scholarly journals The influence of drought on the water uptake by Scots pines (Pinus sylvestris L.) at different positions in the tree stand

2015 ◽  
Vol 76 (4) ◽  
pp. 370-376
Author(s):  
Andrzej Boczoń ◽  
Michał Wróbel
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Thermal Dissipation ◽  
Negative Effects ◽  
Drought Period ◽  
Water Tree ◽  
Pine Trees ◽  
Soil Moisture Availability ◽  
The Individual ◽  
Individual Trees

Abstract Periodically occurring drought is typical for the climate of Poland. In habitats supplied exclusively with rain water, tree stands are frequently exposed to the negative effects of water deficit in the soil. The aim of this study was to examine the water uptake and consumption of two individual Scots pine trees under drought conditions. The trees were located at different positions within the stand and at the time of study were over 150 years old. Soil moisture, availability of soil water and the quantity of water uptake by the individual trees were examined by measuring the water velocity inside the trunks (Thermal Dissipation Probe method). Two periods of intense drought occurred in the summer 2006 only a few days apart. Before the drought, pine No. 1 (dominant) took up 66.7 dm3 water per day and pine No. 2 (co-dominant) took up 52.3 dm3 per day. The observed responses of the examined pines to the first period of drought were similar: the low soil water content resulted in a suppression of water uptake in both trees. After the end of the drought period however, the recovery responses of the two trees were different. Pine No. 1 resumed water uptake at values similar to those before the drought. Pine No. 2 on the other hand did not resume water uptake. We conclude that in case of this second tree the vegetative season possibly ended already at the end of June.

Modeling of plant water uptake in two distinct forest stands using whole-plant capacitance approach

2021 ◽  
Author(s):  
Veronika Skalova ◽  
Michal Dohnal ◽  
Jana Votrubova ◽  
Tomas Vogel ◽  
Miroslav Tesar
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Sap Flow ◽  
Meteorological Data ◽  
Water Pressure ◽  
Thermal Dissipation ◽  
Richards Equation ◽  
Soil Drought ◽  
Flow Measurements ◽  
Whole Plant

<p>Soil-plant-atmosphere interactions are studied to improve the estimation of actual transpiration – the key part of the catchment water balance. The one-dimensional soil water flow model S1D, involving vertically distributed macroscopic root water uptake and whole-plant hydraulic capacitance, was used. The model is based on the numerical solution of Richards' equation coupled with a transient transpiration stream algorithm.</p><p>The study focuses on the catchment Liz located in the Bohemian Forest, Czech Republic. The catchment is covered with Norway spruce (Picea abies) and European beech (Fagus sylvatica). In 2020, sap flow measurements by thermal dissipation probes were conducted at both forest environments. Soil water pressure head, soil water content, and soil temperature data, as well as complete meteorological data from the nearby meteorological station, were also available for the whole period of interest.</p><p>The registered sap flow and simulated transpiration fluxes are compared with a particular attention to the different behavior of isohydric (spruce) and anisohydric (beech) trees. The model reasonably well reproduces the plant responses caused by both the high midday potential transpiration demand and the occasional soil drought.</p><p>The research is supported by the Czech Science Foundation Project No. 20-00788S.</p>

scholarly journals Drought Primarily Reduces Canopy Transpiration of Exposed Beech Trees and Decreases the Share of Water Uptake from Deeper Soil Layers

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 537 ◽  
Author(s):  
Dietmar Lüttschwager ◽  
Hubert Jochheim
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Water Budget ◽  
Xylem Sap ◽  
Forest Stand ◽  
Thermal Dissipation ◽  
Distribution Model ◽  
Soil Layers ◽  
Canopy Transpiration ◽  
Beech Stand

Research Highlights: During drought, reduced soil water availability and increased vapor pressure deficit diminished transpiration in a mature beech stand (Fagus sylvatica L.). Dominant trees were more affected than suppressed trees. The share of soil water uptake from deeper layers decreased. The ability of individual trees in the forest stand to save water during drought was apparently dependent on their social status. This would be relevant for forest management. Objectives: We investigated which basal area classes of trees contribute more or less to total transpiration under wet and dry conditions, and from which soil layers they took up water. We hypothesized that dominant trees have a better adaptability to drought and diminish transpiration more than suppressed trees. Methods: The water budget of the forest stand was continuously monitored throughout the entire observation period. Xylem sap flux measurements using thermal dissipation probes were performed during the vegetation period at different depths in the trunks of ten representative trees. A radial distribution model of the sap flow density pattern was used to compute whole-tree and stand transpiration. Water budget was simulated using a physiology-based model. Results: During drought, the fraction of suppressed trees to whole-canopy transpiration of the forest stand increased and the share of soil water uptake from deeper layers decreased. Conclusions: The behavior of dominant trees under drought conditions could be interpreted as a water-conserving strategy. Thinning by removing suppressed trees should be employed to stabilize forests.

Where does the water come from? Variations in soil water uptake depth in a beech forest during the 2018 drought

2020 ◽  
Author(s):  
Arthur Geßler ◽  
Lukas Bächli ◽  
Kerstin Treydtre ◽  
Matthias Saurer ◽  
Matthias Häni ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Supply ◽  
Soil Water ◽  
Water Uptake ◽  
In Situ Monitoring ◽  
Drought Period ◽  
Rainfall Events ◽  
Extreme Precipitation Events ◽  
Shallow Soil

<p>Water uptake under variable soil water supply is highly critical for the functioning of trees and the services provided by forests. Current climate projections predict an increasing variability of precipitation and thus a higher frequency of droughts alternating with extreme precipitation events. Reduced water availability is the most critical driver for tree mortality and impairment of trees’ functions. Under variable water supply, both the ability of a plant species to utilize remaining water under drought and to immediately capitalize on soil rewetting from subsequent rainfall events will be crucial for its survival and competitiveness. High uncertainty still exists regarding the ecohydrological belowground interactions at the soil–root interface on short to seasonal time scales.</p><p>To overcome previous limitations, we carried out high-resolution <em>in situ</em> observations of δ<sup>18</sup>O in soil and xylem water to track the water uptake of beech trees based on the approaches of Volkmann et al. (2016a & b) in the hot dry summer 2018. We set up a laser isotope system to continuously probe the δ<sup>18</sup>O signature in the water vapor in equilibrium with the soil water at different soil depths and with the xylem of beech trees in a forest in Switzerland and applied a Bayesian isotope mixing model (BIMM) to resolve the origin of the water taken up. Moreover, we installed xylem flow sensors, dendrometers and soil moisture sensors in the trees.</p><p>Mid of June the drought period started with extended phases of high temperature and only infrequent precipitation. At the same time, soil water content sharply decreased, especially in the upper soil layers and transpiration as well as radial growth started to decline, and this pattern became more pronounced until the end of August. In the soil water, strong <sup>18</sup>O enrichment in the upper 5 cm and slighter enrichment in 15 cm developed during this period. The BIMM results indicated that tree xylem water was made up by > 80% of shallow soil water (0-15 cm) at the onset of the drought and that this contribution continuously dropped to < 20% by the end of August, when deeper soil water and groundwater became more important. End of August, intensive rainfall events along with decreasing temperatures terminated the drought period when shallow soil water pools became partially replenished, and transpiration increased again. Within days, the contribution of shallow soil water to tree xylem water increased and reached a share of > 70% a couple of weeks after the end of the drought.  With the<em> in situ</em> method applied here, real-time information of the plasticity of soil water use becomes available and we can l trace the effect of drought and drought release on root activity of trees in different soil depths.</p><p> </p><p><strong>Volkmann THM, Haberer K, Gessler A, Weiler M. 2016a.</strong>High-resolution isotope measurements resolve rapid ecohydrological dynamics at the soil–plant interface. The New phytologist<strong>210</strong>: 839-849.</p><p><strong>Volkmann THM, Kühnhammer K, Herbstritt B, Gessler A, Weiler M. 2016b.</strong>A method for in situ monitoring of the isotope composition of tree xylem water using laser spectroscopy. Plant, Cell and Environment<strong>9</strong>: 2055–2063.</p>

Water uptake and redistribution during drought in a semiarid shrub species

2014 ◽  
Vol 41 (8) ◽  
pp. 812 ◽  
Author(s):  
Iván Prieto ◽  
Francisco I. Pugnaire ◽  
Ronald J. Ryel
Keyword(s):  
Shallow Water ◽  
Soil Water ◽  
Water Use ◽  
Water Uptake ◽  
Water Dynamics ◽  
Rain Event ◽  
Plant Water ◽  
Deep Soil ◽  
Drought Period ◽  
Plant Water Use

In arid systems, most plant mortality occurs during long drought periods when water is not available for plant uptake. In these systems, plants often benefit from scarce rain events occurring during drought but some of the mechanisms underlying this water use remain unknown. In this context, plant water use and redistribution after a large rain event could be a mechanism that allows deep-rooted shrubs to conservatively use water during drought. We tested this hypothesis by comparing soil and plant water dynamics in Artemisia tridentata ssp. vaseyana (Rydb.) Beetle shrubs that either received a rain event (20 mm) or received no water. Soil water content (SWC) increased in shallow layers after the event and increased in deep soil layers through hydraulic redistribution (HR). Our results show that Artemisia shrubs effectively redistributed the water pulse downward recharging deep soil water pools that allowed greater plant water use throughout the subsequent drought period, which ameliorated plant water potentials. Shrubs used shallow water pools when available and then gradually shifted to deep-water pools when shallow water was being used up. Both HR recharge and the shift to shallow soil water use helped conserve deep soil water pools. Summer water uptake in Artemisia not only improved plant water relations but also increased deep soil water availability during drought.

Grünbrücke Loterbuck A 4.2.9: Eine Erfolgskontrolle nach drei Jahren | Fauna Overbridge Loterbuck A 4.2.9: Success Control after a Period of Three Years

2000 ◽  
Vol 151 (8) ◽  
pp. 290-297
Author(s):  
Stephan Hatt
Keyword(s):  
Local People ◽  
Traffic Network ◽  
Negative Effects ◽  
The Individual

The expansion of the traffic network, in particular the construction of highways, has continuously diminished and divided into small sections the habitat of wild-living animals during the last decades. However, these negative effects can be minimised if suitable measures with regard to line-conduction and construction are taken against. One of these possibilities are the sown-down overbridges. It is essential that these constructions are planned and built in order to meet the requirements of their future users – the various wild-living animals. This study investigates the success of one of these sown-down overbridges. It is this the Loterbuck-overbridge on the A 4.2.9 near Henggart in the canton of Zurich, Switzerland. The focus of this investigation was to find out which species of wild-living animals use the bridge and how much it is frequented. Local people and specialists of the region were interviewed and tracks were picked up on site. Taking into consideration five criteria (species of wild-living animals, positioning and number of overbridges nearby, dimensioning and design of the individual overbridges), the interviews and tracks were assessed. The Loterbuck-overbridge is used by all larger wild-living animals of the region. Especially the browsing and rubbing tracks of deer show that the overbridge has been accepted not only as sown-down overbridge but also as habitat.

scholarly journals Optimal Nitrogen Fertilization to Reach the Maximum Grain and Stover Yields of Maize (Zea mays L.): Tendency Modeling

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1354
Author(s):  
Sergio E. Medina-Cuéllar ◽  
Deli N. Tirado-González ◽  
Marcos Portillo-Vázquez ◽  
Sergio Orozco-Cirilo ◽  
Marco A. López-Santiago ◽  
...  
Keyword(s):  
Nitrogen Fertilization ◽  
Zea Mays L ◽  
N Fertilization ◽  
Human Consumption ◽  
Alluvial Soils ◽  
Grain Production ◽  
Negative Effects ◽  
Maize Stover ◽  
The Individual ◽  
Quadratic Models

Utilization of maize stover to the production of meat and milk and saving the grains for human consumption would be one strategy for the optimal usage of resources. Variance and tendency analyses were applied to find the optimal nitrogen (N) fertilization dose (0, 100, 145, 190, 240, and 290 kg/ha) for forage (F), stover (S), cob (C), and grain (G) yields, as well as the optimal grain-to-forage, cob-to-forage, and cob-to-stover ratios (G:F, C:F, and C:S, respectively). The study was performed in central Mexico (20.691389° N and −101.259722° W, 1740 m a.m.s.l.; Cwa (Köppen), 699 mm annual precipitation; alluvial soils). N-190 and N-240 improved the individual yields and ratios the most. Linear and quadratic models for CDM, GDM, and G:F ratio had coefficients of determination (R2) of 0.20–0.46 (p < 0.03). Cubic showed R2 = 0.30–0.72 (p < 0.02), and the best models were for CDM, GDM, and the G:F, C:F, and C:S DM ratios (R2 = 0.60–0.72; p < 0.0002). Neither SHB nor SDM negatively correlated with CDM or GDM (r = 0.23–0.48; p < 0.0001). Excess of N had negative effects on forage, stover, cobs, and grains yields, but optimal N fertilization increased the proportion of the G:F, C:F, and C:S ratios, as well as the SHB and SDM yields, without negative effects on grain production.

scholarly journals Individual behavioural traits not social context affects learning about novel objects in archerfish

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Nick A. R. Jones ◽  
Helen C. Spence-Jones ◽  
Mike Webster ◽  
Luke Rendell
Keyword(s):  
Social Context ◽  
Social Environment ◽  
Social Contexts ◽  
Negative Effects ◽  
Behavioural Phenotype ◽  
Social Species ◽  
The Social ◽  
Social Animals ◽  
Novel Objects ◽  
The Individual

Abstract Learning can enable rapid behavioural responses to changing conditions but can depend on the social context and behavioural phenotype of the individual. Learning rates have been linked to consistent individual differences in behavioural traits, especially in situations which require engaging with novelty, but the social environment can also play an important role. The presence of others can modulate the effects of individual behavioural traits and afford access to social information that can reduce the need for ‘risky’ asocial learning. Most studies of social effects on learning are focused on more social species; however, such factors can be important even for less-social animals, including non-grouping or facultatively social species which may still derive benefit from social conditions. Using archerfish, Toxotes chatareus, which exhibit high levels of intra-specific competition and do not show a strong preference for grouping, we explored the effect of social contexts on learning. Individually housed fish were assayed in an ‘open-field’ test and then trained to criterion in a task where fish learnt to shoot a novel cue for a food reward—with a conspecific neighbour visible either during training, outside of training or never (full, partial or no visible presence). Time to learn to shoot the novel cue differed across individuals but not across social context. This suggests that social context does not have a strong effect on learning in this non-obligatory social species; instead, it further highlights the importance that inter-individual variation in behavioural traits can have on learning. Significance statement Some individuals learn faster than others. Many factors can affect an animal’s learning rate—for example, its behavioural phenotype may make it more or less likely to engage with novel objects. The social environment can play a big role too—affecting learning directly and modifying the effects of an individual’s traits. Effects of social context on learning mostly come from highly social species, but recent research has focused on less-social animals. Archerfish display high intra-specific competition, and our study suggests that social context has no strong effect on their learning to shoot novel objects for rewards. Our results may have some relevance for social enrichment and welfare of this increasingly studied species, suggesting there are no negative effects of short- to medium-term isolation of this species—at least with regards to behavioural performance and learning tasks.

scholarly journals Analysis of Soil Water Response to Grass Transpiration

2013 ◽  
Vol 1 (No. 3) ◽  
pp. 85-98
Author(s):  
Dohnal Michal ◽  
Dušek Jaromír ◽  
Vogel Tomáš ◽  
Herza Jiří
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Preferential Flow ◽  
Water Movement ◽  
Control Volume ◽  
Water Pressure ◽  
Lower Boundary ◽  
Root Water Uptake ◽  
Water Dynamics ◽  
Soil Water Dynamics

This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation. The lysimeter system provides a well defined control volume with boundary fluxes measured and soil water pressure continuously monitored. The evapotranspiration intensity is estimated by the Penman-Monteith method and compared with the measured lysimeter soil water loss and the simulated root water uptake. Variably saturated flow of water in the lysimeter is simulated using one-dimensional dual-permeability model based on the numerical solution of the Richards&rsquo; equation. The availability of water for the root water uptake is determined by the evaluation of the plant water stress function, integrated in the soil water flow model. Different lower boundary conditions are tested to compare the soil water dynamics inside and outside the lysimeter. Special attention is paid to the possible influence of the preferential flow effects on the lysimeter soil water balance. The adopted modelling approach provides a useful and flexible framework for numerical analysis of soil water dynamics in response to the plant transpiration.

scholarly journals Modelling the Impact on Root Water Uptake and Solute Return Flow of Different Drip Irrigation Regimes with Brackish Water

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 425 ◽  
Author(s):  
Fairouz Slama ◽  
Nessrine Zemni ◽  
Fethi Bouksila ◽  
Roberto De Mascellis ◽  
Rachida Bouhlila
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Uptake ◽  
Brackish Water ◽  
Deficit Irrigation ◽  
Root Zone ◽  
Root Water Uptake ◽  
Return Flows ◽  
Semi Arid

Water scarcity and quality degradation represent real threats to economic, social, and environmental development of arid and semi-arid regions. Drip irrigation associated to Deficit Irrigation (DI) has been investigated as a water saving technique. Yet its environmental impacts on soil and groundwater need to be gone into in depth especially when using brackish irrigation water. Soil water content and salinity were monitored in a fully drip irrigated potato plot with brackish water (4.45 dSm−1) in semi-arid Tunisia. The HYDRUS-1D model was used to investigate the effects of different irrigation regimes (deficit irrigation (T1R, 70% ETc), full irrigation (T2R, 100% ETc), and farmer’s schedule (T3R, 237% ETc) on root water uptake, root zone salinity, and solute return flows to groundwater. The simulated values of soil water content (θ) and electrical conductivity of soil solution (ECsw) were in good agreement with the observation values, as indicated by mean RMSE values (≤0.008 m3·m−3, and ≤0.28 dSm−1 for soil water content and ECsw respectively). The results of the different simulation treatments showed that relative yield accounted for 54%, 70%, and 85.5% of the potential maximal value when both water and solute stress were considered for deficit, full. and farmer’s irrigation, respectively. Root zone salinity was the lowest and root water uptake was the same with and without solute stress for the treatment corresponding to the farmer’s irrigation schedule (273% ETc). Solute return flows reaching the groundwater were the highest for T3R after two subsequent rainfall seasons. Beyond the water efficiency of DI with brackish water, long term studies need to focus on its impact on soil and groundwater salinization risks under changing climate conditions.

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.

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