Experimental Eradication of an Invasive Exotic Vine in the Trent University Nature Areas: Ecological Implications for the Management of Dog-Strangling Vine (Vincetoxicum Rossicum) Completed By: Kieran Pinder Course: Community-based Research Project (TCCBE) Supervisor: Dr. Tom Whillans Due: December 16, 2011 1 1. Abstract The Nature Areas Committee at Trent University oversees the natural heritage of the campus, and is committed to including students in community-based research projects which involve scientific experimental design projects. The experiment described here on out deals with restoration management of natural areas on the campus of Trent University and particularly focuses on introduced, non-native plants as a degrading force in these natural areas. Within the context of this report for the Trent Nature Areas Committee, an accredited course was established with the Trent Centre for Community-Based Education (TCCBE) that initiates the discussion on an emergent issue within many southern Ontario natural areas. This course focuses on the biology and ecological impacts of a plant which has escaped cultivation in North America, originally introduced from Eastern Europe and named the Dog- strangling vine (Vicetoxicum rossicum). This vine has found habitat in in areas of concern within the Trent NA. It is highly invasive as a perennial herbaceous plant, and has consequently infiltrated three particularly evident sites in the Trent NA, and therefore has potential to invade and dominate both the areas where it currently resides, as well as adjacent ecosystems of which are particularly vulnerable to widespread infestation in the future. Within these parameters of the V. rossicum species, this particular report will outline the implemented management techniques for controlling the spread of this plant. The program was initiated by the Trent Nature Areas Committee, and facilitated by the grounds-keeping crew of the Physical Resources department. It is aimed at discovering an effective chemical treatment method for managing V. rossicum. Outlined in this report will be the history of this particular plant invasion in eastern North America, detailed consequence of its introduction into Ontario nature areas, and a solution for managing its population spread. Finally, it will recommend and propose ideas for the future eradication of V. rossicum on the TNA, and detail the monitored ecological responses therein. 2 2. Introduction 2.1 Assessment and Management of Plant Invasions People who have a keen commitment to environmental issues such as land managers, naturalists, and ecologists, have noticed the rapid infiltration of invasive plants into non-native regions around the world (Sheeley and Raynal 1996; McKague and Cappuccino 2005; Matilla and Otis 2003; Lawlor 2002; Lawlor 2000; Hanrahan 2006; Ladd and Cappuccino 2005; DiTommaso 2005; DiTommaso et al 2005; DiTomasso and Losey 2003; Catling and Mitrow 2005; Casagrande and Dacey, 2007; Cappuccino et al, 2002; Cappuccino, 2004; Abouziena et al 2009). Increased anthropogenic globalization and transport of plants, coupled with activities that cause environmental degradation have combined to cause a rapid increase of non-native plants into historically native ecosystems (Cappuccino et al. 2002; Catling and Mitrow 2005; DiTommaso 2005). These plants typically originate on separate continents where competition in their native ranges limits their success in the ecosystems (Lauvanger and Borgen 1998). However, upon introduction to other regions for horticultural or agricultural purposes, they eventually escape cultivation by seed dispersal, and establish in ecosystems where competition is usually much less than in their native ranges (Lauvanger and Borgen 1998). The term invasive refers to the spread, establishment, and dominance of these plants in ecosystems. The term exotic, that usually follows the term invasive, refers to the alien nature of the plant and its non-native attributes within the environment. Hence, the term invasive exotic plant refers to a plant that originates from another region of the world and has spread its population voraciously in a region that it isn’t inherently native. As the earth’s landscapes and ecosystems become increasingly disturbed by anthropogenic resource exploitation and mass transportation of biological materials cross-continents, many life forms are adapting at an alarmingly fast rate and capitalizing on opportunities to colonize non-native disturbed areas (Catling and Mitrow 2005). Inherently associated with their existence is a strong competitive force that tends to out-compete native plants, thereby displacing food and resources for native species of wildlife. Additionally, plants can cause significant problems for the economy, which include agricultural, fishing, and forestry industries (Havinga 2000). It has been stated by Pimental (1999) that the costs associated with control of only two plants, purple loosestrife (Lythrum salicaria) and melaleuca (melaleuca quinquenervia), have been estimated at $48 million. Because of these reasons, global efforts of assessment and management of invasive exotic plant populations is nearing the critical peak of importance. Luken and Thieret (1997) explain why plant invasions have become so increasingly rampant. They state, “While invasion and range of expansion were indeed a part of the biological history of earth before humans, the rate and scale at which invasions occurred was not similar to that resulting from human activity. The human-caused breakdown of barriers to species dispersal was a global phenomenon and because this had ramifications at all levels 3 of biological invasion from the populations and genes to ecosystems and landscapes, invasions should be recognized as one of the major global environmental issues of our time.” Such an important conservation issue is, unavoidably, requires an extremely complex assemblage of multi-faceted efforts (Havinga 2000). These efforts are first and foremost geared toward prevention of initial and successive plant invasions. These important frontline actions require radical changes in human perception regarding land use practices and transport of exotic plant materials. In situations where exotic plants have already invaded an area, direct and immediate control is necessary but may present an undertaking that is beyond the realm of available resources, depending on the extent to which the plant has established. The most cost- and time-effective strategies should be researched and implemented in any scenario, to provide an efficient management regime for the restoration of a natural area. Entwined within this strategy can be many complications, which lead to controversy over the seemingly contradictive use of certain control methods to restore natural ecosystem integrity, such herbicidal application. The control of invasive exotic plant populations requires the establishment of a detailed strategic framework that incorporates the interests of individuals and institutions with the preservation of natural heritage. Analyzing and researching situations, ordering objectives, developing partnerships, and creating goals for control can all contribute to a collective discussion about proactive steps to take in dealing with problematic and challenging plant invasion scenarios. This discussion should integrate the baseline availability and commitment to the use of available resources. The following strategic plan was adapted from Havinga (2000) and includes eight key strategies. The first four are discussed in this chapter and the final four are discussed in the conclusion chapter. They read as such: 1. Prevention of further introductions In this situation, it is obvious that prevention of invasive plants is the most effective long-term solution for ecological sustainability. Often introduced through the escape from horticultural or agricultural domestication, these plants typically establish and dominate their populations in naturalized environments that have been previously degraded by direct anthropogenic or non- anthropogenic natural processes. As a consequence, the actions of preventing invasions should indeed, focus on minimizing the introductions combined with enacting sustainable environmental practices in order to preserve natural heritage of ecosystems. Some specific actions include: Prevent the use and transport of invasive exotic plant materials in landscaping or horticultural settings near natural areas 4 Develop early warning systems which describe the potential of certain environments to be infiltrated by invasive plants Monitor and manage already-present invasive plants by educating individuals closely associated with managing natural areas Promote the cultivation and naturalization of appropriately-sourced native plants for landscaping and natural areas restoration Promote the conservation of native ecosystem integrity by minimizing disturbance in natural areas 2. Development of strategies for managing target plant species In its current state, there is a growing necessity for research regarding invasive plant management in southern Ontario. However, objective research can be documented and described regarding plant invasion scenarios that have occurred in locations that are similar to the environments of southern Ontario. Some specific actions include: Research and educate the targeted community on priority invasive plants of the region, with an overview of potential guidelines for management regimes Promote the use of the Integrated Pest Management