Johansson, Otilia
- Umeå Universitet
Sammanfattning
P>Here, we examined the responses of the epiphytic lichens Alectoria sarmentosa and Platismatia glauca to increased atmospheric nitrogen (N) deposition in an old-growth boreal spruce forest, to assess the sensitivity of these species to N and define their critical N load.Nitrogen deposition was simulated by irrigating 15 trees over a 3 yr period with water and isotopically labeled NH(4)NO(3), providing N loads ranging from ambient to 50 kg N ha-1 yr-1.Thallus N concentration increased in both species with increasing N load, and uptake rates of both NH(4)+ and NO(3)- were similar. Photobiont concentration increased linearly with increased N in both species, saturating in A. sarmentosa in the third year at the highest N loads (25 and 50 kg ha-1 yr-1). The simulated N deposition decreased the phosphorus (P) concentration in A. sarmentosa, and increased the N : P ratio in both species.Significant responses in lichen chemistry were detected to inputs of 12.5 kg N ha-1 yr-1 or higher, suggesting that resources other than N limit lichens at higher N loads. However, the data also suggest that N saturation may be cumulative over time, even at low N.
Nyckelord
15N-labeled ammonium nitrate; Alectoria sarmentosa; Chla; critical load; lichen sensitivity; phosphorus; Platismatia glauca; simulated nitrogen deposition
Publicerad i
New Phytologist
2010, volym: 188, nummer: 4, sidor: 1075-1084
Utgivare: WILEY-BLACKWELL PUBLISHING, INC
SLU författare
Nordin, Annika
- Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
- Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
UKÄ forskningsämne
Skogsvetenskap
Publikationens identifierare
- DOI: https://doi.org/10.1111/j.1469-8137.2010.03426.x
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/59500