Genetics of white pine and implications for management and conservation

Abstract

The processes which generate and maintain genetic variabilLes processus qui gCn2rent et maintiennent la diversite gCnCity in natural forest tree populations are reviewed in relation to tique dans les populations naturelles d'arbres forestiers sont genetic management of naturally regenerating white pine (Pinus CtudiCs en relation de la gestion ii des fins gCn6tiques des peuplements strobus L.) stands. Genetic consequences of inbreeding and de pin blanc (Pinus strobus L.) se rCg6nCrant naturellement. Les silvicultural selection on natural regeneration are discussed, consCquences gCnCtiques de l'interfkcondation et de la sClection with special reference to old-growth stand management.sylvicole sur la r6gCnbtion naturelle sont discutks, tout en rCfCrant Ontario's old-growth white pine forests provide a unique sptcialement I'amCnagement des vieux peuplements. opportunity to manage, utilize and conserve pristine gene pools Les vieilles for& de pin blanc de I'Ontario constituent une opporin situ. However, fragmentation of white pine populations in other tunit6 unique pour amCnager, utiliser et conserver des rCserareas may require ex situ methods to preserve remnants of local voirs gCnCtiques originaux in situ. Cependant, la fragmentation genetic variation for future use.des populations de pin blanc dans d'autres rigions requiert des mtthodes ex situ de prkservation pour utilisation future des Key words: white pine, genetic diversity, inbreeding, mating sysderniers vestiges de la variation gCnCtique locale. tems, high-grading, old-growth, genetic resource management, gene conservation Mots cl6s: pin blanc, diversite gtnktique, interfecondation, syst2mes de croisement, CcrCmage, vieilles for&, gestion des ressources gCnCtiques, conservation des gBnes IntroductionEastern white pine (Pinus strobus L.) has been an integral part of the history of eastern No& America. Ranging Erom Georgta to Newfoundland and west through Great Lakes country to Manitoba and Iowa, it has been venerated by Native cultures and has made an invaluable contribution to the economic development and prosperity of European colonies. Once assumed to be in endless abundance, white pine is now a minor forest component in many areas of its range. However, society continues to r e c o m white pine's traditional economic values. Our society-at-large is also beginning to recognize the importance of maintaining and conserving the genetic resources of plant communities where white pine has been and still is a major component. With increasing resource management emphasis on sustainable development, maintenance of biodiversity and ecosystem management, it is imperative that white pine silvicultural practices are based upon a knowledge of population genetics and evolution of natural stands (Namkoong et al., 1988). This paper will briefly review the current understanding of patterns of genetic variation in white pine, and will describe biological mechanisms by which this variation is maintained, enhanced or eroded. It will provide some background understanding of po...

Mating system and reproductive fitness traits of eastern white pine (Pinus strobus) in large, central versus small, isolated, marginal populations

“…Once a common and widespread species throughout northeastern North America, eastern white pine may have undergone fundamental changes in population structure as a result of human interference on the landscape. Harvesting pressures have reduced eastern white pine to small, isolated groups of trees over large portions of its former geographic range (Buchert 1994).…”

Microsatellite DNA analysis of genetic effects of harvesting in old‐growth eastern white pine (Pinus strobus) in Ontario, Canada

“…Once a predominant tree species in forest landscapes of the Great Lakes region of North America, eastern white pine has undergone fundamental changes in population structure and dynamics over 150 years of heavy exploitation ( Buchert 1994). Extensive stand harvesting and high grading (selective harvesting of only the best trees from the stand) of eastern white pine has resulted in forest fragmentation and reduction of its population size ( Buchert 1994). This population reduction may have resulted in genetic changes to local gene pools ( Barnes 1989; Ledig 1992).…”

Effects of Harvesting on Genetic Diversity in Old-Growth Eastern White Pine in Ontario, Canada. Efecto de la Cosecha Sobre la Diversidad Genetica de un Bosque Maduro de Pino Blanco del Este

“…There is mounting evidence that tree populations that have sustained genetic losses are more susceptible to productivity decline and loss of environmental fitness in the event of major environmental changes (Müller-Starck 1985;Bergmann & Scholz 1987;Bergmann et al 1990;Oleksyn et al 1994;Raddi et al 1994). It is not yet clear, however, how harvesting practices, which remove many or most individuals from intact gene pools, affect genetic diversity and genetic processes because no reported studies have attempted to assess and compare total genetic diversity of intact forest tree gene pools with residual genetic diversity of remnant gene pools after human disturbance (Buchert 1994).…”