The effects of stumping and tree species composition on the soil microbial community in the interior cedar-hemlock zone, British Columbia
department or school: Land and Food Systems, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Modi, Dixi
issued: 2019-12-24T21:40:52Z
issued: 2019
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Stump removal (stumping) is an effective forest management practice used to reduce the mortality of trees affected by fungal pathogen-mediated root diseases such as Armillaria root rot, but its impact on soil microbial community structure has not been ascertained. This study investigated the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal and bacterial communities in a 48-year-old trial at Skimikin, British Columbia. We used DNA metabarcoding targeting the fungal internal transcribed spacer (ITS) marker and the bacterial 16S rRNA gene to decipher the microbiomes. A total of 108 samples were collected from the FH (fermented and humus layers), 0-10 cm (A horizon) and 10-20 cm (B horizon) layers in 36 plots, 18 stumped and 18 unstumped, that were planted with pure stands and admixtures of Douglas-fir, western redcedar and paper birch. Fungal α-diversity in the A horizon increased with stumping regardless of tree species composition and had a tendency to increase in the FH and B horizons. In the FH horizon, the relative abundance of the saprotrophic fungal community declined while that of ectomycorrhizal (ECM) fungal community increased with stumping. Bacterial α-diversity in the B horizon declined with stumping, irrespective of tree species, and also tended to decrease in the A horizon. The B horizon of stumped plots was significantly enriched with potential plant growth-promoting bacteria (PGPR), such as rhizobia. Similarly, Pseudomonadales, known for their antagonistic role against pathogens, increased significantly in all three soil horizons with stumping and was especially observed in association with birch and its admixtures. The culture-based assessment focused on 16S rDNA substantiated the dominance of potential PGPRs in the stumped plots. Furthermore, molecular characterization of Armillaria using translation elongation factor-1 alpha (tef-1) and ITS revealed the occurrence of A. gal…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/72987
note: The effects of stumping and tree species composition on the soil microbial community in the Interior Cedar Hemlock Zone, British Columbia by Dixi Modi B.Sc. in Biotechnology, Veer Narmad South Gujarat University, India, 2010 M.Sc. in Biotechnology, Veer Narmad South Gujarat University, India, 2012 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate and Postdoctoral Studies (Soil Science) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) December 2019 © Dixi Modi, 2019ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a dissertation entitled: “The effects of stump removal and tree species composition on soil microbial communities in the Interior Cedar Hemlock zone, British Columbia.” submitted by Dixi Modi in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Soil Science. Examining Committee: Prof. Suzanne W. Simard, Forest and Conservation Sciences Supervisor Prof. Les Lavkulich, Land and Food Systems Co-Supervisor Prof. Richard C. Hamelin, Forest and Conservation Sciences Supervisory Committee Member Prof. Sue J. Grayston, Forest and Conservation Sciences Supervisory Committee Member Prof. Chris Chanway University Examiner Prof. Patrick Keeling University Examiner Prof. Kathy Lewis External Examiner iii Abstract Stump removal (stumping) is an effective forest management practice used to reduce the mortality of trees affected by fungal pathogen-mediated root diseases such as Armillaria root rot, but its impact on soil microbial community structure has not been ascertained. This study investigated the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal and bacterial communities in a 48-year-old trial at Skimikin, British Columbia. We used DNA metabarcoding targeting the fungal internal transcribed space…
has type: Thesis/Dissertation
date issued: 2020-05
is shown at: 10.14288/1.0387334
language: eng
degree discipline: Soil Science
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/72987