Countryside Survey: National "Soil Change" 1978-2007 for Topsoils in Great Britain-Acidity, Carbon, and Total Nitrogen Status
Countryside Survey: National "Soil Change" 1978-2007 for Topsoils in Great Britain-Acidity, Carbon, and Total Nitrogen Status
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DOI：
10.2136/vzj2012.0114
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发表时间：
2013-05-01
影响因子：
2.8
通讯作者：
Emmett, B. A.
中科院分区：
文献类型：
--
作者：
Reynolds, B.;Chamberlain, P. M.;Emmett, B. A.
了解“土壤变化”在全国范围内，除了土壤状况，是一个关键的挑战，国家规模的土壤监测方案，是必不可少的，如果要实现更可持续地利用这一有限的资源。我们目前的结果，从第一次全国范围内的土壤变化调查报告三次在欧洲，也许是全球范围内，涵盖了30年的时间跨度。农村调查是一项综合性的国家监测计划，测量植被;表土物理，化学和生物特性（0-15厘米）;水质;以及英国各地的土地利用，从而认识到它们的相互依赖性。在这里，我们报告的基本土壤化学特性的变化。1978年、1998年和2007年测定了土壤pH值和烧失量（LOI），1998年和2007年测定了土壤全氮（总N）浓度和C/N比。2007年测量了堆积密度。从1978年到1998年到2007年，平均土壤pH值在酸性较低的土壤中显着增加。1978年至1998年，但不是1998年和2007年之间，平均pH值显着增加，在更酸性，有机质丰富的土壤，表明空间趋势的硫沉降减少和土壤的敏感性。1978年至1998年，GB表层土壤C浓度（根据LOI计算）略有增加（8%），1998年至2007年略有下降（6.5%），1978年至2007年总体变化不大。这些结果之间的未解决的差异，从英格兰和威尔士的国家土壤清单，报告大规模的大幅度减少土壤中的C浓度在2005年进行了讨论。有意想不到的小，但显着减少，总氮浓度在许多广泛的栖息地，尽管持续大气氮沉降。在人工自然和林地栖息地，这是伴随着C/N比的增加，表明一个可能的解释是氮信号的稀释，由于高C/N凋落物输入导致初级生产力增加，如其他地方报道的，由于一系列全球驱动因素，如增加CO2，N和温度。在可耕地系统中，碳和氮的可比损失率表明侵蚀损失或深耕正在降低土壤状况。讨论了环境变化的主要驱动因素对土壤过程的影响以及考虑特定生境趋势的重要性。
Understanding "soil change" at the national scale, in addition to soil status, is a key challenge for national scale soil monitoring programs and is essential if more sustainable use of this finite resource is to be achieved. We present results from the first national scale survey of soil change to be reported three times within Europe and perhaps globally, covering a 30-yr time span. Countryside Survey is an integrated national monitoring program that makes measurements of vegetation; topsoil physical, chemical, and biological characteristics (0-15 cm); water quality; and land use across Great Britain (GB), thus recognizing their interdependence. Here we report on change in fundamental soil chemical characteristics. Soil pH and loss on ignition (LOI) were measured in 1978, 1998, and 2007 and soil total nitrogen (total N) concentration and C/N ratio in 1998 and 2007. Bulk density was measured in 2007. Mean soil pH increased significantly in less acidic soils from 1978 through 1998 to 2007. Mean pH increased significantly in more acidic, organic-rich soils from 1978 to 1998 but not between 1998 and 2007, indicating spatial trends in both sulfur deposition reductions and soil sensitivity. There was a small increase (8%) in GB topsoil C concentration (calculated from LOI) between 1978 and 1998, a small decrease (6.5%) between 1998 and 2007, and no significant overall change between 1978 and 2007. The unresolved difference between these results and those from the National Soil Inventory of England and Wales that reported wide-scale large decreases in soil C concentrations in 2005 are discussed. There were unexpected small but significant decreases in total N concentration in many broad habitats despite continuing atmospheric nitrogen deposition. In seminatural and woodland habitats, this was accompanied by an increase in the C to N ratio, indicating one possible explanation is dilution of the nitrogen signal due to high C/N litter inputs resulting from increased primary productivity as reported elsewhere due to a range of global drivers such as increased CO2, N, and temperature. In arable systems, comparable rates of loss of C and N suggest erosion losses or deep plowing are reducing soil condition. The results are discussed in relation to the influences on soil processes of key drivers of environmental change and the importance of considering habitat-specific trends.