Restoring the Pacific Northwest: The Art and Science of Ecological Restoration in Cascadia
506
Restoring the Pacific Northwest: The Art and Science of Ecological Restoration in Cascadia
506eBook
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Overview
Product Details
| ISBN-13: | 9781610911030 |
|---|---|
| Publisher: | Island Press |
| Publication date: | 09/26/2012 |
| Series: | The Science and Practice of Ecological Restoration Series |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 506 |
| File size: | 25 MB |
| Note: | This product may take a few minutes to download. |
About the Author
Dean Apostol is a landscape architect, natural resource planner, writer, and teacher who lives and works on a small farm near Portland, Oregon.
Marcia Sinclair, writer, editor, and consultant, is outreach specialist for the Willamette Partnership. She lives near Portland, Oregon.
Read an Excerpt
Restoring the Pacific Northwest
The Art and Science of Ecological Restoration in Cascadia
By Dean Apostol, Marcia Sinclair
ISLAND PRESS
Copyright © 2006 Island PressAll rights reserved.
ISBN: 978-1-61091-103-0
CHAPTER 1
Northwest Environmental Geography and History
DEAN APOSTOL
It is not bragging to claim that the Pacific Northwest is one of the world's most spectacular regions. Our mountains and glaciers would make the Swiss envious, and our jagged, rocky coast washed by crashing ocean surf is the equal of New Zealand, Norway, or western Ireland. Our old- growth conifer forests have some of the world's tallest trees and highest levels of biomass. The vast sagebrush steppe is a land of national park- scale superlatives. One of the least populated places in North America, it boasts the deepest canyon (Hell's Canyon of the Snake River) and largest natural fault (Steens Mountain) on the continent.
Our human history and cultural development are equally impressive and fascinating. Northwest Indians attained a unique and very sophisticated level of art and culture that reflected the material abundance of the land and sea. The journals of Lewis and Clark reveal the land as it was before Euro-Americans set about changing it. Pioneers on the Oregon Trail bypassed nearly 3,000 miles of central continent to reach Oregon Country, rich in fish, farmland, and forest. Today's farmers continue to cultivate deep, rich alluvial Willamette Valley soils, reaping harvests of grain, fruit, and vegetables. The sparse soils of the Oregon Coast Range and eastern Washington produce some of the highest-quality wine grapes anywhere.
Much has been written about the geography and history of the Pacific Northwest, and this chapter can offer only a modest summary. As illustrated in Plate 1 in the color insert, Cascadia spans the middle to northerly temperate latitudes, from around 40 degrees south (northern California) to nearly 60 degrees north (the southern mainland of Alaska). Marine air over the northern Pacific Ocean fights a timeless war with continental air masses, each taking charge at different times of the year. West of the Cascade and Coastal mountain ranges, the Pacific usually has the upper hand, while to the east the drier continental system rules. Lands in the south, particularly the Siskiyou-Klamath Mountain subregion, are much drier than the north, especially in summer, when a blessed high-pressure system parks itself over the ocean off the Oregon coast. The climate is maritime in the north, increasingly Mediterranean in the south, and continental in the east, with a great number of intermediate zones and microclimates between them (Goble and Hirt 1999, Franklin and Dyrness 1973).
The Pacific Northwest is also shaped by three large geologic forces: tectonics, volcanoes, and glaciers. Ocean plates grind under the continent, shoving, melting, and lifting rock. The result is a geologically young land, formed of materials drawn from the ocean depths and reborn through volcanic action. Significant amounts of exotic terrain collided with the continent from great distances over a period of 200 million years and formed parts of the lands west of Idaho (Alt and Hyndman 1995). Generally the terrain in the east is older than that farther west. The rocks of the Klamath-Siskiyou Mountains in the southwestern part of the region are the exception, having arrived more than 200 million years ago, now jumbled into a chaotic heap (Trail 1998).
Elevation ranges are substantial, from sea level to more than 4,000 meters. Southeastern Alaska, the west coast of British Columbia, and the Olympic Peninsula include the wettest places in North America, whereas the sagebrush steppe, in the rain shadow of the Cascade Mountains, is characterized by arid plains. Diverse ecosystems are distributed across this terrain, responding to elevation, rainfall, underlying geology, soils, aspect, and cultural influences. An island mountain archipelago reaches south from Alaska, down the British Columbia coast, and through Puget Sound. Vancouver Island, at more than 32,000 square kilometers, is the largest island along North America's Pacific Coast. The Queen Charlotte Islands, or Haida Gwai, have been called the Canadian Galá-pagos, reflecting their remoteness from the main continent. Over the past 2 million years, successive advances and retreats of glaciers have also carved and shaped the landscape. The last retreat of the continental ice sheets was only some 12,000 years ago (the ice was 5,000 feet thick at the Washington-British Columbia border), and the Northwest remains a land with many glaciers.
Ecosystem Biogeography
Topographic complexity and proximity to the northern Pacific Ocean combine to create very diverse assemblages of plants and animals. The Northwest has tremendous landscape diversity over a fairly small area, a function of numerous mountain chains and quite variable precipitation, including some of the wettest and driest areas on the continent. Drive 200 miles in any direction from nearly any point in the region and you will experience significant ecosystem change, possibly more than anywhere else on the North American continent. Plant communities tend to run in north-south rather than east-west gradients, reflecting the orientation of major mountain ranges. West of the major mountains is the largest temperate rainforest in the world (Franklin and Dyrness 1973). In southeast Alaska, where the climate is cool and very wet even in summer, Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), and yellow cedar (Chamaecyparis nootkatensis) are the dominant overstory trees. Perched peat bogs, or muskegs, with lodgepole pine (Pinus contorta) are also increasingly common in the north (Pojar and MacKinnon 1994). Rivers and streams teem with salmon. Farther south, in British Columbia, western redcedar (Thuja plicata) becomes increasingly dominant, and Douglas fir (Pseudotsuga menziesii) occupies more inland sites. Farther south along the coast, summer air temperatures warm, and as a consequence dense fogs form. Redwoods (Sequoia sempervirons) become a key component of the forest. Prairies, or grass balds, increase in frequency on coastal headlands farther south as well, adding diversity to the extensive forest matrix (Franklin and Dyrness 1973; Chapter 5).
Inland valleys, particularly the Georgia Straight-Puget Trough of Washington and the Willamette Valley of Oregon, are in the rain shadow of coastal mountains and therefore are much drier, which has allowed them to support bunchgrass prairies and Garry oak (Quercus garryana) woodland ecosystems (Chapters 3 and 4). Farther east the mountains rise to heights well above the tree line, with rich meadows, huckleberry fields, and subalpine parklands forming below and around the many glaciers (Chapter 11). North of Mt. Rainier, the tree line drops lower and parklands become more extensive than in the south (Chapter 11). East of the mountains a second rain shadow, a characteristic of the north-south mountain orientation, causes the forests to quickly change from hemlock to fir to pine and eventually to open up onto the vast sagebrush steppe of the interior Northwest (Chapters 9 and 10).
This geography includes the most extensive network of salmon-bearing streams on the planet (Chapter 13). All the major mammals of the North American continent still find homes in the region: grizzlies, wolves, lynx, cougars, bison, moose, elk, and many more (Chapter 15). It is a rich and beautiful environment that continues to attract tourists and immigrants from around the world, even while holding its native born close by.
A Very Brief Environmental and Ecological History
Although there is some dispute over exact dates, the evidence clearly shows that humans have been part of the Pacific Northwest landscape for at least 10,000 years and probably longer. "Kennewick Man," whose remains were discovered along the Columbia River shore, has been dated at more than 8,000 years old (Burke Museum 2005). The last retreat of glaciers 12,000–20,000 years ago allowed development of forests over much of the western part of the region, although the composition and structure we are familiar with today settled into place much later (Schoonmaker et al. 1997, Goble and Hirt 1999). Retreat of the glaciers was followed by a warm, dry climate that favored the northward spread of oaks and the westward movement of Douglas fir. Sagebrush steppe vegetation reached much farther west than at present, all the way to the western end of the Fraser River Valley. Then the climate cooled and became wetter, favoring hemlock and cedar and resulting in shrinkage of the range of oaks. There is speculation, but not physical evidence, that this may be the time when Northwest Indian people developed fire management of prairies and oak woodlands in interior valleys, which allowed them to persist even after a cooling of the climate should have resulted in their overtake by forest.
The pattern and distribution of forests, oak woodlands, prairies, streams, steppe, and wetlands that Lewis and Clark traveled through in the early nineteenth century had been in place only for 4,000–5,000 years. Forests were part of an ever-shifting mosaic that responded to periods of drought and large wildfires (Agee 1993). Rivers flooded, changed course, and created dynamic riparian zones, sometimes with enormous log jams (Ecotrust 2002). But the basic distribution of major vegetation communities was fixed, with only small further shifts at the margins.
Indian people interacted with this pattern and affected it in many ways. Level terraces along rivers and estuaries were cleared and occupied as village sites. Northwest Indians were skilled woodworkers and harvested trees and planks for canoes, building materials, tools, and weapons. Brush was gathered for firewood, basketry, and other uses. Western redcedar (Thuja plicata) was the "tree of life," used for everything from roofing to baby diapers and menstrual pads. Most importantly, almost every major ecosystem type in the region was shaped in part by Indian fire (Boyd 2000). Prairies and oak and pine woodlands were burned on a frequent basis, with forests underburned less frequently. Small clearings were made to attract game animals, even in the far northern coastal areas. Huckleberry patches and travel corridors in the mountains were also burned. There is little question that all of this burning had a profound effect on regional ecosystems (Chapter 17).
Plants were gathered in great numbers. Some, such as camas, may have been transplanted deliberately and managed to increase abundance (Boyd 2000). Salmon was the main food source for people far into the interior of the Columbia Basin. Harvest techniques included construction of weirs to funnel fish into shallow areas where they could be trapped and harvested more easily.
Development of sea trading by captains Vancouver, Gray, and others, Lewis and Clark's journey, the development of the beaver trade, missionaries, and thousands of pioneers seeking new land initiated profound social and environmental changes in the region. Diseases such as measles and smallpox reduced Indian populations by as much as 90% in some areas, beginning in the late eighteenth century (Schoonmaker et al. 1997). This catastrophe probably disrupted burning cycles and caused abandonment of villages, contributing to the pioneer impression that the Northwest was only lightly populated or unsettled (Robbins 1997).
Widespread trapping of beavers by agents of Hudson's Bay Company, designed in part to create a "beaver desert" that would discourage competitors, had profound effects on streams and wetlands all across the region (Lichatowich 1999). Only recently have ecologists begun to appreciate the critical role beavers play in sustaining complex aquatic and riparian habitats. Farmers settled and plowed the most fertile prairie soils first, then quickly spread to oak woodlands and prairie margins. Forests were cleared, cities were platted and built at the heads of deepwater navigation, and dredging of the Willamette and other rivers converted highly complex, braided systems to simple channels that could accommodate large vessels. By 1895, an estimated 50% of the bottomland hardwood forests of the Willamette Valley had been converted to agriculture, and the riparian conifers were almost completely gone (Hulse et al. 2000). Dikes were built along estuaries and lowlands, with wetlands ditched and drained. Intensive logging began along streams and rivers in the lower mountain reaches. On smaller streams, such as those in the Oregon Coast Range, splash dams temporarily backed water up to corral logs, which were then dynamited, releasing a torrent downstream that tore out natural log jams and sluiced riverbeds down to bedrock (Ecotrust 2002).
Early Northwest Euro-American settlers, loggers, and town builders for the most part had little understanding and less regard for native ecosystems or native people. They saw the region as a vast wilderness and saw their job as taming it and bringing it to heel. Government surveyors laid out a straight-lined grid of townships, sections, and range, initially stopping only where the land was considered unsuitable for farming or town building. The few remaining Indians were herded off to remote reservations on land white people did not want, at least at first. Over time most of these lands were confiscated as well. Fish, particularly salmon, were harvested with no thought of sustaining them, and population declines were well documented by the late nineteenth century (Lichatowich 1999).
Indian and pioneer trails became muddy farm-to-market roads, some surfaced with planks. Plank roads were later straightened and finally paved. Logging moved deeper into the forests along temporary railroads, then migrated upslope as trucks became the preferred transportation mode. The U.S. Forest Service, first established as a guardian of watersheds, got into the logging business in a big way in the 1950s to help feed the postwar housing boom and make up for depleted private forests. Logging revenues were used to build a powerful agency. British Columbia forests, 90% of which are owned by the Crown, have followed a similar path, although they trailed a few decades behind the U.S. logging curve. Clearcutting, at first shunned by foresters trained in European methods and a timber industry interested only in the highest- value trees, became the preferred harvest technique. It proved to be more efficient than selective cutting and allowed quick reforestation with sun- loving Douglas fir, the fastest-growing and most valuable tree in the much of the region. East of the mountains in the pine woodlands Indian fire was stopped, natural fires suppressed, and selective logging of old- growth pine initiated. Shade-tolerant fir trees quickly occupied the ground and filled in, and at first foresters were delighted (Arno and Fiedler 2005; Chapter 9).
High mountain meadows were grazed by armies of sheep and herded great distances to market. Millions of cattle were let loose on the unfenced, previously lightly grazed sagebrush steppe, resulting in a severe loss of native bunchgrasses (Chapter 10). Invasive species, some brought in accidentally, others on purpose, hitched rides into the Northwest with the new settlers. Hundreds of large and small dams were built for hydropower and flood control. At first they were mainly in upper tributaries, but some were near tidal zones, such as the Elwha on the Olympic Peninsula (Lichatowich 1999).
Ecological losses have only recently begun to be tallied. Old-growth conifer forests west of the Cascades, the most studied ecosystem in the Northwest, now cover only 10–15% of the presettlement extent in Oregon and Washington, with higher amounts remaining in British Columbia and southeast Alaska (Chapter 6). Interior pine forests have all been degraded by fire suppression, grazing, and logging. Tens of thousands of miles of roads, most very poorly built, prone to failure, with fish-blocking culverts, are laced through forested mountains. Bunchgrass prairies west of the Cascades are down to a tiny fragile fraction of their original extent (Chapter 3). Oak woodlands, though still occupying roughly the same area, have been severely disrupted by fire suppression and grazing, their understory communities most highly affected (Chapter 4). Freshwater wetlands have been reduced by 50%, or even more in densely settled places such as the Willamette Valley, the Puget Sound, and along the Fraser River (Chapter 7). Tidal wetlands have been substantially reduced along the Oregon and Washington coasts (Chapter 8). Riparian woodlands have been affected all across the region, particularly in lowland agricultural valleys and urban areas. The Columbia and Snake rivers, once the world's greatest producers of salmon, have become a series of warm water lakes except for a short stretch that runs past one of the most environmentally contaminated lands in North America, the nuclear reservation at Hanford, Washington. Fifty Columbia River salmon stocks have become extinct, and the remaining twenty-five are on a very expensive life support system (Lichatowich 1999). Urban streams have been buried in culverts, channelized, subjected to huge pulses of water from impervious surfaces, and polluted with oil, gasoline, and assorted street gunk (Booth 1991).
(Continues...)
Excerpted from Restoring the Pacific Northwest by Dean Apostol, Marcia Sinclair. Copyright © 2006 Island Press. Excerpted by permission of ISLAND PRESS.
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Table of Contents
PART I. The Big Picture-Northwest Environmental Geography and History
-Ecological Restoration
PART II. Pacific Northwest Ecosystems
-Bunchgrass Prairies
-Oak Woodlands and Savannas
-Old-Growth Conifer Forests
-Riparian Woodlands
-Freshwater Wetlands
-Tidal Wetlands
-Ponderosa Pine and Interior Forests
-Shrub Steppe
-Mountains
PART III. Crossing Boundaries
-Urban Natural Areas
-Stream Systems
-Landscape and Watershed Scale
-Restoring Wildlife Populations
-Managing Northwest Invasive Vegetation
-Traditional Ecological Knowledge and Restoration Practice
Conclusion: The Status and Future of Restoration in the Pacific Northwest