Structural and nutritional differences between climbers and their supporting trees in a montane rainforest in South-Ecuador [Elektronische Ressource] / Jörg Salzer

Salzer

Informations

• Publié par: universitat_ulm
• Publié le: 01 janvier 2004
• Nombre de lectures: 19
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Structural and nutritional differences
between climbers and their supporting
trees in a montane rainforest
in South-Ecuador

Dissertation Thesis





Department of Systematic Botany and Ecology, University of Ulm


Dissertation zur Erlangung des Doktorgrades Dr. rer. nat
an der Fakultät für Naturwissenschaften der Universität Ulm










2004
Dipl.-Biol. Jörg Salzer


Amtierender Dekan: Prof. Dr. R. J. Behm

1. Gutachter: Prof. Dr. Marian Kazda
2. Gutachter: Prof. Dr. Elisabeth Kalko


Vorgelegt am 01.10.2003
Tag der Promotion: 05.02.2004

CONTENTS

Acknowledgments IV
Summary V
Zusammenfassung VII
Resumen IX
1. Introduction 1
2. Material and Methods 10
2.1. Geographical location of the research area 10
2.2. Climatic conditions 11
2.3. Geology, geomorphology and soils 12
2.4. Vegetation 13
2.5. The investigation plots 15
2.5.1. Soil properties and vegetation types 16
2.6. Sampling procedure and processing of the plant material 20
2.6.1. Measuring leaf area index (LAI) and canopy gap fraction (DIFN) 21
2.6.2. Measuring relative photon flux density (PFD ) 22 rel
2.6.3. Calculation of leaf area (LA) and leaf mass per unit area (LMA) 23
2.6.4. Kjeldahl digestion 24
2.6.5. Photometry of phosphorus 24
2.6.6. Atomic absorption spectrometry 25
2.6.7. Measurements of carbon content 25
2.7. Statistical interpretation 26
2.7.1. Description of the investigation plots 26
2.7.2. Control for associations between the two growth forms 26
2.7.3. Testing the differences between the two growth forms 26
2.7.4. Testing the differences between the investigation plots 27
2.7.5. Testing the influence of external factors on the plants 28
2.7.6. Grouping of all variables in a principal components analysis 28

3. Results 29
3.1. Environmental conditions on the investigated plots 29
3.2. Sampled specimens and the host/climber-relationship 34
3.2.1. Plant lists 34
3.2.2. Plant distribution among the plots 36
3.2.3. Associations between the two growth forms 37

3.3. The differences in structural and nutritional parameters 40
3.3.1. Differences between the growth forms 40
3.3.2. Differences between the investigated plots 43
3.3.3. Leaf parameter values of the investigated genera 49
3.4. Leaf parameters of the investigated genera 63
3.5. Synthesis of leaf parameters 69
3.5.1. Factor loadings of the PCA 69
3.5.2. Factor loadings according to the genera 71
3.6. Comparison of young and mature leaves 76
3.6.1. Collected leaf samples 76
3.6.2. Differences in LMA, N and N 77 mass area

4. Discussion 80
4.1. Plot selection 80
4.2. Associations between climbers and host plants 81
4.3. Differences in leaf structure and nutrient allocation 83
4.3.1. Reduction in leaf mass per unit area in the climbers 83
4.3.2. Leaf structure on different plots under changing light regimes 85
4.3.3. Nitrogen allocation and its role in photosynthesis 87
4.3.4. The other nutrients 93
4.3.5. The role of Aluminium 95
4.3.6. Classification derived by PCA 97
4.4. Comparison of young and mature leaves 98
4.5. Conclusions 102

5. Literature 104

Appendices A1
Appendix 1: Environmental conditions at the sample pairs A1
Appendix 2: Soil-pH and content of exchangeable element on the plots A3
Appendix 3: Complete dataset of all collected climber species A4
Appendix 4: Complete dataset of all collected supporter species A6
Appendix 5: Mature and young leaves dataset A8
Appendix 6: Mean leaf structure parameters A9
Appendix 7: Mean leaf element contents A9
Appendix 8: Mean leaf structure parameters among all plots A10
Appendix 9: Mean leaf element contents among all plots A11
Acknowledgements IV
ACKNOWLEDGEMENTS
I want to express my acknowledgements to all who helped me with my work during the
past four years.
Firstly, I want to thank Prof. Dr. Marian Kazda for giving me the opportunity to conduct
my studies in several tropical countries, for guidance in every critical phase, and for the
free and trusty atmosphere he provided me in the Department of Systematic Botany and
Ecology. Not to forget his financial support during the whole time.
Secondly, I want to express my thanks to the co-referent Prof. Dr. Elisabeth Kalko, as she
showed so much interest in my work.
Without Prof. Dr. Sigrid Liede from the University of Bayreuth this work would not have
been possible. She asked me to help one of her PhD students in Ecuador and gave me
also the possibility to perform my own scientific program there. The study was included in
and partly financed by the DFG projects LI 496/11-1 and LI 496/11-2.
Research permit was given by the Instituto Ecuadoriano Forestal de Areas Naturales y
Vida Silvestre (INEFAN), and logistic help came from the Fundación Cinetífica San
Francisco (FCSF). Scientific counterpart in Ecuador was Ing. Zhoffre Aguirre.
I also want to thank Patricia Brtnik for translating the summary into spanish, Graciela
Hinze for her final reviews on the “resumen”, Dr. Iris Schmid, Philipp von Wrangell, Norbert
Gäng, Kordula Heinen and Gregoire Hummel for their ideas during the past years, Christel
Necker for her outstanding help in the laboratory, Steffen Matezki for determination of
most samples, and a long list of other people for their friendship and support – hopefully
they all know that they are mentioned.
Special thanks go out to Rita Schneider. She gave me not only substantial comments on
the manuscript, but also amounts of motivation and a place of peacefulness for my
mind in hard phases during the past months.
Finally, I want to mention my parents. They enabled me always to follow my way and
gave me all the support I needed so much. I just hope that my mother can see how
everything now has come to a great end. Summary V
SUMMARY
Climbing plants, like lianas, vines or root climbers, can be the dominating growth form
on several sites not only in tropical forests but also in other climatic zones. Climbers from a
wide range of plant families can be found especially on forest edges and treefall gaps.
The uneven distribution of this growth form was well investigated in the past years and
different reasons for that patchiness, like light demand, support quality and nutrient or
water availability were mentioned but not fully understood. Further research upon the
relationships between external parameters and climber abundance is necessary as
different types of mostly negative effects on the host trees were reported in many studies.
Knowledge about the climbers ecophysiology is mainly limited on transpiration and water
transport, but other physiological mechanisms that also determine the competitiveness of
a climbing plant and thereby its abundance are still poorly understood. The climbers fast
growth requires fast adaptability to changes in their surrounding conditions, such as
effective biochemical mechanisms within the plant, combined with low growth-cost and
high nutrient content. Former studies already indicated a good assignment of nitrogen
towards light harvesting under shade by low leaf mass per unit area (LMA) in the leaves of
climbers, accompanied by high leaf nitrogen contents. Aim of this study was to improve
the knowledge about the mechanisms that lead to different patterns in climber
abundance. Therefore basic data in high resolution were inquired about the nutritional
status of climber leaves compared with their supporting hosts along different
environmental conditions.
The study was performed in a primary montane rainforest in South-Ecuador along an
altitudinal gradient between 1930 m a.s.l. and 2700 m a.s.l., covering a wide range of
different forest types. On each of the 8 investigation plots 10 pairs of climbers and
supporting host plants were selected. Stand characteristics were investigated by
measuring LAI, DIFN and PFD below each sample pair and directly above them. The rel
single plots distinguished well in their crown closure and light availability, giving so the
possibility to achieve high resolution data about