The Control of Long-term Carbon and Nitrogen Dynamics in Conifer Logs by the Microelement Manganese

微量元素锰对针叶树原木长期碳氮动态的控制

• 批准号: 8918643
• 负责人: Mark Harmon
• 金额: $ 45万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8918643&HistoricalAwards=false
• 关键词: Control; Long; term; Carbon; Nitrogen

THE CONTROL OF LONG-TERM CARBON AND NITROGEN DYNAMICS IN CONIFER LOGS BY THE MICROELEMENT MANGANESE This research will test the hypothesis that the long-term carbon and nitrogen dynamics of conifer logs is controlled by the availability of the microelement manganese. Recent research has revealed that a major lignin degradative pathway is controlled by oxidative reactions involving Mn. Prior research has revealed marked differences in the initial Mn concentrations in conifer wood, and these differences correspond to species susceptible to brown-rot (little lignin degraded) versus those susceptible to white-rot (lignin and cellulose breakdown). Since lignin comprises approximately one-third of the original conifer wood, the type of decomposition pathway followed controls the amount of long-term carbon storage. Therefore, this research will have direct implications for understanding the role of coarse woody debris (CWD) in global carbon storage. Harmon, Jarrell and Caldwell hypothesize that: 1) early changes in carbon and nitrogen dynamics are controlled by decomposer colonization patterns, 2) long-term carbon dynamics are controlled by the availability of the microelement Mn which determines, in part, whether lignin is decomposed, and 3) nitrogen dynamics are controlled by the abundance of available carbon and not total carbon. To test these hypotheses the investigators will conduct a three year study of carbon and nitrogen dynamics that examines changes in wood cell wall chemistry, manganese availability, microbial physiology and biochemistry, nitrogen dynamics and mass losses in decomposing logs from different coniferous ecosystems. They will also continue development of a decomposition model that predicts long- term carbon and nitrogen dynamics for many species and sizes of logs. Harmon, Jarrell and Caldwell are innovative and productive investigators of the role of woody debris in forested ecosystems. The are part of the outstanding team of forestry researchers at Oregon State University.

针叶树长期碳氮代谢的控制 微量元素锰测井 这项研究将检验这样一个假设：从长远来看， 针叶树原木的碳氮动态受 微量元素锰的有效性。 最近的研究 揭示了一个主要的木质素降解途径是由 涉及Mn的氧化反应。 先前的研究显示， 针叶树中锰的初始浓度存在显著差异 木材，这些差异对应于易受 褐腐（木质素降解很少）与易受 白腐病（木质素和纤维素分解）。 由于木质素 包括大约三分之一的原始针叶树木材， 分解途径的类型控制着 长期储存碳。 因此，这项研究将有 对理解粗木质的作用的直接影响 CWD（CWD）在全球碳储量中的作用。 哈蒙、贾德尔和考德威尔假设：1）早期 碳和氮的动态变化由以下因素控制： 分解者定殖模式，2）长期碳动态 由微量元素Mn的可用性控制， 部分地决定木质素是否被分解，以及3） 氮的动态是由丰富的可用 碳，而不是总碳。 为了验证这些假设， 研究人员将对碳进行为期三年的研究， 氮动力学，检查木材细胞壁的变化 化学，锰的有效性，微生物生理学和 生物化学、氮动态和分解过程中的质量损失 来自不同针叶林生态系统的原木。 他们还将 继续开发分解模型，预测长期 长期碳和氮动态的许多物种和大小的 日志. 哈蒙、贾格尔和考德威尔富有创新精神，而且富有成效 研究木质残体在森林生态系统中的作用。 他们都是杰出的林业研究人员团队的一员， 俄勒冈州州立大学。