The successional dynamics of sand dune systems provide an opportunity to examine how non-native plant species affect plant communities over small spatial scales. We investigated the status of non-native pine species introduced as seeds about 130 years ago at Illinois Beach State Park, Illinois (IBSP). Five patchy stands of Pinus nigra (Austrian pine) were found and studied (spatial relations, age by dendrochronology, diameter, nearest neighbor distance) to reconstruct the invasion process. Pinus nigra forms limited age range stands. Recruitment is episodic not only in time but also spatially. Each P. nigra age class stand is associated with significantly different ground layer vegetation categories that are different from each other as well as from the nearby sand prairie areas. Woody plant ground layer vegetation increased progressively as pine stands matured. This progressive temporal change with stand age is also reflected in a significant effect of distance from a tree on ground layer vegetation categories. Specifically, the frequency of woody vegetation is significantly greater at close (1 m) distance from trunks than at 5 or 10 m distances. Graminoid and forb ground cover decreased significantly and progressively with pine stand age and distance from pine trees. This introduced, non-native tree species has significantly altered the dune vegetation at IBSP. This study is a rare assessment of the community-level effects of an invasive species over a century after its introduction.