Contrasting effects of long term versus short-term nitrogen addition on photosynthesis and respiration in the Arctic Journal Article


Authors: van de Weg, Martine J.; Shaver, Gaius R.; Salmon, Verity G.
Article Title: Contrasting effects of long term versus short-term nitrogen addition on photosynthesis and respiration in the Arctic
Abstract: We examined the effects of short ( 25 %) in both species after 22 years of N addition, but not in the shorter-term treatments. Surprisingly, Chl only increased in both species the first year of fertilisation (i.e. the first season of nutrients applied), but not in the longer-term treatments. These results imply that: (1) under current (low) N availability, these Arctic species either already optimize their photosynthetic capacity per leaf area, or are limited by other nutrients; (2) observed increases in Arctic NEE and GPP with increased nutrient availability are caused by structural changes like increased leaf area index, rather than increased foliar photosynthetic capacity and (3) short-term effects (1-4 years) of nutrient addition cannot always be extrapolated to a larger time scale, which emphasizes the importance of long-term ecological experiments.
Keywords: ALASKA; CO2 FLUX; TUSSOCK TUNDRA; NUTRIENT ADDITION; ALASKAN TUNDRA; GAS-EXCHANGE; SOIL RESPIRATION; LEAF-AREA; WET SEDGE TUNDRA; CHLOROPHYLL; LTER; CANOPY; fertilisation; LIMITED PHOTOSYNTHESIS; Leaf mass per area; Nitrogen use efficiency; TEMPERATURE RESPONSE FUNCTIONS
Journal Title: Plant Ecology
Volume: 214
Issue: 10
ISSN: 1385-0237
Publisher: Springer Verlag  
Publication Place: DORDRECHT; VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
Date Published: 2013
Start Page: 1273
End Page: 1286
DOI/URL:
Notes: PT: J; TC: 0; UT: WOS:000324498500007