Summary
The main form of land degradation is water erosion and solute- and sediment-related nutrient losses after fire. Apart from trying to prevent wildfire, the remediation techniques are intended to reduce erosive runoff and limit erosion. Both prevention and remediation solutions will be assessed in selected catchments, as follows:
Site 1 (Caratão catchment near Mação) is more focused on reforestation. The Mação Region suffered massive fires in 2003 and 2005, and now more than 70% of the municipality has been burnt. Natural degradation and regeneration, together with mitigation techniques are being assessed at this location.
Site 2 (Vale Torto catchment near Góis) is more focused on the use of prescribed fire as a wildfire prevention tool. The Vale Torto area is a shrubland area where prescribed fire was carried out on February 20th 2009 as an experimental fire (broadly equivalent to a prescribed fire near the catchment boundaries but hotter towards the main drainage line), and where the impacts will be assessed for at least 2 years after the fire. The area was burned by several fires in the 1970s and the early 1980s. In the early 1990s, the common land was burned using prescribed fire to provide grazing areas for the surrounding villages. It has not been burned since. An unburnt catchment of similar size is being monitored for discharge and bedload sediment trapped behind the gauging station v-notch weir.
Site 3 (Camelo catchment near Góis) is similar in many respects to Vale Torto catchment in that it has similar rainfall, geology, topography, soil and vegetation cover. It was subject to wildfire in July 2008, and so provides a useful comparison to Vale Torto in terms of assessing the degree to which prescribed fire causes less erosion than wildfire. Monitoring began before the first erosive rainfall events.
Site 4 (Moinhos, near Miranda do Corvo) is a catchment affected by wildfire in September 2009. It comprises both Pinus pinaster and Eucalyptus globulus plantations. Monitoring to assess the effectiveness of post-fire mitigation measures began in October 2009.
The main aim of the experimental set-up at Site 4 is to test remediation techniques following wildfire. After an initial period to establish the patterns of soil erosion at the different sites, the effect of the following treatments are expected to be assessed:
- leaving timber waste in different available quantities on the surface.
- allowing pine needlefall onto the soil from the scorched tree canopy.
Small-scale experiments will be done to test the effects of burning different types and quantities of litter on soil characteristics, conducted at the ESAC experimental station in Coimbra.
The field experiments are aimed at integrating various methodologies at different scales, within selected small catchments in order to provide the integration context.
