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Methods for Experiment 237 -

Effects of white pine invasion of old fields on biogeochemical processes

We are testing the hypothesis that white pine reduces soil pH and base cation availability, while accelerating rates of net N mineralization and decomposition. We are testing this hypothesis by sampling soil pH; total and exchangeable base cations; total soil C, N and P; potential net N mineralization; and leaf litter decomposition under white pines and in adjacent grassy openings in 5 old fields where white pine is currently invading.

aece237 - Soil Carbon and Nitrogen analysis

Soil Carbon and Nitrogen analysis

Soils were collected at depths of 0-20cm, 20-40cm, and 40-60cm, sieved through a 2mm sieve, dried, pulverized, and weighed for Carbon and Nitrogen analysis.

Soil Carbon and Nitrogen analysis - Instrumentation

Costech ECS4010 element analyzer (Costech Analytical, Valencia, California, USA) at the Ecosystems Analysis Laboratory - University of Nebraska, Lincoln.

aede237 - Litter decomposition

Litter decomposition

In September 2008 grass and pine needle litter was collected at Cedar Creek from the area where this experiment was conducted. On September 14, 2007. litter bags containing sorted grass or pine needles were placed under white pines and in adjacent grassy openings in 5 old fields where white pine is currently invading. Bag where collected over the next 4 years. Remaining litter was weighed and analyzed for carbon and nitrogen.

Litter decomposition - Instrumentation

Costech ECS4010 element analyzer (Costech Analytical, Valencia, California, USA) at the Ecosystems Analysis Laboratory - University of Nebraska, Lincoln.

aeee237 - Soil cation analysis

Soil cation analysis

Soils were collected at depths of 0-20cm, sieved through a 2mm sieve and extracted with 60 mL of BaCl2. Sample analysis by Inductively Coupled Argon Plasma Optical Emission Spectrometer (ICP) was conducted at UMN-Research Analytical Lab. see: http://ral.cfans.umn.edu/icp-analysis/

Soil cation analysis - Instrumentation

Perkin Elmer Optima 3000 ICP Spectrometer The Perkin Elmer Optima 3000 ICP Spectrometer is used for the majority of our routine analyses. We use it to analyze up to 27 different elements simultaneously using CCD detectors. It has a nitrogen purge spectrometer box. It is computer controlled for unattended operation with quality contol verification after every 10 sample unknowns. UMN-Research Analytical Lab: http://ral.cfans.umn.edu/major-equipmentequipment-used/