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Effects of mycorrhizal colonization on biomass production and nitrogen fixation of black locust ( Robinia pseudoacacia ) seedlings grown under elevated atmospheric carbon dioxide
Author(s) -
OLESNIEWICZ KIRSTEN S.,
THOMAS RICHARD B.
Publication year - 1999
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.1999.00372.x
Subject(s) - robinia , nitrogen fixation , biology , botany , symbiosis , biomass (ecology) , mycorrhiza , agronomy , horticulture , bacteria , genetics
Interactive effects of elevated atmospheric CO 2 and arbuscular mycorrhizal (AM) fungi on biomass production and N 2 fixation were investigated using black locust ( Robinia pseudoacacia ). Seedlings were grown in growth chambers maintained at either 350 μmol mol −1 or 710 μmol mol −1 CO 2 . Seedlings were inoculated with Rhizobium spp. and were grown with or without AM fungi. The 15 N isotope dilution method was used to determine N source partitioning between N 2 fixation and inorganic fertilizer uptake. Elevated atmospheric CO 2 significantly increased the percentage of fine roots that were colonized by AM fungi. Mycorrhizal seedlings grown under elevated CO 2 had the greatest overall plant biomass production, nodulation, N and P content, and root N absorption. Additionally, elevated CO 2 levels enhanced nodule and root mass production, as well as N 2 fixation rates, of non‐mycorrhizal seedlings. However, the relative response of biomass production to CO 2 enrichment was greater in non‐mycorrhizal seedlings than in mycorrhizal seedlings. This study provides strong evidence that arbuscular mycorrhizal fungi play an important role in the extent to which plant nutrition of symbiotic N 2 ‐fixing tree species is affected by enriched atmospheric CO 2 .