Soil Biological, Chemical, and Physical Properties After a Wildfire Event in a Eucalyptus Forest in the Pampa Biome

Abstract

Wildfire events cause considerable environmental disturbance but few studies have examined changes in soil properties due to fire. This study aimed to assess the effect of a wildfire event on chemical, physical, and biological properties of the soil in a eucalyptus forest in the Pampa biome. Part of a seven-year-old eucalyptus forest was affected by a wildfire event that lasted for two days. Soil and plant litter sampling was performed in three areas: in the forest that was not affected by the fire, in the forest affected by it, and in an adjacent natural pasture area (the original vegetation). Seven samples were collected from the 0.00-0.05 and 0.05-0.20 m layers of each plot for biological analysis, and three samples were collected for chemical and physical analyses. Disturbed soil samples were collected in order to determine pH, organic matter, acidity, and nutrient content. Undisturbed samples were collected to determine soil microporosity, macroporosity, total porosity, and density. Soil macrofauna was assessed through the Tropical Soil Biology and Fertility method, and biological activity was tested through substrate consumption in the bait-lamina test. The fire increased soil pH values, CEC, and base saturation, as well as K, Ca, and Mg content; it decreased potential acidity and P content in the soil. Soil physical properties were not altered by the wildfire. The total abundance of macrofauna and of annelids, arachnids, coleoptera, and isoptera decreased due to the wildfire, resulting in lower soil diversity. Hymenoptera abundance increased because of the fire event. The feeding activity of organisms in the soil surface layer decreased due to the fire. The wildfire in the eucalyptus forest in the Pampa biome altered soil chemical and biological properties.

Conservation agriculture-related practices contribute to maize (Zea mays L.) yield and soil improvement in Central Malawi

“…pH increases significantly only if burning occurs at high temperatures to achieve complete combustion of vegetative residues ( Arocena and Opio, 2003 ). The non-replenishment of organic materials would also be responsible for the low pH in the FP since less alkaline cations could be released during burning ( Santana et al., 2018 ). There is a positive correlation between pH and SOM ( Chungu et al., 2019 ); therefore, with the decreasing SOM in FP, pH would not be expected to increase even after occasional burning.…”

Fire alters the availability of soil nutrients and accelerates growth of Eucalyptus grandis in Zambia

“…and Mg 2? (Certini 2005;Santana et al 2018). A significant increase in pH as a result of burning occurs only at high temperatures as a result of the complete combustion of vegetative residues and is well correlated with concentrations of Ca 2?…”

Passage of Wheat Fire Impact on Soil Properties and Environment in Kurdistan Region

“…The slashand-burn system for cropping maize and black beans in Southern Brazil was shown no effect on soil organic matter, however, the stability of soil aggregates increased when compared to unburned soil (39). Post-fire was increased the main soil nutrients, such as Ca, Mg, K and CEC (38), but soil pH, Al and Mn were decreased after a month of the fire, and no changes were found in the level of Na, Fe and Zn, therefore, it was suggested that the low fire severity have no negative impact on soil properties (32,34). Soil pH and fire severity are the key drives of fungal composition, total fungal, mycorrhizal, and saprotroph were higher in boreal forests of western Canada after an event of low fire severity and low pH (12).…”

“…Soil pH and fire severity are the key drives of fungal composition, total fungal, mycorrhizal, and saprotroph were higher in boreal forests of western Canada after an event of low fire severity and low pH (12). Low activity of some soil organisms was found due to the wildfires, which was suggested that wildfire modify soil chemical and biological properties (14,38). The action of heat modifies the soil chemical and physical status (45) and thus alterations in microbial populations may be expected following soil burning.…”

“…Most research on fire effects on microorganisms has been devoted to controlled fires (13). In addition to the positive effect of wildfire on some key soil nutrients (33,34,38), it was found that wildfire stimulated seed germination by breaking the dormancy of some angiosperm and gymnosperm seeds (8,21). Despite of the huge number of studies investigated the impact of wildfire on soil properties and seed bank as mentioned above, there are few researchers studied the impact of prescribed fire on soil fertility and yield in wheat farm.…”