Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Canada → Effects of Prescribed Fire on Soil Biogeochemistry in a Mixed Grass Prairie

University of Saskatchewan (2022)

Effects of Prescribed Fire on Soil Biogeochemistry in a Mixed Grass Prairie

Kroeger, Jackie

Titre : Effects of Prescribed Fire on Soil Biogeochemistry in a Mixed Grass Prairie

Auteur : Kroeger, Jackie

Université de soutenance : University of Saskatchewan

Grade : Master of Science (M.Sc.) 2022

Limited information exists regarding the effects of prescribed fire on soil biogeochemistry in the mixed grasslands of North America. This study investigated the effects of prescribed grassland fire on soil biogeochemistry over two growing seasons in the mixed grass prairies of Southern Saskatchewan. Spring burning was conducted in continuously grazed native and tame pastures. Soils were sampled (0-10 cm) 2, 3, 4 and 15, 16, 17 months after fire in burned and adjacent control plots. Investigation of soil biogeochemical changes include the analysis of soil total carbon (C), nitrogen (N), microbial biomass C (MBC), microbial biomass N (MBN), C stock, pH, electrical conductivity (EC) and characterization of the microbial community through phospholipid fatty acid biomarker extraction. Results indicate that the mixed grasslands in southern Saskatchewan are largely resistant and resilient to the effects of disturbance by fire. Slight changes in the microbial community structure were observed in both pastures ; burning increased the homogeneity in microbial community composition. Attributed to a post fire nutrient flush, the tame forage pasture had an increase in soil fungi 2-4 months following fire and an increase in the ratio of Gram-negative bacteria to Gram-positive bacteria throughout the duration of the study. Temporal effects on soil biogeochemistry were stronger than fire effects. Pastures responded differently over time, likely due to differences in vegetation composition and abundance as well as land use history. This research shows that the use of prescribed fire is compatible with soil conservation principles, as negative effects on soil biogeochemistry were not observed. Reducing barriers to the use of prescribed fire in grassland management is important for the preservation and productivity of remnant grassland parcels, and the ecosystem services grasslands provide.


Version intégrale (10 Mb )

Page publiée le 22 mars 2023