Canopy transpiration of beech forests in Northern Bavaria [Elektronische Ressource] : structure and function in pure and mixed stands with oak at colline and montane sites / vorgelegt von Markus W. T. Schmidt

Canopytranspirationfeechforestsnorthernavaria –
Structureandunctionnureandixedstandsithak
atcollineandontane
ites
Dissertation
zur
Erlangung
der
Doktorwürde
(Dr.
rer.
nat.)
der
Fakultät
für
Biologie,
Chemie
und
Geowissenschaften
der
Universität
Bayreuth
vorgelegt
von
Markus
W.T.
Schmidt
aus
Düsseldorf
Bayreuth,
November
2007Die
vorliegende
Arbeit
wurde
zwischen
Februar
1998
und
November
2007
am
Lehrstuhl
für
Pflanzenökologie
der
Universität
Bayreuth
unter
Anleitung
von
Herrn
Prof.
John
D.
Tenhunen
(Ph.D.)
angefertigt.
Vollständiger
Abdruck
der
von
der
Fakultät
für
Biologie,
Chemie
und
Geowissen7
schaften
der
Universität
Bayreuth
genehmigten
Dissertation
zur
Erlangung
des
akademischen
Grades
eines
Doktors
der
Naturwissenschaften
(Dr.
rer.
nat.).
Antrag
auf
Zulassung
der
Dissertation:
30.
November
2007
Wissenschaftliches
Kolloquium:
15.
Februar
2008
Erstgutachter:
Prof.
J.D.
Tenhunen
(Ph.D.)
Zweitgutachter:
Prof.
Dr.
E.
Komori
Tableofcontents
Acknowledgements.................................................................................................. iv
Abbreviationsandsymbols..................................................................................... vi
1 Introduction ........................................................................................................ 1
2 Objectives ........................................................................................................... 4
2.1. Generalobjectives .................................................................................................................. 4
2.2. Spatiallevelsofstructureconsideredinthestudy ............................................................. 6
2.3. Reviewoftheliterature........................................................................................................... 7
2.3.1. Radial
within7tree
variations
in
wood
anatomy
and
hydraulic
properties .......................... 7
2.3.2. Influence
of
structure
on
whole7tree
water
use............................................................... 13
2.3.3. Effects
of
stand
structure
on
canopy
transpiration
and
conductance ............................. 14
2.4. Hypotheses............................................................................................................................ 16
3 Studysites ........................................................................................................ 18
3.1. Steigerwald ............................................................................................................................ 18
3.2. Fichtelgebirge........................................................................................................................ 21
3.3. Sitecharacteristics ............................................................................................................... 22
4 Methods............................................................................................................. 25
4.1. Measurementsofsapflowwiththethermaldissipationtechnique ................................. 25
4.1.1. Principles
and
conversions............................................................................................. 25
4.1.2. Probe
design .................................................................................................................. 29
4.1.3. Field
installations ............................................................................................................ 29
4.1.4. Sample
trees .................................................................................................................. 30
4.1.5. Accuracy
and
errors ....................................................................................................... 33
4.2. Treeandstandbiometry....................................................................................................... 33
4.3. Sapwoodarea........................................................................................................................ 34ii
4.4. Leafareaindexofthecanopy.............................................................................................. 38
4.4.1. Direct
estimates
of
LAI,
allometric
relationships ............................................................. 38
4.4.2. Semi7direct
estimates
of
LAI,
leaf
area
per
unit
dry
mass .............................................. 39
4.4.3. Indirect
estimates
of
LAI ................................................................................................. 40
4.5. Meteorologicalandsoilmeasurements .............................................................................. 41
5 Results............................................................................................................... 44
5.1. Structuraldriversofcanopytranspiration.......................................................................... 44
5.1.1. Sapwood
area................................................................................................................. 44
5.1.2. Stand
structure ............................................................................................................... 49
5.1.3. Leaf
area
index
and
related
variables
of
tree
and
stand
structure.................................. 53
5.1.3.1. Leafareaperunitdrymass…………………………………………………………...……53
5.1.3.2. Leafareaindex………………………………...…………………………………………….54
5.1.3.3. Leafareatosapwoodarearelationship……………..…………………………………...57
5.2. Atmosphericandsoilconditionsduringtheinvestigatedyears...................................... 60
5.2.1. Steigerwald7sites
Steinkreuz
and
Großebene ............................................................... 60
5.2.2.

Fichtelgebirge7site
Farrenleite ....................................................................................... 70
5.3. Radialwithin4treevariationofxylemsapflowdensityJ .................................................. 75s
5.4. Whole4treewateruseQofFagussylvaticaandQuercuspetraea................................... 93t
5.5. Standwateruse:Canopytranspirationandcanopyconductance................................. 100
6 Discussion ...................................................................................................... 127
6.1. Structuraldriversofcanopytranspiration........................................................................ 127
6.2. XylemsapflowdensityJ ................................................................................................... 134s
6.2.1. Radial
patterns
of
sap
flow
density
J
in
Fagussylvatica.............................................. 134s
6.2.2. Sap
flow
density
J
in
Quercuspetraea ........................................................................ 138s
6.2.3. General
radial
pattern
of
J ........................................................................................... 140s
6.2.4. Effects
of
soil
conditions,
and
seasonal
trends
in
general,
on
radial
patterns
of
J
ins
Fagussylvatica.......................................................................................................................... 143iii
6.3. Whole4treewateruseQ...................................................................................................... 147t
6.3.1. Q
of
European
beech................................................................................................... 147t
6.3.2. Q
of
sessile
oak ........................................................................................................... 151t
6.4. CanopytranspirationE andcanopyconductanceg ..................................................... 157c c
6.4.1. Structural
controls
on
E
and
g .................................................................................... 159c c
6.4.2. Comparison
of
beech
in
the
Steigerwald
and
the
Fichtelgebirge.................................. 166
6.4.3. Comparison
of
beech
and
oak
in
mixed
stands
in
the
Steigerwald .............................. 169
6.4.4. Variation
of
E
of
beech
and
oak
across
Central
Europe.............................................. 176c
7 Conclusions.................................................................................................... 182
7.1. Reviewofhypotheses......................................................................................................... 182
7.2. Futureperspectives ...............................................