TY - JOUR
T1 - Heterotrophic respiration and the divergence of productivity and carbon sequestration
AU - Noormets, Asko
AU - Bracho, Rosvel
AU - Ward, Eric
AU - Seiler, John
AU - Strahm, Brian
AU - Lin, Wen
AU - McElligott, Kristin
AU - Domec, Jean-Christophe
AU - Gonzalez-Benecke, Carlos
AU - Jokela, Eric J.
AU - Markewitz, Daniel
AU - Meek, Cassandra
AU - Miao, Guofang
AU - McNulty, Steve G.
AU - King, John S.
AU - Samuelson, Lisa
AU - Sun, Ge
AU - Teskey, Robert
AU - Vogel, Jason
AU - Will, Rodney
AU - Yang, Jinyan
AU - Martin, Timothy A.
PY - 2021
Y1 - 2021
N2 - Net primary productivity (NPP) and net ecosystem production (NEP) are often used interchangeably, as their difference, heterotrophic respiration (soil heterotrophic CO2 efflux, RSH = NPP− NEP), is assumed a near-fixed fraction of NPP. Here, we show, using a range-wide replicated experimental study in loblolly pine (Pinus taeda) plantations that RSH responds differently than NPP to fertilization and drought treatments, leading to the divergent responses of NPP and NEP. Across the natural range of the species, the moderate responses of NPP (+11%) and RSH (−7%) to fertilization combined such that NEP increased nearly threefold in ambient control and 43% under drought treatment. A 13% decline in RSH under drought led to a 26% increase in NEP while NPP was unaltered. Such drought benefit for carbon sequestration was nearly twofold in control, but disappeared under fertilization. Carbon sequestration efficiency, NEP:NPP, varied twofold among sites, and increased up to threefold under both drought and fertilization.
AB - Net primary productivity (NPP) and net ecosystem production (NEP) are often used interchangeably, as their difference, heterotrophic respiration (soil heterotrophic CO2 efflux, RSH = NPP− NEP), is assumed a near-fixed fraction of NPP. Here, we show, using a range-wide replicated experimental study in loblolly pine (Pinus taeda) plantations that RSH responds differently than NPP to fertilization and drought treatments, leading to the divergent responses of NPP and NEP. Across the natural range of the species, the moderate responses of NPP (+11%) and RSH (−7%) to fertilization combined such that NEP increased nearly threefold in ambient control and 43% under drought treatment. A 13% decline in RSH under drought led to a 26% increase in NEP while NPP was unaltered. Such drought benefit for carbon sequestration was nearly twofold in control, but disappeared under fertilization. Carbon sequestration efficiency, NEP:NPP, varied twofold among sites, and increased up to threefold under both drought and fertilization.
UR - https://hdl.handle.net/1959.7/uws:64700
U2 - 10.1029/2020GL092366
DO - 10.1029/2020GL092366
M3 - Article
SN - 0094-8276
VL - 48
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 7
M1 - e2020GL092366
ER -