Root influence on soil nitrogen availability and microbial community dynamics results in contrasting rhizosphere priming effects in pine and spruce soil
(2021) In Functional Ecology 35(6). p.1312-1324- Abstract
The rhizosphere priming effect (RPE) is increasingly considered an important regulator of below-ground C and N cycling, with implications for terrestrial ecosystem feedback to global change. Even so, there is a lack of knowledge about the mechanisms underlying RPEs. We used novel stable isotope probing methods to investigate RPEs in an experiment with Scots pine and Norway spruce seedlings, two of the most common boreal forest species. We determined root exudation rates, RPEs on SOM decomposition and gross N mineralization, and the contribution of different microbial functional groups to the observed RPEs. Pine induced positive and spruce induced negative RPEs on SOM decomposition, while no RPE on gross N mineralization was observed.... (More)
The rhizosphere priming effect (RPE) is increasingly considered an important regulator of below-ground C and N cycling, with implications for terrestrial ecosystem feedback to global change. Even so, there is a lack of knowledge about the mechanisms underlying RPEs. We used novel stable isotope probing methods to investigate RPEs in an experiment with Scots pine and Norway spruce seedlings, two of the most common boreal forest species. We determined root exudation rates, RPEs on SOM decomposition and gross N mineralization, and the contribution of different microbial functional groups to the observed RPEs. Pine induced positive and spruce induced negative RPEs on SOM decomposition, while no RPE on gross N mineralization was observed. Negative RPEs in the spruce treatment were attributed to an opportunistic subset of the fungal community that was growing on root-derived 13C while depleting available N, thus reducing the activity of microbial SOM decomposers. In the pine treatment, available N was likely sufficient to support the root-induced decomposition activities of fungal decomposers, resulting in positive RPEs. The findings suggest that RPEs, promoted by root stimulation of distinct subsets of the microbial community, can either contribute to conserving the soil C stock or to depleting it, depending on plant species and soil N availability. A free Plain Language Summary can be found within the Supporting Information of this article.
(Less)
- author
- Li, Jian LU ; Alaei, Saeed LU ; Zhou, Moyan and Bengtson, Per LU
- organization
- publishing date
- 2021-06-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- bacterial growth, decomposition, fungal growth, gross nitrogen mineralization, rhizosphere priming effects, root exudation, soil enzymes, soil organic matter
- in
- Functional Ecology
- volume
- 35
- issue
- 6
- pages
- 13 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:85107549416
- ISSN
- 0269-8463
- DOI
- 10.1111/1365-2435.13797
- language
- English
- LU publication?
- yes
- id
- caeee890-f0d2-495e-87ab-4e7a7493129a
- date added to LUP
- 2021-06-29 10:12:47
- date last changed
- 2024-05-05 08:00:42
@article{caeee890-f0d2-495e-87ab-4e7a7493129a,
abstract = {{<p>The rhizosphere priming effect (RPE) is increasingly considered an important regulator of below-ground C and N cycling, with implications for terrestrial ecosystem feedback to global change. Even so, there is a lack of knowledge about the mechanisms underlying RPEs. We used novel stable isotope probing methods to investigate RPEs in an experiment with Scots pine and Norway spruce seedlings, two of the most common boreal forest species. We determined root exudation rates, RPEs on SOM decomposition and gross N mineralization, and the contribution of different microbial functional groups to the observed RPEs. Pine induced positive and spruce induced negative RPEs on SOM decomposition, while no RPE on gross N mineralization was observed. Negative RPEs in the spruce treatment were attributed to an opportunistic subset of the fungal community that was growing on root-derived <sup>13</sup>C while depleting available N, thus reducing the activity of microbial SOM decomposers. In the pine treatment, available N was likely sufficient to support the root-induced decomposition activities of fungal decomposers, resulting in positive RPEs. The findings suggest that RPEs, promoted by root stimulation of distinct subsets of the microbial community, can either contribute to conserving the soil C stock or to depleting it, depending on plant species and soil N availability. A free Plain Language Summary can be found within the Supporting Information of this article.</p>}},
author = {{Li, Jian and Alaei, Saeed and Zhou, Moyan and Bengtson, Per}},
issn = {{0269-8463}},
keywords = {{bacterial growth; decomposition; fungal growth; gross nitrogen mineralization; rhizosphere priming effects; root exudation; soil enzymes; soil organic matter}},
language = {{eng}},
month = {{06}},
number = {{6}},
pages = {{1312--1324}},
publisher = {{Wiley-Blackwell}},
series = {{Functional Ecology}},
title = {{Root influence on soil nitrogen availability and microbial community dynamics results in contrasting rhizosphere priming effects in pine and spruce soil}},
url = {{http://dx.doi.org/10.1111/1365-2435.13797}},
doi = {{10.1111/1365-2435.13797}},
volume = {{35}},
year = {{2021}},
}