Solid wood production of hybrid aspen requires relative longer rotation periods, thus increasing risk of wood damages by pests and diseases. We compared damages by heart rot and poplar borer of 48 ...years old hybrid (
Michx. ×
L.) and European aspen in a progeny trial located in Eastern part of Latvia. Trees were harvested and rot patches and galleries were recorded and measured at a stump level. The number of galleries had positive relation on number of patches and total area of rot. The susceptibility of the rot and poplar borer was similar for both hybrid and European aspen. Yet, some differences among families were detected. No effect of pathogens damage was observed on the tree growth. Larger trees had smaller proportion and incidence of rot and galleries per unit of area as well as wider outer rot-free wood layer.
Forest ecosystems provide a wide range of goods and benefits for human survival and well-being. This includes materials, food and fiber and other goods and benefits. Ecosystem services (ES) paradigm ...is increasingly used in socio-ecological studies. ES generally include provisioning services, regulation & maintenance services and cultural services. Identifying and mapping areas important for ES supply in peri-urban forested landscapes is crucial for comprehensive spatial planning process which takes into account the needs and preferences of local inhabitants. This is in contrast to planning approaches which have focused on which have been focused on mapping and valuing ES supply but ignoring ES demand. The aim of this study was to identify and assess the benefits provided by peri-urban forest ecosystems in two case study regions in Latvia. For this study, we chose two case study areas in Latvia: the city of Daugavpils and its surrounding district. Daugavpils district is located in South-eastern part of Latvia and covers 1876.1 km2. Population in Daugavpils district is 19,553, city of Daugavpils – 80,627. We used 238 structured interviews to collect data on local inhabitants’ preferences and views. Interviewer asked to rank 21 types of forest landscapes using printed photographs of which were linked to particular ES. Later we mapped co-occurrences of desirable types of forest landscapes (selected by >20% of respondents) using 1 × 1 km grid and identified Hot- and Cold-spots of ES supply using Getis-Ord GI* analysis in ArcGIS Pro. We found that more than 70% of respondents, both urban and rural, saw thinned deciduous forest and middle-aged pine forest landscape as important for their well-being. Respondents also did not rank highly regulation & maintenace ES but focused on cultural and provisioning ES. Hot-spot analysis indicated multiple, statistically significant (α = 0.01) clusters of ES supply which were located in large tracts of mainly production forests and few in protected forest areas with significant restrictions. Overall, our approach demonstrated that our approach for identifying and mapping co-occurrences of desirable forest landscapes can be useful for spatial planning at local and regional levels. This approach is based on needs and preferences of local inhabitants and provide the perspective more relevant to local communities compared to imposed top-down planning approaches.
•More than 70% of respondents, both urban and rural, saw managed forest landscapes as desirable.•Provisioning services such as mushrooms, wild berries and firewood was very important for rural respondents.•Respondents preferred forest landscapes which supply mainly provisioning and cultural services.•Ecosystem service supply Hot-spots were identified away from the city.
Conifers are long-lived and slow-evolving, thus requiring effective defences against their fast-evolving insect natural enemies. The copy number variation (CNV) of two key acetophenone biosynthesis ...genes Ugt5/Ugt5b and βglu-1 may provide a plausible mechanism underlying the constitutively variable defence in white spruce (Picea glauca) against its primary defoliator, spruce budworm. This study develops a long-insert sequence capture probe set (Picea_hung_p1.0) for quantifying copy number of βglu-1-like, Ugt5-like genes and single-copy genes on 38 Norway spruce (Picea abies) and 40 P. glauca individuals from eight and nine provenances across Europe and North America respectively. We developed local assemblies (Piabi_c1.0 and Pigla_c.1.0), full-length transcriptomes (PIAB_v1 and PIGL_v1), and gene models to characterise the diversity of βglu-1 and Ugt5 genes. We observed very large copy numbers of βglu-1, with up to 381 copies in a single P. glauca individual. We observed among-provenance CNV of βglu-1 in P. glauca but not P. abies. Ugt5b was predominantly single-copy in both species. This study generates critical hypotheses for testing the emergence and mechanism of extreme CNV, the dosage effect on phenotype, and the varying copy number of genes with the same pathway. We demonstrate new approaches to overcome experimental challenges in genomic research in conifer defences.
•Frost-related wood anomalies among the provenances of Scots pine were analysed.•Provenances had a significant effect on the occurrences of wood anomalies.•Provenance-by-trial interaction indicated ...plasticity of responses to cold events.•The occurrence of the frost-related wood anomalies decreased with age.•Higher continetality resulted in more frequent occurrence of wood anomalies.
Assisted gene flow is advised as one of the most effective means to sustain the productivity of forests under warming climate via application of the provenances (genotypes) capable to utilize longer vegetation season. Nevertheless in the temperate and boreal zones, the extension of vegetation period also subjects trees to effects of frosts, which can have severe economic impact under warming climate. In this study, wood anatomical anomalies related to late frosts in spring (‘frost’ rings) and early frosts in late summer (‘blue’ rings) for the eastern Baltic provenances of Scots pine (Pinus sylvestris L.) with a contrasting field performance were analysed retrospectively. Three trials with the age of 40 year in Latvia were sampled. The frost-related wood anomalies were identified using microscopy methods. Generalized mixed effects models were used to assess the effect of provenance on the probability of frost damage, accounting for the design of the trials, as well as for the inter-annual variability. The overall mean probability of frost-related wood anomalies was low (ca. 0.025), yet it increased with continentality of the trials, showing limited relation to the inter-annual variability of minimum temperatures. The probability of anomalies decreased with age. Provenance had a significant effect on the occurrence of ‘frost’ and ‘blue’ rings, implying genetically determined frost sensitivity, while the genotype (provenance) by environment (trial) interaction indicated high phenotypic plasticity of the trees. The probability of anomalies appeared related to the field performance of the provenances. The low-performing provenances (Dippoldiswalde and Eibenstock, which originated from the Orr Mountains) were most sensitive to frost, while the top-performing ones (Rytel and, particularly, Güstrow, which originated from coastal areas) showed only a few anomalies, indicating the linkage between frost sensitivity and growth. The local provenance, which showed an average field performance, also showed intermediate sensitivity to early frosts, thus supporting a necessity for the assisted gene flow in the eastern Baltic region.
In the Baltics, warming is expected to burden the growth of Norway spruce Picea abies, with weather anomalies/extremes having strong triggering effects, which can be mitigated by tree breeding. ...Within the region, breeding programmes have been aiming for productivity, yet being conservative, their sustainability depends on the adaptability of native genotypes, which is unclear. The adaptability of genotypes can be assessed through local adaptations and phenotypic plasticity, with the sensitivity of increment depicting the conformity of genotypes and environments. To assess the adaptability of native populations to anticipated climates, local genetic adaptation and phenotypic plasticity of the weather sensitivity of the radial increment were assessed by the methods of time series analysis and quantitative genetics based on three clonal trials (low-density single-tree plot plantations of grafted clones of native plus trees) representing the local climatic gradient in Latvia. The growth of trees was sensitive to the moisture availability in summer and the thermal regime in winter, yet coinciding anomalies in both were associated with abrupt changes in tree ring width. These environmental effects differed among the clones, indicating genetic controls over the sensitivity of increment, which, however, decreased under a warmer climate, suggesting a limited adaptability of local populations to warming. Still, the weather-growth relationships showed moderate phenotypic plasticity, suggesting some mid-term adaptability. Accordingly, supplementation of breeding populations via assisted gene transfer with the genotypes that are adapted to warmer and drier climates appears crucial.
•Wood anatomy of five Eastern European provenances of Scots pine was studied.•Tracheid proxies expressed significant provenance-by-trial interaction.•Top-performing provenances had tracheids with ...larger lumens and thinner walls.•Low-performing provenances formed smaller and thicker-walled tracheids.•Tracheids were affected by weather conditions prior and during their formation.
The efficiency of water use and transport are among the main factors affecting competitiveness, growth, and distribution of trees under warming climate. The phenotypical and genetic plasticity of tree populations is considered as an indicator of their adaptive capacity under changing environment. Climatic changes are expected to affect growth of Scots pine (Pinus sylvestris L.), and selection of reproductive material among the populations suitable for future climates has been advised for sustaining productivity of stands. In this regard, provenance trials can serve as source of comprehensive information about growth plasticity and climate-growth interactions of diverse populations. Quantitative wood anatomy can provide detailed information about xylogenesis and factors affecting it, which are crucial for long-term predictions. Wood anatomy of two top- (Gustrow and Rytel), two low-performing (Eibenstock and Dippoldiswalde), and one local (Kalsnava) provenances of Scots pine from the eastern Baltic region growing in three provenance trials in Latvia was studied using mixed models, accounting for the experimental design, as well as using the time-series approach. Provenance had a significant effect on the studied wood anatomical proxies, indicating genetic adaptation of xylogenesis. The top-performing provenances, which originated from warmer and drier conditions, had tracheids with larger lumens and thinner walls, thus indicating adaptation to water deficit. The top-performing Rytel provenance showed the highest phenotypical plasticity of lumen cross-section area and cell wall thickness of stemwood tracheids. The studied low-performing provenances, which originated from the Orr Mountains, had tracheids with thicker wall and smaller lumens, likely to ensure mechanical durability. The local provenance showed intermediate values of the studied wood anatomical proxies. The effect of provenance on wood anatomical proxies showed some variations among the trials, which differed by continentality, likely due to ecological transfer distance. The studied anatomical proxies were affected by weather conditions prior and during formation of a tree ring, yet these relationships differed by trial and provenance. In general, wood anatomy of earlywood was affected by temperature in the dormant period and beginning of summer, as well as precipitation in the end of the previous vegetation period. Proxies of latewood showed correlation with temperature (negative) and precipitation (positive) in summer, suggesting response to the availability of water. Considering the observed relationships, the top-performing provenances, particularly Rytel, have a high potential to sustain productivity of stands within the region in the future.
This study examines microhabitat abundance and composition on retention trees in 20 young stands in Latvia that were clear-cut between 2002 and 2004. Retention trees play a vital role in sustaining ...biological diversity after clear-cutting, but their mortality rate is often high due to post-harvest environmental changes. This study compares tree-related microhabitat (TreM) abundance and composition on retention trees of different dimensions, species, and vitality. The tree height and diameter were measured, and the living status and position of each tree were determined. The research questions of the study were to assess the relationships between TreMs, tree dimensions, and species, as well as to compare the occurrence of TreMs on living and dead wood. The comprehensive analysis revealed that larger tree diameters and specific tree species (Populus tremula, Fraxinus excelsior, and Salix caprea) lead to a higher abundance of TreMs. The results also highlighted the importance of preserving deadwood within forest stands as it enhances the observed abundance of TreMs. This study provides the missing information on TreMs in Latvia, thus providing data for comparison in a wider region.
The plasticity of climate-growth relationships of trees is one of the main factors determining the climate-induced changes in forest productivity and composition. In this study, high-frequency ...variation of tree-ring width (TRW) of four native and three alien tree species and two hybrids of Populus L. growing in Latvia (hemiboreal zone) was compared using a principal component analysis based on TRW indices for the period 1965–2009. The effect of climatic factors was assessed using a bootstrapped correlation analysis. Influence of common climatic factors related to the length of the vegetation season, winter temperature, and water regime in summer was traced in the TRW of the studied species and hybrids. The combination and effect of the identified factors differed by species (and hybrids), to a certain extent explaining the diversity of TRW patterns. Nevertheless, some similarities among the species were also observed, suggesting the plasticity of growth response. Scots pine was generally sensitive to winter temperatures, but Norway spruce was mainly sensitive to summer water regime, while black alder was sensitive to winter temperatures and precipitation in spring. In contrast, silver birch showed the lowest sensitivity to the tested climatic factors (demonstrating sensitivity to winter precipitation in a few sites), suggesting tolerance to weather fluctuations. The TRW of the alien species was primarily sensitive to climatic factors related to water regime in the summer of the year preceding the formation of tree-ring, implying differences in mechanisms regulating wood increment. Nevertheless, temperature in the dormant period was significant for European larch in a few sites, suggesting sensitivity to cold damage. The variation of TRW of Populus hybrids diverged from others, as their growth was negatively correlated with the temperature in autumn, spring, and summer and positively correlated with water balance. Although the annual water balance in Latvia is positive, the effect of water deficit on tree growth was apparent.
Productive Scots pine (
Pinus sylvestris
L.) stands in the Baltic region ensure high-quality sawlogs for the timber market and contribute to carbon sequestration. Spike knots are serious stem ...defects, which reduce the proportion of valuable timber; therefore, the extent of genetic control of their occurrence and relationship with other traits must be assessed for the potential to reduce negative impact via tree breeding. We aimed to evaluate the family effect on the presence of spike knots and its relation to growth traits in open-pollinated Scots pine progenies. A higher incidence of spike knots was associated with better height growth and the presence of lammas shoots. The family had a statistically significant effect on growth and spike knots, yet a mainly weak genotypic correlation was observed between both traits (
r
G
= − 0.25 … 0.40). The family mean heritability of the spike knots was moderate (
h
f
2
= 0.42 … 0.46), opposite to very low (
h
2
= 0.02… 0.05) single tree heritability. Although the presence of lammas shoots was low and was not affected by genetics, it showed a strong positive genotypic relationship with the formation of spike knots in the next growing season (
r
G
= 0.80). The potential to select fast growing families with a low probability of spike knots was indicated, but a more comprehensive analysis is necessary to determine the extent of the genetic relationship between this stem defect and lammas shoots.
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