Nitrogen‐Limited Growth in Plants from Different Successional Stages

The effect of nitrogen availability on the plant growth was studied using nine plant species, some of which are commonly found in recently abandoned old fields while others are more characteristic of native prairie. Each species was grown by itself in nine different soil mixtures in which total soil nitrogen (as N) per unit soil mass ranged from 20 to 850 mg/kg, spanning the range of total soil nitrogen observed in a chronosequence of old fields at Cedar Creek Natural History Area, Minnesota. For each species there was a significant (P < 0.5), positive correlation between the biomass attained after 12 wk of growth and the total soil nitrogen. These data allowed the species to be ranked, from those that attained the greatest biomass as seedling at low nitrogen levels to those that attained the least, as follows: Ambrosia artemisiifolia, Achillea millefolium, Chenopodium album, Agropyron repens, Agrostis scabra, Poa pratensis, Sorghastrum nutans, Schizachyrium scoparium, and Liatris aspera. There was a highly significant tendency for early successional species to grow more rapidly at low nitrogen levels and to acquire more nitrogen per plant from nitrogen—poor soils than late successional species. However, late successional species did not grow more rapidly at high nitrogen levels than early successional species. These results are consistent with the hypothesis that early successional species are dominant following old field abandonment at Cedar Creek because of their ability to compete for soil nitrogen.