New insights into soil formation, organic matter turnover and degradation of soils over long, decadal to millennial timescales

粮农组织最近指出，在60年内，我们地球的表土将因土壤退化而消失。在英国，土壤研究人员提出，“英国只剩下100年的收成了”。这些说法的科学依据尚不清楚。然而，它们确实指出了全球对世界土壤未来的关注，以及了解土壤可以继续提供关键土壤功能多久的重要性：土壤寿命。中等偏上（10年）至长期（100年）的时间尺度，我们假设土壤的寿命取决于土壤生产过程之间的平衡，例如矿物风化，以及去除土壤的那些，例如有机物分解。这些变化可能迅速发生，往往是由于人类的干预，例如土地利用变化后，表层土壤因侵蚀而流失，也可能发生得较慢，例如有机碳因气候变化而发生变化。也许令人惊讶的是，我们对土壤生产率的认识存在重大差距。如果我们要预测土壤的寿命，填充这些是至关重要的。迄今为止，土壤生产率调查仅限于美国西海岸和南澳的半自然植被，几乎没有在农业用地上进行测量。在英国，我们只有一个测量博德明摩尔。这个博士项目的目的是：1。确定土壤形成率在三个对比网站在英国;2。开发一个能够预测土壤寿命的模型;3.预测每个场地土壤链的土壤寿命。

The FAO has recently stated that within 60 years the topsoil of our planet will be lost via soil degradation . In the UK soil researchers have suggested that 'Britain has only 100 harvests left' . The scientific basis for these statements are unclear. However, they do point to the global concern over the future of the world's soils and the importance of understanding how long soils can continue to provide the critical soil functions: the soil lifespan.Over medium (10s of years) to long (100s of years) timescales we hypothesise that the soil's lifespan is dependent on the balance between the soil production processes e.g. mineral weathering, and those that remove soil e.g. organic matter decomposition. These changes may occur rapidly, often due to human interventions, for example the removal of the topsoil by erosion following land use change, or more slowly, such as changes in organic carbon in response to climate change. Perhaps surprisingly, there are major gaps in our knowledge of the rates of soil production. Filling these are critical if we are predict soil lifespan's . To date soil production rate investigations have been limited to semi natural vegetation on the West coast of the US and South Australia, with virtually no measurements in agricultural lands. In the UK we have only one measurement from Bodmin moor .The aims of this PhD project are to:1. Determine soil formation rates at three contrasting sites across the UK;2. Develop a model capable of predicting soil lifespans;3. Predict the soil lifespan for a soil catena at each of the sites.