A comparison of levels of herbivory, morph frequency, soil moisture, soil type, average heights, and density in Lythrum salicaria populations of different levels of invasion.

I examined the invasive tristylous plant Lythrum salicaria in high and low levels of invasion. The high invasion areas are not in a 1:1:1 morph equilibrium. The areas of low invasion do fit this expected equilibrium. More same-same morph nearest neighbor pairs was found in both levels then expected. The proportion of seedlings does not vary between high and low levels of invasion. In high levels of invasion the adult L. salicaria plants have 1/3 more inflorescences than the adults in the low level of invasion. As the average height of the adult plants increases the number of inflorescences increases. There is no difference between the morphs in the average number of inflorescences and in the average height. The average height of the morphs is higher in areas of high invasion, than in low invasion. Higher herbivory occurs in areas of higher invasion, but in response a higher number of inflorescences per stem is produced. This leads to greater sexual reproduction most likely in areas of high invasion. Populations in high invasion levels tend to be in organic soil that is damp or saturated, while populations in lower invasion levels are in organic to a mixture of organic and mineral soil, that is damp or dry.http://deepblue.lib.umich.edu/bitstream/2027.42/54951/1/3392.pdfDescription of 3392.pdf : Access restricted to on-site users at the U-M Biological Station