Giadrossich, Filippo; Murgia, Ilenia; Scotti, Roberto (2022): Experiment of water runoff and soil erosion with and without forest canopy coverage under intense artificial rainfall [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.943451

In the year 2015, the management of the Marganai forest (D.R.E.Am. Italia & R.D.M. Progetti, 2014) has been accused of promoting soil erosion through coppicing (Branca et. al, 2020; doi:10.3390/f11060708). In 2018 Regione Sardegna financed this project (within Progetto Sulcis, 2018) in the attempt to face the problem by adopting a scientific approach. Experimental trials have been conducted to evaluate the effect of forest coverage on sediment transport due to rain. The test plots pairs (or blocks) have been localized In two neighboring hillslopes (forest management parcels 20 and 41, 4 blocks per part) with similar conditions regarding soil characteristics, tree species, stumps density, and size. Each block included the contrasting situations: a plot with canopy cover (i.e. with a stump and its sprouts in the center of the plot) and one without a forest canopy cover. Individual plots are 1 m wide and 1.5 m long along the maximum slope gradient. On the downslope end water is collected, while other sides are delimited by planks. At the edge of plots, 3 rainfall gauges were positioned to check the rainfall distribution during each test. So the actual simulated rainfall intensity was calculated by weighted average according to Thiessen polygons. Artificial rain was provided, for two or three 30 min periods, with a mean intensity of 43 mm*h^-1, greatly exceeding rainfall records. The equipment was built by making a wooden tripod with a modular structure carrying the nozzle, similar to that used in Commandeur (1992), positioned 4 m above the ground, central with respect to the plot surface, in order to provide a homogeneous distribution of rainfall. The nozzle used is a calibrated Lechler nozzle (mod. 490.888) with a jet width of 120 degrees, to which an average water pressure of 1.5 bar was applied. Runoff and sediments were collected at the rate of 5 minutes in bottles of 0.5 liters. A total of 222 samples containing water and sediments were collected. All samples were weighted in the field and stored for laboratory analysis, where the separate weight of soil (solid particles) and organic matter has been determined. Due to the scarcity of sediments in each bottle, analysis has been carried out using 30 minutes aggregated samples.

Project

* Sostenibilità Ambientale e socioeconomica delle utilizzazioni forestali nei cedui del Marganai (SAM); Coordinator: Filippo Giadrossich; Institute: Universiy of Sassari, Department of Agricultural Sciences; Comment: Regione Autonoma della Sardegna; URL: https://nuoroforestryschool.io/Marganai

* Funder: Regione Autonoma della Sardegna; Award number: SULCIS-820965