Analyzing relationships among water uptake patterns, rootlet biomass distribution and soil water content profile in a subalpine shrubland using water isotopes

Liu, Yuhong; Xu, Zhen; Duffy, Rodney; Chen, Wenlian; An, Shuqing; Liu, Shirong; Liu, Fude

doi:10.1016/j.ejsobi.2011.07.012

Cited by 53 publications

(41 citation statements)

References 33 publications

(57 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As discussed in [10], other authors have found the soil-water fluxes to be controlled by top layers, for instance [39][40][41]. The importance of top layers for dryland forests is based on maximizing the uptake of ephemeral water pulses from rainfall, together with an optimization of nutrient cycling [42][43][44].…”

Section: General Hydrological Featuresmentioning

confidence: 97%

Hydrology of a Water‐Limited Forest under Climate Change Scenarios: The Case of the Caatinga Biome, Brazil

Pinheiro

Lier

Bezerra

2017

Forests

View full text Add to dashboard Cite

Given the strong interactions between climate and vegetation, climate change effects on natural and agricultural ecosystems are common objects of research. Reduced water availability is predicted to take place across large regions of the globe, including Northeastern Brazil. The Caatinga, a complex tropical water-limited ecosystem and the only exclusively Brazilian biome, prevails as the main natural forest of this region. The aim of this study was to examine the soil-water balance for this biome under a climate-warming scenario and with reduced rainfall. Climate change projections were assessed from regional circulation models earlier applied to the Brazilian territory. A statistical climate data generator was used to compose a synthetic weather dataset, which was later integrated into a hydrological model. Compared to simulations with current climate for the same site, under the scenario with climate change, transpiration was enhanced by 36%, and soil-water evaporation and interception were reduced by 16% and 34%, respectively. The greatest change in soil-water components was observed for deep drainage, accounting only for 2% of the annual rainfall. Soil-plant-atmosphere fluxes seem to be controlled by the top layer (0.0-0.2 m), which provides 80% of the total transpiration, suggesting that the Caatinga forest may become completely soil-water pulse dominated under scenarios of reduced water availability.

show abstract

Section: General Hydrological Featuresmentioning

confidence: 97%

Hydrology of a Water‐Limited Forest under Climate Change Scenarios: The Case of the Caatinga Biome, Brazil

Pinheiro

Lier

Bezerra

2017

Forests

View full text Add to dashboard Cite

show abstract

“…However, one of the ways by which soil loses water is plant root uptake, water uptake and transport through the root system have been described as passive processes (Mendel et al, 2003). Therefore, fractionation of stable isotopes of water does not occur during root uptake as evaporation of soil waters takes place before they have been taken up by plants (Liu et al, 2011). Field observations of d 18 O and dD enrichments of soil water near the surface due to evaporation has been reported by many authors (Gazis and Feng, 2004;Robertson and Gazis, 2006).…”

Section: Introductionmentioning

confidence: 99%

Estimation of soil water evaporative loss after tillage operation using the stable isotope technique

Busari¹,

Salako²,

Tuniz³

et al. 2013

International Agrophysics

View full text Add to dashboard Cite

A b s t r a c t. Application of stable isotopes in soil studies has improved quantitative evaluation of evaporation and other hydrological processes in soil. This study was carried out to determine the effect of tillage on evaporative loss of water from the soil. Zero tillage and conventional tillage were compared. Suction tubes were installed for soil water collection at the depths 0.15, 0.50, and 1.0 m by pumping soil water with a peristaltic pump. Soil water evaporation was estimated using stable isotopes of water. The mean isotopic composition of the soil water at 0.15 m soil depth were -1.15‰ (d 18 O) and -0.75‰ (dD) and were highly enriched compared with the isotopic compositions of the site precipitation. Soil water stable isotopes (d 18 O and dD) were more enriched near the surface under zero tillage while they were less negative down the profile under zero tillage. This suggests an occurrence of more evaporation and infiltration under conventional then zero tillage, respectively, because evaporative fractionation contributes to escape of lighter isotopes from liquid into the vapour phase leading to enrichment in heavy isotopes in the liquid phase. The annual evaporation estimated using the vapour diffusion equation ranges from 46-70 and 54-84 mm year -1 under zero and conventional tillage, respectively, indicating more evaporation under conventional tillage compared with zero tillage. Therefore, to reduce soil water loss, adoption of conservation tillage practices such as zero tillage is encouraged.K e y w o r d s: evaporative loss, tillage, isotopic fractionation, isotope technique INTRODUCTIONTillage is mechanical manipulation of the soil for the purpose of crop production and it affects significantly soil characteristics such as soil water conservation, soil temperature, infiltration and evapotranspiration processes. As tillage is known to cause soil surface disruption, fractionation of stable isotopes following soil tillage has been documented (Angela et al., 2009). Although tilled plots may have very high initial infiltration rate values, these rates rapidly decline with time (Guzha, 2004) probably due to intense alteration of the top centimetres of the soil (Josa et al., 2010) and rapid structural deterioration caused by slaking and dispersion. However, due to the effect of increased soil organic matter (Lipiec et al., 2006) and soil surface protection, high infiltration under zero tilled (ZT) plots have been documented (Shukla et al., 2003). According to Gupta et al. (2004) less intense tillage keeps the crop residue at the soil surface, thereby increasing the activity of surface-feeding earthworms, leaving the root channels undisturbed, leading to the presence of numerous surface-connected macro-pores and inter-pedal, hence higher infiltration. It has been reported that lower soil temperature due to higher water content in the topsoil and more plant residues on the soil surface under ZT usually result in reduced evaporation, whereas the opening of topsoil enhances evaporation from the tille...

show abstract

“…The naturally occurring vertical gradients of δD and δ 18 O in soil water provide similar information about plant water uptake depth from soils. A number of studies have used isotopes to characterize soil water movement in one location and thus one climatic regime (Orlowski et al, 2016b;Manzoni et al, 2013;Liu et al, 2011;Stumpp et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Soil water migration in the unsaturated zone of semiarid region in China from isotope evidence

Yang

2017

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Soil water is an important driving force of the ecosystems, especially in the semiarid hill and gully region of the northwestern Loess Plateau in China. The mechanism of soil water migration in the reconstruction and restoration of Loess Plateau is a key scientific problem that must be solved. Isotopic tracers can provide valuable information associated with complex hydrological problems, difficult to obtain using other methods. In this study, the oxygen and hydrogen isotopes are used as tracers to investigate the migration processes of soil water in the unsaturated zone in an arid region of China's Loess Plateau. Samples of precipitation, soil water, plant xylems and plant roots are collected and analysed. The conservative elements deuterium (D) and oxygen ( 18 O) are used as tracers to identify variable source and mixing processes. The mixing model is used to quantify the contribution of each end member and calculate mixing amounts. The results show that the isotopic composition of precipitation in the Anjiagou River basin is affected by isotopic fractionation due to evaporation. The isotopic compositions of soil waters are plotted between or near the local meteoric water lines, indicating that soil waters are recharged by precipitation. The soil water migration is dominated by piston-type flow in the study area and rarely preferential flow. Water migration exhibited a transformation pathway from precipitation to soil water to plant water. δ 18 O and δD are enriched in the shallow (< 20 cm depth) soil water in most soil profiles due to evaporation. The isotopic composition of xylem water is close to that of soil water at the depth of 40-60 cm. These values reflect soil water signatures associated with Caragana korshinskii Kom. uptake at the depth of 40-60 cm. Soil water from the surface soil layer (20-40 cm) comprised 6-12 % of plant xylem water, while soil water at the depth of 40-60 cm is the largest component of plant xylem water (ranging from 60 to 66 %), soil water below 60 cm depth comprised 8-14 % of plant xylem water and only 5-8 % is derived directly from precipitation. This study investigates the migration process of soil water, identifies the source of plant water and finally provides a scientific basis for identification of model structures and parameters. It can provide a scientific basis for ecological water demand, ecological restoration, and management of water resources.

show abstract

Analyzing relationships among water uptake patterns, rootlet biomass distribution and soil water content profile in a subalpine shrubland using water isotopes

Cited by 53 publications

References 33 publications

Hydrology of a Water‐Limited Forest under Climate Change Scenarios: The Case of the Caatinga Biome, Brazil

Hydrology of a Water‐Limited Forest under Climate Change Scenarios: The Case of the Caatinga Biome, Brazil

Estimation of soil water evaporative loss after tillage operation using the stable isotope technique

Soil water migration in the unsaturated zone of semiarid region in China from isotope evidence

Contact Info

Product

Resources

About