Growth and Tissue Nitrogen of Epiphytic Atlantic Bryophytes: Effects of Increased and Decreased Atmospheric N Deposition

• Published in: Functional ecology Vol. 18; no. 3; pp. 322 - 329
• Main Authors: Mitchell, R. J., Sutton, M. A., A.-M. Truscott, Leith, I. D., Cape, J. N., Pitcairn, C. E. R., Van Dijk, N.
• Format: Journal Article
• Language: English
• Published: Oxford, UK British Ecological Society 01-06-2004; Blackwell Science Ltd; Blackwell Science
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Atmospherics; Autoecology; Biological and medical sciences; Bryophytes; Dicranum scoparium; Epiphytes; Frullania tamarisci; Fundamental and applied biological sciences. Psychology; General aspects; Human ecology; Isothecium myosuroides; liverworts; mosses; Nitrogen; nitrogen deposition; Plant growth; recovery; Stemflow; Tissue samples; Tissue transplantation; transplant; Transplantation; Ulota crispa; Europe; mosses; Atmospheric fallout; Restoration; Growth; liverworts; nitrogen deposition; Bryophyta; transplant; recovery; Nitrogen; Hepaticae
• ISSN: 0269-8463; 1365-2435
• DOI: 10.1111/j.0269-8463.2004.00828.x

1. Atlantic bryophytes are of European conservation importance, yet the effect on them of excess atmospheric nitrogen is relatively unknown. This study assesses the effects of increased atmospheric N deposition on the growth and tissue N of epiphytic Atlantic bryophytes, and their potential to recover following a decline in N deposition. 2. The N received in stemflow by bryophytes at two sites was measured and compared to model predictions. 3. Four species of epiphytic bryophytes (Isothecium myosuroides, Dicranum scoparium, Frullania tamarisci and Ulota crispa), typical of Atlantic Oak woods, were studied in a 12-month reciprocal transplant experiment between a pristine Oak woodland receiving a modelled atmospheric deposition of 12 kg N ha-1year-1and a polluted one receiving 54 kg N ha-1year-1. 4. Tissue N concentration increased and growth declined following an increase in atmospheric N deposition in all species except Ulota crispa. Conversely, tissue N concentration decreased and growth increased in Frullania tamarisci following a decrease in atmospheric N deposition, with similar non-significant patterns in the other species. 5. The reciprocal transplants indicate a detrimental effect of increased N deposition on the bryophyte species studied. The study indicated recovery following a decrease in atmospheric N deposition, but the responses caused by decreased N deposition were smaller than those due to increased N deposition. This suggests that the time-scale for recovery of bryophytes from excess N deposition is longer than the timescale of nitrogen impacts.