What is an enrichment protocol? Solution solution: 1)The FACE system was designe

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What is an enrichment protocol?

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solution: 1)The FACE system was designed to permit the experimental exposure of tall vegetation such as stands of forest trees to elevated atmospheric CO2 concentrations ([CO2]) without enclosures that alter tree microenvironment. The FACE approach permits the study of a wide range of forest stand and ecosystem processes under elevated CO2 that were previously impossible or intractable to study in true forest ecosystems. The system provides spatial and temporal control of [CO2] similar to that reported for open-top chambers over trees, but without enclosing the vegetation. Each system uses feedback control technology to control [CO2] in a 30 m diameter forest plot that is over 16 m tall, while monitoring the 3D plot volume to characterize the whole-stand CO2 regime achieved during enrichment. The FACE system provides atmospheric CO2 enrichment with a preset [CO2] target of 200 µmol mol-1 above ambient [CO2]. At the control points [CO2] averaged among the three CO2 enrichment plots over all of the year 2000 was 199.7 µmol mol-1 above the ambient atmospheric CO2 concentration of 382 µmol mol-1, or 582 µmol mol-1. Temporal control of [CO2] is very good: The 1-min. average [CO2] was within ±20% of the intended concentration (ambient [CO2] plus 200 µmol mol-1) >91% of the time, and within ±10% of the intended concentration >67% of the time. Deviations of [CO2] outside of this range are short-lived (most lasting < 60 s) and rare, with less than 0.5% of excursion events of a minute or longer per day. The spatial control of [CO2] by the system maintains annual average [CO2] for >90% of the entire canopy volume to within ± 10% of the target. CO2 enrichment for the plots operating since 1996 was provided 24 hours per day when air temperature is above 5° C and wind speed is below 5 m/s. In 2003, this was changed to daytime-only enrichment, similar to the enrichment in the prototype plot since its inception, and at the same time CO2 enrichment schedule in the prototype plot, which until that year entirely ceased during the non-growing season, was made similar to that of the other plots, ceasing only when air temperature is 5 m s-1. Interruption of this schedule (unscheduled down-time due to severe weather or failures of equipment or control systems) occurred rarely, resulting in system performance reliability of 99%. These performance metrics are typical of FACE experiments for sites using BNL-designed FACE equipment. For a complete technical description of the prototype system, see Hendrey et. al. (1999). 2) Protocol for micro-purification, enrichment, pre-fractionation and storage of peptides for proteomics using StageTips

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