Tree Selection Research Articles

A simulation study comparing advanced marker-assisted selection with genomic selection in tree breeding programs.

Advances in DNA sequencing technologies allow the sequencing of whole genomes of thousands of individuals and provide several million single nucleotide polymorphisms (SNPs) per individual. These data combined with precise and high-throughput phenotyping enable genome-wide association studies (GWAS) and the identification of SNPs underlying traits with complex genetic architectures. The identified causal SNPs and estimated allelic effects could then be used for advanced marker-assisted selection (MAS) in breeding programs. But could such MAS compete with the broadly used genomic selection (GS)? This question is of particular interest for the lengthy tree breeding strategies. Here, with our new software "SNPscan breeder," we simulated a simple tree breeding program and compared the impact of different selection criteria on genetic gain and inbreeding. Further, we assessed different genetic architectures and different levels of kinship among individuals of the breeding population. Interestingly, apart from progeny testing, GS using gBLUP performed best under almost all simulated scenarios. MAS based on GWAS results outperformed GS only if the allelic effects were estimated in large populations (ca. 10,000 individuals) of unrelated individuals. Notably, GWAS using 3,000 extreme phenotypes performed as good as the use of 10,000 phenotypes. GS increased inbreeding and thus reduced genetic diversity more strongly compared to progeny testing and GWAS-based selection. We discuss the practical implications for tree breeding programs. In conclusion, our analyses further support the potential of GS for forest tree breeding and improvement, although MAS may gain relevance with decreasing sequencing costs in the future.

Density-dependent mortality models for mono- and multi-species uneven-aged stands: The role of species mixture

The self-thinning law describes the progressive mortality of growing trees in crowded even-aged stands because of competition. In uneven-aged stands, however, density-dependent mortality is relatively poorly known. We developed density-dependent self-thinning models for mono-species and multi-species uneven-aged stands. Three models for mono-species Picea abies, Abies alba and Fagus sylvatica stands, four models for mixed conifer/broadleaf stands and a model for single tree selection stands as a specific type of uneven-aged forest were parametrized by Quantile Regression (QR) and Stochastic Frontier Analysis (SFA) using data from n = 31,612 forest inventory plots in Slovenia. The average slope of the self-thinning line in uneven-aged stands of −1.422 was statistically significantly lower than Reineke’s slope. Maximum stand density was higher in mono-species stands than in multi-species stands. The higher the proportion of beech in a stand, the higher the intercept and slope of the maximum stand density line. In single tree selection stands, the intercept and the slope of the maximum stand density line were highest and statistically different from all other types of uneven-aged forests. Species mixture had an impact on the slope and intercept of the self-thinning line. The slopes of the self-thinning lines differed between the studied types by up to 36% and 69% in the SFA and QR models, respectively, while the intercepts differed by up to 13% and 24%, respectively. However, maximum stand densities differed significantly only between compositionally very dissimilar stand types, such as Fagus sylvatica- or Picea abies-dominated mixtures versus other broadleaf mixtures (e.g., Quercus petraea, Carpinus betulus). The SFA predictions of maximum stand densities were systematically lower and less varying than the QR predictions, but not statistically different. The models can be used to constrain individual tree growth models in uneven-aged forests and to estimate the onset of inter-tree competition in irregular stands.

Models of Purkinje cell dendritic tree selection during early cerebellar development.

We investigate the relationship between primary dendrite selection of Purkinje cells and migration of their presynaptic partner granule cells during early cerebellar development. During postnatal development, each Purkinje cell grows more than three dendritic trees, from which a primary tree is selected for development, whereas the others completely retract. Experimental studies suggest that this selection process is coordinated by physical and synaptic interactions with granule cells, which undergo a massive migration at the same time. However, technical limitations hinder continuous experimental observation of multiple cell populations. To explore possible mechanisms underlying this selection process, we constructed a computational model using a new computational framework, NeuroDevSim. The study presents the first computational model that simultaneously simulates Purkinje cell growth and the dynamics of granule cell migrations during the first two postnatal weeks, allowing exploration of the role of physical and synaptic interactions upon dendritic selection. The model suggests that interaction with parallel fibers is important to establish the distinct planar morphology of Purkinje cell dendrites. Specific rules to select which dendritic trees to keep or retract result in larger winner trees with more synaptic contacts than using random selection. A rule based on afferent synaptic activity was less effective than rules based on dendritic size or numbers of synapses.

Different triggers, different stories: Bark-beetle infestation patterns after storm and drought-induced outbreaks

In the recent decades, Norway spruce forests (Picea abiesKarst.) in Europe have been subject to large-scale tree mortality caused by the spruce bark beetle (Ips typographusL.). The outbreaks were induced by storm-felling events and periods of drought, which are becoming increasingly frequent due to climate change. Because storms and droughts spatially affect forests differently, the infestation patterns and configuration of the bark beetles might differ between storms and drought. In this study, we examined local and landscape factors associated with bark beetle-caused tree mortality after one storm (2005) and one drought-induced spruce bark beetle outbreak (2018), both occurring in southern Sweden. A total of 13,192 infested one-ha pixels after the storm and 6,425 one-ha pixels after the drought (in total 19,617) were compared regarding differences in infestation occurrence and size and associated forest structures and climate between the two different outbreaks, using a generalized linear model (GLM) approach. Based on our findings, we discovered that the allocation of infestation patch sizes (including four classes: 5–10, 11–25, 26–50 and >50 infested trees) for the two outbreaks were quite similar with a large proportion (>0.6) of small groups (≤10 trees).However, the outcomes from this study demonstrate that the drivers behind the spatial configuration of bark beetle infestations can differ considerably between outbreaks triggered by storms and droughts, and the main cause seems to be linked to the spatial distribution of susceptible trees. The most consistent differences for both occurrence and infestation size were that storm-induced infestations increased more with spruce volumes and area of protected forests (nature reserves) in the landscape; whereas for the drought-induced infestations, occurrence and size increased more with clear-cuts in the landscape and spruce heights across spatial scales. Soil moisture and mean drought index (SPEI; May-July) were important for both outbreaks, but generally more important for the infestation sizes after droughts than after storms and may involve a time-lagged effect.The reasoning behind the differences between storms and droughts may be that during storm-induced outbreaks, when the wind-felled trees are removed or not suitable anymore, bark beetles need to find specific susceptible standing trees, while after drought all trees are more or less stressed, which results in a selection of large trees in dry and warm landscapes as they have more resources and favorable reproduction conditions. Finally, we show that the previous infestation size influenced the later infestation size negatively within landscapes of 25 ha and this seems to be related to depletion of susceptible host trees.These results are important for the assessment of more specific outbreak predictions, which should be integrated in future risk mapping of bark beetle outbreaks.

From Conservation to Connection: Exploring the Role of Nativeness in Shaping People’s Relationships with Urban Trees

Deciding whether to plant native or non-native trees in public urban green spaces is becoming complex and conflicted, and decisions purely based on biotic nativeness are likely to be hamstrung as climate change and rising urban heat push many native species beyond their natural ranges. Importantly, tree selection considerations by urban planners and environmental managers will have to move beyond a primary focus on securing conservation and ecological outcomes, to elucidate and engage with a growing interest in the socio-cultural values and services of urban trees. Building on emerging theoretical perspectives, this place-based study explores the role that perceptions of nativeness have in shaping people’s relationships with native and non-native urban trees and landscapes in an Australian city. Nativeness was associated with a range of subjective meanings including cultural identity, political expression, nature connection, desirable and undesirable traits, and environmental and cultural compatibility. Our findings emphasise that the ways in which urban trees and green spaces are valued and experienced is likely mediated by people’s perceptions of nativeness and its importance relative to other attributes. To provision and sustain green spaces that meet the diverse needs and preferences of urban publics, planners and managers need to elucidate and incorporate the nuanced, place-based and multifaceted subjective meanings of nativeness into urban greening decision-making and practice.

Candidate Plus Tree Selection of Buchanania lanzan Tree in Central Region of Chhattisgarh

Candidate plus tree selection is considered as an important and preliminary step in tree improvement program of a particular species. Plus tree selection is the first step to improve production and quality in forestry. In present study, 85 candidates plus trees of chironji showing good phenotype have been selected from different places covering three districts of central Chhattisgarh region viz., Mahasamund, Gariyabandh and Kabirdham following comparison tree method.The tree height, DBH, clear bole height and average crown diameter varied from 6.5 m-16.5 m, 10.50 cm-40.42 cm, 1.2 m-4.0 m and 2.1m-6.8 m respectively. The highest tree height found for CPT 2 as 16.5 m in Komakhan village, Mahasamund district. The highest tree diameter at breast height (DBH) was found (CPT 2) 40.42 cm in BK Bahra village, Mahasamund district. The highest average crown diameter found was observed for CPT 14 and CPT 20 as 6.8 m in Neyur village Kabirdham district.

Effects of single tree selection cutting on vascular plant species diversity components in temperate forests of Hyrcanian region

Temperate forests in northern Iran are one of the most important natural ecosystems with the highest economic value and a key role in the conservation of forest biodiversity in Iran. We studied vascular plant species diversity components (alpha, beta and gamma) of herb and tree layers on 120 plots at six sites in forests managed by single tree selection and forests that have been left unmanaged for more than 30 years in the Hyrcanian forest zone in northern Iran. Generalized linear mixed models (GLMM) were used to analyse the effect of management on stand properties, tree and herb layer local diversity and soil characteristics. Despite the differences in herb layer local α-diversity, forest management did affect neither community composition of the herb layer nor regional γ-diversity. Also, species richness as well as α- and γ-diversity of the tree layer was significantly higher in managed forests, while β-diversity showed no directional response across herb and tree layers. According to constrained ordination analysis, main drivers for explaining variance in plant species composition were soil organic matter, total nitrogen, potassium, phosphorous, pH and forest structural variables (basal area, number of trees per hectare and canopy cover) in herb and tree layers. We found that in Hyrcanian forests single tree selection management promotes environmental conditions that effectively contribute to increased diversity of the herb and tree layers at the local and regional scale compared to unmanaged forests. The higher diversity of herb and tree layers is likely being driven by higher within-stand heterogeneity, improved light availability in managed forests due to lower stocking density and larger canopy gaps, or also results from topsoil disturbances through wood extraction. This study indicated that single tree selection system has the potential to be used in order to improve biodiversity conservation, and these results can be useful for development of management guidelines and decision-making processes.Because it may not be specific enough to dismiss or prioritize forest management regimes, based only on their impact on plant diversity, further assessments of forest management effects on other crucial factors (such as fauna diversity, structural diversity and forest ecosystems services) are needed.

Food tree selection by an arboreal marsupial: Implications for timber harvest

ContextThe Yellow-bellied Glider (Petaurus australis) is a vulnerable arboreal Australian marsupial that is threatened by logging. Trees used for sap feeding (sap trees) are a critical habitat requirement of the species, yet no harvest retention policy exists in the southern part of its range in Victoria, Australia. Yellow-bellied Gliders are extremely selective in sap tree use with some trees used far more frequently than others. AimsWe aimed to determine the tree species used and identify characteristics influencing intra-species tree selection for sap feeding by Yellow-bellied Gliders in the Highlands - Southern Fall Bioregion of Victoria. MethodsSap trees were located at each of 12 sites. We measured nine characteristics related to photosynthetic capability, microsite, and habitat for sap trees and the nearest tree of the same species without Yellow-bellied Glider incisions (reference tree). For sap trees, we measured 11 incision-related variables. Permutational Multivariate Analysis of Variance was conducted to identify distinguishing characteristics of sap trees. Generalised Linear Mixed Modelling was used to determine the influence of tree characteristics on abundance of incisions on a tree. Key resultsFive of 24 tree and tall shrub species present across the 12 sites were used for sap feeding. All five species were Eucalyptus. Within the tree species used, Yellow-bellied Gliders selected for trees that were larger, had wider crowns and occupied dominant and co-dominant canopy positions. ConclusionsYellow-bellied Gliders are highly selective of trees used for sap feeding. Although primarily selecting larger more dominant trees for sap feeding, lack of clear identifying characteristics means that identifying and retaining preferred sap trees in logging coupes must rely on site surveys for incisions on trees.

Modeling and predicting cancer clonal evolution with reinforcement learning.

Cancer results from an evolutionary process that typically yields multiple clones with varying sets of mutations within the same tumor. Accurately modeling this process is key to understanding and predicting cancer evolution. Here, we introduce clone to mutation (CloMu), a flexible and low-parameter tree generative model of cancer evolution. CloMu uses a two-layer neural network trained via reinforcement learning to determine the probability of new mutations based on the existing mutations on a clone. CloMu supports several prediction tasks, including the determination of evolutionary trajectories, tree selection, causality and interchangeability between mutations, and mutation fitness. Importantly, previous methods support only some of these tasks, and many suffer from overfitting on data sets with a large number of mutations. Using simulations, we show that CloMu either matches or outperforms current methods on a wide variety of prediction tasks. In particular, for simulated data with interchangeable mutations, current methods are unable to uncover causal relationships as effectively as CloMu. On breast cancer and leukemia cohorts, we show that CloMu determines similarities and causal relationships between mutations as well as the fitness of mutations. We validate CloMu's inferred mutation fitness values for the leukemia cohort by comparing them to clonal proportion data not used during training, showing high concordance. In summary, CloMu's low-parameter model facilitates a wide range of prediction tasks regarding cancer evolution on increasingly available cohort-level data sets.

New sources of biological data supporting environmental history of a tropical forest of south-eastern Brazil

The Tijuca Forest results from a reforestation project executed in the second half of the nineteenth century, with native and exotic species planted in the mountains of Rio de Janeiro, Brazil. Aiming at a theoretical reflection, the use of integrated methodologies from different areas of knowledge was evaluated to expand the research of the environmental history of a tropical forest in south-eastern Brazil, using everything from the search for historical documents to the counting of tree growth rings. It was possible to find some of the trees from the initial reforestation efforts, to circumscribe the locations of the first plantations, hitherto unknown, as well as the original intentions of tree selection: a reflection of the silvicultural model of the period that incorporated the tropical identity of the forest without giving up the market demand. The project area indicates that the planted forest would cover approximately 330 ha, prioritizing restoration by micro basins. In the 33 years analysed, about 155,000 trees were planted (110,000 with success) from a repertoire of at least 107 species, prioritizing the native ones. The quality of the wood, mainly for the naval segment, was prioritized, but other purposes were also met. The model and selection criteria for planting areas and species characterize a strategic plan that foresaw the recovery of water sources simultaneously with the generation of wealth in the medium and long term, diversifying the use of the soil and inaugurating a cycle of silvicultural exploitation in the country. This study re-signifies the understanding of the Tijuca Forest ecology, not only in space but mainly in time, revealing the subtle relationships between tropical nature and society in formation.

Three‐dimensional phenotyping of peach tree‐crown architecture utilizing terrestrial laser scanning

AbstractTree training systems for temperate fruit have been developed throughout history by pomologists to improve light interception, fruit yield, and fruit quality. These training systems direct crown and branch growth to specific configurations. Quantifying crown architecture could aid the selection of trees that require less pruning or that naturally excel in specific growing/training system conditions. Regarding peaches [Prunus persica (L.) Batsch], access tools such as branching indices have been developed to characterize tree‐crown architecture. However, the required branching data (BD) to develop these indices are difficult to collect. Traditionally, BD have been collected manually, but this process is tedious, time‐consuming, and prone to human error. These barriers can be circumnavigated by utilizing terrestrial laser scanning (TLS) to obtain a digital twin of the real tree. TLS generates three‐dimensional (3D) point clouds of the tree crown, wherein every point contains 3D coordinates (x, y, z). To facilitate the use of these tools for peach, we selected 16 young peach trees scanned in 2021 and 2022. These 16 trees were then modeled and quantified using the open‐source software TreeQSM. As a result, “in silico” branching and biometric data for the young peach trees were calculated to demonstrate the capabilities of TLS phenotyping of peach tree‐crown architecture. The comparison and analysis of field measurements (in situ) and in silico BD, biometric data, and quantitative structural model branch uncertainty data were utilized to determine the reconstructive model's reliability as a source substitute for field measurements. Mean average deviation when comparing young tree (YT) height was approx. 5.93%, with crown volume was approx. 13.26% across both 2021 and 2022. All point clouds of the YTs in 2022 showed residuals lower than 12 mm to cylinders fitted to all branches, and mean surface coverage greater than 40% for both the trunk and primary branching orders.

Evaluating criteria weights of street tree selection between residents and experts

Evaluating criteria weights of street tree selection between residents and experts

Изменчивость репродуктивного развития полусибов плюсовых деревьев Pinus sibirica Du Tour

Selection of Pinus sibirica Du Tour plus trees by seed productivity, breeding of half-sibs, characterized by an abundance of cones and pollen, serve as the basis for the creation of high-yielding target plantations. The aim of the research was to select families with a large percentage of early reproductive development's trees, and specimens with a lot of cones and shoots with male inflorescences. Also, to select specimens in different families of Pinus sibirica Du Tour plus trees by early reproductive development, taking into account the formation of cones and pollen. The subject of the study was the seed progeny of Pinus sibirica Du Tour trees at biological age of 31-35 years, grown on the territory of the arboretum of Reshetnev University, the site «Prodolzhenie geoshkoly» (N 55.9666666667, E 92.6166666667, 287 meters above sea level). Initially, five plus trees growing in Irkutsk (60/24) and Novosibirsk regions (98/62, 102/66, 106/70 and 110/74) for reproduction among certified plus trees by seed productivity were selected. The growing conditions and indicators of plus trees from the certificate drawn up by the commission during their certification are given. Cones from these trees were collected, then seeds were sown and planting material was grown, which was transplanted to the site of the arboretum of Reshetnev University. In 2018, 2021 and 2022, the number of cones and microstrobiles in early reproductive development semis by using binoculars was determined. The variability by early reproductive development of half-sibs in the formation of cones both between families of plus trees (7.8-25.3 psc.), and within families (60/24 – 2-22 psc.; 98/62 – 2-115 psc.; 102/66 – 4-45 psc.;106/70 – 1-54 psc.; 110/74 – 1-15 psc.) is noted. The selection of specimens by the size of the cones was not carried out. Some specimens formed both cones and pollen: 82-7, 85-10 and 87-13 in the family of the plus trees 60/24; 72-11, 79-2, 79-3, 79-4, 79-8, 80-3, 81-4, 85-22 (family 98/62); 83-1,83-6, 83-9, 84-2, 84-4, 86-9, 86-1 (family 102/66); 78-3, 78-9, 81-8, 81-9, 81-10, 85-19 (family 106/70); 79-9, 84-12, 86-5 (family 110/74). Selected specimens have a huge value and can be widely used in their vegetative reproduction and the creation of high-yielding plantations of early reproductive development.

Linear mixed model selection in forest tree breeding studies

Orman ağacı ıslah çalışmalarında, uzun süre gözlemlenen genetik testler ile ıslah programları için genetik parametreler tahmin edilmektedir. Söz konusu parametrelerin tahminleri ıslah programını etkileyeceğinden tahmin için kullanılacak doğrusal karma modelin seçimi büyük önem taşımaktadır. Kullanılan doğrusal karma modellerde tahmin, genellikle artık (residual) veya kısıtlı maksimum olabilirlik (REML) yöntemi kullanılarak elde edilir. Farklı sabit etkileri olan modellerin olabilirliğe (likelihood) dayalı bilgi kriterleri ile kıyaslanabilmesi için, modellerin maksimum olabilirlik (maximum likelihood) kullanılarak tahmin edilmesi önerilmektedir. Orman ağaçları ıslahı çalışmalarında doğrusal karma model seçiminde farklı modeller denenerek model uyumunu arttıran en kullanışlı model seçilmelidir. Orman ağaçları ıslah çalışmalarında modellerin uyumunu kıyaslamak için ise genellikle Akaike (AIC) bilgi kriterinin kullanılması önerilmektedir. Bu çalışmada, doğrusal karma model seçiminin gerekliliğini ve önemini ortaya koymak amaçlanmıştır. Bu amaç için, Muğla-Marmaris’te açık tozlaşma ürünü 168 aile (üvey kardeş) ile tesis edilmiş olan Kızılçam döl deneme sahasındaki ağaçların on ikinci yaş göğüs yüksekliği çap verileri kullanılarak modeller kıyaslanmıştır. Verilerin analizinde geleneksel (basit), mekânsal bileşen içeren, artığın bağımsız veya birinci dereceden iki boyutlu ayrılabilir otoregresif korelasyon hata yapısı olduğunu varsayan toplamda otuziki farklı model denenmiştir. Geleneksel modelin AIC değeri (Model-1=5594.1), mekânsal bileşen ve artığın otoregresif korelasyon yapısı içeren modellere kıyasla (Model-20=5447) daha yüksek bulunmuştur

Fine-grained water availability drives divergent trait selection in Amazonian trees

Water availability is an important driver of plant functional biogeography. Most studies focus on the effects of precipitation, and neglect the contribution of groundwater as a source when the water table depth (WTD) is accessible to roots. Previous studies suggested that shallow water tables select for acquisitive traits. These studies have mostly contrasted shallow vs. deep water tables, without considering a more fine-grained perspective within shallow water tables or the temporal WTD behavior. Here we tested whether the degree of variation in WTD translates into divergent modes of trait selection. We expect constantly shallow WTD leading to the selection of acquisitive traits, whilst high fluctuation of WTD would lead to tree communities with more conservative traits. We used community and trait data (wood density and leaf traits) from 25 1-ha forest monitoring plots spread over 600 km in central Amazonia, covering a gradient of shallow to intermediate (0–8 m deep) WTD along the Purus-Madeira interfluve. Wood density was measured directly in trunk cores (498 trees) and leaf traits (Specific Leaf Area, Leaf Dry Mass Content, Leaf Thickness) of >6,000 individuals were estimated with FT-NIR (Fourier-Transformed Near-Infrared Spectroscopy) spectral models calibrated with cross-Amazonian data. We observed a turnover of families, genera, and species along the gradient of temporal WTD fluctuation range. This taxonomic turnover was accompanied by a change in wood traits, with higher wood density associated to higher WTD fluctuation and higher climatic water deficit. Leaf traits, however, varied in the opposite direction than initially hypothesized, i.e., trees had more acquisitive traits toward intermediate WTD with higher fluctuation. Based on those results, we propose that the effect of WTD selection should be conceptualized in a quadratic form, going from water excess in very shallow WTD (<2 m, limiting condition due to anoxia, selecting conservative traits), to moist in intermediate WTD (between 2 and 5 m deep, favorable condition with constant water supply, selecting acquisitive traits), to water deficit in deep WTD (>5 m, limiting condition, with conservative traits again).

Investigating the effects of wind loading on three dimensional tree models using numerical simulation with implications for urban design

In this study, the effects of wind on an Eastern Red Cedar were investigated using numerical simulations. Two different tree models were proposed, each with varying bole lengths and canopy diameters. A total of 18 cases were examined, including different canopy diameters, bole lengths, and wind velocities. Using computational fluid dynamics (CFD) methods, the drag force, deformation, and stress of the tree models were calculated under different wind velocities and geometric parameters. A one-way fluid–structure interaction (FSI) method was used to solve the deformation of the tree. Additionally, velocity and pressure distribution around the tree were obtained. The results indicate that wind velocity and geometric parameters of the tree have a significant impact on deformation, drag force, and stress. As wind velocity increases from 15 to 25 m/s, the force on the tree increases substantially. The results also show that the diameter of the canopy has a bigger effect on stress and strain than the bole length. This study provides insights into tree behavior under wind loading for urban planning and design, informing optimal tree selection and placement for windbreak effectiveness and comfortable environments.

Concurrent Steiner Tree Selection for Global routing with EUVL Flare Reduction

The aggressive scaling down of the feature size in modern ICs has introduced major bottlenecks in printing layouts using a conventional 193nm immersion lithography system. As different mitigation techniques have reached their limitations, Next Generation Lithography (NGL) techniques have been gaining popularity. Extreme Ultra-violet Lithography (EUVL) system which uses light having 13.5nm wavelength is one of the popular NGL for printing features below 20nm. However, EUVL faces the problem of flare caused by irregular reflection from clear-field mask surfaces used. It leads to distortion of critical dimension (CD) during layout printing which in turn degrades the performance of the circuit. In this paper, we have formulated a delay-aware global routing problem in order to minimize flare without sacrificing the delay. Two different solvers, namely ILP and SAT-SMT, are employed and the results are compared. Experimental results show a significant reduction in flare without much compromise on delay.

An effective trap for spotted lanternfly egg masses.

Spotted lanternfly (SLF) (Lycorma delicatula (White)), an invasive planthopper discovered in Pennsylvania, USA in 2014, continues to spread and is now present in 14 states with substantial infestations present in seven states. Population projections using adult SLF trapping or visual counts are not reliable due to the transient, migratory behavior of the adults which make population forecasts difficult. Another approach to population monitoring is utilization of the stationary egg mass stage, but counting small cryptic egg masses throughout the canopy of large trees in dense woodlots is arduous and prone to error. After several field seasons testing various trapping configurations and materials, we have identified an efficient, simple, low-cost trap termed a 'lamp shade trap' that is attached to the lower trunk area of an SLF host tree. SLF females readily enter the trap and lay eggs on the thin, flexible trap surface. A vertical trap orientation was superior, and the most productive woodlots yielded an average of 47 and 54 egg masses per trap, and several traps had over 100 egg masses. There were 1,943 egg masses tallied from 105 traps placed at six locations in two states. Egg mass counts in the area above and below the traps and on nearby control trees yielded very few egg masses in comparison. Selection of trees 15 to 20 cm in diameter for trap placement is most efficient, yielding good egg mass abundance while minimizing the amount of trap material used. The lamp shade trap has potential as an effective tool to identify SLF in new areas, gauge SLF population levels in woodlots and can also be used to collect and monitor egg masses for research purposes.

Влияние аэротехногенных выбросов магнезитового производства на надземную фитомассу Betula pendula Roth в зависимости от плодородия почвы

The study of the test crop European birch elevated phytomass at the magnesite production impact zone (the Southern Urals, Satka) was carried out. Two plots of test crops of the same age (created in 1983) growing 3 km away from the source of technogenic pollution from magnesite production and with different soil fertility were studied. The elevated phytomass of the stand was calculated using sample trees. The selection of trees was carried out from different thickness levels within the entire range. A regression method was used to estimate the phytomass of the stand. In the course of our work, we tested the null hypothesis that soil fertility is a significant factor for the adaptation of the Betula pendula Roth to pollution since it was noted that stands on rich soils have the best growth (height, diameter) and the vital condition of the stand. A comparative analysis of the elevated phytomass of test crops with the same level of pollution by magnesite production emissions, but growing on soils of different fertility, allowed us to assess the effect of the soil factor on the ability of the European birch to adapt to technogenic pollution. Under the conditions of magnesite production emissions, the elevated phytomass of experimental Betula pendula Roth crops growing on highly fertile soils is not reduced to the same extent as that of birch growing on low-fertile soils. Under the negative emissions impact, the mass of wood and branches of the Betula pendula Roth growing on highly fertile soils decreases to a smaller extent than the mass of other fractions. The wood and branches weight of the Betula pendula Roth growing on highly fertile soils is 3.8 and 3.0 times higher, respectively, and the weight of leaves and bark is 2.3 and 2.4 respectively, compared with test plot No. 5 on low-fertile soils.

Identification agronomic character of local durian parent trees as a step to develop a durian center in Sukowono and Sumberjambe

Most of the durian plants in Indonesia come from old and grow wild trees, not from tree selection. The durian developed by farmers in Sukowono and Sumberjambe is a local durian trees. This is a factor causing the erosion of germplasm, so that the existence and sustainability of local durian plants is threatened. This fact certainly requires attention from all parties in preserving the parent tree of germplasm, especially by knowing the diversity of durian variants and planting in collection gardens. The parent tree is an individual tree that has the requirements as a seed-producing tree. Steps to determine the diversity of durian can be done by mapping and identifying the character of the durian parent tree. The mapping was carried out through a series of exploration, inventory and characterization activities for durian plants. This activity will help efforts to develop durian fruit that has commercial value while also preserving its genetic resources from extinction. Activities will be held from August to December 2022 in Sukowono and Sumberjambe, Jember Regency. The parameters observed in this activity were tree age, tree height, stem circumference, petiole length, leaf shape, leaf length, leaf width, leaf color, and plant productivity in fruiting each season.