Invasive Species and Disturbances: Current and Future Roles of Forest Service Research and Development Mary Ellen Dix1, Marilyn Buford2, Jim Slavicek3, Forest Service Research and Development (R&D) priorities Allen M. Solomon4, and Susan G. Conard5 should focus on developing strategies, guidelines, and tools for mitigating invasive species and managing affected systems, as follows: Abstract • Modeling the introduction and spread of invasive species to help proactively predict and prevent the introduction and The success of an invasive species is in large part due to favor- establishment of an invasive species (also see prevention able conditions resulting from the complex interactions among paper). natural and anthropogenic factors such as native and nonnative • Decision support, detection and monitoring tools and pests, fires, droughts, hurricanes, wind storms, ice storms, strategies for predicting, preventing, detecting, and climate warming, management practices, human travel, and responding to newly arrived invasive threats (also see trade. Reducing the negative effects of invasive species and prevention paper). other disturbances on our natural resources is a major priority. Risk-cost-benefit analysis methodology to help determine Meeting this goal will require an understanding of the complex • the most effective management options. interactions among disturbances, development of tools to minimize new invasions, and effective management of systems • Strategies, systems, and practices for managing changed that have already been changed by invasive species. ecosystems to continue to deliver needed goods, services, and values. In this paper, we suggest desired resource outcomes; we offer • Tools that enable functional restoration of economically and/ considerations for developing management strategies, policies, or ecologically critical systems. and practices needed to achieve these outcomes; and we note Strategies and guidelines to prevent, detect, monitor, and potential interactions of invasive species with other distur- • manage invasive species after major disturbances. bances. We then identify invasive species-related research and development actions needed to achieve the desired outcomes. • Guidelines for economic, environmental, and social analysis. Interacting factors that influence desired outcomes include Resources needed to accomplish the foregoing outcomes weather conditions, fire, pests, land use decisions, transporta- include the following: tion, human health, human travel, and potential deployment of genetically engineered plants and animals. Disturbance and its 1. Modelers skilled in multiobjective stand dynamics and forest interactions with invasive species can have ecological, social, management modeling. and/or economic effects. 2. Integrative specialists whose expertise incorporates ecological, social, and economic effects. 1 National Program Leader for Forest Entomology Research, Forest Service, Research and Development, Washington Office, RPC-4, 1601 N. Kent St., Arlington, VA 22209. 2 National Program Leader for Silviculture Research, Forest Service, Research and Development, Washington Office, RPC-4, 1601 N. Kent St., Arlington, VA 22209. 3 Project Leader/Research Biologist, Forest Service, Northern Research Station, 359 Main Rd., Delaware, OH 43015. 4 Retired; formerly National Program Leader for Global Change Research, Forest Service, Research and Development, Washington Office, RPC-4, 1601 N. Kent St., Arlington, VA 22209. 5 Retired; formerly National Program Leader for Fire Ecology Research, Forest Service, Research and Development, Washington Office, 1601 N. Kent St., Arlington, VA 22209. A Dynamic Invasive Species Research Vision: Opportunities and Priorities 2009–29 91 3. Functional specialists who provide data relating to basic quality of life for present and future generations. processes and responses for use by integrative specialists and modelers. To meet this goal, we must consider the range and quantity of goods, services, and values that we will require our forests and 4. Communication specialists skilled in print, Web, and rangelands to produce in the coming decades. Figures 1 and 2 novel technology transfer processes to provide support to show estimates of world and U.S. populations from 1950 functional and integrative specialists. through 2050. As populations and world economies continue to increase, so will the societal demands on our natural resources. We will rely on these lands to produce water, wood and non- Introduction wood products, recreational opportunities, biological diversity, and energy, all while playing a crucial role in climate change The Forest Service and numerous other Federal, State, local, mitigation. and private organizations recognize invasive species as a significant environmental and economic threat to the Nation’s Although invasive species can have direct effects on many forests and rangelands. Interactions among invasive species and of these goods and services, it is important to recognize that other environmental and anthropogenic disturbance regimes these effects can also be greatly influenced by interactions can exacerbate this threat (USDA Forest Service 2003). Actions with fire, weather and climate patterns, land use changes, and taken to prevent, manage, and mitigate the adverse effects of other disturbances. The influence of invasive species on critical invasive species and other threats depend on understanding the natural resources may be increased or decreased in the context synergism among these disturbances and the potential effects of of other disturbances. both disturbances and proposed mitigations on resources and on people’s lives. Future management, policy, and societal needs for research related to managing forests and rangelands under the influence In this paper we suggest desired resource outcomes; consider- of invasive species can largely be met through quantifying ations in developing management strategies, systems, policies, and projecting system behavior and value under different and practices needed to achieve these outcomes; and potential scenarios. At varying time and space scales, these needs interactions of invasive species with other disturbances. We include probabilistic projections of the magnitude and direction then identify invasive species-related research and development of change; likely outcomes without intervention; options for actions needed to achieve these outcomes. In the broad sense, management actions, including their costs; and systems and our desired resource outcome is that forest and range ecosys- practices for accomplishing these actions. Critical research tems are healthy and productive and provide a sustainable deliverables include methods and tools for cost-benefit-risk supply of services, products, and experiences that enhance the Figure 1.—World population and estimates, 1950–2050 Figure 2.—U.S. population and estimates, 1950–2050 (U.S. (United Nations 2007). Census Bureau 2004). 92 A Dynamic Invasive Species Research Vision: Opportunities and Priorities 2009–29 analysis for invasive species management options; collection ecosystems and with other disturbances. Such understanding of the basic data needed to populate, parameterize, and develop is critical to sustainable management of the Nation’s natural these models; strategies, systems, and practices for managing resources. Our challenge over the next 50 years is to enhance changed systems to continue to deliver needed goods, services, our ability to predict and monitor these phenomena sufficiently and values; and the ability to articulate what changed systems to develop effective strategies to productively manage systems can and cannot deliver in probabilistic terms. increasingly affected by invasive species and to recognize and capitalize on any benefits. The situation is urgent because population increases, human movement, global trade, and Forest and Rangeland Disturbances climate change will continue to drive changes in the world’s biota—increasing the number and complexity of invasive spe- A diverse group of natural environmental disturbances has the cies and disturbance interactions. potential to alter our Nation’s forests and rangelands, including native pests, drought, fire, hurricanes, tornadoes, and ice storms. Key Disturbances Also a number of anthropogenic disturbances can potentially Our future success in both preventing introduction and estab- affect natural resources; these disturbances include nonnative lishment and managing spread of invasive species depends on invasive species, international and regional trade, transporta- our understanding of the interactions of diverse environments tion, development, and fragmentation. These disturbances can and disturbances as they impact invasive species ecology, occur individually but often come in combination, and interac- and on our ability to manage ecosystems to minimize adverse tions among these inherent and anthropogenic disturbances outcomes. Key disturbances that can impact invasive species are not well understood. Despite our lack of understanding, we success include: severe or changing weather and climate know these disturbances (and their interactions) can disrupt conditions; fire regimes and their management; insect pests ecosystem functions, social benefits, and economies. The and diseases; land use and land cover changes; trade and trans- resulting effects can be severe and may cause significant lasting portation within and across regions; human health and travel; ecological