Bedrock vadose zone storage dynamics under extreme drought: consequences for plant water availability, recharge, and runoff

Recently, the signs of extreme droughts, which were thought of as exceptional and unlikely, are being detected worldwide. It is necessary to prepare countermeasures against extreme droughts; however, current definitions of extreme drought are just used as only one or two indicators to represent the status or severity of a drought. More representative drought factors, which can show the status and severity that are relevant to extreme drought, need to be considered depending on the characteristics of the drought and comprehensive evaluation of various indices. Therefore, this study attempted to quantitatively define regional extreme droughts using more acceptable factors. The methodology comprises five factors that are indicative of extreme drought. The five factors are (1) duration (days), (2) number of consecutive years (years), (3) water availability, (4) return period, and (5) regional experience. The results were analyzed by applying the procedure to droughts that took place in 2014–2015 in South Korea. The results showed that the applied historical event did not enter the status of extreme drought, which is proposed in this study; however, the proposed methodology is applicable because it uses acceptable and reasonable factors to judge extreme drought, but it can also take into account the past regional experience of extreme drought.

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Crown condition, water availability, insect damage and landscape features: are they important to the Chilean tree Nothofagus glauca (Nothofagaceae) in the context of climate change?

Australian Journal of Botany ◽

10.1071/bt13015 ◽

2013 ◽

Vol 61 (5) ◽

pp. 394 ◽

Cited By ~ 2

Author(s):

Scott H. Altmann

Keyword(s):

Climate Change ◽

Water Availability ◽

Leaf Damage ◽

Insect Damage ◽

Plant Water ◽

Vegetative Cover ◽

Crown Condition ◽

Plant Vigour ◽

Landscape Features ◽

The Impact

An understanding of the impact that climate change will have on dominant plant species is important given the central role of these species in ecosystem functioning. Southern beech (Nothofagus Blume) is a central genus in the forests of the southern cone of South America, with Nothofagus glauca (Phil.) Krasser a dominant, at-risk tree inhabiting the drought-prone region of central Chile. The present study explored the relationships among several environmental variables that may be critical to understanding the impact of climate change on N. glauca, most importantly crown condition, plant water availability, insect leaf damage and landscape features. Furthermore, the study examined whether these variables differed between individuals from drier or wetter stands distributed within a north–south geographic area. Multiple regression modelling detected important relationships for the dependent variable crown condition with branch midday water potential, N. glauca diameter at breast height and vegetative cover, as well as with landscape variables in interaction with different plant vigour and water availability measures. Negative correlations between insect damage and plant water availability measures were observed at two field sites. Overall, crown condition and water availability were higher, and insect damage was lower, in wetter stands. The results of the present study have important negative implications for the species in terms of climate change and can be applied to future investigations.

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Influence of the root endophytePiriformospora indicaon the plant water relations, gas exchange and growth ofChenopodium quinoaat limited water availability

Journal of Agronomy and Crop Science ◽

10.1111/jac.12199 ◽

2017 ◽

Vol 203 (5) ◽

pp. 373-384 ◽

Cited By ~ 11

Author(s):

S. Hussin ◽

W. Khalifa ◽

N. Geissler ◽

H.-W. Koyro

Keyword(s):

Gas Exchange ◽

Water Relations ◽

Water Availability ◽

Plant Water Relations ◽

Plant Water

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When Green Infrastructure Turns Grey: Plant Water Stress as a Consequence of Overdesign in a Tree Trench System

Water ◽

10.3390/w12020573 ◽

2020 ◽

Vol 12 (2) ◽

pp. 573

Author(s):

Min-cheng Tu ◽

Joshua Caplan ◽

Sasha Eisenman ◽

Bridget Wadzuk

Keyword(s):

Water Stress ◽

Water Availability ◽

Green Infrastructure ◽

Hydraulic Properties ◽

Physiological Stress ◽

Plant Stress ◽

Water Source ◽

Plant Water ◽

Performance Loss ◽

Soil Media

Green infrastructure (GI) systems are often overdesigned. This may be a byproduct of static sizing (e.g., accounting for a design storm’s runoff volume but not exfiltration rates) or may be deliberate (e.g., buffering against performance loss through time). In tree trenches and other GI systems that require stormwater to accumulate in an infiltration bed before it contacts the planting medium, overdesign could reduce plant water availability significantly. This study investigated the hydrological dynamics and water relations of an overdesigned tree trench system and identified factors contributing to, compounding, and mitigating the risk of plant stress. Water in the infiltration bed reached soil pits only once in three years, with that event occurring during a hydrant release. Moreover, minimal water was retained in soil pits during the event due to the hydraulic properties of the soil media. Through a growing season, one of the two tree types frequently experienced water stress, while the other did so only rarely. These contrasting responses can likely be attributed to roots being largely confined to the soil pits vs. reaching a deeper water source, respectively. Results of this study demonstrate that, in systems where soil pits are embedded in infiltration beds, overdesign can raise the storm size required for water to reach the soil media, reducing plant water availability between storms, and ultimately inducing physiological stress.

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Assessing the large-scale plant–water relations in the humid, subtropical Pearl River basin of China

Hydrology and Earth System Sciences ◽

10.5194/hess-25-4741-2021 ◽

2021 ◽

Vol 25 (9) ◽

pp. 4741-4758

Author(s):

Hailong Wang ◽

Kai Duan ◽

Bingjun Liu ◽

Xiaohong Chen

Keyword(s):

River Basin ◽

Water Relations ◽

Water Availability ◽

Large Scale ◽

Water Storage ◽

Pearl River ◽

Plant Water Relations ◽

Plant Water ◽

Pearl River Basin ◽

Vegetation Greenness

Abstract. Vegetation interacts closely with water resources. Conventional field studies of plant–water relations are fundamental for understanding the mechanisms of how plants alter and adapt to environmental changes, while large-scale studies can be more practical for regional land use and water management towards mitigating climate change impacts. In this study, we investigated the changes in the total water storage (TWS), aridity index (AI) and vegetation greenness, productivity, and their interactions in the Pearl River basin since April 2002. Results show an overall increasing trend of vegetation greenness and productivity, especially in the middle reaches where TWS also increased. This region dominated by croplands was identified as the hot spot for changes and interactions between water and vegetation in the basin. Vegetation was more strongly affected by TWS than precipitation (P) at both the annual and monthly scales. Further examination showed that the influence of TWS on vegetation in dry years was stronger than wet years, while the impact of P was stronger in wet years than dry years; moreover, vegetation productivity responded slower but stronger to atmospheric dryness in dry years than wet years. The lag effects resulted in nonlinearity between water and vegetation dynamics. This study implies that vegetation in the basin uses rainwater prior to water storage until the soil becomes dry, and their dynamics indicate that vegetation development is subject to water availability, and that vegetation is not dominant in reducing water availability.

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Soil Water Release Curves : Indicator to Suit Sustainable Cropping Scheme under Sloppy Rain-Fed Climatic Conditions of Pothowar Plateau of Punjab-Pakistan

AGRITROPICA Journal of Agricultural Sciences ◽

10.31186/agritropica.1.1.9-24 ◽

2018 ◽

Vol 1 (1) ◽

pp. 9-24

Author(s):

Rehmat Ullah ◽

Shehzada Munawar Mehdi ◽

Khalid Saif Ullah Khan ◽

Aftab Ahmed Sheikh ◽

Sigit Mujiharjo ◽

...

Keyword(s):

Soil Water ◽

Water Availability ◽

Management Practices ◽

Climatic Conditions ◽

Cropping Pattern ◽

Plant Water ◽

Water Release ◽

Drought Period ◽

Cropping Patterns ◽

Release Curve

In arid environment, limitations of crop productivity could be improved by soil management practices like soil conservation measures, tillage and reducing slopes through terracing on different cropping patterns. These patterns include area as Wheat-Maize (WMCP) and Wheat-Fodder (WFCP) in Kahuta (high rainfall climatic area), Wheat-Millet-Fallow (WMFCP) and Wheat- Millet-Lentil (WMLCP) in Khairimurat (medium rainfall climatic area) and Wheat-Fallow (WFCP) and Fallow-Groundnut (FGCP) in Pindi Gheb (low rainfall climatic area). In areas that have more crop water requirements the yield of these crops has been affected when the drought prevails. Our results evidenced that more average soil water content (ASWC) was available in high to medium height terraces in WMCP and low to medium in WFCP of Kahuta area. ASWC remained more in high to medium height terraces under all cropping pattern of Khairimurat during September. ASWC remained more in low to medium height terraces under all cropping pattern of Pindi Gheb during September and December. Equidistantly, soil water release curve also indicated that medium rainfall sites had more plant water availability as compared to high and low rainfall sites. Yield relationship to plant water availability revealed significance for intrusion of modified cropping patterns rather than existing cropping patterns on sustained basis. Finally, our study suggests that cropping patterns of high and low rainfall areas should adjusted by growing low water requirement crops in summer seasons to cope the drought period for the sustainability of agriculture under rainfed climatic conditions. Keywords : cropping patterns, Pothowar Plateau, soil water contents, soil water release curve, sloppy lands

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