Variation In Height Growth Research Articles

Relational Composition between Periodic Fluctuation and Seasonal Variation in Height Growth

Relational Composition between Periodic Fluctuation and Seasonal Variation in Height Growth

Combining Climatic and Genomic Data Improves Range-Wide Tree Height Growth Prediction in a Forest Tree.

AbstractPopulation response functions based on climatic and phenotypic data from common gardens have long been the gold standard for predicting quantitative trait variation in new environments. However, prediction accuracy might be enhanced by incorporating genomic information that captures the neutral and adaptive processes behind intrapopulation genetic variation. We used five clonal common gardens containing 34 provenances (523 genotypes) of maritime pine (Pinus pinaster Aiton) to determine whether models combining climatic and genomic data capture the underlying drivers of height growth variation and thus improve predictions at large geographical scales. The plastic component explained most of the height growth variation, probably resulting from population responses to multiple environmental factors. The genetic component stemmed mainly from climate adaptation and the distinct demographic and selective histories of the different maritime pine gene pools. Models combining climate of origin and gene pool of the provenances as well as height-associated positive-effect alleles (PEAs) captured most of the genetic component of height growth and better predicted new provenances compared with the climate-based population response functions. Regionally selected PEAs were better predictors than globally selected PEAs, showing high predictive ability in some environments even when included alone in the models. These results are therefore promising for the future use of genome-based prediction of quantitative traits.

Weather-sensitive height growth modelling of Norway spruce using repeated airborne laser scanning data

Fluctuations in weather conditions, particularly precipitation and water availability, may strongly affect growth rate patterns and lead to interannual height growth variation. Consequently, height growth models developed using airborne laser scanning (ALS) data collected at short time intervals may over- or underestimate long-term height growth trends and finally result in different growth forecasts. The objective of this study was to develop height growth models for Norway spruce, including the effect of weather conditions. We used ALS-derived top height (TH) estimates and meteorological data from the research area collected for 2007-2012 and 2013-2018 to develop a weather-sensitive height growth model. The top height (TH) growth of Norway spruce was affected by the mean annual precipitation sum (APS) in the studied periods, and a higher APS resulted in faster TH growth. This study demonstrates the high potential of repeated ALS for detecting short-term variation in the tree height increment and the development of weather-sensitive height growth models.

The variation regularity on seedling growth of Phellodendron amurense in different germplasm resources and families

The height growth variation of Phellodendron amurense was analyzed. The studied materials are two years old seedlings in Qing Mountain forestry center of Linkou county. The study shows that there are rich variations within the different germplasm resources. The variation parameter fluctuates among germplasm resources is from 20.10%~ 31.2%. The height growth of the different germplasm resources reaches the extreme marked level, the height in the germplasm resources of Xinglong, Fangzheng and Yingchun are the fastest, medium in Qingshan and Weihe, and the lowest in Jiayin germplasm resources. The height growth of the Xinglong germplasm resources is faster 56.5% than that of Jiayin. There are rich variations within the Xinglong germplasm resources, the variation coefficient is 14.4%~ 23.4%, the average value is 18.6%. The differences between seedling height of families reach the extreme marked level. There are rich variations within the Jiayin germplasm resources and families. the variation coefficient is 12.7%~ 31.0%, the average value is 21.9%. The differences between seedling height growth of families reach reach the extreme marked level. The three families is faster 56.6% than the lower families in the height growth. Jia-6 is faster 75.4% than Jia-11.

Assessing the relationship between height growth and molecular genetic variation in Douglas-fir (Pseudotsuga menziesii) provenances

Douglas-fir (Pseudotsuga menziesii) is a conifer tree native to western North America. In central Europe, it shows superior growth performance and is considered a suitable substitute for tree species impaired in vitality due to climate change. Maintenance and improvement of growth performance in a changing environment is a main challenge for forest tree breeders. In this context, genetic variation as a factor underlying phenotypic variation, but also as the basis for future adaptation, is of particular interest. The aims of this study were to analyse (1) genetic diversity of selected Douglas-fir provenances, (2) variation in height growth among provenances, and (3) to assess the link between genetic and phenotypic variation in height growth. Genotyping was done on microsatellite loci. Effects of ‘provenance’, ‘genotype’, and ‘site’ on height growth were assessed by fitting mixed linear models. The most significant genetic differentiation was observed between provenances of the coastal variety, versus a provenance of the interior variety originating from British Columbia. Although genetic differentiation among provenances of the coastal variety was lower, genetic structures within this variety were identified. Moreover, genetic diversity showed a latitudinal gradient with the southernmost provenances being more diverse, probably reflecting the species’ evolutionary history. The modelling approach revealed that height growth differed significantly by ‘provenance’, ‘site’, and the interaction between ‘site’ and ‘provenance’. Additionally, this analysis showed that genetic variation captured by the genotyped microsatellite loci was significantly related to variation in height growth, providing statistical evidence for a genetic component in the observed phenotypic variation.

Post-harvest height growth of Norway spruce seedlings in northern Finland peatland forest canopy gaps and comparison to partial and complete canopy removals and plantations

Recent studies have shown the establishment of Norway spruce ( (L.) Karst.) to be successful in small canopy gaps cut in drained spruce mire stands in northern Finland. The aim of this study was to quantify seedling height growth in gaps and compare it to that observed in other canopy cuttings and plantations. We sampled spruce crop seedlings (maximum density ca. 3000 ha) in the spring of 2013 in a field experiment in which canopy gaps of 10, 15 and 20 m in diameter had been cut in winter 2004. The total seedling height in 2013 and the length of annual shoots over the past five years (2012–2008) were recorded in the survey. Seedling height varied from 20 cm to 2.7 m, with an average of 65 cm. The average annual height growth was 7.1 cm. A mixed linear model analysis was carried out to investigate seedling height growth variation. Seedling height was linearly and positively related to growth. Height growth started to increase in the fifth growing season after cutting. Seedling height growth in the 20 m gap was slightly better than in the smaller ones. In the 15 m gap, both the centrally located seedlings and those located at the northern edge grew best. In the 20 m gap, southerly located seedlings grew more slowly than seedlings in all other locations. The average seedling height growth in this study was about 60% of that in peatland plantations, but comparable to that in mineral soil gaps, and 2–3 times higher than in uneven-age cut stands.Picea abies–1

Phenological variation in height growth and needle unfolding of Smith fir along an altitudinal gradient on the southeastern Tibetan Plateau

Little is known about variations in tree phenology and their driving forces on the Tibetan Plateau. Herein, we monitored shoot growth and needle unfolding of Smith fir (Abies georgei var. smithii) between 3,800 and 4,360 m a.s.l. in the Sygera Mountains, southeastern Tibetan Plateau. The trees were 0.45–1.48 m high and 12–39 years old. Their phenology was observed every week between May 5 and August 26, 2011. With increasing elevation, shoot growth and needle unfolding started increasingly later, thus indicating a thermal driving force. Although the weekly shoot increment was decreasing with increasing elevation, height growth at various elevations ended in the same week, implying other factors than temperature being responsible for the end of height growth. The accumulated heat sum for the onset of shoot growth appeared to be lower between 4,200 and 4,360 m than between 3,800 and 4,000 m. The anticipated spring warming will likely induce an earlier onset of shoot growth, whereas shoot growth will apparently not benefit from autumn warming. However, the lack of long-term data records precluded a robust statistical test of the underlying cause-and-effect relationships involved in the phenological variations of height growth and needle unfolding.

A stand dynamic model for red pine plantations with different initial densities

A stand dynamic model was developed to predict the growth response in even-aged forest plantations of different initial planting densities. The model is based on the integration of three subcomponents: height growth, self-thinning, and diameter increment. The integrated model uses the height of dominant trees to simulate stand response to site quality and internal growth potential. An extended self-thinning submodel is used to simulate mortality in stands due to crowding and inter-tree competition. A diameter increment submodel is used to link the height growth and self-thinning submodels. The height growth submodel is based on an application of the “Pipe Model” theory. The three-parameter self-thinning submodel is developed from an extended self-thinning law that captures self-thinning in stands before they attain full stocking. The diameter increment model is based on the assumption that diameter increment is related to height growth and available growing space described by stand density. The integrated model is applied to data collected from a 45-year-old red pine (Pinus resinosa Ait.) plantation subsectioned with different initial planting densities. For the data used, only two parameters were required to capture 99% of measured variation in height growth. Additional data from sites with different planting intensities are required to formulate a more generalized height growth model. The slope of the linear self-thinning limit for red pine is approximately −1.5. Model predictions are consistent with field measurements.

Clonal propagation of guava (Psidium guajava Linn.) by stem cutting from mature stockplants

The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the non-mist propagator. Rooted cuttings were allowed to grow in the polybags filled with soil and cow-dung mixed in the ratio of 3: 1 (by volume) for three months to assess the steckling capacity and initial growth performance. The study reveals that the species is amenable for clonal propagation by mature stem cutting. The highest rooting percentage (60%) was observed in the cuttings treated with 0.4% IBA solution followed by 0.2% IBA and the lowest was in controlled cuttings. The maximum number of primary root (32.7) was developed in the cuttings treated with 0.8% IBA solution followed by 0.4% IBA and the lowest was in the cuttings without IBA treatment. The highest survival percentage (70.9) was observed in the cuttings rooted with 0.4% IBA treatment and the lowest (58.3) was in the cuttings without any treatment. However, there was no significant variation in height growth of cutlings due to IBA treatments in rooting.

Leaf Traits Determine the Growth‐Survival Trade‐Off across Rain Forest Tree Species

A dominant hypothesis explaining tree species coexistence in tropical forest is that trade-offs in characters allow species to adapt to different light environments, but tests for this hypothesis are scarce. This study is the first that uses a theoretical plant growth model to link leaf trade-offs to whole-plant performances and to differential performances across species in different light environments. Using data of 50 sympatric tree species from a Bolivian rain forest, we observed that specific leaf area and photosynthetic capacity codetermined interspecific height growth variation in a forest gap; that leaf survival rate determined the variation in plant survival rate under a closed canopy; that predicted height growth and plant survival rate matched field observations; and that fast-growing species had low survival rates for both field and predicted values. These results show how leaf trade-offs influence differential tree performance and tree species' coexistence in a heterogeneous light environment.

Dynamics of daily height growth in Scots pine trees at elevated temperature and CO2

The aim of this study was to analyse and model the effects of elevated temperature and carbon dioxide concentration on daily height growth of 20-year-old Scots pines (Pinus sylvestris L.). The trees were grown with a low nitrogen supply in closed chambers with a factorial combination of two temperature regimes (ambient and elevated) and two carbon dioxide concentrations (ambient and twice ambient). The temperature elevation corresponded to the predicted increase at the site after a doubling in atmospheric CO2. The height growth of Scots pines was first empirically studied in terms of its onset, cessation and duration, and the allocation of daily height growth within the growing period in 2000 and 2001, and then a model predicting daily height growth as a function of daily temperature and temperature sum was developed. The empirical results showed elevated temperature to be the dominant variable explaining variation in daily height growth. Elevated temperature also hastened both the onset and cessation of height growth, and the temperature sums for both of them were higher in the elevated than in the ambient temperature treatments. The daily variation in height growth could also be explained by the daily mean temperature in the model. Elevated CO2 concentration had no effect on the onset, cessation or duration of height growth. The amount of height growth was not affected by any of the treatments.

Geographic variation and genetic performance ofPicea koraiensis in growth and wood characteristics

Eight provenances of 19-year-old Picea koraiensis Nakai from the provenance trials of Maoershan (45°20'N, 127°30'E), Liangshui (47°10'N, 128°53'E) and Jiagedaqi (50°24'N, 124°07'E) in Northeast China were investigated to analyze the genetic variation in growth characteristics (tree height and diameter) and wood characteristics (tracheid length, tracheid diameter, tracheid wall thickness, annual ring width as well as wood density). Great variation in height growth and breast height diameter growth was observed among the provenances, and along with the increase of tree age, these provenances presented different geographic adaptability. The growth characteristics of Picea koraiensis stand at age of 10 in Maoershan and Liangshui provenance trials had a positive correlation with longitude, and with increase of tree age to 15 and 19, the tree growth of the provenances displayed a significant positive correlation with latitude as well as altitude. For wood characteristics, great variation was also found among the provenances. There exists a close relation between growth characteristics and wood properties of the provenance. The height and breast height diameter growth of the provenance had a positive correlation with tracheid diameter and annual ring width, and a negative correlation with tracheid wall thickness and wood density. Genetic performance of the provenance in all above characteristics was also investigated in order to provide more useful information for comprehensive selection of this species for pulpwood and plywood production.

Multilevel modelling of height growth in young Norway spruce plantations in southern Finland

Height development of Norway spruce (Picea abies (L.) Karst.) transplants was studied on 22 sites prepared by disc trenching or mounding. At the age of 4–9 years the plantations were surveyed using a multistage sampling design. For every planted spruce on a plot, the past annual height increments were measured as far into the past as possible. Multilevel mixed linear modelling was used to analyse the variation in growth at different levels (year, stand, cluster, plot, tree) and the effects of climatic and site characteristics on height growth. The within-plantation variation in height growth was higher on mounded sites than on disc-trenched sites. The mean temperature and the precipitation sum of the summer months affected height growth positively. Soil characteristics measured from undisturbed soil did not explain the height growth of seedlings on mounded sites, whereas on disc-trenched sites, the depth of the organic layer and the soil temperature had a positive effect and the depth of the eluvial horizon a negative effect. The modelling approach used proved to be a useful method for examining the sources of variation in development of young plantations.

Effect of harvest intensity on development of natural regeneration and shrubs in an Ontario boreal mixedwood stand

Resource managers in northern Ontario need guidelines for establishing productive species mixtures and maintaining a viable conifer component through natural regeneration on upland boreal mixedwood (BMW) sites. The hypothesis that partial cutting favours conifers by inhibiting development of hardwood reproduction and associated competitors was tested. Harvesting to nominal basal area (BA) reductions of 0, 36, 68, and 100% was conducted in a northeastern Ontario mixedwood stand dominated by trembling aspen ( Populus tremuloides Michx.) in the overstory and balsam fir ( Abies balsamea [L.] Mill.) and shrubs in the understory. A positive linear relationship existed between photosynthetically active radiation (PAR) transmittance and initial BA reduction at 1, 3, and 5 years after harvesting. However, the relationship weakened over the 4-year period. Although BA reduction level did not account for significant variation in height growth of conifer advance regeneration, it explained 31% of the variation in conifer sapling diameter growth, 61% of the variation in hardwood regeneration height growth, and 21% of the variation in shrub height growth. Based on post-harvest height comparisons among conifers, hardwoods, and shrubs, partial cutting to promote conifer advance regeneration on BMW sites cannot be recommended. Maintaining a viable understory of shade-tolerant conifers for the next rotation may be more feasible than promoting conifer–hardwood overstories in the current rotation. The increase in sapling growth with BA reduction level implies that the entire overstory should be removed if the site is adequately stocked with conifer saplings. Similarly, harvesting should remove the entire overstory if the objective is to maximize growth of hardwood regeneration. Clearcutting promoted growth of both hardwood crop trees and shrubs, but hardwoods remained dominant after 5 years. Height development patterns indicate that regeneration and competitors should be monitored long enough following harvesting to determine whether additional interventions may be necessary to achieve stand structure objectives. Further studies are required to investigate the effects of other factors on advance regeneration, such as pattern and season of harvest and degree of soil disturbance.

Effect of harvest intensity on development of natural regeneration and shrubs in an Ontario boreal mixedwood stand

Resource managers in northern Ontario need guidelines for establishing productive species mixtures and maintaining a viable conifer component through natural regeneration on upland boreal mixedwood (BMW) sites. The hypothesis that partial cutting favours conifers by inhibiting development of hardwood reproduction and associated competitors was tested. Harvesting to nominal basal area (BA) reductions of 0, 36, 68, and 100% was conducted in a northeastern Ontario mixedwood stand dominated by trembling aspen ( Populus tremuloides Michx.) in the overstory and balsam fir ( Abies balsamea [L.] Mill.) and shrubs in the understory. A positive linear relationship existed between photosynthetically active radiation (PAR) transmittance and initial BA reduction at 1, 3, and 5 years after harvesting. However, the relationship weakened over the 4-year period. Although BA reduction level did not account for significant variation in height growth of conifer advance regeneration, it explained 31% of the variation in conifer sapling diameter growth, 61% of the variation in hardwood regeneration height growth, and 21% of the variation in shrub height growth. Based on post-harvest height comparisons among conifers, hardwoods, and shrubs, partial cutting to promote conifer advance regeneration on BMW sites cannot be recommended. Maintaining a viable understory of shade-tolerant conifers for the next rotation may be more feasible than promoting conifer–hardwood overstories in the current rotation. The increase in sapling growth with BA reduction level implies that the entire overstory should be removed if the site is adequately stocked with conifer saplings. Similarly, harvesting should remove the entire overstory if the objective is to maximize growth of hardwood regeneration. Clearcutting promoted growth of both hardwood crop trees and shrubs, but hardwoods remained dominant after 5 years. Height development patterns indicate that regeneration and competitors should be monitored long enough following harvesting to determine whether additional interventions may be necessary to achieve stand structure objectives. Further studies are required to investigate the effects of other factors on advance regeneration, such as pattern and season of harvest and degree of soil disturbance.

Family differences in height growth and photosynthetic traits in three conifers.

We investigated variation in height growth, gas exchange, chlorophyll fluorescence and leaf stable carbon isotope ratio among wind-pollinated progenies of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca), ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and western white pine (Pinus monticola Dougl. ex D. Don) from a small group of contiguous stands on the Priest River Experimental Forest in northern Idaho. Photosynthetic variables differed between height classes in the pines, but not in Douglas-fir. Among species and families, tall families of ponderosa pine regained photosynthetic capacity earliest in the spring and maintained it latest in the growing season. Tall families of western white pine had higher instantaneous water-use efficiencies and lower photosynthetic rates than short families on warm days in August.

Evaluation of major genetic loci contributing to inbreeding depression for survival and early growth in a selfed family of Pinus taeda.

The magnitude of fitness effects at genetic loci causing inbreeding depression at various life stages has been an important question in plant evolution. We used genetic mapping in a selfed family of loblolly pine (Pinus taeda L.) to gain insights on inbreeding depression for early growth and viability. Two quantitative trait loci (QTLs) were identified that explain much of the phenotypic variation in height growth through age 3 and may account for more than 13% inbreeding depression in this family. One of these QTLs maps to the location of cad-nl, a lignin biosynthesis mutation. Both QTLs show evidence of overdominance, although evidence for true versus pseudo-overdominance is inconclusive. Evidence of directional dominance for height growth was noted throughout the genome, suggesting that additional loci may contribute to inbreeding depression. A chlorophyll-deficiency mutation, spf did not appear to be associated with growth effects, but had significant effects on survival through age 3. Previously identified embryonic viability loci had little or no overall effect on germination, survival, or growth. Our results challenge, at least in part, the prevailing hypothesis that inbreeding depression for growth is due to alleles of small effect. However, our data support predictions that loci affecting inbreeding depression are largely stage specific.

Genotype×environment interactions in Alnus rubra: developing seed zones and seed-transfer guidelines with spatial statistics and GIS

Multiple provenance trials of red alder ( Alnus rubra Bong.) were used to demonstrate how geostatistical methods can be applied to develop better seed-transfer guidelines and seed-procurement zones for forestry. Height and survival of 65 provenances from British Columbia were measured at four test sites. Significant genotype × environment interactions were found at the population and family level. Provenances close to each planting site showed superior performance in growth and survival, suggesting adaptation of red alder to local environments. The environmental basis of local adaptations was evaluated using redundancy analysis. Geographic and climatic variates accounted for approximately equal amounts of the variation in height growth (21 and 23%, respectively), while geographic variates accounted for 60% of the variation in climatic variables. Loadings of the redundancy variates suggested that both, gene flow and selection by environmental factors shaped geographic patterns of genetic differentiation in red alder. Performance of seed sources at unknown locations was predicted with ordinary kriging throughout the natural range of red alder in British Columbia. General seed-transfer guidelines were then generated with principal component analysis of predicted reaction norms. We found clinal differentiation of reaction norms along the coast from northwest to southeast. Further, the Georgia depression was identified as an area of genetic differentiation. Based on predicted height and survival at two trials that most realistically represented operational planting sites, we derived simple rules for seed transfer. A transfer of 100 km in either direction along the coast was associated with a decline of 2.5% in survival, and ≈5 cm in 2-year height. Finally, we showed how maps of predicted performance and associated variance surfaces can be used to develop seed zones for specific objectives, where seed zones are given as maps of probabilities of a seed source performing above or below a given threshold for any combination of traits.

EVALUATION OF MAJOR GENETIC LOCI CONTRIBUTING TO INBREEDING DEPRESSION FOR SURVIVAL AND EARLY GROWTH IN A SELFED FAMILY OF PINUS TAEDA

The magnitude of fitness effects at genetic loci causing inbreeding depression at various life stages has been an important question in plant evolution. We used genetic mapping in a selfed family of loblolly pine (Pinus taeda L.) to gain insights on inbreeding depression for early growth and viability. Two quantitative trait loci (QTLs) were identified that explain much of the phenotypic variation in height growth through age 3 and may account for more than 13% inbreeding depression in this family. One of these QTLs maps to the location of cad-n1, a lignin biosynthesis mutation. Both QTLs show evidence of overdominance, although evidence for true versus pseudo-overdominance is inconclusive. Evidence of directional dominance for height growth was noted throughout the genome, suggesting that additional loci may contribute to inbreeding depression. A chlorophyll-deficiency mutation, spf, did not appear to be associated with growth effects, but had significant effects on survival through age 3. Previously identified embryonic viability loci had little or no overall effect on germination, survival, or growth. Our results challenge, at least in part, the prevailing hypothesis that inbreeding depression for growth is due to alleles of small effect. However, our data support predictions that loci affecting inbreeding depression are largely stage specific.Corresponding Editor: O. Savolainen

Genetic variation in host susceptibility to attack by the mahogany shoot borer, Hypsipyla grandella (Zeller)

Summary1 Attack by shoot borers (Hypsipyla grandella Zeller) is the main factor limiting the cultivation of Cedrela odorata and Swietenia macrophylla, two economically important members of the mahogany family. No viable methods of pest control are currently available. To assess for genetic variation in susceptibility to pest attack, a combined progeny/provenance test of C. odorata and a provenance test of S. macrophylla were established separately at CATIE, Turrialba, Costa Rica, and assessed intensively over an 84‐week period.2 Variation in height growth between provenances was highly significant in both species, provenance means varying by a factor of 2.7 and 1.2 in C. odorata and S. macrophylla, respectively. Cedrela odorata also displayed provenance variation in foliar phenology, as 94.7% of the trees from a ‘wet zone’ provenance remained foliated, whereas > 35% of trees from three ‘dry zone’ provenances abscised their leaves during the dry season.3 Both species displayed significant genetic variation in susceptibility to shoot borer attack. At the peak of attack during the second year of growth, the effect of provenance was highly significant in both species, the mean number of attacks per tree varying between 0.8–2.4 and 0.6–1.3 in different provenances of C. odorata and S. macrophylla, respectively. A provenance of C. odorata from San Carlos, Costa Rica, displayed consistently lower susceptibility to pest attack, being subjected to fewer attacks during the first year and demonstrating a higher mean height to first point of damage.4 The nitrogen, total tannin and proanthocyanidin concentration of foliage varied significantly between C. odorata provenances: nitrogen concentration was significantly lower and tannin and proanthocyanidin contents were significantly higher in trees from the San Carlos provenance, Costa Rica. This study therefore suggests that proanthocyanidins may reduce susceptibility of C. odorata to H. grandella, at least during the early period of growth.5 These results provide support for the development of plant resistance as a strategy for managing shoot borers. In particular, there may be scope for selecting for high foliar proanthocyanidin content and the ability to tolerate attack by vigorous apical growth.