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RESEARCH PRODUCT
The 2013 FLEX—US Airborne Campaign at the Parker Tract Loblolly Pine Plantation in North Carolina, USA
Asko NoormetsDirk SchüttemeyerAlexander DammUwe RascherR. BianchiRoberto ColomboKarl F. HuemmrichElizabeth M. MiddletonDavid R. LandisBruce D. CookLuis GuanterQingyuan ZhangMicol RossiniPetya K. E. CampbellAnke SchicklingLawrence A. CorpFrancisco De Assis De Carvalho PintoLuis Alonsosubject
Canopychlorophyll fluorescence; diurnal responses; red SIF; far-red SIF; SIF ratio; Fratio; <i>HyPlant</i>; G-LiHT; GEP; LUE010504 meteorology & atmospheric sciencesLiHTChronosequence0211 other engineering and technologies02 engineering and technologyfarPhotochemical Reflectance IndexAtmospheric sciences01 natural sciencesGDiurnal cycleLUEdiurnal responses910 Geography & travelChlorophyll fluorescence021101 geological & geomatics engineering0105 earth and related environmental sciencesHydrologyTree canopychlorophyll fluorescenceG-LiHT1900 General Earth and Planetary SciencesVegetationGEPSIF ratioFar-red SIFFratio10122 Institute of GeographyLidarDiurnal responseHyPlantGeneral Earth and Planetary SciencesEnvironmental sciencered SIFEarth and Planetary Sciences (all)description
The first European Space Agency (ESA) and NASA collaboration in an airborne campaign to support ESA’s FLuorescence EXplorer (FLEX) mission was conducted in North Carolina, USA during September–October 2013 (FLEX-US 2013) at the Parker Tract Loblolly Pine (LP) Plantation (Plymouth, NC, USA). This campaign combined two unique airborne instrument packages to obtain simultaneous observations of solar-induced fluorescence (SIF), LiDAR-based canopy structural information, visible through shortwave infrared (VSWIR) reflectance spectra, and surface temperature, to advance vegetation studies of carbon cycle dynamics and ecosystem health. We obtained statistically significant results for fluorescence, canopy temperature, and tower fluxes from data collected at four times of day over two consecutive autumn days across an age class chronosequence. Both the red fluorescence (F685) and far-red fluorescence (F740) radiances had highest values at mid-day, but their fluorescence yields exhibited different diurnal responses across LP age classes. The diurnal trends for F685 varied with forest canopy temperature difference (canopy minus air), having a stronger daily amplitude change for young vs. old canopies. The Photochemical Reflectance Index (PRI) was positively correlated with this temperature variable over the diurnal cycle. Tower measurements from mature loblolly stand showed the red/far-red fluorescence ratio was linearly related to canopy light use efficiency (LUE) over the diurnal cycle, but performed even better for the combined morning/afternoon (without midday) observations. This study demonstrates the importance of diurnal observations for interpretation of fluorescence dynamics, the need for red fluorescence to understand canopy physiological processes, and the benefits of combining fluorescence, reflectance, and structure information to clarify canopy function versus structure characteristics for a coniferous forest.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-06-16 |