Interactions between species change the uptake of ammonium and nitrate in Abies faxoniana and Picea asperata.

Publisher: Oxford University Press Country of Publication: Canada NLM ID: 100955338 Publication Model: Print Cited Medium: Internet ISSN: 1758-4469 (Electronic) Linking ISSN: 0829318X NLM ISO Abbreviation: Tree Physiol Subsets: MEDLINE

Publication: Oxford : Oxford University Press
Original Publication: Victoria, [B.C.] : Heron Pub., c1986-

Abies* ; Ammonium Compounds* ; Picea*; Ecosystem ; Nitrate Reductases ; Nitrates ; Nitrogen/analysis ; Plant Roots ; Plants ; Soil

Plant nitrogen (N) uptake is affected by plant-plant interactions, but the mechanisms remain unknown. A 15N-labeled technique was used in a pot experiment to analyze the uptake rate of ammonium (NH4+) and nitrate (NO3-) by Abies faxoniana Rehd. et Wils and Picea asperata Mast. in single-plant mode, intraspecific and interspecific interactions. The results indicated that the effects of plant-plant interactions on N uptake rate depended on plant species and N forms. Picea asperata had a higher N uptake rate of both N forms than A. faxoniana, and both species preferred NO3-. Compared with single-plant mode, intraspecific interaction increased NH4+ uptake for A. faxoniana but reduced that for P. asperata, while it did not change NO3- uptake for the two species. The interspecific interaction enhanced N uptake of both N forms for A. faxoniana but did not affect the P. asperata compared with single-plant mode. NH4+ and NO3- uptake rates for the two species were regulated by root N concentration, root nitrate reductase activity, root vigor, soil pH and soil N availability under plant-plant interactions. Decreased NH4+ uptake rate for P. asperata under intraspecific interaction was induced by lower root N concentration and nitrate reductase activity. The positive effects of interspecific interaction on N uptake for A. faxoniana could be determined mainly by positive rhizosphere effects, such as high soil pH. From the perspective of root-soil interactions, our study provides insight into how plant-plant interactions affect N uptake, which can help to understand species coexistence and biodiversity maintenance in forest ecosystems.
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Keywords: interspecific facilitation; nitrogen forms preference; nitrogen uptake plasticity; root traits; soil nitrogen availability

0 (Ammonium Compounds)
0 (Nitrates)
0 (Soil)
EC 1.7.- (Nitrate Reductases)
N762921K75 (Nitrogen)

Date Created: 20211228 Date Completed: 20220713 Latest Revision: 20220825

20250114

10.1093/treephys/tpab175

34962272