Application of an electronic micropenetrometer to assess mechanical stability of biological soil crusts

作者：Drahorad Sylvie Laureen^*; Felix Henningsen Peter

来源：Journal of Plant Nutrition and Soil Science, 2013, 176(6): 904-909.

DOI：10.1002/jpln.201200291

• penetration resistance
• BSC
• Negev desert
• sand dunes
• disturbance

An in situ determination of biological soil-crust stability was carried out in two study sites along a sharp rainfall gradient. Penetration resistance (PR) of the crusts was measured using a newly developed light-weight needle-type electronic micropenetrometer. The depth-related PR data revealed two sections possessing different structures and stability. The topcrust (0-2mm) had significantly higher amounts of N, organic C, carbonates, and salts as compared to the underlain subcrust. The mean PR of the topcrust was 0.68 MPa for the southern study site, Nizzana-South (approximate to 100mm annual rainfall), and it increased significantly for the northern study site, Nizzana-69 (approximate to 170mm annual rainfall), with a mean of 1.11 MPa. A subcrust (2-30mm) was identified that was characterized by a high amount of carbonates and a PR %26gt; 2 MPa. The electronic micropenetrometer system is a promising device for identifying areas of changing crust stability in relation to biological soil-crust properties. The overall stability of biological soil crusts depends on the topcrust and subcrust structure. This structure is linked to abiotic and biotic factors and likely in relation to the amount of annual precipitation.

• 出版日期2013-12