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

1997 ◽  
Vol 11 (3) ◽  
pp. 747-758 ◽  
Author(s):  
George P. Buchert ◽  
Om P. Rajora ◽  
James V. Hood ◽  
Bruce P. Dancik
1994 ◽  
Vol 24 (8) ◽  
pp. 1726-1733 ◽  
Author(s):  
J. Beaulieu ◽  
J.-P. Simon

The level of genetic diversity of natural populations of eastern white pine (Pinusstrobus L.) from Quebec was estimated from allozyme variants of 18 loci coding 12 enzyme systems. On average, a white pine population was polymorphic at 50.6% of loci, had 1.96 alleles and 1.22 effective alleles per locus, and observed and expected heterozygosities of 0.176 and 0.180, respectively. The level of genetic diversity was lower in the populations of the St. Lawrence lowlands than in those of western Quebec. This observation will help in guiding the selection program of the eastern white pine improvement program under way in Quebec. Genetic differentiation among sampled populations was weak and accounted for only 2% of the total diversity. The estimate of gene flow was very high, resulting in low values for genetic distances among populations. Only one locus showed a heterogeneity of allelic frequencies among populations after the Bonferroni procedure was applied for simultaneous statistical tests. A cluster analysis based on genetic distances among populations revealed that the Anticosti and Abitibi populations, located at the limit of the natural range of white pine, were similar to populations from regions that were geographically the most distant.


2020 ◽  
Author(s):  
Robert T. Leverett ◽  
Susan A. Masino ◽  
William R. Moomaw

AbstractPre-settlement New England was heavily forested, with some trees exceeding 2 m in diameter. New England’s forests have regrown since farm abandonment and represent what is arguably the most successful regional reforestation on record; the region has recently been identified as part of the “Global Safety Net.” Remnants and groves of primary “old-growth” forest demonstrate that native tree species can live for hundreds of years and continue to add to the biomass and structural and ecological complexity of forests. Forests are an essential natural climate solution for accumulating and storing atmospheric CO2, and some studies emphasize young, fast-growing trees and forests whereas others highlight high carbon storage and accumulation rates in old trees and intact forests. To address this question directly within New England we leveraged long-term, accurate field measurements along with volume modeling of individual trees and intact stands of eastern white pines (Pinus strobus) and compared our results to models developed by the U.S. Forest Service. Our major findings complement, extend, and clarify previous findings and are three-fold: 1) intact eastern white pine forests continue to sequester carbon and store high cumulative carbon above ground; 2) large trees dominate above-ground carbon storage and can sequester significant amounts of carbon for hundreds of years; 3) productive pine stands can continue to sequester high amounts of carbon for well over 150 years. Because the next decades are critical in addressing the climate crisis, and the vast majority of New England forests are less than 100 years old, and can at least double their cumulative carbon, a major implication of this work is that maintaining and accumulating maximal carbon in existing forests – proforestation - is a powerful near-term regional climate solution. Furthermore, old and old-growth forests are rare, complex and highly dynamic and biodiverse, and dedication of some forests to proforestation will also protect natural selection, ecosystem integrity and full native biodiversity long-term. In sum, strategic policies that grow and protect existing forests in New England will optimize a proven, low cost, natural climate solution for meeting climate and biodiversity goals now and in the critical coming decades.


2021 ◽  
Vol 12 ◽  
Author(s):  
Om P. Rajora ◽  
John W. R. Zinck

Whether old-growth (OG) forests have higher genetic diversity and effective population size, consequently higher conservation value and climate adaptive potential than second-growth (SG) forests, remain an unresolved issue. We have tested the hypothesis that old-growth forest tree populations have higher genetic diversity, effective population size (NE), climate adaptive potential and conservation value and lower genetic differentiation than second-growth forest tree populations, employing a keystone and long-lived conifer, eastern white pine (EWP; Pinus strobus). Genetic diversity and population structure of old-growth and second-growth populations of eastern white pine (EWP) were examined using microsatellites of the nuclear and chloroplast genomes and single nucleotide polymorphisms (SNPs) in candidate nuclear genes putatively involved in adaptive responses to climate and underlying multilocus genetic architecture of local adaptation to climate in EWP. Old-growth and second-growth EWP populations had statistically similar genetic diversity, inbreeding coefficient and inter-population genetic differentiation based on nuclear microsatellites (nSSRs) and SNPs. However, old-growth populations had significantly higher chloroplast microsatellites (cpSSRs) haploid diversity than second-growth populations. Old-growth EWP populations had significantly higher coalescence-based historical long-term NE than second-growth EWP populations, but the linkage disequilibrium (LD)-based contemporary NE estimates were statistically similar between the old-growth and second-growth EWP populations. Analyses of population genetic structure and inter-population genetic relationships revealed some genetic constitution differences between the old-growth and second-growth EWP populations. Overall, our results suggest that old-growth and second-growth EWP populations have similar genetic resource conservation value. Because old-growth and second-growth EWP populations have similar levels of genetic diversity in genes putatively involved in adaptive responses to climate, old-growth, and second-growth populations may have similar adaptive potential under climate change. Our results could potentially be generalized across most of the boreal and temperate conifer forest trees. Our study contributes to address a long-standing issue, advances research field and knowledge about conservation and ecological and climate adaptation of forest trees.


1998 ◽  
Vol 76 (3) ◽  
pp. 500-508 ◽  
Author(s):  
Om P Rajora ◽  
Linda DeVerno ◽  
Alex Mosseler ◽  
David J Innes

The dramatic decline of eastern white pine (Pinus strobus L.) populations in Newfoundland over the past 100 years presents an opportunity to determine and monitor population bottleneck effects on genetic diversity in trees. To provide benchmarks and indicators for monitoring genetic changes due to recent and future bottleneck events and to assist development of conservation strategies, we assessed genetic diversity and structure of six small, isolated white pine populations from two regions at the limits of its geographical range in Newfoundland for comparison with three populations from its central range in Ontario for 20 allozyme loci coding for 12 enzymes. On average, 47.8% of the loci were polymorphic, the number of alleles per locus was 1.75, and the observed and expected heterozygosities were 0.215 and 0.195, respectively. Although most of the alleles were widespread, unique alleles were found in three of the nine populations examined. The Newfoundland populations were as genetically variable as those from Ontario. Generally, all populations exhibited slight excess of heterozygotes at most loci. Only 6.1% of the detected genetic variation was among populations, and the remainder among individuals within populations. The genetic distances among the populations within a province or region were as great as those among populations between the provinces or regions. Canonical discriminant functions and cluster analysis from genetic distances separated nine populations into the same four groups. Neither provincial nor regional or geographic gradient-related patterns of population variation and differentiation were apparent. It appears that 8000 years of postglacial geographic isolation and recent population decline have had little or no detectable effect on genetic diversity or differentiation of disjunct Newfoundland white pine populations from their ancestral mainland populations. Assuming their adaptability, the Ontario seed sources may be acceptable for white pine restoration in Newfoundland.Key words : Pinus strobus, allozymes, gene conservation, genetic diversity and population structure, genetic drift, population bottleneck.


2010 ◽  
Vol 86 (5) ◽  
pp. 614-622 ◽  
Author(s):  
William C. Parker ◽  
Thomas L. Noland ◽  
Brian Brown

Seed production and seed characteristics were examined during a mast seeding year in unmanaged, old-growth eastern white pine (Pinus strobus L.) stands located in northeastern Ontario and compared with those in adjacent stands partially harvested 16 years earlier using a structural retention system. Seed yields from old-growth stands were comparable to those of mature, second growth white pine stands but seed production assessed relative to unit area (# ha-1) and pine basal area (# m-2) was lower in partially harvested stands. In both unmanaged and harvested stands, seed production rate of trees growing in localized areas of lower pine basal area was higher. Seed characteristics and seed viability did not differ between harvest treatments. Although structural retention harvesting reduced seed production, results suggest that supply and viability of seed are unlikely to limit seedling recruitment in managed or protected old-growth white pine forests. Key words: germination, old-growth forest, partial harvest, seed mass, seed production


Trees ◽  
2004 ◽  
Vol 18 (1) ◽  
pp. 29-34 ◽  
Author(s):  
William G. Cole ◽  
David Balsillie ◽  
Daniel P. Bebber ◽  
Sean C. Thomas

2007 ◽  
Vol 37 (12) ◽  
pp. 2652-2662 ◽  
Author(s):  
Paula E. Marquardt ◽  
Craig S. Echt ◽  
Bryan K. Epperson ◽  
Dan M. Pubanz

Resource sustainability requires a thorough understanding of the influence of forest management programs on the conservation of genetic diversity in tree populations. To observe how differences in forest structure affect the genetic structure of eastern white pine ( Pinus strobus L.), we evaluated six eastern white pine sites across the 234 000 acre (1 acre = 0.4046856 ha) Menominee Indian Reservation in northeastern Wisconsin (45°00′N, 88°45′W). The six sites sampled for nuclear and chloroplast DNA microsatellite markers were of contrasting densities and managed by different management systems: shelterwood, pine release, plantation, and old growth. Three of the sites had natural regeneration, which was also sampled. Mean values of spatial genetic autocorrelation were positive in all mature populations and variable; the strongest spatial structuring of genes occurred in the least disturbed old-growth site (I – E(I) = 0.031). Genetic structuring at the historical old-growth site fit the isolation-by-distance model for a neighborhood size of 130 individuals. Significant inbreeding occurred in five populations, but the seedling or sapling populations as a group (f = 0.088) are significantly less inbred than the local mature populations (f = 0.197). The increase in heterozygosity between generations was attributed to harvesting having reduced the spatial genetic structure of the mature trees.


2021 ◽  
Vol 4 ◽  
Author(s):  
Robert T. Leverett ◽  
Susan A. Masino ◽  
William R. Moomaw

Pre-settlement New England was heavily forested, with trees exceeding 2 m in diameter. The forests have regrown since farm abandonment, representing what is arguably the most successful regional reforestation on record and identified recently in the “Global Safety Net.” Temperate “old-growth” forest and remnant stands demonstrate that native tree species can live several hundred years and continue to add to forest biomass and structural and ecological complexity. Forests globally are an essential natural climate solution that accumulate carbon and reduce annual increases in atmospheric CO2 by approximately 30%. Some studies emphasize young, fast-growing trees and forests while others highlight carbon storage and accumulation in old trees and intact forests. We addressed this directly within New England with long-term, accurate field measurements and volume modeling of individual trees and two stands of eastern white pines (Pinaceae: Pinus strobus) and compared our results to models developed by the U.S. Forest Service. Within this sample and species, our major findings complement and clarify previous findings and are threefold: (1) beyond 80 years, an intact eastern white pine forest can accumulate carbon above-ground in living trees at a high rate and double the carbon stored in this compartment in subsequent years; (2) large trees dominate above-ground carbon and can continue to accumulate carbon; (3) productive stands can continue to accumulate high amounts of carbon in live trees for well over 150 years. Because the next decades are critical in addressing the climate emergency, and most New England forests are less than 100 years old, a major implication of this work is that maintaining and accumulating carbon in some existing forests—proforestation—is a powerful regional climate solution. Furthermore, older and old-growth trees and forests are rare, complex, highly dynamic and biodiverse: dedication of some forests to proforestation will produce large carbon-dense trees and also protect ecosystem integrity, special habitats, and native biodiversity long-term. In sum, strategic policies to grow and protect suitable existing forests in New England will optimize a proven, low cost, natural climate solution that also protects and restores biodiversity across the landscape.


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