Purple Loosestrife Invasion Analysis in Algonquin Provincial Park, Ontario Natalia Gdula, Shelby Hofstetter, Brianna Horlick

McMaster University, Advanced Raster GIS

The study area is Algonquin Provincial Park in Ontario. This park is located in central Ontario and is susceptible to Purple Loosestrife invasion as it includes many of the preferred habitats of the plant [3].

Criterion Factor Straight

Rank Pairwise

Comparison Rank

Reciprocal

Wetlands Closer is better 1 0.443 0.438

Dams Closer is better (up to 2700m) 2 0.296 0.219

Water Bodies Closer is better (max 900m) 3 0.144 0.146

Water Lines Closer is better (max 900m) 4 0.067 0.109

Roads Closer better (max 540m) 5 0.049 0.088

1. Blossey, B., Skinner , L. C., & Taylor , J. (2001 ). Impact and management of purple loosestrife (lythrum salicaria) in north america . Biodiversity and Conservation, 10, 1787-1807 . Retrieved from http://link.springer.com/article/10.1023/A:1012065703604 2. Kleppel, G. S., & LaBarge, E. (2011). Using sheep to control purple loosestrife (lythrum salicaria). Invasive Plant Science and Management, 4(1), 50-57. doi: 10.1614/IPSM-D-09-00061.1 3. Mullin, B. H. (1998). The biology and management of purple loosestrife (lythrum salicaria). Weed Technology , 12(2), 397-401. 4. Vitousek, P. M., Antonio, C. M., Loope, L. L., Rejmanek, M., & Westbrooks, R. (1997). Introduced species: A significant component of human-caused global change. New Zealand Journal of Ecology , 21(1), 1-16. Retrieved from http://ns.yubawatershed.org/sites/default/files/null/landuse_vitouseketal_1997_invspp_prj.pdf 5. Wilcox, D. (1989). Migration and control of purple loosestrife (lythrum salicaria l.) along highway corridors. Environmental Management , 13(3), 365-370. doi: 10.1007/BF01874916 6. WWF Global. (n.d.) Dam Problems - Environmental Impacts. Retrieved from http://wwf.panda.org/what_we_do/footprint/water/dams_initiative/problems/environmental/ DMTI Spatial- Major Roads and Highways (HRD)(2012), Minor Water Lines (MNWTL)(2012) Ontario Ministry of Natural Resources- Parks and Recreation - Regions (RRP)(2009), Wetland Unit (2011), Ontario Hydro Network (OHN)- Waterbody (2010), Dam and Barrier (2009)

Species invasion is a widespread component of human caused environmental changes [4]. The accidental introduction of Purple Loosestrife (Lythrum salicaria) into North America has had negative impacts on native flora and fauna, especially in wetland ecosystems [1]. The many options for biological and chemical control of Loosestrife populations are not considered plausible for complete eradication of the plant[2] especially once populations have become extensive [3]. Physical controls such as cutting and pulling plants or spot treatments with herbicides can be effective in preventing the spread of Loosestrife or reducing small populations[3] . This demonstrates the importance of early detection of Purple Loosestrife invasion, especially in order to protect conserved ecosystems such as Algonquin Provincial Park.

Figure 1 – Google Maps Image of Algonquin Park location in Ontario.

STUDY AREA

This model was very efficient in determining possible locations of Purple Loosestrife invasion, but further efforts could improve the accuracy of the results. Knowledge of the direction of flow of dammed rivers would be one major improvement, as the habitat would be differentially affected upstream and downstream of the dam, with downstream areas being more susceptible to Loosestrife invasion [6]. Additionally, data for minor roadways within the park were not available, which would have increased the Loosestrife vulnerable areas as it can grow along any road with an adjacent ditch [5].

FACTOR WEIGHTING

Once the pairwise comparison method weightings were applied to the constraint map of Algonquin Park, possible areas for the invasion of Purple Loosestrife were identified. Areas shown in different colours represent different levels of vulnerability to Purple Loosestrife invasion. The results showed 113. 85km2 of highly vulnerable areas (in red) and 1,820.14 km2

of areas with medium vulnerability (in yellow). These presented areas should be monitored closely for Purple Loosestrife in order to prevent an invasion in Algonquin Park.

MODEL IMPROVEMENTS

The sensitivity analysis involved using weightings calculated using a rank reciprocal method instead of a pairwise comparison method. The results, seen above showed that there were no significant discrepancies between the two methods, demonstrating that this model produced accurate results.

BACKGROUND

SENSITIVITY ANALYSIS

REFERENCES/DATA SOURCES RESULTS AND RECOMENDATIONS

DECISION RULE

Constraint Reasoning

Water Bodies Cannot be in water

Roads Cannot grow on roads

Minor Waterlines Cannot be in water

Park Boundary Must be within park boundary