Do Wildfires Cause Changes in Soil Quality in the Short Term?

Abstract

Wildfires have high frequency and intensity in the Mediterranean ecosystems that deeply modify the soil abiotic (i.e., pH, contents of water, organic matter and elements) and biotic properties (i.e., biomass and activity). In 2017, an intense wildfire occurred inside the Vesuvius National Park (Southern Italy), destroying approximately 50% of the existing plant cover. So, the research aimed to evaluate the fire effects on soil quality through single soil abiotic and biotic indicators and through an integrated index (SQI). To achieve the aim, soil samples were collected inside the Vesuvius National Park at 12 sampling field points before fire (BF) and after fire (AF). The findings highlighted that in AF soil, the contents of water and total carbon, element availability, respiration and the dehydrogenase activity were lower than in BF soil; in contrast, pH and hydrolase activity were significantly higher in AF soil. The microbial biomass and activity were affected by Al, Cr and Cu availability in both BF and AF soils. Despite the variations in each investigated soil abiotic and biotic property that occurred in AF soil, the overall soil quality did not significantly differ as compared to that calculated for the BF soil. The findings provide a contribution to the baseline definition of the properties and quality of burnt soil and highlight the short-term effects of fire on volcanic soil in the Mediterranean area.

Combined Effects of Wildfire and Vegetation Cover Type on Volcanic Soil (Functions and Properties) in a Mediterranean Region: Comparison of Two Soil Quality Indices

“…Although the soil characteristics and functions showed significant changes according to vegetation cover type and fire occurrence, both the additive (SQI) and weighted function (SQI FUNCT ) soil quality indices showed a medium soil quality and did not significantly vary according to the vegetation cover type. The results obtained by the SQI agree with Memoli et al [ 16 ] and could be due to the fact that the fire responses of the single characteristics sometimes were opposite, suggesting that they can be compensated when their interactions are considered. However, the integrated SQI is dependent on several factors such as the design of the study, choice of soil parameters included in the model to compute SQI and endpoint variables [ 46 ].…”

“…With this framework, the research objectives were to: (i) evaluate the impact of fire and vegetation and their interaction on single soil; (ii) use a simple additive method (SQI) and a weighted additive method (SQI FUNCT ) to evaluate the overall soil quality and functionality; (iii) highlight which among the studied vegetation cover types mitigated or enhanced the fire impact. Starting from a previous study [ 16 ], where no impacts of fire on soil quality index (SQI) were highlighted, the present research hypothesizes that soil quality indexes calculated by considering different functions (SQI FUNCT ) could be more informative than the SQI. Moreover, the SQI FUNCT could also highlight different fire impacts on the quality of soils under the studied vegetation cover types.…”

Impact of Anthropic Activities on Soil Quality under Different Land Uses

“…The Vesuvius National Park is by densely populated municipalities and it attracts numerous tourists each year [13]. The vegetation inside the National Park is characterized by Mediterranean vegetation, mainly dominated by trees such as holm oak, pines, maple and alder [28]. The selected sampling points are located inside the Riserva Alto Tirone Vesuvio, where the main vegetation cover is holm oak trees.…”

“…The sieved soil samples were analyzed for pH, water content and total C and N concentrations. Soil pH was measured in a soil: distilled water suspension (1:2.5 = w/w) by an electrometric method [33]; soil water content (WC) was determined gravimetrically by drying fresh soil at 105 • C until to reach constant weight [28]; C and N concentrations were determined by elemental analyzer (Thermo Finnigan, Mundelein, IL, USA, CNS Analyzer) on dried and pulverized samples (Fritsch Analysette Spartan 3 Pulverisette 0).…”

“…Because of the growing public interest in sustainability and the desire to determine effects of land use and management practices on soil resources, one of the most important goals for modern soil science is to understand and assess soil quality [26]. One way to integrate information from soil indicators into the management decision process is the use of a soil quality index, as a primary indicator of sustainable land management [27][28][29].…”