Provenance Test Research Articles

Evaluation of zircon U-Pb geochronology as a tool to determine soil provenance in a limestone terrane, Middle TN, USA

Soil can form by bedrock weathering or by deposition of alluvial or aeolian material. To test the utility of detrital zircon UPb geochronology for determining soil provenance, and to determine the provenance of soils in Middle Tennessee, samples of soil and underlying bedrock were collected from two sites, along with alluvium from a nearby river and loess from West Tennessee. Multi-dimensional scaling plots were used to compare complex detrital zircon LA-ICP-MS UPb sample age distributions. Concentration ratios of immobile elements and Nd and Hf isotope compositions were also used as provenance indicators for comparison. At one site zircon UPb ages and bulk sample trace element and isotopic compositions of soil were similar to the underlying limestone bedrock, indicating soil formation by bedrock weathering. In contrast, at a second site provenance tests indicate that soil from a late Pleistocene river terrace was sourced from alluvium rather than the underlying bedrock. Provenance inferences based on zircon UPb ages were generally consistent with evidence from Zr/Hf ratios and Hf isotope compositions, which are all dominated by zircon, and Nd isotope compositions, which are not, although the best matches for different provenance indicators did not always agree. Zircon geochronology should be used with other soil provenance indicators to reduce effects of bias introduced by sedimentary sorting and sample processing.

Morphological traits of Scots pine (Pinus sylvestris L.) in international provenance tests in Bosnia and Herzegovina

Scots pine (Pinus sylvestris L.) is one of the most important tree species in European forests. This study aims to determine whether there is inter-provenance variability in researched morphological traits in two international provenance tests of Scots pine in Bosnia and Herzegovina. We measured height, root collar diameter, and latest shoot length and counted branches on the latest branch whorl of Scots pine plants in two provenance tests. The provenance tests are located in Kupres and Žepče, in different climatic, edaphic, and orographic conditions. Kupres and Žepče contain 15 and 14 provenances, respectively, eleven of which are mutual to both sites. Descriptive statistics and analysis of variance showed differences among provenances in all investigated morphological traits. These differences were attributable to provenance test, provenance, and interaction between provenance test and provenance. The average values were higher in Žepče for all provenances and all studied traits. The Austria A1, Austria A2, Austria A3, and Poland P1 provenances showed the best growth in both tests, while the Italy I1 provenance showed good growth in Žepče but not in Kupres.

In vitro ESTABLISHMENT OF Eucalyptus AND Corymbia SPECIES FROM EPICORMIC SHOOTS

ABSTRACT The importance of Eucalyptus and Corymbia has been evident in forestry programs, mainly due to their adaptation to various environmental conditions and the multiple products that can be obtained. As the selection and cloning of superior individuals are usually performed in adulthood, the development and adaptation of the vegetative propagation techniques that enable the rescue and in vitro establishment of species are necessary. Thus, the present study aimed to induce epicormic shoots from pruned branches of adult trees and to promote the in vitro establishment of nine species: six of Eucalyptus and three of Corymbia. The material used to obtain the explants came from the selection of two 44-year-old mother plants of each species, from species, and provenance tests. The number of buds and shoots of each branch was evaluated at 15, 25, 35, and 45 days after the beginning of the experiment in a greenhouse. According to the results, the induction of epicormic shoots from pruned branches was considered a viable and efficient technique to obtain propagule sources from adult mother plants of all species, presenting a gradual increase in the evaluated characteristics over time. Also, in vitro culture is an effective alternative to improve the propagation of the evaluated species, with an establishment of up to 62.5%. However, for Corymbia citriodora (Hook.) K.D. Hill & L.A.S Johnson and Eucalyptus tereticornis Smith it is necessary to develop further studies to enable the in vitro establishment.

Varijabilnost sadržaja kalijuma u četinama kanadskih provenijencija duglazije

The provenance test model is based on the analysis of growth, anatomical, physiological, chemical, mechanical, and other properties of an allochthonous species to justify its transfer from the place of origin to new ecosystems. Douglas-fir is one of the most common allochthonous conifer species in the forest plantations of Europe. Given that the analysis of different physiological properties of trees is important for the introduction of specified provenances into new habitats, this paper presents the results of an investigation of the variability of potassium content in young Douglas-fir needles of 14 Canadian provenances raised on two experimental sites in Belgrade. Potassium is an essential element involved in a number of biochemical and physiological processes and plays a significant role in the adaptation of plants on biotic and abiotic stress factors. Determination of the deviation of potassium content in the needles of each Douglas-fir provenance studied was performed using the Z-test.

Sandalwood provenance test (Santalum album) in Watusipat, Gunungkidul, Yogyakarta

Abstract. Setiawan SD, Yuda IP, Hadiyan Y. 2019. Sandalwood provenance test (Santalum album) in Watusipat, Gunungkidul, Yogyakarta. Pros Sem Nas Masy Biodiv Indon 5: 414-418. In Indonesia, Sandalwood (Santalum album Linn.) has been facing the population declining in the period of the year 1988-1998. For that reason, the Center for Forest Biotechnology and Tree Improvement Research and Development Yogyakarta has initiated to establish the ex-situ conservation (provenance trial) plot in Watusipat, Gunungkidul to protect the remaining its genetic resources. There were 5 sandalwood provenances conserved at Block A: Sumba, TTU, Belu, Rote, and Imogiri planted 2005. The research was designed at Randomized Complete Block Design (RCBD) with 4 provenances observed, 4x4 square plot, 4 replication with 3m x 3m spacing. This study was conducted to know the variation and the best growth of four sandalwood provenances tested. This research was conducted by calculating the survival rate and measuring several growth parameters (stem diameter, height, bole length and crown diameter). The results showed that the variation of survival, diameter, height dan crown diameter were significant different while bole length was not. Rote provenance was the best.

Effect of Seed Transfer on Selected Wood Quality Attributes of Jack Pine (Pinus banksiana Lamb.)

So far, few studies have considered the impacts of seed sources transfer on jack pine (Pinus banksiana Lamb.) wood quality, although wood quality attributes (WQA) in general and the differences between juvenile and mature wood in particular will determine suitability of the produced wood for end-uses. The main objective of this study was to examine the possibility of selecting superior jack pine provenances based on selected WQA. Twenty-two provenances of jack pine were planted in 1964 in Petawawa Research Forest, ON, Canada, as part of a provenance test. The plantation location offers conditions close to optimum for jack pine growth. Transition ages at breast height, determined with tracheids length, were computed with a piecewise model. Measurements at age 42 from seed were subjected to analyses of variance. Radial variations from pith to bark, as well as trends with seed sources origin of the selected WQA were also considered. A ranking was made based on a selection index built with four WQA. The provenances matured between 8 and 14 years, corresponding to 17%–48% of juvenile wood proportion. Significant differences among provenances were observed for ring width, ring density, tracheid length, and diameter at breast height but not for tracheid diameter, tree height, transition age, and juvenile wood proportion. None of the provenances ranked the best with all the selected WQA, but it was possible to find provenances exhibiting both high growth rate and good wood quality. A surprising result of this study was that tracheid diameter initially enlarged for 8 years, before declining toward the bark. It is possible to select provenances for a higher growth rate and for good physical (i.e., related to wood density) and anatomical (i.e., related to tracheid dimensions) wood quality attributes.

Growth Tendency of Quercus robur L. Provenances in Bosnia and Herzegovina Provenance Test with Relation to Fixation Index

Aim of study: Specific genetic structure of the remaining populations of pedunculate oak (Quercus robur L.) in Bosnia and Herzegovina makes them significant for the preservation of the diversity of this species in Bosnia and Herzegovina and Europe. For this reason, we established provenance test in 2009. The aim of the study is to determine the correlation between provenance growth and fixation index. The ultimate goal is the reintroduction of the species in suitable areas. Material and method: The research included measuring the height and the root collar diameter of four-, six- and eight-year-old plants in the provenance test and molecular analyses using isoenzymes. Main results: Variance analysis showed statistically significant differences between populations in all tested characteristics, which was confirmed by the Duncan test. Provenances of Miljevina Foča, Stojčevac, and Visoko Muhašinovići are at the bottom of the list with the lowest growth of four-, six-, and eight-year-old plants. Provenances of Drvar, Mutnica Cazin, Kaćuni, and Jelah showed the best growth. Highlights: Eight provenances showed positive fixation index values, particularly Miljevina Foča, Bosanska Dubica, and Drvar. Positive fixation index value of Miljevina provenance matches its low growth, while this is not the case in Drvar and Bosanska Dubica provenances.

Natural growing site and cultivation of Pongamia (Pongamia Pinnata (L.) Pierre) as a source of biodiesel raw materials

Pongamia (Pongamia pinnata (L.) Pierre) is one of biodiesel source raw material plants. Natural site conditions and an appropriate planting technique of this species are necessary to be investigated. The purpose of this study was to assess the quality of natural growing site and the cultivation of pongamia through the plantation of seedlings based on provenances. The seedlings were originated from 5 different populations of Java Island. Soil was sampled at each location to determine the rate of soil fertility in natural habitat compared to soil sample at cultivation site. The plantation was carried out in Parungpanjang Research Forest with spacing of 3 m x 3 m. Characteristics of growth observed up to 6 months old were total height, stem base diameter, seedling survival percentage and leaf number. The results showed that pongamia in Java grows in less fertile natural habitats. The initial growth of pongamia provenance test in Parungpanjang showed that seedlings from Carita had the best growth of height (83.75 cm) and diameter (0.85 cm). Pongamia was able to adapt to the environmental conditions which are different from its natural conditions, indicated by the high percentage of survival i.e ranging from 88% (Kebumen) to 100% (Batukaras).

Genetic, spatial, and temporal aspects of decline and mortality in a Fraxinus provenance test following invasion by the emerald ash borer

We report a 6-year study of an irruptive invasion of emerald ash borer (EAB) into a 36-year-old comparison of 60 green ash (Fraxinus pennsylvanica Marsh.) and 5 white ash (F. americana L.) populations. As the infestation progressed, annual measures of EAB injury (density of adult emergence holes on the trunk, crown condition, and mortality) were significantly influenced by genetic effects (population and in some instances family within population), site quality (field blocks), and neighborhood (contagion effects over distances of 5–13 m). At the last measurement, 99% of green ash trees and 87% of white ash were dead, and most of the remaining few trees had badly deteriorating crowns. Although final destruction was nearly complete, the rapidity with which trees were injured and killed was moderated by genetic and site effects and influenced by proximity to infested trees. These facts suggest that some genotypes, especially on favorable sites, will disproportionately survive under future equilibrium conditions with lower densities of ash and EAB in the landscape.

Geographical variation and the response to hydrothermal factor of stable carbon isotope (δ13C) in Pinus massoniana.

We used 10 representative provenances at different latitudes in two 33-year-old Pinus massoniana provenance test stands (Chun'an Laoshan in Zhejiang and Taizi Mountain Shilong in Hubei) to measure the differences among provenances, study the geographical variation, and identify its responses to hydrothermal factors. The results showed that the δ13C of the average annual rings was significantly different among the provenances of P. massoniana, being higher in trees from high latitude than from low latitude. The δ13C of average annual rings showed a zonal variation trend, indicating an adaptation to the original environment. The δ13C of annual rings was negatively correlated with mean annual temperature (MAT), mean temperature in January (T1), annual precipitation (MAP), precipitation from May to September (P5-9) and cumulative temperature above 10 ℃ (CT). It was positively correlated with the aridity index (AI). The response function of AI toδδ13C annual rings in Chun'an and Taizi Mountain explained 37.5% and 42.5% of the variation, respectively, indicating that AI was the most important limiting factor. The Taizi Mountain test site in Hubei Province located in the central and western region with relatively dry soil and high aridity. Therefore, the δ13C of the average annual ring was 1.8% higher than that in the Chun'an test site. The δ13C rings of P. massoniana at the Taizi Mountain and Chun'an were sensitive to the temperature in July and August, respectively. Summer precipitation was the main factor for carbon isotope fractionation with stable rings. The sensitivity of different provenances to future climate changes was different.

A Review on Turkish Hazel (Corylus colurna L.)

Background and Purpose: Turkish hazel (Corylus colurna L.) has been overused because of its valuable wood. Recently, Turkish hazel has been found only in small isolated populations, and very small populations within its natural distribution area, so it has been protected under IUCN with the status "Least Concern (LC)". Therefore, the remaining Turkish hazel populations have a critical importance. Genetic conservation of this tree species plays a key role in sustainable forest development. There have been only a few studies of single populations, but an overview including all countries is still missing. The aim of this publication is to give an overview of ecological and economic importance of Turkish hazel, which is considered as a tolerant tree species to climate change, for dry and warm conditions in Central Europe. Materials and Methods: This review paper has been prepared based on the existing literature such as reports, theses, project documents and publications related to Turkish hazel. This paper applies a literature review of the concepts of: i) Distribution and threats of Turkish hazel, ii) Ecological and economic importance, iii) Regeneration, soil demand and shading tolerance, iv) Seed, seedling, plant production and planting, v) Competitiveness in forest communities, vi) Invasiveness and hybridization, and vii) Future stand mixtures. Results and Conclusions: This review paper should interest forest practitioners and scientists in all countries who work with this important and valuable tree species under climate change. At first, an inventory of all populations in each country is needed. For this purpose, research should focus on the cultivation of convenient provenances of Turkish hazel under climate change. Next, genetic differences should be determined in the laboratory using genetic markers. After the assessment of the phenotype and genotype of different provenances, it would be possible to recommend provenance for each ecological condition and assisted migration (AM). Main recommendations for each country are used for selecting and establishing gene conservation units (in-situ and ex-situ) and seed orchards that will ensure the survival of Turkish hazel, and for building the base for cultivation in the future. In addition, the results might be a basis for future provenance tests, plantations and possibilities of assisted migration attempts.

Adaptation to climate in five eastern North America broadleaf deciduous species: Growth clines and evidence of the growth-cold tolerance trade-off

Clines in genetic variation along climate gradients documented for many species in temperate and boreal forests illustrate adaptation of forest tree populations to climate. Adaptation tends to involve balancing selection between high growth rates and stress resistance: a trade-off in resource allocation between stress tolerance and competitive ability that determines fundamental life history strategies. The growth-cold tolerance trade-off, in particular, has been well documented for many conifers but evidence in broadleaf deciduous species is scarce. Using populations’ mean total tree height and provenance climate from range-wide provenance tests established in the USA between 1960 and 1975, we evaluate and model growth clines along climatic gradients and assess evidence of the growth rate-cold tolerance trade-off in five eastern North America broadleaf deciduous species: Acer rubrum (red maple), Betula alleghaniensis (yellow birch), Juglans nigra (black walnut), Prunus serotina (black cherry), and Quercus rubra (northern red oak). Number of populations and provenance tests in this study varies by species, ranging from 31 to70 and 4 to 8, respectively. For each species, observations were separated into two groups, those where the population was moved to a test site climate milder than at its origin, and those where the population was moved to a colder test site climate. Clines of growth potential along climate gradients were evaluated using the group of observations in which the populations had been transferred to a milder test climate, while cold-limited responses were evaluated using the observations in the group of populations moved to colder test climate. Results showed steep clines in association with temperature variables for black walnut and black cherry and less pronounced clines for red maple. Population differentiation in northern red oak and yellow birch was weak. Growth potential clines had slopes opposite to the cold-limited growth responses, providing strong evidence for the growth-cold tolerance trade-off in broadleaf deciduous species. The results show that genetic growth responses to climate will differ considerably among species and thereby demand different management strategies to mitigate climate change impacts.

Common garden comparisons confirm inherited differences in sensitivity to climate change between forest tree species.

The natural distribution, habitat, growth and evolutionary history of tree species are strongly dependent on ecological and genetic processes in ecosystems subject to fluctuating climatic conditions, but there have been few experimental comparisons of sensitivity between species. We compared the responses of two broadleaved tree species (Fagus sylvatica and Quercus petraea) and two conifer tree species (Pinus sylvestris and Picea abies) to climatic transfers by fitting models containing the same climatic variables. We used published data from European provenance test networks to model the responses of individual populations nested within species. A mixed model approach was applied to develop a response function for tree height over climatic transfer distance, taking into account the climatic conditions at both the seed source and the test location. The two broadleaved species had flat climatic response curves, indicating high levels of plasticity in populations, facilitating adaptation to a broader range of environments, and conferring a high potential for resilience in the face of climatic change. By contrast, the two conifer species had response curves with more pronounced slopes, indicating a lower resilience to climate change. This finding may reflect stronger genetic clines in P. sylvestris and P. abies, which constrain their climate responses to narrower climatic ranges. The response functions had maxima that deviated from the expected maximum productivity in the climate of provenance towards cooler/moister climate conditions, which we interpreted as an adaptation lag. Unilateral, linear regression analyses following transfer to warmer and drier sites confirmed a decline in productivity, predictive of the likely impact of ongoing climate change on forest populations. The responses to mimicked climate change evaluated here are of considerable interest for forestry and ecology, supporting projections of expected performance based on “real-time” field data.

Varijabilnost prečnika smolnih kanala u četinama različitih provenijencija duglazije

Douglas-fir is the most commonly grown allochthonous species in the forests of Europe. Growth speed, adaptive power, favorable wood properties, as well as low sensibility to pests are the attributes that have contributed the most to the success and occurrence of Douglas-fir plantations in Europe. Introduction program of an exotic species includes testing of its provenances in new ecosystems and localities. In Serbia, testing of the genetic potentials of Douglas-fir, native to North America, has begun by seting up provenance trials on several locations. Afforestation with exotic tree species must be justified and it should fulfill the aims of the introduction. Therefore, it is neccessary to test all the traits of the introduced species to show the effects of ecological factors. The aim of this research was to determine the ecological adaptations of Douglas-fir in Serbia by studying its anatomic characteristics. In the paper, the influence of locality conditions on the diameter of resin canals in the needles of different Douglas-fir provenances was investigated on the sites where the provenance tests were set up. A two-way ANOVA was performed, by investigating the effects of site and provenance factors on the diameter of resin canals. Resin canals serve as an important diagnostic taxonomic characteristic in conifers, while resin itself has important physiological and protective role in conifers.

Variability of potassium concentration in the needles of Douglas-fir provenances

Douglas-fir is one of the most common conifer species in the forest plantations of Europe. The provenance test model is based on the analysis of the properties (growth, anatomical, physiological, chemical, mechanical and other properties) of Douglas-fir in order to justify the transfer of seeds from North America to the ecosystems of Serbia. This type of program has been implemented in Serbia on several locations using different Douglas-fir provenances. Given that the analysis of different physiological properties of trees is important for the introduction of specified provenances into habitats in Serbia, in this paper the variability of potassium concentration in young Douglas-fir needles of different provenances was examined in an experimental field in Serbia. Potassium is very important in the physiological processes of plants. It is an essential element involved in a number of biochemical and physiological processes and plays a significant role in the adaptation of plants on biotic and abiotic stress factors. The highest potassium concentration was found in the ?Oregon 205-14? provenance - the only provenance in which the potassium concentration was significantly higher than the average value, so it can be characterized as a superior provenance for the uptake and accumulation of this element. It was found that, at this stage of development, the differences in the potassium concentration in trees in the provenance test have no significant effect on growth parameters. Further studies should show whether the concentration of this biogenic element in any way affects other properties important for the selection of provenances during the introduction process, such as resistance to stress factors.

Effect of site and provenance on the length of transfusion parenchyma of Douglas-fir needles

Douglas-fir has been the most common introduced conifer species in European plantations since 1825. The analysis of the characteristics of the introduced tree species by conducting genetic tests may predict the success of transfer of Douglas-fir seed of different provenances. The projection of the model of provenance test aims at providing information on adaptation to habitat and climate conditions in new ecosystems in Serbia. The original seed of Douglas-fir from North America was used for setting the experiment of different provenances at two sites in Serbia. The first experiment was set in a beech forest (Fagetum moesiacae montanum Jov. 1976) on district cambisol in the area of Juhor mountain in central Serbia, while the second one was set in Tanda near the town of Bor in eastern Serbia on the habitat of Hungarian and Turkey oak (Quercetum frainetto-cerris Rud. 1949) on eutric cambisol. Through the analysis of the anatomical structure of Douglas-fir needles this paper tends to determine whether there are statistically significant differences in the length of transfusion parenchyma of provenances located in different habitats. The important function of parenchyma in needles is the physiological process of water, organic and mineral matter flow. The effects of the sites where the experiments were set on the transfusion parenchyma of needles were determined by statistical analysis.

Evidence for population differentiation among Jeffrey and Ponderosa pines in survival, growth and phenology

Ecological restoration projects that include reforestation require that land managers select appropriate source of seeds for long-term persistence. In California, the standard approach for making this choice is based on seed zone and elevational band, both geographically-based measures. However, given the pace of contemporary climate change, populations previously adapted to local conditions may become increasingly mismatched to the changes in climate. If there is a lag in adaptation, current seed zones which assume local is best, would be less useful for reforestation guidelines. Here we use a historic provenance test to evaluate genetic differences among provenances of two species of pine, Pinus ponderosa and P. jeffreyi, and assess performance following seedling transfer across an elevational gradient. Growth in Ponderosa pine shows evidence of a lag in adaptation: trees transferred from lower elevations had consistently increased growth when compared to those trees from higher elevations. In contrast, Jeffrey pine showed no evidence of a lag in adaptation for height. However, survival of Jeffrey pine provenances showed a significant quadratic relationship with transfer distance, consistent with local adaptation. In particular, Jeffrey pine trees from cooler, higher elevation sites had increased survival at high elevation. Jeffrey pine trees from higher elevation also exhibited earlier bud burst than trees from lower elevation grown in the same site, consistent with counter-gradient adaptation in phenology. Together, our results show that genetic variation within species is important for tree survival, growth and phenology in different climates. However, species-specific responses to elevational transfer indicates generalizing seed transfer guidelines across conifer species may be challenging and additional information is necessary to inform managed relocation in a changing climate.

Adaptive genetic potential of European silver fir in Romania in the context of climate change

Five provenance tests with twenty-six European silver fir autochthonous populations were used in order to assess the response of populations to climate change. Height growth and diameter at breast height of trees at age 31 years were considered as response variables and eight climate variables as predictors. Climatic variables for the trial sites and for origin location of provenances were calculated from 1961 to 2010. The experiments revealed a large genetic variability within species level and a plastic response to climate change, which certainly has a genetic basis. The transfer to warmer climate has resulted in an increase of the provenances growth, in the trial sites situated on the lower vegetation layer. But growth is significantly influenced by mean annual temperature and annual precipitation of planting site and also by the differences in mean annual temperature, annual precipitation, monthly mean temperature in July and July precipitation between provenance site and test site. These are the climatic factors which should be associated with risk in case of the transfer of forest reproductive materials. The provenance origin should be especially considered if the species will be planted outside of its current climate optimum. The best provenances in terms of total height and diameter at 1.30 m came from origin climate close to site climate, small transfer distances. Based on growth response functions and RCP4.5 scenario, we could project the shifts in species distribution for 2050s and 2100s and identify vulnerable populations.

Study on geographical variation of medicinal ingredients contents in Scutellaria baicalensis from different provenances

In order to investigate the genetic difference on medicinal components of Scutellaria baicalensis from different provenances on the genetic difference, the S. baicalensis provenance tests were arranged by randomized block design.Excavating the crude drugs that have been growing for three years, with the same drying process, the content of baicalin, baicalein, wogonoside, wogonin and laminarin A in S. baicalensis were detected by HPLC, and then the data were analyzed. The results indicated that the content of baicalin in different provenances of S. baicalensis was significantly different (P<0.05), while the variation of baicalein reached extremely significant level (P<0.01). Cluster analysis showed that if the distance was divided by 5.0, the provenances in Chengde, Hebei province were divided into two independent populations, while the other two populations had large geographic spans. The results show that the significant geographical variations exist in the content of medicinal components in S. baicalensis. The study laid a theoretical foundation of provenance selection of S. baicalensis.

Dendroclimatic analysis of white pine (Pinus strobus L.) using long-term provenance test sites across eastern North America

BackgroundThe main objective of this study was to examine the climatic sensitivity of the radial growth response of 13 eastern white pine (Pinus strobus L.) provenances planted at seven test sites throughout the northern part of the species’ native distribution in eastern North America.MethodsThe test sites (i.e., Wabeno, Wisconsin, USA; Manistique, Michigan, USA; Pine River, Michigan, USA; Newaygo, Michigan, USA; Turkey Point, Ontario, Canada; Ganaraska, Ontario, Canada; and Orono, Maine, USA) examined in this study were part of a range-wide white pine provenance trial established in the early 1960s in the eastern United States and Canada. Principal components analysis (PCA) was used to examine the main modes of variation [first (PC1) and second (PC2) principal component axes] in the standardized radial growth indices of the provenances at each test site. The year scores for PC1 and PC2 were examined in relation to an array of test site climate variables using multiple regression analysis to examine the commonality of growth response across all provenances to the climate of each test site. Provenance loadings on PC1 and PC2 were correlated with geographic parameters (i.e., latitude, longitude, elevation) and a suite of biophysical parameters associated with provenance origin location.ResultsThe amount of variation in radial growth explained by PC1 and PC2 ranged from 43.4% to 89.6%. Dendroclimatic models revealed that white pine radial growth responses to climate were complex and differed among sites. The key dendroclimatic relationships observed included sensitivity to high temperature in winter and summer, cold temperature in the spring and fall (i.e., beginning and end of the growing season), summer moisture stress, potential sensitivity to storm-induced damage in spring and fall, and both positive and negative effects of higher winter snowfall. Separation of the loadings of provenances on principal component axes was mainly associated with temperature-related bioclimatic parameters of provenance origin at 5 of the 7 test sites close to the climate influence of the Great Lakes (i.e., Wabeno, Manistique, Pine River, Newaygo, and Turkey Point). In contrast, differences in radial growth response to climate at the Ganaraska test site, were driven more by precipitation-related bioclimatic parameters of the provenance origin location while radial growth at the easternmost Orono test site was independent of bioclimate at the provenance origin location.ConclusionsStudy results suggest that genetic adaptation to temperature and precipitation regime may significantly influence radial growth performance of white pine populations selected for use in assisted migration programs to better adapt white pine to a future climate.