Deep Root Distribution and Function in Amazonian Ecosystems

亚马逊生态系统的深根分布和功能

• 批准号: 8911403
• 负责人: Christopher Uhl
• 金额: $ 25万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8911403&HistoricalAwards=false
• 关键词: Deep; Root; Distribution; Function; Amazonian

Large-scale ranching and logging operations are converting mature, forested ecosystems of Amazona to frequently-burned, regrowth forest. In a mature forest relict at the heart of an Amazonian ranching and lumbering center, root systems extend to at least 12 m depth and apparently enable this ecosystem to maintain carbon assimilation and transpiration through the 5 month dry season. The project will evaluate the hypothesis that frequently- burned, regrowth forests (1) are shallow-rooted, (2) extract less water from the soil during the dry season and (3) store less rainfall in the soil during the wet season in comparison to the mature forests that they are replacing. These prediction are tested by a comparative study of root distribution, fine root growth, soil water availability, soil water uptake and rainfall storage in mature forest, intact regrowth forest, and recently- burned regrowth forest. This will be accomplished using a network of soil shafts, 7 m deep, in which measurements of root distribution and monitoring spatial and temporal patterns of root growth, soil water potential and soil water content will be observed. The studies proposed here will ask basic questions about an important, but previously neglected aspect of ecosystem structure and function within the context of a rapidly changing tropical landscape. The investigator are well qualified for this type of research and have more than adequate institutional support.

大规模的牧场和伐木作业正在将亚马逊的成熟的森林生态系统转变为频繁燃烧的再生森林。在亚马逊牧场和伐木中心中心的一片成熟的森林残留物中，根系延伸到至少12米深，显然使这个生态系统在5个月的旱季中保持碳的同化和蒸腾。该项目将评估以下假设：频繁燃烧的再生森林(1)是浅根森林，(2)旱季从土壤中提取的水分较少，(3)与它们正在取代的成熟森林相比，在雨季土壤中储存的降雨较少。通过对成熟林、完整再生林和新近砍伐的再生林的根系分布、细根生长、土壤水分有效性、土壤吸水量和降雨蓄积的比较研究，对这些预测进行了验证。这将使用7米深的土壤竖井网络来完成，在该网络中将观测根系分布并监测根系生长、土壤水势和土壤水分的空间和时间模式。这里提出的研究将提出关于在快速变化的热带景观背景下生态系统结构和功能的一个重要但以前被忽视的方面的基本问题。研究人员完全有资格从事这类研究，并有足够的机构支持。