https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Comparing transient and steady-state analysis of single-ring infiltrometer data for an abandoned field affected by fire in Eastern Spain https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32351 fs, of an unmanaged field affected by fire by means of single-ring infiltrometer runs and the use of transient and steady-state data analysis procedures. Sampling and measurements were carried out in 2012 and 2017 in a fire-affected field (burnt site) and in a neighboring non-affected site (control site). The predictive potential of different data analysis procedures (i.e., transient and steady-state) to yield proper Kfs estimates was investigated. In particular, the transient WU1 method and the BB, WU2 and OPD methods were compared. The cumulative linearization (CL) method was used to apply the WU1 method. Values of Kfs ranging from 0.87 to 4.21 mm·h-1 were obtained, depending on the considered data analysis method. The WU1 method did not yield significantly different Kfs estimates between the sampled sites throughout the five-year period, due to the generally poor performance of the CL method, which spoiled the soil hydraulic characterization. In particular, good fits were only obtained in 23% of the cases. The BB, WU2 and the OPD methods, with a characterization based exclusively on a stabilized infiltration process, yielded an appreciably lower variability of the Kfs data as compared with the WU1 method. It was concluded that steady-state methods were more appropriate for detecting slight changes of Kfs in post-fire soil hydraulic characterizations. Our results showed a certain degree of soil degradation at the burnt site with an immediate reduction of the soil organic matter and a progressive increase of the soil bulk density during the five years following the fire. This general impoverishment resulted in a slight but significant decrease in the field-saturated soil hydraulic conductivity.]]> Mon 23 Sep 2019 13:14:44 AEST ]]> Pinus halepensis M. versus Quercus ilex subsp. Rotundifolia L. runoff and soil erosion at pedon scale under natural rainfall in Eastern Spain three decades after a forest fire https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34247 Pinus halepensis M.) is the species commonly used for afforestation in the Mediterranean and is very successful when natural recovery takes place, however, the original forests were composed of Holm oaks (Quercus ilex subsp. rotundifolia L.). There is little information about the hydrological and erosional impact of this change of vegetation cover stimulated by a millennia old forest use in the Mediterranean, and a century old afforestation policies and natural recovery as a consequence of land abandonment. To get insights in the effect of plant species on runoff generation and soil erosion, individual trees should be selected. Plots of 1 m² are necessary to identify homogeneous patches, and were installed under Aleppo pine (4 plots) and Holm oaks (4 plots) in a 30(34)-years old plant cover recovered after a forest fire that took place in 1979. A raingauge was installed in the study site to characterize the rainfall. The soil erosion plots were built with metal borders and each plot drained to a collector (gutter) and a 60 L container to store the surface runoff. Runoff was measured after each rainfall event and sediment concentration was determined by desiccation. Results show that Aleppo pine covered soils yield six times more runoff (232 mm, 8.31%) than Holm oaks (40 mm, 1.4%) during the experimental period of 2010-2014, when rainfall amount 2,721.1 mm. Runoff sediment concentration was higher in the Aleppo pine plots (4.9 g 1⁻¹) than in the Holm oaks plots (2.6 g 1⁻¹). Soil erosion rate was ten times higher in Aleppo pine (2.6 Mg ha⁻¹ y⁻¹) than in Holm oaks (0.26 Mg ha⁻¹ y⁻¹).]]> Fri 22 Feb 2019 16:55:50 AEDT ]]>