Dynamics of Bio-Elements in Soils Along a Land-Use Gradient in the Tropical Mountain Rain ...

159 Pages·2014·4.49 MB·English

Fakultät Umweltwissenschaften

Dynamics of Bio-Elements in Soils Along a Land-Use
Gradient in the Tropical Mountain Rain Forest of
Southern Ecuador

Dissertation for the academic degree
Doctor rerum naturalium (Dr. rer. nat.)

Presented by:
Ing. Juan Ignacio Burneo Valdivieso
Born 01/18/1975 in Loja-Ecuador

Reviewers:
Prof. Dr.habil. Franz Makeschin
Prof. Dr.habil. Reinhard Mosandl
Dr. habil Ute Hamer

Place and date of the public defense: Tharandt 13 December 2013
Erklärung des Promovenden

Die Übereinstimmung dieses Exemplars mit dem Original der Dissertation zum
Thema:

“Dynamics of Bio-Elements in Soils Along a Land-Use Gradient in the
Tropical Mountain Rain Forest of Southern Ecuador”

wird hiermit bestätigt.

Statement of the PhD Candidate

I hereby confirm that this copy is identical with the original dissertation titled:

“Dynamics of Bio-Elements in Soils Along a Land-Use Gradient in the
Tropical Mountain Rain Forest of Southern Ecuador”

Dresden, 04.03. 2013

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ACKNOWLEDGEMENTS

I would like to thank all those people who have provided professional and
academic support during the writing of this thesis. I would like to especially
thank Prof. Dr. habil. Franz Makeschin for providing expert guidance on the
research topic and for his academic support as my thesis supervisor.

I would also like to thank to all the members of the commission Prof. Dr. habil.
Jürgen Pretzsch, Prof. Dr. habil. Reinhard Mosandl, Dr. habil. Ute Hamer and
Prof. Dr. habil. Gert Dudel for their joint evaluation of this thesis.

In addition, I wish to thank Dr. Luis Miguel Romero, who established the
scientific collaboration linkages between Universidad Técnica Particular de Loja
(UTPL) and the Dresden University of Technology (TUD). This thesis project
would not have been possible without his extraordinary ability to network with
others.

I also wish to express my deep gratitude to the German Foundation of
Research (DFG) for their financial support.

Next, I wish to thank the staff at the Dresden University of Technology, Institute
of Soil Science and Site Ecology, especially the following individuals: Dr.
Thomas Klinger; Manuela Unger; Ina Klemm; Gerlind Mitschick, and Ruth
Rüger for helping me with laboratory work. Furthermore, I would like to thank
René Schulze for assisting with administration matters.

Also, I would like to express my special gratitude to Dr. Frank Haubrich, Dr.
Mengistu Abiy, for their expert advice and friendship. In addition, I wish to thank
Karin Potthast, Etienne Bahr, Alexander Tischer, Susanne Iost, Jörg Hilpmann
and Christian Böhm for their valuable friendship and scientific support.

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I would also like to take this opportunity to thank the governing bodies of the
Universidad Técnica Particular de Loja. Special thanks go to Dr. Juan Pablo
Suarez and the staff at the Agriculture and Food Sciences Department,
especially Dr. Pablo Acosta and Ing. Ruth Martinez. Moreover, I would like to
thank Ing. Pablo Ochoa who provided immense support during the final stages
of writing this thesis. By the same token, I wish to thank Paul Cahén for editing
this manuscript.

Finally, and most importantly, my special thanks go to my family. Thank you all
for your constant love and support!

To all and to the many others I have failed to mention.

Thank you
Juan Ignacio

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CONTENTS

ACKNOWLEDGEMENTS…………………………………………………………...IV
CONTENTS…. .................................................................................................. VI
LIST OF FIGURES ........................................................................................... IX
LIST OF TABLES ............................................................................................ XII
LIST OF ABBREVATIONS ............................................................................. XV
SUMMARY …………… ...................................................................................... 1

1. INTRODUCTION .......................................................................................... 13
1.1 General state of the arts ........................................................................ 13
1.2 Objectives .............................................................................................. 17
1.3 Hypotesis .............................................................................................. 18

2. RESEARCH AREA AND STUDY SITES ..................................................... 19
2.1 Location.................................................................................................. 19
2.2 General characteristic of the study sites ................................................ 24
2.2.1 Climate…..................................................................................……24
2.2.2 Geomorphology, geology and mineralogy …...........................……25
2.2.3 Soil…….....................................................................................……28
2.2.4 Vegetation ................................................................................……29
2.2.5 Human impact...........................................................................……31

2.3 Description of study sites ..................................................................... 32
2.3.1 Forest plots .................................................................................. 34
2.3.2 ECSF pastures plots .................................................................... 35
2.3.3 Sabanilla pastures plots ............................................................... 36
2.3.4 Succession plots .......................................................................... 37

3. MATERIAL AND METHODS ....................................................................... 39
3.1 Soil sampling and sample preparation………………………………...…...39
3.2 Physical, chemical and biological soil parameters ................................. 42
3.2.1 Dry matter and bulk density .......................................................... 42
3.2.2 Soil acidity .................................................................................... 43
3.2.3 Cation exchange capacity ............................................................ 44
VI
3.2.4 Available phosphorus .................................................................... 44
3.2.5 Soil organic carbon and total nitrogen .......................................... 45
3.2.6 Nutrient reserves .......................................................................... 45
3.2.7 Total elements ............................................................................. 46
3.2.8 Total KCl-extractable organic carbon and nitrogen fractions ....... 46
3.2.9 Turnover of soil organic carbon and nitrogen ................................ 47
3.2.10 Nitrogen mineralization potentials .............................................. 48
3.2.11 Available soil phosphorus .......................................................... 48
3.2.12 Microbial biomass carbon and nitrogen ..................................... 49
3.2.13 Soil respiration ........................................................................... 50
3.3 Data analysis .......................................................................................... 51

4. RESULTS AND DISCUSSION .................................................................... 52
4.1 Soil pH, echangeable cations and base saturation ............................... 52
4.2 Soil organic carbon and total nitrogen concetrations ............................. 57
4.3 Soil organic carbon : total nitrogen ratio ................................................. 61
4.4 Total and available phosphorus concentrations .................................... 63
4.5 Soil Organic Carbon and total nitrogen stocks ....................................... 66
4.6 Total and available phosphorus socks .................................................. 71
4.7 Exchangeable base cations stocks ....................................................... 77
4.8 Basal respiration ................................................................................... 83
4.9 Microbial biomass carbon ...................................................................... 86
4.10 Microbial biomass nitrogen .................................................................. 88
4.11 Ratio of microbial biomass carbon to soil organic carbon .................... 90
4.12 Net nitrogen mineralization .................................................................. 92
4.13 Discriminant Analysis ......................................................................... 94

5.CONCLUSION ............................................................................................. 98
6. BIBLIOGRAPHY……………………………………………………………….. 103
7. APPENDIX………. ..................................................................................... 131
8. CURRICULUM VITAE………………………………………………………….140.

VII
VIII
LIST OF FIGURES

Figure 1.1 Land-Use Gradient in the Tropical Mountain Rain Forest of
Southern Ecuador. ........................................................................ 18
Figure 2.1 Map of Loja and Zamora provinces, the site of our study ............. 19
Figure 2.2 Protected areas of Ecuador .......................................................... 20
Figure 2.3 Podocarpus National Park ............................................................. 21
Figure 2.4 Locations of the study area in Ecuador ......................................... 22
Figure 2.5 Overview of the research area ...................................................... 23
Figure 2.6 Aereal view of the San Francisco Scientific Satation .................... 24
Figure 2.7 Geomorphological and geological regions of Ecuador ................... 25
Figure 2.8 Geology of the research area ........................................................ 26
Figure 2.9 Typical rocks of the Chiguinda unit ................................................ 27
Figure 2.10 Three major soil groups of the study area .................................... 28
Figure 2.11 The vegetation of the forest,pastures and succession sites ........ 30
Figure 2.12 Arial photo of the location of the study area ................................ 33
Figure 2.13 Distribution of the plots in the study area ..................................... 34
Figure 2.14 Overview of the forest sites ........................................................ 35
Figure 2.15 Overview of the ECSF pastures sites ......................................... 36
Figure 2.16 Overview of the Sabanilla pastures sites .................................... 37
Figure 2.17 Overview of the succession fallow sites ..................................... 38
Figure 2.18 Overview of the Chamusquin hill succession fallow site ............. 38

Figure 3.1 Soil sampling organic layers and mineral soil ............................... 40
Figure 3.2 Preparation of samples and parameters to be determined ........... 41

Figure 4.1 Median and range of pH values in organic layer and mineral top
[H2O]
soils for all studied sites ............................................................... 53
Figure 4.2 Median and range of the effective cations exchangeable capacity in
organic layer and mineral top soils for all studied sites. (appedix
1)................ ................................................................................. 132
Figure 4.3 Median and range of the base saturation in organic layer and
mineral top soils for all studied sites ............................................ 56
Figure 4.4 Median and range of the soil organic carbon concentrations in
organic layer and mineral top soils for all studied sites ............... 58
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Figure 4.5 Median and range of the total nitrogen concentrations in organic
layer and mineral top soils for all studied sites ............................. 60
Figure 4.6 Median and range of the SOC: TN ratio in organic layer and mineral
top soils for all studied sites ......................................................... 62
Figure 4.7 Median and range of the total phosphorus concentrations in organic
layer and mineral top soils for all studied sites ............................. 64
Figure 4.8 Median and range of the available phosphorus concentrations in
organic layer and mineral top soils for all studied sites ................ 65
Figure 4.9 Median and range of the organic carbon stocks in organic layer and
mineral top soils for all studied sites .............................................. 67
Figure 4.10 Median and range of the nitrogen stocks in organic layer and
mineral top soils for all studied sites ............................................. 69
Figure 4.11 Median and range of total phosphorus stocks in organic layer and
mineral top soils for all studied sites ............................................. 72
Figure 4.12 Median and range of the available phosphorus stocks in organic
layer and mineral top soils for all studied sites ............................. 74
Figure 4.13 Average of available and total phosphorus stocks in (a) organic
layer and (b) mineral top soils for all studied sites ....................... 76
Figure 4.14 Median and range of exchangeable potassium CEC K stocks in
organic layer and mineral top soils for all studied sites (appendix 2)
…………………………………………………………..…………….133
Figure 4.15 Average of the CEC Ca and total Ca stocks in (a) organic layer and
(b) mineral top soils for all studied sites ....................................... 79
Figure 4.16 Average of exchangeable potassium CEC K and total potassium K
stocks in (a) organic layer and (b) mineral top soils for all studied
sites .............................................................................................. 81
Figure 4.17 Average of the CEC Mg and total Mg stocks in (a) organic layer
and (b) mineral top soils for all studied sites ................................ 83
Figure 4.18 Cumulated basal respiration ....................................................... 84
Figure 4.19 Microbial biomass carbon in organic layer and mineral top soils for
all studied sites ............................................................................ 87
Figure 4.20 Microbial biomass nitrogen in organic layer and mineral top soils for
all studied sites ............................................................................. 89
Figure 4.21 Microbial biomass carbon to soil organic carbon ratio
……………………………………………………………..…………… 91
Figure 4.22 Discriminant analysis (0-10 cm) ................................................... 96
Figure 4.23 Discriminant analysis (10-20 cm) (appendix 3) ......................... 136
Figure 4.24 Discriminant analysis (20-30 cm) (appendix 4) ......................... 138
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