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

9814835萨拉自20世纪初以来，防火隔离和牲畜放牧在西北部内陆已导致开放黄松和西部落叶松林与内部道格拉斯冷杉密集的林分的演替取代。防火措施可能会严重损害我们保护北方落基山脉古老森林的能力。演替森林替代的生态影响，包括竞争压力的老树木在旧的增长残留的立场，穷人的物种更新比道格拉斯冷杉，改变水，碳和氮循环。管理的后果包括火灾危险增加、对病原体的敏感性增加和森林健康状况下降。美国林务局的山间火灾科学实验室正在计划一个项目，以恢复古老的火灾依赖黄松和落叶松。将对100年左右没有燃烧过的古老残林（约450年）进行几种处理：1）对照; 2）林下燃烧; 3）林下清除但不燃烧; 4）林上和林下燃烧间伐; 5）林上和林下清除间伐。这些治疗方法提供了一个非凡的机会，实验评估生态系统属性的变化，由于灭火。研究人员将在处理应用之前和之后测量五种处理的林分水平用水量、木材产量、树叶产量、树叶氮含量、水分利用效率和土壤水分可用性。结果将确定是否增加林分密度和林冠覆盖与灭火导致整个站水平用水量增加，但减少了用水量的老黄松和落叶松。

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.