Sampling design and laboratory analysis
This study was conducted in 1986 as part of the Jornada Basin LTER
program. The objective of this study was to measure plant tissue
nutrients at mesquite (Prosopis glandulosa) dune sites of
different habitat types. Mesquite tissues (leaf, stem, flowers,
pods) were collected in conjunction with phenology studies and
natural abundance of N15 during 1986 and 1987. This data package
has only 1986 data; 1987 data are in EDI package
knb-lter-jrn.210386009.
Four habitat types were sampled: (1) playa, within a dense stand
of large (3-5 m tall) mesquite growing along the edge of of a
large playa; (2) arroyo, with widely spaced mesquite trees (3-5 m
tall) along the margin of temporary water courses; (3) dunes,
which are dominated by low-growing coppice mesquite, and (4)
grassland, at the base of a watershed with widely scattered
mesquite, 2-3 m tall, many of the plants being multiple-stemmed.
The dune site is located on theJornada Experimental Range (JER),
while the other three sites are located on the NMSU Chihuahuah
Desert Rangeland Research Center (CDRRC).
Mesquite tissue samples were digested and analyzed for total
nitrogen (Kjeldahl) and total phosphorous. Plant tissue was
oven-dried at 60 degrees C and ground to 20 mesh in a Wiley mill.
One-tenth gram samples were weighed into 75ml Kjeldahl tubes and
digested on a block digestor (40 tubes at a time). The digest was
a micro- Kjeldahl sulfuric acid digest (Hg catalyst). An
autoanalyzer was used to determine NH4 (TKN-Total Kjeldahl
Nitrogen) and PO4-P (TP-Total Phosphorus). The method is described
in Bremner et al. 1982.
Additional files
An additional metadata file - prosnp86.dsd.txt - from the earlier
Jornada information management system is included and may contain
still useful metadata.
REFERENCES
Bremner, J.M., and C.S. Mulvaney. 1982. Nitrogen–Total. In A.L.
Page, R.H. Miller, and D. R. Keeney (eds.). Methods of soil
analysis. Part 2 - Chemical and microbiological properties.
Agronomy 9 (2):595-624. Am. Soc. of Agron., Madison, Wis.