Comparison of two methods that assess soil community level physiological profiles in a forest ecosystem

TitleComparison of two methods that assess soil community level physiological profiles in a forest ecosystem
Publication TypeJournal Article
Year of Publication2007
AuthorsLalor B.M, Cookson W.R, Murphy D.V
JournalSoil Biology & BiochemistrySoil Biology & Biochemistry
Volume39
Pagination454-462
Date PublishedFeb
ISBN Number0038-0717
Accession NumberWOS:000243209100008
Keywordsbiomass, carbon-source utilization, catabolic diversity, clpp, degens and harris, fuel loads, functional diversity, microbial communities, microbial heterotrophic function, microresp (tm), mine site rehabilitation, organic-c, rehabilitated bauxite mines, utilization patterns, western-australia
Abstract

There are currently two approaches that use whole soil to determine community level physiological profiles (CLPP) based on G substrate utilization. We assessed the Degens and Harris and MicroResp (TM) approaches for their ability to distinguish between previously mined and non-mined forest soils that are characterized by gradients in biological, chemical and physical properties. Surface soils (0-5 cm) were collected from two ages of forest rehabilitation (3- and 16-years post mining), within mounds and furrows (caused by contour ripping) and from adjacent non-mined forest soil. Microbial respiration response to individual substrates was six times greater from the Degens and Harris (1.84 mu g CO2-C g soil h(-1)) than the MicroResp TM (0.31 mu g Co-2-C g soil h(-1)) approach. The MicroResp (TM) approach was able to distinguish between CLPP of the two ages of rehabilitation (P = 0.05), whereas the Degens and Harris approach did not. Neither approach identified an overall difference between the CLPP of mined and adjacent non-mined forest. The MicroResp TM approach revealed a significant difference (P = 0.03) in CLPP from mounds of the two rehabilitation ages but no differences between the furrows. In addition there was a difference (P = 0.03) in CLPP between the mounds and furrows within the 3-year old rehabilitation but no difference between the mounds and furrows within the 16-year-old rehabilitation. However, the CLPP of mounds of the 3-year old rehabilitation were different (P = 0.059) to adjacent non-mined forest, while the furrows were not. There was no difference in CLPP between the mounds or the furrows of the 16-year-old rehabilitation and adjacent non-mined forest. These results suggest that the aspect of microbial heterotrophic function measured in this study takes up to 3 years to re-establish in the furrows and between 3-16 years in the mounds of post-mined rehabilitation soils. Our results also indicated that the MicroResp TM was substantially better than the Degens and Harris approach in distinguishing between treatments; this is likely to be due to differences in substrate concentrations and soil water potentials between approaches. Testing of a more comprehensive range of organic compounds would likely provide greater ecological interpretation of the CLPP data. (c) 2006 Elsevier Ltd. All rights reserved.

Short TitleSoil Biol. Biochem.
Alternate JournalSoil Biol Biochem