XVI International Botanical Congess

We have surveyed 60 species of pteridophytes, representing various phylogenetic groups and ecological habits, for foliar nitrogen concentration. Significantly higher percentages of nitrogen were found in mature as compared to dead leaf tissue among these species. The concentrations of nitrogen in our samples were within the range found for other vascular plants. However, the average percent of nitrogen retranslocated from senescing leaf tissue appears to be much lower in pteridophytes than previous studies have found in angiosperms and conifers. Surprisingly, we find no significant difference in nitrogen concentration between sterile and fertile samples. Furthermore, the evolutionary and ecological significance of nitrogen retranslocation in pteridophytes is discussed.