06/09/81 to 12/11/90
PURPOSE:
To 1) measure the seasonality and mass of litterfall in the two soil series (Tully and Florence) and a hill-slope site on the LTER watersheds and 2) estimate the amount of nitrogen and phosphorus transferred to the soil by this means.
LOCATION OF SAMPLING STATIONS:
Adjacent to aboveground biomass sampling sites on the following watersheds:
Ungrazed, unburned Florence:020B (grid N-28)
Ungrazed, unburned Tully:020B (N-29)
Ungrazed, unburned hill-slope:020B (N-28)(Fig. 24)
Ungrazed, annually burned Florence - 2 sites:001D (R-27)
Ungrazed, annually burned Tully:001D (S-28)
Ungrazed, annually burned, hill-slope:001D (S-28)(Fig.26)
Ungrazed, annually burned Tully:001C (N-31)(Fig. 24)
Grazed, annually burned Tully:N01B (N/0-23)(Fig.26)
Grazed, 4 yr. burn, Tully:N04D (K/L-23)(Fig.27)
Ungrazed, 4 yr. burn Florence:004B (H-27/28)
Ungrazed, 4 yr. burn Tully:004B (F-29)
Ungrazed, 4 yr. burn hill-slope:004B (F-29)(Fig.28)
FREQUENCY OF SAMPLING
Monthly beginning on June 9, 1981 and ending December 11, 1990.
VARIABLES MEASURED:
Total dry weight of material obtained in litterfall collectors per collecting period and total-N and total-P per gram dry weight.
METHODS:
At each site, six or eight collectors were systematically arranged about 2 m apart along a 15 m transect marked by a steel conduit stake painted red and yellow. The collector was a split 2" PVC pipe (100 cm x 5.6 cm) with screened ends to allow for drainage. Special care was used to empty these troughs. Suspended litter above the traps can function as "rakes" and remove materials from troughs. Conversely the screen ends of the troughs can also act as rakes and remove suspended litter as the traps are pulled and cleaned. The best procedure in cleaning these traps was to pull them straight out (as opposed to at an angle above the soil), and use one hand to shield the top of the troughs from suspended litter. Traps were replaced by inserting the tubes upside-down, and turning the troughs over only when they were in place.
Further details concerning field collection are located in Bushnell Rm 218 in the "Copy of Field Notes" file.
Collected material was dried to constant weight at 70xC. nitrogen and phosphorus content were determined by digestion in H2SO4 followed by calorimetric measurements using a Technicon Autoanalyzer. Further details are provided in Appendix A.
HISTORY OF THE DATA SET:
Prior to 1983, this data set was designated as (PPL01). In 1982, samples were collected from Tully and Florence soil sites on three watersheds only (020B, 001D, and 004B). In 1982, three additional sites (Tully soil only) were added (N04C, N01D, and 001C). Also, sampling on Florence sites on 001D was expanded to two sites with six collectors each (instead of one site with eight collectors). Interest in litterfall deposition on slopes caused a change in methods in 1987. Six collectors were placed at the established sampling stations and additional stations were located on hill-slopes in watersheds 020B, 004B, and 001D. The sites on N01B, N04D, and 001C each had eight collectors, as before 1987.
