Deep tritiated water uptake and predawn xylem water potentials as indicators of vertical rooting extent in a Quercus–Carya forest

1989 ◽  
Vol 19 (5) ◽  
pp. 627-631 ◽  
Author(s):  
Jeffrey W. Stringer ◽  
Paul J. Kalisz ◽  
John A. Volpe
Keyword(s):  
Water Uptake ◽  
Deep Water ◽  
Tritiated Water ◽  
Water Source ◽  
Growing Season ◽  
Surface Soils ◽  
Water Potentials ◽  
Second Growth ◽  
Highly Correlated ◽  
Fractured Sandstone

Transpiration uptake from a tritiated water source (3H2O) associated with a sandstone bed at 3 m depth was examined in a second-growth Quercus–Carya forest. The effect of utilization of deep water on predawn xylem water potentials (Pstem) was also investigated. The 3H2O saturated the soil contacting the sandstone bed. As surface soils dried during the growing season, 3H2O uptake increased. Although all trees growing over the 3H2O reserve were capable of utilizing some of this water, Q. alba trees from all canopy levels generally exhibited higher foliage tritium (3H) activities than C. glabra (Mill.) Sweet. Higher (less negative) Pstem values were associated with trees having higher foliage 3H activities. The Q. alba tree with the highest foliage 3H activity, 1.2 × 106 Bq•L−1, exhibited the highest Pstem value, −0.875 MPa; the Q. alba tree with the lowest 3H activity also had the lowest Pstem value, 4.5 × 104 Bq•L−1 and −1.75 MPa, respectively. Pstem and the logarithm of 3H activity were highly correlated (r2 = 0.89), suggesting that predawn moisture status was at least partially controlled by the ability of trees to utilize the deep water reserve at or near the fractured sandstone bed.

scholarly journals Chicory demonstrates substantial water uptake from below 2 m depth, but still did not escape topsoil drought

2018 ◽  
Author(s):  
Camilla Ruø Rasmussen ◽  
Kristian Thorup-Kristensen ◽  
Dorte Bodin Dresbøll
Keyword(s):  
Water Uptake ◽  
Deep Water ◽  
Resource Competition ◽  
Root Zone ◽  
Growing Season ◽  
Agricultural Crops ◽  
Deep Soil ◽  
Deep Roots ◽  
Lolium Perenne L ◽  
Medicago Lupulina

AbstractAimsDeep-rooted agricultural crops can potentially utilize deep water pools and thus reduce periods where growth is water limited. Chicory (Cichorium intybus L.) is known to be deep-rooted, but the contribution of deep roots to water uptake under well-watered and drought conditions by the deep root system has not been studied. The aim of this study was to investigate whether chicory could reach 3 m depth within a growing season and demonstrate significant water uptake from the deeper part of the root zone.MethodsWe tested if chicory exposed to either topsoil drought or resource competition from the shallow-rooted species ryegrass (Lolium perenne L.) and black medic (Medicago lupulina L.) would increase deep water uptake in compensation for reduced topsoil water uptake. We grew chicory in 4 m deep soil filled rhizotrons and found that the roots reached 3 m depth within a growing season.ResultsWater uptake from below 1.7 m depth in 2016 and 2.3 m depth in 2017 contributed significantly to chicory water use. However, neither drought nor intercropping increased the deep water uptake.ConclusionChicory benefits from being deep-rooted during drought events, yet deep water uptake cannot compensate for the reduced topsoil water uptake during drought.

scholarly journals Importance of deep water uptake in tropical eucalypt forest

2016 ◽  
Vol 31 (2) ◽  
pp. 509-519 ◽  
Author(s):  
Mathias Christina ◽  
Yann Nouvellon ◽  
Jean‐Paul Laclau ◽  
Jose L. Stape ◽  
Jean‐Pierre Bouillet ◽  
...  
Keyword(s):  
Water Uptake ◽  
Deep Water ◽  
Eucalypt Forest

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.

Water balance changes in a crop sequence with lucerne

2001 ◽  
Vol 52 (2) ◽  
pp. 247 ◽  
Author(s):  
F. X. Dunin ◽  
C. J. Smith ◽  
S. J. Zegelin ◽  
R. Leuning
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Soil Depth ◽  
Water Storage ◽  
Growing Season ◽  
Soil Water Storage ◽  
Annual Rainfall ◽  
Root Extension ◽  
Annual Crops ◽  
Lower Productivity

In a detailed study of soil water storage and transport in a sequence of 1 year wheat and 4 years of lucerne, we evaluated drainage under the crop and lucerne as well as additional soil water uptake achieved by the subsequent lucerne phase. The study was performed at Wagga Wagga on a gradational clay soil between 1993 and 1998, during which there was both drought and high amounts of drainage (>10% of annual rainfall) from the rotation. Lucerne removed an additional 125 mm from soil water storage compared with wheat (root-zone of ~1 m), leading to an estimated reduction in drainage to 30–50% of that of rotations comprising solely annual crops and/or pasture. This additional soil water uptake by lucerne was achieved through apparent root extension of 2–2.5 m beyond that of annual crops. It was effective in generating a sink for soil water retention that was about double that of annual crops in this soil. Successful establishment of lucerne at 30 plants/m2 in the first growing season of the pasture phase was a requirement for this root extension. Seasonal water use by lucerne tended to be similar to that of crops in the growing season between May and September, because plant water uptake was confined to the top 1 m of soil. Uptake of water from the subsoil was intermittent over a 2-year period following its successful winter establishment. In each of 2 annual periods, uptake below 1 m soil depth began late in the growing season and terminated in the following autumn. Above-ground dry matter production of lucerne was lower than that by crops grown in the region despite an off-season growth component that was absent under fallow conditions following cropping. This apparent lower productivity of lucerne could be traced in part to greater allocation of assimilate to roots and also to late peak growth rates at high temperatures, which incurred a penalty in terms of lower transpiration efficiency. The shortfall in herbage production by lucerne was offset with the provision of timely, high quality fodder during summer and autumn. Lucerne conferred indirect benefits through nitrogen supply and weed control. Benefits and penalties to the agronomy and hydrology of phase farming systems with lucerne are discussed.

Root hairs bridge the gap between roots and soil water

2020 ◽  
Author(s):  
Patrick Duddek ◽  
Mutez Ahmed ◽  
Mohsen Zarebanadkouki ◽  
Nicolai Koebernick ◽  
Goran Lovric ◽  
...  
Keyword(s):  
Water Uptake ◽  
Contact Area ◽  
Geodesic Distance ◽  
Root Hairs ◽  
Root Water Uptake ◽  
Root Surface ◽  
Particle Packing ◽  
Biophysical Properties ◽  
Soil Matrix ◽  
Water Potentials

<p>Although 40% of total terrestrial precipitation transits the rhizosphere, there is still substantive lack of understanding of the rhizosphere biophysical properties and their impact on root water uptake. Our hypothesis is that roots are capable of altering the biophysical properties of the rhizosphere and hereby facilitating root water uptake. In particular, we expect that root hairs maintain the hydraulic contact between roots and soil at low water potentials. We have recently shown that root hairs facilitate root water uptake in dry soils at high transpiration rates. Our explanation was that root hairs extend the effective root radius decreasing the flow velocity at the root surface and hence the drop in matric potential across the rhizosphere.</p><p>To test this hypothesis, we used synchrotron X-ray CT to image the distribution of root hairs in soils. The experiments were conducted with two maize genotypes (with and without root hairs) grown in two soil textures (loam vs sand). Segmenting the different domains within the high-resolution images enabled us to quantify the contact area of the root surface and root hairs with the soil matrix at different water potentials. Furthermore, we calculated the geodesic distance between the root and the soil matrix as a proxy of the accessibility of water to the root.</p><p>The results show that root hairs increase the total root surface by approx. 30% and the contact area with the soil matrix by approx. 40%. Furthermore, the average distance from the soil to the root surface decreases by approx. 40% due to hairs, which is the effect of root hairs preferentially growing through macropores. In summary, root hairs not only increase the root surface and the root-soil contact area, but also bridge the air-filled pores between the root epidermis and the soil matrix, thus facilitating the extraction of water.  On top of that, the segmented CT images are also the basis for image-based models aiming at quantifying root water uptake and the effect of root hairs.</p><p> </p><p> </p><p>References</p><ul><li>(1) Koebernick N, Daly KR, Keyes SD, et al. 2019. Imaging microstructure of the barley rhizosphere: particle packing and root hair influences. New Phytologist 221, 1878–1889.</li> <li>(2) Carminati A, Benard P, Ahmed MA, Zarebanadkouki M. 2017. Liquid bridges at the root-soil interface. Plant and Soil 417, 1–15.</li> </ul><p> </p>

What limits deep water uptake by deep-rooted crops?

2020 ◽  
Author(s):  
Camilla Rasmussen ◽  
Eva Rosenqvist ◽  
Fulai Liu ◽  
Dorte Bodin Dresbøll ◽  
Kristian Thorup-Kristensen ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Water Uptake ◽  
Deep Water ◽  
Large Scale ◽  
Root Zone ◽  
Root Length Density ◽  
Yield Losses ◽  
Deep Soil ◽  
Deep Roots ◽  
Water Limitations

<p>Minimizing water limitation during growth of agricultural crops is crucial to unlocking full yield potentials. Crop yield losses vary according to timing and severity of water limitations, but even short-term droughts can be a major cause of yield losses. While the potential influence of deep roots on water uptake has been highlighted numerous times, the actual contribution of deep roots to water uptake is yet to be revealed. The objective of this study is to get an understanding of what limits deep water uptake by deep-rooted crops under topsoil water limitations.</p><p>We found that deep-rooted crops experience water limitations despite access to water stored in the deep soil and we hypothesize that deep water uptake by deep-rooted crops is limited by 1) the hydraulic conductivity of the deeper part of the root zone, arising from limited root length density in combination with the hydraulic resistance of the roots or 2) by a hormonal response arising from the plant sensing dry conditions in the shallow soil leading to stomata closure, to conserve water. The two hypotheses can of course not be valid simultaneously, but both might be valid under certain conditions, at certain times or for certain species.</p><p>In a large-scale semi-field setup, we grow oil seed rape and by combining measures of root development, root hydraulic conductivity, transpiration, stomatal conductance, ABA concentrations and soil water content from a large scale semi-field setup with a mechanistic 3-D root-soil modelling approach (R-SWMS), we are able to us distinguish various scenarios and to evaluate what limits deep water uptake.</p>

How do meteorological variables and topography control species-specific water uptake strategy along a forested hillslope?

2020 ◽  
Author(s):  
Ginevra Fabiani ◽  
Daniele Penna ◽  
Julian Klaus
Keyword(s):  
Isotopic Composition ◽  
Soil Water ◽  
Water Uptake ◽  
Temporal Dynamics ◽  
Growth Parameters ◽  
Stream Water ◽  
Growing Season ◽  
Grab Sampling ◽  
Spatio Temporal ◽  
Species Specific

<p>In the face of current global warming conditions, temperate forest ecosystems are expected to be strongly affected by temperature increase and more frequent and intense water shortage. This leads to severe stress for forest vegetation in many temperate systems. Therefore, understanding the vegetation water use in temperate forests is urgently needed for more effective forest management strategies. Root water uptake (RWU) is a species-specific trait (tree physiology and root architecture) and its spatio-temporal patterns are controlled by a range of site-specific (e.g., topography, geology, pedology) and meteorological factors (e.g., temperature, soil humidity, rainfall.</p><p>In the present study, we use stable water isotopologues as ecohydrological tracers combined with continuous measurement of hydrometeorological (weather variables, groundwater levels, soil moisture, streamflow) and physiological (sap flow, radial stem growth) parameters to investigate the spatio-temporal dynamics of water uptake for beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl) trees along a hillslope in a Luxemburgish catchment.</p><p>Fortnightly field campaigns were carried out during the growing season (April-October) 2019 to sample water from xylem, soil water at different depths, groundwater, stream water, and precipitation. Soil water isotopic composition and xylem water were extracted via cryogenic distillation. Grab sampling was performed for the other water pools. The isotopic composition was determined through laser spectroscopy and mass spectrometry (for xylem samples only).</p><p>From preliminary results, the isotopic composition of xylem water shows a marked seasonal variability suggesting a plasticity in RWU or a change in the isotopic composition of the water pools over the growing season. Moreover, beech and oak trees exhibit different uptake strategies when water supply is low. Within the range of observed groundwater variation topography does not play a statistically significant role on RWU.</p>

The Synoptic Climatology of Cool-Season Rainfall in the Central Wheatbelt of Western Australia

2012 ◽  
Vol 140 (1) ◽  
pp. 28-43 ◽  
Author(s):  
Michael J. Pook ◽  
James S. Risbey ◽  
Peter C. McIntosh
Keyword(s):  
Large Scale ◽  
Daily Rainfall ◽  
Growing Season ◽  
Synoptic Climatology ◽  
Rainfall Events ◽  
Synoptic Weather ◽  
Proportional Contribution ◽  
Cutoff Low ◽  
Highly Correlated

Abstract Synoptic weather systems form an important part of the physical link between remote large-scale climate drivers and regional rainfall. A synoptic climatology of daily rainfall events is developed for the Central Wheatbelt of southwestern Australia over the April–October growing season for the years 1965–2009. The climatology reveals that frontal systems contribute approximately one-half of the rainfall in the growing season while cutoff lows contribute about a third. The ratio of frontal rainfall to cutoff rainfall varies throughout the growing season. Cutoff lows contribute over 40% of rainfall in the austral autumn and spring, but this falls to about 20% in August when frontal rainfall climbs to more than 60%. The number of cutoff lows varies markedly from one growing season to another, but does not exhibit a significant long-term trend. The mean rainfall per cutoff system is also highly variable, but has gradually declined over the analysis period, particularly in the past decade. The decline in rainfall per frontal system is less significant. Cutoff low rainfall has contributed more strongly in percentage terms to the recent decline in rainfall in the Central Wheatbelt than the frontal component and accounts for more than half of the overall trend. Atmospheric blocking is highly correlated with rainfall in the region where cutoff low rainfall makes its highest proportional contribution. Hence, the decline in rain from cutoff low systems is likely to have been associated with changes in blocking and the factors controlling blocking in the region.

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