Water and mass exchanges in mosses: Towards an understanding of the movement of solutes and hydrocarbons

泥炭地约占加拿大陆地面积的14%，那里的气候和地形导致土壤持续潮湿。由于氧气在湿润土壤中的扩散很差，在那里生长的植被在死亡时会缓慢腐烂，导致有机碳的积累，或称泥炭。泥炭是陆地上最大的碳汇，因此具有全球意义。泥炭主要是由苔藓形成的，因为它们耐腐烂。加拿大的许多泥炭地受到园艺泥炭收获和造成污染的工业活动的破坏。了解苔藓的水分动态及其如何影响碳吸收是这项研究的目标之一。如果我们认识到苔藓的水分需求，就可以管理收获的泥炭地，为苔藓提供最佳条件。被工业活动、管道破裂或火车脱轨污染的泥炭地需要采取补救或保护邻近地区的战略。然而，关于泥炭地中溶解于水的化学物质或石油基流体(碳氢化合物)的运输的知识非常贫乏。随着对水在苔藓中如何运动的了解的加深，我们可以专注于溶解物质是如何运输的，以及它们是否会沿着不饱和的苔藓剖面向上迁移，从而威胁到苔藓的死亡。这项研究考察了这些运输过程。最后，凭借对溶解化学物质运输的了解，这项研究将研究碳氢化合物(不容易溶解的)如何在苔藓层中移动，哪些过程会抑制移动或鼓励其分解。这项研究建议将重点放在昆士兰L附近的一个地点，2004年，一列货运列车脱轨，将约200,000升汽油和取暖油泄漏到一片沼泽泥炭地上。该地点仍然受到污染，但如果没有这项研究，任何关于如何(或是否)补救它的决定都不会在对过程有很好的了解的情况下做出。

Peatlands comprises ~14% of Canada's land area where climate and landscape result in persistently wet soil conditions. Because of poor oxygen diffusion into wet soil, the vegetation growing there decays slowly when it dies, resulting in the accumulation of organic carbon, or "peat". Peat formation is the largest terrestrial carbon sink, so is of global significance. Peat is dominantly formed by mosses because they are resistant to decay. Many peatlands in Canada are damaged by horticultural peat harvesting and by industrial activities that cause contamination. Understanding the moisture dynamics of mosses and how it affects carbon uptake is one goal of this study. Harvested peatlands can be managed to provide optimal conditions for mosses if we recognize their water needs. Peatlands that have been contaminated by industrial activities, burst pipelines or train derailments require strategies for remediation or protection of adjacent areas. However, knowledge of the transport of chemicals dissolved in water, or of petroleum-based fluids (hydrocarbons) in peatlands, is very poor. With the improved understanding of how water movement occurs in mosses, we can focus on how dissolved substances are transported, and whether they can migrate up the unsaturated moss profile and threaten to kill the mosses. This study examines these transport processes. Finally, with knowledge of transport of dissolved chemicals, this study will examine how hydrocarbons (which do not readily dissolve) move in the moss layer, what processes inhibit movement or encourage its breakdown. The research proposes to focus on a site near Lévis, QC, where in 2004 a freight train derailment spilled ~200,000 litres of gasoline and heating oil onto a bog peatland. The site is still contaminated, but without this study any decisions on how (or if) to remediate it will not be made with a good understanding of the processes.