PRESERVING PRAIRIES AND SAVANNAS IN A SEA OF FOREST A CONSERVATION CHALLENGE IN THE PACIFIC NORTHWEST ARTICLE AND PHOTOGRAPHS BY ED ALVERSON “We ride a few miles in nature’s Wilderness still persists in the rugged ᮡ Upland prairie in early spring with oak park, the most enchanting mountains but the lowland landscape has Ranunculus occidentalis bordered by scenery of the kind I ever saw, the a different story to tell. Where there is Oregon white oak (Quercus garryana). now a sprawling expanse of developed ground, the trees, all beautiful; landscapes – the cities of Vancouver, stimulate growth of bulbs such as camas such is the variety and beauty of Seattle and Portland, as well as outlying lily (Camassia spp.), facilitate the harvest the flowers as to present themselves farms and industrial forests – there were of seeds and acorns (particularly from in every step; it is like a flower once magnificent conifer forests, punctu- Oregon white oak or Garry oak, Quercus garden, a flower garden, indeed, ated by contrasting areas of prairies and garryana) and prepare small plots of on a large scale, to an extent open canopied savannas or ‘oak meadows’. ground for cultivation of tobacco. The resulting landscape was a mosaic of forest, unmeasured, and it hardly seems Before settlers of European descent savanna and prairie which supported a right that our horses should step.” arrived, the valleys west of the Cascades great diversity of plant and wildlife habi- (which include the Willamette Valley of tats, a model of a sustainable partnership Rev. George Gary Oregon, the Puget Trough of Washington between humans and nature. Oregon City, Oregon, May 1845 and the Georgia Basin of southwest British Columbia) were well populated by From the European perspective, the orthwestern North America, native peoples. These people fished for Arcadian nature of the lowland landscape where the continent meets the salmon, hunted wild game and gathered in the Pacific Northwest comes through NPacific Ocean, is a region of great food plants – roots, bulbs, seeds and berries in the descriptions of early explorers from ecological contrasts. Within the province – from an abundant native landscape. the late 1700s and early 1800s. The of British Columbia (Canada) and the Scottish botanist David Douglas, who states of Washington and Oregon (USA), Prairies and savannas were the most explored the region between 1825 and snowy mountains rise above fertile valleys. important source of food plants to the 1834 in search of seeds of potential new Extremes of climate, from rainforest to native people. They were also the habitats garden plants, described the Willamette desert, temperate to alpine, create a most subject to their management. In Valley in August 1826: “Country undu- complex landscape of diverse habitats. particular, fire in prairies was used to lating, soil rich, light, with beautiful April 2005 PLANTTALK 40 23 ᮤ Golden paintbrush (Castilleja levisecta), much of the remaining prairie landscape. a rare endemic federally listed as endan- By the mid-20th century, the conversion gered, survives at only 12 sites. was nearly complete. Of the original 700,000 ha (1,700,000 acres) of prairie solitary oaks and pines interspersed and savanna habitat that existed in the through it…” Douglas further observed mid-1850s less than 1% remained. As the the extent to which fire influenced the modern age unfolded, nobody seemed to vegetation: … “and must have a fine notice the loss. effect, but being all burned and not a single blade of grass except on the Fortunately, in recent decades, a small margins of rivulets to be seen”. The land- band of conservationists has ‘rediscov- scape turned from black to green after the ered’ the prairies within this sea of forest, fall and winter rains, as described by the and have worked hard to conserve this ‘mountain man’ James Clyman when he landscape which so impressed the early travelled through the same region in May explorers such as David Douglas. One 1845: “I … was highly pleased with the example of this renewed attention is a beautiful variety of hill and valley so softly recently completed assessment of the bio- valled and intermingled with hill and dale diversity of the Willamette Valley-Puget as likewise timber and prairie all luxuri- Trough-Georgia Basin ecoregion (map, antly clothed in a rich and heavy coat of p. 26). It begins with a description of the vegetation and litterally clothed in flow- prairies and savannas and their biological ers the upland in yellow and the valleys in significance, which underscores why they purple. The quantity of small flowering are such important islands of diversity in vegettiles is very remarkable and beyond the Pacific Northwest’s sea of forest. conception.” Ecologists have classified the plant com- munities in the Willamette/Puget/ Grasslands under threat Georgia ecoregion associated with prairies and savannas, representing different As white settlers displaced the native points along moisture and successional people from their traditional homelands, gradients. Seasonal wet prairies (usually the economic imperatives of the settlers found on heavy clay soils) and associated meant the end of the prairies and savan- vernal pools represent the wettest end of nas. The settlers rapidly converted the the moisture gradient. Upland prairies open prairies to fertile agricultural land. They eliminated the periodic fires that ᮢ Meadow checkermallow (Sidalcea had kept the prairies and savannas open, campestris), Willamette Valley endemic. and in this temperate, often rainy climate, the result was more forest. Their abundant cattle, sheep and pigs foraged in areas not cultivated, depleting the grazing-sensitive native grasses and wild- flowers, which were largely replaced by introduced plants from Eurasia. The economic wealth that the land produced encouraged the growth of towns and cities, which further claimed ᮤ Tolmie’s mariposa lily (Calochortus tolmiei), widespread in prairie & savanna. 24 PLANTTALK 40 April 2005 are freely draining in the winter, have the butterflies, Western Meadowlark, ᮤᮡ The different types of prairie: best soils and have been largely converted Western Gray Squirrel, several species of From left to right: Wet prairie in the to farmland. Herbaceous balds and bluffs endemic pocket gophers and reptiles such summer dry season with Deschampsia are associated with bedrock outcrops, and as Gopher and Sharp-tailed snakes. cespitosa as the dominant native grass, are subject to extreme summer drought. near Eugene, Oregon. Savannas have scattered oaks and a In April the floral display in the prairies ground flora similar to upland prairies but and savannas swings into full gear, with A herbaceous bald with parasitic mistle- grade into oak woodlands which support yellow buttercups (Ranunculus occidentalis), toe growing on Oregon white oak, near a moister flora dominated by shrubs. pink shooting stars (Dodecatheon hender- Corvallis, Oregon. sonii), white saxifrage (Saxifraga integri- Prairies and savannas originally only folia) and white Oregon fawn lilies Oak savanna with Oregon sunshine occupied a small proportion of the land (Erythronium oregonum) brightening the (Eriophyllum lanatum), Willamette Valley (most of the rest was coniferous forest) landscape. In May the prairies are often west of Eugene, Oregon. but they contributed significantly to the filled with sheets of purple camas lilies floristic diversity of the region. In fact, (Camassia quamash), accentuated with A vernal pool with Fragrant popcorn- 350 native vascular plant taxa are generally larkspurs (Delphinium spp.), pink sea flower (Plagiobothrys figuratus), in restricted to prairies, savannas and associ- blush (Plectritis congesta), and yellow Basket Slough National Wildlife Refuge, ated oak woodlands in the Willamette/ balsamroot (Balsamorhiza deltoidea). Peak Willamette Valley, Oregon. Puget/Georgia ecoregion. Graminoids are diversity of flowering species is in late dominant throughout the year, with spring; a single square metre of high qual- Camassia quamash in bloom on gravelly seasonal displays of wildflowers. For ity prairie may support over 20 species of glacial outwash soils, Washington. example, 42 species of native grasses are native plants. Increasing summer drought associated with prairie, savanna and oak in July and August brings seed matura- PRESERVING PRAIRIES AND SAVANNAS woodland habitats, as well as 75 species tion and vegetative dormancy, along with IN A SEA OF FOREST of Asteraceae and 30 species of Liliaceae. the burn season, but a few composites The flora includes 32 endemic or near- (Aster spp., Grindelia integrifolia) and endemic taxa. Many of the endemics are umbels (Perideridia montana and P. o r e - ᮢ Kincaid’s lupine (Lupinus sulphureus threatened by habitat loss; 20 of them are gana) flower into late summer and fall. subsp. kincaidii), a rare endemic and considered globally ‘at risk’. federally listed threatened species, in upland prairie, Willamette Valley, Oregon. The prairies and savannas are also home The conservation challenge to many declining wildlife species, such as the Fender’s Blue and Valley Silverspot Just as the prairies and savannas of the Willamette/Puget/Georgia ecoregion ᮢ The rare endemic white rock lark- were important to native people, the spur (Delphinium leucophaeum) survives botanical community of the region has in herbaceous balds and on roadsides. come to appreciate the beauty and diver- sity that these habitats bring to the region. With the start of conservation efforts has also come a better appreciation of the challenge to preserve this heritage for future generations. Habitat inventories have shown that most existing prairie remnants are small, less than 25 ha in size, and only a few are over 100 ha. Conservation efforts are complicated by land ownership patterns, as only small percentages of the total land area (no more than 5–10%) are in public ownership. April 2005 PLANTTALK 40 25 Maintaining native vegetation in these The results of this planning yielded a few remnants is also a challenge. Many ‘portfolio’ or network of sites that best Eurasian weeds, such as bentgrass represents the native species and ecosys- (Agrostis capillaris), velvet grass (Holcus tems.