| Autor: |
Pennypacker, S. P., Sopper, W. E., Kardos, L. T. |
| Zdroj: |
Soil Science Society of America Journal; September 1975, Vol. 39 Issue: 5 p973-978, 6p |
| Abstrakt: |
The insulating value of red pine (Pinus resinosaAit.) forest floor litter was determined by measuring thermal conductivity, k, using a heat line source method. Test specimens consisted of natural forest floor and individual samples of reconstituted needle and humus components that had respective average dry weight bulk densities of 0.058, 0.229, and 0.233 g/cm3. Measurements were taken of the organic material under both frozen and unfrozen conditions at moisture contents ranging from oven‐dry to approximately 300% by weight. The conductivity of the three materials was expressed as a function of moisture content and density at temperatures of approximately — 16 and 25C. Freezing increased conductivities in reconstructed samples of organic particles, but not in natural samples. The failure to obtain increased conductivities in natural samples is probably due to the absence of an ice formation or a structure of adjoining ice crystals within the porous humus layer. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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