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.

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.

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.

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.

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.

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.

Background: Weed control has been one of the most significant factors in forest establishment practices that can improve biomass production, and herbicides represent the most effective and convenient way to control weeds. The environmental concern about herbicides in this industry is because the herbicide-treated area is often located near water reservoirs or areas where rivers and creeks originate. This study aimed to determine the adsorption and degradation behaviours of seven ionic herbicides used in forestry production in five Chilean forestry soils and their relation to the leaching and to generate information to validate environmental predictive models. Methods: Adsorption and degradation of ionisable herbicides such as simazine, terbuthylazine, hexazinone, metsulfuron-methyl, indaziflam, flazasulfuron and glyphosate were studied in Andisol, Ultisol, Inceptisol, Entisol and Alfisol forestry soils, to be related to their leaching in 100-cm high and 11-cm diameter soil disturbed lysimeters. Herbicides were quantified using high-pressure liquid chromatography and gas chromatography. Relationships between soil physicochemical properties, herbicide adsorption and degradation, and herbicide leaching were determined. Results: In decreasing order, the herbicides were mobile in Entisol>Alfisol>Ultisol>Inceptisol>Andisol soils. On the other hand, the more leachable herbicides, from high to low, were: hexazinone, metsulfuron-methyl, simazine, glyphosate, terbuthylazine, flazasulfuron and indaziflam. The last two herbicides were not detected below 60 cm soil depth. In general, the maximum soil depth herbicide reached and the percentage mass leached up to 90 cm soil depth were inversely related to soil adsorption (1/Kd), soil porosity, humidity, silt, aluminium, and calcium soil content. Herbicide degradations were generally faster than referential published values. Conclusions: The environmental coefficients of ionic herbicides were more related to soil properties than their physicochemical properties. Persistence of herbicides in soil was smaller than that commonly reported in other studies or international databases and soil adsorption averages were generally higher than international reference values. The stronger relationship between ionic herbicide behaviour and forestry soil properties endorses the requirement to determine the environmental herbicides parameters in situ, avoiding using parameters estimated in other soils.

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.