Fertilization effects on forest carbon storage and exchange, and net primary production: A new hybrid process model for stand management
A critical ecological question in plantation management is whether fertilization, which generally increases yield, results in enhanced C sequestration over short rotations. We present a rotation-length hybrid process model (SECRETS-3PG) that was calibrated (using control treatments; CW) and verified...
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Published in | Forest ecology and management Vol. 221; no. 1; pp. 91 - 109 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier B.V
01.01.2006
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | A critical ecological question in plantation management is whether fertilization, which generally increases yield, results in enhanced C sequestration over short rotations. We present a rotation-length hybrid process model (SECRETS-3PG) that was calibrated (using control treatments; CW) and verified (using fertilized treatments; FW) using daily estimates of H
2O and CO
2 fluxes, canopy leaf area index (
L), and annual estimates of tree growth and dimension. Herein, we focus on two decades of loblolly pine (
Pinus taeda L.) growth and establishment for stands growing on a nutrient poor, droughty soil (SETRES; Southeast Tree Research and Education Site) in North Carolina, USA, on a site previously occupied by a ∼30-year-old natural long-leaf pine (
P.
palustris Mill.) stand. The SECRETS-3PG model combines: (1) a detailed canopy process model with hourly and daily resolution, (2) a biometrically accurate tree and stand growth module for monthly allocation, 3-PG, and (3) empirical models of soil CO
2 efflux (
R
S). Simulated
L, quadratic mean tree diameter, and total standing biomass all tracked field measurements over a 10-year period. Simulated maintenance respiration, canopy transpiration, and
R
S mirrored, with minor exceptions, short-term independently acquired data. Model correspondence with the independent measurements provided a basis for making short-term estimates of net ecosystem productivity (NEP) and longer-term estimates of net primary production (NPP) over the 20-year period from planting. Simulations suggest that optimum fertilization amendments; (1) increased NEP by more than 10-fold over control – FW (952
g
C
m
−2
a
−1) and CW (71
g
C
m
−2
a
−1) – at maximum NPP and (2) increased NPP two-fold (1334 and 669
g
C
m
−2
a
−1 for FW and CW, respectively) at maximum
L. Seasonal patterns in NEP suggest that autumn and winter may be critical periods for C uptake in nutrient-limited loblolly pine stands. We conclude that increased
L in response to improved nutrition may enable loblolly pine to achieve positive annual NEP earlier in rotation. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0378-1127 1872-7042 |
DOI: | 10.1016/j.foreco.2005.09.010 |