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Influence of temperature and soil drying on respiration of individual roots in citrus: integrating greenhouse observations into a predictive model for the field

Bryla, D.R. and Bouma, T.J. and Hartmond, U. and Eissenstat, D.M. (2001) Influence of temperature and soil drying on respiration of individual roots in citrus: integrating greenhouse observations into a predictive model for the field. Plant Cell and Environment, 24, 781-790. ISSN 0140-7791.

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Official URL: http://dx.doi.org/10.1046/j.1365-3040.2001.00723.x

Abstract

In citrus, the majority of fine roots are distributed near the soil surface - a region where conditions are frequently dry and temperatures fluctuate considerably. To develop a better understanding of the relationship between changes in soil conditions and a plant's below-ground respiratory costs, the effects of temperature and soil drying on citrus root respiration were quantified in controlled greenhouse experiments. Chambers designed for measuring the respiration of individual roots were used. Under moist soil conditions, root respiration in citrus increased exponentially with changes in soil temperature (Q(10) = 1.8-2.0), provided that the changes in temperature were short-term. However, when temperatures were held constant, root respiration did not increase exponentially with increasing temperatures. Instead, the roots acclimated to controlled temperatures above 23 degreesC, thereby reducing their metabolism in warmer soils. Under drying soil conditions, root respiration decreased gradually beginning at 6% soil water content and reached a minimum at <2% soil water content in sandy soil. A model was constructed from greenhouse data to predict diurnal patterns of fine root respiration based on temperature and soil water content. The model was then validated in the field using data obtained by CO2 trapping on root systems of mature citrus trees. The trees were grown at a site where the soil temperature and water content were manipulated. Respiration predicted by the model was in general agreement with observed rates, which indicates the model may be used to estimate entire root system respiration for citrus. [KEYWORDS: root distribution, simulation, soil water content, temperature]

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:10985
Deposited On:24 Nov 2011 01:00
Last Modified:31 Mar 2014 10:47

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