Evaluation of Invasion Risk Levels with Symmetrically Distributed Linguistic Terms Sets

This chapter evaluates overall invasion risk that emerges from biological traits of IAPS. The following eight parameters have been selected as the model parameters: number of seeds per fruit, Annual seed production per m², viability of seeds, long distance dispersal strength, vegetative reproduction strength, seed germination requirement level, potential to be spread by human activities and role of natural and man-made disturbances. When selecting the appropriate linguistic terms set, performance values of the parameters and the nature of the output have to be considered. It introduces a new weight vector to weight the performance values of main/sub parameters. The approximation approach procedure has been carried out using the numerical-linguistic transformation function.