| Popis: |
This paper is the third in a series on the design and construction (Knaus 1986) and improvements (Knaus and Cahoon 1990) of a cryogenic soil-coring device (cryocorer). Freezing wetland soils in place during sampling eliminates compaction, dewatering, and loss of flocculent material at the water-sediment interface. The cryocorer is suitable for sampling soils of emergent marsh and mangrove forests as well as shallow water bottoms, although it has been used primarily for the former. A small-diameter frozen soil core minimizes disruption of the surface, can be evaluated immediately for overall quality, and can be used to measure soil profiles and subsample for further analysis. The cryocorer continues to be used in studies of wetland accretion and soil bulk density throughout the US. Concomitant with the increased use of the device, improvements in cryocorer design and application have occurred. Reported here are improvements in design that have been made since 1992 with references to wetland research in which the cryocorer has been used extensively. |
