Are we experiencing an invasional meltdown?. They found that the invasional meltdown hypothesis had the highest level of support among the six. Invasional meltdown, where established non-indigenous species facilitate the establishment and spread of newly arriving non-indigenous species, may contribute t Positive Interactions of Nonindigenous Species: Invasional Meltdown? Daniel Simberloff Affiliated with Department of Ecology and Evolutionary Biology. Invasional meltdown: invader-invader mutualism facilitates a secondary invasion. The invasional meltdown hypothesis (IMH). The invasional meltdown hypothesis (IMH). Invasional meltdown: Invader–invader mutualism facilitates a secondary invasion. Ecology 92:1758–1768. invasional meltdown hypothesis (IMH). September 2011 INVADER MUTUALISM AND SECONDARY INVASION 1759. The response variable (Oj,t) was the appearance of land INVASIONAL MELTDOWN 361 it was found that native herbivores suppressed nonnative plants, while nonindigneous herbivores facilitated both the abundance and species. Mutational meltdown (not to be confused with the concept of an error catastrophe [1]) is the accumulation of harmful mutations in a small population, which leads to. Ecology/Invasive species. This phenomenon is termed invasional cartels. One illustration of the meltdown hypothesis is the invasion of the great lakes by. Experimental test of the Invasional Meltdown Hypothesis: an exotic herbivore facilitates an exotic plant, but the plant does not reciprocally facilitate the herbivore.