A Continuous Semi‐nonparametric Isotope‐Based Mixing Model for Multimodal Water Uptake Patterns

Ecohydrology, Journal Year: 2025, Volume and Issue: 18(1)

Published: Jan. 1, 2025

ABSTRACT Isotope mixing models have become increasingly prevalent in the partitioning of root water uptake. However, many fail to incorporate site physical information a physically meaningful manner, whereas others adopt discrete approaches segmenting soil profile rather than continuous that aptly treat as continuum properties and conditions. Here, we present novel ‘multimodal physically‐based uptake isotope estimation’ model (Multi‐PRIME). The utilizes flexible, multimodal probability density function conjunction with water‐stable isotopes additional information, combined process‐based linear framework. To evaluate approach, estimates from boreal forest Pinus banksiana trees were compared those PRIME MixSIAR approaches. yielded comparable results; however, because highly flexible nature its semi‐nonparametric function, Multi‐PRIME reduced bias uncertainty associated segmentation specification parametric functions initial parameter values model. Furthermore, provided superior ability describe patterns cases multiple potential source regions In addition, due nature, surpassed discrete, empirically‐based both accuracy certainty. These findings illustrate benefits adopting modelling framework semi‐nonparametric, thereby providing an improvement our confidently estimate apportionment.

Language: Английский

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Water usage of old-growth oak at elevated CO₂ in the FACE (Free-Air CO₂ Enrichment) of climate change

Biogeosciences, Journal Year: 2025, Volume and Issue: 22(6), P. 1557 - 1581

Published: March 25, 2025

Abstract. Predicting how increased atmospheric CO2 levels will affect water usage by whole, mature trees remains a challenge. The present study investigates diurnal (i.e. daylight) of oaks within an old-growth forest during experimental treatment season (April–October, inclusive). Over the years 2017–2021, inclusive (years 1–5 experiment), we collected individual tree data from 18 (Quercus robur L.) large-scale manipulative experiment at Birmingham Institute Forest Research (BIFoR) Free-Air Enrichment (FACE) temperate in central England, UK. Diurnal per day (TWU, L d−1) across leaf-on seasons was derived these data. Equal numbers were monitored each treatment: FACE infrastructure arrays (+150 µ mol mol−1) elevated (eCO2), control ambient (aCO2) arrays, and “ghost” (no-treatment, no-infrastructure) arrays. TWU linearly proportional to stem radius, Rb (∼ 3.1 d−1 mm−1; 274 mm ≤ 465 mm). also very good proxy for projected canopy area, Ac (m2), which 617 m2 m−1). Applying stem-to-canopy relation implied mean July ∼ 5 m−2 oak BIFoR forest. We normalised derive TWUn (L mm−1). report whole-season effects, differing year on year, alongside July-only results. In 2019 2021 seasons, after correction repeated measures, there 13 %–16 %, reduction eCO2 compared aCO2 TWUn, with marginal 4 % 2020, but model results not statistically significant. Control exhibited significant 27 increase ghost whole 2019, lesser, nonsignificant fixed effects 2020 2021. Several factors may have contributed: installation or operation infrastructure; array-specific differences soil moisture, slope, respiration; mix subdominant species present. Our showing per-tree savings under align sap flow other experiments greatly extend duration observations oak, elucidating seasonal patterns interannual differences. tree-centred viewpoint complements leaf-level ground-based measurements our understanding plant

Language: Английский

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TreeNet–The Biological Drought and Growth Indicator Network

Frontiers in Forests and Global Change, Journal Year: 2021, Volume and Issue: 4

Published: Nov. 4, 2021

The TreeNet research and monitoring network has been continuously collecting data from point dendrometers air soil microclimate using an automated system since 2011. goal of is to generate high temporal resolution datasets tree growth water dynamics for provide near real-time indicators forest performance drought stress a wide audience. This paper explains the key working steps installation sensors in field acquisition, transmission, processing, online visualization. Moreover, we discuss underlying premises convert dynamic stem size changes into relevant biological information. Every 10 min, radii about 420 trees 13 species at 61 sites Switzerland are measured electronically with micrometer precision, parallel environmental conditions above below ground. automatically transmitted, processed stored on central server. Automated processing (R-based functions) includes screening outliers, interpolation gaps, extraction radial deficit each tree. These long-term used scientific investigations as well calculate display daily trends levels based historical current data. collection over 100 million points forms basis identifying tree-, site- species-specific processes along gradients. one few networks capable tracking diurnal seasonal cycles physiology real-time, covering range temperate their respective conditions.

Language: Английский

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A process‐based water stable isotope mixing model for plant water sourcing

Ecohydrology, Journal Year: 2024, Volume and Issue: 17(1)

Published: Jan. 1, 2024

Abstract Stable isotopes of hydrogen and oxygen in water are common tools for investigating uptake apportionment, but many the existing methods rely on simple linear mixing approaches that do not mechanistically incorporate additional information about site physical properties conditions. Here, we develop a ‘physically based root isotope estimation’ model (PRIME) combines continuous parametric probability density function with data process‐based framework. To demonstrate application PRIME, patterns boreal forest Pinus banksiana trees were estimated four dates 2019. aid validation, estimates compared Bayesian framework, MixSIAR. The two provided similar results, due to its nature, PRIME superior resolution, certainty, parsimony. Although both models into their frameworks, does so mechanistic manner, thereby reflecting relevant hydrological processes more effectively than purely empirical approach taken by Furthermore, because uses describe predicted pattern, it allows users quantify essentially infinite through integration over desired depth ranges. These findings advantages utilizing continuous, parametric, estimate thus providing relatively yet powerful tool which plant sourcing.

Language: Английский

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Radiation, Air Temperature, and Soil Water Availability Drive Tree Water Deficit Across Temporal Scales in Canada's Western Boreal Forest

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(8)

Published: April 10, 2024

Abstract Changes are projected for the boreal biome with complex and variable effects on forest vegetation including drought‐induced tree mortality loss. With soil atmospheric conditions governing drought intensity, specific drivers of trees water stress can be difficult to disentangle across temporal scales. We used wavelet analysis causality detection identify potential environmental controls (evapotranspiration, moisture, rainfall, vapor pressure deficit, air temperature photosynthetically active radiation) daily deficit longer periods dehydration in black spruce tamarack. Daily was controlled by radiation, temperature, causing greater stand evapotranspiration. Prolonged (multi‐day) were regulated radiation moisture. provide empirical evidence that continued warming drying will cause short‐term increases tamarack transpiration, but reduced availability.

Language: Английский

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