Search results for "drought"

Spatio‐temporal patterns of tree growth as related to carbon isotope fractionation in European forests under changing climate

2019

Aim The aim was to decipher Europe‐wide spatio‐temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming. Location Europe and North Africa (30‒70° N, 10° W‒35° E). Time period 1901‒2003. Major taxa studied Temperate and Euro‐Siberian trees. Methods We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree‐ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic…

Water recycling in leaves of Lithops (Aizoaceae)

2016

Lithops plants consist of a pair of succulent leaves inserted on a short stem; each growing season young leaves develop in a cavity formed between the older pair. Young leaves can take up water from the older pair allowing the plant to maintain growth and leaf expansion even without external supply of water. Recycling water between vegetative organs is one of the possible adaptation strategies of plants under drought stress, but it had never been demonstrated experimentally in Lithops. The methodology used to verify the existence of water redistribution from old leaves to young leaves was fluorescence microscopy, using two dyes to follow the water pathway inside the plant: Sulforhodamine G …

Drought Stress Memory at the Plant Cycle Level: A Review

2021

International audience; Plants are sessile organisms whose survival depends on their strategy to cope with dynamic, stressful conditions. It is urgent to improve the ability of crops to adapt to recurrent stresses in order to alleviate the negative impacts on their productivity. Although our knowledge of plant adaptation to drought has been extensively enhanced during the last decades, recent studies have tackled plant responses to recurrent stresses. The present review synthesizes the major findings from studies addressing plant responses to multiple drought events, and demonstrates the ability of plants to memorize drought stress. Stress memory is described as a priming effect allowing a …

Persistence of submerged macrophytes in a drying world: Unravelling the timing and the environmental drivers to produce drought-resistant propagules

2018

Water status and gas exchange of pistachio trees under different irrigation levels

2017

The aim of this study was to investigate the physiological responses of pistachio trees to varying water supply in the attempt to identify reliable parameters to manage irrigation. Three different irrigation regimes were applied to 25-year-old pistachio trees of cultivar 'Bianca' on P. terebinthus rootstock. Midday stem water potential (ΨSWP), leaf relative water content (RWC), light-saturated net CO2assimilation (An), stomatal conductance (gs), and ambient conditions were monitored throughout the season, and light response curves of net photosynthesis were constructed. To reflect tree water status, trees were separated into three classes of ΨSWP, no deficit (ΨSWP> -1.5 MPa), mild defici…

A Cultivar-Sensitive Approach for the Continuous Monitoring of Olive (Olea europaea L.) Tree Water Status by Fruit and Leaf Sensing

2020

Sustainable irrigation is crucial to reduce water use and management costs in modern orchard systems. Continuous plant-based sensing is an innovative approach for the continuous monitoring of plant water status. Olive (Olea europaea L.) genotypes can respond to drought using different leaf and fruit physiological and morphological mechanisms. This study aimed to identify whether fruit and leaf water dynamics of two different olive cultivars were differently affected by water deficit and their response to changes of midday stem water potential (Ψstem), the most common indicator of plant water status. Plant water status indicators such as leaf stomatal conductance (gs) and Ψstem were measured…

Testing the potential significance of different scion/rootstock genotype combinations on the ecology of old cultivated olive trees in the southeast M…

2017

Background A previous multi-locus lineage (MLL) analysis of SSR-microsatellite data of old olive trees in the southeast Mediterranean area had shown the predominance of the Souri cultivar (MLL1) among grafted trees. The MLL analysis had also identified an MLL (MLL7) that was more common among rootstocks than other MLLs. We here present a comparison of the MLL combinations MLL1 (scion)/MLL7 (rootstock) and MLL1/MLL1 in order to investigate the possible influence of rootstock on scion phenotype. Results A linear regression analysis demonstrated that the abundance of MLL1/MLL7 trees decreases and of MLL1/MLL1 trees increases along a gradient of increasing aridity. Hypothesizing that grafting o…

Seed germination under osmotic stress across different wild populations of mountain rye (Secale strictum (C.Presl) C.Presl))

2020

The selection of resilient cultivars could help stem the losses in forage production due to a changing climate. Secale strictum is a wild grass with interesting potential as a forage crop. We studied the germination requirements of six wild S. strictum populations, representative of the whole species distribution range in Italy and occurring under different osmotic conditions (0 MPa, −0.8 MPa, −1.0 MPa, −1.2 MPa, −1.4 MPa and −1.6 MPa). Our aim was to find beneficial seed and germination traits for the possible use of this species as a crop. Different accessions of domesticated Secale cereale and ×Triticosecale were used as comparison. Some populations of S. strictum were drought tolerant a…

Persistence of remnant boreal plants in the Chiricahua Mountains, southern Arizona

2020

Abstract Boreal plants growing along the southern edge of their range on isolated mountains in a hot desert matrix live near the extreme of their physiological tolerance. Such plants are considered sensitive to small changes in climate. We coupled field observations (1974, 1993, 2019) about the abundance and vigor of small populations of ten remnant boreal plant species persisting in the uppermost elevations of spruce-fir forests of the Chiricahua Mountains, together with modeling of the species sensitivities to three stress factors associated with climatic change: warming, drought, and forest fire, in order to explore the persistence of frontier boreal plant species during climate change. …

Drought tolerance of three olive cultivars alternatively selected for rain fed or intensive cultivation

2016

Abstract Physiological drought response was evaluated for two olive cultivars commonly grown under rain fed conditions (‘Souri’ and ‘Picual’) and another selected for intensive, irrigated cultivation (‘Barnea’). ‘Souri’ is a traditional local Israeli cultivar, ‘Picual’ originated in Spain and ‘Barnea’ is a modern Israeli cultivar. Trees in pots were alternatively provided well irrigated conditions (100% FC, field capacity) or allowed to dry, first to 33% FC and then to 10% FC. Under conditions of greatest water availability, the ‘Barnea’ cultivar had the highest stomatal conductance and net photosynthesis, significantly higher than that found in ‘Souri’. Stomatal conductance and leaf water …