Differential Use of Spatially Heterogeneous Soil Moisture by Two Semiarid Woody Species: Pinus Edulis and Juniperus Monosperma

1997 ◽  
Vol 85 (3) ◽  
pp. 289 ◽  
Author(s):  
David D. Breshears ◽  
Orrin B. Myers ◽  
Susan R. Johnson ◽  
Clifton W. Meyer ◽  
Scott N. Martens
Keyword(s):  
Soil Moisture ◽  
Woody Species ◽  
Pinus Edulis ◽  
Juniperus Monosperma ◽  
Heterogeneous Soil

scholarly journals Non-stationarity of electrical resistivity and soil moisture relationship in heterogeneous soil system: a case study

2015 ◽  
Vol 2 (2) ◽  
pp. 955-994
Author(s):  
D. Michot ◽  
Z. Thomas ◽  
I. Adam
Keyword(s):  
Electrical Resistivity ◽  
Soil Moisture ◽  
Root Zone ◽  
Spatial Scales ◽  
Geophysical Methods ◽  
Matric Potential ◽  
Soil System ◽  
Retention Curve ◽  
Heterogeneous Soil ◽  
Change In Mean

Abstract. Root uptake is the most decisive key in water transfer involving soil and vegetation. It depends on water availability which can be evaluated by punctual measurements. Additionally, surface geophysical methods such as Electrical Resistivity Tomography (ERT) provide larger spatial scales. This paper focuses on investigating temporal and spatial soil moisture changes, along a toposequence crossed by a hedgerow, using ERT and punctual measurements. 10 ERT were performed over the studied period for a 28 m long transect and compared to matric potential and groundwater level measurements. Soil Volumetric Water Content (VWC) was predicted using two methods (i) from ER using Waxman and Smits model (ii) and from matric potential using experimental retention curve fitted by Van Genuchten model. Probability Density Functions (Pdfs) of our set of data show that the largest change, in mean values of ER as well as matric potential, was observed in the topsoil layer. We then analyzed the consistency between ER and punctual measurements in this layer by extracting the arrays in the junction between ER grids and punctual measurements. Pdfs of ER maps at each monitoring time (from T01 to T10) were also calculated to select the more contrasted distributions corresponding to the wettest (T06) and driest states (T10). Results of ER were consistent with matric potential measurements with two different behaviors for locations inside and outside the root zone. A strong correlation (r = 0.9) between VWC values from Waxman and Smits model and those obtained from retention curve was observed outside the root zone. The heterogeneous soil system inside the root zone shows a different pattern in this relationship. The shift in the relationship between ER and soil moisture for the locations outside and inside the root zone highlights the non-stationarity in heterogeneous soil system. Such systems were actually related to the high hedgerow root density and also to a particular topographical context (ditch and bank) which is encountered in Brittany and over north-west of Europe.

A general approach for analytically upscaling the exact root water uptake equations despite heterogeneous soil moisture at the soil-root interface

2021 ◽  
Author(s):  
Martin Bouda ◽  
Jan Vanderborght ◽  
Mathieu Javaux
Keyword(s):  
Soil Moisture ◽  
Exact Solutions ◽  
Root System ◽  
Water Uptake ◽  
Grid Cell ◽  
Earth System ◽  
Water Flows ◽  
Heterogeneous Soil ◽  
Soil Moisture Heterogeneity ◽  
Earth System Models

<p>Recent advances in scaling up water flows on root system networks hold promise for improving predictions of water uptake at large scales. These developments are particularly timely, as persistent difficulties in getting Earth system models to accurately represent soil-root water flows, especially under drying or heterogeneous soil moisture conditions, are now a major obstacle describing the water limitation of terrestrial fluxes.</p><p>One recently developed upscaling formalism has been shown to be both free of discretisation error in flow predictions regardless of scale and with computational cost linearly diminishing with the number of soil subdomains considered. What has been missing from this approach, however, is a proven method to apply it generally – i.e. to an arbitrary root system architecture discretised on an arbitrary grid.</p><p>The work presented here demonstrates a general algorithm that can be applied to a wide range of root system architectures (the only assumption being that only one lateral root originates at one point along a parent root) discretised on a grid consisting of a series of soil layers of variable thickness, as is common in Earth system models. It is further shown theoretically that both of these restrictions can in principle be relaxed and that this approach can in principle be extended to conditions of soil moisture heterogeneity – i.e. situations where each root segment in a soil grid cell faces a different water potential at the soil-root interface.</p><p>This work represents both a practical advance bringing broad applicability to this upscaling approach and a major theoretical advance as exact solutions for water uptake under conditions of soil moisture heterogeneity within grid cells were previously unknown. While obtaining exact solutions despite heterogeneity within the grid cell requires a way of finding the overall mean soil water potential faced by the plant, this advance nevertheless points to possible directions of future research for overcoming the major hurdle of soil moisture heterogeneity.</p>

Spectral sensing of foliar water conditions in two co-occurring conifer species: Pinus edulis and Juniperus monosperma

2005 ◽  
Vol 96 (1) ◽  
pp. 108-118 ◽  
Author(s):  
Hugh C. Stimson ◽  
David D. Breshears ◽  
Susan L. Ustin ◽  
Shawn C. Kefauver
Keyword(s):  
Pinus Edulis ◽  
Conifer Species ◽  
Juniperus Monosperma ◽  
Water Conditions ◽  
Spectral Sensing

Linking nonstructural carbohydrate dynamics to gas exchange and leaf hydraulic behavior in Pinus edulis and Juniperus monosperma

2014 ◽  
Vol 206 (1) ◽  
pp. 411-421 ◽  
Author(s):  
David R. Woodruff ◽  
Frederick C. Meinzer ◽  
Danielle E. Marias ◽  
Sanna Sevanto ◽  
Michael W. Jenkins ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Pinus Edulis ◽  
Juniperus Monosperma ◽  
Hydraulic Behavior ◽  
Nonstructural Carbohydrate ◽  
Carbohydrate Dynamics

scholarly journals Variation in allozymes and stomatal size in pinyon (Pinus edulis, Pinaceae), associated with soil moisture

1998 ◽  
Vol 85 (9) ◽  
pp. 1262-1265 ◽  
Author(s):  
Jeffry B. Mitton ◽  
Michael C. Grant ◽  
Ayako Murayama Yoshino
Keyword(s):  
Soil Moisture ◽  
Pinus Edulis ◽  
Stomatal Size

scholarly journals Novel Cosmic Ray Neutron Sensor Accurately Captures Field-Scale Soil Moisture Trends under Heterogeneous Soil Textures

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3038
Author(s):  
Kade D. Flynn ◽  
Briana M. Wyatt ◽  
Kevin J. McInnes
Keyword(s):  
Soil Moisture ◽  
Water Conservation ◽  
Cosmic Ray ◽  
Atmospheric Conditions ◽  
Rainfall Runoff ◽  
Field Scale ◽  
Near Surface ◽  
Heterogeneous Soil ◽  
In Situ Sensors

Soil moisture is a critical variable influencing plant water uptake, rainfall-runoff partitioning, and near-surface atmospheric conditions. Soil moisture measurements are typically made using either in-situ sensors or by collecting samples, both methods which have a small spatial footprint or, in recent years, by remote sensing satellites with large spatial footprints. The cosmic ray neutron sensor (CRNS) is a proximal technology which provides estimates of field-averaged soil moisture within a radius of up to 240 m from the sensor, offering a much larger sensing footprint than point measurements and providing field-scale information that satellite soil moisture observations cannot capture. Here we compare volumetric soil moisture estimates derived from a novel, less expensive lithium (Li) foil-based CRNS to those from a more expensive commercially available 3He-based CRNS, to measurements from in-situ sensors, and to four intensive surveys of soil moisture in a field with highly variable soil texture. Our results indicate that the accuracy of the Li foil CRNS is comparable to that of the commercially available sensors (MAD = 0.020 m3 m−3), as are the detection radius and depth. Additionally, both sensors capture the influence of soil textural variability on field-average soil moisture. Because novel Li foil-based CRNSs are comparable in accuracy to and much less expensive than current commercially available CRNSs, there is strong potential for future adoption by land and water managers and increased adoption by researchers interested in obtaining field-scale estimates of soil moisture to improve water conservation and sustainability.

scholarly journals Splitting the Difference: Heterogeneous Soil Moisture Availability Affects Aboveground and Belowground Reserve and Mass Allocation in Trembling Aspen

2021 ◽  
Vol 12 ◽  
Author(s):  
Ashley T. Hart ◽  
Morgane Merlin ◽  
Erin Wiley ◽  
Simon M. Landhäusser
Keyword(s):  
Soil Moisture ◽  
Root System ◽  
Resource Availability ◽  
Moisture Regime ◽  
Trembling Aspen ◽  
Moisture Availability ◽  
Resource Limited ◽  
Heterogeneous Soil ◽  
Soil Moisture Availability ◽  
The Impact

When exploring the impact of resource availability on perennial plants, artificial treatments often apply conditions homogeneously across space and time, even though this rarely reflects conditions in natural systems. To investigate the effects of spatially heterogeneous soil moisture on morphological and physiological responses, trembling aspen (Populus tremuloides) saplings were used in a split-pot experiment. Following the division of the root systems, saplings were established for a full year and then subjected to either heterogeneous (portion of the root system exposed to non-lethal drought) or homogeneous (whole root system exposed to non-lethal drought or well-watered) treatments. Above- and belowground growth and non-structural carbohydrate (NSC) reserves (soluble sugars and starch) were measured to determine how allocation of reserves and mass between and within organs changed in response to variation in soil moisture availability. In contrast to saplings in the homogeneous drought treatment, which experienced reduced shoot growth, leaf abscission and fine root loss, saplings exposed to the heterogeneous conditions maintained similar aboveground growth and increased root system allocation compared to well-watered saplings. Interestingly under heterogeneous soil moisture conditions, the portion of the root system that was resource limited had no root dieback and increased carbon reserve concentrations, while the portion of the root system that was not resource limited added new roots (30% increase). Overall, saplings subjected to the heterogeneous soil moisture regime over-compensated belowground, both in mass and NSC reserves. These results indicate that the differential allocation of mass or reserves between above- and belowground organs, but also within the root system can occur. While the mechanisms and processes involved in these patterns are not clear, these responses could be interpreted as adaptations and acclimations to preserve the integrity of the entire sapling and suggests that different portions of plant organs might respond autonomously to local conditions. This study provides further appreciation of the complexity of the mechanisms by which plants manage heterogeneous conditions and offers evidence that spatial and temporal variability of resource availability, particularly belowground, needs to be accounted for when extrapolating and modeling stress responses at larger temporal and spatial scales.

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