Landscape Function and Disturbance in Arctic Tundra

446 Pages·1996·12.01 MB·English

by  J. F. Reynolds

Ecological Studies, Vol. 120
Analysis and Synthesis
Edited by
G. Heldmaier, Marburg, FRG
o.
L. Lange, Wiirzburg, FRG
H. A. Mooney, Stanford, USA
U. Sommer, Kiel, FRG
Ecological Studies
Vo lumes published since 1990 are listed at the end of this book.
Springer-Verlag
Berlin
Heidelberg
GmbH
James F. Reynolds John D. Tenhunen (Eds.)
Landscape Function
and Disturbance
in Arctic Tundra
With 109 Figures, 11 in color
and 47 Tables
Springer
Professor Dr. JAMES F. REYNOLDS
Duke University
Department of Botany
Phytotron Building
Box 90340
Durham, NC 27708
USA
Professor Dr. JOHN D. TENHUNEN
Universitat Bayreuth
Lehrstuhl fur Pftanzenokologie II
Bayreuth Institute for Terrestrial Ecosystem Research (BITOK)
D-9S440 Bayreuth
Germany
ISBN 978-3-662-01147-8 ISBN 978-3-662-01145-4 (eBook)
DOI 10.1007/978-3-662-01145-4
Library of Congress Cataloging-in-Publication Data
Landscape function and disturbance in arctic tundra / james F.
Reynolds, john D. Tenhunen (eds.).
p. cm. - (Ecological studies: v. 120)
Includes bibliographical references and index.
ISBN 978-3-662-01 147-8
1. Tundra ecology-Alaska-North Slope. 2. Landscape ecology-Alaska-North Slope.
3. Man-Influence on nature-Alaska-North Slope. 4. Tundra ecology-Arctic regions-Math
ematical models. 5. Landscape ecology-Arctic regions-Mathematical models. 6. Man-Influ
ence on nature-Arctic regions-Mathematical models. I. Reynolds. james F., 1946- ,
II. Tenhunen, john D., 1946- . III. Series.
QHI05.A4L36 1996
574.5'2644'097987-dc20
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© Springer-Verlag Berlin Heidelberg 1996
Originally published by Springer-Verlag Berlin Heidelberg in 1996
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Foreword
The plants dominating arctic tundra differ in a fundamental way from almost
all other plants on earth. They can carry on metabolic and reproductive proc
esses during the short, cold growing seasons of the far North at air and soil
temperatures only slightly above or even below oDe. These cold-adapted plants
are mostly herbaceous perennials or dwarf shrubs that form a mosaic of com
munities that are subject to large fluctuations in their physical environment,
both atmospheric and edaphic. These once pristine and relatively isolated
ecosystems are now subject to considerable disturbance, due mostly to in
creasing human populations and their use of off-road vehicles and industrial
equipment.
Arctic tundra is underlain with permafrost, which is as deep as 600 m in
places. It has been permanently frozen for thousands of years. Embedded in it
are ice wedges and lenses in polygonal patterns that characterize much of the
tundra. The permafrost is fundamental to arctic tundra ecosystems-it is
the "glue" that holds these ecosystems together. During the short summers,
the "active" soil layer above the permafrast table thaws briefly to depths of
ca. 20-75 cm and allows root penetration, growth, and nutrient uptake by
the tundra vegetation. Without the complementary interactions between
permafrost and tundra vegetation, thermokarst, or melting of the ground ice
followed by erosion and massive disturbance, would result in transport
of the materials sequestered in these ecosystems via the streams to the
ocean.
Since more than 25% of the earth's soil carbon is stored in arctic and
subarctic permafrost soils, irreversible thermokarsting would release large
amounts of carbon dioxide and methane into the atmosphere. Such posi
tive feedback to the atmosphere would stimulate additional temperature
increase, resulting in further loss of ecosystem stability. The release of
nutrients that have been frozen and dormant for so long in upland tundra
soils would stimulate production in river and lake ecosystems downstream,
where nutrients have been limiting for centuries or even millennia. If upland
ecosystems begin to disappear with the thermokarst, as happened within
only 11 years to the Voth Tundra near Barrow, we would face a situation
of considerable overall resource loss and environmental impact. If the
insulation to permafrost provided by tundra vegetation is damaged or de
stroyed by any disturbance, the underlying permafrost is doomed, as is the
tundra.
VI Foreword
This volume, which presents research from the US Department of Energy's
R4D project on disturbance in arctic ecosystems, is a welcome and thorough
contribution to arctic science. It clearly lays out many of the linkages control
ling ecosystem development that are shifted under disturbance regimes. This
large, multidisciplinary study was based at the Imnavait Creek watershed near
Toolik Lake, ca. 250 km south of Prudhoe Bay on the North Slope of Alaska,
and was a product of an important US National Research Council Committee
Report of 1982. Much of the research presented here was undreamed of 20
years ago when several of the chapter authors and I camped on this watershed
in an unusually cold July to formulate research priorities. Often, with snow
falling at dawn, we would be awakened by Bob White's bagpipes to enjoy Al
Johnson's and Skip Walker's pancakes and coffee and another fine day of field
work.
This volume suggests approaches for ecosystem management that are a
result of the close integration between fieldwork and computer modeling. The
groups working in specific disciplines have provided process summaries that
extend our knowledge of the tundra, while the modeling-as well as the overall
framework of the book-demonstrate the new promise of integrated land
scape approaches for creating management tools. It is essential that we con
tinue in the direction of the research described here, to build our capacity
to understand the dimensions of ecosystem impacts that may result due to
climate change or man's interference with natural ecosystem behavior. The
lessons from R4D as summarized here provide a unique opportunity for truly
joining ecosystem science with land and resource management in the Arctic
now and in the future.
Winter 1995 W.D. Billings
Department of Botany
Duke University
Contents
I Introduction ...................................... . 1
1 Ecosystem Response, Resistance, Resilience, and Recovery
in Arctic Landscapes: Introduction
J. F. REYNOLDS and J. D. TENHUNEN .................. . 3
1.1 Introduction ....................................... 3
1.2 NRC Committee Report ........ . . . . . . . . . . . . . . . . . . . . . . 6
1.3 The R4D Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.1 Objectives and Conceptual Framework ................. 8
1.3.2 Program Implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3.3 Landscape Function ................................. 12
1.4 Summary .......................................... 14
References .................................................. 16
2 Integrated Ecosystem Research in Northern Alaska,
1947-1994
G. R. SHAVER ...................................... . 19
2.1 Introduction ...................................... . 19
2.2 Early Days at NARL ................................ . 19
2.3 The U. S. Tundra Biome Program ..................... . 21
2.4 The Meade River RATE Program .................... . 22
2.5 Eagle Creek and Eagle Summit ....................... . 23
2.6 The Arctic LTER Program at Toolik Lake .............. . 25
2.7 Other Studies In Alaska and Elsewhere ................ . 26
2.8 Summary and Prospects ............................ . 27
References ................................................. . 29
3 Disturbance and Recovery of Arctic Alaskan Vegetation
D. A. WALKER ..................................... . 35
3.1 Introduction ...................................... . 35
3.2 Disturbance and Recovery ........................... . 35
3.3 Typical Disturbance and Recovery Patterns ............. . 39
3.3.1 Small Disturbed Patches ............................ . 39
3.3.2 Contaminants ..................................... . 43
3.3.2.1 Hydrocarbon Spills ................................. . 43
VIII Contents
3.3.2.2 Seawater and Reserve-Pit Spills ....................... . 45
3.3.3 Fire .............................................. . 47
3.3.4 Transportation Corridors ............................ . 48
3.3.4.1 Bulldozed Tundra and Related Disturbances ........... . 48
3.3.4.2 Off-Road Vehicle Trails ............................. . 50
3.3.4.2.1 Summer Travel .................................... . 50
3.3.4.2.2 Winter Travel ...................................... . 52
3.3.4.3 Permanent Roads and Pads .......................... . 54
3.3.4.4 Gravel Mines ...................................... . 55
3.3.4.5 Native Species in Revegetation of Gravel Pads and Mines .. 56
3.3.4.6 Road Dust ......................................... . 58
3.3.4.7 Roadside Impoundments ............................ . 59
3.3.5 Cumulative Impacts ................................ . 61
3.4 Conclusions ....................................... . 62
References .................................................. 64
4 Terrain and Vegetation of the Imnavait Creek Watershed
D. A. WALKER and M. D. WALKER .................... . 73
4.1 Introduction ...................................... . 73
4.2 Terrain ........................................... . 73
4.2.1 Glacial Deposits ................................... . 74
4.2.2 Retransported Hillslope Deposits ..................... . 75
4.2.3 Colluvial Basin Deposits ............................. . 79
4.2.4 Floodplain Deposits ................................ . 79
4.3 Vegetation ........................................ . 79
4.3.1 Flora ............................................ . 79
4.3.2 Vegetation Types .................................. . 80
4.3.2.1 Lichen-Covered Rocks .............................. . 85
4.3.2.2 Dry Heath ........................................ . 85
4.3.2.2.1 Exposed Sites ...................................... . 88
4.3.2.2.2 Snowbeds ......................................... . 88
4.3.2.3 Tussock Tundra ................................... . 89
4.3.2.4 Riparian Areas .................................... . 90
4.3.2.5 Mires ............................................ . 92
4.3.2.6 Beaded Ponds ...................................... . 93
4.4 West-Facing Toposequence ........................... 93
4.5 Terrain Sensitivity to Disturbance ..................... 97
4.6 Conclusions .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Appendix A. List of Plants for Imnavait Creek, Alaska . . . . . . . . . . . . . 99
References .................................................. 106
5 Vegetation Structure and Aboveground Carbon
and Nutrient Pools in the Imnavait Creek Watershed
S. C. HAHN, S. F. OBERBAUER, R. GEBAUER, N. E. GRULKE,
O. L. LANGE, and J. D. TENHUNEN ..................... 109
Contents IX
5.1 Introduction ....................................... 109
5.2 Description of Vegetation ............................ 109
5.3 Sampling Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.3.1 Cover..... ...... ...... .... .. .... ...... ....... .. ... 112
5.3.2 Biomass and Nutrient Pools .......................... 112
5.4 Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
5.5 Aboveground Biomass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
5.5.1 Live Biomass ....................................... 114
5.5.2 Photosynthetic Biomass .............................. 116
5.5.3 Lichen Biomass ..................................... 117
5.5.4 Organic Litter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
5.5.5 Watershed Patterns ................................. 118
5.6 Nutrient Pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
5.6.1 Nand P in Heath Cryptogams ........................ 118
5.6.2 Nand P in Communities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
5.7 Discussion and Conclusions .......................... 124
References .................................................. 126
II Physical Environment, Hydrology, and Transport . . . . . . . . 129
6 Energy Balance and Hydrological Processes
in an Arctic Watershed
L. HINZMAN, D. L. KANE, C. S. BENSON, and K. R.
EVERETT .......................................... 131
6.1 Introduction ....................................... 131
6.2 Radiation and Thermal Regimes . . . . . . . . . . . . . . . . . . . . . . . 131
6.2.1 Surface Energy Balance .............................. 133
6.2.2 Snow Cover and Soil Thermal Regime .................. 13 7
6.3 Hydrological Processes .............................. 140
6.3.1 Snowmelt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
6.3.2 Plot and Basin Water Balance. . . . . . . . . . . . . . . . . . . . . . . . . 142
6.3.3 Runoff and Basin Discharge .......................... 143
6.3.4 Precipitation, Evaporation, and Evapotranspiration. . . . . . . 145
6.4 Energy Balance and Hydrology Models ................. 146
6.4.1 Simulation of the Thermal Regime. . . . . . . . . . . . . . . . . . . . . 146
6.4.2 Simulation of Snowmelt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
6.4.3 Simulation of Catchment Runoff. . . . . . . . . . . . . . . . . . . . . . . ISO
6.5 Conclusions ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
References .................................................. 152
7 Shortwave Reflectance Properties of Arctic Tundra
Landscapes
A. S. HOPE and D. A. STOW ........................... ISS
7.1 Introduction ....................................... ISS
7.2 Shortwave Reflectance Studies in Arctic Environments .... 156
x
Contents
7.2.1 Environmental Considerations ........................ 156
7.2.2 Radiometric Data ................................... 156
7.2.3 Image Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
7.3 Spectral Reflectance ................................. 157
7.3.1 Aboveground Biomass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
7.3.2 Vegetation Composition ............................. 158
7.3.3 Landscape Patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
7.3.4 Effects of Dust Deposition. . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
7.4 Albedo ............................................ 160
7.4.1 Undisturbed Tussock Tundra ......................... 160
7.4.2 Effects of Dust Deposition ............................ 161
7.5 Conclusions .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
References .................................................. 163
8 Isotopic Tracers for Investigating Hydrological Processes
L. W. COOPER, I. L. LARSEN, C. SOLIS, J. M. GREBMEIER,
C. R. OLSEN, D. K. SOLOMON, and R. B. COOK ........... 165
8.1 Introduction ....................................... 165
8.1.1 Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
8.1.2 Conservative vs Nonconservative Isotopes .............. 166
8.2 Nonconservative Tracers ............................. 167
8.3 Sulfur-35 .......................................... 167
8.4 Oxygen-18 ......................................... 168
8.4.1 Oxygen-18 Content of Snowpack. . . . . . . . . . . . . . . . . . . . . . . 169
8.4.2 Oxygen-18 Content of Imnavait Creek. . . . . . . . . . . . . . . . . . 169
8.4.3 Oxygen-18 Content of Soil Moisture ................... 172
8.4.4 Covariance of Oxygen-18 and Deuterium in Watershed
Compartments ..................................... 172
8.4.5 Covariance of Oxygen-18 and Deuterium in Plant Water. . . 174
8.5 Long-Lived Radioisotopes: Lead-210 and Cesium-137 ..... 174
8.5.1 Distribution of I37Cs on Tundra and in Lake Sediments. . . . 175
8.5.2 Cycling of I37Cs in Annual Berries. . . . . . . . . . . . . . . . . . . . . . 176
8.5.3 Distribution oPlOPb in Tundra ........................ 178
8.6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
References .................................................. 179
III Nutrient and Carbon Fluxes .......................... 183
9 Surface Water Chemistry and Hydrology
of a Small Arctic Drainage Basin
K. R. EVERETT, D. L. KANE, and L. D. HINZMAN 185
9.1 Introduction ....................................... 185
9.2 Watershed Instrumentation .......................... 185
9.3 Snowmelt Period ................................... 187
9.3.1 Snowmelt Hydrology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187