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Measurements of carbon stocks and fluxes in the three major edaphic site types in the La Selva forest (inceptisol terraces, ultisol plateaus, ultisol slopes; 6 0.5 ha plots in each)

Measurement Method Frequency

Aboveground biomass and aboveground biomass increment [in each of the 18 0.5 ha plots] diameter measurement (breast height or above buttresses) of all woody stems > 10 cm in diameter (identified to species) annual

Fine litterfall [in each of the 18 0.5 ha plots] collected in 9 pairs of 0.25 m2 traps per plot; litter sorted into a) leaves, b) fruits, flowers, and other reproductive structures; and c) twigs (wood < 1 cm dia.); oven-dried to constant mass every 2 weeks

Fine woody litterfall [in each of the 18 0.5 ha plots] collected in 9 0.25 m2 traps per plot monthly

Coarse woody debris, standing stocks [in each of the 18 0.5 ha plots] measurement and mapping of all pieces > 30 cm diameter over the entire plot, + of all pieces > 10 cm and <30 cm diameter in 30% of each plot ; all pieces subsampled for measurement of wood density (by water displacement) once, at plot initiation

Coarse woody debris, production [in each of the 18 0.5 ha plots] measurement of all new pieces > 30 cm diameter in the entire plot, and of all new pieces > 10 cm and <30 cm in 30% of the plot annual

Fine root stocks [in each of the 18 0.5 ha plots] 6 soil cores to 50 cm depth, roots removed by agitation in water and hand-sorting into live and dead in 2 size classes: < 2 mm diameter, and 2-<5 mm diameter; oven-dried to constant mass bimonthly

Coarse root stocks (preliminary samples) [in the 6 deep soil shafts, 3 adjacent to ultisol plots & 3 adjacent to inceptisol plots] monoliths (80 cm x 80 cm x 3 m deep) were sieved for all roots > 2 mm in diameter, and sorted (live/dead, 2-<5 mm, 5-<10 mm, 10-<20 mm, >20 mm diameter) from 6 depths (0-10 cm, 10-30 cm, 30-50 cm, 50-100 cm, 100-200 cm, 200-300 cm); dried to constant mass once

Soil respiration (ground surface) [in the 3 ultisol plots & 3 inceptisol plots with deep soil shafts] 5 minute readings with a portable IRGA (Li-6252, logged on a CS CR10x), in 8 surficial chambers/plot every 2 weeks

Soil respiration (down the soil profile) [in the 6 deep soil shafts, 3 adjacent to ultisol plots & 3 adjacent to inceptisol plots] gas samples collected from the soil 1 m in from the shaft walls at depths of .05,.2,.4,.75,1.5,2.5 ,3.5 m; analyzed for CO2 on a Shimadzu gas chromatograph every 2 weeks

Measurement	Method	Frequency
Aboveground biomass and aboveground biomass increment	[in each of the 18 0.5 ha plots] diameter measurement (breast height or above buttresses) of all woody stems > 10 cm in diameter (identified to species)	annual
Fine litterfall	[in each of the 18 0.5 ha plots] collected in 9 pairs of 0.25 m2 traps per plot; litter sorted into a) leaves, b) fruits, flowers, and other reproductive structures; and c) twigs (wood < 1 cm dia.); oven-dried to constant mass	every 2 weeks
Fine woody litterfall	[in each of the 18 0.5 ha plots] collected in 9 0.25 m2 traps per plot	monthly
Coarse woody debris, standing stocks	[in each of the 18 0.5 ha plots] measurement and mapping of all pieces > 30 cm diameter over the entire plot, + of all pieces > 10 cm and <30 cm diameter in 30% of each plot ; all pieces subsampled for measurement of wood density (by water displacement)	once, at plot initiation
Coarse woody debris, production	[in each of the 18 0.5 ha plots] measurement of all new pieces > 30 cm diameter in the entire plot, and of all new pieces > 10 cm and <30 cm in 30% of the plot	annual
Fine root stocks	[in each of the 18 0.5 ha plots] 6 soil cores to 50 cm depth, roots removed by agitation in water and hand-sorting into live and dead in 2 size classes: < 2 mm diameter, and 2-<5 mm diameter; oven-dried to constant mass	bimonthly
Coarse root stocks (preliminary samples)	[in the 6 deep soil shafts, 3 adjacent to ultisol plots & 3 adjacent to inceptisol plots] monoliths (80 cm x 80 cm x 3 m deep) were sieved for all roots > 2 mm in diameter, and sorted (live/dead, 2-<5 mm, 5-<10 mm, 10-<20 mm, >20 mm diameter) from 6 depths (0-10 cm, 10-30 cm, 30-50 cm, 50-100 cm, 100-200 cm, 200-300 cm); dried to constant mass	once
Soil respiration (ground surface)	[in the 3 ultisol plots & 3 inceptisol plots with deep soil shafts] 5 minute readings with a portable IRGA (Li-6252, logged on a CS CR10x), in 8 surficial chambers/plot	every 2 weeks
Soil respiration (down the soil profile)	[in the 6 deep soil shafts, 3 adjacent to ultisol plots & 3 adjacent to inceptisol plots] gas samples collected from the soil 1 m in from the shaft walls at depths of .05,.2,.4,.75,1.5,2.5 ,3.5 m; analyzed for CO2 on a Shimadzu gas chromatograph	every 2 weeks