Landscape Configurations in Yellowstone National Park: An Alternative State Stabilized by Herbivory?

人类的行为可能会对自然造成意想不到的影响。 通常，这些行为会导致自然系统从其历史条件突然改变为可能不受欢迎的新条件。 从黄石国家公园中清除狼群似乎是一种对公园生态系统造成意想不到的损害的行动，特别是从溪流走廊中损失树木和灌木。 这些植物提高水质，稳定河岸，并为许多野生动物提供栖息地。 看来，消除狼允许麋鹿种群达到的水平，他们的浏览阻止杨柳繁殖和增加杨柳死亡率。海狸的消失和大部分杨柳栖息地的消失导致了溪流的根本变化，使它们不太适合作为柳树的栖息地。 这项研究将确定狼重新引入黄石国家公园是否使北方范围恢复到其历史条件与丰富的杨柳社区和蓬勃发展的海狸种群。 将使用多种方法，包括评估航空照片和系统的定量建模。美国国家科学院的一份报告指出，了解水的可用性和麋鹿对柳树群落的浏览影响是黄石国家公园政策和管理的一个紧迫问题。国家公园。 拟议的工作将在一个可以立即应用科学的地方解决一个具有基本科学价值的问题。 这项工作为向公民、管理人员和决策者传播科学提供了一个宝贵的机会。

Human actions can cause unintended effects on nature. Often, these actions can cause natural systems to change abruptly from their historic condition to new conditions that may be undesirable. The removal of wolves from Yellowstone National Park appears to be an action that has caused unanticipated harm to the ecosystems of the park, in particular, the loss of trees and shrubs from stream corridors. These plants enhance water quality, stabilize stream banks, and provide habitat for many species of wildlife. It appears that elimination of wolves allowed elk populations to reach levels where their browsing prevented willow reproduction and increased willow mortality. The absence of beaver with the demise of much of the willow habitat, resulted in fundamental changes in streams, rendering them less suitable as habitat for willows. This study will determine whether the re-introduction of wolves to Yellowstone National Park has allowed the northern range to recover to its historic condition with abundant willow communities and vigorous populations of beaver. Several approaches will be used including assessments of aerial photographs and quantitative modeling of the system.A National Academy of Sciences report identified understanding the effects of availability of water and browsing by elk on communities of willows as a problem of urgent importance for policy and management in Yellowstone National Park. The proposed work will address a problem of fundamental scientific value in a location where science can be immediately applied. The work provides a valuable opportunity to communicate science to citizens, managers and policy makers.