Abstract
•Arctic ecosystems are strongly nutrient limited and exhibit dramatic responses to nitrogen (N) enrichment, the reversibility of which is unknown. This study uniquely assesses the potential for tundra heath to recover from N deposition and the influence of phosphorus (P) availability on recovery.
•We revisited an experiment in Svalbard, established in 1991, in which N was applied at rates representing atmospheric N deposition in Europe (10 and 50 kg N ha−1 yr−1; ‘low’ and ‘high’, respectively) for 3–8 yr. We investigated whether significant effects on vegetation composition and ecosystem nutrient status persisted up to 18 yr post-treatment.
•Although the tundra heath is no longer N saturated, N treatment effects persist and are strongly P-dependent. Vegetation was more resilient to N where no P was added, although shrub cover is still reduced in low-N plots. Where P was also added (5 kg P ha−1 yr−1), there are still effects of low N on community composition and nutrient dynamics. High N, with and without P, has many lasting impacts. Importantly, N + P has caused dramatically increased moss abundance, which influences nutrient dynamics.
•Our key finding is that Arctic ecosystems are slow to recover from even small N inputs, particularly where P is not limiting.
| Original language | English |
|---|---|
| Pages (from-to) | 682-695 |
| Number of pages | 14 |
| Journal | New Phytologist |
| Volume | 206 |
| Issue number | 2 |
| Early online date | 19 Jan 2015 |
| DOIs | |
| Publication status | Published - Apr 2015 |
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Keywords
- bryophytes
- critical load
- nitrogen (N) deposition
- phosphorus (P)
- recovery
- tundra
- winter injury
Cite this
Slow recovery of High Arctic heath communities from nitrogen enrichment. / Street, Lorna E.; Burns, Nancy R.; Woodin, Sarah J.
In: New Phytologist, Vol. 206, No. 2, 04.2015, p. 682-695.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Slow recovery of High Arctic heath communities from nitrogen enrichment
AU - Street, Lorna E.
AU - Burns, Nancy R.
AU - Woodin, Sarah J.
N1 - Acknowledgements We are indebted to Ian Alexander who initiated the fertilisation experiment with SJW; to successive researchers involved in the experiment, John Baddeley, Nanette Madan, Lars Hogbom, Bernard Moyersen, Carmen Gordon; and to field assistants, Alison Horsburgh, Andrew Coughlan, Jo Wynn, Lora Crabtree. We thank Hans Kruijer and Michael Stech for assistance with bryophyte species identification in 2011. Funding for the initial experiment was provided by the NERC Arctic Terrestrial Ecology Special Topic Programme (GR3/9424, GR9/3433) with additional support from the CEC TMR Programme, Ny-Ålesund LSF and the British Ecological Society. This recovery study was funded by NERC (NE/I016899/1). The research was made possible by use of NERC facilities at Harland Huset; special thanks to Nick Cox and colleagues for their unfailing hospitality and support.
PY - 2015/4
Y1 - 2015/4
N2 - Summary•Arctic ecosystems are strongly nutrient limited and exhibit dramatic responses to nitrogen (N) enrichment, the reversibility of which is unknown. This study uniquely assesses the potential for tundra heath to recover from N deposition and the influence of phosphorus (P) availability on recovery.•We revisited an experiment in Svalbard, established in 1991, in which N was applied at rates representing atmospheric N deposition in Europe (10 and 50 kg N ha−1 yr−1; ‘low’ and ‘high’, respectively) for 3–8 yr. We investigated whether significant effects on vegetation composition and ecosystem nutrient status persisted up to 18 yr post-treatment.•Although the tundra heath is no longer N saturated, N treatment effects persist and are strongly P-dependent. Vegetation was more resilient to N where no P was added, although shrub cover is still reduced in low-N plots. Where P was also added (5 kg P ha−1 yr−1), there are still effects of low N on community composition and nutrient dynamics. High N, with and without P, has many lasting impacts. Importantly, N + P has caused dramatically increased moss abundance, which influences nutrient dynamics.•Our key finding is that Arctic ecosystems are slow to recover from even small N inputs, particularly where P is not limiting.
AB - Summary•Arctic ecosystems are strongly nutrient limited and exhibit dramatic responses to nitrogen (N) enrichment, the reversibility of which is unknown. This study uniquely assesses the potential for tundra heath to recover from N deposition and the influence of phosphorus (P) availability on recovery.•We revisited an experiment in Svalbard, established in 1991, in which N was applied at rates representing atmospheric N deposition in Europe (10 and 50 kg N ha−1 yr−1; ‘low’ and ‘high’, respectively) for 3–8 yr. We investigated whether significant effects on vegetation composition and ecosystem nutrient status persisted up to 18 yr post-treatment.•Although the tundra heath is no longer N saturated, N treatment effects persist and are strongly P-dependent. Vegetation was more resilient to N where no P was added, although shrub cover is still reduced in low-N plots. Where P was also added (5 kg P ha−1 yr−1), there are still effects of low N on community composition and nutrient dynamics. High N, with and without P, has many lasting impacts. Importantly, N + P has caused dramatically increased moss abundance, which influences nutrient dynamics.•Our key finding is that Arctic ecosystems are slow to recover from even small N inputs, particularly where P is not limiting.
KW - bryophytes
KW - critical load
KW - nitrogen (N) deposition
KW - phosphorus (P)
KW - recovery
KW - tundra
KW - winter injury
U2 - 10.1111/nph.13265
DO - 10.1111/nph.13265
M3 - Article
VL - 206
SP - 682
EP - 695
JO - New Phytologist
JF - New Phytologist
SN - 0028-646X
IS - 2
ER -