Article
Agronomy
Anoj Subedi, Philippe Marchand, Yves Bergeron, Hubert Morin, Miguel Montoro Girona
Summary: Current ecological models predict that climate change will have significant effects on the natural disturbances of forests. The spruce budworm, a major defoliating insect in eastern North America, has a major impact on the Canadian boreal forest. Little is known about how climate fluctuations affect the growth of the spruce budworm host species during outbreaks.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Forestry
Cristian Corona, Abigail C. Leeper, Jalene M. LaMontagne
Summary: Eastern spruce budworm is a native defoliating insect in Canada and the United States, with different impacts on balsam fir and white spruce. A study of an outbreak in Wisconsin showed higher defoliation and mortality in white spruce, contrary to expectations.
FOREST ECOLOGY AND MANAGEMENT
(2022)
Article
Plant Sciences
Adam D. Polinko, Marguerite A. Rapp, Andrew J. Sanchez Meador, Andrew D. Graves, Daniel E. Ryerson, Kristen M. Waring
Summary: The western spruce budworm is a highly destructive defoliator of forests in the western US. Forests in northern New Mexico have experienced severe defoliation and mortality caused by western spruce budworm outbreaks. The impacts of these outbreaks on forest dynamics in the US Southwest are still not well understood. This study found unsustainable levels of mortality in spruce-fir stands and a shift towards non-host species in mixed-conifer stands. It also suggests that mixed-conifer stands affected by these outbreaks may have increased resilience to future budworm defoliation events.
Article
Ecology
Amberly R. Tai, Allan L. Carroll
Summary: Outbreaks of western spruce budworm have shifted northward in Douglas-fir forests of western Canada, possibly due to climate change-induced alterations in synchrony between larval emergence and bud development.
FRONTIERS IN FORESTS AND GLOBAL CHANGE
(2022)
Article
Forestry
Djidjoho Julien Houndode, Cornelia Krause, Hubert Morin
Summary: During spruce budworm outbreaks, balsam fir stands experience marked levels of mortality due to consecutive years of defoliation. Factors such as defoliation duration and intensity, stand age, and forest composition play significant roles in predicting balsam fir mortality rates. Models have shown that cumulative defoliation, stand age, and the proportion of other tree species in the stand are essential for accurately predicting mortality rates in balsam fir stands affected by spruce budworm outbreaks.
FOREST ECOLOGY AND MANAGEMENT
(2021)
Article
Forestry
Cen Chen, Parinaz Rahimzadeh-Bajgiran, Aaron Weiskittel
Summary: Simulated research shows that spruce budworm defoliation generally becomes widespread within 3 years of its initiation, in agreement with historical observations. Current-year defoliation has almost no correlation with defoliation more than a year ago, possibly due to the dispersal of spruce budworm sustaining defoliation across space and time.
ANNALS OF FOREST SCIENCE
(2021)
Article
Ecology
Hiromitsu Sato, Emeline Chaste, Martin P. Girardin, Jed O. Kaplan, Christelle Hely, Jean-Noel Candau, Stephen J. Mayor
Summary: The Eastern Spruce Budworm (ESBW) is a major disruptor in Canada's boreal forests, causing widespread defoliation and high mortality rates of fir and spruce trees. This can result in economic losses and increased fire potential. Our study presents a novel representation of host-specific defoliation in a Dynamic Global Vegetation Model (DGVM), which successfully simulates the spatiotemporal patterns of ESBW based on historical observations. We also analyzed the interaction between ESBW and wildfire, finding that wildfire is slightly enhanced after ESBW outbreaks due to increased fuel loads, particularly in drier regions.
ECOLOGICAL MODELLING
(2023)
Article
Forestry
Alvaro Fuentealba, Emile Pelletier-Beaulieu, Alain Dupont, Christian Hebert, Richard Berthiaume, Eric Bauce
Summary: This study evaluates the efficacy of three Btk application treatments for protecting white spruce and balsam fir in mixed stands. The results show that Btk treatments are effective in reducing defoliation on balsam fir, but not on white spruce. The low efficacy on white spruce may be due to its shoot phenology and foliar chemistry.
Article
Ecology
Vincent Nealis, Jacques Regniere
Summary: A study on outbreak populations of western spruce budworm in Douglas-fir forests in British Columbia found that factors influencing population density changes included generation survival, larval survival, and dispersal of moths. Of particular importance were the survival rates of small, non-feeding larval stages, feeding larvae, and pupal stages. The differential in adult densities among locations in outbreak areas resulted in greater per-capita egg recruitment to areas of lower density, leading to apparent synchrony and extended duration of outbreaks.
Article
Environmental Sciences
Shawn D. Donovan, David A. MacLean, Yun Zhang, Michael B. Lavigne, John A. Kershaw
Summary: This study introduced a new method for estimating annual spruce budworm defoliation using change detection of vegetation indices derived from satellite hyperspectral imagery. The accuracy of classifying defoliation using this method was significantly higher than that of aerial surveys.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Forestry
Zelin Liu, Changhui Peng, David A. MacLean, Louis De Grandpre, Jean-Noel Candau, Daniel Kneeshaw
Summary: The impact of early intervention strategy (EIS) and foliage protection strategy (FP) on forest carbon (C) dynamics during spruce budworm outbreaks is still unclear. This study found that applying FP in the areas with the greatest potential C losses resulted in a greater reduction in cumulative net ecosystem productivity (NEP) than a higher proportion of FP. Successful implementation of EIS for 12 years can maintain more forest C than FP applied everywhere. The effectiveness of treatments during spruce budworm outbreaks depends on forest species, age, and their interactions.
Article
Forestry
Jacques Regniere, Chris J. Sanders
Summary: We measured the foliage area, weight, and number of buds on balsam fir and white spruce trees, and observed that spruce budworm larvae preferentially attack buds that grow in clusters on balsam fir trees. Equations were developed to predict the foliage area, weight, and bud numbers for estimation of absolute population density of spruce budworm.
Article
Ecology
Dominik Florian Stangler, Tobias Walter Miller, Harald Honer, Elena Larysch, Heike Puhlmann, Thomas Seifert, Hans-Peter Kahle
Summary: This study examines the response of Norway spruce, silver fir, and Douglas fir to drought events. It finds that Norway spruce is declining under climate change, silver fir is more vulnerable to drought than expected, and Douglas fir has superior growth rates and drought tolerance.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2022)
Article
Biochemistry & Molecular Biology
Pauline Gerardin, David Hentges, Philippe Gerardin, Pierre Vinchelin, Stephane Dumarcay, Coralie Audoin, Christine Gerardin-Charbonnier
Summary: The extractive contents of three softwood species commonly used in the wood industry, namely Silver fir, spruce, and Douglas fir, were quantitatively determined. It was found that branchwood samples located close to the stem had high extractive contents similar to those of knots. HPLC analysis showed similar chemical compositions, suggesting that the first cm of branches could be considered as an additional source of knotwood. The study also investigated the antibacterial, antifungal, and antioxidant activities of knotwood extractives.
Article
Forestry
Antonio Gazol, Cristina Valeriano, Alejandro Cantero, Marta Vergarechea, Jesus Julio Camarero
Summary: Debate exists regarding which tree species can sustain forest ecosystem services in a drier and warmer future. The use of non-native timber species, like Douglas fir, is suggested as a solution to mitigate climate change impacts in Europe. However, more research is needed to define the biogeographical, climatic, and ecological limits for widely planted timber species. This study found that the growth of Douglas fir is constrained by warm and dry conditions, particularly in dry areas.
Article
Forestry
Roberts Matisons, Didzis Elferts, Oskars Krisans, Volker Schneck, Holger Gartner, Alexander Bast, Tomasz Wojda, Jan Kowalczyk, Aris Jansons
Summary: The study evaluated the responses of Scots pine in the eastern Baltic region to meteorological conditions, showing explicit regional gradients in radial growth responses based on local climates. Temperature and water deficit were identified as the main drivers of tree-ring width, with non-linear effects indicating spatiotemporal gradients in growth responses. The findings suggest limitations in the adaptability of Scots pine populations in the longer term, emphasizing the need for climate-smart management for forest sustainability in the future.
FOREST ECOLOGY AND MANAGEMENT
(2021)
Article
Geosciences, Multidisciplinary
Markus Egli, Guido Wiesenberg, Jens Leifeld, Holger Gartner, Jan Seibert, Claudia Roosli, Vladimir Wingate, Wasja Dollenmeier, Pascal Griffel, Jeannine Suremann, Jan Weber, Mergime Zyberaj, Alessandra Musso
Summary: The study explores the dynamics of the landscape in the Three Lakes Region of Western Switzerland, with a particular focus on the formation and degradation of mires. Over the past 2000 years, hydrodynamic and geomorphic activities have increased, leading to severe degradation of moorlands, with mean annual carbon losses of 4.9 t ha(-1) in agricultural land and 2.4 t ha(-1) in forests. Forests can limit but not completely stop the degradation of mires, suggesting that agroforestry may be a potential alternative land-use system for sensitive areas in the future.
SWISS JOURNAL OF GEOSCIENCES
(2021)
Article
Forestry
Giulia A. V. Fontana, Markus Egli, Holger Gaertner
Summary: Dendrochronology has been used globally to reconstruct historical geomorphological events and climatic conditions. This study specifically focuses on the potential of mountain avens to provide accurately dated information about past debris-flow events. While the development of a mean chronology for the study area was unsuccessful, the cross-dated ages of individual shrubs allowed for the reconstruction of debris-flow events.
Article
Forestry
Roberts Matisons, Stefanija Dubra, Iluta Dauskane, Karlis Bickovskis, Aris Jansons, Holger Gartner
Summary: The study highlights the importance of non-structural carbohydrates reserves in trees for coping with weather extremes and ensuring survival and ecological plasticity. It reveals that the quantity and size of wood rays storing NSC in Scots pine stemwood vary among trees, with differences between dominant and intermediate trees. Additionally, variations in WR characteristics between earlywood and latewood show interannual changes, influenced by meteorological conditions and climate factors.
Article
Plant Sciences
Emad A. Farahat, Holger Gartner
Summary: The study analyzed about 300 perennial desert plants in Egypt, identifying 94 species that form growth rings. The distinctness of growth rings in these species is mainly indicated by ring porosity, fiber layer, and parenchyma. Further research on the annual rhythm of xylem formation is needed to confirm the annual nature of growth rings in these desert plants.
Article
Forestry
Roberts Matisons, Didzis Elferts, Oskars Krisans, Volker Schneck, Holger Gartner, Tomasz Wojda, Jan Kowalczyk, Aris Jansons
Summary: The abundance of Norway spruce in the Eastern Baltic region is predicted to decrease due to climate change, with uncertainties regarding growth potential due to the plasticity of local populations. Weather-growth relationships for the tree species are mainly influenced by summer moisture regime, with both linear and non-linear growth responses observed across the climatic gradient from Southern Finland to Northern Germany. Linear weather-growth relationships were found to be spatially and temporally non-stationary, with exceptions in Poland and Northern Germany.
Article
Environmental Sciences
Jussi Griessinger, Wolfgang Jens-Henrik Meier, Alexander Bast, Annette Debel, Isabelle Gaertner-Roer, Holger Gaertner
Summary: The presence of permafrost can distort the climate-proxy relationship of trees, while trees growing outside of the permafrost distribution provide a stronger and more consistent climate-proxy relationship over time.
Article
Plant Sciences
Petia Simeonova Nikolova, Jan Geyer, Peter Brang, Paolo Cherubini, Stephan Zimmermann, Holger Gartner
Summary: Silvicultural interventions like strip cuttings can alter resource availability for trees at forest edges, potentially changing root-shoot allometry. This study found that strip cutting led to increased root growth and optimized resource uptake, with strongest effects seen in regularly managed stands with tall trees. However, the changes in root-stem allometry post-cutting were short-lived, with the most significant effects seen in smaller, previously suppressed trees. Further analysis of stable isotopes is recommended for a more mechanistic understanding of environmental drivers.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Biophysics
Emad Farahat, Paolo Cherubini, Matthias Saurer, Holger Gaertner
Summary: The study found that Moringa peregrina trees in the Egyptian desert have shown characteristics such as decreased tree-ring widths, increased VLA% in dry years, and changes in δC-13 and δO-18 isotope values over the past decade. The intrinsic water-use efficiency of the trees has gradually declined, while the intercellular carbon concentration and Ci/Ca ratio have increased.
INTERNATIONAL JOURNAL OF BIOMETEOROLOGY
(2022)
Article
Forestry
Pawel Matulewski, Agata Buchwal, Holger Gartner, Andrzej M. Jagodzinski, Katarina Cufar
Summary: This study provides important insights into wood anatomy and radial growth in tree roots, particularly regarding the effects of ecological factors and trampling on root growth. The study also identifies blue rings in tree roots for the first time. The findings highlight significant growth discrepancies within a single root system and present a new challenge for future dendroecological studies.
Article
Forestry
Loic Schneider, Holger Gaertner
Summary: Fused Deposition Modeling (FDM), also known as 3D printing, has revolutionized modern manufacturing processes due to its ability to print a wide range of materials. The use of FDM in prototype development allows for rapid iteration from idea to product, with the timeframe ranging from a few hours to a few days depending on complexity. This paper showcases the use of an open-source 3D software and a 3D printer in producing parts for devices used in wood anatomy and dendroecology, providing detailed examples and highlighting the basic requirements for prototyping.
Editorial Material
Forestry
Johannes Edvardsson, Hans W. Linderholm, Bjorn Gunnarson, Anton Hansson, Tzu Tung Chen, Holger Gartner
Article
Multidisciplinary Sciences
Holger Gartner, Loic Schneider, Sandro Lucchinetti, Paolo Cherubini
Summary: In dendroecological research, it is crucial to accurately date each single growth ring for various studies. The way samples are taken is essential for successful preparation and analysis.
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2023)
Article
Plant Sciences
Emad A. Farahat, Holger Gartner
Summary: This study aims to evaluate the anatomical structure and dendrochronological potential of three Mediterranean desert shrubs in Egypt using X-ray density. The results showed distinct growth rings at macroscopic and microscopic levels, and the vessel traits reflected each species' adaptability to arid climate conditions. More efficient dendrochronological studies on subtropical and Mediterranean trees are recommended, including xylogenesis studies, collection of phenological data, sampling a sufficient number of trees per species, using new techniques, and choosing homogeneous and close sites for wood sampling.
FRONTIERS IN PLANT SCIENCE
(2023)