by Audrey Verreault | 24 March 2023
Published in Frontiers in Plant Science 14: 1-24. https://doi.org/10.3389/fpls.2023.1137834
Introduction: Genomic selection is becoming a standard technique in plant breeding and is now being introduced into forest tree breeding. Despite promising results to predict the genetic merit of superior material based on their additive breeding values, many studies and operational programs still neglect non-additive effects and their potential for enhancing genetic gains.
Methods: Using two large comprehensive datasets totaling 4,066 trees from 146 full-sib families of white spruce (Picea glauca (Moench) Voss), we evaluated the effect of the inclusion of dominance on the precision of genetic parameter estimates and on the accuracy of conventional pedigree-based (ABLUP-AD) and genomic-based (GBLUP-AD) models.
Results: While wood quality traits were mostly additively inherited, considerable non-additive effects and lower heritabilities were detected for growth traits. For growth, GBLUP-AD better partitioned the additive and dominance effects into roughly equal variances, while ABLUP-AD strongly overestimated dominance. The predictive abilities of breeding and total genetic value estimates were similar between ABLUP-AD and GBLUP-AD when predicting individuals from the same families as those included in the training dataset. However, GBLUP-AD outperformed ABLUP-AD when predicting for new unphenotyped families that were not represented in the training dataset, with, on average, 22% and 53% higher predictive ability of breeding and genetic values, respectively. Resampling simulations showed that GBLUP-AD required smaller sample sizes than ABLUP-AD to produce precise estimates of genetic variances and accurate predictions of genetic values. Still, regardless of the method used, large training datasets were needed to estimate additive and non-additive genetic variances precisely.
Discussion: This study highlights the different quantitative genetic architectures between growth and wood traits. Furthermore, the usefulness of genomic additive-dominance models for predicting new families should allow practicing mating allocation to maximize the total genetic values for the propagation of elite material.
by Claire Morin | 22 March 2023
Bats play a significant ecological role as a natural insect control. Unfortunately, they have become increasingly rare since the appearance of a devastating fungal infection in 2010. Bat maternity colonies, which are sometimes located in people’s homes, are essential for the species’ survival.
Preserving the maternity colonies or resorting to methods that safely exclude bats by intervening at the right time of the year, is an invaluable gesture to protect bats.
This guide provides the recommendations to follow to intervene safely when it is necessary to remove bats from a building.
by Svetlana Savin | 15 March 2023
Published in Current Forestry Reports 9: 101-130. https://doi.org/10.1007/s40725-023-00181-6
Purpose of Review
Intensive forest management practices are being implemented worldwide to meet future global demand for wood and wood products while facilitating the protection of natural forest ecosystems. A potential decline in wood properties associated with rapid tree growth makes it essential to quantify the potential impact of intensive management on the process of wood formation and, in turn, on its suitability for various end-uses.
Recent Findings
Wood produced over short rotations is generally of lower quality because wood properties tend to improve with cambial age (i.e. the number of annual growth rings from the pith). The intensification of silvicultural practices can thus have measurable consequences for the forest products value chain. The use of new planting material from tree improvement programs could offset such effects, but questions arise as to the effects of a changing climate on wood produced from these plantations and the best silvicultural approaches to manage them.
Summary
Based on these recent findings, we provide reflections on the need for a modelling framework that uses the effects of cambial age, ring width and position along the stem to summarise the effects of tree growth scenarios on wood properties. We then present challenges related to our limited understanding of the effects of several drivers of wood properties, such as climate variation, genetic material, and forest disturbances, among others, and highlight the need for further data collection efforts to better anticipate the quality attributes of the future wood fibre resource. We conclude by providing examples of promising new tools and technologies that will help move wood quality research forward by allowing (1) fast, efficient characterisation of wood properties, and (2) up-scaling predictions at the landscape level to inform forest management decisions.
by Claire Morin | 15 March 2023
La rainette faux-grillon de l’Ouest (RFGO), Pseudacris triseriata, a obtenu le statut d’espèce vulnérable en 2001 selon la Loi sur les espèces menacées ou vulnérables du Québec (L.R.L.Q., E-12.01, r. 2). Le suivi des populations Since 2015, studies in the Montérégie region have focused on different characteristics of the western chorus frog’s habitat to determine the parameters to be used to facilitate its restoration and development. The purpose of this document is to make current knowledge and techniques available for the development of western chorus frog habitats. The optimal landscape occupied by the western chorus frog consists of 30% wetlands, mostly open areas, and up to 25% wooded areas. The hydrology of the temporary wetland habitats used by the western chorus frog for breeding has intrinsic variability correlated with the nature of the watershed and the amount of precipitation. A breeding habitat for larval development must reach a hydroperiod of 60 to 100 days and have direct sun exposure from 10:00 a.m. to 2:00 p.m. The choice of location and an assessment of hydrological characteristics are therefore essential. Knowledge of the receiving environment, its geomorphological characteristics and water quality is essential for successful developments.
by Audrey Verreault | 10 March 2023
Published in Forest Ecology and Management 535: 120897. https://doi.org/10.1016/j.foreco.2023.120897
Cumulative effects of nitrogen (N) deposition are a matter of concern in temperate forests of northeastern North America. Increased N deposition may stimulate forest growth and carbon sequestration while also causing N saturation, which may lead to soil cation depletion, particularly in base-poor systems. We applied ammonium nitrate for 13 years in a sugar maple (Acer saccharum; SM) stand at the rates of 3 (Low N, LN) and 10 times (High N, HN) the ambient N deposition rate. N concentrations in soil layers were similar among treatments, except for a nitrate increase in the top B horizon in the HN treatment. Exchangeable Ca2+, Mg2+, and K+ were significantly lower than for the Control, at least in one of the top organic soil layers in the HN treatment. The temporal dynamics of foliar chemistry revealed that N:P ratio increased and both Ca and Mn decreased in the early years following treatment initiation, but that they did not change much thereafter. Foliar Ca values in the HN treatment are the lowest reported in the literature. This probably explains why the proportion of crown dieback steadily increased over time, reaching values as high as 80% in the HN treatment in 2017.
