November 2008

Extent of the North American Boreal Zone

Dr. James Brandt jbrandt@nrcan.gc.ca Sir William Logan Building Ottawa CANADA

Introduction

Circumpolar boreal zone is one of the worlds largest and most important biogeoclimatic areas

Background

In the literature, there is large variation in the area of forests within circumpolar boreal zone

Maps are often low resolution little value for estimating area

Methodologies & terminologies of researchers have varied resulting in different opinions on limits of boreal zone in various regions

Language barriers literature written in several languages (Chinese, English, Finnish, French, Japanese, Mongolian, Norwegian, Swedish, Russian)

Opportunities

Geographic information systems (GIS) have improved our ability to produce spatially accurate maps

Technology is limited by accuracy & resolution of accessed spatial data

Recent studies within boreal zone and other recently developed spatial data sets provide new data that can be used in combination with a GIS to develop an improved North American boreal zone map

Objectives

Review North American literature pertaining to plant geography of boreal zone

Develop revised map of North American boreal zone and hemiboreal subzone using consistent criteria & most current information

Use GIS to compare & contrast existing maps of zone

Provide descriptive statistics on the area of the boreal zone and the hemiboreal subzone based on the new map

Source Maps

Maps of North Americas boreal zone and its forests were scanned, digitized, and converted to GIS shapefiles; several maps were available digitally

All shapefiles converted to same projection and datum

GIS used to view & compare boundaries of 32 maps of boreal zone

Vegetation Zones Defined

Arctic zone absence of trees, occurrence of continuous permafrost, and presence of tundra vegetation dominated by low-growing shrubs, herbaceous plants, mosses, and lichens (Walker et al. 2002)

Boreal zone the broad, circumpolar vegetation belt of high northern latitudes covered with forests and other wooded land consisting of cold-hardy trees primarily within the genera Abies, Larix, Picea, or Pinus but also Populus and Betula

Temperate zone dominance on most sites of tree species intolerant of extremely cold winter temperatures (warmer than 45oC) (includes hemiboreal subzone)

in continental situations, occupied primarily by grasslands, where their occurrence is dictated by moisture availability

North America

North America

Rowe (1972)

North America

Viereck & Little (1972)

Rowe (1972)

Viereck & Little (1972)

Rowe (1972)

North AmericaBoreal zone, hemiboreal subzone, alpine areas

Boreal zone

Viereck & Little (1972)

Rowe (1972)

North AmericaBoreal zone, hemiboreal subzone, alpine areas

Boreal zone

Hemiboreal subzone (Temperate zone)

Viereck & Little (1972)

Rowe (1972)

North AmericaBoreal zone, hemiboreal subzone, alpine areas

Boreal zone

Hemiboreal subzone (Temperate zone)

Alpine areas (within the Boreal zone and Hemiboreal subzone

North AmericaBoreal zone, hemiboreal subzone, alpine areas

Boreal zone

Hemiboreal subzone (Temperate zone)

BC Ministry of Forests

and Range, 2006

Marschner, 1974

Finley, 1976

Comer et al., 1995

Feilberg, 1984

Archibold &

Wilson, 1980

Payette, 1983

Timoney, 1988

Rowe, 1972

Saucier et al., 1998

Zoltai, 1975Shantz & Zon, 1936

Rowe, 1972

Natural Regions

Committee, 2006

Viereck &

Little, 1972

Bird, 1961

Oswald &

Senyk, 1980

North AmericaBoreal zone and hemiboreal subzone

Boreal zone

Hemiboreal subzone (Temperate zone)

North American TreelineFrom CAVM

Northeastern North America TreelineFrom CAVM

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Northeastern North America8 other approaches in chronological order

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Western Interior of North America10 other approaches

Areal Extent (in millions of ha)

Study

Boreal zone in

Canada

This paper 552

FAO (2006) 526

Olsen et al. (2001) 461

ESWG (1995) 582

EWG (1989) 556

Tuhkanen (1984) 557

Rowe (1972) 531

Semenova-Tyan-Shanskaya (1964) 511

Conclusions

The map of the North American boreal zone should be considered a refinement of the maps of Rowe (1972) and Viereck and Little (1972). The hemiboreal subzone, while mapped, is considered part of the temperate zone.

These changes in the map of the boreal zone reflect an improvement in technology and data sets rather than a shift due to environmental or anthropogenic factors.

Thus, scientists, regulators, and environmental groups can use the map and the corresponding statistics of the North American boreal zone to create a common baseline or standard against which future changes in the North American boreal zone and the success of conservation efforts can be measured.

Questions?

Acknowledgements

C. van Eden graphic design

J.-P. Saucier, Qubecs Ministre des Ressources naturelles et Faune GIS data of Quebecs Ecological Land Classification hierarchy

J. Weber, R. Brett, M. Gartrell, and

M. Newman GIS work at NoFC

T. Scupien, USDA FS GIS data of original vegetation in Michigan,

Minnesota, and Wisconsin

T. Hogg, B. Meades, J. Volney, and the anonymous reviewers of Environmental Reviews for their contribution to improving the manuscript

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

North Central North America4 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Northwestern North America8 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Great Lakes Region of North America10 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches

Western Cordillera of North America8 other approaches