Abbadie / Gignoux / Roux Lamto

Structure, Functioning, and Dynamics of a Savanna Ecosystem
2006
ISBN: 978-0-387-33857-6
Verlag: Springer US
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 179, 415 Seiten

Reihe: Ecological Studies

Synthesizing 40 years of ongoing ecological research, this book examines the structure, function, and dynamics of the Lamto humid savanna. From the history of the Lamto ecology station, to an overview of enivronmental conditions of the site, and examining the integrative view of energy and nutrient fluxes relative to the dynamics of the region's vegetation, this exacting work is as unique and treasured as Lamto itself.

Autoren/Hrsg.

Abbadie, Luc

Gignoux, Jacques

Roux, Xavier

Lepage, Michel

Gignoux, Jaques

Inhaltsverzeichnis

1;Preface;6
2;Contents;8
3;Contributors;18
4;1 History of the Lamto Ecology Station and Ecological Studies at Lamto;21
4.1;1.1 Origin and installation of the station;21
4.2;1.2 The scientific programs that sustained the station from 1962;26
4.3;1.3 The current programs: 2000 to present;28
4.4;1.4 Conclusion: Forty years of scientific production;29
4.5;References;29
5;The Environment;33
5.1;2 Geology, Landform, and Soils;34
5.1.1;2.1 Geology;34
5.1.2;2.2 Landform;34
5.1.3;2.3 Soils;36
5.1.4;References;42
5.2;3 Climate;44
5.2.1;3.1 Introduction;44
5.2.2;3.2 The Lamto climate in the context of the West African climates;44
5.2.3;3.3 The Lamto Geophysical Station: Forty years of routine climatic observations;46
5.2.4;3.4 Seasonal course of climatic parameters;48
5.2.5;3.5 Interannual variability and temporal trends;56
5.2.6;3.6 Conclusion;59
5.2.7;Acknowledgments;60
5.2.8;References;60
5.3;4 Environmental Constraints on Living Organisms;64
5.3.1;4.1 Introduction;64
5.3.2;4.2 Soil water;65
5.3.3;4.3 Soil nutrients;67
5.3.4;4.4 Light;69
5.3.5;4.5 Fire;70
5.3.6;4.6 Herbivory;75
5.3.7;4.7 Conclusion;76
5.3.8;References;76
5.4;5 Vegetation;81
5.4.1;5.1 Introduction;81
5.4.2;5.2 Main savanna types;81
5.4.3;5.3 Structure of the vegetation;82
5.4.4;5.4 Life-Forms;87
5.4.5;5.5 Phenological cycles;89
5.4.6;5.6 Conclusion;90
5.4.7;Acknowledgments;90
5.4.8;References;91
6;Structure and Functioning of Plant Cover;93
6.1;6 Soil-Plant-Atmosphere Exchanges;94
6.1.1;6.1 Introduction;94
6.1.2;6.2 Overview of the 1991 to 1994 field campaign;95
6.1.3;6.3 Savanna radiation budget and spectral signatures;97
6.1.4;6.4 Energy budget;103
6.1.5;6.5 Water balance and plant water status;109
6.1.6;6.6 CO2 exchanges and leaf conductance;116
6.1.7;6.7 NO, NO2, and O3 exchanges;121
6.1.8;6.8 Conclusion;123
6.1.9;Acknowledgments;124
6.1.10;References;125
6.2;7 Biomass Cycle and Primary Production;131
6.2.1;7.1 Introduction;131
6.2.2;7.2 The aboveground phytomass cycle;131
6.2.3;7.3 The belowground phytomass cycle;140
6.2.4;7.4 Primary production of Lamto savannas;143
6.2.5;7.5 Plant allocation strategies: What can be inferred from phytomass measurements?;150
6.2.6;7.6 Discussion: Toward an integrative approach of primary production and allocation;151
6.2.7;References;152
6.3;8 Tree/Grass Interactions;154
6.3.1;8.1 Introduction;154
6.3.2;8.2 Trees alter the understory grass environment;155
6.3.3;8.3 Trees and grasses share the same soil resources;161
6.3.4;8.4 Trees alter grass functioning and production;166
6.3.5;8.5 Conclusion;169
6.3.6;References;172
6.4;9 Modeling the Relationships between Vegetation Structure and Functioning, and Modeling Savanna Functioning from Plot to Region;177
6.4.1;9.1 Introduction;177
6.4.2;9.2 Models previously developed for predicting the functioning of Lamto savannas;178
6.4.3;9.3 TREEGRASS: A 3D model for simulating structure- functioning relationships in savanna ecosystems;179
6.4.4;9.4 Modeling the functioning of savannas at large scales;187
6.4.5;9.5 Conclusion;194
6.4.6;Acknowledgments;195
6.4.7;References;195
6.5;10 Modification of the Savanna Functioning by Herbivores;198
6.5.1;10.1 Introduction;198
6.5.2;10.2 Herbivore densities, biomasses, and green grass consumption rate in Lamto savannas;198
6.5.3;10.3 Field studies of grazing effect on the savanna functioning;202
6.5.4;10.4 Modeling approaches for understanding grazing effect on the savanna functioning;205
6.5.5;10.5 Conclusion;207
6.5.6;References;209
7;Carbon Cycle and Soil Organic Matter Dynamics;212
7.1;11 Origin, Distribution, and Composition of Soil Organic Matter;213
7.1.1;11.1 Introduction;213
7.1.2;11.2 The inputs of organic matter to soil;214
7.1.3;11.3 Soil organic matter distribution;215
7.1.4;11.4 Chemical composition of soil organic matter;219
7.1.5;11.5 Conclusion;226
7.1.6;References;227
7.2;12 Soil Carbon and Organic Matter Dynamics;231
7.2.1;12.1 Soil micro-organisms;231
7.2.2;12.2 The limitation of soil microbial activity by the supply of organic and mineral compounds;232
7.2.3;12.3 Plant litter decomposition;235
7.2.4;12.4 Soil organic matter mineralization and turnover;237
7.2.5;12.5 Modeling organic matter dynamic in Lamto soils;240
7.2.6;12.6 Conclusion;243
7.2.7;References;244
7.3;13 Perturbations of Soil Carbon Dynamics by Soil Fauna;247
7.3.1;13.1 Introduction;247
7.3.2;13.2 Earthworms and termites: Abundances and spheres of influence;248
7.3.3;13.3 Carbon distribution and storage;251
7.3.4;13.4 Carbon mineralization;253
7.3.5;13.5 Conclusion;257
7.3.6;References;258
8;The Nitrogen Cycle;264
8.1;14 Nitrogen Inputs to and Outputs from the Soil- Plant System;265
8.1.1;14.1 Introduction;265
8.1.2;14.2 Dry and wet depositions;265
8.1.3;14.3 Biological fixation of atmospheric dinitrogen;268
8.1.4;14.4 Grass cover leaching;273
8.1.5;14.5 Soil leaching;274
8.1.6;14.6 Denitrification;274
8.1.7;14.7 Nitrogen monoxide emission;276
8.1.8;14.8 Impact of fire on the nitrogen cycle;277
8.1.9;14.9 N fluxes associated to grass consumption by animals;280
8.1.10;14.10 Conclusion: The input-output balance of nitrogen;281
8.1.11;References;282
8.2;15 Nitrogen Dynamics in the Soil-Plant System;286
8.2.1;15.1 Introduction;286
8.2.2;15.2 Nitrogen dynamics in the shrub-tree layer;286
8.2.3;15.3 Nitrogen dynamics in the grass layer;287
8.2.4;15.4 Annual nitrogen requirements of grasses;291
8.2.5;15.5 Origin of grass nitrogen;292
8.2.6;15.6 The transformations of nitrogen in soil;295
8.2.7;15.7 Conclusion: The savanna, a system that retains nitrogen and mineral nutrients;303
8.2.8;References;305
8.3;16 Role of Soil Fauna in Nitrogen Cycling;307
8.3.1;16.1 Introduction;307
8.3.2;16.2 Nitrogen storage and throughput in soil macrofauna and associated structures;307
8.3.3;16.3 Impact of soil macrofauna on nitrogen dynamics and mineralization;311
8.3.4;16.4 Stimulation of plant growth by soil macrofauna;314
8.3.5;16.5 Conclusion;316
8.3.6;References;317
9;Plant Community Dynamics;320
9.1;17 Spatial Pattern, Dynamics, and Reproductive Biology of the Grass Community;321
9.1.1;17.1 Introduction;321
9.1.2;17.2 Structure of the grass layer;321
9.1.3;17.3 Dynamics of the grass layer;329
9.1.4;17.4 Reproduction system of Hyparrhenia diplandra and its population genetic structure as revealed by microsatellites;330
9.1.5;17.5 Conclusion;338
9.1.6;References;338
9.2;18 Structure, Long-Term Dynamics, and Demography of the Tree Community;341
9.2.1;18.1 Introduction;341
9.2.2;18.2 Factors influencing tree population dynamics;341
9.2.3;18.3 Spatial patterns of tree species;345
9.2.4;18.4 Tree population dynamics;352
9.2.5;18.5 Discussion: The interaction of demography and spatial patterns and its effect on savanna stability;364
9.2.6;References;366
9.3;19 Modeling Tree and Grass Dynamics: From Demographic to Spatially Explicit Models;371
9.3.1;19.1 Introduction;371
9.3.2;19.2 Persistence of savanna species under annual burning: Analysis through matrix population models;372
9.3.3;19.3 Spatialized demographic models;376
9.3.4;19.4 Conclusion: The dynamics of plant populations and spatial patterns;382
9.3.5;References;382
10;Toward an Integration of Savanna Structure, Functioning, and Dynamics;385
10.1;20 A Synthetic Overview of Lamto Savanna Ecology: Importance of Structure- Functioning- Dynamics Relationships;386
10.1.1;20.1 Introduction;386
10.1.2;20.2 Rationales for the structure-functioning-dynamics relationships approach;387
10.1.3;20.3 Structure-functioning relationships as a key to understanding the Lamto productivity paradox;389
10.1.4;20.4 Structure-dynamics relationships as a key to understanding changes in tree/ grass balance;391
10.1.5;20.5 Current approaches for studying tree functioning- dynamics relationships in Lamto savanna;391
10.1.6;20.6 Modeling as a synthesis tool for studying structure- functioning- dynamics relationships;392
10.1.7;20.7 Conclusion;394
10.1.8;References;395
10.2;21 Perspectives: From the Lamto Experience to Critical Issues for Savanna Ecology Research;398
10.2.1;21.1 Introduction;398
10.2.2;21.2 Scaling across time;400
10.2.3;21.3 Scaling across space: From plot to landscape and region;402
10.2.4;21.4 Scaling across system complexity;404
10.2.5;21.5 The whole picture: Modeling a spatially organized trophic web and its physical environment;406
10.2.6;21.6 Conclusion;408
10.2.7;References;408
11;Index;413