Drought changes the structure and elemental composition of very fine roots in seedlings of ten woody tree species. Implications for a drier climate
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Background and aims
Water availability is often one of the most limiting factors for plants. Climate change predictions for many areas suggest an intensification of water limitation. The ability of a plant to modify its root characteristics can be an important mechanism for preventing drought stress.
We studied the drought response of seedlings of 10 woody species and compared the biomass allocation, vertical root distribution across different root diameters, and the key traits of very fine roots (root diameter <0.5 mm) under two water regimes (no water limitation and severe drought).
Under drought conditions, the very fine roots had a higher specific root length (SRL, root length: biomass ratio), smaller root diameter and higher root tissue mass density, as well as a lower nitrogen concentration. A higher value of the mean root plasticity index was related to higher drought resistance. A quantitative literature review showed that there was a wide variation in the effect of the drought on SRL, thus there was not a clear effect of drought on SRL.
Certain species have the necessary root traits and plasticity to survive drought. We have identified plasticity in root characteristics as a whole-plant trait which plays a significant role in separating out species into those which are vulnerable and those which are resistant to drought.
KeywordsBiomass allocation Drought Plasticity Vertical root distribution Root traits Specific root length Survival
This study was supported by an FPI-MEC pre-doctoral fellowship awarded to BL (BES-2009-016985), the coordinated Spanish MEC projects INTERBOS (CGL2008-04503-CO3-02) and DIVERBOS (CGL2011-30285-C02-02), the ANASINQUE project (PGC2010-RNM-5782), the Life + Biodehesa Project (11/BIO/ES/000726) and FEDER funding. We thank the Consejería de Medio Ambiente (Junta de Andalucía, Spain) for providing the seedlings for this experiment. Mar Ávila and Daniel Sánchez helped in the experiment and Simón Cuadros let us use the WinRHIZO analysis equipment. Thanks to Enrique Garcia de la Riva and José Luis Quero for their comments aimed at improving the manuscript. Our research group is a member of the GLOBIMED network (http://www.globimed.net/).
- AEMET. Agencia Estatal de Meteorologia. (Spain). http://www.aemet.es/es/serviciosclimaticos/datosclimatologicos (accessed 29 September 2012).
- Allen CD, Macalady AK, Chenchouni H, Bachelet D, McDowell N, Vennetier M, Kitzberger T, Rigling A, Breshears DD, Hogg E, Gonzalez P, Fensham R, Zhang Z, Castro J, Demidova N, Lim J, Allard G, Running SW, Semerci A, Cobb N (2010) A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests. Forest Ecol Manag 259:660–684CrossRefGoogle Scholar
- Auclair AND (1993) Extreme climatic fluctuations as a cause of forest dieback in the Pacific rim. Water Air Soil Pollut 66:207–229Google Scholar
- Baburai N (2006) The physiological and genetic bases of water-use efficiency in winter wheat. PhD Thesis, Nottingham, University of Nottingham, UK.Google Scholar
- Blum A (2002) Drought tolerance is it a complex trait? In: Saxena NP, O’Toole JC (eds) Field screening for drought tolerance in crop plants with emphasis on rice. New York, ICRISAT and The Rockefeller Foundation, pp 17–22Google Scholar
- Ciais P, Reichstein M, Viovy N, Granier A, Ogée J, Allard V, Buchmann N, Aubinet M, Bernhofer C, Carrara A, Chevallier F, De Noblet N, Friend A, Friedlingstein P, Gobron N, Grünwald T, Heinesch B, Keronen P, Knohl A, Krinner G, Loustau D, Manca G, Matteucci G, Miglietta F, Ourcival JM, Pilegaard K, Rambal S, Seufert G, Soussana JF, Sanz MJ, Schulze ED, Vesala T, Valentini R (2005) Europe-wide reduction in primary productivity caused by the heat and drought in 2003. Nature 437:529–533PubMedCrossRefGoogle Scholar
- Ebrahim NM (2008) Responses of root and shoot growth of durum wheat (Triticum turgidum) and barley (Hordeum vulgare) plants to different water and nitrogen levels. PhD Thesis, University of Jordan, Amman, JordanGoogle Scholar
- Fitter AH (1985) Functional significance of root morphology and root system architecture. In: Fitter AH, Atkinson D, Read DJ, Usher MB (eds) Ecological Interactions in Soil. Blackwell Scientific Publications, Oxford, pp 87–106Google Scholar
- Grime JP, Crick JC, Rincon JC (1986) The ecological significance of plasticity. In: Trewavas AJ (ed) Plasticity in Plants. Cambridge University, Cambridge, pp 5–29Google Scholar
- Kramer PJ, Boyer JS (1995) Water relations of plants and soils. Academic, San DiegoGoogle Scholar
- López González GA (2001) Los árboles y arbustos de la Peninsula Iberica e Islas Baleares: especies silvestres y las principales cultivadas. Mundi-Prensa, MadridGoogle Scholar
- Mokany K, Raison RJ, Prokushkin AS (2006) Critical analysis of root:shoot ratios in terrestrial biomes. Glob Chang Biol 11:1–13Google Scholar
- Nicotra AB, Babicka N, Westoby M (2002) Seedling root anatomy and morphology: an examination of ecological differentiation with rainfall using phylogenetically independent contrasts. Oecologia 130:136–145Google Scholar
- Palátová E (2002) Effect of increased nitrogen depositions and drought stress on the development of Scots pine (Pinus sylvestris) – II. Root system response. J Forensic Sci 48:237–247Google Scholar
- Ryser P (1998) Intra– and interspecific variation in root length, root turnover and the underlying parameters. In: Lambers H, Poorter H, van Vuuren MMI (eds) Variation in plant growth. Backhuys Publishers, Leiden, pp 441–465Google Scholar
- Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (2007) IPCC climate change 2007. In: The physical science basis. Cambridge University Press, CambridgeGoogle Scholar
- Taiz L, Zeiger E (2006) Plant physiology, 4th edn. Sinauer Associates Inc. Publishers, Sunderland, p 764Google Scholar
- Zhu WQ, Wu LH, Tao QN (2002) Advances in the studies on crop root against drought stress. Soil Environ 11:430–433Google Scholar