Butler / Malanson / Walsh The Changing Alpine Treeline

The Example of Glacier National Park, MT, USA
1. Auflage 2009
ISBN: 978-0-08-095709-8
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 224 Seiten

The alpine treeline ecotone (ATE) is an area of transition high on mountains where closed canopy forests from lower elevations give way to the open alpine tundra and rocky expanses above. Alpine tundra is an island biome and its ecotone with forest is subject to change, and like oceanic islands, alpine tundra is subject to invasion - or the upward advance of treeline. The invasion of tundra by trees will have consequences for the tundra biome as invasion does for other island flora and fauna. To examine the invasibility of tundra we take a plant's-eye-view, wherein the local conditions become extremely important. Among these local conditions, we find geomorphology to be exceptionally important. We concentrate on aspects of microtopography (and microgeomorphology) and microclimate because these are the factors that matter: from the plant's-eye-view, but we pay attention to multiple scales. At coarse scales, snow avalanches and debris flows are widespread and create 'disturbance treelines” whose elevation is well below those controlled by climate. At medium scales, turf-banked terraces create tread-and-riser topography that is a difficult landscape for a tree seedling to survive upon because of exposure to wind, dryness, and impenetrable surfaces. At fine scales, turf exfoliation of the fronts of turf-banked risers, and boulders, offer microsites where tree seedlings may find shelter and are able to gain a foothold in the alpine tundra; conversely, however, surfaces of needle-ice pans and frost heaving associated with miniature patterned ground production are associated with sites inimical to seedling establishment or survival. We explicitly consider how local scale processes propagate across scales into landscape patterns.
The objective of this book is to examine the controls on change at alpine treeline. All the papers are focused on work done in Glacier National Park, Montana, USA. Although any one place is limiting, we are able to examine the alpine treeline here in some detail - and an advantage is that the treeline ecotone in Glacier National Park is quite variable in itself due to the underlying variability in geomorphology at multiple scales.
This book will provide insights into an important ecological phenomenon with a distinctly geomorphic perspective. The editors collectively have over 100 years of experience in working in geomorphology, biogeography, and ecology. They also have each worked on research in Glacier National Park for several decades. The book will be a reference for a variety of professionals and students, both graduate and undergraduate, with interests in Physical Geography, Geomorphology, Ecology, and Environmental Science. Because of the importance of the alpine treeline ecotone for recreation and aesthetic interests in mountain environments, wildland and park managers will also use this book.
* Subject matter: geomorphology at alpine treeline
* Expertise of contributors: each editor brings over 25 years of experience in studies of ecotones and geomorphology, and collectively over 100 years of experience in Glacier National Park
* Changing alpine treeline examines climate change

Autoren/Hrsg.

Butler, David R.

Malanson, George P.

Walsh, Stephen J.

Fagre, Daniel B.

Inhaltsverzeichnis

1;Front Cover;1
2;The Changing Alpine Treeline: The Example of Glacier National Park, MT, USA;4
3;Copyright Page;5
4;Table of Contents;8
5;Editorial Foreword;14
6;Preface;16
7;Acknowledgments;18
8;List of Acronyms;20
9;List of Contributors;22
10;Chapter 1. Introduction: Understanding the Importance of Alpine Treeline Ecotones in Mountain Ecosystems;24
10.1;1. Introduction;24
10.2;2. Importance of High-Elevation Mountain Research;25
10.3;3. Recent Changes to the Alpine Areas of Glacier National Park;26
10.4;4. Factors Affecting the Alpine Treeline Ecotone;29
11;Chapter 2. Pattern–Process Relations in the Alpine and Subalpine Environments: A Remote Sensing and GIScience Perspective;34
11.1;1. Introduction;34
11.2;2. Study Area;35
11.2.1;2.1. General setting;35
11.2.2;2.2. Geographic areas of research emphasis;37
11.3;3. Background and Context;39
11.3.1;3.1. Remote sensing approaches;40
11.3.2;3.2. Field approaches;41
11.3.3;3.3. GIS representation;42
11.4;4. Data and Methods;43
11.4.1;4.1. Medium-grained remote sensing;43
11.4.2;4.2. High-resolution DEM creation;44
11.5;5. Selected Applications;47
11.5.1;5.1. Pixel versus object classification of vegetation;47
11.5.2;5.2. Linear mixture modeling;51
11.5.3;5.3. Pattern metrics;52
11.6;6. Conclusions;54
12;Chapter 3. Ecotone Dynamics: Invasibility of Alpine Tundra by Tree Species from the Subalpine Forest;58
12.1;1. Introduction;58
12.1.1;1.1. Plant’s eye view;59
12.2;2. Seeds to Seedlings in Open Tundra;60
12.2.1;2.1. Dispersal;61
12.2.2;2.2. Protected sites;63
12.2.3;2.3. Annual weather;66
12.3;3. Seedlings;66
12.3.1;3.1. Coarse scale climate;67
12.3.2;3.2. Endogenous climate modification;69
12.3.3;3.3. Microclimate;71
12.3.4;3.4. Soil;73
12.4;4. Tree or Krummholz Form;74
12.5;5. Facilitation or Inhibition?;77
12.5.1;5.1. Pattern and process;78
12.6;6. Conclusion;79
13;Chapter 4. Geomorphic Patterns and Processes at Alpine Treeline;86
13.1;1. Introduction;86
13.2;2. Coarse-Scale Processes;88
13.2.1;2.1. Snow avalanches as treeline disturbance agents;88
13.2.2;2.2. Debris flows as treeline disturbance agents;90
13.3;3. Medium-Scale Processes;91
13.3.1;3.1. Turf-banked terraces;92
13.3.2;3.2. Eolian processes at treeline;94
13.4;4. Fine-Scale Processes and Landforms;96
13.4.1;4.1. Turf exfoliation;96
13.4.2;4.2. Boulders;97
13.4.3;4.3. Needle-ice pans;99
13.4.4;4.4. Frost heaving and churning;102
13.5;5. Additional Comments on the Possible Role of Animals at Treeline;104
13.6;6. Conclusions;104
14;Chapter 5. Environmental Controls on Turf-Banked Terraces;108
14.1;1. Introduction;108
14.2;2. Background;109
14.3;3. Study Site;113
14.4;4. Methods;115
14.5;5. Results;120
14.6;6. Discussion;125
14.7;7. Conclusions;128
15;Chapter 6. Soils and Pedogenesis at Alpine Treeline;130
15.1;1. Introduction;130
15.1.1;1.1. Background;131
15.2;2. Field Data Collection;132
15.2.1;2.1. Soil pit data at Lee Ridge and White Calf Mountain;132
15.2.2;2.2. Soil penetrability and compression on Turf-banked terrace treads and risers;134
15.3;3. Results;137
15.3.1;3.1. Soil pit data from tree fingers and adjacent tundra;137
15.3.2;3.2. Effective soil depth and soil compaction data;138
15.4;4. Discussion and Conclusions;140
16;Chapter 7. Canopy Structure in the Krummholz and Patch Forest Zones;142
16.1;1. Introduction;143
16.2;2. Background and Context;144
16.2.1;2.1. Alpine treeline;144
16.2.2;2.2. Leaf area index;146
16.3;3. Study Area;147
16.3.1;3.1. Lee Ridge;148
16.3.2;3.2. Apikuni Cirque;149
16.3.3;3.3. Cataract Creek;149
16.3.4;3.4. Preston Park;150
16.3.5;3.5. Baring Basin;150
16.3.6;3.6. Scenic Point;150
16.3.7;3.7. East Flattop Mountain;150
16.4;4. Data and Methods;151
16.4.1;4.1. Field data collection;151
16.4.2;4.2. Digital elevation model and terrain analysis;151
16.4.3;4.3. Vector data sets;153
16.4.4;4.4. Data processing;153
16.5;5. Analysis;155
16.5.1;5.1. 3D visualization;156
16.5.2;5.2. Spatial analysis;156
16.5.3;5.3. Biophysical analysis;162
16.5.4;5.4. Topo-climatic variables;166
16.6;6. Results and Discussion;166
16.6.1;6.1. Internal canopy structure;167
16.6.2;6.2. Between patch structure;168
16.7;7. Conclusions;169
17;Chapter 8. A Markov Analysis of Tree Islands at Alpine Treeline;174
17.1;1. Introduction;174
17.2;2. Methods;177
17.2.1;2.1. Markov chain analysis;177
17.2.2;2.2. Embedded Markov chains;180
17.2.3;2.3. First-order Markov chains;180
17.3;3. Results;181
17.3.1;3.1. Spatial sequence of conifer establishment;181
17.3.2;3.2. Stability at treeline;181
17.4;4. Discussion;182
17.4.1;4.1. Establishment characteristics;183
17.4.2;4.2. Treeline stability;184
17.5;5. Conclusions;186
18;Chapter 9. Modeling Feedback Effects on Linear Patterns of Subalpine Forest Advancement;190
18.1;1. Introduction;190
18.1.1;1.1. Treeline patterns;191
18.1.2;1.2. Explanations of treeline pattern;192
18.1.3;1.3. Modeling treeline location and dynamics;193
18.2;2. Methods;195
18.2.1;2.1. FORSKA;195
18.2.2;2.2. Parameterization;195
18.2.3;2.3. Modifications;198
18.2.4;2.4. Site quality;199
18.2.5;2.5. Simulations;201
18.3;3. Results;203
18.4;4. Discussion;205
18.4.1;4.1. Gap models and treeline environments;205
18.4.2;4.2. Effects of light and mortality;206
18.5;5. Conclusions;208
18.6;Acknowledgments;210
19;Chapter 10. The Future of Treeline;214
19.1;References;217
20;Index;218