Responses of nighttime sap flow to atmospheric and soil dryness and its potential roles for shrubs on the Loess Plateau of China

Fang, Weiwei; Lü, Nan; Zhang, Yu; Jiao, Lixin; Fu, Bojie

doi:10.1093/jpe/rtx042

Cited by 21 publications

(22 citation statements)

References 55 publications

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“…Furthermore, plant water storage enables the simulation of nocturnal plant water recharge. Nocturnal water recharge has ecophysiological significance to plants, including relieving xylem hydraulic stress and delivering nutrients (Daley & Phillips 2006;Fang et al, 2018;McDonald et al, 2002;Scholz et al, 2007;Snyder et al, 2003). Our tree-level simulations show that the nighttime recharge of red maple and red oak accounts for nearly 50% of the daily total soil-to-root water flux (Figure 8).…”

Section: Discussionmentioning

confidence: 84%

Representation of Plant Hydraulics in the Noah‐MP Land Surface Model: Model Development and Multiscale Evaluation

Yang

Matheny

et al. 2021

J Adv Model Earth Syst

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Plants are expected to face increasing water stress under future climate change. Most land surface models, including Noah-MP, employ an idealized "big-leaf" concept to regulate water and carbon fluxes in response to soil moisture stress through empirical soil hydraulics schemes (SHSs). However, such schemes have been shown to cause significant uncertainties in carbon and water simulations. In this paper, we present a novel plant hydraulics scheme (PHS) for Noah-MP (hereafter, Noah-MP-PHS), which employs a big-tree rather than big-leaf concept, wherein the whole-plant hydraulic strategy is considered, including root-level soil water acquisition, stem-level hydraulic conductance and capacitance, and leaflevel anisohydricity and hydraulic capacitance. Evaluated against plot-level observations from a mature, mixed hardwood forest at the University of Michigan Biological Station and compared with the default Noah-MP, Noah-MP-PHS better represents plant water stress and improves water and carbon simulations, especially during periods of dry soil conditions. Noah-MP-PHS also improves the asymmetrical diel simulation of gross primary production under low soil moisture conditions. Noah-MP-PHS is able to reproduce different patterns of transpiration, stem water storage and root water uptake during a 2-week dry-down period for two species with contrasting plant hydraulic behaviors, i.e., the "cavitation riskaverse" red maple and the "cavitation risk-prone" red oak. Sensitivity experiments with plant hydraulic capacitance show that the stem water storage enables nocturnal plant water recharge, affects plant water use efficiency, and provides an important buffer to relieve xylem hydraulic stress during dry soil conditions.Plain Language Summary Plants regulate transpiration dynamically through the stomatal aperture, which, in many cases, is governed by plant water status and hydraulic properties. Plant hydraulics describes the mechanics of water movement through plant vascular systems, which is the culmination of emergent phenotypical hydraulic functional traits at the leaf, stem, and root levels. Such physiological mechanisms are excluded in most land surface models, which typically represent plant water stress through empirical soil hydraulics schemes (SHSs) based on either soil water content or soil water potential. In this study, we present a novel plant hydraulics scheme (PHS) to represent plant water stress and the regulation of stomatal conductance for use in the Noah-MP land surface model. Our results show Noah-MP-PHS performs better in its water and carbon simulations than the default Noah-MP with traditional SHSs, especially under dry soil conditions. Noah-MP-PHS also successfully captures the different plant hydraulic behaviors between the "cavitation risk-averse" red maple and the "cavitation risk-prone" red oak. Sensitivity experiments also highlight the vital role played by plant water storage in water and carbon simulations in terms of buffering xylem hydraulic stress during soil moisture dry-down periods. The ...

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Section: Discussionmentioning

confidence: 84%

Representation of Plant Hydraulics in the Noah‐MP Land Surface Model: Model Development and Multiscale Evaluation

Yang

Matheny

et al. 2021

J Adv Model Earth Syst

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“…The Q n rates and their response to environmental parameters fluctuate among different plant species due to differences in morphological traits, growth conditions, plant functional types, habitats, plant water consumption behaviors, and tree height and crown diameter [35,36]. Likewise, large interspecific variations in Q n rates were observed among species growing over similar geographic areas [10].…”

Section: Introductionmentioning

confidence: 99%

Multiple-Temporal Scale Variations in Nighttime Sap Flow Response to Environmental Factors in Ficus concinna over a Subtropical Megacity, Southern China

Hayat

Yan

Xiang

et al. 2022

Forests

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With ongoing climate change and rapid urbanization, the influence of extreme weather conditions on long-term nocturnal sap flow (Qn) dynamics in subtropical urban tree species is poorly understood despite the importance of Qn for the water budgets and development plantation. We continuously measured nighttime sap flow in Ficus concinna over multiple years (2014–2020) in a subtropical megacity, Shenzhen, to explore the environmental controls on Qn and dynamics in plant water consumption at different timescales. Nocturnally, Qn was shown to be positively driven by the air temperature (Ta), vapor pressure deficit (VPD), and canopy conductance (expressed as a ratio of transpiration to VPD), yet negatively regulated by relative humidity (RH). Seasonally, variations in Qn were determined by VPD in fast growth, Ta, T/VPD, and meteoric water input to soils in middle growth, and RH in the terminal growth stages of the trees. Annual mean Qn varied from 2.87 to 6.30 kg d−1 with an interannual mean of 4.39 ± 1.43 kg d−1 (± standard deviation). Interannually, the key regulatory parameters of Qn were found to be Ta, T/VPD, and precipitation (P)-induced-soil moisture content (SMC), which individually explained 69, 63, 83, and 76% of the variation, respectively. The proportion of the nocturnal to the total 24-h sap flow (i.e., Qn/Q24-h × 100) ranged from 0.18 to 17.39%, with an interannual mean of 8.87%. It is suggested that high temperatures could increase transpirational demand and, hence, water losses during the night. Our findings can potentially assist in sustainable water management in subtropical areas and urban planning under increasing urban heat islands expected with future climate change.

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“…Paired with the shorter growing season of deciduous vegetation compared to evergreen canopies, shifts in sensible heat fluxes trend toward a warmer landscape, due in part to lower per leaf area transpiration rates characteristic of shrub canopies (Fang et al. ). Together, these changes in how the vegetation interacts with light and water decrease both ecosystem productivity and the total stocks of above‐ and belowground carbon storage.…”

Section: Introductionmentioning

confidence: 99%

“…Ecosystem light use is substantially reduced following these disturbances due to a combination of the large decrease in leaf area index (LAI) and transition to seasonal oscillation of LAI associated with deciduous plant phenology (Montes-Helu et al 2009). Paired with the shorter growing season of deciduous vegetation compared to evergreen canopies, shifts in sensible heat fluxes trend toward a warmer landscape, due in part to lower per leaf area transpiration rates characteristic of shrub canopies (Fang et al 2017). Together, these changes in how the vegetation interacts with light and water decrease both ecosystem productivity and the total stocks of above-and belowground carbon storage.…”

Section: Introductionmentioning

confidence: 99%

Allometric relationships for Quercus gambelii and Robinia neomexicana for biomass estimation following disturbance

2019

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In the southwestern USA, increases in size, frequency, and severity of wildfire are driving the conversion of forests to shrub‐dominated ecosystems. Increases in drought extent and severity, coupled with the way that shrub‐dominated systems are perpetuated by high‐severity fire, predisposes these post‐disturbance landscapes to remain in a non‐forest condition. Consequently, understanding the distribution of aboveground biomass in post‐disturbance, shrub‐dominated ecosystems is central to constraining the uncertainty surrounding how these ecosystems interact with light and water to sequester carbon. Here we present allometric regressions for Quercus gambelii (Gambel oak) and Robinia neomexicana (New Mexico locust), two species that dominate post‐fire landscapes in the southwestern USA. Our allometric regressions are designed to be driven by either field plot or high‐resolution remote sensing data, using either shrub area or shrub volume to estimate biomass.

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Responses of nighttime sap flow to atmospheric and soil dryness and its potential roles for shrubs on the Loess Plateau of China

Cited by 21 publications

References 55 publications

Representation of Plant Hydraulics in the Noah‐MP Land Surface Model: Model Development and Multiscale Evaluation

Representation of Plant Hydraulics in the Noah‐MP Land Surface Model: Model Development and Multiscale Evaluation

Multiple-Temporal Scale Variations in Nighttime Sap Flow Response to Environmental Factors in Ficus concinna over a Subtropical Megacity, Southern China

Allometric relationships for Quercus gambelii and Robinia neomexicana for biomass estimation following disturbance

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