Nitrogen limitation in a sweetgum plantation: implications for carbon allocation and storage

2008 ◽  
Vol 38 (5) ◽  
pp. 1021-1032 ◽  
Author(s):  
Colleen M. Iversen ◽  
Richard J. Norby
Keyword(s):  
Primary Production ◽  
Fine Root ◽  
Net Primary Production ◽  
Root Production ◽  
N Availability ◽  
Fine Root Production ◽  
Wood Production ◽  
N Limitation ◽  
Face Experiment ◽  
Leaf N

The N status of temperate forests is closely linked to their C fluxes, and altered C or N availability may affect ecosystem C storage through changes in forest production and C allocation. We proposed that increased fine-root production previously observed in a sweetgum ( Liquidambar styraciflua L.) forest in response to elevated [CO2] was a physiological response to N limitation. To examine this premise, we fertilized plots in the sweetgum plantation adjacent to the Oak Ridge National Laboratory free-air CO2-enrichment (FACE) experiment. We hypothesized that N fertilization would increase sweetgum net primary production, leaf [N], and the relative flux of C to wood production. Annual additions of 200 kg·ha–1 of N as urea increased soil N availability, which increased stand net primary production, stand N uptake, and N requirement by about one-third. Increased leaf [N] and leaf area production in the fertilized plots increased stem production and shifted relative flux of C to wood production. We conclude that sweetgum production on this site is limited by soil N availability and a decreased fraction of net primary production in fine-root production with N addition is consistent with the premise that increased fine-root production in the adjacent FACE experiment is in response to N limitation.

Biomass distribution and above- and below-ground production in young and mature Abiesamabilis zone ecosystems of the Washington Cascades

1981 ◽  
Vol 11 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Charles C. Grier ◽  
Kristiina A. Vogt ◽  
Michael R. Keyes ◽  
Robert L. Edmonds
Keyword(s):  
Primary Production ◽  
Fine Root ◽  
Net Primary Production ◽  
Root Production ◽  
Fine Root Production ◽  
Biomass Distribution ◽  
Net Production ◽  
Young Stand ◽  
Mature Stand ◽  
Below Ground

Biomass distribution and above- and below-ground net primary production were determined for 23- and 180-year-old Abiesamabilis (Dougl.) Forbes ecosystems growing at 1200-m elevation in the western Washington Cascade Range. Total organic matter accumulations were 427.0 t•ha−1 in the young stand, and 1247.1 t•ha−1 in the mature stand. Aboveground tree and detritus biomass were 49.0 t•ha−1 and 130.2 t•ha−1, respectively, in the young stand compared with 445.5 t•ha−1 and 389.4 t•ha−1 in the mature stand. Net primary production (NPP) was 18.3 t•ha−1 in the young stand and 16.8 t•ha−1 in the mature stand. Belowground dry matter production was 65% of total net production in the young stand and 73% of total net production in the mature stand. Conifer fine root production was 35.9% of NPP in the young and 66.4% of NPP in the mature stand. This apparent shift in fine root production as a proportion of NPP may be related to detritus accumulation.

scholarly journals A global analysis of fine root production as affected by soil nitrogen and phosphorus

2012 ◽  
Vol 279 (1743) ◽  
pp. 3796-3802 ◽  
Author(s):  
Z. Y. Yuan ◽  
Han Y. H. Chen
Keyword(s):  
Fine Root ◽  
Net Primary Production ◽  
Global Analysis ◽  
Terrestrial Ecosystems ◽  
Root Production ◽  
Fine Root Production ◽  
Soil N ◽  
Natural Habitats ◽  
Global Average ◽  
P Addition

Fine root production is the largest component of belowground production and plays substantial roles in the biogeochemical cycles of terrestrial ecosystems. The increasing availability of nitrogen (N) and phosphorus (P) due to human activities is expected to increase aboveground net primary production (ANNP), but the response of fine root production to N and P remains unclear. If roots respond to nutrients as ANNP, fine root production is anticipated to increase with increasing soil N and P. Here, by synthesizing data along the nutrient gradient from 410 natural habitats and from 469 N and/or P addition experiments, we showed that fine root production increased in terrestrial ecosystems with an average increase along the natural N gradient of up to 0.5 per cent with increasing soil N. Fine root production also increased with soil P in natural conditions, particularly at P < 300 mg kg −1 . With N, P and combined N + P addition, fine root production increased by a global average of 27, 21 and 40 per cent, respectively. However, its responses differed among ecosystems and soil types. The global average increases in fine root production are lower than those of ANNP, indicating that above- and belowground counterparts are coupled, but production allocation shifts more to aboveground with higher soil nutrients. Our results suggest that the increasing fertilizer use and combined N deposition at present and in the future will stimulate fine root production, together with ANPP, probably providing a significant influence on atmospheric CO 2 emissions.

Estimating fine-root production and turnover from biomass and decomposition data: a compartment–flow model

1987 ◽  
Vol 17 (8) ◽  
pp. 900-908 ◽  
Author(s):  
D. Santantonio ◽  
J. C. Grace
Keyword(s):  
Soil Temperature ◽  
Fine Roots ◽  
Flow Model ◽  
Fine Root ◽  
Net Primary Production ◽  
Independent Set ◽  
Early Summer ◽  
Root Decomposition ◽  
Root Production ◽  
Fine Root Production

Production and replacement of fine roots (diam. < 1 mm) takes 8–67% of net primary production in forests. Most of this production is lost through mortality; little appears as an increment. Traditional biomass methods underestimate fine-root production because estimating production or mortality from changes in standing crop alone does not adequately account for simultaneous and compensating processes of growth, death, and replacement which occur continuously. We propose a compartment–flow model to solve this problem and estimate fine-root production and mortality at a monthly resolution for a pine plantation in New Zealand. The main component of the model is fine-root decomposition, an exponential decay function driven by soil temperature. The model "produces" and "turns over" enough fine roots to maintain observed standing crops of live and dead fine roots given losses through decomposition each month. We have formulated the model as differential and difference equations. Monthly estimates from the model indicated smooth modal patterns. Production and mortality peaked in early spring (September) at about 600 kg•ha−1•month−1 and fell to near zero in summer (January–February). The periodicity of these two processes was out of phase with soil temperature at 10 cm. Decomposition occurred continuously; it peaked in early summer (December) and declined to low levels during winter and was in phase with soil temperature. In a validation of the decomposition portion of the model with an independent set of decomposition data, measured standing crops of dead fine root were not statistically different from predicted values.

Heterorhizy can lead to underestimation of fine-root production when using mesh-based techniques

2014 ◽  
Vol 59 ◽  
pp. 84-90 ◽  
Author(s):  
A. Montagnoli ◽  
M. Terzaghi ◽  
G.S. Scippa ◽  
D. Chiatante
Keyword(s):  
Fine Root ◽  
Root Production ◽  
Fine Root Production

Fine root production and litter input: Its effects on soil carbon

2005 ◽  
Vol 272 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
L. B. Guo ◽  
M. J. Halliday ◽  
S. J. M. Siakimotu ◽  
R. M. Gifford
Keyword(s):  
Soil Carbon ◽  
Fine Root ◽  
Root Production ◽  
Fine Root Production ◽  
Litter Input

Fine root mass and fine root production in tropical moist forests as dependent on soil, climate, and elevation

2011 ◽  
pp. 428-444 ◽  
Author(s):  
D. Hertel ◽  
Ch. Leuschner ◽  
L. A. Bruijnzeel ◽  
F. N. Scatena ◽  
L. S. Hamilton
Keyword(s):  
Fine Root ◽  
Root Production ◽  
Fine Root Production ◽  
Root Mass ◽  
Soil Climate
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