Dissertation Research: Forest Fire Mitigation and Understory Invasion

摘要本论文项目的目的是测试与森林间伐作业相关的活动是否能有效抑制科罗拉多州森林中杂草的建立。如果有效，这种管理工具将比广泛使用除草剂更具成本效益和生态效益。一种常见的防火方法是在现场削碎并铺开变薄的木材。其他研究发现，木屑改进剂可以降低土壤氮的有效性，从而改变植物群落的物种组成。由于科罗拉多州的原生植物很好地适应了土壤氮的低有效性，木屑改良剂可以选择性地抑制非本地杂草。因此，本项目检验了木屑改良剂影响土壤化学和物理性质以抑制杂草形成的假设。这项工作涉及两个关键问题的科学/管理界面：森林火灾缓解和外来物种控制。研究结果将确定在物理和化学干扰共同发生的情况下，防火程序如何影响生态系统抵御杂草入侵的能力。除了直接适用于当地管理问题（美国林业局、博尔德县开放空间和落基山国家公园）之外，该项目还包含了城市学童和当地公民的教育推广部分。

Dissertation Research: Forest Fire Mitigation and Understory InvasionTimothy Seastedt and Elisa MillerProposal #: 0508871 ABSTRACT The purpose of this dissertation project is to test if activities associated with forest thinning operations can effectively inhibit weed establishment in thinned Colorado forests. If effective, such a management tool would be significantly more cost-effective and ecologically sound than widespread application of herbicides. A common fire mitigation practice is to chip and spread the thinned wood on-site. Other studies have found that sawdust amendments can reduce soil nitrogen availability and thereby alter the species composition of the plant community. As native Colorado plants are well adapted to low availability of soil nitrogen, wood chip amendments may selectively inhibit non-native weeds. Thus, this project tests the hypothesis that wood chip amendments affect the chemical and physical properties of soil to inhibit the establishment of weeds. This work addresses a concern at the science/management interface of two critical issues: forest fire mitigation and exotic species control. The results will identify how fire mitigation procedures affect the ability of an ecosystem to resist weed invasions in the context of co-occurring physical and chemical disturbances. In addition to its direct applicability to local management concerns (US Forest Service, Boulder County Open Space, and Rocky Mountain National Park), this project also incorporates an educational outreach component for urban schoolchildren and local citizens.