Effects of Burning on Carbon Utilization of Soil Microorganisms and Plant Growth of Carex brevicuspis Communities at Lake Poyang Wetlands, China

Abstract

Fire causes disturbance of wetland ecosystems and has a major influence on soil microbial communities, plant growth and ecosystem function. However, the impact of fire disturbance on soil microbial metabolism and its relationship with plant growth remains poorly understood. Burned zones, unburned zones and transition zones with low intensity fire were surveyed in an area dominated by Carex brevicuspis communities. Results show a significant difference in soil properties, microbial biomasses, microbial carbon utilization pattern and plant growth in different zones. The lowest average value of soil carbon content, nitrogen content and moisture occurred in burned zones, while the highest occurred in unburned zones. Furthermore, soil microbes under burned zones had the highest biomasses, average well color development value and richness index. Plant growth decreased in the following order: burned > transition > unburned zones. Redundancy analysis indicated that this variation can be explained mostly by the difference of carbon utilization patterns of soil microbes. Correlation and regression analyses show that soil microbial metabolism had a significant correlation with the plant growth variables tested in this study. Overall, our results suggest that fire changes the soil microenvironment and further changes the soil microbial metabolic patterns and plant growth in the Lake Poyang wetland.