Invasion ecology has suffered from the artificial separation of invasibility and impact processes in understanding the ationship between diversity and plant invasion. By studying these independently functioning stages of invasion in concert, we can gain great insight into the biological causes and consequences of invasions, and develop crucial information for the generation of adequate management strategies. Our conceptual framework provides a structure to synthesize the current body of research, suggests research needed to fill the gaps in understanding and to organize results from future research. The framework is a powerful tool to guide ecological understanding of the relationship between invasion and diversity across systems, species, and scales. The case studies discussed here clearly show how both the cause and consequence of diversity may operate simultaneously hin an invasion to generate the community associations often noted in static studies. Currently, it is not possible to make generalizations about which mechanism is the most important because of the extreme lack of information for most plant invasions. To understand the nature of the relationship between diversity and invasion, both of these processes must be assessed to determine their relative contribution
