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About the Authors:
Scott L. Powell
* E-mail: [email protected]
Affiliation: Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, United States of America
Andrew J. Hansen
Affiliation: Department of Ecology, Montana State University, Bozeman, Montana, United States of America
Thomas J. Rodhouse
Affiliation: National Park Service, Upper Columbia Basin Network, Bend, Oregon, United States of America
Lisa K. Garrett
Affiliation: National Park Service, Southeast Region, Atlanta, Georgia, United States of America
Julio L. Betancourt
Affiliation: U.S. Geological Survey, National Research Program, Reston, Virginia, United States of America
Gordon H. Dicus
Affiliation: National Park Service, Upper Columbia Basin Network, Moscow, Idaho, United States of America
Meghan K. Lonneker
Affiliation: National Park Service, Upper Columbia Basin Network, Moscow, Idaho, United States of America
Introduction
Accelerated climate change presents daunting challenges to managers of protected natural areas at poleward and leading edges of species distributions [1], [2]. These areas are inherently dynamic and are likely to experience some of the most pronounced changes in community composition during an era of global change [3], [4], [5]. Where dominant native species expand into new terrain, such “natural invasions” could reduce and even eliminate other species and communities, a perceived negative outcome. Presumably, these changes could be reversed by appropriate management actions. However, invading native species may also provide beneficial habitat value and may be vulnerable to contraction and decline in other parts of their ranges. Native invaders, as peripheral populations, may harbor important genetic diversity and increased capacity for resilience to climate change and thereby increase the conservation value of protected areas at the range periphery [4], [6], [7]. Furthermore, efforts to slow or remove invaders may themselves be counterproductive. For example, controlled fires used to remove or thin native trees and shrubs can inadvertently facilitate invasions by non-native weeds [8], [9], [10]. This issue is further complicated in protected areas where other values and goals, such as the preservation of iconic landscapes, also influence the decision-making process.
Historically, the management of protected areas has been founded upon the assumption that ecosystem development is inherently linear and that ecosystems develop predictably along a single successional pathway [10], [11], [12]. But the accelerating rates of biological invasions and climate change, and a greater appreciation for the long-lasting legacies...