Transit times—the link between hydrology and water quality at the catchment scale

Wiley Interdisciplinary Reviews Water, Journal Year: 2016, Volume and Issue: 3(5), P. 629 - 657

Published: May 16, 2016

In spite of trying to understand processes in the same spatial domain, catchment hydrology and water quality scientific communities are relatively disconnected so their respective models. This is emphasized by an inadequate representation transport processes, both catchment‐scale hydrological While many models at scale only account for pressure propagation not mass transfer, typically limited overly simplistic representations flow processes. With objective raising awareness this issue outlining potential ways forward we provide a nontechnical overview (1) importance hydrology‐controlled through systems as link between quality; (2) limitations current generation models; (3) concept transit times tools quantify transport; (4) benefits time based formulations solute There emerging evidence that explicit formulation on has improve understanding integrated system dynamics catchments stronger WIREs Water 2016, 3:629–657. doi: 10.1002/wat2.1155 article categorized under: Science > Hydrological Processes Quality

Language: Английский

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Modelling carbon sources and sinks in terrestrial vegetation

New Phytologist, Journal Year: 2018, Volume and Issue: 221(2), P. 652 - 668

Published: Oct. 19, 2018

Contents Summary 652 I. Introduction II. Discrepancy in predicting the effects of rising [CO 2 ] on terrestrial C sink 655 III. Carbon and nutrient storage plants its modelling 656 IV. Modelling source sink: a plant perspective 657 V. Plant‐scale water flux models 660 VI. Challenges for future 662 Acknowledgements 663 Authors contributions References The increase atmospheric CO is one most certain projections environmental sciences. Understanding whether vegetation carbon assimilation, growth, changes stocks are affected by higher translating this understanding mechanistic utmost importance. This highlighted inconsistencies between global‐scale studies that attribute sinks to stimulation gross net primary production hand, forest inventories, tree‐scale studies, physiological evidence showing much less pronounced fertilization effect other hand. Here, we review how sources currently described biosphere models. We highlight an uneven representation complexity photosynthesis processes, such as respiration, direct sinks, allocation, largely driven available observations. Despite general lack data dynamics drive model improvements, ways forward toward discussed, leveraging results obtained from plant‐scale observations geared developments.

Language: Английский

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More green and less blue water in the Alps during warmer summers

Nature Climate Change, Journal Year: 2020, Volume and Issue: 10(2), P. 155 - 161

Published: Jan. 27, 2020

Language: Английский

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Soil structure is an important omission in Earth System Models

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: Jan. 27, 2020

Abstract Most soil hydraulic information used in Earth System Models (ESMs) is derived from pedo-transfer functions that use easy-to-measure attributes to estimate parameters. This parameterization relies heavily on texture, but overlooks the critical role of structure originated by biophysical activity. Soil omission pervasive also sampling and measurement methods train pedotransfer functions. Here we show how systematic inclusion salient structural features origin affect local global hydrologic climatic responses. Locally, including models significantly alters infiltration-runoff partitioning recharge wet vegetated regions. Globally, coarse spatial resolution ESMs their inability simulate intense short rainfall events mask effects surface fluxes climate. Results suggest although affects response, its implications global-scale climate remains elusive current ESMs.

Language: Английский

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Modelling water fluxes in plants: from tissues to biosphere

New Phytologist, Journal Year: 2019, Volume and Issue: 222(3), P. 1207 - 1222

Published: Jan. 13, 2019

Summary Models of plant water fluxes have evolved from studies focussed on understanding the detailed structure and functioning specific components soil–plant–atmosphere ( SPA ) continuum to architectures often incorporated inside eco‐hydrological terrestrial biosphere TB model schemes. We review here historical evolution this field, examine basic a simplified individual‐based transport, highlight selected applications for ecological problems conclude by examining outstanding issues requiring further improvements in modelling vegetation fluxes. particularly emphasise related scaling tissue‐level traits predictions representation nonlinear hysteretic behaviour soil–xylem hydraulics need incorporate knowledge within broader frameworks strategies their consequences predicting community demography dynamics.

Language: Английский

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The Impacts of Droughts in Tropical Forests

Trends in Plant Science, Journal Year: 2016, Volume and Issue: 21(7), P. 584 - 593

Published: March 16, 2016

Language: Английский

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Vegetation expansion in the subnival Hindu Kush Himalaya

Global Change Biology, Journal Year: 2020, Volume and Issue: 26(3), P. 1608 - 1625

Published: Jan. 9, 2020

The mountain systems of the Hindu Kush Himalaya (HKH) are changing rapidly due to climatic change, but an overlooked component is subnival ecosystem (between treeline and snow line), characterized by short-stature plants seasonal snow. Basic information about vegetation distribution rates change not known, yet such needed understand relationships between ecology water/carbon cycles. We show that HKH ecosystems cover five 15 times area permanent glaciers snow, highlighting their eco-hydrological importance. Using satellite data from Landsat 5, 7 8 missions, we measured in spatial extent 1993 2018. surface reflectance-derived Normalized Difference Vegetation Index product was thresholded at 0.1 indicate presence/absence vegetation. this product, strength direction time-series trends green pixel fraction were within three regions interest. controlled for cloud cover, evaluated impact sensor radiometric differences 8. Google Earth Engine expedite processing tasks, there has been a weakly positive increase since 1993. Strongest most significant found height region 5,000-5,500 m a.s.l. across extent: R2 = .302, Kendall's τ 0.424, p < .05, varied regionally, with height, according sensors included time series. Positive lower elevations occurred on steeper slopes whilst higher elevations, flatter areas exhibited stronger trends. validated our findings using online photographs. Subnival ecological changes have likely impacted carbon water cycles impacts millions people living downstream, expansion remain unknown.

Language: Английский

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

Journal of Advances in Modeling Earth Systems, Journal Year: 2021, Volume and Issue: 13(4)

Published: Feb. 6, 2021

Abstract 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 regulate and carbon fluxes in response soil moisture through empirical hydraulics schemes (SHSs). However, such have been shown cause significant uncertainties simulations. In this paper, we present a novel plant scheme (PHS) for Noah‐MP (hereafter, Noah‐MP‐PHS), which employs big‐tree rather than big‐leaf concept, wherein the whole‐plant hydraulic strategy is considered, root‐level acquisition, stem‐level conductance capacitance, leaf‐level anisohydricity capacitance. Evaluated against plot‐level observations from mature, mixed hardwood forest at University of Michigan Biological Station compared with default Noah‐MP‐PHS better represents improves simulations, especially during periods dry conditions. also asymmetrical diel simulation gross primary production low able reproduce different patterns transpiration, stem storage root uptake 2‐week dry‐down period two species contrasting behaviors, i.e., “cavitation risk‐averse” red maple risk‐prone” oak. Sensitivity experiments capacitance show that enables nocturnal recharge, affects use efficiency, provides important buffer relieve xylem

Language: Английский

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Global transpiration data from sap flow measurements: the SAPFLUXNET database

Earth system science data, Journal Year: 2021, Volume and Issue: 13(6), P. 2607 - 2649

Published: June 14, 2021

Abstract. Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, carbon budgets at the land–atmosphere interface. However, despite being main land evaporative flux global scale, its response environmental drivers are currently not well constrained by observations. Here we introduce first compilation whole-plant data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized quality-controlled individual datasets supplied contributors worldwide in a semi-automatic workflow implemented R programming language. Datasets include sub-daily time series hydrometeorological for one or more growing seasons, as metadata on stand characteristics, plant attributes, technical details measurements. SAPFLUXNET contains 202 globally distributed 2714 plants, mostly trees, 174 species. has broad bioclimatic coverage, woodland/shrubland temperate forest biomes especially represented (80 % datasets). The cover wide variety structural characteristics sizes. encompass period between 1995 2018, 50 least 3 years long. Accompanying radiation vapour pressure deficit available most datasets, while on-site soil content is 56 datasets. Many contain species that make up 90 total basal area, allowing estimation diverse ecological settings. adds existing trait ecosystem networks, remote sensing products help increase our understanding use, drought, ecohydrological processes. version 0.1.5 freely Zenodo repository (https://doi.org/10.5281/zenodo.3971689; Poyatos et al., 2020a). “sapfluxnetr” package – designed access, visualize, process CRAN.

Language: Английский

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Characterizing uncertainty in process-based hydraulic modeling, exemplified in a semiarid Inner Mongolia steppe

Geoderma, Journal Year: 2023, Volume and Issue: 440, P. 116713 - 116713

Published: Nov. 16, 2023

Assessing root sources of three uncertainties – parameterization soil hydraulic characteristics, boundary conditions, and estimation source/sink terms is a significant challenge in water transport modeling. This study aims to evaluate the uncertainty each widely-used parameter methods affecting plot-scale dynamics. The employs HYDRUS, process-based hydrologic model, incorporate these compare model predictions measured values semiarid Inner Mongolia steppe, China. Soil parameters are determined using two direct (laboratory-derived approach evaporation method) one indirect method (neural network). While generally simulates moisture dynamics, performed better, especially under dry conditions. suggests that measuring intensity properties, such as unsaturated conductivity, with crucial for reasonable simulation. also demonstrates impact different applied conditions on simulated moisture, specifically partitioning reference FAO evapotranspiration via (soil fraction cover) (leaf area index crop height). cover reflected better Additionally, compares uptake function growth constant depth referenced grass pasture, finds no difference among them. Comparing predicting concludes input more sensitive than or representation function. Our highlights properties can reflect effects land use change, compaction, field transports.

Language: Английский

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