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Title: Duke FACE -- Forest-Atmosphere Carbon Transfer and Storage (FACTS I)

Technical Report ·
DOI:https://doi.org/10.2172/1237078· OSTI ID:1237078
 [1]
  1. Duke Univ., Durham, NC (United States)

The Duke FACE experiment increases atmospheric [CO2] to a height of 25 m in four 30-m diameter plots, each containing ~100 canopy trees and many sub-canopy individuals. The experiment was initiated in 1994 with CO2 fumigation of the prototype plot, and reached full CO2-fumigation capacity in 1996 when three additional FACE plots came on line. All elevated plots enriched the atmospheric CO2 concentration by 200 ppmv relative to paired, ambient-CO2 plots. Formalizing the analysis of CO2 x N interactions, in March of 2005 each of the six FACE plots established in 1996 was trenched in half, and one half plot fertilized with nitrogen (N) at a rate of 11 g m-2 yr-1, following the approach established in 1998 in the prototype and its reference plot. The δ 13C of the fumigated plots’ atmosphere was -42.6‰, and while the 15N of the fertilizer did not affect the δ 15N of tissues directly it greatly reduced the effect of a 15N tracer study on tissue δ 15N. The CO2 enrichment was completed in early November, 2010. Prior to termination of fumigation, 1-8 branches from 4-5 Pinus taeda individuals in each half plot were harvested, as well as most Juniperus occidentalis and broadleaved individuals <2 cm in diameter (1.4 m aboveground), including vine and herbaceous individuals. Following the termination, all individuals <8 cm in diameter, followed by all remaining individuals were harvested in half of each plot (a quarter in each CO2 X N treatment). In all, 189 m3 of dry material and 826 m3 of wet material, or a total of 1014 m3 of material is stored in various suited settings. The project quantified the effect of CO2 X N on carbon uptake, allocation to various pools, accumulation of carbon in these pools, the release of carbon to the atmosphere, and factors controlling these processes. The project also assessed the effect of CO2 X N on the components of the water budget, and related processes, as well as on the amount and diversity of understory vegetation.

Research Organization:
Duke Univ., Durham, NC (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
FG02-95ER62083
OSTI ID:
1237078
Report Number(s):
DOE-DUKE-62083
Country of Publication:
United States
Language:
English