SP033
Soil respiration associated with ectomycorrhizal mats in an old-growth stand along lower Lookout Creek, HJ Andrews Experimental Forest (2008-2009)

CREATOR(S): Barbara J Bond, Claire Phillips

PRINCIPAL INVESTIGATOR(S): Barbara J Bond

ORIGINATOR(S): Claire Phillips

DATA SET CONTACT PERSON: Claire Phillips

METADATA CONTACT: Claire Phillips, Fox Sparky Peterson

ABSTRACTOR: Fox Sparky Peterson

METADATA CREATION DATE:

13 Dec 2012

MOST RECENT METADATA REVIEW DATE:

4 Dec 2013

KEYWORDS:

populations, carbon cycling, soil, fungi, microbes

PURPOSE:

The purpose of this study was to determine if there was an the incremental increase in soil respiration associated with the formation, function, and persistence of rhizomorphic ectomycorrhizal mats, and to determine which environmental factors (temperature, moisture, etc.) had direct influences on soil respiration. Knowing the patterns and drivers of soil respiration from heterotrophs is key to understanding forest function and the connectivity between soil and vegetative organisms.

METHODS:

Experimental Design - SP033:

Description: Repeated measurements of respiration rate, soil moisture, and temperature were taken every 2-4 weeks at 12 pairs of mat and neighboring non-mat soils from July 2008 to December 2009 while the ground was free of snow.

Field Methods - SP033: Soil respiration and temp :

Description: Entity 1 (soil respiration and temperature): Twelve locations for respiration measurements were choosen randomly from approximately 20 suitable locations identified in an initial survey of mat coverage. Rhizomorphic mats were the most abundant type of EcM mat identified in the initial survey (hydrophobic mats were uncommon) and only rhizomorphic mats were selected for permanent measurements. Soil temperature was measured concurrently with respiration, using a Licor 6400 portable photosynthesis instrument with a LI-6400-19 soil chamber and a 10cm soil thermocouple probe. Respiration measurements were made with soil collars, which were inserted into the soil 1-2cm and left in place throughout the study. A few measurement locations were moved to accommodate recession or colonization of mats over time, and are noted in the data.

Field Methods - SP033: Gravimetric soil moisture :

Description: Entity 2&3 (gravimetric soil moisture): Soil moisture was measured gravimetrically in the Oi+Oe horizons, and at 5 and 15cm below the mineral soil surface, from cores taken at 6 small coring fields established across the site. Bulk density measured once at the beginning of the study was used to convert gravimetric measurements to volumetric water content at 5 and 15cm depth. A lookup table indicates the nearest respiration plots to each coring field.

Field Methods - SP033: Soil cores :

Description: Entity 4 (soil core data): At the outset of the study in July 2007, 10 Piloderma mat and 5 non mat soils (not paired) were choosed for one time respiration measurements (THESE ARE DIFFERENT LOCATIONS FROM LONGTERM RESPIRATION MEASUREMENTS). Soil cores were sampled destructively to measure root biomass, %C and %N, soil pH, moisture, and litter depth. Respiration rates were also measured prior to coring. Soils cores 8cm in diameter were removed in 4 depth increments: the entire O-horizon, 0-10cm, 10-20cm, and 20-35cm below the mineral soil surface. Fine root (less than 2mm diameter) and total root biomass were determined by wet sieving soils through 1mm sieves, and picking roots by hand. Soil pH was measured in wet soil slurries with distilled water. We measured total soil C and N by drying 1g of organic soil and 5g of mineral soil at 65°C for 48 hours, grinding soils to fine powder on a roller mill, and analyzing 3-10mg subsamples on a Costech ECS-4010 elemental combustion analyzer (Costech Analytical, Valencia, CA, USA) against an atropine standard.

Laboratory Methods - SP033:

Description: Entity 5: We assessed the presence of Piloderma by comparing T-RFLP patterns from soil extracts to those of known Piloderma isolates. Detailed methods of extraction and analysis are described by Blanchard (2008, M.S. Thesis, Oregon State University). Soil samples were kept cold on ice in the field and frozen at -80ºC upon returning to the lab. Three grams of frozen soil were ground with mortar and pestle to homogenize, and 0.25g of ground soil was used to extract DNA with the MOBio PowerSoilTM DNA isolation kit (MoBio Laboratories, Carlsbad, CA). We amplified fungal DNA using ITS1-F and ITS4 rDNA primers, with the forward primers fluorescently labeled with 5’-6-FAM (6-carboxyfluorescein). PCR products were cleaned to remove excess primer and nucleotides, and then digested with Hinf1 restriction endonucleases. The restriction products were submitted to OSU Center for Genome Research and Biocomputing for analysis. Size and relative abundance of the T-RFLP fragments were quantified using Genotyper® version 3.7 software (Applied Biosystems, Inc., Foster City, CA).

SITE DESCRIPTION:

Site was a 0.1ha area along lower Lookout Creek, approximately 700m downstream from Lookout Camp. Area was also used in the microbial observatory study (MO site 17). The forest stand was ~450 years old, dominated by Douglas-fir (Psuedotsuga menziesii) and western hemlock (Tsuga heterophylla), both hosts for mat-forming EcM species, and western redcedar (Thuja plicata), a host for arbuscular mycorrhizal fungi, which do not form mats. The understory plants included Acer circinatum, Gaultheria shallon, Vaccinium parvifolium, Polystichum munitum, Oxalis oregano, and the forest floor was covered with a layer of bryophytes. Fallen logs in advance stages of decay were common. The soil has strong andic properties and is classified as coarse loamy mixed mesic Typic Hapludands (Dixon, 2003), with an O-horizon depth of 4-9cm.

TAXONOMIC SYSTEM:

None

GEOGRAPHIC EXTENT:

A 0.1ha plot at HJ Andrews, along lower Lookout Creek, approximately 700m downstream from Lookout Camp, 44 deg 13”25’N, 122 deg 15”30’W, 484m above sea level

MEASUREMENT FREQUENCY:

Every 2-4 weeks spring-fall

PROGRESS DESCRIPTION:

Complete

UPDATE FREQUENCY DESCRIPTION:

notPlanned

CURRENTNESS REFERENCE:

Ground condition