Short-term responses of soil nitrogen mineralization, nitrification and denitrification to prescribed burning in a suburban forest ecosystem of subtropical Australia

Manyun Zhang; Weijin Wang; Dianjie Wang; Marijke Heenan; Zhihong Xu

doi:10.1016/j.scitotenv.2018.06.144

Short-term responses of soil nitrogen mineralization, nitrification and denitrification to prescribed burning in a suburban forest ecosystem of subtropical Australia

Sci Total Environ. 2018 Nov 15:642:879-886. doi: 10.1016/j.scitotenv.2018.06.144. Epub 2018 Jun 17.

Authors

Manyun Zhang¹, Weijin Wang², Dianjie Wang¹, Marijke Heenan³, Zhihong Xu¹

Affiliations

¹ Environmental Futures Research Institute, School of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia.
² Environmental Futures Research Institute, School of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia; Department of Environment and Science, Dutton Park, Queensland 4102, Australia. Electronic address: weijin.wang@qld.gov.au.
³ Department of Environment and Science, Dutton Park, Queensland 4102, Australia.

PMID: 29925058
DOI: 10.1016/j.scitotenv.2018.06.144

Abstract

As an anthropogenic disturbance, prescribed burning may alter the biogeochemistries of nutrients, including nitrogen (N) cycling, in forest ecosystems. This study aimed to examine the changes in N mineralization, nitrification and denitrification rates following prescribed burning in a suburban forest located in subtropical Australia and assess the interactive relationships among soil properties, functional gene abundances and N transformation rates. After a prescribed burning event, soil pH value increased, but soil labile carbon and mineral N contents decreased. Net N mineralization rates, potential nitrification rates and ammonium-oxidizing archaea and bacteria (AOA and AOB) amoA gene abundances in the soils all increased after 3 months of the prescribed burning. However, the abundances of different functional genes related to denitrification changed differently after the prescribed burning. The net N mineralization rates could be best described by soil abiotic properties, rather than functional gene abundances. In contrast, potential denitrification rates were positively related to soil nirK gene abundances. Potential nitrification rates could be influenced by both soil chemical and microbial properties. The results revealed that the prescribed burning might increase N mineralization and nitrification rates in the forest soil.

Keywords: Forest soil; Functional gene abundances; N transformation; Prescribed burning.