Aluminum toxicity to tropical montane forest tree seedlings in southern Ecuador: response of biomass and plant morphology to elevated Al concentrations

• Published in: Plant and soil Vol. 382; no. 1-2; pp. 301 - 315
• Main Authors: Rehmus, Agnes, Bigalke, Moritz, Valarezo, Carlos, Castillo, Julio Mora, Wilcke, Wolfgang
• Format: Journal Article
• Language: English
• Published: Cham Springer-Verlag 01.09.2014; Springer; Springer International Publishing; Springer Nature B.V
• Subjects: Agronomy. Soil science and plant productions; Aluminum; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Botany; Cedrela odorata; Chemical, physicochemical, biochemical and biological properties; Contamination; dose response; Ecology; Environmental aspects; Forest soils; Forest trees; Forestry research; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Handroanthus chrysanthus subsp. chrysanthus; Health aspects; Hydroponics; Indigenous species; Leachates; Leaf area; Life Sciences; montane forests; Morphology; Mountain forests; Nutrient concentrations; Organic foods; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Phytotoxicity; pioneer species; Plant growth; Plant morphology; Plant Physiology; Plant roots; Plant Sciences; Plant species; Plant-soil relationships; Plants; primary productivity; Regular Article; Seedlings; Seeds; shoots; Soil science; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Tabebuia; Toxicity; Trees; Tropical forests; Ecuador; South America; America; Dose-response curves; Organic layer leachate; Aluminum toxicity; Tropical forest tree seedlings; Organic matter; Toxicity; Plant juvenile growth stage; Tropical zone; Physical environment; Biomass; Dose activity relation; Mountain; Developmental stage; Intertropical zone; Forest tree; Response curve; Aluminium; Tropical forest; Woody plant; Concentration; Tropical montane forest; Response; Morphology; Soil plant relation; Leachate; Mountain forest
• DOI: 10.1007/s11104-014-2110-0
• ISSN: 0032-079X

AIMS: In acid tropical forest soils (pH <5.5) increased mobility of aluminum might limit aboveground productivity. Therefore, we evaluated Al phytotoxicity of three native tree species of tropical montane forests in southern Ecuador. METHODS: An hydroponic dose-response experiment was conducted. Seedlings of Cedrela odorata L., Heliocarpus americanus L., and Tabebuia chrysantha (Jacq.) G. Nicholson were treated with 0, 300, 600, 1200, and 2400 μ M Al and an organic layer leachate. Dose-response curves were generated for root and shoot morphologic properties to determine effective concentrations (EC). RESULTS: Shoot biomass and healthy leaf area decreased by 44 % to 83 % at 2400 μ M Al, root biomass did not respond (C. odorata), declined by 51 % (H. americanus), or was stimulated at low Al concentrations of 300 μ M (T. chrysantha). EC10 (i.e. reduction by 10 %) values of Al for total biomass were 315 μ M (C. odorata), 219 μ M (H. americanus), and 368 μ M (T. chrysantha). Helicarpus americanus, a fast growing pioneer tree species, was most sensitive to Al toxicity. Negative effects were strongest if plants grew in organic layer leachate, indicating limitation of plant growth by nutrient scarcity rather than Al toxicity. CONCLUSIONS: Al toxicity occurred at Al concentrations far above those in native organic layer leachate.