TD029
Comparision of native litter species occurring at the Andrews Experimental Forest to LIDET standard species, 1993-2003

CREATOR(S): Mark E. Harmon

PRINCIPAL INVESTIGATOR(S): Mark E. Harmon

ORIGINATOR(S): Mark E. Harmon

DATA SET CONTACT PERSON: Mark E. Harmon

METADATA CONTACT: Becky Fasth

ABSTRACTOR: Mark E. Harmon

METADATA CREATION DATE:

20 Jun 2005

MOST RECENT METADATA REVIEW DATE:

12 Feb 2021

KEYWORDS:

Organic matter, decay rates, litterbags, decomposition, litterfall, nitrogen, phosphorus, organic matter, leaf litter

PURPOSE:

The primary objective of this study is to examine the control that substrate quality and climate have on patterns of long-term decomposition and nitrogen accumulation in above- and below-ground fine litter. Of particular interest will be to examine the degree these two factors control the formation of stable organic matter and nitrogen after extensive decay.

METHODS:

Experimental Design - TD029 :

Description: The major factors to be considered in this experiment will be six species of litter and incubation time. Samples will be collected four times at years 1, 2, 4, and 6. There will be four replicates for each species and time.

Field Methods - TD029:

Description:

Litter was collected from H.J. Andrews.

Bag Design

All bags were 20- by 20-cm and filled with 10 g leaves. Each bag was identified with a unique number embossed on an aluminum tag. The bag openings were sealed with six monel staples. The initial air dry weight, calculated oven dry weight, species, site, replicate number for each litterbag were recorded prior to placement in the field. Subsamples of litter material were taken to determine the air dry to oven dry conversion factor and the initial chemistry of the litter. Moisture content of the air dried litter ranged from 2-10% moisture content.

One type of bag was used in this experiment. The bags had a top mesh of 1 mm and a bottom of 55 micron mesh.

Sample Placement

Samples were placed in the field during fall of 1993. Locations were in areas protected from disturbances that could destroy the litter bags. The locations were also selected to be typical of areas that other decomposition experiments might be conducted.

• Four separate locations were selected to avoid pseudo- replication problems.
• Each set of bags to be collected was connected by a cord; these sets of bags should be laid out in parallel lines in a random order.
• Leaf litterbags should be placed so that contact with the underlying litter layer is made.

Sample Processing

Once the litter is collected it should be oven dried in a paper bags at 55°C until the mass is stable. Any mosses, lichens, fine roots, or other plant parts that have grown into the bags or dowels should also be removed prior to harvesting. Samples will be pooled by species, site, and time for grinding and archiving. A subset of unpooled samples will also be saved to determine the internal variability of pooled samples.

Laboratory Methods - TD029:

Description:

Chemical analyses will be performed using two methods. Each pooled sample from each species, site, and time will be analyzed for total nitrogen, lignin, and cellulose using near infrared reflectance spectoscopy (Wessman et al. 1988). Internal variability of samples will be estimated by running replicates of high and low lignin species. Twenty five percent of the pooled samples will also be sampled for Kjeldahl nitrogen, lignin, cellulose, water extractive, non- polar extractive, and ash content using wet chemical methods. Wet chemical methods will then be used to calibrate the near infrared reflectance spectoscopy methods.

Wessman, C. A., J. D. Aber, D. L. Peterson, and J. M. Melillo. 1988. Foliar analysis using near infrared reflectance spectroscopy. Can. J. For. Res. 18:6-11

SITE DESCRIPTION:

Mean annual temperature: 10 deg C

Mean annual precipitation: 2500 mm

Thronthaite AET: 552 mm

TAXONOMIC SYSTEM:

Garrison et al., 1976

GEOGRAPHIC EXTENT:

H.J. Andrews Experimental Forest, Oregon

MEASUREMENT FREQUENCY:

PROGRESS DESCRIPTION:

Complete

UPDATE FREQUENCY DESCRIPTION:

notPlanned

CURRENTNESS REFERENCE:

Ground condition