Wildfire-produced charcoal directly influences nitrogen cycling in ponderosa pine forests
Wildfire-produced charcoal directly influences nitrogen cycling in ponderosa pine forests
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DOI：
10.2136/sssaj2005.0096
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发表时间：
2006-03-01
影响因子：
2.9
通讯作者：
Holben, WE
中科院分区：
文献类型：
--
作者：
DeLuca, TH;MacKenzie, MD;Holben, WE
火是温带和北方森林生态系统的主要干扰形式。然而，我们的知识的生化机制，火刺激森林氮循环是不完整的。木炭是森林火灾的主要副产品，在大多数森林生态系统的土壤中普遍存在，但木炭在森林生态系统土壤中的生物学功能却被极大地忽视了。我们进行了一套实验室实验，从黄松（美国黄松法律）森林土壤，以确定木炭对土壤氮动态，特别是硝化作用的影响。此外，NH 4+对森林土壤的硝化作用完全没有影响，表明这一过程是不受底物限制的。这些土壤与NH 4+和现场收集的木炭（1%w/w）的修正案显着增加硝化潜力，净硝化，总硝化，并降低植物次生化合物（酚类化合物）的溶液浓度。木炭没有影响硝化作用的土壤（从草原网站），具有自然高速率的硝化活性。森林土壤中总硝化作用的增加和缺乏对草原土壤的影响表明，木炭可能会减轻因素，否则会抑制森林土壤中硝化微生物群落的活性。这些结果揭示了木炭的生物学重要性，并推进了我们对火如何驱动温带和北方生态系统中营养循环的机械理解。
Fire is the primary form of disturbance in temperate and boreal forest ecosystems. However, our knowledge of the biochemical mechanisms by which fire stimulates forest N cycling is incomplete. Charcoal is a major byproduct of forest fires and is ubiquitous in soils of most forest ecosystems, yet the biological function of charcoal in soils of forest ecosystems has been greatly overlooked. We conducted a suite of laboratory experiments on soils from ponderosa pine (Pinus ponderosa Laws) forests to determine the influence of charcoal on soil N dynamics and in particular, nitrification. The addition of NH4+ to forest soils had absolutely no effect on nitrification demonstrating that this process is not substrate limited. The amendment of these soils with NH4+ and field collected charcoal (1% w/w) significantly increased the nitrification potential, net nitrification, gross nitrification, and decreased the solution concentrations of plant secondary compounds (phenolics). Charcoal had no effect on nitrification in soils (from a grassland site) that had naturally high rates of nitrifier activity. The increase in gross nitrification in forest soils and lack of effect on grassland soils suggests that charcoal may alleviate factors that otherwise inhibit the activity of the nitrifying microbial community in forest soils. These results reveal the biological importance of charcoal and advance our mechanistic understanding of how fire drives nutrient cycling in temperate and boreal ecosystems.