8Pimentel D, Zuniga R, Morrison D. 2005. Update on the environmental and economic costs associated with alieninvasivespecies in the United States. Ecological Economics, 52:273-288.
9Rudgers JA, Orr S. 2009. Nonnative grass alters growth ofnative tree species via leaf and soil microbes. Journal ofEcology, 97: 247-255.
10Williamson M. 1996. Biological Invasions. London: Chapman& Hall.