The New Zealand Journal of Forestry Science is an international journal covering the breadth of forestry science. Planted forests are a particular focus but manuscripts on a wide range of forestry topics will also be considered. The journal's scope covers forestry species, which are those capable of reaching at least five metres in height at maturity in the place they are located, but not grown or managed primarily for fruit or nut production or consumption. Original articles must report on a completed piece of substantial research that is relevant to an international audience. In all cases, a hypothesis must be presented and results must be sound without errors of fact, logic, interpretation, or calculation. Key details must be provided for all methods used. The correct statistical tests must be applied, where appropriate. Discussion must be logical and comprehensive, yet concise. Any conclusions must be justified and supported by the data presented. Short notes and subject reviews will also be considered if they are within the scope of the journal. Conference papers may be acceptable if they are part of a set of proceedings being published by the journal. The journal's policies and processes relating to Conflicts of interest, Peer review, Misconduct and Complaints are available here All articles published by New Zealand Journal of Forestry Science are made freely and permanently accessible online immediately upon publication. There are no Article Processing Charges (APCs) or submission charges. Papers published in the New Zealand Journal of Forestry Science are archived by the Bioeconomy Science Institute|Scion Group and also by the National Library of New Zealand under its Legal Deposit scheme.
Authors of articles published in New Zealand Journal of Forestry Science retain the copyright of their articles and are free to reproduce and disseminate their work. Authors may also grant any third party the right to use the article freely as long as its integrity is maintained and its original authors, citation details and publisher are identified. Open access All articles published by New Zealand Journal of Forestry Science are made freely and permanently accessible online immediately upon publication, without subscription charges or registration barriers. This work is licensed under a Creative Commons Attribution 4.0 International License.
Oil heat-treatment of Eucalyptus nitens (H.Deane & Maiden) Maiden timber
Background: Thermal modification of nondurable Eucalyptus nitens timber was reported to result in excessive checking and only marginally improved durability when heat treating in steam or atmospheric environments. This study investigated if oil heat-treatment of E. nitens above 210°C was able to overcome previously reported difficulties. Methods: Eucalyptus nitens clears were oil heat-treated to 210°C, 220°C and 230°C and assessed for density, stiffness, strength, colour and decay resistance. Results: Oil heat-treated E. nitens samples showed mass loss matching the highest durability class when tested against the brown-rot Rhodonia placenta (Fr.) Niemelä, K.H.Larss. & Schigel and the white-rot Trametes versicolor (L.) Lloyd, matching Durability Class-2 rated Eucalyptus muelleriana A.W.Howitt heartwood. Oil heat-treated E. nitens samples outperformed Pinus radiata treated with chromated copper arsenate (CCA) to Hazard Class (H3) grade when tested for the brown-rot R. placenta. While oil heat-treatment reduced mean stiffness (MoE) and strength (MoR), the resulting material exceeded characteristic SG8 grade values. No checking was observed in the oil heat-treated E. nitens boards. Letting samples cool outside the oil bath limited uptake of oil to less than 4 mm in depth. The planed product became darker the higher the oil heat-treatment temperature. Conclusions: Oil heat-treatment above 210°C has the potential to refine E. nitens timber, avoiding excessive degrade and providing decay resistance.
Copyright (c) 2025 Clemens Michael Altaner, Frederick Amin Anthonio, John Robert Fairweather (Author) http://creativecommons.org/licenses/by/4.0
Long term monitoring of red needle cast. What drives episodic outbreaks on radiata pine in New Zealand?
Background: Red needle cast (RNC) is a foliar disease of radiata pine (Pinus radiata D.Don) in New Zealand caused by Phytophthora pluvialis Reeser, W.L.Sutton & E.M.Hansen and, to a lesser extent, Phytophthora kernoviae Brasier, Beales & S.A.Kirk. Incidence and severity of RNC vary substantially between years. To investigate the impact of seasonal weather variables on this variation, RNC was assessed annually for ten years at radiata pine transects. Methods: Fifty-three transects were established in 2015 in the Central North Island and Gisborne Region (east coast North Island) of New Zealand, with twenty-three monitored until 2024 (surviving harvest). The relationship between seasonal weather variables and RNC severity was analysed using two non-parametric statistical approaches: (1) correlation analyses (Spearman correlations, rs, where positive values indicate an increase in RNC severity with an increase in the explanatory variable); and (2) binary recursive partitioning (with models trained on 85% of observations and tested on the remaining 15%). Results: Disease expressed more consistently, and severity was generally greater, at Gisborne sites. Disease severity peaked in 2017 and 2023 in both regions. Autumn (March-May) variables tended to be prevalent amongst predictors of RNC severity. Autumn soil moisture index (calculated from cumulative rainfall and evapotranspiration) was the most strongly correlated variable for the Gisborne dataset (rs = 0.70) and, along with vapour pressure, were the key partitioning variables in the recursive partitioning model. The strongest correlating variable for the Central North Island dataset was autumn potential evapotranspiration (rs = -0.46) while the most important variable and first data partition was autumn vapour pressure. Model evaluation metrics indicated good performance: R2 values were 0.63 and 0.68 for the Gisborne and Central North Island test datasets respectively, and mean absolute errors were 18.1 % and 7.8 % for the respective datasets. Conclusions: The importance of autumn more than summer weather variables in determining disease expression differs from the findings of previous studies and indicates that conditions during periods of exponential epidemic growth may be as, or more, important than initial inoculum level in determining RNC severity. Proactive control activities may require long-term weather forecasting or frequent monitoring during this season.
Copyright (c) 2025 Stuart Fraser, Emily McLay, Christine Todoroki, Nicolò Camarretta, Ian Hood (Author) http://creativecommons.org/licenses/by/4.0
Performance of global canopy height models across varied New Zealand vegetation types
Background: Global canopy height models are becoming prolific yet require evaluation across New Zealand's diverse vegetation types to assess their accuracy and applicability. Accurate measurement of canopy height is crucial for estimating above-ground woody biomass, which is essential for modelling carbon emissions and sequestration in the context of climate change. These models generally rely on remote sensing data and machine learning techniques, with Light Detection and Ranging (LiDAR) technology commonly employed for precise measurement. Methods: This study validated the three latest global canopy height models, each provided at a different resolution: 30-metre, 10-metre, and 1-metre. We assessed the accuracy of the selected models by comparing them against canopy height estimates derived from local Airborne Laser Scanning (ALS) datasets, which served as our reference data. Eleven regions across New Zealand were selected based on ALS data availability, encompassing five vegetation and land cover types. Our methodology involved utilising and automating the processing of large New Zealand ALS datasets. To align resolutions for comparison, the reference canopy height was calculated by aggregating average or maximum heights at 10 and 30 m spatial resolution. Model performances were assessed using statistical metrics, including root-mean-square error (RMSE), bias, and R². Results: Overall, all models exhibited relatively low R² values, indicating limited capture of canopy height variability. The Potapov 30-metre model performed best with average aggregation in shorter vegetation. In contrast, the Lang 10-metre model showed improved accuracy with maximum aggregation, particularly in taller vegetation, but visual boundaries between different vegetation types were not as distinct. The Tolan 1-metre model provided a balanced approach, minimising biases in lower heights but underestimating taller canopies. Results highlight model-specific strengths for varying vegetation structures and the sensitivity of performances to aggregation methods applied to high-resolution reference ALS data. Conclusions: All three global canopy height models exhibit varied performance across New Zealand's vegetation types. The findings highlight the importance of vegetation-specific applications to optimise each global model’s accuracy. Currently, these models are suitable for carbon accounting efforts as supplementary tools rather than replacements for existing methodologies.
Copyright (c) 2025 Sue Kee Ng, Pascal Sirguey, Todd Redpath (Author) http://creativecommons.org/licenses/by/4.0
Quantifying radial growth loss from red needle cast in Pinus radiata D.Don plantations
Background: Red needle cast (RNC), caused by Phytophthora pluvialis Reeser, W.L. Sutton & E.M. Hansen, is a significant foliar disease impacting Pinus radiata D.Don in New Zealand. First detected in 2005, the disease has now been observed in all regions of the country. In the most severe cases, defoliation of entire tree crowns can occur at a landscape scale. While some evidence of growth loss and productivity reduction has been reported, quantitative estimates of the effect of RNC on productivity are needed to inform disease management and mitigation decisions. This study aims to assess both short- and long-term losses in radial growth due to RNC. Methods: We used tree cores to quantify yearly basal area increments at two plantations: a 32-year-old stand in Wharerata Forest, with documented history of outbreaks both severe and cyclic in nature, and a 26-year-old stand in Kinleith Forest, where 8 years of continuous disease severity monitoring has been conducted at the tree level. A Bayesian multilevel modelling framework was used to predict growth losses due to RNC at both sites, accounting for yearly weather and outbreak severity. Results: We predicted a 31% to 51.5% radial growth loss in the year following an RNC outbreak, with reduced growth detectable for 3 to 4 years after disease, amounting to up to 30.6% growth loss over the course of a single event. Recurring disease events every three to four years can lead to a 20% reduction in total radial area growth over the period encompassing the presence of the disease, with no evidence that each additional RNC event aggravates growth loss. Conclusions:
Copyright (c) 2025 Joane S. Elleouet, David W. Lane, Lindsay S. Bulman, Yvette L. Dickinson, Stuart Fraser (Author) http://creativecommons.org/licenses/by/4.0
Use of geospatial technologies in New Zealand’s plantationforestry sector – a decade of change
Background: Geospatial technologies have emerged as powerful tools for optimising forest management, improving operational precision, and supporting data-driven decision-making. This study aims to understand the technologies adopted by the New Zealand plantation forest industry and identify any barriers to the uptake of geospatial tools. This is the third such study, following comparable surveys in 2013 and 2018. Methods: An online survey was sent to 29 organisations in New Zealand’s forestry sector. Topics included organisation demographics, data acquisition, positioning technology, remote sensing technologies, software, and Artificial Intelligence (AI). Specifically, the survey focused on five remote sensing technologies: aerial photography, aerial videography, multispectral imagery, hyperspectral imagery, and LiDAR. Each section contained questions relating to the acquisition and application of the remote sensing technology and the software used for data processing. Questions were included to ascertain barriers to adoption. To identify changes in technology usage and uptake, results were compared to the 2013 and 2018 studies. Results: Twenty-seven of the 29 queried organisations responded, resulting in a 93% response rate. Responding organisations managed 1,283,000 hectares (74% of New Zealand’s plantation forest estate), with estate sizes ranging from about 7,000 to 200,000 hectares. Data acquisition from online portals included aerial imagery (100%), property ownership data (96%), and elevation data (89%), primarily from the Land Information New Zealand (LINZ) Data Service. Global Navigation Satellite Systems (GNSS) technology was universally employed. All respondents acquired aerial photography. In addition, 67% acquired multispectral imagery, 4% acquired hyperspectral imagery, and 93% acquired LiDAR data. The AI topic was surveyed for the first time and the technology was used by 30% of respondents when working with geospatial data. The main barrier to using remotely sensed data was the lack of perceived benefits, while the primary barrier to AI adoption was a lack of staff knowledge and training. Except for hyperspectral imagery, all remote sensing technologies saw increased uptake since 2013. LiDAR experienced the largest growth, with uptake increasing from 17% in 2013 to 93% in 2023. ArcGIS remains the primary tool for geospatial analysis, used by 96% of respondents. Notably, the use of open-source software such as QGIS increased by 31% over the past decade. Conclusions: This study demonstrated an overall increase in the usage of geospatial technology in the forestry sector. To promote further uptake, it is important not only to increase exposure to available tools and provide training, particularly on emerging technologies such as AI, but also to demonstrate the practical and economic value these technologies can offer.
Copyright (c) 2025 Cong Xu, Anna Manning , Ning Ye, Justin Morgenroth (Author) http://creativecommons.org/licenses/by/4.0
Development of a height-diameter model for New Zealand grown tōtara (Podocarpus totara G. Benn. ex D. Don)
Background: Robust species-specific height-diameter (H-D) equations are necessary for the estimation and prediction of tree volume, yield, biomass or carbon stocks. In addition, information about height growth characteristics allows for the analysis of stand growth dynamics. But there is a general lack of species-specific growth models for most New Zealand native tree species considered for plantation and wood production. Therefore, the aim of this study was to develop a species- and site-specific H-D model for planted lowland tōtara (Podocarpus totara G. Benn. ex D. Don). Methods: The models were developed using data from 719 individually measured trees aged 11 to 110 years from eight different sites in the North Island of New Zealand. Two different modelling approaches, traditional non-linear and linear mixed effect, were used. The process included selecting, testing, conditioning, and extending a total of 18 different equations by incorporating site-specific tree variables. Results: The most precise model predicting the H-D relationship was reported by linear mixed-effect models that include diameter at breast height (DBH at 1.4 m, cm) and age (years). The final model had a low root mean square error (RMSE, 0.21, m), mean absolute error (MAE, 0.16, m) and high R2 (0.94), which slightly increased during validation. Conclusions: The study demonstrated a robust process and reported the most plausible and parsimonious model to predict P. totara’s H-D relationship, which serves as the basis for species-specific growth dynamics. The reported models provide for the first time the opportunity to predict the H-D relationship of planted P. totara in New Zealand. This fills a long existing knowledge gap and provides forest growers and managers important decision-making information.
Copyright (c) 2025 Serajis Salekin, Christian Roschak, Greg Steward (Author) http://creativecommons.org/licenses/by/4.0
Enhancing growth and quality of Handroanthus impetiginosus (Mart. ex DC.) Mattos (Bignoniaceae) seedlings by rhizobacteria inoculation
Background: Handroanthus impetiginosus (lavender trumpet tree) is valued for its construction, medicinal, and ecological uses. However, its slow initial growth and weak root system hinder seedling production. Rhizobacteria from the genera Bacillus and Azospirillum enhance plant growth and resilience. This study evaluated their effects on H. impetiginosus seedling development. Methods: The experiment was conducted in a greenhouse at the Experimental Nursery of Ornamental and Forestry Plants - College of Agricultural and Veterinary Sciences (UNESP/FCAV), Jaboticabal, Brazil, during the summer 2022/23. A completely randomised design included five treatments: Bacillus subtilis, B. megaterium, B. amyloliquefaciens, Azospirillum brasilense, and a control (no inoculation). Each treatment had four replicates of 20 plants. Seeds were sown in 280 cm³ tubes with a commercial substrate, composed of peat, vermiculite, roasted rice husk, calcined dolomitic limestone, NPK 14-16-18, and micronutrients. The rhizobacteria were inoculated at 30 and 60 days after sowing. Growth parameters (shoot height, stem diameter, root length, and biomass) were assessed at 107 days. Photosynthetic performance and microbiological colonisation were also evaluated. Data were analysed using ANOVA, Tukey’s test and Pearson correlation. Results: Azospirillum brasilense significantly enhanced growth, with the highest averages for shoot height (13.9 cm), stem diameter (1.72 mm), shoot dry mass (0.172 g), and total dry mass (0.686 g). It also improved seedling quality indices, including the Dickson Quality Index and shoot height-to-stem diameter ratio. Photosynthetic efficiency increased when inoculated with Azospirillum brasilense, as indicated by greater leaf area and chlorophyll content. Colony Forming Units (CFU) analysis showed higher bacterial colonisation in the substrate, roots, and aerial parts of A. brasilense-treated plants, with strong correlations between colonisation and plant growth. Conclusions: Azospirillum brasilense was the most effective rhizobacterium promoting H. impetiginosus seedling growth and quality. Its use could enhance reforestation and nursery production efficiency, accelerating seedling establishment. These findings highlight the potential of rhizobacteria to improve seedling vigour and adaptation in early growth stages.
Copyright (c) 2025 Thiago Souza Campos, Antonio Maricélio Borges de Souza, Guilherme Rodrigues Vieira (Author); André Caturelli Braga; Carlos Henrique Barbosa Santos, Everlon Cid Rigobelo, Kathia Fernandes Lopes Pivetta (Author) http://creativecommons.org/licenses/by/4.0
Are uncrewed aerial spraying systems the future for forestry pesticide application?
Background: Pesticide application is a primary method for managing weeds, insect pests and pathogens in New Zealand’s forests. Apart from some manual spot spraying, most pesticide applications are made using helicopters, with herbicides the most widely used pesticide class. Current aerial application practices have evolved into efficient operations designed to provide a balance between performance criteria, i.e. maximising treatment efficacy, minimising unwanted environmental impacts (e.g. spray drift), and maximising productivity while minimising cost. Over the last decade, there has been a proliferation of relatively small, battery-powered, multi-rotor uncrewed aerial spraying systems (UASS) but their use to date in New Zealand forestry has been limited. This paper assesses the potential role of UASS in forest management and, where opportunities exist, identifies barriers slowing their adoption. Methods: Publications on spray application in New Zealand forestry and use of UASS in both New Zealand and internationally were identified by conducting a Google Scholar literature search using a range of relevant keywords, and the retrieved studies were reviewed systematically. Unpublished reports from the New Zealand Forest Research Institute Ltd and Forest Growers Research Ltd were also considered. Information from the reviews was assessed critically, synthesised, and used to evaluate several potential forestry use cases for UASS. Results: Several potential use cases for UASS were identified along with a set of research and development needs to support and accelerate the adoption of UASS into forest management operations and to provide regulators with the means to apply appropriate risk management measures. Based on the literature analysis, the opportunity for UASS, at least in the near term, is to realise the concept of ‘precision spraying’ rather than to replace conventional aircraft carrying out broadcast applications over large areas. Conclusions: Recent UASS technology improvements have provided the potential for a step-change for at least some pesticide application niches within New Zealand forestry. Significant opportunities for UASS in forestry include herbicide spot spraying, treatment of boundaries close to sensitive areas, low-volume fungicide or insecticide applications, especially for small areas or in pest eradication operations; and applying variable treatments to individual plants or zones within a target area defined by remote sensing tools. A coordinated research and development programme is needed to optimise UASS use and to provide performance data to underpin regulatory processes.
Copyright (c) 2024 Brian Richardson (Author) http://creativecommons.org/licenses/by/4.0
New probability density function for biopopulations modelling
Background: Biological populations were studied to understand their ecology and to evaluate the relationships between living beings that comprise them. Mathematical functions used in probabilistic models should present multifunctionality, sensitivity, and flexibility to appropriately describe a natural phenomenon. The objective of this study was to develop a new probabilistic distribution with five parameters to maximize its flexibility and ensure a better goodness of fit when compared to other important distributions, such as Beta, Burr, Silva and Pareto. Methods: New distribution estimators were derived using the mathematical expectation of central and dispersion moments. Estimated values of the parameters were obtained using an optimization process developed by Abel Soares Siqueira, research software engineer at the Netherlands eScience Center in Amsterdam. Data for the application of the developed distribution method were collected at different sites in Brazil, where asymmetry and kurtosis were detected. Results: The Pellico-Behling Probability Distribution (5P) was applied to fit the datasets for Cariniana legalis, Acacia mearnsii, and Eucalyptus saligna. For the average mortality of 124 species, it was used with (4P). The distribution fitted to sampled datasets was compared with the fitted Beta and Burr (4P) distributions, except for Silva’s polynomial distribution that was fitted to the heights of the species Eucalyptus saligna and the Pareto distribution to mortality of 124 tropical species from a fragment of a semideciduous seasonal forest, to evaluate and verify its potential and robustness. Conclusions: The new distribution with five parameters is flexible and produced better goodness of fit than those obtained from the other distributions used for comparative purposes.
Copyright (c) 2026 Sylvio Péllico Netto, Alexandre Behling (Author) http://creativecommons.org/licenses/by/4.0
Uniformity measures for young Eucalyptus sp. plantations using attributes extracted from UAV flights
Background: Studies show that forest uniformity has a direct correlation with productivity, and uniformity measures can serve as indicators of the silvicultural quality of plantations. In this context, this work aimed to determine uniformity and survival in young Eucalyptus sp. plantations using attributes obtained from passive sensors boarded on Unmanned Aerial Vehicles (UAV). Methods: Tree height was underestimated by the UAV compared to those measured in the Quality Forest Inventory (QFI). Thus, a correction factor applied to size classes was proposed to estimate these heights. The plantations’ uniformity was obtained through the uniformity indices (UI). The UIs were spatialised and integrated, resulting in two uniform surfaces, with and without planting failures. Results: The UAV survival estimates did not show significant differences compared to the inventory estimates at the 1% or the 5% significance levels. The classification of uniformity surfaces showed that the Eucalyptus saligna Sm plantation was the least uniform compared to the E. grandis W. Hill × E. urophylla S. T. Blake plantations. Conclusions: Measures of survival and uniformity by the UAV can be jointly employed to generate uniformity surfaces and to determine the areas that need more attention from silvicultural management.
Copyright (c) 2025 Adriane Avelhaneda Mallmann, Ana Paula Dalla Corte, Alexandre Behling, Rubén Manso, Kauana Engel, Claiton Nardini, Iací Dandara Santos Brasil, José Augusto Spiazzi Favarin, Jonathan William Trautenmüller, Gabriel Agostini Orso (Author) http://creativecommons.org/licenses/by/4.0
Forest-fire interactions, impacts, and implications: a focus on mangroves
Background: Fire plays a key role in the world’s wetland ecosystems, affecting the fundamental aspects of their ecological functioning. The increased frequency of wildfires continues to exert a significant influence on the succession of mangrove ecosystems and the spatial distribution of species. Numerous studies have attempted to highlight the effect of fires on forest ecosystem function and integrity; however, the results are inconclusive. In particular, it remains uncertain whether forest fires have direct impacts and implications on mangrove ecosystems, a forest type known for its distinct characteristics and low ignition rates due to high moisture levels. Methods: We have conducted a comprehensive review of over 120 relevant scholarly articles found through formal searches of literature and citation databases and by surveying relevant publications to identify and examine the interactions, prevalence, and implications of forest fires in mangrove ecosystems globally. We have also synthesised the impacts of recurrent fires on the numerous ecological goods and services offered by mangroves and highlighted the existing literature gaps and directions for future research. Results: Mangrove forest fires are prevalent in many countries across the world with varying distributions of forested areas. While there are numerous causes of wildfires in mangroves, most occurrences are due to a combination of natural dry periods (El Niño events) and anthropogenic activities, which may deliberately or accidentally increase fire regimes. There are many negative effects of mangrove forest fires which can affect the goods and services provided to the environment and society, including habitat loss, pollution, and wildlife destruction. However, our findings have highlighted some cases where wildfires have positive effects on mangrove ecosystems by encouraging nutrient enrichment and habitat expansion. Our review reports numerous literature gaps with high priorities for future research on understanding sustainable forest management with the coexistence of fires through preservation, conservation, and public awareness. Conclusions: Forest fires are prevalent in mangrove ecosystems due to a combination of natural phenomena and human-induced factors. With predominantly negative effects, forest fires result in a loss of ecological integrity, leading to severe economic losses and habitat degradation. Emphasis should therefore be placed on sustainable forestry and public awareness for the mitigation of the dynamic effects of forest fires on mangrove ecosystems.
Copyright (c) 2025 Sabrina Dookie, Professor Abdullah Adil Ansari, Dr. Sirpaul Jaikishun (Author) http://creativecommons.org/licenses/by/4.0
Total plant biomass, carbon stock, and species- and age-specific allometry for 12 of New Zealand’s early-colonising indigenous shrub and tree species to 5 years of age
Background: Changes in biomass and carbon stocks of open-spaced plantings are important considerations in the restoration of biodiversity and ecological function of New Zealand’s degraded (non-forested) landscapes and streamside margins. Species- and age-specific allometric relationships of biomass and carbon stocks were developed for a diverse range of indigenous seral shrub and tree species during their juvenile growth period. Methods: Whole plants of Coprosma robusta Raoul (karamu), Plagianthus regius (Poit.) Hochr. (lowland ribbonwood), Sophora tetraptera J.S.Muell. (eastern kōwhai), Pittosporum eugenoides (Cunn.) (lemonwood), Pittosporum tenuifolium (Gaertner) (kōhūhū), Hoheria populnea A.Cunn. (North Island lacebark), Myrsine australis (A.Rich) Allan (māpou), Pseudopanax arboreus (Murray) Philipson (fivefinger), Cordyline australis (G. Forst.) Endl. (cabbage tree), Knightia excelsa (R.Br.) (rewarewa), Leptospermum scoparium (J.R.Forst. & G.Forst (mānuka), and Coriaria arborea (Linds) (tree tutu) were planted as 2-year-old nursery-raised seedlings in a plot-based field trial. Plants of each species were destructively sampled annually over 5 consecutive years and species-specific allometric equations developed for foliage, branch, stem, total above-ground biomass (AGB), total below-ground biomass (BGB), and whole plant biomass to calculate carbon stocks. Results: In each year and for each of the 12 test species, root-collar diameter over bark (RCD) gave the best fit for plant height, foliage, branch, stem, total AGB, total BGB, and whole plant biomass. At age 5 years, Coriaria arborea and Cordyline australis accumulated significantly more AGB (P = 0.05) than the remaining species, none of which were not significantly different from one another and each species had allocated more than 20% of their total biomass to BGB, with BGB:AGB ratios of between 0.24 and 0.44. Species-specific mean tree biomass values at this age ranged from 0.5 to 14.0 kg per plant. The planting of equal numbers of the seven best-performing species as 2-year-old seedlings could potentially amass a carbon stock of 13.1 t CO2 1000 stems ha-1 within 3 years after establishment as open-spaced plantings. Conclusions: RCD proved to be a reliable predictor of plant height, foliage biomass, branch biomass, stem biomass, total ABG, total BGB, and whole plant biomass. Optimisation of the carbon potential amassed by mixed plantings of indigenous seral plants will require the development of allometric equations for a wider range of species best suited to restoring ecological integrity to degraded landscapes and to improve the accuracy of existing biomass and carbon stock inventories.
Copyright (c) 2025 Michael Marden, Norman William Herbert Mason, Suzanne Lambie, Donna Rowan (Author) http://creativecommons.org/licenses/by/4.0
Modelling above-ground biomass of Eucalyptus bosistoana F.Muell. and Eucalyptus globoidea Blakely
Background: Estimation of forest biomass has become critical as afforestation has been proposed to sequester carbon from the atmosphere in order to mitigate climate change. New Zealand Dryland Forestry Innovation (NZDFI), in collaboration with the University of Canterbury’s School of Forestry and the Marlborough Research Centre, has initiated a research and development programme to gather seed, breed, propagate, identify site limitations, model growth, investigate silviculture, and develop wood products from a suite of eucalypts that grow durable heartwood. The aim is to supply naturally durable wood for uses that formerly required either imports of durable wood or copper-chrome-arsenate treated pine. Methods: As part of a project examining land-use and greenhouse gas budget case studies in Marlborough, New Zealand, we collected and summarised data describing above-ground biomass (AGB) of Eucalyptus bosistoana F.Meull., and Eucalyptus globoidea Blakely trees across a wide range of combinations of height (h) and diameter at breast height (dbh). One hundred and eleven trees were felled, separated into stems, branches and foliage, and the components were weighed in the field. Subsamples of these tree parts were collected and weighed in the field after separating bark from stem discs. The subsamples were dried in an oven at 105°C, and then weighed. Ratios of dry to wet weights for samples were applied to total green weights from the field in order to calculate AGBs of tree components. Systems of non-linear equations were simultaneously fitted to the data to ensure additivity; that sums of estimates of tree part AGBs versus dhb, h and slenderness (h/dbh) equalled estimates from a model of total tree AGB versus the same independent variables. The study also included the development of a plot-level estimation model of above-ground CO2-e/ha for E. globoidea and its incorporation in an on-line growth and yield simulator. Moreover, a comparison of two pathways to estimating AGB by aerial LiDAR was made: One including estimates of dbh and h from LiDAR and applying the tree-level equations developed in this study, and one going directly from LiDAR metrics to estimates of AGB. Results: A system of models created for both species with a dummy variable denoting species yielded the least biased residuals, with 22 coefficients estimated in one simultaneous fit. Standard errors varied with plant part and with the size of the prediction, requiring transformations prior to fitting. R2 values also varied with part, but were typically between 0.96 and 0.98. An exception was foliage and seeds which were influenced by one tree with an unusually high loading of seeds. The standard error for plot level estimates of CO2-e was 1.9 tonnes CO2-e /ha and residuals were relatively unbiased. Directly predicting individual tree AGB from LiDAR metrics yielded less biased estimates than predicting dbh and h and then using those estimates to predict AGB. Conclusions: A system of related, additive equations with a dummy variable denoting species represented the above-ground biomass of Eucalyptus globoidea and Eucalyptus bosistoana with precision adequate for prediction of biomass for fuel and carbon storage to mitigate climate change. Direct predictions of biomass from LiDAR metrics were less biased than predictions of biomass from tree height and diameter at breast height that were in turn predicted from LiDAR metrics.
Copyright (c) 2025 Euan G. Mason, Paul Millen, Ash Millen, Ruth McConnochie, Meike Holzenkaempfer, Monika Sharma, Alex Chamberlain, James Burns, Thomas Copeland, Sebastien Lallemant, Christophe Robert, Georgia Kennedy (Author) http://creativecommons.org/licenses/by/4.0
Potential of high- or low-solubility calcium to correct stem sinuosity in fast-growing Pinus radiata D. Don
Background: Pinus radiata D. Don is widely planted in Chile due to its fast growth and adaptability to various soil types and environmental conditions. However, the species is prone to stem sinuosity due to factors such as genetics, environmental stresses including nutrient availability, and management practices. This study assessed the efficacy of either low- or high-solubility calcium (Ca) additions in reducing stem sinuosity in young radiata pine plantations grown on Andisols. Methods: We compared growth and stem sinuosity of a 3-year-old pine plantation subject to two types of Ca sources: agricultural low-solubility crushed lime (ag-lime), and finely ground pelletised high-solubility lime (pell-lime), applied at three concentrations (300 kg Ca ha-1, 600 kg Ca ha-1, 1,200 kg Ca ha-1) alongside a control. Results: Our findings revealed that both calcium sources increased the soil Ca content post-application but was only significant for the highest concentration in each case (1,200 Kg Ca ha-1). The soil Ca availability rate was higher in pell-lime treatments. Agricultural lime had no effect on growth, whereas two of the pell-lime treatments increased the basal area, the lowest concentration increased the cumulative diameter at the root collar, and the highest concentration reduced tree height. Interestingly, while pell-lime did not mitigate stem sinuosity in 3-year-old pine trees, ag-lime reduced stem sinuosity severity although this result was not correlated with soil Ca content. Notably, the ag-lime treatment at 600 kg Ca ha-1 was most effective, decreasing the proportion of severely deformed trees from 32% to 14%. Conclusions: The application of both low-solubility calcium (ag-lime) or high-solubility calcium (pell-lime) calcium increased the soil Ca content. Ag-lime treatments showed no adverse impact on stand growth and led to a reduction in stem sinuosity being the most effective treatment applying 600 kg Ca ha-1. Pell-lime treatments had mixed effects on growth: diameter at root collar (DRC) and basal area increment (BAI) increased, and height decreased. Pell-lime treatments did not reduce stem sinuosity. Our results suggests that stem sinuosity might be more closely associated with deficiencies in trace metals like Cu and Mn rather than Ca content alone.
Copyright (c) 2025 Claudia Garrido-Ruiz, Rafael Rubilar, Daniel Bozo, Matías Pincheira, Alvaro Zapata, Oscar Jara, Rachel Cook, David Carter, Timothy Albaugh, Otavio Campoe (Author) http://creativecommons.org/licenses/by/4.0
Germination dynamics of Nothofagus glauca seeds: provenance-specific responses to temperature variation
Background: The influence of temperature on seed germination is crucial, and climate change effects on plant distribution are significant. To grasp climate change’s impact on terrestrial ecosystems, understanding plant adaptation to temperature shifts is vital. Nothofagus glauca, a vulnerable species endemic to Chile’s Mediterranean region, is the most representative species of South American Mediterranean forests. Methods: Seeds of N. glauca were collected from two Andean provenances during mast years (2017, 2022) and processed according to the standards of the International Seed Testing Association (ISTA). Germination experiments were conducted under controlled laboratory conditions in the absence of light, testing four temperature levels (18°C, 22°C, 26°C, and 30°C) and two provenances (El Colorado, located further north, and San Fabian, located further south). Seeds were pretreated with gibberellic acid to break physiological dormancy, and germination parameters were assessed over a 40-day period. Results: Temperature had a significant impact on germination process, although the effect varied by provenance. The optimal germination capacity temperature was 22°C for the northern origin and 26°C for the southern origin. In both provenances, germination capacity remained relatively high at temperatures of 18°C and 30°C, suggesting that these temperatures did not approach the minimum or base and maximum or ceiling temperature thresholds. Furthermore, no clear trend was observed in the germination start day for either provenance. Significant differences were observed in average germination speed and germination vigour between the two provenances. Considering all variables, the optimal temperature differs between them (22°C for El Colorado and 26°C for San Fabian). Conclusions: Temperature’s pivotal role in germination and diverse provenance responses highlight potential impacts on genetic distribution and conservation. Understanding provenance-specific adaptation to changing climates is essential for comprehending climate change’s effects on terrestrial ecosystems. Tailoring conservation approaches to distinct provenances, like N. glauca, is crucial. This approach can effectively tackle climate change challenges and protect vulnerable species.
Copyright (c) 2025 Rómulo Santelices-Moya, Antonio Cabrera-Ariza, Cristian Bovadilla-Bustos, Miguel Peralta-Aguilera, Patricio Ramos, Rafael Navarro-Cerrillo (Author) http://creativecommons.org/licenses/by/4.0
Variations in the hierarchical architecture of Nothofagus obliqua: evidence from juvenile naturally-regenerated trees and from seedlings obtained by controlled crosses of selected individuals
Background: Many tree species with potential for wood production present high intra-specific variations in the extent of trunk differentiation (i.e. hierarchical architecture). The identification of multiple-scale traits related to hierarchical architecture could improve selection criteria for domestication. Methods: We investigated the hierarchical architecture of Nothofagus obliqua, a valuable species for timber production, but with high structural variability. Young trees in even-aged natural regeneration gaps, and seedlings derived from controlled crosses and open pollination were studied. For the second approach, trees with contrasting degree of hierarchical architecture were manually crossed. In both, juvenile plants and seedlings, we analyzed trunk growth unit traits and hierarchical architecture indices based on the relative size and branching angle of main branches. Results: In regeneration gaps, hierarchical architecture was positively related to height and diameter. Apex persistence, the number of sylleptic branches and mean internode length were indicative of larger and more hierarchical trees. Some support is provided to the idea that adult trees with a notably hierarchical architecture could produce young trees with early signs of a hierarchical architecture. In seedlings, hierarchical architecture was negatively related to basal diameter. Conclusions: Some growth unit traits that differed among progenies and were related to hierarchical architecture could be considered for the development of selection criteria for young trees.
Copyright (c) 2025 Cristian Daniel Torres, Amaru Magnin, Leonardo Ariel Gallo, Marina Stecconi, Mariana Salgado, Claudia Maricel Sosa, Teresa Schinelli Casares, Javier Guido Puntieri (Author) http://creativecommons.org/licenses/by/4.0
Diameter distributions and spatial distribution patterns of tree species are important for planning sustainable management in natural forests in the eastern Amazon
Background: Do tree species that have wood of high commercial value which are being extracted in the Saracá-Taquera National Forest have diameter and spatial distribution patterns that enable continuous production of timber to meet the criteria of ecological conservation and sustainable management of their populations? To answer this question, we evaluated diameter and spatial distributions of 15 commercial tree species of ecological and economic importance, in a concession area in the Saracá-Taquera National Forest, Eastern Amazon. Methods: The data were obtained from a forest inventory carried out in 24 50 m × 50 m plots, considering a minimum diameter of 30 cm. The 15 species were selected based on three criteria: importance value index; volume stock; and commercial value of the wood. The trees were distributed into diameter classes with an interval of 10 cm between them to analyse the diameter distribution. The spatial distribution patterns of the species were analysed using the univariate Ripley’s K function. Results: The results showed that the presence of large trees and the aggregated spatial distribution in most of the tree species studied may determine the feasibility of continuous timber production to meet conservation and sustainable management criteria. The spatial distributions of stocks should guide planning of forest management activities, including pre-logging, logging and post-logging activities. However, the low population density of most species suggests that logging must be well planned to avoid population declines. Although forest management on a sustainable basis has advanced substantially in recent years in the Amazon, the factors that promote different diameter and spatial distributions of species are still considered complex and little studied. Conclusions: The results point to a need to expand research on this topic in managed areas, including the same technological approach as the work described here. This type of analysis can constitute an important tool for defining population management strategies for each species, considering their ecological characteristics and environmental adaptation at a local level.
Copyright (c) 2025 Quétila Souza Barros, Evandro Ferreira da Silva, Nívea Maria Mafra Rodrigues, Brenda Letícia Rodrigues, Adriano Ribeiro de Mendonça, Gilson Fernandes da Silva, João Olegário Pereira de Carvalho, Tatiana da Cunha Castro, Marcus Vinicio Neves d'Oliveira, Erica Karolina Barros de Oliveira, Jeferson Pereira Martins Silva, Quinny Soares Rocha (Author) http://creativecommons.org/licenses/by/4.0
A qualitative study of the machine operator’s experience of wellbeing in the New Zealand logging industry
Background: Prompted by the need to reduce exposure to the physical hazards of the logging workplace, more of Aotearoa New Zealand’s loggers now find themselves operating a machine rather than working ‘on the ground’. This change has enabled more production to be achieved with less workers and with a significant reduction in the rate of serious harm incidents. However, mechanisation is not without its risks to operator wellbeing. This study explores the wellbeing of operators and the psychosocial demands and coping adaptations that contributed to that experience. Methods: Twenty-seven operators were recruited from three regions to participate in a semi-structured interview to explore their experiences of stress and wellbeing. References with consistent meaning were first, coded, and then, using Axial Coding, themes or categories were identified. Defining properties for each of these categories were then used to conceptualise the relationships between the themes. Results: Stress and wellbeing were described as a specific set of experiences resulting from the adaptations participants made in the face of threats to production, a sense of place within the crew and to family wellbeing. Those adaptations were arranged in two pathways that were dependent on what resources were available to the participants. If left entirely to their own skills and time, the participants would cope with threats by working longer hours. If through the decisions their forest owner / manager and contractor made, they had access to sufficient supply chain capacity, work security and job control supported by an effective organisational culture and interpersonal relationships, they could access the work-life balance that was at the heart of their sense of wellbeing. Conclusions: This research has provided an inventory of the psychosocial hazards faced by logging machine operators working in Aotearoa and the resources that enable them to cope. In doing so it has suggested that the potential for operator wellbeing is established in the designing of the overall supply chain (skids, roads, logging equipment configuration, and truck capacity) and the contracts that connect the various services, and then achieved through the way logging businesses are led and managed.
Copyright (c) 2024 Trevor Best, Rien Visser (Author) http://creativecommons.org/licenses/by/4.0
Assessing the impacts of experimental mid-rotation forest fertiliser treatments on water quality
Background: Planted forests face on-going challenges to increase productivity while remaining within sustainable limits. Forest management activities that potentially impact on water quality are under increasing public scrutiny and regulatory controls. New Zealand’s forest industry is experimenting with aerially applied, mid-rotation fertiliser treatments as a sustainable option to increase productivity from planted forests. However, the effect of such applications on water quality requires investigation. Methods: Field trials were established to assess the effects of two conventional fertiliser applications (either granular di-ammonium phosphate (DAP) or granular urea) and a new-to-forestry liquid foliar fertiliser blend, on nitrogen and phosphorus concentrations in stream water of three planted forest sites representing a range of New Zealand climatic and soil environments. Results: Overall, the liquid foliar fertiliser treatment had the least impact on water quality compared with the two conventional fertiliser treatments. On the day of fertiliser application, when compared with pre-treatment in-stream concentrations, the urea treatments resulted in short-term increases in total nitrogen. The DAP treatment increased total phosphorus and dissolved reactive phosphorus concentrations with peak concentrations declining within hours. In the post-application period, any increases in nutrient concentrations in stream water were mainly associated with rainfall events within six months of application and at one site, the resumption of stream flow following a dry spell. Riparian ‘no-spray’ buffers of varying widths assisted in mediating the impacts of fertiliser applications. Conclusions: Initial evidence from these trials indicates that mid-rotation fertiliser treatments have the potential to provide an alternate management option to increase forest productivity or disease resilience with minimal or only short-term effects to water quality. However, further research on their environmental effects would support the development of guidelines specific to mid-rotation fertiliser applications, particularly if mid-rotation fertiliser applications become standard management practice in the forest industry.
Copyright (c) 2024 Brenda R. Baillie, Joane S. Elleouet, Graham W. R. Coker (Author) http://creativecommons.org/licenses/by/4.0
Assessing native woody composition, structure, and carbon stocks along elevation-climate gradients in mature Pinus radiata plantations as a baseline for transitional forestry: a regional pilot study
Background: The ecological science associated with transitioning exotic forest to native dominance (hereafter transitional forestry, transition forests) is currently limited, yet this form of forest has expanded rapidly. In part, this is related to forest-based carbon credit schemes which have driven large-scale afforestation in exotic trees. In other circumstances (e.g., for soil conservation or values-based reasons such as biodiversity conservation), forest owners wish to transition their exotic forest to native forest without harvest. Knowledge is required to inform management of realistic expectations for regeneration and succession both spatially and temporally. Methods: Mature (>20-year-old) Pinus radiata plantations were surveyed along three elevation-climate gradients in the Waikato region of New Zealand to explore the composition and structure (including native carbon stocks) of plantation understories and whether these parameters vary spatially over several decades. Mammalian browsing was also recorded. Results: Native woody stem densities were variable. Factors indicated as driving variability were stand age, elevation, topographic shelter, soil hydrology, solar radiation, and air temperature. On average, understories comprised five native woody species in the seedling tier, a single native species in the sapling tier, and a single native species in the tree tier. The most common species were the sub-canopy tree species Melicytus ramiflorus, Geniostoma ligustrifolium, and Aristotelia serrata. Tall old-growth species, such as Beilschmiedia tawa, Podocarpus totara, Pectinopitys ferruginea, and Prumnopitys taxifolia, occurred in only particular circumstances and on average at densities too low to form a meaningful part of a future forest canopy. Average species richness was low, although some diversity hotspots occurred. Carbon stocks in native trees and tree ferns in the understories were on average 1.55±0.38 tCha–1. Heavy browsing by mammalian herbivores was recorded at 60% of plots. Conclusions: These data indicate typical understorey conditions in mature P. radiata plantations for this area of New Zealand in the absence of management to promote a native transition. These data also highlight the importance of browser control, enrichment planting of tall old-growth species, and canopy manipulations to accelerate regeneration and succession in non-harvest P. radiata plantations. The data suggest transitional forestry should only be attempted at scales that can be reasonably managed, and there is a need for caution against large-scale establishment of P. radiata for transitional forestry as at large scales, achieving adequate levels of management are uncertain.
Copyright (c) 2025 Adam Sean Forbes (Author) http://creativecommons.org/licenses/by/4.0
Use of nitrogen-fixing plants to improve planted forest soil fertility and productivity in New Zealand: A review
Background: Planted forests with low fertility soils are likely to require increased inputs of nitrogen (N) to satisfy increasing productivity demands. The use of N fertilisers will become more challenging due to their increasing cost and the risk of unwanted environmental impacts. Nitrogen-fixing plants may provide an alternative option to chemical fertilisers that is not only cheaper but has a lower greenhouse gas footprint. Methods: Information on N-fixing plants was collated from available literature, focusing on species previously associated with planted forests as well as other exotic N-fixing trees and New Zealand native plants not used in commercial planted forests. Results: Benefits to planted forest growth in New Zealand by N-fixing plants have been proven in only a few cases. Lupinus arboreus Sims was used in the 1970s and 1980s to increase N inputs in a planted Pinus radiata D.Don coastal forest, and improved P. radiata productivity was demonstrated. Productivity gains ceased when a blight disease infected the lupin population. Many N-fixing plants have been shown to tolerate low fertility soils and establish in planted forests, but there is limited information on their N contribution to the soil, and whether this N contribution increases P. radiata productivity. Such N-fixing plants include Lotus species, clover (Trifolium species) and weeds such as gorse (Ulex europaeus L.) and broom (Cytisus scoparius (L.) Link), which are commonly found in association with P. radiata forests. New Zealand native N-fixing shrubs may be suitable but there is limited information available describing N-fixation or forestry management for native plant species. Conclusions: Nitrogen-fixing plants are a valuable resource, which when managed properly could be used for enhancing productivity. Issues with pests and disease, and limited knowledge regarding the management of N-fixing species, restricts adoption in planted forests. Well-designed research is needed to assess impacts on whole forest system N cycling as well as selection of appropriate plant species for use in planted forests without unintended consequences such as competition for soil moisture or light. This research needs to be integrated with forest management and delivered as practical options to ensure success.
Copyright (c) 2024 Nicola M. Reid, Kathryn Wigley, Aysha Nusrath, Simeon J. Smaill, Loretta G. Garrett (Author) http://creativecommons.org/licenses/by/4.0
Evaluation of forest areas and land use/cover (LULC) changes with a combination of remote sensing, intensity analysis and CA-Markov modelling
Background: Land use and land cover change (LULC) is crucial for maintaining the integrity of ecosystems’ structure and function, and thus regular measurement and monitoring of LULC are necessary. Methods: In this study, the temporal and spatial changes in forest areas and land cover in the province of Sinop, located in the north of Turkey, were analysed by intensity analysis for two 10-year periods from 2002-2012 to 2022, and 2032 and 2042 forecast LULC maps were generated using the cellular automata CA-Markov model. In the study, datasets were prepared using forest type maps and Landsat images, and the images were classified using various classification techniques. Results: The results indicated that forest areas increased by 23% (37,823.38 ha) from 2002 to 2022, with the mixed forest category showing a decrease of 22% (12,245.43 ha) within this. In non-forest areas, a significant increase of 72% was observed in the settlement category, while a decrease of 63% was noted in the agricultural category. According to the intensity analysis, the rate of change in LULC is faster from 2002 to 2012 than from 2012 to 2022. In both periods, the settlement and agricultural categories have predominantly targeted each other’s losses. According to the simulation results of land use/cover from 2022 to 2042, a 0.50% increase in total forest area, a 2.87% increase in settlements, and a decrease of 2.65% and 0.71% in agriculture and water classes, respectively, are anticipated. Conclusions: The overall results suggest that it can contribute to setting an appropriate development goal, especially for forest planners and policymakers, to regulate land use changes to achieve higher carbon stocks and maintain balance in global climate scenarios.
Copyright (c) 2024 Hasan Aksoy (Author) http://creativecommons.org/licenses/by/4.0
Effects of container size and growing media on growth of argan (Argania spinosa) seedlings in Morocco
Background: Argan (Argania spinosa) is an important arid species in Morocco, hence the need to undertake nursery practices that promote its regeneration and sustainability in a vulnerable environment. This study aimed to examine the effect of container size and growing medium on morphological traits, biomass, as well as root morphology of one-year-old argan seedlings in the Marrakech region of Morocco. Methods: Three container sizes of 300, 400, and 500 cm3 were selected in which seven types of growing media with varying proportions of acacia compost, crushed cypress cones, Barbary thuja, eucalyptus capsule composts, and potting soil were used. Subsequently, measurements of plant growth variables and biomass, as well as identification of root deformations were carried out. Results: Our results show that container size and growth medium strongly influenced (p < 0.001) morphological traits and biomass of argan seedlings. Growth was highest in seedlings grown in the 500 cm3 container on substrates composed of both 100% acacia compost and 50% potting soil + 50% acacia compost, while it was lowest in seedlings in the 300 cm3 container with the compost composed of a mixture of equal proportions of cypress and Barbary thuja, and eucalyptus. While the main root deformities were hooked roots (14.1%) and root eccentricity (13.0%), seedlings with multiple deformities were by far the most common (38.4%). The size of the container did not seem to influence their occurrence, whereas about 35% of the deformations were observed in seedlings grown on substrates composed of mixtures of potting soil and acacia compost, cypress cones, and Barbary thuja and eucalyptus composts. Conclusions: This study shows the importance of adopting an adequate protocol to allow the regeneration of forest species with the necessary characteristics to survive the often-challenging environmental conditions prevailing not only in southern Morocco but also across most of the country.
Copyright (c) 2024 Youssef Dallahi, Amal Boujraf, Abdelaziz Smouni, Mouna Fahr, Ahmed El Aboudi, Collins Ashianga Orlando, Kamal Laabou, Abderrahim Ferradous, Mohamed Mahmoud Ould Abidine (Author) http://creativecommons.org/licenses/by/4.0
Diversity and growth patterns of woody species in the Mediterranean Coastal range of Chile: A case study in Altos de Cantillana
Background: The Altos de Cantillana mountain range (ACMR) in central Chile is composed of different vegetation communities, and is currently a priority site for conservation, due to its high endemism, high anthropogenic pressure and vulnerability to climate change. Research on biodiversity and carbon stocks in ACMR is essential to comprehend the resilience of these forests and to define conservation strategies. This study examines the spatial variability of biodiversity and tree biomass patterns along the entire altitudinal gradient of the ACMR. Methods: Six tree species communities were studied in Altos de Cantillana Nature Sanctuary, along an altitudinal gradient ranging from 415 to 2010 m. Woody species regeneration and inventory plots, as well as dendrochronological sampling in ~150 trees were carried out. Diversity patterns were analyzed using the Jaccard index and alpha index. Growth patterns of dominant trees species were analyzed by ring-width and trunk biomass chronologies, focusing on the recent megadrought period since 2010. Results: The forest inventory revealed a notable decline in alfa diversity patterns with increasing elevation. The moist sclerophyllous forest exhibited the highest diversity. However, we did not find a pattern between elevation and diversity (and abundance) at the seed regeneration inventory level. Additionally, we identified three clusters of woody species similarity: (i) sclerophyllous, shrubs and hygrophilous forest (<1,000 m.a.s.l.); (ii) high-elevation sclerophyllous forest (>1,500 m.a.s.l); and (iii) deciduous forests (~ 2,000 m.a.s.l). Furthermore, declining growth rates were observed in all communities studied beginning in the 1980s, with even a stronger reduction in radial growth (35% on average) and biomass accumulation (56% on average) when comparing the megadrought with six decades earlier. Conclusions: We concluded that there is a negative correlation between woody species diversity and elevation. However, there are no altitudinal patterns in seedling regeneration diversity and abundance, which puts the natural succession in ACMR at risk. Additionally, we have determined that the accumulation of trunk biomass in dominant woody species has been significantly impacted by the recent megadrought period. This has affected the sink capacity of forest communities in ACMR. Therefore, our findings can significantly contribute to more efficient and timely decision-making processes regarding the conservation and restoration of this globally unique ecosystem.
Copyright (c) 2024 Stephanie Gibson-Carpintero, Anahi Ocampo-Melgar, Alejandro Venegas González (Author) http://creativecommons.org/licenses/by/4.0
A broad analysis of vegetative rescue and propagation of Moquiniastrum polymorphum (Less.) G. Sancho
Background: The primary method for propagating forest species is through seeds, which is cost-effective and ensures genetic adaptability to environmental changes. However, germination issues and genetic variability can hinder standardisation of productivity. In the case of Moquiniastrum polymorphum, a species known for its remarkable wood quality and pharmacological potential, seedling production and genetic improvement efforts have been limited. This study focused on the rescue and vegetative propagation of M. polymorphum, which are crucial steps for species selection and genetic enhancement. Methods: Protocols were tested to rescue and propagate propagules from different individuals collected in Lages, Santa Catarina (2020/2022). The vegetative rescue tests were: (I) epicormic sprouting induction through girdling techniques and detached branches; and (II) influence of individuals, disposition sense and time on the epicormic sprouting of detached branches. Vegetative propagation analyses included: (I) cutting according to individuals; and (II) relation between rooting environments and individuals on cutting. Results: The results indicated that the girdling techniques were not efficient for vegetative rescue, as only 8% of individuals produced epicormic sprouts. In contrast, detached branches showed a much higher success rate of 80% for epicormic sprouting, revealing significant differences in sprout development among individuals over time. Vertically oriented branches produced nearly three times more sprouts compared to horizontally oriented branches. Regarding vegetative propagation, certain individuals exhibited remarkable rooting rates of over 75%. However, no conclusive results were obtained when using epicormic materials or when considering different rooting environments. Conclusions: Given the significance of rescue and vegetative propagation in plant genetic improvement and the limited research addressing these aspects in M. polymorphum, this study holds substantial importance for future investigations. It is recommended to expand rescue and vegetative propagation studies to encompass additional populations, different individuals, and rooting environments, further advancing our understanding and efforts to enhance this species.
Copyright (c) 2024 Alexandra Cristina Schatz Sá, Bruno Nascimento, Bruno Jan Schramm Corrêa, Guilherme Neto dos Santos, Marcio Carlos Navroski, Luciana Magda de Oliveira, Adelar Mantovani, Mariane de Oliveira Pereira (Author) http://creativecommons.org/licenses/by/4.0
Seed thermo-priming accelerates the growth of Ceiba glaziovii (Kutze) K.Schum. seedlings
Background: Global climate changes have caused temperature increases that can harm plant development, especially the initial growth and establishment of seedlings for the recovery of degraded areas. However, there are species in which these losses are attenuated when the seeds are thermo-primed to sublethal temperatures. Therefore, the objective of the present study was to evaluate the influence of seed heat conditioning on germination and initial growth of Ceiba glaziovii (Kuntze) K. Schum seedlings, an endemic species occurring in seasonally tropical dry forest in Brazil. Methods: Seeds of C. glaziovii were exposed to 70 oC for 15, 30, 45, 60 and 90 minutes as pre-germination treatments. The control did not undergo heat treatment. Germination variables, vegetative growth, survival rate and normal leaves were evaluated. Results: Thermo-priming negatively affected the germination proportion of C. glaziovii seeds with increasing exposure time. However, it significantly enhanced vegetative growth and seedling survival rate of this species after transplanting, without impairing the formation of normal leaves. Conclusions: Thermo-priming of seeds was found to produce more vigorous seedlings of Ceiba glaziovii.
Copyright (c) 2024 José Laurindo dos Santos Júnior, Elizamar Ciríaco da Silva (Author) http://creativecommons.org/licenses/by/4.0
Mid-term results and prospects for irregular shelterwood systems in hardwood-dominated temperate rainforests in Chile
Background: When possible, silviculture should aim to develop mixed-species multi-aged forests that can be more productive and resilient to disturbances, provide high-quality timber and sustain greater amounts of biomass. Southern Chile is covered by temperate rainforests dominated by a mixture of tree species, such as the Evergreen forest type (EFT). The irregular shelterwood regeneration method is a novel approach aimed at developing irregular multi-aged forests following the retention of the residual forest (no final cut). Here, we report mid-term results after implementing these cuttings in two EFT forests in the Coastal Range and discuss its prospects for other temperate rainforests. Methods: Two forests were sampled and evaluated in terms of composition, structure and growth, focusing on the new cohorts developed or released after the irregular shelterwood cuts. One forest was cut in a low-productivity site at 600 m (Hueicolla) in 1983, and the other in a medium-productivity site at 350 m (Llancahue) in 2009. In Hueicolla, 63% of the basal area was harvested from an old-growth forest where the main residual tree species were Eucryphia cordifolia, Laureliopsis philippiana and Saxegothaea conspicua. In Llancahue, 40% of the total basal area was harvested in a mature secondary forest dominated by Nothofagus dombeyi. Results: The understorey developed in Hueicolla had 3,600 trees per ha and a quadratic stand diameter of 15 cm. It was dominated by the mid-tolerant species Eucryphia cordifolia, Gevuina avellana and Lomatia ferruginea, plus the shade-tolerant Amomyrtus luma. In Llancahue, a dense lower canopy was dominated by Podocarpus salignus and Drimys winteri, both mid-tolerant species, which included 81,000 seedlings and saplings < 5 cm per hectare and 560 ingrowth 5-10 cm trees per hectare. Conclusions: The irregular shelterwood cuts allowed the development of dense understorey tree layers below the residual trees. However, the tree composition of the new cohorts largely differed from that of the residual trees and was dominated by mid-tolerant species, including some short-lived species. The irregular shelterwood method proves appropriate for the EFT and may likely be successful in other forest types with valuable mid-tolerant species.
Copyright (c) 2024 Pablo J. Donoso, Tomás Riquelme-Buitano, Daniel P. Soto (Author) http://creativecommons.org/licenses/by/4.0
Indonesian timber harvesting workers’ knowledge of occupational safety and health
Background: Occupational accidents potentially occur in timber harvesting work. Because this work has a high accident risk, workers’ knowledge of occupational safety and health (OSH) is essential. In this study we analysed a group of Indonesian timber harvesting workers’ knowledge of OSH, particularly as it relates to operations in natural forests. Methods: We interviewed 30 people who directly undertake timber harvesting work and asked them to answer surveys containing 15 questions related to different aspects of OSH knowledge. Responses were quantified using the Likert scale and validity and reliability tests were performed. Results: The results showed that: 1) worker knowledge regarding the benefits of using personal protective equipment (PPE) was highest compared to the other 14 indicators; 2) workers had less knowledge about timber harvest planning, the meaning of occupational safety and health, safe ways of working and the frequency of work accidents when timber harvesting; and 3) validity and reliability tests showed that this survey was a valid instrument for collecting information on workers’ knowledge of OSH. Conclusions: The Indonesian timber harvesting workers surveyed had limited knowledge of the planning of tree felling, timber skidding, and loading, yet they perceive the cognition of OSH, working methods to minimise accidents, and the frequency of work accidents during timber harvesting every year. Ongoing training to improve workers’ knowledge of OSH, including correct use of personal protective equipment is important for reducing the risk of workplace accidents. The use of serious games can assist with this training.
Copyright (c) 2025 Yuniawati Yuniawati, Ane Dwi Septina, Mutia Herni Ningrum, Sarah Andini (Author) http://creativecommons.org/licenses/by/4.0
Forest and shrubland structure of Polylepis tarapacana in topographic and substrate gradients across the Argentine Altiplano
Background: Polylepis tarapacana (queñoa) is a species that grow from forests to shrublands in Chile, Argentina, Bolivia and Peru, reaching an elevation range of 4400-5000 m a.s.l. In Argentina, this species occurred in the Altoandina phyto-geographic eco-region, which presents scarce vegetation, and where it is the most important tree species for its great socio-economic importance. The structure of these communities and the changes related to environmental gradients are not well described in the literature. The objective was to relate topographic factors with variables of structure of the P. tarapacana communities, evaluating the occupation degree (e.g. density and crown cover) of the species. Methods: We studied P. tarapacana forests and shrublands in northern Argentina, sampling 98 plots (50–4000 m²) to measure diameter at the base (DAB-cm), dominant height (DH-cm), life forms, crown cover (CC-%), and density (DEN-n ha-1). Topographic variables (elevation, slope, aspect) and substrate type were also recorded. Generalized Linear Models (GLM) were used to assess the influence of topography on forest structure, and univariate analyses to evaluate structural changes across life forms with topography. Results: Great heterogeneity was observed in the structure of open forests or shrublands patches of P. tarapacana, at high elevations (<4500 m a.s.l.), gentle slopes (21°) and in north aspect (95% of the plots). Topographic factors influence vegetation structure variables, e.g: elevation has a significant positive effect on DH (β = 0.105, p = 0.011), while slope (β = -0.144, p = 0.001) and eastern aspect (β = -0.083, p = 0.040) have significant negative effects on DH (F=6.85, p <0.001). Slope was the only significant variable with a positive effect on CC (β = 0.275, p = 0.001). The life forms of P. tarapacana are influenced by topographic gradients, and the tallest communities (178.2 cm DH) are found at high elevations and low slopes, mainly in areas with bare soil and understorey vegetation. Conclusions: Polylepis tarapacana structure was associated to the studied topographic gradients. It is crucial to identify changes in the composition and structure of forest and shrubland, considering both the substrate in which they develop, and the different life forms they adopt.
Copyright (c) 2025 Victoria Lien López, Guillermo Martínez Pastur, Juan Manuel Cellini (Author) http://creativecommons.org/licenses/by/4.0
Wood density and stiffness of New Zealand native trees and shrubs
Background: New Zealand’s native forests are species-rich. Little information has been documented about the properties and historic uses of the lesser-utilised species. Xylaria, archives of wood samples, can be used to obtain information on timbers which are difficult to source. Methods: Wood density and stiffness of 115 native tree species archived in the New Zealand School of Forestry | Te Kura Ngahere’s xylarium were measured and put into context with available information from literature. Results: The range of wood density and stiffness of the New Zealand native tree species was comparable with that found globally, indicating a wide range of potential uses. Conclusions: Open access to wood properties of lesser-used New Zealand native tree species is essential to successfully implement New Zealand’s government policy of establishing a commercial native forestry sector. Wood density information can aid carbon accounting of native forests under the Emissions Trading Scheme.
Copyright (c) 2023 Georgia Kennedy, Meike Holzenkaempfer, Monika Sharma, Clemens Michael Altaner (Author) http://creativecommons.org/licenses/by/4.0