were recorded from flow rates under applied pressure. Convective flows were measured from living excised culms with oiled and non-oiled nodes and leaf sheaths. The effect of oil around culm basal nodes on ROL from rhizome and root apices was measured polarographically. Surface gas films on submerged shoots with and without oil treatment were recorded photographically. Growth and emergence of buds through water with and without an oil film were measured.Internodes are virtually impermeable, but nodes of senesced and living culms are permeable to oils which can block pith cavity diaphragms, preventing flows at applied pressures of 1 kPa, natural convective transport to the rhizome, and greatly decreasing ROL to phyllospheres and rhizospheres. Oil infiltrating or covering living leaf sheaths prevents humidity-induced convection. Oil displaces surface gas films from laminae and leaf sheaths. Buds emerge only a few centimetres through oil and die.Oil infiltrates the gas space system via nodal and leaf sheath stomata, reducing O(2) diffusion and convective flows into the rhizome system and decreasing oxygenation of phyllospheres and rhizospheres; underwater gas exchange via gas films will be impeded. Plants can be weakened by oil-induced failure of emerging buds. Plants will be most at risk during the growing season.