Authors: Xavier Úbeda, Meritxell Alcañiz, Gonzalo Borges, Luis Outeiro and Marcos Francos
Abstract: The abandonment of the economic activities of agriculture, livestock, and forestry since the second half of the 20th century, in conjunction with the exodus of inhabitants from rural areas, has resulted in an increase in the forest mass as well as an expansion of forest areas. This, in turn, has led to a greater risk of forest ﬁres and an increase in the intensity and severity of these ﬁres. Moreover, these forest masses represent a ﬁre hazard to adjacent urban areas, which is a problem illustrated here by the village of Capafonts, whose former agricultural terraces have been invaded by shrubs, and which in the event of ﬁre runs the risk of aiding the propagation of the ﬂames from the forest to the village’s homes. One of the tools available to reduce the amount of fuel in zones adjoining inhabited areas is prescribed burns. The local authorities have also promoted measures to convert these terraces into pasture; in this way, the grazing of livestock (in this particular instance, goats) aims to keep fuel levels low and thus reduce the risk of ﬁre. The use of prescribed ﬁres is controversial, as they are believed to be highly aggressive for the soil, and little is known about their long-term eﬀects. The alternation of the two strategies is more acceptable—that is, the use of prescribed burning followed by the grazing of livestock. Yet, similarly little is known about the eﬀects of this management sequence on the soil. As such, this study seeks to examine the impact of the management of the abandoned terraces of Capafonts by means of two prescribed ﬁres (2000 and 2002), which were designed speciﬁcally to prevent forest ﬁres from reaching the village. Following these two prescribed burns, aherd of goats began to graze these terraces in 2005. Here,we report the results of soil analyses conducted during this period of years up to and including 2017. A plot comprising 30 sampling points was established on one of the terraces and used to monitor its main soil quality properties. The data were subject to statistical tests to determine whether the recorded changes were signiﬁcant. The results show modiﬁcations to the concentration of soil elements, and since the ﬁrst prescribed burn, these changes have all been statistically signiﬁcant. We compare our results with those reported in other studies that evaluate optimum soil concentrations for the adequate growth of grazing to feed goats, and conclude that the soil conditions on the terrace after 17 years are optimum for livestock use.