Patterns of Root Architecture Adaptation of a Phreatophytic Perennial Desert Plant in a Hyperarid Desert
2013-07-29
Alhagi sparsifolia Shap. (Leguminosae) is a spiny, perennial subshrub whose shoots die in winter and re-sprout again in spring. A. sparsifolia grows in salinized and arid regions in the native ranges of northwestern China.
In arid regions, the rains are irregular and infrequent, sometimes with no rain during several years. Annual precipitation is insignificant for plant growth; and typically no water is stored in the soils down to the capillary fringe. The natural germination of seeds is severely restricted by surface soil water content, so spontaneously emerging seedlings of A. sparsifolia are infrequent. Natural flooding is the only possible approach for regeneration of all occurring plant species.
Estimate of below-ground biomass is more difficult. At the same time, very limited information regarding root growth and production of hyperarid deserts is available. Plant root systems can respond to nutrient availability and distribution by changing the three-dimensional deployment of their root architecture. The aim of this investigation is to better understand the rooting habits of certain hyperarid dwelling plant.
In this study, the year after year variation of root architecture was investigated in a perennial phreatophyte in the controlled condition vegetation situated in the oasis in the Taklamakan Desert with the goal to elucidate their adaptation to hyperarid environment. The whole plants of an indigenous perennial legume A. sparsifolia with intact root systems were excavated at the end of each growing season from 2007 to 2009 and analyzed for architecture, above and belowground biomass, root/shoot ratio, root depth, seed yields and ramet. Changes in water availability were found to have stupendous effects on taproot depth, lateral root length and ramet quantity. Relative to shoot dry weight, taproot depth decreased with increasing water availability. In contrast, lateral root elongation was promoted by higher water availability.
The result was published in South African Journal of Botany in May 2013.
In arid regions, the rains are irregular and infrequent, sometimes with no rain during several years. Annual precipitation is insignificant for plant growth; and typically no water is stored in the soils down to the capillary fringe. The natural germination of seeds is severely restricted by surface soil water content, so spontaneously emerging seedlings of A. sparsifolia are infrequent. Natural flooding is the only possible approach for regeneration of all occurring plant species.
Estimate of below-ground biomass is more difficult. At the same time, very limited information regarding root growth and production of hyperarid deserts is available. Plant root systems can respond to nutrient availability and distribution by changing the three-dimensional deployment of their root architecture. The aim of this investigation is to better understand the rooting habits of certain hyperarid dwelling plant.
In this study, the year after year variation of root architecture was investigated in a perennial phreatophyte in the controlled condition vegetation situated in the oasis in the Taklamakan Desert with the goal to elucidate their adaptation to hyperarid environment. The whole plants of an indigenous perennial legume A. sparsifolia with intact root systems were excavated at the end of each growing season from 2007 to 2009 and analyzed for architecture, above and belowground biomass, root/shoot ratio, root depth, seed yields and ramet. Changes in water availability were found to have stupendous effects on taproot depth, lateral root length and ramet quantity. Relative to shoot dry weight, taproot depth decreased with increasing water availability. In contrast, lateral root elongation was promoted by higher water availability.
The result was published in South African Journal of Botany in May 2013.