The Conservation of Forest Genetic Resources Case Histories from Canada, Mexico, and the United States

The Conservation of Forest Genetic Resources Case Histories from Canada, Mexico, and the United States value of gene banks in the conservation of forest genetic resources. By E Thomas Ledig, J.JesusVargas-Hernandez, and Kurt H. Johnsen Prepared as a task of the Forest Genetic Resources Study Group/North American Forestry CornrnissioniFood and Agriculture Organization of the United Nations. Reprinted from the Joul-rzal of Forestry, Vol. 96, No. 1, January 1998. Not for further reproduction. e Conservation of Forest Case Histories from Canada, Mexico, and the United States he genetic codes of living organ- taken for granted: release of oxygen and isms are natural resources no less storage of carbon, amelioration of cli- T than soil, air, and water. Genetic mate, protection of watersheds, and resources-from nucleotide sequences others. Should genetic resources be lost, in DNA to selected genotypes, popula- ecosystem function may also be dam- tions, and species-are the raw mater- aged, usually expressed as a loss of pri- ial in forestry: for breeders, for the for- mary productivity, the rate at which a est manager who produces an eco- plant community stores energy and pro- nomic crop, for society that reaps the duces organic matter (e.g., Fetcher and environmental benefits provided by Shaver 1990). Losses in primary pro- forests, and for the continued evolu- ductivity result in changes in nutrient tion of the species itself. and gas cycling in Breeding, of course, The loss g~f;a ecosystems (Bormann requires genetic variation. and Likens 1979). Continued improvement p population is Genetic diversity is in medicines, agricultural the most basic element By F. Thomas Ledig, crops, and forest crops a secret extinction, of biological diversity J.JesusVargas-Hernandez, depends on breeders' ac- and provides the raw and Kurt H. Johnsen cess to genetic resources. eliminating valuable materials by which In terms of human species evolve and adapt economy, we rely on the but often cryptic to changing conditions finely tuned match of (Keystone Center 199 1). organisms to their envi- SaUrCes of diversity. In long-lived forest trees, ronment to maintain genetic diversity may be productivity of our forests. If popula- necessary to buffer against environmen- tions are lost or diversity is reduced, tal variation as well as provide for site productivity can decline (e.g., change on the evolutionary time scale. Ledig 1991). The ultimate loss of ge- Although the value of genetic re- netic resources is the economic loss of sources is generally not contested, commercial species, such as American methods of conserving it are. Discus- chestnut (Cdstanea dentata) and St. sion has centered on whether genetic Helena redwood (Eochetiopsis ery- resources should be conserved in the throxylon). The loss of genetic re- native habitat (in sit4 or in special col- sources can also mean a reduction in lections fexsitu). Genetic resource col- commercial value: the poorly formed lections maintained in seed banks and coastal populations of Calabrian pine field gene banks (such as clone banks (Pinw 6rgtia) in the eastern Mediter- and seedling plantations) are examples ranean result from exploitation in an- of ex situ conservation. For agronomic tiquity (Palmberg 1975), and the crops, conservation in huge seed banks stunted examples of mahogany &ie- is the rule. The US National Seed Stor- tenia mahagoni) in the most accessible age Laboratory in Fort Collins, Col- areas of the Caribbean result from re- orado, maintains more than 46,000 cent exploitation (Styles 1972). separate lots of wheat alone (Chang In a broader sense, the health of soci- 1989). But for forest trees, conserva- ety depends on forest genetic resources tion in the natural habitat has long for the ecological services that are often been considered the better alternative 32 January 1998 Genetic Resources (Rogers and Ledig 1996). Conserva- the cases we chose are not merely ex- Renfrew, and Beachburg to the Upper tion in situ generally is less expensive amples of endangered resources, they Ottawa Valley, an area of 1,719 km' than collecting and managing genetic are, in some respects, success stories (Teich et al. 1975). Although shown to resources in seed banks and allows nat- in conservation. As members of the be genetically distinct, Ottawa Valley ural processes of evolution to continue. Forest Genetic Resources Study white spruce are not taxonomically dis- Also, in situ reserves can serve multiple Group, North American Forestry tinguished from other white spruce. purposes-providing forest products, Commission, Food and Agriculture Demography. Ottawa Valley white recreation, and ecological benefits Organization of the United Nations, spruce has been reduced in extent and (e.g., Ledig 1986; Wilson 1990; Millar we present these cases to draw atten- is threatened with further reduction. and Westfall 1996). tion to the need for conservation From the mid-1880s to the mid- Genetic resources in situ, however, strategies that integrate in situ and ex 1900s, native forests were cut exten- are subject to loss through human ac- situ methods. sively. Until this century, the forest re- tivities or through fire, flood, wind, source was exploited with little or no introduced pests and pathogens, and concern for regeneration. After log- climate change. Donald Falk (1992), ging, much of the area was converted when he was director of the Center to farm and pasture, and natural oc- for Plant Conservation, argued that The white spruce of the Ottawa VdlZq, currence of the commercial tree species ex situ conservation should therefore Ontario, represent a unique gene pool in the valley was greatly reduced. The be an integral component of conser- that is rapidly disappearing @om na- losses continue. vation strategies. Yet no country in ture. Ex situ conservation may be the Genetic variation. Several tests of 9 1 North America has a comprehensive best hope far maintaining this genetic white spruce seed sources were estab- strategy for conserving forest genetic resource far fiture generations. lished in Ontario, and at 13 to 20 years resources or any program for long- the trees from the Beachburg-Cobourg term ex situ conservation. The Cana- White spruce (Picea glauca) is one of corridor averaged 2 1 percent taller dian Forest Service is just beginning the most widely distributed tree species than the local seed source (Teich et al. to develop systematic and compre- in North America. Its range is transcon- 1975). Similar results were observed in hensive collections of Canada's native tinental, extending over most of tests in the Canadian Maritime Region tree species (D. Simpson, pers. corn- Canada and into the northern United and the northeastern and north central mun., 1997), and only a few of States. It is the most-planted tree United States (Fowler and Coles 1977; North America's major commercial species in Canada (Kuhnke 1989) and Genys and Nienstaedt 1979). In species are adequately maintained, is included in several commercial and British Columbia, Upper Ottawa Val- generally by university-industry tree provincial tree improvement programs. ley white spruce not only grow very improvement cooperatives. Seed source tests (also called com- well, they are also resistant to weevil at- The case studies below are com- mon garden tests and provenance tests) tack (Kiss et al. 1994). The value of pelling arguments for national pro- of white spruce were established in the these genetic resources is recognized by grams of ex situ conservation (e.g., as 1950s to quantie and analyze genetic breeders throughout Canada and the outlined in Ledig 1992) as insurance variation for breeding programs. In northern United States. Breeders from against the loss of forest genetic re- many tests across eastern Canada and as far away as the Canadian Maritimes sources in their natural habitat. the northeastern United States, white and British Columbia have incorpo- These three examples illustrate the spruce seed lots that originated in the rated Upper Ottawa Valley white breadth, severity, and international Upper Ottawa Valley in Ontario grew spruce in their local breeding programs nature of the genetic conservation as fast as or faster than the local seed (Fowler and Coles 1977; B. Jaquish, issue. We could have chosen numer- sources (e.g., Nienstaedt and Teich pers. commun., 1997). ous examples; many other species are 1972). Best known as Beachburg, su- Conservation. Recognizing the ge- similarly at risk of dramatic reduc- perior sources appear to extend from netic superiority of the Upper Ottawa tions in genetic diversity. However, the vicinity of Pembroke, Douglas, Valley white spruce seed source as well Journal of Forestry 33 as the continued erosion of natural state. The selected trees were probably down and fire, and in the remaining nvo populations, forest geneticists from similar to, and of the same cohort as, stands, populations had been reduced by the Canadian Forest Service and the those sampled for the seed source tests approximately a third by logging and Ontario Ministry of Natural Re- that identified the genetic superiority of home construction. We speculate that sources sought to increase seed avail- the Ottawa Valley white spruce. the nonresponses signie a situation at ability (Winston et al. 1981). Their Sampling took place from winter least as dire. Thus, loss and erosion of the goals were to establish and maintain 1982-83 through winter 1987-88. Suc- natural populations continue. If Upper the following: cessful grafts were made with scions Ottawa Valley white spruce were a Because the clonal archive was imple- earth. In fact, Monterey pine is the the island is officially under control of mented to conserve genetic resources most widely planted exotic conifer the Ministry of the Interior and is valuable to tree breeders, sampling species in the world, covering 4 million guarded by the navy. The only inhabi- within stands was not random; only the hectares in commercial timber and tants are the staff at a small meteorolog- largest, best-formed trees were chosen for pulpwood plantations in New ical station and naval post.

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