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

Oren, Ram¹ 

[1] Duke Univ., Durham, NC (United States)

关键词: Carbon Sequestration;    Climate Change;    CO2 enrichment;    Ecophysiology;    Forest Growth;    Gas Exchange;    Respiration;    Soil Processes;    Species Responses;    Stomatal Response;    Transpiration;    Understory;    Water-use;   

DOI  :  10.2172/1237078
RP-ID  :  DOE-DUKE--62083
PID  :  OSTI ID: 1237078

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

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 ?? ¹³C of the fumigated plots??? atmosphere was -42.6??��, and while the ¹⁵N of the fertilizer did not affect the ?? ¹⁵N of tissues directly it greatly reduced the effect of a ¹⁵N tracer study on tissue ?? 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.