Shifts in leaf N: P stoichiometry during rehabilitation in highly alkaline bauxite processing residue sand
Description
Large quantities of sodic and alkaline bauxite residue are produced globally as a by-product from alumina refineries. Ecological stoichiometry of key elements [nitrogen (N) and phosphorus (P)] plays a critical role in establishing vegetation cover in bauxite residue sand (BRS). Here we examined how changes in soil chemical properties over time in rehabilitated sodic and alkaline BRS affected leaf N to P stoichiometry of native species used for rehabilitation. Both Ca and soil pH influenced the shifts in leaf N:P ratios of the study species as supported by consistently significant positive relationships (P < 0.001) between these soil indices and leaf N:P ratios. Shifts from N to P limitation were evident for N-fixing species, while N limitation was consistently experienced by non-N-fixing plant species. In older rehabilitated BRS embankments, soil and plant indices (Ca, Na, pH, EC, ESP and leaf N:P ratios) tended to align with those of the natural ecosystem, suggesting improved rehabilitation performance. These findings highlight that leaf N:P stoichiometry can effectively provide a meaningful assessment on understanding nutrient limitation and productivity of native species used for vegetating highly sodic and alkaline BRS, and is a crucial indicator for assessing ecological rehabilitation performance.
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2015-10-07
Agent
- Author (aut): Goloran, Johnvie B.
- Author (aut): Chen, Chengrong
- Author (aut): Phillips, Ian R.
- Author (aut): Elser, James
- Contributor (ctb): College of Liberal Arts and Sciences
- Contributor (ctb): School of Life Sciences