Watershed 5 1983 Quantitative Pit Soil Carbon And Nitrogen

TITLE
Watershed 5 1983 Quantitative Pit Soil Carbon And Nitrogen

PRINCIPAL INVESTIGATOR
       Douglas F. Ryan
       Morris Arboretum
       9414 Meadowbrook Ave.
       Philadelphia, Pa 19118
       (215) 247-5777

OTHERS INVOLVED
Hamburg
Huntington

BEGIN DATE
July 1983

END DATE
August 1983

LOCATION
Watershed 5

LOCATION DESCRIPTION
60 pits were located in stratified random fashion in 6 elevation bands on W5. 25x25m plots containing individual pits are identified in the HB grid system by "pit number" in the data set.

DATA DESCRIPTION
Soil carbon and nitrogen concentrations and pools in forest floor horizons and mineral soil depth strata in 60 quantitative pits on W5 before whole tree harvest.

SAMPLING DESIGN
Our objective was to measure soil carbon and nitrogen pools and concentrations before whole tree harvesting as a baseline from which to estimate changes in pools after harvest. A 71x71cm frame was fastened to soil surface. Combined Oi and Oe horizons, the Oa horizon and 0-10cm, 10-20cm and 20cm to bottom of B horizon depth strata in mineral soil were excavated quantitatively. The volume, in situ, and mass of each layer were measured in the field. Subsamples of soil were collected for lab analysis.

LABORATORY PROCEDURES
Forest floor was sieved to 6.25mm. Mineral soil was sieved to 2mm. C and N were measured on an automated C-N analyzer (NA-1500 Erba Instruments, Peabody, MA) employing modified Dumas combustion and gas chromatography.

CALCULATIONS
Pool sizes of C and N were calculated by multiplying the concentration of an element in a horizon or stratum by the dry (105 deg.C) mass of the sieved soil in that depth stratum or horizon.

REFERENCES

Huntington, T. G., D. F. Ryan and S. P. Hamburg. 1988. Estimating soil nitrogen and carbon pools in a northern hardwood forest ecosystem. Soil Sci. Soc. Am. J. 52 (4): 1162-1167.

ACCESS
Public

DATA LOCATION
USDA Forest Service, Durham, NH

LAST UPDATED
1983

CONTACT PERSON
      John Campbell
      PO Box 640
      Durham, NH 03824
      Telephone: (603) 868-7643
      E-mail: jcampbell@lternet.edu

VARIABLES

Column Variable Description Units Coded Missing Value

1 obs Sample number - n none

2 pit H.B. grid location of pit - n none

3 depth depth - y none

4 %N percent nitrogen in oven dry soil (105 deg. C) % n none

5 %N percent carbon in oven dry soil (105 deg. C) % n none

6 MgN/ha megagrams of soil N per hectare Mg n none

7 CgN/ha megagrams of soil C per hectare Mg n none

CODES

Variable Code Description

depth 1 Oie horizon

depth 2 Oa horizon

depth 3 0-10cm depth mineral soil

depth 4 10-20cm depth mineral soil

depth 5 20cm depth in mineral soil to bottom of B horizon

DATA FILE NAME(S)
w583cn.txt

Column	Variable	Description	Units	Coded	Missing Value
1	obs	Sample number	-	n	none
2	pit	H.B. grid location of pit	-	n	none
3	depth	depth	-	y	none
4	%N	percent nitrogen in oven dry soil (105 deg. C)	%	n	none
5	%N	percent carbon in oven dry soil (105 deg. C)	%	n	none
6	MgN/ha	megagrams of soil N per hectare	Mg	n	none
7	CgN/ha	megagrams of soil C per hectare	Mg	n	none

Variable	Code	Description
depth	1	Oie horizon
depth	2	Oa horizon
depth	3	0-10cm depth mineral soil
depth	4	10-20cm depth mineral soil
depth	5	20cm depth in mineral soil to bottom of B horizon