Count-list and chart quadrats, camera-sets-frequence and frequence-abundance determinations were used to compare the vegetation of 28 fields in Story and Boone counties during the first growing season following cultivation. Similarities and differences in growth response as well as in floristics were tabulated and evaluated. There seemed to be little relationship between the frequency and constancy of the species and previous cultural treatment although there was a definite relationship between their abundance and previous cultural treatment. By the end of August, in the drought year of 1934, sufficient top cover had developed to reduce to an appreciable degree the force of the rain water falling on the areas: 34.5 per cent cover to 91 per cent cover with an average of 58 per cent. Annuals which are effective aggregates because of abundance of non-motile seed and ease of establishment (Setaria viridis, Setaria glauca and Ambrosia trifida) were found to be dominant in most of the communities the first year. Setaria viridis had greater frequence and frequence-abundance than any other species although several of the species have more seeds per plant.
Proceedings of the Iowa Academy of Science
©1939 Iowa Academy of Science, Inc.
Aikman, J. M. and Barr, Helen F.
"A Quantitative Study of the Early Weed Stage of Secondary Plant Succession in Central Iowa,"
Proceedings of the Iowa Academy of Science, 46(1), 179-179.
Available at: https://scholarworks.uni.edu/pias/vol46/iss1/21