1. Trembling aspen (Populus tremuloides) and loblolly pine (Pinus Taeda) are the standard substrate used for wood stakes to contrast differing lignin and cellulose contents (softwood vs. hardwood) in sapwood.
   
   

   Installing stakes at study site [view medium photo - 56K] [view large photo - 105K]		Close-up of photo to left
   		Forest Service crew installing wood stakes for decomposition study on an LTSP study site [view medium photo - 84K] [view large photo - 204K]

   
   
2. Western hemlock (Tsuga heterophylla), a native species was used only in the fall insertion.
   
   
3. The stakes were extracted every six months for 2.5 years, the last stakes were extracted in October 2000.
   
   Stake extraction
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   Forest Service crew selecting and marking sample points
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   Forest Service crew selecting and marking sample points
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   Forest Service crew taking measurements and collecting decomposition samples from a treated plot
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   Forest Service crew taking measurements and collecting samples from an untreated (control) plot
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4. Stakes are cut into three blocks, representative of the three soil depths and are conditioned at 12% EMC.
   
   Blocks at representative soil depths
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5. Two measures of decomposition are used; compression parallel to grain test (ASTM 143 Sec 55-62) and weight loss.
   
   Compression parallel to grain test
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   Instrumentation for in-ground wave speed test of maximum compression strength on wood stake (Oscilloscope and impacter)
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   Instrumentation for in-ground wave speed test of maximum compression strength (Close-up of impacter)
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   Instrumentation for out-of-ground wave speed test of maximum compression strength (Wavemeter and impacter/sensors)
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6. Soil measurements taken: CO₂, hydrosense readings
   
   Taking soil CO₂ readings
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   Forest Service crew taking soil strength measurements
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   Testing soil strength
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   Applying foam method for bulk density sampling
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See References >