Hydraulic redistribution in dwarf Rhizophora mangle trees driven by interstitial soil water salinity gradients: impacts on hydraulic architecture and gas exchange

2009 ◽  
Vol 29 (5) ◽  
pp. 697-705 ◽  
Author(s):  
G.-Y. Hao ◽  
T. J. Jones ◽  
C. Luton ◽  
Y.-J. Zhang ◽  
E. Manzane ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Rhizophora Mangle ◽  
Water Salinity ◽  
Hydraulic Redistribution ◽  
Hydraulic Architecture ◽  
Salinity Gradients

Growth and leaf gas exchange in Populus euphratica across soil water and salinity gradients

2013 ◽  
Vol 51 (3) ◽  
pp. 321-329 ◽  
Author(s):  
J. Y. Li ◽  
C. Y. Zhao ◽  
J. Li ◽  
Y. Y. Yan ◽  
B. Yu ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Leaf Gas Exchange ◽  
Populus Euphratica ◽  
Salinity Gradients

A simple numerical model to estimate water availability in saline soils

Soil Research ◽  
2018 ◽  
Vol 56 (3) ◽  
pp. 264 ◽  
Author(s):  
Mohammad Hossein Mohammadi ◽  
Mahnaz Khataar
Keyword(s):  
Numerical Model ◽  
Water Content ◽  
Soil Water ◽  
Water Uptake ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Weighting Function ◽  
Water Salinity ◽  
Irrigation Water Salinity ◽  
Evapotranspiration Rate

We developed a numerical model to predict soil salinity from knowledge of evapotranspiration rate, crop salt tolerance, irrigation water salinity, and soil hydraulic properties. Using the model, we introduced a new weighting function to express the limitation imposed by salinity on plant available water estimated by the integral water capacity concept. Lower and critical limits of soil water uptake by plants were also defined. We further analysed the sensitivity of model results to underlying parameters using characteristics given for corn, cowpea, and barley in the literature and two clay and sandy loam soils obtained from databases. Results showed that, between two irrigation events, soil salinity increased nonlinearly with decreasing soil water content especially when evapotranspiration and soil drainage rate were high. The salinity weighting function depended greatly on the plant sensitivity to salinity and irrigation water salinity. This research confirmed that both critical and lower limits (in terms of water content) of soil water uptake by plants increased with evapotranspiration rate and irrigation water salinity. Since the presented approach is based on a physical concept and well-known plant parameters, soil hydraulic characteristics, irrigation water salinity, and meteorological conditions, it may be useful in spatio-temporal modelling of soil water quality and quantity and prediction of crop yield.

Towards the consideration of soil-root resistances in root water uptake models with macroscopic representations of hydraulic root architecture

2021 ◽  
Author(s):  
Jan Vanderborght ◽  
Valentin Couvreur ◽  
Felicien Meunier ◽  
Andrea Schnepf ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Water Uptake ◽  
Root Distribution ◽  
Root Architecture ◽  
Soil Layer ◽  
Root Water Uptake ◽  
Hydraulic Architecture ◽  
Root Segments ◽  
Soil Volume

<p>Plant water uptake from soil is an important component of terrestrial water cycle with strong links to the carbon cycle and the land surface energy budget. To simulate the relation between soil water content, root distribution, and root water uptake, models should represent the hydraulics of the soil-root system and describe the flow from the soil towards root segments and within the 3D root system architecture according to hydraulic principles. We have recently demonstrated how macroscopic relations that describe the lumped water uptake by all root segments in a certain soil volume, e.g. in a thin horizontal soil layer in which soil water potentials are uniform, can be derived from the hydraulic properties of the 3D root architecture. The flow equations within the root system can be scaled up exactly and the total root water uptake from a soil volume depends on only two macroscopic characteristics of the root system: the root system conductance, K<sub>rs</sub>, and the uptake distribution from the soil when soil water potentials in the soil are uniform, <strong>SUF</strong>. When a simple root hydraulic architecture was assumed, these two characteristics were sufficient to describe root water uptake from profiles with a non-uniform water distribution. This simplification gave accurate results when root characteristics were calculated directly from the root hydraulic architecture. In a next step, we investigate how the resistance to flow in the soil surrounding the root can be considered in a macroscopic root water uptake model. We specifically investigate whether the macroscopic representation of the flow in the root architecture, which predicts an effective xylem water potential at a certain soil depth, can be coupled with a model that describes the transfer from the soil to the root using a simplified representation of the root distribution in a certain soil layer, i.e. assuming a uniform root distribution.</p>

scholarly journals Assessment of soil and soil-water salinity in Ben Tre province by electromagnetic technology

2020 ◽  
Vol 19 (4) ◽  
pp. 507-516
Author(s):  
Le Ngoc Thanh ◽  
Nguyen Quang Dung ◽  
Luu Hai Tung
Keyword(s):  
Electrical Conductivity ◽  
Soil Water ◽  
Ground Surface ◽  
Fold Increase ◽  
Water Salinity ◽  
Current Status ◽  
Soil Electrical Conductivity ◽  
Geostatistical Techniques ◽  
Data Point ◽  
Total Dissolved Solid

Assessment of soil and soil-water salinity is essential in agricultural production, therefore it is necessary to find out the non-costly, effective, rapid and reliable integrated methodology for this purpose. The paper presents the results of using the electromagnetic induction instrument EM31-MK2Ô in combination with collecting and analyzing soil and soil-water samples, and applying GIS and geostatistical techniques to assess the current status of soil and soil-water salinity in Ben Tre province. Apparent soil electrical conductivity ECa measured from ground surface to 6 m in depth increases from inland to the sea in northwest - southeast direction; ECa is closely related to topsoil salinity to 30 cm deep and to soil-water salinity at depth of 10–100 cm. Current status of soil and soil-water salinity in 2018 was assessed with a 4-fold increase in information, from 16 km2/data point to 4 km2/data point. Consequently four maps were established, consisting of electrical conductivity ECe and total solube salt TSS distributions of soil; electrical conductivity σw and total dissolved solid TDS distributions of soil-water.

scholarly journals Water Deficit Modulates the CO2 Fertilization Effect on Plant Gas Exchange and Leaf-Level Water Use Efficiency: A Meta-Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Li ◽  
Dagang Guo ◽  
Xiaodong Gao ◽  
Xining Zhao
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Future Climate Change ◽  
Leaf Level ◽  
Fertilization Effect ◽  
Use Efficiency ◽  
Stimulation Of

Elevated atmospheric CO2 concentrations ([eCO2]) and soil water deficits significantly influence gas exchange in plant leaves, affecting the carbon-water cycle in terrestrial ecosystems. However, it remains unclear how the soil water deficit modulates the plant CO2 fertilization effect, especially for gas exchange and leaf-level water use efficiency (WUE). Here, we synthesized a comprehensive dataset including 554 observations from 54 individual studies and quantified the responses for leaf gas exchange induced by e[CO2] under water deficit. Moreover, we investigated the contribution of plant net photosynthesis rate (Pn) and transpiration rates (Tr) toward WUE in water deficit conditions and e[CO2] using graphical vector analysis (GVA). In summary, e[CO2] significantly increased Pn and WUE by 11.9 and 29.3% under well-watered conditions, respectively, whereas the interaction of water deficit and e[CO2] slightly decreased Pn by 8.3%. Plants grown under light in an open environment were stimulated to a greater degree compared with plants grown under a lamp in a closed environment. Meanwhile, water deficit reduced Pn by 40.5 and 37.8%, while increasing WUE by 24.5 and 21.5% under ambient CO2 concentration (a[CO2]) and e[CO2], respectively. The e[CO2]-induced stimulation of WUE was attributed to the common effect of Pn and Tr, whereas a water deficit induced increase in WUE was linked to the decrease in Tr. These results suggested that water deficit lowered the stimulation of e[CO2] induced in plants. Therefore, fumigation conditions that closely mimic field conditions and multi-factorial experiments such as water availability are needed to predict the response of plants to future climate change.

scholarly journals GAS EXCHANGE, CHLOROPLAST PIGMENTS AND GROWTH OF PASSION FRUIT CULTIVATED WITH SALINE WATER AND POTASSIUM FERTILIZATION 1

2020 ◽  
Vol 33 (1) ◽  
pp. 184-194
Author(s):  
GEOVANI SOARES DE LIMA ◽  
COSMO GUSTAVO JACOME FERNANDES ◽  
LAURIANE ALMEIDA DOS ANJOS SOARES ◽  
HANS RAJ GHEYI ◽  
PEDRO DANTAS FERNANDES
Keyword(s):  
Gas Exchange ◽  
Saline Water ◽  
Block Design ◽  
Co2 Assimilation ◽  
Passion Fruit ◽  
Water Salinity ◽  
Chloroplast Pigments ◽  
Potassium Fertilization ◽  
Randomized Block Design ◽  
Fruit Plants

ABSTRACT The objective of this study was to evaluate the gas exchange, chloroplast pigments and growth of ‘BRS Rubi do Cerrado’ passion fruit as a function of irrigation with saline water and potassium fertilization in the seedling formation stage. The experiment was conducted under greenhouse conditions in the municipality of Pombal-PB, Brazil. A randomized block design was used in 5 x 2 factorial scheme, corresponding to five levels of water electrical conductivity - ECw (0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1) and two doses of potassium - KD (50 and 100% of the recommendation), with four replicates and two plants per plot. Water salinity from 0.3 dS m-1 reduced the stomatal opening, transpiration, CO2 assimilation and inhibited the growth of ‘BRS Rubi do Cerrado’ passion fruit plants, at 40 days after sowing. There was no CO2 restriction in the substomatal cavity of passion fruit plants grown under water salinity from 0.3 dS m-1. Potassium dose of 150 mg kg-1 of soil, corresponding to 100%, intensified the effect of salt stress on the assimilation rate and instantaneous carboxylation efficiency in 'BRS Rubi do Cerrado' passion fruit. There was interaction between water salinity levels and potassium doses for the chlorophyll a and b contents of 'BRS Rubi do Cerrado' passion fruit.

Daily inundation induced seasonal variation in the vertical distribution of soil water salinity in an estuarine mangrove forest under a tropical monsoon climate

2020 ◽  
Vol 35 (4) ◽  
pp. 638-649
Author(s):  
Akira Komiyama ◽  
Sasitorn Poungparn ◽  
Suthathip Umnouysin ◽  
Chadtip Rodtassana ◽  
Shogo Kato ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Soil Water ◽  
Mangrove Forest ◽  
Water Salinity ◽  
Monsoon Climate ◽  
Tropical Monsoon ◽  
The Vertical Distribution

The responses of stomata and leaf gas exchange to vapour pressure deficits and soil water content

Oecologia ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 356-362 ◽  
Author(s):  
T. Gollan ◽  
N. C. Turner ◽  
E. -D. Schulze
Keyword(s):  
Gas Exchange ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Vapour Pressure ◽  
Leaf Gas Exchange

Shoot Population Dynamics of Carex kobomugi on a Coastal Sand Dune in Relation to its Zonal Distribution

1998 ◽  
Vol 46 (1) ◽  
pp. 111 ◽  
Author(s):  
S.-I. Ishikawa ◽  
N. Kachi
Keyword(s):  
Population Dynamics ◽  
Soil Water ◽  
Growth Form ◽  
Sea Water ◽  
Injury Rate ◽  
Coastal Dunes ◽  
Imperata Cylindrica ◽  
Water Salinity ◽  
Zonal Distribution ◽  
Carex Kobomugi

Shoot population dynamics of Carex kobomugi Ohwi, a rhizomatous perennial sedge with a guerilla-type growth form, dominating on Japanese coastal dunes, were examined to detect factors generating the zonal distribution pattern of the plant species. Relative growth rate of shoot (RGRS) and number of branching shoots formed by a mother shoot in a year (NBr) were measured in three populations occurring at three different distances from the shoreline. In 1992, Carex kobomugi shoots at the most inland site (90 m from the shoreline), where Imperata cylindrica var. koenigii dominated and soil-water salinity is always low, showed the lowest RGRS (0.0172 g g-1 day-1 from April to June and 0.00079 g g-1 day-1 in July) and the smallest NBr (1.3 shoots shoot-1 year–1 averaged for 3 years). Shoots of the species at the most seaward site (40 m from the shoreline), where the soil-water salinity is always higher than that of more inland sites, showed the highest RGRS (0.0228 g g-1 day-1 from April to June and 0.0093 g g-1 day-1 in July) and the largest NBr (2.5 shoots-1). However, Carex kobomugi population at the 40 m site had a high fraction of injured shoots (46% of total shoots sampled), which were recorded as shoots without any greenish above-ground part, and high mortality (0.34) due to temporal flooding of sea water caused by storms. In the intermediate site (70 m from the shoreline), Carex kobomugi had intermediateRGRS and NBr with low injury rate. The NBr value, however, showed a decreasing trend over the 3 years of observation, suggesting deteriorating effects of intraspecific competition on population dynamics. In the spring of the fourth year, shoots of Carex kobomugi at 70 m and 90 m from the shoreline produced 1.2 to 2.0 times higher number of buds per shoot than the 3-year-averaged NBrs. This suggests that some fractions of the buds were terminated or became dormant through intra- and/or inter-specific competition. The sparse distribution of Carex kobomugi at the 90 m site may be dictated by its competitive inferiority to Imperata cylindrica which has a denser root system and an aggressive growth form of a phalanx type.

Variability in hydraulic architecture and gas exchange of common bean (Phaseolus vulgaris) cultivars under well-watered conditions: interactions with leaf size

1999 ◽  
Vol 26 (2) ◽  
pp. 115 ◽  
Author(s):  
Maurizio Mencuccini ◽  
Jonathan Comstock
Keyword(s):  
Gas Exchange ◽  
Exchange Rates ◽  
Common Bean ◽  
Water Loss ◽  
Leaf Size ◽  
Hydraulic Conductance ◽  
Hydraulic Architecture ◽  
Greenhouse Study ◽  
Whole Plant ◽  
Leaf Level

In a greenhouse study, 12 common bean cultivars from a wide geographical range were compared for their morphological, gas exchange and hydraulic architecture characters. Cultivars bred for cultivation in hot and dry regions had significantly smaller leaves and crowns, but higher stomatal conductances and transpiration rates per unit of leaf area. Short-term variability in gas exchange rates was confirmed using leaf carbon isotope discrimination. A literature survey showed that, although previously unnoticed, the strong inverse coupling between leaf size and gas exchange rates was present in three other studies using the same set of cultivars. Several measures of ‘leaf-specific hydraulic conductance’ (i.e. for the whole plant and for different parts of the xylem pathway) were also linearly related to rates of water loss, suggesting that the coupling between leaf size and gas exchange was mediated by a hydraulic mechanism. It is possible that breeding for high production in hot regions has exerted a selection pressure to increase leaf-level gas exchange rates and leaf cooling. The associated reductions in leaf size may be explained by the need to maintain equilibrium between whole-plant water loss and liquid-phase hydraulic conductance.

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