Plant succession and species diversity in the Marblehead Quarry, Ohio by Gerald P. Hannes and Susan M. Hannes. Bull. Southern California Acad. Sci., 83(2):90-98, 1984. In three abandoned sites in the Marblehead Quarry, plant species diversity generally increases through time, especially when examined on a vegetation strata basis. The composite diversity value is highest in an intermediately aged community where there is a great degree of habitat heterogeneity due to shading and increased litter and humus content in the soil. Dominance-diversity curves are initially geometric in the earliest successional stage and approach lognormal in the intermediate. That the oldest site does not generally conform to the expected pattern of traditional plant succession is possibly due to a physical characteristic other than time which affects this site and not the other two.