Pine Progeny Research Articles

The effects of genetics and tree growth on the presence of spike knots in Scots pine progenies

The effects of genetics and tree growth on the presence of spike knots in Scots pine progenies

Genetic variation in height, diameter and second flushing in four-year old maritime pine progeny tests in Türkiye

Abstract A maritime pine (Pinus pinaster Ait.) breeding program was initiated in Türkiye by selecting plus trees from plantations across the country. Quantifying genetic variation in growth traits is essential for this program. Four-year old trees from 140 open-pollinated maritime pine families were assessed for height (HT), root collar diameter (D) and number of shoots in the fourth growing season (S) in three progeny test plantations (Kefken, Gebze and Çatalca) in northwest Türkiye. Growth was greater in Kefken, followed by Gebze and Çatalca. Both individual tree (h i 2) and family mean (h f 2) heritability estimates were greatest for HT (h i 2=0.22 and h f 2 =0.77) followed by D (0.16 and 0.59) and S (0.08 and 0.45). While genetic correlation between HT and D was strong (r A =0.72), S was correlated moderately with HT (0.56) and weakly with D (0.11). Genotype × environment interaction was significant only for D. While modest genetic gains (up to 15.20 % over the average of family means) from selections at age four seem possible for growth, changes in patterns of genetic variation and interrelationships among the traits as the trees age remains to be explored in the future.

Effects of previous land use on genotype-by-environment interactions in two loblolly pine progeny tests

Loblolly pine (Pinus taeda L.) is widely used for forestry in southern Brazil, with most seeds coming from clonal seed orchards. This study investigated the effects of previous land use on the adaptability, stability, and productivity of loblolly pine progenies in southern Brazil, aiming to produce a second-generation clonal seed orchard (CSO). Two progeny tests were installed in southern Brazil. In FARA, 52 open-pollinated loblolly pine progenies were tested, and in TUNAS, 65 open-pollinated loblolly pine progenies were tested, 35 of which were common to both tests. FARA is a rotation area previously used for annual agronomic crops (oats, corn, soy, beans), whereas, TUNAS is a recycled loblolly pine plantation forest. The diameter at breast height (dbh) and stem height were measured at six years of age, and the wood volume was calculated. Genetic parameters were estimated using REML/BLUP method in SELEGEN software. The adaptability, stability, and productivity of the progenies were estimated by the relative performance harmonic mean of the breeding values method (MHPRVG). The breeding values for volume were used to estimate genetic gains through selection. The heritability values were slightly higher in FARA compared to those in TUNAS. Most of the individual narrow-sense heritability values were between 0.10 and 0.20 for growth traits. And most of the family-mean heritability values were above 0.50. In FARA, the selection strategy resulted in up to 26.37% genetic gain, while for TUNAS, it reached about 20%. GE effects are significant for volume. Because of the significant GE effects it is necessary to consider previous land use in the selection of genotypes for the formation of loblolly pine CSOs in the tested region. Considering the MHPRVG ranking, the maximum genetic gain estimated is 13.20%. The choice of more stable genotypes can circumvent the challenges imposed by crop rotation in the tested areas.

A Reevaluation of Superior Tree Performance After 48 Years for a Loblolly Pine Progeny Test in Southern Arkansas

A plus-tree progeny test of full- and half-sib “superior” loblolly pine (Pinus taeda) was installed in 1969 on the Crossett Experimental Forest (CEF) to consider the performance of 28 improved families with unimproved planting stock from the CEF (family W29). Performance was evaluated using data from young (3-year-old; early 1970s), maturing (25-year-old; 1994), and mature (48-year-old; 2017) trees. With the exception of a single improved family, early survival was high (>80%), with most families exceeding 90%. Three years post-planting, fusiform rust infection rates were also low, with most families having less than 1% of seedlings infected. At this early stage, the unimproved CEF family W29 only slightly underperformed the best full- and half-sib superior families. By 1994, W29 had slightly higher than average merchantable volume. This trend continued for W29 when remeasured in 2017, with the average merchantable volume yield for W29 statistically similar to the most productive families. This study found only limited volume performance gains from crossing plus-trees. However, it was important to note that several of the best height growth-performing families in 1972 were not the highest merchantable volume producers at 25 or 48 years, and some of the worst early performers moved into the upper tiers by the later remeasurements. These outcomes suggest that depending solely on early height performance to select families for long-term (>50 year) volume (especially if adjusted for wood density) or biomass yields may not be the best approach for forest managers seeking to increase carbon sequestration.

Evaluation of Long-Term Shortleaf Pine Progeny Tests in the Ouachita and Ozark National Forests, USA

Between the late 1970s and the early 1990s, the USDA Forest Service installed 155 shortleaf pine (Pinus echinata Mill.) progeny tests in national forests across the Southern Region of the United States. Using control-pollinated crosses from the Mount Ida Seed Orchard, 84 of these progeny tests were established in the Ouachita and Ozark-St. Francis National Forests in Arkansas and Oklahoma. Each of these 84 test locations had, on average, 33 full-sibling families representing three local geographic seed sources (East Ouachita, West Ouachita, and Ozark). Though largely abandoned years ago, the progeny tests that remain provided an opportunity to determine if significant genetic and genetic × environment variance exists for performance traits (d.b.h., tree height, and survival) decades after installation. In 2018 and 2019, we remeasured d.b.h. and height and determined survival in 15 fully stocked progeny tests. Family variances were significant (p < 0.01) for both d.b.h. and height but not for survival (p > 0.05). Seed sources differed significantly (p < 0.05) for d.b.h., with more pronounced latitudinal differences. Additionally, we determined that individual tree and full-sibling family mean heritabilities were moderate (0.15 and 0.72, respectively, for d.b.h and 0.09 and 0.41, for height), suggesting relatively high genetic to environmental variation and good potential for genetic improvement. We also found that shortleaf pine families were broadly adapted in this region since family-by-test variances were non-significant (p > 0.05).

Wood quality trait associations with climate: Room for improvement in two northern commercial tree species?

Climate driven tree mortality threatens the current performance and productivity of the temperate boreal forests. For economically important tree species, progeny trials provide an opportunity to assess variability in wood quality and growth traits and their associations with climatic stressors, such as water availability. Data from 3,152 34-year-old white spruce and lodgepole pine progeny, representing 120 half-sib families, were used to test the selective pressure of aridity on wood density and wood microfibril angle, two attributes that contribute to wood performance. Tree increment cores were further evaluated for correlations between time of transition out of juvenile wood production and the environment. Aridity at seed point of origin had minimal to no selective pressure on overall wood density or microfibril angle in the breeding populations represented in this study. Aridity at the progeny test sites had a greater effect on spruce wood density, however, similar effects on pine could not be assessed as sites were too climatically similar. Transition out of juvenile wood production was not found to be influenced by genetic differences across families in either species examined. These determinations are pivotal for breeding programs which seek to use heritable and economically important traits to select for adaptability in a changing climate.

Влияние хронического ионизирующего излучения на вариабельность митотической активности тканей Pinus sylvestris L.

The development of nuclear power engineering will increase in the future, due to the continued likelihood of radionuclides entering the environment. The relevance of studying the genetic material of conifers as a reliable bioindicator was revealed. It is known that under the influence of ionizing radiation there is an accumulation of genetic abnormalities in pine (Pinus sylvestris L.) progeny. The stages of gametogenesis, zygotes and young seedlings of plant organisms are most sensitive to ionizing radiation. It is important to determine the variability of the mitotic index (MI) of tissues of Scots pine (Pinus sylvestris L.) progeny in areas with different levels of ionizing radiation, including in the exclusion zone. The exposure dose rate was measured at the soil level and 1 m from the ground surface. Germination of seeds was carried out in a thermostat on wet filter paper. Roots of seedlings 0.5–1 cm long were fixed in a mixture of 96 % ethanol and glacial acetic acid. Root staining was carried out in a solution of acetocarmine. Tissue softening was carried out with a strong chloral hydrate solution. The total number of dividing cells, as well as pathological mitoses (PM) were counted on squash preparations using a microscope. The mitotic index and the duration of the phases of mitosis were determined. An increase in the level of radioactive contamination increases the cell division rate in prophase, anaphase, and telophase, but decreases the duration of metaphase, and also changes the relative duration of mitosis phases. With an increase in the exposure dose rate, the number of pathological mitoses naturally increases. The spectrum of mitosis disorders is represented by various abnormalities of the chromosome apparatus in anaphase: exit and lagging of chromosomes, bridges. Herewith, the number of anaphases with bridges increases significantly with simultaneous exit and lagging of chromosomes.

Frost hardiness of Scots pine progenies and some woody horticultural cultivars under different preconditioning

Frost hardiness of Scots pine progenies and some woody horticultural cultivars under different preconditioning

Application of growth traits and qualitative indices for selection of Scots pine (Pinus sylvestris l.) elite trees. A case study from Volyn region, western ukraine

Abstract Since the plus trees are selected based on phenotype, it is necessary to evaluate them in progeny test. The aim of this study is an indication of selecting elite mother trees based on the results from half-sib progeny test trials. As study sites, two Scots pine half-sib progeny tests were selected. During evaluation, the progenies had reached the age of 38 and 40 years, respectively. In both progeny trials, quantitative parameters and qualitative traits of Scots pine half-sib progenies were investigated. Based on these data, complex evaluation of half-sib families was carried out. We concluded that, Scots pine progenies at the age of 38 and 40 years in fresh and moist mixed forests are characterised by acceptable quality, with the survival being 25%–33% per progeny test trial. Based on a complex evaluation of 38- and 40-year-old half-sib progenies of plus trees, we proposed to select 31% of tested plus/mother trees as candidates for elite trees. Further, the list of candidates for elite trees was created with five plus trees from the Volyn region (26% of the total tested from the region) and four plus trees from the Lviv region (40% of the total tested from the region). With age, the share of the best and undesirable trees decreases, while the proportion of intermediate trees increases in both control trees and half-sib progenies. At the age of 38 and 40 years, the proportion of fast-growing offspring was from 0% to 36%, while the declining trend that was observed in previous years was being continued. Thus, due to the declining trend in the proportion of fast-growing offspring observed at the age of 38 and 40 years, we propose to select candidate trees for an elite group not early than after 40 years of test their progenies.

Long-Term Effect of Lophodermium Needle Cast on The Growth of Scots Pine and Implications for Financial Outcomes

In Northern Europe, climate change may facilitate the prevalence of Scots pine, yet also promote the spread of pathogens attacking this species. A common biotic risk for Scots pine in nurseries and young stands is Lophodermium needle cast, primarily caused by Lophodermium seditiosum, which negatively affects the survival and growth of saplings. Reduced tree growth has been observed several years after damage by Lophodermium needle cast. However, for decision-making in protection or resistance breeding, an estimate of financial loss is important. Thus, the study aimed to assess the long-term influence of Lophodermium needle cast on the growth and financial value of Scots pine stands. The effect of needle cast damage during the sixth growing season on growth at the age of 17 years was evaluated in a control-crossed Scots pine progeny trial, and the results indicated a significantly negative effect on the height and diameter of the trees. A significant family effect also existed on the severity of the needle cast damage. Long-term simulations indicated that severely damaged Scots pines had a reduced equivalent annual annuity (EAA) of almost 100% at the final harvest. More intensive early management to reduce stand density could partly compensate for losses caused by needle cast. A higher EAA for the most resistant group of trees regardless of the stand management scenarios suggests an economically justified potential for improved resistance. Strong negative (−0.62 to −0.70) correlations of height and survival with the proportion of severely affected trees at the family mean level implies that resistant genotypes can be selected along with improved growth in progeny trials, which are affected by needle cast.

GENETIC AND BREEDING ASSESSMENT OF SCOTS PINE PLUS TREES IN KARELIA

Growth and survival of 123 grafted and half-sib Scots pine (Pinus sylvestris L.) progenies have been investigated in a 1st generation seed orchard and progeny tests of various ages. It was found that during the first decade after planting the survival rate of the progeny tests was going slightly down, with a simultaneous decrease in the share of progenies superior to the control, and in the degree of superiority (height difference). We observed a moderate statistically significant correlation between the heights of maternal clones and their half-sib progenies, with its positive trend (from r = 0.28 in 2014 up to r = 0.33 in 2018) during the entire study period. Older progeny tests (30 years old) showed a moderate significant correlation (r = 0.36) in the ratio of stem faults (forked, multistem) between clones and half-sib progenies. It was confirmed that selection based on growth rate should have the highest priority for Scots pine plus trees provided that the habit and seed productivity of their clones are taken into account. The results reported here testify to the statement that reliable preliminary assessments of half-sib families can be obtained starting at the age of 7, with the tests lasting 25–30 years at maximum. As a result of the breeding and selection assessment, a set of 20 plus trees (clones) had been formed fulfilling minimum requirements for an advanced-value seed orchard of the I,5 generation.

Resistance of Scots pine half-sib families to <i>Heterobasidion annosum</i> in progeny field trials

Five Scots pine ( L.) progeny field trials, each established in different Lithuanian regions of provenance in 1983, were studied. Each progeny field trial consists of 140 half-sib families from seven populations (20 families from each population). The evaluation was carried out in 2012 and 2018 to assess the families resistance to (Fr.) Bref. An index of resistance in the infected plots was calculated. To verify the accuracy of the method, total phenolic compounds (TPC) was chosen as key parameter to compare with the plant resistance index. During the six years between the two assessments, the percentage of living Scots pine trees in the progeny field trials decreased up to 20 percentage points (range: 4 p.p. to 20 p.p.). In 2018 the area of damaged plots (in percentage from total field trial area) varied from 17 to 27%. Tree mortality in the trial correlates with site soil fertility – more fertile soils were distinguished by higher tree percentage loss and . Using analysis from combined data of all progeny trials, the family variance component reached 13.3 ± 2.2% and family heritability was 0.81. Family heritability estimates for root rot resistance show possibilities of high breeding effectiveness. The correlations between the trials in family resistance estimates were negligible (ranging from 0 to 0.28). The significant high correlation coefficient was determined between the resistance index and TPC concentration ( = 0.77,  = 0.0003). This allows us to assume that plant resistance is directly linked on TPC synthesis. The results indicate that the chosen methods of chemical resistance for identification of root rot-resistant genotypes are applicable for the selection of Scots pine half-sib families in the field trials with higher resistance to pathogens.Pinus sylvestrisHeterobasidion annosumH. annosumvice versarp

Genotypic variation in the basic density, dynamic modulus of elasticity and tracheid traits of Pinus elliottii in three progeny trials in southern China

Abstract A firm understanding of the genetic relationships among wood properties is a prerequisite for breeding for higher wood quality in Pinus elliottii families. To examine and deal with such relationships, increment cores were sampled at breast height from 1260 trees in 42 open-pollinated families in three 27-year-old Slash pine progeny trials in southern China, and genetic variation, genotype-by-environment (G × E) interaction, genetic correlation and correlated response were investigated. The basic density (BD), dynamic modulus of elasticity (MOED) and tracheid traits were found to be under moderate to strong genetic control for the three locations combined, with individual narrow-sense and family mean heritability ranging from 0.28 to 0.44 and 0.52 to 0.69, respectively. Type B genetic correlation estimates indicated that the G × E interaction had a small-level influence on wood properties. Strong genetic correlations (rg) were found between BD and MOED at the three sites (rg = 0.46–0.85), and BD or MOED showed moderate to strong correlations with most tracheid traits at specific localities. In tree breeding programs, one possible strategy would be to improve pulpwood quality and the strength of structural wood through selection for different wood quality traits.

Изменчивость вегетативного потомства плюсовых деревьев кедра сибирского, аттестованных по стволовой или семенной продуктивности

Siberian pine (Pinus sibirica Du Tour) is a tree species differences by the diversity of valuable properties. Considering its value and reduction of its growing stock due to forest fires, death from silkworm and illegal logging, it is necessary to preserve and multiply the leading species, which were formed in vivo. The results of studying the Siberian pine in the conditions of the Southern Siberian mountainous forest site zone are presented. The research purpose is the study of variability of Siberian pine progeny on the trial plot. Plus trees certified in Novosibirsk region for seed and stem productivity were taken as parent trees. Plus trees had a height of 16.0–30.5 m and trunk diameter of 44–78 cm. The average number of cones on trees for a 10-year period before certification (1967–1977) was 203–470 pcs. Plus trees (35) certified in 1977 for stem (17 trees) and seed productivity (18 trees) were selected for the study. Their parameters were compared with the clone progeny at the scion’s age of 29 years. The following biometric parameters of ramets of different clones were determined: height of stem, diameter and volume of stem and crown; length of needles; cones formation regardless of plus trees certification for stem or seed productivity. Clonal planting materialwas grown by grafting of Siberian pine to the 6-year-old seedlings in spring of 1989. The seedling’ age was 8 years (scion – 6 years, rootstock – 2 years) when they were planted on a plantation. In subsequent years, variability of clone progeny parameters was observed. It was found that the biometric parameters and percentage of trees that formed cones had no significant differences in comparison of progeny of plus trees certified for both seed and stem productivity. The average number of cones in ramets of plus trees was significantly different by seed productivity. A large variability of parameters was observed among the clones and ramets in clones regardless of the purpose of selection in certification of parent trees. The heritability coefficient of parent trees was 40.7 % in height of clonal progeny, and 35.0 % in stem diameter. The individual ramets differ by growth intensity, seed and environmental productivity were selected. The obtained results can be used in the creation of the second generation clone plantations of increased genetic value in the conditions of the Southern Siberian mountainous forest site zone.For citation: Narzyaev V.V., Matveeva R.N., Butorova O.F., Shcherba Yu.E. Variability of Vegetative Progeny of Siberian Pine Plus Trees Certified for Stem or Seed Productivity. Lesnoy Zhurnal [Forestry Journal], 2019, no. 4, pp. 22–33. DOI: 10.17238/issn0536-1036.2019.4.22

Genotype-by-environment interactions and the dynamic relationship between tree vitality and height in northern Pinus sylvestris

Tree health and growth rate must both be considered in Scots pine breeding for harsh areas such as northern Sweden. Univariate (UV) and multivariate (MV) multi-environment trial (MET) analyses of tree vitality (a measure of tree health) and height (a measure of growth rate) were conducted for four series of open-pollinated Scots pine progeny trials (20 trials total), to evaluate age trends, patterns, and drivers of genotype-by-environment interaction (G × E). The lowest standard errors were obtained for the MV MET analyses, indicating that MV analyses are preferable to UV analyses. By incorporating factor-analytic structures, the most complex data sets could be handled, suggesting that factor-analytic analyses are preferred for evaluation of forest progeny trials. We detected strong patterns of G × E for both tree vitality and height, and the driver of G × E was found mainly to be differences in degree day temperature sum, such that G × E was higher between trials with more contrasting temperature sums. The genetic correlations, between vitality and height within sites, were generally positive and were driven by the harshness of the trial; mild trials had lower genetic correlations than did harsh trials. The sign of the across-site genetic correlations between vitality and height changed from positive to negative in some cases, as the differences between the temperature sum of the trials increased. These findings support the hypothesis that tree height assessed in harsh environments with low survival is likely to reflect health and survival ability to a greater extent than growth capacity.

Estimation of genetic parameters, provenance performances, and genotype by environment interactions for growth and stiffness in lodgepole pine (Pinus contorta)

ABSTRACTGenetic parameters, performance of provenances, and genotype by environment interaction (G × E) for diameter at breast height (DBH), survival, and modulus of elasticity of time-of-flight (MOEtof) (an indirect measure of stiffness), were investigated in six lodgepole pine progeny trials, aged 33–36 years, within three breeding zones in northern Sweden. Provenances of Yukon origin had the highest growth but lowest stiffness at higher latitude, while those of British Columbia (BC) origin grew faster at lower latitudes and had highest stiffness within zone 5. Combined-site heritability estimates ranged from 0.09 to 0.19 for DBH, from 0.19 to 0.27 for MOEtof, and from 0.13 to 0.26 for survival. Type-B genetic correlations () were generally high for all studied traits, except for DBH and survival in zone 4 ( = 0.74 and 0.40, respectively) and for MOEtof in zone 2 ( = 0.46). On the basis of the results obtained in this study, G × E for stiffness in northern Sweden and unfavourable growth-stiffness genetic correlation should be considered in selective breeding programmes of lodgepole pine. To achieve the highest stiffness for lodgepole pine, provenances of Yukon origin should be planted at lower latitudes and those of BC origin should be planted at lower elevations within the tested breeding zones.

A COMPREHENSIVE ASSESSMENT OF CANDIDATES TO SYNTHETIC VARIETY-POPULATIONS IN THE SCOTS PINE VARIETY TESTS IN GUTYANSKE FOREST ENTERPRISE

The article presents the results of the examination of Scots pine progenies from nine clonal seed orchards (CSO) and one permanent forest seed stand (PFSS), which were potential synthetic variety-populations, as well as of their regional control variants (Kharkiv, Kyiv, Rivne and Volyn regions). All the progenies were tested in the Gutyanske Forest Enterprise in Kharkiv region. Mensuration and breeding indicators and state and level of resin productivity were estimated. At the age of 20, three out of ten potential variety-populations exceeded local control by the heights and diameters. The variants from the eastern and central regions were better than western ones by the breeding structure and state category. Only one candidate to the variety-population exceeded local control by the level of resin productivity, the rest ones were somewhat lower. In seven variants, the proportion of trees with higher resistance to phytopathology, in particular, to the annosum root rot, were higher (Pst = 45…50 %) than in the control (Pst = 40 %). The correlation between the resin productivity and the growth characteristics were weak (for diameter, r = 0,32 ± 0,055; for height, r = 0,17 ± 0,057). The results of integrated point assessment of candidates to variety-populations indicated the feasibility of using seeds from CSO and PFSS to create Scots pine stands to be potentially resistant to phytopathogenic diseases.

Genetic control of transition from juvenile to mature wood with respect to microfibril angle in Norway spruce (Picea abies) and lodgepole pine (Pinus contorta)

Genetic control of microfibril angle (MFA) transition from juvenile wood to mature wood was evaluated in Norway spruce (Picea abies (L.) Karst) and lodgepole pine (Pinus contorta Douglas ex Loudon). Increment cores were collected at breast height (1.3 m) from 5664 trees in two 21-year-old Norway spruce progeny trials in southern Sweden and from 823 trees in two lodgepole pine progeny trials, aged 34–35 years, in northern Sweden. Radial variations in MFA from pith to bark were measured for each core using SilviScan. To estimate MFA transition from juvenile wood to mature wood, a threshold level of MFA 20° was considered, and six different regression functions were fitted to the MFA profile of each tree after exclusion of outliers, following three steps. The narrow-sense heritability estimates (h2) obtained for MFA transition were highest based on the slope function, ranging from 0.21 to 0.23 for Norway spruce and from 0.34 to 0.53 for lodgepole pine, while h2 were mostly non-significant based on the logistic function, under all exclusion methods. Results of this study indicate that it is possible to select for an earlier MFA transition from juvenile wood to mature wood in Norway spruce and lodgepole pine selective breeding programs, as the genetic gains (ΔG) obtained in direct selection of this trait were very high in both species.

Postglacial migration and adaptation for dispersal in pitch pine (Pinaceae).

Variation in a species is a blend of adaptive, random, and migratory responses. Pitch pine (Pinus rigida), a highly variable eastern conifer, has occupied multiple glacial refugia, whose harsh conditions favored adaptations enhancing subsequent dispersal and recolonization of newly deglaciated sites. We assessed phenotypic diversity in long-term growth trials to elucidate both the adaptations and likely refugia. Pitch pine progeny from 31 areas were grown in common gardens in six locations, from eastern Massachusetts to Korea. Survival increased with source latitude, but seedlings from southern latitudes were tallest in the first (postplanting) year, but that advantage dissipated in later years. Progeny from northern latitudes were precocious, highly fecund, had smaller seeds, and more seeds per cone. Seed mass decreased with latitude in both parents and progeny. Serotinous cones were notably common in the New Jersey Pine Plains and Acadia National Park. Various disease agents and frost burn exhibited latitudinal trends that were nonlinear, with a break in the regression slope at about 40°N latitude. Cluster analysis identified both northern and southern groups, largely split between unglaciated and deglaciated terrain, but with Acadia and the Pine Plains as unique outliers. Within the southern group, provenances were organized into contiguous subgroups, but geographic structure was less evident in the northern group. The present range of pitch pine was colonized by migrants from at least three different refugia, including at least one on the exposed continental shelf during the Last Glacial Maximum.

A novel individual-tree mixed model to account for competition and environmental heterogeneity: a Bayesian approach

Negative correlation caused by competition among individuals and positive spatial correlation due to environmental heterogeneity may lead to biases in estimating genetic parameters and predicting breeding values (BVs) from forest genetic trials. Former models dealing with competition and environmental heterogeneity did not account for the additive relationships among trees or for the full spatial covariance. This paper extends an individual-tree mixed model with direct additive genetic, genetic, and environmental competition effects, by incorporating a two-dimensional smoothing surface to account for complex patterns of environmental heterogeneity (competition + spatial model (CSM)). We illustrate the proposed model using simulated and real data from a loblolly pine progeny trial. The CSM was compared with three reduced individual-tree mixed models using a real dataset, while simulations comprised only CSM versus true-parameters comparisons. Dispersion parameters were estimated using Bayesian techniques via Gibbs sampling. Simulation results showed that the CSM yielded posterior mean estimates of variance components with slight or negligible biases in the studied scenarios, except for the permanent environment variance. The worst performance of the simulated CSM was under a scenario with weak competition effects and small-scale environmental heterogeneity. When analyzing real data, the CSM yielded a lower value of the deviance information criterion than the reduced models. Moreover, although correlations between predicted BVs calculated from CSM and from a standard model with block effects and direct genetic effects only were high, the ranking among the top 5 % ranked individuals showed differences which indicated that the two models will have quite different genotype selections for the next cycle of breeding.