Fire Damage to the Soil Bacterial Structure and Function Depends on Burn Severity: Experimental Burnings at a Lysimetric Facility (MedForECOtron)

Abstract

The soil microbiota is vulnerable to burning; however, it shows some resilience. No indices have yet been developed to assess fire damage related to soil biota. We evaluated the biological soil indices recorded by a Biolog EcoPlate System in a Mediterranean ecosystem. The experiment was carried out in an outdoor forest lysimeter facility (MedForECOtron), where we simulated burns with different burn severities. Burning increased the metabolic diversity of bacteria and most C-substrate utilization groups. Soil organic matter, phosphorus, electric conductivity, and calcium increased with increasing burn severity. Microbial richness and activity, as well as the integrated capacity of soil microbes to use a C source, lowered by burning, but recovered 6 months later. The functional diversity and amount of the C source used by microbes immediately increased after fire, and values remained higher than for unburned soils. We evaluated the changes in the vulnerability and resilience of fire-adapted ecosystems to improve their adaptive forest management. We found that the high burn severity reduced microbial richness, functional diversity, and the C source utilization of soil microbes (marked vulnerability to high temperatures), which recovered in the short term (high resilience). These results help to understand the main mechanisms of the effects of wildfire on semi-arid Mediterranean ecosystems, whose field validation will be helpful for fire prevention planning and restoration of burned areas.

Wildfires’ Effect on Soil Properties and Bacterial Biodiversity of Postpyrogenic Histic Podzols (Middle Taiga, Komi Republic)

“…Forest fires' effects on the studied soil microorganisms are discussed below. Recent studies claim that fires can sterilize the soil [25,83,84]. The loss of these microorganisms not only affects biodiversity and interaction networks with plants or animals, but also their structures, such as filaments or biofilms, which are very relevant as adhesive agents aggregating particles and improving the soil structure [83][84][85].…”

Combined Use of a Bacterial Consortium and Early-Colonizing Plants as a Treatment for Soil Recovery after Fire: A Model Based on Los Guájares (Granada, Spain) Wildfire

“…Furthermore, it is important to point out that fires are going to dramatically change the microbiota associated with the soil [ 27 , 28 , 29 ]. The loss of these microorganisms not only affects biodiversity and the networks of interactions with plants or animals, but also their structures, such as filaments or biofilms, that are very relevant as adhesive agents aggregating particles and improving the soil structure, as some authors reported for this region [ 9 , 29 , 30 ]. Hence, among the most common bacterial genera and species referenced in soils subject to different fire intensity, we can find Pseudomonas spp.…”

“…(as Pseudomonas fluorescens ), Arthrobacter spp., Burkholderia spp., Cohnella spp., Massilia spp., Blastococcus spp., Microvirga spp., Stenotrophomonas spp., Bacillus spp., and Clostridium spp. All these species are present in Mediterranean soils, and may serve in soil aggregation, as most of them are able to produce biofilms [ 27 , 28 , 29 , 30 , 31 , 32 ]. These microbial structures and activities can help in moisture retention [ 28 , 31 , 33 ], as well as help in nutrient cycling, critically influencing the availability of the main nutrients (fixing N, solubilizing P, K, S oxidizing) and micronutrients (siderophores and chelators for Mg, Ca, or Fe) for soil organisms and plants [ 34 ].…”

Integrating Machine Learning and a Spatial Contextual Algorithm to Detect Wildfire from Himawari-8 Data in Southwest China

“…China is also a country that suffers from wildfire. Wildfire, which causes significant damage to the ecological environment and socio-economic development, threatens the safety of people's lives and property and destroys surface vegetation and topsoil [2][3][4][5]. Therefore, timely and accurate wildfire detection is necessary for protecting the ecological environment and stabilizing the social economy.…”