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@MASTERSTHESIS{Busch:872668,
author = {Busch, Carsten},
othercontributors = {Krieger, Vera and Rascher, Uwe},
title = {{U}ntersuchungen von nicht-destruktiven {V}erfahren zur
{M}essung von {K}ohlenstoffakkumulation in {P}flanzen:
{S}onneninduzierte {C}hlorophyllfluoreszenz und
{E}ddy-{K}ovarianz},
school = {Köln},
type = {Masterarbeit},
reportid = {FZJ-2020-00159},
pages = {91 p.},
year = {2019},
note = {Masterarbeit, Köln, 2019},
abstract = {Vegetation drives 90 $\%$ of the gas exchange between
biosphere and atmosphere resulting in the dependency of
vital vegetation for stable gas concentrations in the
atmosphere. The commonly used method for measuring gas
fluxes is eddy covariance (EC), which measures the
difference between incoming and outcoming gas and specifies
these measurements on a source region called footprint.
Another method for quantifying gas fluxes is sun-induced
chlorophyll fluorescence (SIF), which is an electromagnetic
signal in a spectral region between 640 and 800 nm emitted
by plants during photosynthesis. SIF correlates strongly
with the photosynthetic efficiency and therefore with the
assimilation of carbon. In the following thesis a new method
for linking SIF with gross primary production (GPP) is
postulated. The Method uses the EC-Footprint for spatially
weighting SIF and GPP. The used footprints were subsequently
divided in different percentages. The aim of this thesis is
the analysis of the correlation between SIF and GPP
regarding the use of different percentages of the EC
footprint. Hyperspectral scenes were taken with the sensor
HyPlant on four days during summer of 2018. With these
scenes SIF can be estimated due to the iFLD method which
uses two oxygen absorption bands at 678 and 760 nm. Two
additional SIF products were considered: F Ratio describes
the ratio between the estimated F 687 and F 760 . F tot is
characterized by the total Fluorescence of the entire
emission spectrum. GPP were estimated with the measured net
ecosystem exchange (NEE) by the method of REICHSTEIN et al.
(2005). The estimation of the footprints was calculated by
the method of KORMANN $\&$ MEIXNER (2001). A script written
in python spatially matched and read the different data
sets. Afterwards the script exported values of GPP and SIF
for different percentages of the footprint, which were used
to calculate the coefficient of determination per percentage
per statio per SIF product. The results show a strong
correlation with the use of small percentages of the
footprint for the northern station, while the southern and
both stations combined show no or small correlation in all
percentages of the footprint. The extent of the fields could
play an important role in the calculations due to the larger
extent of the footprints. Higher percentages overlap the
fields boundaries and therefore bordering plant species
could manipulate the results. However, the results of the
northern station show a possible use of the method for
future investigations.},
cin = {IBG-2},
cid = {I:(DE-Juel1)IBG-2-20101118},
pnm = {582 - Plant Science (POF3-582)},
pid = {G:(DE-HGF)POF3-582},
typ = {PUB:(DE-HGF)19},
url = {https://juser.fz-juelich.de/record/872668},
}