Biogeochemical cycling of N in tropical coastal zones: molecular microbial ecology of trace gas production.

海岸带在控制地球元素自然循环的地球化学过程中极为重要。特别是，沿海地区对氮循环有很大的贡献，它清除了河流从陆地上冲刷进来的氮，从而减少了氮对沿海海洋的负面影响。然而，这些由微生物驱动的去除过程也有助于氮气的形成，其中一些（N2O，NO，NO2）在全球变暖中很重要。虽然已经做了大量的工作来测量这些过程在温带沿海地区，有很少知道它们是如何发生在热带沿海地区，也无论是微生物带来的过程是相同的或不同的那些在温带地区。最近的信息表明，这些区域之间可能存在重大差异，如果我们要了解它们在全球的重要性，就需要了解这些差异。我们打算用氮的稳定同位素示踪剂测量几种热带海岸沉积物中这些重要过程的速率，以及氮循环的不同终产物的相对重要性。此外，我们将适用于分子微生物学的N循环，在科尔恩河口开发的技术，热带沉积物，以确定微生物是否是不同的或相同的在温带河口，以及是否不同的微生物群体占主导地位的两个地区。

The coastal zone is extremely important in the biogeochemical processes which control the natural cycle of elements of the Earth. In particular, the coastal zone contributes significantly to the nitrogen cycle, removing nitrogen washed in from the land by rivers and so reducing its fertilizing impact on the coastal seas. However, these removal processes, driven by microorganisms, also contribute to the formation of nitrogen gases, some of which (N2O, NO, NO2) are important in global warming. While a lot of work has been done to measure these processes in temperate coastal regions, there is little known about how they occur in the tropical coastal zone nor whether the microorganisms bringing about the processes are the same or different to those in temperate regions. Recent information suggests that there may be significant differences between these regions which we need to know about if we are to be able to understand their importance globally. We intend to measure the rates of these important processes in several tropical coastal sediments, and the relative importance of the different endproducts of N cycling, using stable isotope tracers of N. In addition, we will apply the techniques of molecular microbiology of N cycling, developed in the Colne estuary, to tropical sediments to determine whether the microorganisms are different or the same as in temperate estuaries; and whether different groups of microorganisms predominate in the two regions.