SGER: Restoring Old-Growth Ponderosa Pine and Western Larch Stands in Western Montana

SGER：恢复蒙大拿州西部的老黄松和西部落叶松林

• 批准号: 9814835
• 负责人: Anna Sala
• 金额: $ 1.5万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-15 至 1999-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814835&HistoricalAwards=false
• 关键词: SGER; Restoring; Old; Growth; Ponderosa

9814835 Sala Since the early 1900's, fire exclusion and livestock grazing in the interior northwest have resulted in a successional replacement of open ponderosa pine and western larch stands with dense stands of interior Douglas-fir. Fire exclusion may seriously compromise our ability to preserve old-growth forests in the northern Rocky Mountains. The ecological implications of successional forest replacement include competitive stress on the older trees in old-growth remnant stands, poor regeneration of species other than Douglas-fir, and alteration of water, carbon and nitrogen cycles. Management consequences include increased fire hazard, increased susceptibility to pathogens and decreased forest health. The Intermountain Fire Sciences Laboratory of the US Forest Service is planning a project to restore old-growth fire-dependent ponderosa pine and larch. Several treatments will be applied to an old-growth remnant stand (ca 450 years) which has not burned in about 100 years: 1) control; 2) understory burn; 3) understory removal but no burn; 4) thinning of overstory and understory burn; and 5) thinning of overstory and understory removal. These treatments provide an extraordinary opportunity to experimentally assess changes in ecosystem properties due to fire suppression. The investigators will measure stand-level water use, wood production, foliage production, foliage nitrogen context, water use efficiency, and soil water availability in the five treatments before and after treatment application. Results will determine whether increases in stand density and canopy cover associated with fire suppression has resulted in an increased whole stand-level water use, but has decreased water used by old ponderosa pines and larches.

9814835 Sala 自 1900 年代初以来，西北内陆地区的火灾排除和牲畜放牧导致开阔的黄松和西部落叶松林地相继被茂密的内陆花旗松林所取代。防火可能会严重损害我们保护落基山脉北部原始森林的能力。连续森林更替的生态影响包括对古老残存林中老树的竞争压力、花旗松以外的物种再生不良以及水、碳和氮循环的改变。管理后果包括火灾危险增加、对病原体的易感性增加以及森林健康状况下降。美国林务局山间火灾科学实验室正在规划一个项目，以恢复依赖火的古老黄松和落叶松。对约 100 年未燃烧的老树残林（约 450 年）进行几种处理： 1）控制； 2）林下燃烧； 3) 清除林下植物但不焚烧； 4）林下烧毁林间疏伐； 5) 疏伐上层植被并清除下层植被。这些处理方法为通过实验评估灭火引起的生态系统特性变化提供了绝佳的机会。研究人员将测量处理前后五种处理中的林分用水量、木材产量、叶子产量、叶子氮含量、水分利用效率和土壤水可用性。结果将确定与灭火相关的林分密度和树冠覆盖率的增加是否导致整个林分水平用水量增加，但减少了老黄松和落叶松的用水量。