Legacy effects of nitrogen and phosphorus additions on vegetation and carbon stocks of upland heaths. Issue 1 (24th June 2020)

• Record Type: Journal Article
• Authors: van Paassen, José G.; Britton, Andrea J.; Mitchell, Ruth J.; Street, Lorna E.; Johnson, David; Coupar, Andrew; Woodin, Sarah J.
• Is Part Of: New phytologist. Volume 228:Issue 1(2020)
• Page Start: 226
• Page End: 237
• Publication Date: 2020-06-24
• Subjects: long term -- nitrogen deposition -- nutrient cycling -- soil -- upland heath -- vegetation; Botany -- Periodicals; 580
• DOI: 10.1111/nph.16671
• Languages: English
• ISSNs: 0028-646X

Abstract

Summary: 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.