δ²H isotopic offsets in xylem water measurements under cryogenic vacuum distillation: Quantifying and correcting wood‐water hydrogen exchange influences

Ecohydrology, Journal Year: 2024, Volume and Issue: 17(3)

Published: March 16, 2024

Abstract Stable isotopes δ 18 O and 2 H are used to infer vegetation water sources. In some studies, significant xylem offsets from potential source waters have been observed. The appear be more prevalent with cryogenic vacuum distillation (CVD) of plant water. Hypothesized mechanisms for these include changes during uptake transport, methodological problems. We propose that a large portion the due hydrogen isotope exchange between non‐crystalline hydroxyl groups wood cellulose hemicellulose CVD. present method estimating hypothesized isotopic tissues water, which is result Rayleigh equilibrium fractionation. To estimate exchange, we use published properties North American tree species chemical relationships as function moisture content, CVD temperature extraction efficiency. A simple model captures range observations in studies non‐CVD methods were compared. evaluate model, compared observed (sw‐excess) values two field datasets (90°C, n = 364, 170°C, 43) estimated our model. found good agreement samples extracted at 90°C ( r 0.69) but not 170°C 0.20). offset may eliminated by increasing 229°C or adding standard sufficient raise content >150%. correction can also approximated applying theoretical calculation based on temperature,

Language: Английский

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Cryogenic vacuum distillation vs Cavitron methods in ecohydrology: Extraction protocol effects on plant water isotopic values

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 642, P. 131853 - 131853

Published: Aug. 18, 2024

Language: Английский

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Bark water uptake through lenticels increases stem hydration and contributes to stem swelling

Plant Cell & Environment, Journal Year: 2023, Volume and Issue: 47(1), P. 72 - 90

Published: Oct. 9, 2023

Foliar water uptake can recharge storage tissue and enable greater hydration than through access to soil alone; however, few studies have explored the role of bark in facilitating uptake. We investigated pathways dynamics (BWU) stems mangrove Avicennia marina. provide novel evidence that specific entry points control outer surface. Furthermore, using a fluorescent symplastic tracer dye we first lenticels on surface facilitate BWU, thus increasing stem content by up 3.7%. X-ray micro-computed tomography showed BWU was sufficient cause measurable swelling layers whole cross-sectional area 0.83 mm2 or 2.8%, implicating it as contributor diel patterns buffer xylem potential maintain living tissue.

Language: Английский

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Quantitative contribution of cryogenic vacuum extraction and radial water transport to xylem-source water deuterium offsets

Agricultural and Forest Meteorology, Journal Year: 2023, Volume and Issue: 345, P. 109837 - 109837

Published: Dec. 2, 2023

Language: Английский

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Functional Groups Mask Inter- and Intraspecific Variation in Water Use Strategies in a Seasonally Dry Tropical Forest

Frontiers in Water, Journal Year: 2022, Volume and Issue: 4

Published: July 7, 2022

Across the karst landscape of Quintana Roo, Mexico, plant access to nutrients and water appears limited by generally shallow soil. However, underlying this surface are heterogenous pockets in bedrock deeper, stable groundwater, suggesting potential for specialization species accessing soil resources. If differentially rock resources, divisions functional groups may also be expected. In study, caves provided an opportunity assess resource use strategies direct, species-specific root observations coupled with traditional above ground measurements. Utilizing isotopes from stems leaves (δ 18 O δ 13 C), we investigated efficiency trees during dry season uncover relationships between rooting habit, tree size, pre-determined based on leaf habit wood density. Functional group membership did not predict measured isotope ratios, indicating that were poor predictors use. We find evidence deep select larger individuals. Interestingly, as became larger, C increased a threshold but then declined, increasing vulnerability limitation increase consistent other seasonally tropical forests. Our work demonstrates that, although soils likely drive strong limitations, co-occurring ecosystems employ diverse acquisition strategies, important consequences community composition ecosystem function face environmental change.

Language: Английский

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Quantifying isotope parameters associated with carbonyl‐water oxygen exchange during sucrose translocation in tree phloem

New Phytologist, Journal Year: 2024, Volume and Issue: 242(3), P. 975 - 987

Published: March 5, 2024

Summary Stable oxygen isotope ratio of tree‐ring α‐cellulose (δ 18 O cel ) yields valuable information on many aspects tree–climate interactions. However, our current understanding the mechanistic controls δ is incomplete, with a knowledge gap existent regarding fractionation effect characterizing carbonyl‐water exchange during sucrose translocation from leaf to phloem. To address this insufficiency, we set up an experimental system integrating vapor O‐labeling feature manipulate leaf‐level isotopic signatures in tree saplings enclosed within whole‐canopy gas‐exchange cuvettes. We applied three different species determine their respective relationships between enrichment lamina (Δ l_suc and petiole phloem phl_suc under environmentally/physiologically stable conditions. Based determined Δ ‐Δ relationships, estimated that average, at least 25% atoms undergo water along leaf‐to‐phloem path biochemical factor accounting for such c. 34‰, markedly higher than conventionally assumed value 27‰. Our study represents significant step toward quantitative elucidation dynamics trees. This has important implications respect improving model its related applications paleoclimatic ecophysiological contexts.

Language: Английский

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Isotope Distribution Analysis in H₂¹⁸O Pulse‐Labeled Trees Frozen with Liquid Nitrogen

Physiologia Plantarum, Journal Year: 2024, Volume and Issue: 176(3)

Published: April 29, 2024

Abstract Tracer injection has long been recognized as a valuable tool for delineating tree hydraulics and assessing water transport pathways. Recently, isotope tracers have emerged innovative instruments investigating hydraulics, providing new insights into dynamics. Nevertheless, there is critical need further research to comprehensively grasp movement distribution within trees. A previously introduced technique analyzing the isotopic ratio of in wet tissues, offering millimeter‐scale resolution visualizing tracer movement, faces challenges due its underdeveloped sample preparation techniques. In this study, we an H 2 18 O S. gracilistyla samples, exclusively comprising indeterminate roots, stems, leaves, cultivated through hydroponics grown current year. Our objective was assess axial xylem. Additionally, devised novel method preparing frozen tissue enhancing repeatability success rate experiments. The results demonstrated that all samples exhibited average loss less than 0.6%. Isotopic analysis these unveiled consistent decline concentration with increasing height Salix specimens, three out five revealing significant gradient. findings affirm efficacy practicality combining labeling freezing, stabilization, Looking ahead, our methods are poised transcend woody plants, finding extensive applications plant physiology ecohydrology.

Language: Английский

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Snowmelt-mediated isotopic homogenization of shallow till soil

Hydrology and earth system sciences, Journal Year: 2024, Volume and Issue: 28(21), P. 4861 - 4881

Published: Nov. 8, 2024

Abstract. The hydrological cycle of sub-arctic areas is dominated by the snowmelt event. An understanding mechanisms that control water fluxes during high-volume infiltration events in till soils needed to assess how future changes timing and magnitude can affect soil storage dynamics. We conducted a tracer experiment which deuterated was used irrigate plot on forested hilltop Lapland, tracked different mobility monitored later modifies labelled storage. lysimeters destructive coring for sampling sampled groundwater. Large spatiotemporal variability between waters observed subsurface, while surface flow largely controlled fill-and-spill mechanism. Extensive saturation induced into roots nearby trees. found remained deeper layers over winter, but event gradually displaced all fully homogenized at soil–vegetation interface. conditions required full displacement old occur only with persistently high groundwater table. propose conceptual model where eventual replenishment three stages. First, unsaturated macropore initiated via microtopography directed towards second stage characterized rise through network, subsequent pore increased horizontal connectivity macropores. Shallow subsurface lateral develop more permeable shallow layers. In third stage, materializes long period table within soil, replenished enhanced matrix exchange network.

Language: Английский

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Do trees use stemflow water? A manipulative experiment on Singleleaf Piñon and Utah Juniper in Great Basin woodlands

Tree Physiology, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 16, 2024

Abstract It has been postulated that stemflow, precipitation flows from plant crowns down along branches and stems to soils, benefits plants generate it because increases plant-available soil water near the base of plant; however, little direct evidence supports this postulation. Were plants’ preferentially route their roots, woody with large canopies could benefit. For example, piñon juniper tree encroachment into sagebrush-steppe ecosystems be facilitated by intercepted routed roots as hypothetically reducing available for shrubs grasses. We tested whether Great Basin trees use benefit stemflow. In a drier-than-average wetter-than-average year, isotopically labeled was applied simulate Both species took up label signals peaking receding over 2 4 days. Despite uptake, no alleviation stress detected in drier year. The stemflow uptake resulted some wetter specifically piñons, which deeper profile than did junipers. Mixing model analyses suggested small fraction (approximately 0–2%), but an order-of-magnitude larger transpired those few days after addition. These findings represent novel demonstration rapid infiltrates rhizosphere, they also prompt questions about remaining stemflow’s fate why so minor.

Language: Английский

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Examining the complementarity in belowground water use between different varieties and ages of Arabica coffee plants and dominant shade tree species in an organic agroecosystem

Agricultural Water Management, Journal Year: 2024, Volume and Issue: 307, P. 109248 - 109248

Published: Dec. 18, 2024

Language: Английский

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