Browsing by red deer negatively impacts on soil nitrogen availability in regenerating native forest
Browsing by red deer negatively impacts on soil nitrogen availability in regenerating native forest
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DOI：
10.1016/j.soilbio.2003.08.022
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发表时间：
2004
影响因子：
9.7
通讯作者：
K. A. Harrison;R. Bardgett
中科院分区：
文献类型：
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作者：
K. A. Harrison;R. Bardgett
食草动物可以对控制生态系统形态和生产力的地下特性和过程产生重要的间接影响。食草动物影响生态系统生产力的一个主要方式是通过改变优势植物和地下属性之间的反馈，特别是通过改变营养物质矿化的速率。在这项研究中，我们研究了马鹿在苏格兰高地高地高地更新森林中对土壤生物学特性和N循环的影响，相对于景观因素，如小气候和地形的变化。在2001年的生长季节，苏格兰高地的Creag Meagaidh地点进行了三次采样，并从四个封闭点取了土芯。对土壤生物特性和氮素有效性进行了测定。结果表明，时空变化是影响该生态系统土壤生物学特性和氮动态的主要因素，但草食对这些指标也有一致且显著的影响。浏览显著降低了DOC（27%）、NO3−(48%)、NH4+(49%)和n矿化（53%）的测量值。放牧区微生物碳氮比（C:N）显著高于放牧区（89%），表明鹿的去除降低了微生物群落氮限制的程度。这些对土壤氮循环的显著负面影响有可能降低生态系统的生产力。我们的结论是，在14年的时间里，砍伐树木加速了原生林地的更新，导致土壤C和N矿化的增加，进一步增加了该生态系统中植物N的供应和树木的生长。
Herbivores can have important indirect effects on belowground properties and processes that govern ecosystem form and productivity. A major way that herbivores affect ecosystem productivity is by modifying feedbacks that occur between dominant plants and belowground properties, and especially by changing the rates of nutrient mineralisation. In this study, we examine the effects of browsing by red deer, relative to landscape factors such as variations in microclimate and topography, on soil biological properties and N cycling in regenerating forest in an upland region of the Scottish Highlands. The site at Creag Meagaidh in the Scottish Highlands was sampled three times over the growing season of 2001 and soil cores were taken from four exclosures. Measures of soil biological properties and nitrogen availability were made. The results presented here suggest that although spatial and temporal variation were the dominant factors affecting soil biological properties and nitrogen dynamics in this ecosystem, herbivory also had consistent and significant effects on these measures. Browsing significantly reduced measures of DOC (27%), NO3−(48%), NH4+(49%) and N-mineralisation (53%). The microbial C:N ratio was also significantly greater (89%) in browsed than un-browsed areas, suggesting that the removal of deer reduced the extent that the microbial community was N-limited. These significant negative effects of browsing on soil nitrogen cycling have the potential to reduce ecosystem productivity. We conclude that removal of browsing over 14 years has accelerated native woodland regeneration, leading to subsequent increases in soil C- and N-mineralisation, further increasing plant N supply and tree growth in this ecosystem.