Abstract
Soil carbon (C) pools and plant community composition are regulated by nitrogen (N) and phosphorus (P) availability. Atmospheric N deposition impacts ecosystem C storage, but the direction of response varies between systems. Phosphorus limitation may constrain C storage response to N, hence P application to increase plant productivity and thus C sequestration has been suggested. We revisited a 23-yr-old field experiment where N and P had been applied to upland heath, a widespread habitat supporting large soil C stocks. At 10 yr after the last nutrient application we quantified long-term changes in vegetation composition and in soil and vegetation C and P stocks. Nitrogen addition, particularly when combined with P, strongly influenced vegetation composition, favouring grasses over Calluna vulgaris, and led to a reduction in vegetation C stocks. However, soil C stocks did not respond to nutrient treatments. We found 40% of the added P had accumulated in the soil. This study showed persistent effects of N and N + P on vegetation composition, whereas effects of P alone were small and showed recovery. We found no indication that P application could mitigate the effects of N on vegetation or increase C sequestration in this system.
Original language | English |
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Pages (from-to) | 226-237 |
Number of pages | 12 |
Journal | New Phytologist |
Volume | 228 |
Issue number | 1 |
Early online date | 24 Jun 2020 |
DOIs | |
Publication status | Published - Oct 2020 |
Keywords
- long-term
- nitrogen deposition
- nutrient cycling
- upland heath
- soil
- vegetation
- long term
- DEPOSITION INCREASES
- NUTRIENT LIMITATION
- VASCULAR PLANTS
- RESPONSES
- COMMUNITY STRUCTURE
- MICROBIAL BIOMASS
- SPHAGNUM
- LITTER
- LONG-TERM NITROGEN
- ATMOSPHERIC NITROGEN