Prediction of sap flux of elm (Ulmus pumila var. sabulosa) by solar induced fluorescence in a temperate savanna, China

Abstract

Tracking the sap flux of woody plants in savannas is essential for understanding their response to climate change and human management. Solar-induced fluorescence (SIF) has potential to predict transpiration yet its applicability for estimating savanna sap flux is unclear. Using three years of tower-based far-red SIF observations and ground-based sap flow monitoring in a temperate savanna of Otindag Sandy Land, China, we investigated the relationship between far-red SIF and sap flux density and developed linear and random forest models for estimating. The results show a variable correlation between SIF and sap flux density for Ulmus pumila var. sabulosa (J.H. Xin) G.H. Zhu & D.H. Bian (U. pumila.) at an hourly scale. The strongest correlations were during the mid- growth period July and August when considering the time lag between SIF and sap flux (0–0.5 h). Photosynthetically active radiation was the primary factor driving the SIF and sap flux density relationship. Soil moisture, vapor pressure deficit, and air temperature also influenced this relationship on daily and monthly scales. Compared to SIF-based linear regression models, the SIF-based random forest model performed better in tracking the seasonal sap flux density. The results suggest the feasibility of accurately monitoring vegetation sap flux using SIF, woody fractional vegetation cover, and environmental factors in a temperate savanna. This method could also be used in modeling land surface processes in savanna-type ecosystems.

Graphic abstract

Keywords

Temperate savanna / Ulmus pumila. / Far-red SIF / Sap flux relationships / Environmental factors

References

[1] Barron-GaffordGA, Sanchez-CañeteEP, MinorRL, HendryxSM, LeeE, SutterLF, TranN, ParraE, ColellaT, MurphyPC, HamerlynckEP, KumarP, ScottRL. Impacts of hydraulic redistribution on grass–tree competition vs facilitation in a semi-arid savanna. New Phytol, 2017, 215(4): 1451-1461

[2] BowlingDR, LoganBA, HufkensK, AubrechtDM, RichardsonAD, BurnsSP, AndereggWRL, BlankenPD, EirikssonDP. Limitations to winter and spring photosynthesis of a Rocky Mountain subalpine forest. Agric For Meteor, 2018, 252: 241-255

[3] BrilliF, HörtnaglL, HammerleA, HaslwanterA, HanselA, LoretoF, WohlfahrtG. Leaf and ecosystem response to soil water availability in mountain grasslands. Agric For Meteorol, 2011, 151(12): 1731-1740

[4] BrinkmannN, EugsterW, ZweifelR, BuchmannN, KahmenA. Temperate tree species show identical response in tree water deficit but different sensitivities in sap flow to summer soil drying. Tree Physiol, 2016, 36(12): 1508-1519

[5] BuJY, GanGJ, ChenJH, SuYX, YuanMJ, GaoYC, DomingoF, López-BallesterosA, MigliavaccaM, El-MadanyTS, GentineP, XiaoJF, GarciaM. Dryland evapotranspiration from remote sensing solar-induced chlorophyll fluorescence: constraining an optimal stomatal model within a two-source energy balance model. Remote Sens Environ, 2024, 303, ArticleID: 113999

[6] Burchard-LevineV, NietoH, RiañoD, KustasWP, MigliavaccaM, El-MadanyTS, NelsonJA, AndreuA, CarraraA, BeringerJ, BaldocchiD, Pilar MartínM. A remote sensing-based three-source energy balance model to improve global estimations of evapotranspiration in semi-arid tree-grass ecosystems. Glob Chang Biol, 2022, 28(4): 1493-1515

[7] BushSE, PatakiDE, HultineKR, WestAG, SperryJS, EhleringerJR. Wood anatomy constrains stomatal responses to atmospheric vapor pressure deficit in irrigated, urban trees. Oecologia, 2008, 156(1): 13-20

[8] ChangXX, ZhaoWZ, HeZB. Radial pattern of sap flow and response to microclimate and soil moisture in Qinghai spruce (Picea crassifolia) in the upper Heihe River Basin of arid northwestern China. Agric For Meteor, 2014, 187: 14-21

[9] ChangCY, GuanterL, FrankenbergC, KöhlerP, GuLH, MagneyTS, GrossmannK, SunY. Systematic assessment of retrieval methods for canopy far-red solar-induced chlorophyll fluorescence using high-frequency automated field spectroscopy. J Geophys Res Biogeosci, 2020, 125(7): e2019JG005533

[10] ChenZ, ZhangZQ, SunG, ChenLX, XuH, ChenSN. Biophysical controls on nocturnal sap flow in plantation forests in a semi-arid region of northern China. Agric For Meteor, 2020, 284, ArticleID: 107904

[11] CongWW, YangKJ, WangF. Canopy solar-induced chlorophyll fluorescence and its link to transpiration in a temperate evergreen needle leaf forest during the fall transition. Forests, 2022, 13(1): 74

[12] DammA, HaghighiE, Paul-LimogesE, van der TolC. On the seasonal relation of Sun-induced chlorophyll fluorescence and transpiration in a temperate mixed forest. Agric For Meteor, 2021, 304, ArticleID: 108386

[13] DawsonTE, BurgessSSO, TuKP, OliveiraRS, SantiagoLS, FisherJB, SimoninKA, AmbroseAR. Nighttime transpiration in woody plants from contrasting ecosystems. Tree Physiol, 2007, 27(4): 561-575

[14] DiN, XiBY, ClothierB, WangY, LiGD, JiaLM. Diurnal and nocturnal transpiration behaviors and their responses to groundwater-table fluctuations and meteorological factors of Populus tomentosa in the North China Plain. For Ecol Manag, 2019, 448: 445-456

[15] DietrichL, DelzonS, HochG, KahmenA. No role for xylem embolism or carbohydrate shortage in temperate trees during the severe 2015 drought. J Ecol, 2019, 107(1): 334-349

[16] DobsonA, HopcraftG, MdumaS, OgutuJO, FryxellJ, Michael AndersonT, ArchibaldS, LehmannC, PooleJ, CaroT, MulderMB, HoltRD, BergerJ, RubensteinDI, KahumbuP, ChidumayoEN, Milner-GullandEJ, SchluterD, OttoS, BalmfordA, WilcoveD, PimmS, VeldmanJW, OlffH, NossR, HoldoR, BealeC, HempsonG, KiwangoY, LindenmayerD, BondW, RitchieM, SinclairARE. Savannas are vital but overlooked carbon sinks. Science, 2022, 375(6579): 392

[17] DuS, WangYL, KumeT, ZhangJG, OtsukiK, YamanakaN, LiuGB. Sapflow characteristics and climatic responses in three forest species in the semiarid Loess Plateau region of China. Agric For Meteor, 2011, 151(1): 1-10

[18] DuSS, LiuLY, LiuXJ, HuJC. Response of canopy solar-induced chlorophyll fluorescence to the absorbed photosynthetically active radiation absorbed by chlorophyll. Remote Sens, 2017, 9(9): 911

[19] DuveillerG, CescattiA. Spatially downscaling Sun-induced chlorophyll fluorescence leads to an improved temporal correlation with gross primary productivity. Remote Sens Environ, 2016, 182: 72-89

[20] El-MadanyTS, ReichsteinM, Perez-PriegoO, CarraraA, MorenoG, Pilar MartínM, Pacheco-LabradorJ, WohlfahrtG, NietoH, WeberU, KolleO, LuoYP, CarvalhaisN, MigliavaccaM. Drivers of spatio-temporal variability of carbon dioxide and energy fluxes in a Mediterranean savanna ecosystem. Agric For Meteor, 2018, 262: 258-278

[21] ErshadiA, McCabeMF, EvansJP, ChaneyNW, WoodEF. Multi-site evaluation of terrestrial evaporation models using FLUXNET data. Agric For Meteor, 2014, 187: 46-61

[22] FengX, AckerlyDD, DawsonTE, ManzoniS, McLaughlinB, SkeltonRP, VicoG, WeitzAP, ThompsonSE. Beyond isohydricity: The role of environmental variability in determining plant drought responses. Plant Cell Environ, 2019, 42(4): 1104-1111

[23] FengHZ, XuTR, LiuLY, ZhouS, ZhaoJX, LiuSM, XuZW, MaoKB, HeXL, ZhuZL, ChaiLN. Modeling transpiration with Sun-induced chlorophyll fluorescence observations via carbon-water coupling methods. Remote Sens, 2021, 13(4): 804

[24] FrickeW. Night-time transpiration–favouring growth?. Trends Plant Sci, 2019, 24(4): 311-317

[25] GanGJ, KangTT, YangS, BuJY, FengZM, GaoYC. An optimized two source energy balance model based on complementary concept and canopy conductance. Remote Sens Environ, 2019, 223: 243-256

[26] Garcia-FornerN, AdamsHD, SevantoS, CollinsAD, DickmanLT, HudsonPJ, ZeppelMJB, JenkinsMW, PowersH, Martínez-VilaltaJ, McDowellNG. Responses of two semiarid conifer tree species to reduced precipitation and warming reveal new perspectives for stomatal regulation. Plant Cell Environ, 2016, 39(1): 38-49

[27] GentineP, AlemohammadSH. Reconstructed solar-induced fluorescence: a machine learning vegetation product based on MODIS surface reflectance to reproduce GOME-2 solar-induced fluorescence. Geophys Res Lett, 2018, 45(7): 3136-3146

[28] GranierA. Evaluation of transpiration in a Douglas-fir stand by means of sap flow measurements. Tree Physiol, 1987, 3(4): 309-320

[29] GranierA, AnfodilloT, SabattiM, CochardH, DreyerE, TomasiM, ValentiniR, BrédaN. Axial and radial water flow in the trunks of oak trees: a quantitative and qualitative analysis. Tree Physiol, 1994, 14(12): 1383-1396

[30] GranierA, BironP, BrédaN, PontaillerJY, SaugierB. Transpiration of trees and forest stands: short and long-term monitoring using sapflow methods. Glob Change Biol, 1996, 2(3): 265-274

[31] GuLH, HanJM, WoodJD, ChangCY, SunY. Sun-induced Chl fluorescence and its importance for biophysical modeling of photosynthesis based on light reactions. New Phytol, 2019, 223(3): 1179-1191

[32] GuLH, GrodzinskiB, HanJM, MarieT, ZhangYJ, SongYC, SunY. An exploratory steady-state redox model of photosynthetic linear electron transport for use in complete modelling of photosynthesis for broad applications. Plant Cell Environ, 2023, 46(5): 1540-1561

[33] HackeUG, SperryJS, WheelerJK, CastroL. Scaling of angiosperm xylem structure with safety and efficiency. Tree Physiol, 2006, 26(6): 689-701

[34] HölttäT, Dominguez CarrascoMDR, SalmonY, AaltoJ, VanhataloA, BäckJ, LintunenA. Water relations in silver birch during springtime: How is sap pressurised?. Plant Biol, 2018, 20(5): 834-847

[35] JasechkoS, SharpZD, GibsonJJ, Jean BirksS, YiY, FawcettPJ. Terrestrial water fluxes dominated by transpiration. Nature, 2013, 496(7445): 347-350

[36] JonardF, De CannièreS, BrüggemannN, GentineP, Short GianottiDJ, LobetG, MirallesDG, MontzkaC, PagánBR, RascherU, VereeckenH. Value of Sun-induced chlorophyll fluorescence for quantifying hydrological states and fluxes: current status and challenges. Agric For Meteor, 2020, 291, ArticleID: 108088

[37] JoshiJ, StockerBD, HofhanslF, ZhouSX, DieckmannU, PrenticeIC. Towards a unified theory of plant photosynthesis and hydraulics. Nat Plants, 2022, 8(11): 1304-1316

[38] KhanMF, SulaimanM, AlshammariFS. A hybrid heuristic-driven technique to study the dynamics of savanna ecosystem. Stoch Environ Res Risk Assess, 2023, 37(1): 1-25

[39] KimD, OrenR, OishiAC, HsiehCI, PhillipsN, NovickKA, StoyPC. Sensitivity of stand transpiration to wind velocity in a mixed broadleaved deciduous forest. Agric For Meteor, 2014, 187: 62-71

[40] KoningsAG, GentineP. Global variations in ecosystem-scale isohydricity. Glob Chang Biol, 2017, 23(2): 891-905

[41] KöstnerB, GranierA, CermákJ. Sapflow measurements in forest stands: methods and uncertainties. Ann for Sci, 1998, 55(1–2): 13-27

[42] LeuningR, DuninFX, WangYP. A two-leaf model for canopy conductance, photosynthesis and partitioning of available energy. II. Comparison with measurements. Agric For Meteor, 1998, 91(12): 113-125

[43] LiX, XiaoJF. A global, 0.05-degree product of solar-induced chlorophyll fluorescence derived from OCO-2, MODIS, and reanalysis data. Remote Sens, 2019, 11(5): 517

[44] LiYG, JiangGM, LiuMZ, NiuSL, GaoLM, CaoXC. Photosynthetic response to precipitation/rainfall in predominant tree (Ulmus pumila) seedlings in Hunshandak Sandland. China Photosynthetica, 2007, 45(1): 133-138

[45] LianX, PiaoSL, HuntingfordC, LiY, ZengZZ, WangXH, CiaisP, McVicarTR, PengSS, OttléC, YangH, YangYT, ZhangYQ, WangT. Partitioning global land evapotranspiration using CMIP5 models constrained by observations. Nat Clim Change, 2018, 8(7): 640-646

[46] LiuYJ, ZhangYG, ShanN, ZhangZY, WeiZW. Global assessment of partitioning transpiration from evapotranspiration based on satellite solar-induced chlorophyll fluorescence data. J Hydrol, 2022, 612, ArticleID: 128044

[47] LouJP, WangXM, CaiDW. Spatial and temporal variation of wind erosion climatic erosivity and its response to ENSO in the otindag desert. China Atmosphere, 2019, 10(10): 614

[48] LuP, MüllerWJ, ChackoEK. Spatial variations in xylem sap flux density in the trunk of orchard-grown, mature mango trees under changing soil water conditions. Tree Physiol, 2000, 20(10): 683-692

[49] LuP, UrbanL, PingZ. Granier’s thermal dissipation probe (TDP) method for measuring sap flow in trees: theory and practice. Acta Bot Sin, 2004, 46(6): 631-646

[50] LuXL, LiuZQ, AnSQ, MirallesDG, MaesW, LiuYL, TangJW. Potential of solar-induced chlorophyll fluorescence to estimate transpiration in a temperate forest. Agric For Meteor, 2018, 252: 75-87

[51] MaCK, LuoY, ShaoMG, LiXD, SunL, JiaXX. Environmental controls on sap flow in black locust forest in Loess Plateau. China Sci Rep, 2017, 7(1): 13160

[52] MaesWH, PagánBR, MartensB, GentineP, GuanterL, SteppeK, VerhoestNEC, DorigoW, LiX, XiaoJF, MirallesDG. Sun-induced fluorescence closely linked to ecosystem transpiration as evidenced by satellite data and radiative transfer models. Remote Sens Environ, 2020, 249, ArticleID: 112030

[53] MartiniD, SakowskaK, WohlfahrtG, Pacheco-LabradorJ, van der TolC, Porcar-CastellA, MagneyTS, CarraraA, ColomboR, El-MadanyTS, Gonzalez-CasconR, MartínMP, JulittaT, MorenoG, RascherU, ReichsteinM, RossiniM, MigliavaccaM. Heatwave breaks down the linearity between Sun-induced fluorescence and gross primary production. New Phytol, 2022, 233(6): 2415-2428

[54] McDowellN, PockmanWT, AllenCD, BreshearsDD, CobbN, KolbT, PlautJ, SperryJ, WestA, WilliamsDG, YepezEA. Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought?. New Phytol, 2008, 178(4): 719-739

[55] MiaoGF, GuanKY, SuykerAE, YangX, ArkebauerTJ, Walter-SheaEA, KimmH, HmiminaGY, GamonJA, FranzTE, FrankenbergC, BerryJA, WuGH. Varying contributions of drivers to the relationship between canopy photosynthesis and far-red Sun-induced fluorescence for two maize sites at different temporal scales. J Geophys Res Biogeosci, 2020, 125(2): e2019JG005051

[56] MohammedGH, ColomboR, MiddletonEM, RascherU, van der TolC, NedbalL, GoulasY, Pérez-PriegoO, DammA, MeroniM, JoinerJ, CogliatiS, VerhoefW, MalenovskýZ, Gastellu-EtchegorryJP, MillerJR, GuanterL, MorenoJ, MoyaI, BerryJA, FrankenbergC, Zarco-TejadaPJ. Remote sensing of solar-induced chlorophyll fluorescence (SIF) in vegetation: 50 years of progress. Remote Sens Environ, 2019, 231, 111177

[57] MonsonRK, SparksJP, RosenstielTN, Scott-DentonLE, HuxmanTE, HarleyPC, TurnipseedAA, BurnsSP, BacklundB, HuJ. Climatic influences on net ecosystem CO₂ exchange during the transition from wintertime carbon source to springtime carbon sink in a high-elevation, subalpine forest. Oecologia, 2005, 146(1): 130-147

[58] MyneniRB, WilliamsDL. On the relationship between FAPAR and NDVI. Remote Sens Environ, 1994, 49(3): 200-211

[59] NovickKA, MiniatCF, VoseJM. Drought limitations to leaf-level gas exchange: results from a model linking stomatal optimization and cohesion-tension theory. Plant Cell Environ, 2016, 39(3): 583-596

[60] PagánB, MaesW, GentineP, MartensB, MirallesD. Exploring the potential of satellite solar-induced fluorescence to constrain global transpiration estimates. Remote Sens, 2019, 11(4): 413

[61] PhillipsN, OrenR, ZimmermannR, WrightSJ. Temporal patterns of water flux in trees and lianas in a Panamanian moist forest. Trees, 1999, 14(3): 116-123

[62] Porcar-CastellA, TyystjärviE, AthertonJ, van der TolC, FlexasJ, PfündelEE, MorenoJ, FrankenbergC, BerryJA. Linking chlorophyll a fluorescence to photosynthesis for remote sensing applications: mechanisms and challenges. J Exp Bot, 2014, 65(15): 4065-4095

[63] PoyatosR, GrandaV, Molowny-HorasR, MencucciniM, SteppeK, Martínez-VilaltaJ. SAPFLUXNET: towards a global database of sap flow measurements. Tree Physiol, 2016, 36(12): 1449-1455

[64] ShanN, JuWM, MigliavaccaM, MartiniD, GuanterL, ChenJM, GoulasY, ZhangYG. Modeling canopy conductance and transpiration from solar-induced chlorophyll fluorescence. Agric For Meteor, 2019, 268: 189-201

[65] ShanN, ZhangYG, ChenJM, JuWM, MigliavaccaM, PeñuelasJ, YangX, ZhangZY, NelsonJA, GoulasY. A model for estimating transpiration from remotely sensed solar-induced chlorophyll fluorescence. Remote Sens Environ, 2021, 252, ArticleID: 112134

[66] ShenQ, GaoGY, FuBJ, LüYH. Sap flow and water use sources of shelter-belt trees in an arid inland river basin of Northwest China. Ecohydrology, 2015, 8(8): 1446-1458

[67] SmithWK, DannenbergMP, YanD, HerrmannS, BarnesML, Barron-GaffordGA, BiedermanJA, FerrenbergS, FoxAM, HudsonA, KnowlesJF, MacBeanN, MooreDJP, NaglerPL, ReedSC, RutherfordWA, ScottRL, WangX, YangJL. Remote sensing of dryland ecosystem structure and function: Progress, challenges, and opportunities. Remote Sens Environ, 2019, 233, ArticleID: 111401

[68] SongLN, ZhuJJ, ZhengX, LiX, WangK, ZhangJX, WangGC, SunHH. Water use dynamics of trees in a Pinus tabuliformis plantation in semiarid sandy regions. NorthEast China Agric Water Manag, 2023, 275, ArticleID: 107995

[69] SpringerK, WangR, GamonJ. Parallel seasonal patterns of photosynthesis, fluorescence, and reflectance indices in boreal trees. Remote Sens, 2017, 9(7): 691

[70] StoyPC, El-MadanyTS, FisherJB, GentineP, GerkenT, GoodSP, KlosterhalfenA, LiuSG, MirallesDG, Perez-PriegoO, RigdenAJ, SkaggsTH, WohlfahrtG, AndersonRG, Coenders-GerritsAMJ, JungM, MaesWH, MammarellaI, MauderM, MigliavaccaM, NelsonJA, PoyatosR, ReichsteinM, ScottRL, WolfS. Reviews and syntheses: Turning the challenges of partitioning ecosystem evaporation and transpiration into opportunities. Biogeosciences, 2019, 16(19): 3747-3775

[71] SunY, GuLH, WenJM, van der TolC, Porcar-CastellA, JoinerJ, ChangCY, MagneyT, WangLX, HuLQ, RascherU, Zarco-TejadaP, BarrettCB, LaiJM, HanJM, LuoZQ. From remotely sensed solar-induced chlorophyll fluorescence to ecosystem structure, function, and service: Part I—Harnessing theory. Glob Change Biol, 2023, 29(11): 2926-2952

[72] TanedaH, SperryJS. A case-study of water transport in co-occurring ring- versus diffuse-porous trees: contrasts in water-status, conducting capacity, cavitation and vessel refilling. Tree Physiol, 2008, 28(11): 1641-1651

[73] TieQ, HuHC, TianFQ, GuanHD, LinH. Environmental and physiological controls on sap flow in a subhumid mountainous catchment in North China. Agric For Meteor, 2017, 240: 46-57

[74] TobinRL, KulmatiskiA. Plant identity and shallow soil moisture are primary drivers of stomatal conductance in the savannas of Kruger National Park. PLoS ONE, 2018, 13(1) e0191396

[75] ViñaA, GitelsonAA. New developments in the remote estimation of the fraction of absorbed photosynthetically active radiation in crops. Geophys Res Lett, 2005, 32 17): L17403

[76] WaltherS, VoigtM, ThumT, GonsamoA, ZhangYG, KöhlerP, JungM, VarlaginA, GuanterL. Satellite chlorophyll fluorescence measurements reveal large-scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests. Glob Chang Biol, 2016, 22(9): 2979-2996

[77] WangYP, LeuningR. A two-leaf model for canopy conductance, photosynthesis and partitioning of available energy I: Model description and comparison with a multi-layered model. Agric For Meteor, 1998, 91(1–2): 89-111

[78] WangHZ, HanD, MuY, JiangLN, YaoXL, BaiYF, LuQ, WangF. Landscape-level vegetation classification and fractional woody and herbaceous vegetation cover estimation over the dryland ecosystems by unmanned aerial vehicle platform. Agric For Meteor, 2019, 278, ArticleID: 107665

[79] WeiZW, YoshimuraK, WangLX, MirallesDG, JasechkoS, LeeXH. Revisiting the contribution of transpiration to global terrestrial evapotranspiration. Geophys Res Lett, 2017, 44(6): 2792-2801

[80] WenJ, KöhlerP, DuveillerG, ParazooNC, MagneyTS, HookerG, YuL, ChangCY, SunY. A framework for harmonizing multiple satellite instruments to generate a long-term global high spatial-resolution solar-induced chlorophyll fluorescence (SIF). Remote Sens Environ, 2020, 239, ArticleID: 111644

[81] WhitleyR, BeringerJ, HutleyLB, AbramowitzG, De KauweMG, EvansB, HaverdV, LiLH, MooreC, RyuY, ScheiterS, SchymanskiSJ, SmithB, WangY-P, WilliamsM, YuQ. Challenges and opportunities in land surface modelling of savanna ecosystems. Biogeosciences, 2017, 14(20): 4711-4732

[82] WuGH, GuanKY, LiY, NovickKA, FengX, McDowellNG, KoningsAG, ThompsonSE, KimballJS, De KauweMG, AinsworthEA, JiangCY. Interannual variability of ecosystem Iso/anisohydry is regulated by environmental dryness. New Phytol, 2021, 229(5): 2562-2575

[83] XingWQ, WangWG, ShaoQX, SongLY, CaoMZ. Estimation of evapotranspiration and its components across China based on a modified Priestley-Taylor algorithm using monthly multi-layer soil moisture data. Remote Sens, 2021, 13(16): 3118

[84] YangX, TangJW, MustardJF, LeeJE, RossiniM, JoinerJ, MungerJW, KornfeldA, RichardsonAD. Solar-induced chlorophyll fluorescence that correlates with canopy photosynthesis on diurnal and seasonal scales in a temperate deciduous forest. Geophys Res Lett, 2015, 42(8): 2977-2987

[85] YangX, ShiHY, StovallA, GuanKY, MiaoGF, ZhangYG, ZhangY, XiaoXM, RyuY, LeeJE. FluoSpec 2-an automated field spectroscopy system to monitor canopy solar-induced fluorescence. Sensors, 2018, 18(7): 2063

[86] YangPQ, van der TolC, CampbellPKE, MiddletonEM. Fluorescence correction vegetation index (FCVI): a physically based reflectance index to separate physiological and non-physiological information in far-red Sun-induced chlorophyll fluorescence. Remote Sens Environ, 2020, 240, ArticleID: 111676

[87] YangJJ, LiuZQ, YuQ, LuXL. Estimation of global transpiration from remotely sensed solar-induced chlorophyll fluorescence. Remote Sens Environ, 2024, 303, ArticleID: 113998

[88] YuL, WenJ, ChangCY, FrankenbergC, SunY. High-resolution global contiguous SIF of OCO-2. Geophys Res Lett, 2019, 46(3): 1449-1458

[89] Zarco-TejadaPJ, González-DugoV, BerniJAJ. Fluorescence, temperature and narrow-band indices acquired from a UAV platform for water stress detection using a micro-hyperspectral imager and a thermal camera. Remote Sens Environ, 2012, 117: 322-337

[90] ZengYL, BadgleyG, DechantB, RyuY, ChenM, BerryJA. A practical approach for estimating the escape ratio of near-infrared solar-induced chlorophyll fluorescence. Remote Sens Environ, 2019, 232, ArticleID: 111209

[91] ZeppelMJB, MurrayBR, BartonC, EamusD. Seasonal responses of xylem sap velocity to VPD and solar radiation during drought in a stand of native trees in temperate Australia. Funct Plant Biol, 2004, 31(5): 461-470

[92] ZhangK, KimballJS, RunningSW. A review of remote sensing based actual evapotranspiration estimation. Wiley Interdiscip Rev Water, 2016, 3(6): 834-853

[93] ZhangY, JoinerJ, AlemohammadSH, ZhouS, GentineP. A global spatially contiguous solar-induced fluorescence (CSIF) dataset using neural networks. Biogeosciences, 2018, 15(19): 5779-5800

[94] ZhengCL, WangQ. Water-use response to climate factors at whole tree and branch scale for a dominant desert species in central Asia: Haloxylon ammodendron. Ecohydrology, 2014, 7(1): 56-63

[95] ZhengC, WangSQ, ChenJM, XiaoJF, ChenJH, ZhuK, SunLG. Modeling transpiration using solar-induced chlorophyll fluorescence and photochemical reflectance index synergistically in a closed-canopy winter wheat ecosystem. Remote Sens Environ, 2024, 302, ArticleID: 113981

[96] ZhouK, ZhangQ, XiongLH, GentineP. Estimating evapotranspiration using remotely sensed solar-induced fluorescence measurements. Agric For Meteor, 2022, 314, ArticleID: 108800

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