The effects of oxalates produced by Salsola tragus on the phosphorus nutrition of Stipa pulchra

• Published in: Oecologia Vol. 102; no. 3; p. 265
• Main Authors: Cannon, J P, Allen, E B, Allen, M F, Dudley, L M, Jurinak, J J
• Format: Journal Article
• Language: English
• Published: Germany 01.06.1995
• Subjects: Facilitation; Salsola tragus; Stipa pulchra; Oxalate Phosphorus
• ISSN: 1432-1939
• DOI: 10.1007/BF00329792

Oxalic acid is produced by some species of plants and mycorrhizal fungi and it may solubilize unavailable soil phosphorus (P) bound by cations (Ca , Al , Fe ). Field and greenhouse experiments were conducted to show whether oxalate produced by the annual Salsola tragus or added oxalic acid would solubilize P from the inorganic-bound soil P pool, making it available for uptake by Stipa pulchra. Oxalate could be leached in the laboratory from the senescent canopy of Salsola, and leaching by rainfall was hypothesized to be a source of potential increased soil P under the Salsola canopy. Both oxalate leached from the canopy of Salsola and added oxalic acid increased the availability of soil P in greenhouse experiments. The source of the increase in available soil P in the greenhouse experiment was shown to be the inorganic-bound P pool, as the total P concentration of the soil decreased with increasing oxalate. There were significant increases in Stipa shoot P in response to Salsola leachates and in response to added oxalate in the greenhouse studies. These results suggest an important role for oxalate in P cycling. On disturbed sites where Salsola invades it may act to facilitate the establishment of later seral species like Stipa by creating a nutrient island of available P.