effects of water availability on root growth and morphology in an Amazon rainforest

• Published in: Plant and soil Vol. 311; no. 1-2; pp. 189 - 199
• Main Authors: Metcalfe, Daniel B, Meir, Patrick, Aragão, Luiz Eduardo O. C, da Costa, Antonio C. L, Braga, Alan P, Gonçalves, Paulo H. L, de Athaydes Silva Junior, Joao, de Almeida, Samuel S, Dawson, Lorna A, Malhi, Yadvinder, Williams, Mathew
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.10.2008; Springer; Springer Netherlands; Springer Nature B.V
• Subjects: Agronomy. Soil science and plant productions; Amazon rainforest; Amazonia; Animal, plant and microbial ecology; Average linear density; Biological and medical sciences; Biomedical and Life Sciences; Drought; Ecology; ecosystems; Effects; Forest soils; Fundamental and applied biological sciences. Psychology; Life Sciences; Moisture; Moisture content; plant available water; Plant growth; Plant Physiology; Plant roots; Plant Sciences; Plants; Rainforests; Regular Article; Root growth; Root length; Root mass growth; Root surface area; Soil moisture; Soil morphology; Soil science; Soil Science & Conservation; Soil types; Soil water; soil water content; Soils; Specific root length; Studies; Surface area; Surface areas; trees; Tropical rain forests; Vegetation; Water availability; Water uptake; Amazon Basin; Amazonia; Root surface area; Specific root length; Amazon rainforest; Root mass growth; Soil water availability; Root length; Root mass growth; Root length; Root surface area; Soil plant relation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-008-9670-9

This study examined how root growth and morphology were affected by variation in soil moisture at four Amazon rainforest sites with contrasting vegetation and soil types. Mean annual site root mass, length and surface area growth ranged between 3-7 t ha⁻¹, 2-4 km m⁻² and 8-12 m² m⁻² respectively. Mean site specific root length and surface area varied between 8-10 km kg⁻¹ and 24-34 m² kg⁻¹. Growth of root mass, length and surface area was lower when soil water was depleted (P < 0.001) while specific root length and surface area showed the opposite pattern (P < 0.001). These results indicate that changes in root length and surface area per unit mass, and pulses in root growth to exploit transient periods of high soil water availability may be important means for trees in this ecosystem to increase nutrient and water uptake under seasonal and longer-term drought conditions.