Soil microbial biomass activity and community com

Authors: Joanne Burton Chengrong Chen Zhihong Xu Hossein Ghadiri

Publish Date: 2010/04/30

Volume: 10, Issue: 7, Pages: 1267-1277

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Abstract

Soil nitrogen N availability is a critical determinant of plantation productivity in subtropical Australia and is influenced by the soil microbial community The size structure and function of the soil microbial community can be impacted by landuse change and residue management The objectives of this study were to examine the impact of landuse change from 1 native forest NF to first rotation 1R hoop pine plantation and 2 1R hoop pine plantation to second rotation 2R hoop pine plantation on the soil microbial community The impact of residue management on the soil microbial community was also investigated in the 2R forest where soil microbial parameters were measured in tree rows 2RT and windrows 2RW In addition relationships between soil microbial parameters and soil N parameters were investigatedEach of the four treatments NF 1R 2RT and 2RW had five 24m2 replicate plots from which 15 soil cores were collected and bulked at three depths 0–10 10–20 20–30 cm Microbial biomass carbon MBC and N MBN and soil respiration were measured on field moist soils In addition carbon C source utilisation patterns were assessed using the whole soil MicroResp™ technique Campbell et al 2003Results indicate that the landuse change from NF to 1R hoop pine plantation significantly reduced MBC respiration rate soil total C and total N Furthermore the landuse change appeared to have a significant impact on the soil microbial community composition measured using MicroResp™ profiles Landuse change from 1R to 2R hoop pine plantation resulted in a decline in total C and MBN and a shift in microbial community composition When compared to the 2RT soils the 2RW soils tended to have a greater microbial biomass and respiration rate Residue management also influenced the microbial community composition measured in the MicroResp™ profilesResults indicate that landuse change had a significant impact on the soil microbial community which was likely to be related to shifts in the quality and quantity of organic inputs associated with the change in land use This may have significant implications for the longterm productivity of the soil resource Further studies are required to confirm a difference in microbial community composition associated with residue management In addition longterm experiments in subtropical Australia are necessary to verify the results of this snapshot study and to improve our understanding of the impact of singlespecies plantation forestry and residue management on the soil microbial community soil N dynamics and ultimately the longterm sustainability of the soil resourceWe acknowledge the Forestry Plantations Queensland and in particular Mr Richard Jackson for allowing us access to the experimental site We would like to thank Dr Rui Yin Mr Yu Huang Mr Stephen Faggotter and Ms Elizabeth Bridon for their assistance in soil sampling and processing We also thank Mr James McBroom for statistical advice Finally we would like to acknowledge the financial support provided by the CRC for Sustainable Production Forestry Australian Rivers Institute and the Australian Research Council

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