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In this work, we present a study about the application of bi-temporal, large interval aerial laser scans for constructing of tree growth models and estimating site index quality based on the measured increments from the laser scans. We compared two LiDAR scans with 14 years of difference in the national park area, where most areas are unmanaged. We derived the increment curve based on the Chapman-Richard growth formula. We used site index estimates from forest management plans from the national scale as the ground truth (both absolute and relative). We constructed three predictive models for site index estimates from bi-temporal scans, in modalities with and without stand age. Including the stand age improved all models, but even without the age, the models performed relatively well for differentiation between better and worse sites. At this moment, it is not directly possible to estimate age from remotely sensed data, but consistent monitoring, with laser scanning or photogrammetry, undoubtedly detects the harvest or dieback, so in the future, age can be considered as a variable easily estimated from remotely sensed data and so remote sensed material are viable source for understanding of forest growth and production. [ABSTRACT FROM AUTHOR]

Anthropogenic land use and land cover change (LULCC) is projected to continue in the future. However, the influence of forest management on forest productivity change and subsequent LULCC projections remains under‐investigated. This study explored the impacts of forest management‐induced change in forest productivity on LULCC throughout the 21st century. Specifically, we developed a framework to softly couple the Global Change Analysis Model and Global Timber Model to consider forest management‐induced forest productivity change and projected future LULCC across the five Shared Socioeconomic Pathways (SSPs). We found future increases in forest management intensity overall drive the increase of forest productivity. The forest management‐induced forest productivity change shows diverse responses across all SSPs, with a global increase from 2015 to 2100 ranging from 3.9% (SSP3) to 8.8% (SSP1). This further leads to an overall decrease in the total area with a change of land use types, with the largest decrease under SSP1 (−7.5%) and the smallest decrease under SSP3 (−0.7%) in 2100. Among land use types, considering forest management‐induced change significantly reduces the expansion of managed forest and also reduces the loss of natural land in 2100 across SSPs. This suggests that ignoring forest management‐induced forest productivity change underestimates the efficiency of wood production, overestimates the managed forest expansion required to meet the future demand, and consequently, potentially introduces uncertainties into relevant analyses, for example, carbon cycle and biodiversity. Thus, we advocate to better account for the impacts of forest management in future LULCC projections. Plain Language Summary: Land use and land cover change has shown widespread social, economic, and environmental impacts. However, the influence of forest management on forest productivity change and subsequent land use and land cover change projections remains under‐investigated. This study explored how changes in forest productivity caused by forest management practices impact land use and land cover throughout the 21st century under various social and economic scenarios. The results show that more intense forest management generally leads to more productive forests. This, in turn, results in smaller changes in land use and land cover. Increasing forest management reduces the need to expand managed forests and helps preserve natural lands by 2100. Ignoring the impact of forest management on forest productivity could lead to biases in projecting forest expansion and wood production and potentially induce uncertainties in carbon cycling and biodiversity. Our results emphasize the need to account for forest management in future projections of land use and land cover changes. Key Points: Forest management‐induced productivity change has a significant impact on future land use and land cover change (LULCC)Neglecting such impact could overestimate the managed forest expansion and natural land reduction, especially under SSP1 and SSP5We advocate considering such impacts during LULCC projection to constrain the uncertainty [ABSTRACT FROM AUTHOR]

Understanding needle biomass turnover rates in Scots pine (Pinus sylvestris L.) stands is crucial for modelling forest ecosystem dynamics and nutrient cycling. This study examined needle litterfall and biomass turnover in Scots pine stands of varying ages in temperate forests (western Poland). The research focused on determining how stand age affects needle biomass, litterfall and the associated turnover rates. Data were collected from 20 Scots pine stands aged 26 to 90 years, and needle litterfall was measured and analysed in relation to stand characteristics such as age, density and biomass. The average annual needle litter production of the sampled Scots pine stands was 2008 kg·ha−1·year−1, similar to the values previously reported for this tree species in other temperate forests in Europe. The average needle biomass turnover rate for sampled Scots pine stands was 23.4%. We could not support the hypothesis that this parameter depended on the age of the Scots pine stand. The needle biomass turnover rate showed a positive correlation with crown length and a negative correlation with stand density due to the very weak correlations; however, further research is needed to confirm these relationships. Despite this, the parameter can be used to estimate needle litterfall and can be applicable to conditions corresponding to those of temperate forests in Central and Western Europe. This study also highlights the need for further research on needle biomass turnover in temperate forests to improve the accuracy of carbon and nutrient cycling models. This work contributes to a deeper understanding of the role of needle litterfall in maintaining soil fertility and forest productivity, offering insights into sustainable forest management and conservation strategies. [ABSTRACT FROM AUTHOR]

Forest management changes the physical environments and nutrient dynamics and then regulates the forest productivity. Soil phosphorus (P) availability is critical for productivity in tropical and subtropical forests. However, it was still poorly understood howsoil P content and fraction respond to various forest management practices in these regions. Here, we measured the soil total P, available P, and Hedley's P fractions, including inorganic and organic P (Pi and Po), in subtropical pine plantations treated with understory removal (UR), non-dominant species thinning (NDST) and dominant species thinning (DST) after nine years. Compared to plantations without management (CK), treatments such as UR, NDST, and DST decreased soil total P at 0--10 cm and soil available P at 0-- 10 cm and 10--20 cm. Increases in resin-Pi, NaOH-Pi, and C.HCl-Pi resulted in a higher total Pi in 0--10 cm (p < 0.05) in treated plots (UR, NDST, and DST) than in CK plots. UR, NDST, and DST treatments increased NaHCO3-Po and NaOH-Po (p < 0.05) but decreased C.HCl-Po at a depth of 0--10 cm. Regardless of management treatments, soil total P, available P, and P fractions in 0--10 cm showed higher contents than those in 10--20 cm. There were positive relationships between total P and total Po (p < 0.01) and between available P and total Pi. There were also positive relationships between total P, available P, NaHCO3-Pi, and NaOH-Pi (p < 0.05). In conclusion, forest management such as UR, NDST, and DST decreased soil total P and available P, and transforming soil P fractions to available P will meet the P demand following management in the pine plantations of subtropical China. [ABSTRACT FROM AUTHOR]

Over the last decades, Chile has experienced a long-term drought with significant consequences for water availability, forest productivity, and soil degradation, ultimately dramatically increasing the surface of burned area. Here, we quantify the Palmer Drought Severity Index (PDSI) to ascertain the extent of "moisture deficiency" across the central-southern region of Chile from 2000 to 2023 to assess the drought's relationship with the frequency of wildfires focusing on the impact of native forests. Our methodology quantifies the PDSI from the burned area data using MODIS MCD64A1 satellite imagery, validated by in situ wildfire occurrence records. The findings indicate that 85.2% of fires occurred under moderate to severe drought conditions. We identified 407,561 ha showing varying degrees of degradation due to wildfires, highlighting the critical areas for targeted conservation efforts. A significant increase in both the frequency of wildfires and the extent of the affected area in native forests was observed with the intensification of drought conditions in the 21st century within mesic to humid Mediterranean climatic zones where drought explains up to 41% of the variability in the burned area (r2 = 0.41; p < 0.05). This study highlights the relationship between drought conditions and wildfire frequency, showing the paramount need to adopt comprehensive wildfire mitigation management in native forests. [ABSTRACT FROM AUTHOR]

Understanding the ecological dynamics of forest ecosystems, particularly the influence of forest age structure on soil carbon (C), nitrogen (N), and phosphorus (P) content, is crucial for effective forest management and conservation. This study aimed to investigate the nutrient storage and ecological stoichiometry across different-aged stands of Chinese fir forests. Soil samples were collected from various depths (0–15 cm, 15–30 cm, and 30–45 cm) across four age groups of Chinese fir forests (8-year-old, 12-year-old, 20-year-old, and 25-year-old) in the Forest Farm, Pingjiang County, China. Soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) were measured, and their stoichiometries were calculated. The results showed that both individual tree biomass and stand biomass, along with SOC, TN, and TP content, increased with stand age, highlighting the significant importance of stand age on biomass production and nutrient accumulation in forests. Specifically, soil C and P contents significantly increased as the forest aged, while variation in N content was relatively minor. Soil C/N and C/P ratios exhibited variation corresponding to forest age, suggesting alterations in the ecological stoichiometry characteristics of the forests over time. These findings are crucial for understanding the dynamics of ecosystem functioning and nutrient cycling within Chinese fir forests and provide a solid scientific basis for the effective management and conservation of these vital forest ecosystems. [ABSTRACT FROM AUTHOR]

The productivity of forests in sub-Saharan Africa is often summarized into large compartments or site classes. However, the classification of forest productivity levels based on the original site index model in Tanzania and the techniques applied to generate the model did not include the micro-toposequence variations within compartments. This may create false expectations of wood supply and hinder the estimation of sustainable harvesting processes. This study analyzed variations in forest productivity and the site index in P. patula stands in two forest plantations of Tanzania to assess the applicability and generality of the present site classification system. We used dominant height as a proxy for forest productivity in 48 plots at the Sao Hill forest plantation (SHFP) and 24 plots at the Shume forest plantation (SFP). We stratified the sampling plots in each site class along the soil catena and recorded the elevation, slope, and slope positions (summit, mid, and lower). Our results showed that the site classes did not generally match the previously assigned site classes and the productivity of a given site class varied between the two plantations. We found a consistently higher productivity than that implied by the original site index in SFP, while in SHFP, the productivity was both higher and lower than estimated in different compartments. Both elevations and slope significantly contributed to predicting the productivity variations within site classes. Overall, the results indicate that physiographic factors affect variations in forest productivity within the assigned site classes. We recommend a more comprehensive site productivity assessment that takes into account physiographic variations and hence provides more accurate information for sustainable forest plantation management in Tanzania and in the region at large. [ABSTRACT FROM AUTHOR]

Effective forest management strategies to adapt to climate change are essential. Water use efficiency (WUE), which integrates biomass production and water consumption, is a key indicator of forest adaptation. This study evaluated the WUE of Gmelina arborea plantations in the tropical dry forest and identified the main influencing factors, with implications for silviculture and management. Data on total biomass (TB) and total volume (V) were obtained from permanent sample plots in the upper and lower Magdalena River basin in Colombia. WUE was calculated as m3 of V (WUEV) or kg of TB (WUETB) per m3 of evapotranspired water. Significant regional differences were found, with higher WUE in the Caribbean plains (WUETB = 1 kg m−3 and WUEV = 0.0018 m3 m−3) compared to the inter-Andean valleys (WUETB = 0.77 kg m−3 and WUEV = 0.013 m3 m−3). Stand variables had the greatest influence on WUE, showing positive associations with site productivity and stand density measures. Soil variables such as texture, available water, and calcium content, along with a drier climate, were crucial for achieving higher WUE. The study underscores the importance of comprehensive site selection and effective silvicultural practices to maximize WUE and productivity, especially in the context of climate change. [ABSTRACT FROM AUTHOR]

[Objective] Forest health assessment is the basis for forest management. The aims of this study are to conduct forest health assessment, and to provide a certain theoretical basis for achieving sustainable forest management goals. [Methods] This study focused on the widely distributed plantations of Platycladus orientalis, Quercus variabilis, and Robinia pseudoacacia in the southern foothills of the Taihang Mountains. Principal component analysis, cluster analysis, and discriminant analysis were used. Stand productivity, site conditions, community organizational structure, stability and sustainability were selected to evaluate the forest health status, which composed of 21 secondary indicators. [Results Tree height, diameter at breast height, total soil K content and forest fire risk index were the main factors affecting forest health in the study area. Their principal component factor loadings were all greater than 0.6. Among the 17 surveyed plots, 8 plots had a forest health level of healthy' or 'sub healthy' (accounting for 47.0% of the total), while the corresponding forest health levels of Platycladus orientalis, Quercus variabilis, and Robinia pseudoacacia plantations were 60.0%, 33.4%, and 50.0%, respectively. The forest health levels of 9 plots were 'medium healthy' or 'unhealthy' (accounting for 53.0% of the total), and the corresponding forest health levels of Platycladus orientalis, Quercus variabilis, and Robinia pseudoacacia plantations were 40.0%, 66.7%, and 50.0%, respectively. Conclusion Overall, the health status of Platycladus orientalis and Robinia pseudoacacia plantations in the research area is good, while the health status of Quercus variabilis plantations is poor. [ABSTRACT FROM AUTHOR]

Texture, soil organic matter (SOM), and soil depth (SoD) are crucial properties in forest management because they can supply spatial information on forest site productivity and guide fertilizer applications. However, soil properties possess an inherent uncertainty that must be mapped to enhance decision making in management applications. Most digital soil mapping predictions primarily concentrate on the mean of the distribution, often neglecting the estimation of local uncertainty in soil properties. Additionally, there is a noticeable scarcity of practical soil examples to demonstrate the prediction uncertainty for the benefit of forest managers. In this study, following a digital soil mapping (DSM) approach, a Quantile Regression Forest (QRF) model was developed to generate high-resolution maps and their uncertainty regarding the texture, SoD, and SOM, which were expressed as standard deviation (Sd) values. The results showed that the SOM (R2 = 0.61, RMSE = 2.03% and with an average Sd = 50%), SoD (R2 = 0.74 and RMSE = 19.4 cm), clay (R2 = 0.63, RMSE = 10.5% and average Sd = 29%), silt (R2 = 0.59, RMSE = 6.26% and average Sd = 33%), and sand content (R2 = 0.55, RMSE = 9.49% and average Sd = 35%) were accurately estimated for forest plantations in central south Chile. A practical demonstration of precision fertilizer application, utilizing the predictive distribution of SOM, effectively showcased how uncertainty in soil attributes can be leveraged to benefit forest managers. This approach holds potential for optimizing resource allocation and maximizing economic benefits. [ABSTRACT FROM AUTHOR]

Riparian buffer zones (RBZs) are an important instrument for environmental policies for water and biodiversity protection in managed forests. We investigate the variation of the cost of implementing RBZs within different property size classes across the size range of non-industrial forest owner properties in Southern Sweden. Using the Heureka PlanWise decision support system, we quantified the cost of setting aside RBZs or applying alternative management in them, as the relative loss of harvest volume and of net present value per property. We did this for multiple simulated as well as real-world property distributions. The variation of cost distribution among small properties was 4.2–6.9 times higher than among large properties. The interproperty cost inequality decreased non-linearly with increasing property size and levelled off from around 200 ha. We conclude that RBZs, due to the irregular distribution of streams, cause highly unequal financial consequences for owners, with some small property owners bearing a disproportionally high cost. This adds to previous studies showing how environmental considerations differentially affect property owners. We recommend decision makers to stimulate the uptake of RBZs by alleviating these inequalities between forest owners by including appropriate cost sharing or compensation mechanisms in their design. [ABSTRACT FROM AUTHOR]

Visits to forests can improve human health and well-being through various mechanisms. They can support the immune system, promote physical activity, and restore stress and attention fatigue. Questions remain about how perceived qualities in forests important to support such salutogenic, i.e., health-promoting, benefits can be represented in forest simulation tools to allow quantitative analyses, e.g., long-term projections or trade-off analyses with other forest functions, such as biodiversity conservation, wood production, etc. Questions also remain about how different forest management regimes might impact such perceived qualities in forests. Here, we defined three types of salutogenic forest characteristics (SFCs), referred to as Deep, Spacious, and Mixed forest characteristics, respectively. We did so by using the perceived sensory dimension (PSD) model, which describes and interrelates more fundamental perceived qualities of recreational outdoor environments that are important to support people's health and well-being. We identified proxy variables for the selected PSD models in boreal forest stands and compared the effect of five different management regimes on both individual PSD models and the derived SFCs when projecting a forest landscape 100 years into the future. Our results suggest combinations of protection (set-aside) and variations of continuous cover forestry as the most promising strategies to achieve these salutogenic properties in the long-term future. Depending on the SFC in focus and the specific management regime used, between 20% and 50% of the landscape could support associated properties in the long term (100 years). This might impact how forests should be managed when salutogenic outcomes are considered alongside, e.g., wood production and other forest contributions. [ABSTRACT FROM AUTHOR]

Forest canopy structural complexity (CSC) plays a crucial role in shaping forest ecosystem productivity and stability, but the precise nature of their relationships remains controversial. Here, we mapped the global distribution of forest CSC and revealed the factors influencing its distribution using worldwide light detection and ranging data. We find that forest CSC predominantly demonstrates significant positive relationships with forest ecosystem productivity and stability globally, although substantial variations exist among forest ecoregions. The effects of forest CSC on productivity and stability are the balanced results of biodiversity and resource availability, providing valuable insights for comprehending forest ecosystem functions. Managed forests are found to have lower CSC but more potent enhancing effects of forest CSC on ecosystem productivity and stability than intact forests, highlighting the urgent need to integrate forest CSC into the development of forest management plans for effective climate change mitigation.. [ABSTRACT FROM AUTHOR]

In forests, the amount and diversity of structural features with high value for biodiversity, such as large trees and dead wood, are affected by productivity, stand age, and forest management. For efficient conservation of forest biodiversity, it is essential to understand the combined effects of these drivers. We used data from the Swedish National Forest Inventory to study the combined effects of productivity, stand age, and management for wood production on structures with high value for biodiversity: tree species richness, large living trees, dead wood volume, and specific dead wood types. Forest management changed the relationship between productivity and amount or diversity of some of the structures. Most structures increased with productivity and stand age, but decreased due to management. The negative effect of management was greatest for structures occurring mainly in high-productivity forests, such as deciduous dead wood. Thus, biodiversity conservation should target high-productivity forests to preserve these structures. [ABSTRACT FROM AUTHOR]

The aim of this study was aimed to estimate the economic value of timber products from the forest stands that are potentially saved from wildfires after improving road standards. The study was implemented in the Alanya Forest Enterprise Directorate (FED) in the Mediterranean city of Antalya, Turkey. In the solution process, the possible increase in the accessible forest areas with improved forest road standards was investigated by using GIS-based network analysis methods. In the next step, the timber production in the forest areas potentially saved from the wildfire was calculated based on parameters such as site index, rotation period, and stand structure. Then, the economic value of timber product types was calculated using market prices. The results indicated that increasing the design speed on improved forest roads reduced the arrival time of firefighting teams to the forests, which consequently increased the accessible forest areas within the critical response time. It was found that the accessible forest areas within the critical response time increased from 47,231 hectares to 59,354 hectares when standards of the forest roads were improved. This saved 12,123 hectares of additional forest area from the wildfire in the Alanya FED. The cost of road improvement activities was estimated at US$ 2,286,998. It was calculated that the total timber products obtained from the forest area potentially saved was about 94,721 m3, and worth US$7,545,579 at market prices. The results can be used by policymakers in determining the potential investments in improving forest road standards to enhance the efficiency of firefighting activities. [ABSTRACT FROM AUTHOR]

Stand spatial structure plays a key role in forest management, and in particular the random structural unit, comprising random tree and its neighbors, largely determines forest stability and its productivity. However, how the spatial structure of the random structural unit affects productivity remains unclear. The study focused on four larch forest types from Hebei and Shanxi provinces, China: 35‐year‐old larch (Larix principis‐rupprechtii) plantations (35LP), 39‐year‐old mixed larch–birch (Betula platyphylla) forests (39LB), 58‐year‐old natural larch forests (58LN), and 73‐year‐old mixed larch–birch–spruce (Picea asperata) forests (73LBS). The forest spatial structure index (FSSI) was employed to comprehensively evaluate the stand spatial structure. Additionally, the uniform angle index was used to discern whether the stand structure units were uniform, random, or clumped. A regression model was used to elucidate the effects of species mingling, diameter dominance, and crowding on the productivity of random trees. Results showed that the FSSI varied among the stand types, ranking as 35LP < 58LN < 39LB < 73LBS. The values of distribution frequency and the percentages of basal area increment (BAI) for random trees were above 0.5% and 40% in most stand types, respectively. The diameter dominance of random structural units in four stand types showed a significant negative correlation with the BAI of random trees, whereas the mingling and crowding of random structural units in the 73LBS displayed a significant positive correlation with BAI of random trees. Thus, increasing the size of random trees, as well as mingling and crowding in random structural units, can facilitate the formation of a rational stand spatial structure, thereby enhancing the productivity of larch forests. [ABSTRACT FROM AUTHOR]

Abstract Anthropogenic land use and land cover change (LULCC) is projected to continue in the future. However, the influence of forest management on forest productivity change and subsequent LULCC projections remains under‐investigated. This study explored the impacts of forest management‐induced change in forest productivity on LULCC throughout the 21st century. Specifically, we developed a framework to softly couple the Global Change Analysis Model and Global Timber Model to consider forest management‐induced forest productivity change and projected future LULCC across the five Shared Socioeconomic Pathways (SSPs). We found future increases in forest management intensity overall drive the increase of forest productivity. The forest management‐induced forest productivity change shows diverse responses across all SSPs, with a global increase from 2015 to 2100 ranging from 3.9% (SSP3) to 8.8% (SSP1). This further leads to an overall decrease in the total area with a change of land use types, with the largest decrease under SSP1 (−7.5%) and the smallest decrease under SSP3 (−0.7%) in 2100. Among land use types, considering forest management‐induced change significantly reduces the expansion of managed forest and also reduces the loss of natural land in 2100 across SSPs. This suggests that ignoring forest management‐induced forest productivity change underestimates the efficiency of wood production, overestimates the managed forest expansion required to meet the future demand, and consequently, potentially introduces uncertainties into relevant analyses, for example, carbon cycle and biodiversity. Thus, we advocate to better account for the impacts of forest management in future LULCC projections.

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Stand density affects the potentially superior productivity of forest ecosystems directly by regulating the light and nutrient availability of trees. Understanding how stand density influences the growth and development of trees is crucial for supporting forest management in the context of climate change. We focused on Liriodendron chinense in experimental plantations created in 2003, with planting densities ranging from 277 to 10,000 trees per hectare at six plots. The leaf structure and photosynthetic capacity of L. chinense changed significantly under different stand densities, which had a negative impact on their biomass (leaf mass) and nutrient (total carbohydrate content) accumulation. Transcriptional differences were observed among samples from plots with different planting densities. The expression of 1784 genes was negatively dependent on stand density, participating mainly in the biological processes of "circadian rhythm", "carbon metabolism", and "amino acid biosynthesis". Furthermore, we identified a photosynthesis-related module and constructed a gene regulatory network to discover that the transcription factors of MYB and bHLH may have important roles in the transcriptional regulation of photosynthesis biosynthesis by activating or repressing the expression of petA (Litul.15G096200), psbE (Litul.10G033900), and petD (Litul.17G061600) at different stand densities. Our study quantified the impact of stand density on tree growth at physiological and molecular levels. Our observations provide theoretical support for plantation establishment of L. chinense. [ABSTRACT FROM AUTHOR]

There is growing interest in continuous cover forestry in Sweden. The historical domination of even-aged forest management means there is a need to focus on methods for transforming even-aged to uneven-aged stands. Practical conversion management today is highly adaptive, and the possibility of failures, such as persistent lack of tree recruitment, must be allowed for. We used simulations to evaluate various scenarios in which conversion management is introduced at different development stages in even-aged stands and then abandoned in favour of clear-felling. A shift towards an inverse J-shaped diameter distribution at the end of the simulations was most evident in northern Sweden and with an early introduction of conversion forestry. The largest losses were incurred in a scenario where the conversion management started with removing larger trees at pre-commercial thinning: it reduced the volume of production by up to 25% and, if clear-felled, resulted in a lower land expectation value than conventional management. Earlier decision to abandon conversion management reduced the losses, but the effect of timing was minor. In summary, the results indicate that conversion management could be started and abandoned without any major economic loss during the timeframe of a normal rotation. [ABSTRACT FROM AUTHOR]

The long‐term effects of intensive forest harvest on sensitive demographic stages of the American black bear (Ursus americanus) have been often overlooked. Much of Maine, USA, is covered in forests that are hospitable to bears and commercial timber harvest. To investigate the potential effects of differing intensities of disturbance on black bears, and on females with cubs particularly, we designed a large‐scale natural experiment with 197 motion‐sensitive camera sites dispersed over representative forest stands in northern and central Maine. Using multi‐state occupancy models, we distinguished the overall trends in space use by females with young versus adult bears without young. Forest disturbance at large spatial scales was positively associated with the probability of use for both demographic groups and the availability of hardwood trees was an additional important factor for habitat use by females with young. Our study illustrates the use of motion‐sensitive cameras to monitor and understand habitat use by distinct life‐history stages of animals living in human‐modified landscapes, and results indicate that managers can maintain black bear habitat in areas of active forest harvest by ensuring the availability of hardwood species. [ABSTRACT FROM AUTHOR]

Selective logging in neotropical forests has directly affected the dynamics of tree species, compromising species conservation and timber yield. Sustainable use of logged forests requires new tree recruitment and diameter growth in remaining trees to compensate for trees removed between cutting cycles. This long-term study investigated timber yields in four species groups with differing values (lower, intermediate, high, and mixed) in logged and unlogged forests in the plateau region of the Tapajós River in the eastern Brazilian Amazon. Analysis was based on two size classes: medium and large commercial-sized trees. In both forest types (logged and unlogged), we found relevant tree recruitment and changes in size classes for all value groups. Most of the recruited trees observed during the 33 years of monitoring remained in the medium size class, but they also occurred in the large size class in logged forests. Over the same period, a significant loss of timber yield was seen, resulting from high mortality among the remaining trees in both size classes due to natural processes and the aftereffects of logging. Timber yield was also seen to be influenced by species richness within the group of commercial species, and recruitment and tree diameter growth capacity to counterbalance losses from mortality of the remaining trees after logging had become restricted. Forest timber yield was mainly regulated by light-demanding species, and shade-tolerant species contributed little to timber yield during the first cut. Continuous monitoring of the remaining trees and measures to reduce tree mortality during cutting cycles can encourage growth and reduce losses in stocked trees. Additionally, the national rules for forest management in the Brazilian Amazon need to be improved to achieve long-term management sustainability. [ABSTRACT FROM AUTHOR]

Forest canopy vertical layering influences stand development and yield and is critical information for forest management planning and wood supply analysis. It is also relevant for other applications including habitat modelling, forest fuels management and assessing forest resilience. Forest inventories that use coincident airborne Light Detection and Ranging (LiDAR) data and field plots (i.e. area-based approach) to predict forest attributes generally do not consider the multi-layer canopy structure that may be found in many natural and managed forest stands. With airborne LiDAR, it is possible to separate single-layer and multi-layer stands. This information can be used to allocate predictions of forest attributes such as timber volume (m3 ha−1), by canopy layer. In this study, we used single-photon LiDAR data to automate the mapping of vertical stand layering in a temperate mixedwood forest with a variety of forest types and vertical complexities. We first predicted whether each 25 × 25 m grid cell had one or two canopy layers, and then partitioned inventory attributes (e.g. basal area (BA), gross total stem volume (GTV)) by canopy layer. We compared two methods for estimating attributes by layer at the stand level using nine independent validation stands. Overall agreement between the reference and predicted structure for the calibration plots was 74% (n  = 266). At the grid-cell level, attributes were generally underestimated for the upper layer and overestimated for the lower layer. For the validation stands, the relative height of the lower layer was under-predicted compared to the reference data (46–52% versus 57%), while the proportion of BA and GTV in the lower layer were very similar to the reference values (17–19% versus 18% for BA and 12–15% versus 12% for GTV). Overall, the approach showed promise in distinguishing single- and two-layered stand conditions and partitioning estimates of inventory attributes such as BA and GTV by layer—both for grid cells and at the stand level. The inclusion of forest information by canopy layer enhances the utility of LiDAR-derived forest inventories for forest management in forest areas with complex, multi-layer stand conditions. [ABSTRACT FROM AUTHOR]

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The aim of this paper was to assess the influence of the silvicultural system (clear-cut and shelterwood), species composition of forest stands, in relation to the fluctuation of raw wood prices, on the economic results of forest management. Model analyses were performed on the example of the conditions of the CZU Forests, specifically for the third forest vegetation zone, SLT 3K. The input to the model evaluation was: data on the growth and production of the investigated tree species in the given site conditions from growth tables, the costs of forestry measures were derived from standards, the assortment was carried out on the basis of assortment tables, the prices of assortments of raw wood were taken from the data of the Czech Statistical Office for 2015 and 2019. The synthetic result of the model evaluations was the gross profit of forest production per hectare and year. The results of the analysis prove the economic advantage and greater stability of the shelterwood silvicultural system, especially with regard to lower silvicultural costs, higher volume of timber production and mutual compensation of the decrease and increase in the prices of raw wood of the evaluated tree species. [ABSTRACT FROM AUTHOR]

This study examines the efficiency of loblolly pine (Pinus taeda L.) production under roundwood and carbon price risks. The data are generated from the biophysical–economic optimization model, consisting of the loblolly pine growth and yield model in Georgia, United States, combined with a stochastic economic model. The model incorporates the timber and carbon price risk parameters and generates the optimal biomass volumes and the associated harvest profits for 56 scenarios given different silvicultural treatments and price risks. Timber production efficiencies under each scenario are evaluated using the data envelopment analysis. This study also assesses potential economic losses due to inefficient forest production. The result shows that forest landowners with lower risk tolerance have a higher profit foregone. Inefficient forest management could cause up to $319/ha and $405/ha of potential economic losses under herbicide and fertilizer treatment scenarios, respectively. As timber-related price risks can influence forest landowners' decisions, the findings of this study incorporating different risks would help forestry professionals and policymakers to establish a more realistic and greater degree of accuracy in the forest productivity evaluation. [ABSTRACT FROM AUTHOR]

Wood density (WD) is a key functional trait related to ecological strategies and ecosystem carbon dynamics. Despite its importance, there is a considerable lack of information on WD in tropical Andean forests, particularly regarding its relationship with forest succession and ecosystem carbon cycling. Here, we quantified WD in 86 upper Andean tree and shrub species in central Colombia, with the aim of determining how WD changes with forest succession and how it is related to productivity. We hypothesized that WD will increase with succession because early successional forests will be colonized by acquisitive species, which typically have low WD, while the shaded understory of older forests should favor higher WD. We measured WD in 481 individuals from 27 shrub and 59 tree species, and quantified aboveground biomass (AGB), canopy height, net primary production (NPP) and species composition and abundance in 14, 400-m², permanent plots. Mean WD was 0.513 ± 0.114 (g/cm³), with a range between 0.068 and 0.718 (g/cm³). Shrubs had, on average, higher WD (0.552 ± 0.095 g/cm³) than trees (0.488 ± 0.104 g/cm³). Community weighted mean WD (CWMwd) decreased with succession (measured as mean canopy height, AGB, and basal area); CWMwd also decreased with aboveground NPP and stem growth. In contrast, the percentage of NPP attributed to litter and the percent of shrubs in plots increased with CWMwd. Thus, our hypothesis was not supported because early successional forests had higher CWMwd than late successional forests. This was related to a high proportion of shrubs (with high WD) early in succession, which could be a consequence of: 1) a low seed availability of trees due to intense land use in the landscape and/or 2) harsh abiotic conditions early in succession that filter out trees. Forest with high CWMwd had a high %NPP attributed to litter because they were dominated by shrubs, which gain little biomass in their trunks. Our findings highlight the links between WD, succession and carbon cycling (biomass and productivity) in this biodiversity hotspot. Thus, WD is an important trait that can be used to understand upper Andean forest recovery and improve forest restoration and management practices. [ABSTRACT FROM AUTHOR]

Vegetation canopy height mapping is vital for forest monitoring. However, the high cost and inefficiency of manual tree measurements, coupled with the irregular and limited local-scale acquisition of airborne LiDAR data, continue to impede its widespread application. The increasing availability of high spatial resolution imagery is creating opportunities to characterize forest attributes at finer resolutions over large regions. In this study, we investigate the synergy of airborne lidar and high spatial resolution USDA-NAIP imagery for detailed canopy height mapping using an image-to-image deep learning approach. Our main inputs were 1 m NAIP image patches which served as predictor layers and corresponding 1 m canopy height models derived from airborne lidar data, which served as output layers. We adapted a U-Net model architecture for canopy height regression, training and validating the models with 10,000 256-by-256 pixel image patches. We evaluated three settings for the U-Net encoder depth and used both 1 m and 2 m datasets to assess their impact on model performance. Canopy height predictions from the fitted models were highly correlated (R2 = 0.70 to 0.89), precise (MAE = 1.37–2.21 m), and virtually unbiased (Bias = −0.20–0.07 m) with respect to validation data. The trained models also performed adequately well on the independent test data (R2 = 0.62–0.78, MAE = 3.06–4.1 m). Models with higher encoder depths (3,4) and trained with 2 m data provide better predictions than models with encoder depth 2 and trained on 1 m data. Inter-comparisons with existing canopy height products also showed our canopy height map provided better agreement with reference airborne lidar canopy height estimates. This study shows the potential of developing regional canopy height products using airborne lidar and NAIP imagery to support forest productivity and carbon modeling at spatially detailed scales. The 30 m canopy height map generated over Texas holds promise in advancing economic and sustainable forest management goals and enhancing decision-making in natural resource management across the state. [ABSTRACT FROM AUTHOR]

The spatial structure of forest stands significantly influences inter-tree competition and the overall stability of the stand's ecological dynamics, and a profound understanding of forest stand spatial structure is essential for both effective forest management and ecological research. Previous studies on spatial structure have primarily employed single variables, offering only one-dimensional structural insights and lacking the capacity to interpret multidimensional information. In light of these limitations, our study introduces a novel approach founded on a six-variable distribution, aimed at conducting a comprehensive analysis and interpretation of the spatial attributes of forest stands. Diverging from conventional univariate or bivariate methods, the hexi-variate approach simultaneously considers six variables, facilitating a more intricate exploration of the intricate interrelationships within forest ecosystems from six distinct dimensions. We conducted an in-depth analysis of the spatial structural attributes within the forest stand, encompassing factors such as species diversity, size variation, spatial distribution patterns, openness, vertical stratification, and stand competition. To capture a comprehensive view of the trees' spatial information, we employed the hexadecimal distribution method, effectively quantifying their characteristics across six dimensions. Our study unveiled a significant correlation between spatial structure and stand growth, establishing a connection by integrating the spatial structure with key structural features relevant to tree size. The outcomes of this study shed light on the effectiveness and superiority of the six-element distribution method when it comes to the analysis of forest structural characteristics. Our approach offers valuable insights into the optimization of forest management strategies, encompassing selective harvesting and biodiversity conservation, thereby establishing a solid footing for sustainable forest management practices. [ABSTRACT FROM AUTHOR]

Competition between the economic and natural assets of forests is emphasised in capercaillie lekking sites, which are often located within production forests. In this study, we assessed the potential use of carbon offsets as income for the management of capercaillie lekking sites. We ran simulations and optimisations for two alternative forest management scenarios in ten forest holdings located in five different regions of Finland. The size of each forest holding was approximately 30 hectares, of which 5 hectares was included in a lekking site. The basic scenario followed forest management recommendations, and the carbon sequestration scenario aimed to enhance biodiversity maintenance in a way that enabled carbon offsets to be obtained for the lekking site. We found that the decrease in revenue from timber sales was generally so small that the income from carbon offsets provided an economically better choice. Furthermore, the cost-effectiveness of carbon sequestration did not seem to be restricted to a specific location. The approach we introduced can be utilised in future decision making in the forestry sector to promote the coordination of nature management and forestry. Moreover, carbon pools should be considered more comprehensively in future research. [ABSTRACT FROM AUTHOR]

Accurate forest information on tree species, stand age, tree density, and stand volume is required to ensure effective forest management practices. In Japan, forest information is consolidated in forest yield tables and stand density management diagrams (SDMDs) that are specifically designed for major forest plantation species. In this study, we analyzed whether the current full density curve in the SDMD of Hinoki (Chamaecyparis obtusa) plantation stands in Kyushu Island aligns with the characteristics of the existing stands. Data from 18 Hinoki forests were used to measure tree heights, diameters, and densities. Equations were developed to establish relationships between stand factors, and various curves were derived for average height, competition ratio, full density, yield ratio, average diameter, and natural mortality. The results showed that the current full density curve in the SDMD for Hinoki plantation stands did not completely align with the characteristics of the existing Hinoki plantation stands in Kyushu Island. Thus, the full density curve in the SDMD for the Hinoki stands in this region should be significantly adjusted. These results can enhance forest management in Japan and advance SDMD modeling and its application in forest planning and management. [ABSTRACT FROM AUTHOR]

Measuring tree growth rates is an important requirement in many scientific disciplines and forest production sector. The assessment of annual volume growth rates in standing living trees, under ambient field conditions without destroying the tree has so far only been conducted with model approaches or by repeated measurements of tree dimensions in the field. This research note proposes a novel simple non-destructive method for the estimation of annual volume increment in standing trees, based on tree ring analysis of sampling of the two increment cores for each targeted tree and simple trigonometry rules. The extracted data by the method application can be widely used in many forest disciplines, such as forest ecology, silviculture, and forest management. [ABSTRACT FROM AUTHOR]

There is increasing interest in optimizing stand structure through forest management. The forest structure influences growth and maintains the structure, promoting sustainability. Structure-based forest management (SBFM), which is based on the spatial relationships between a reference tree and its four nearest neighbors, considers the best spatial structure for the stand and promotes the development towards a healthy and stable state by selectively thinning specific trees. This management method is a scientific approach for sustainable forest management, and appropriate harvesting is the core principle of uneven-aged forest management. However, the application of this approach in the management of uneven-aged mixed stands is a challenge because their dynamics are more difficult to elucidate than those of planted or pure stands. This study presented a stand spatial structure optimization model with a transition matrix growth model for selecting suitable timber harvest during uneven-aged mixed-forest management optimization. The model was developed using three neighborhood-based structural indices (species mingling, diametric differentiation, and horizontal spatial pattern) and diameter diversity indices. The approach was applied to four broadleaf stands in the Maoershan Forest Farm of the Heilongjiang Province. The results demonstrate that optimizing the stand spatial structure with a transition matrix growth model improved the objective function values (F-index) by 23.8%, 12.8%, 14.6%, and 28.3%, and the optimal removal of trees from the stands ranged from 24.3% to 25.5%. The stand structure in the next cycle (after 5 years) was closer to the uneven-mixed state. The main conclusion of this study is that optimizing the stand spatial structure with a transition matrix growth model can improve the speed and accuracy of tree selection for harvesting in unevenly mixed forests, thus helping regulate stable and diverse forest growth. [ABSTRACT FROM AUTHOR]

An improved understanding of biodiversity-productivity relationships (BPRs) along environmental gradients is crucial for effective ecosystem management and biodiversity conservation. The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions. However, there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes. To study how BPRs change with elevation, we harnessed inventory data on 6,431 trees from 152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia. We quantified the relationship between aboveground productivity and different biodiversity measures, including taxonomic, functional, and phylogenetic diversity. To elucidate the processes underlying BPRs, we studied the variation of different functional traits along elevation across landscapes. We found no general pattern of BPRs across landscapes and elevations. Relationships were neutral for all biodiversity measures in temperate forests, and negative for taxonomic and functional diversity in subtropical forests. BPRs were largely congruent between taxonomic, functional and phylogenetic diversity. We found only weak support for the stress-gradient hypothesis, with BPRs turning from negative to positive (effect not significant) close to the tree line in subtropical forests. In temperate forests, however, elevation patterns were strongly modulated by species identity effects as influenced by specific traits. The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes. Our study highlights the context-dependence of BPRs across elevation gradients and landscapes. Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity. Furthermore, our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist, which require more attention in policy and management.

There is limited research about the interacting impacts of hurricane damage and forest disturbances like invasive species and wildfires on nonindustrial forest land management. We administered a mail survey to 1,000 randomly selected nonindustrial private forest landowners in the Panhandle of Florida who owned forestlands in the counties most severely affected by Hurricane Michael. Results show that most landowners did little to no forest management to prepare for the hurricane. Following Hurricane Michael, 34% of respondents reported increased invasive plants whereas 82% experienced timber loss, 62% had damaged wildlife habitats, and 53% had increased vulnerability to wildfire hazards. Landowners who experienced timber damage from Hurricane Michael were more likely to reduce fire hazard, eliminate or reduce invasive plants, perform road and trail maintenance, improve wildlife habitat, reforest both salvage harvested and areas that were not salvage harvested, search for information on the internet about forest management, and pass their forestland to family. Study Implications: Forest disturbances such as hurricanes, invasive species, and wildfires are predicted to increase in severity and frequency, consequently affecting forest productivity, sustainability, and management. Despite significant impacts on forest lands, there is limited understanding of how these disturbances may affect nonindustrial private forest landowner management behaviors. This article highlights the attitudes, experiences, and perceptions of nonindustrial private forest landowners, including their awareness and overall forest management plans regarding invasive species control, wildlife habitat improvement, and reducing wildfire hazards after a hurricane. We assessed the important factors that contribute to landowners' willingness to take action to address these interacting forest disturbances. [ABSTRACT FROM AUTHOR]

The article presents the results of the research on the features of Pinus sylvestris L. condition and productivity in forest stands of the Left-Bank Forest-Steppe of Ukraine (in Kharkiv and Sumy regions) for 2006–2021. The study was carried out using the 'Forests of Ukraine' Database as of 01.01.2017, and the results of field research at 30 temporary sample plots (TSP), 3 permanent sample plots (PSP) (in 2006–2018), and 13 monitoring plots (2009–2021). Generally accepted methods and new standards were used. The dynamics of forestry and evaluation indicators of Scots pine stands at sample plots were analyzed and compared with high-productive Scots pine stands. The characteristics of natural regeneration are given. It was revealed that the age structure of pine stands is not optimal: there is an excess of middle-aged stand areas. Changes in the structure and development of managed Scots pine stands with respect to changing environmental conditions were observed for 2009–2021. Studied forest stands showed a tendency for negative changes in stand structural characteristics related to regeneration and growth. Drought mainly in combination with even medium anthropogenic impact can further worsen the health status of Scots pine stands in lowland areas of the Left-Bank Forest-Steppe of Ukraine. Thus, the formulation of forest management measures to mitigate the impact of these stress factors is needed. [ABSTRACT FROM AUTHOR]

Digitalization is the process of utilizing digital technologies and digitized data to enable or improve forest operations. Digitalization lowers expenses while increasing productivity and efficiency and the existing forestry processes and operations are improved by digitalization. There is little or no knowledge about the use of modern technology in Nigeria which has led to low level or optimum effective and efficient utilization of forest products in a sustainable developmental way. Therefore, there is a need for technology transfer and research development in forestry industry management in Nigeria. Forestry in Nigeria is still majorly managed by the government in view to cater for the welfare of the society rather than the profitability of the forest industry and few private forestry plantations. The adoption and implementation of digitalization in the forestry industry in Nigeria will revolutionize and cause a significant, positive shi&, and increase the forest management and productivity of forest operations, which will further improve the forest yields on sustainable basis. [ABSTRACT FROM AUTHOR]

Key message: We found that the stabilizing mechanisms for forest productivity varied across harvesting intensities in a mixed broad-leaved Korean pine forest. Effects of overyielding at high species richness and species asynchrony occurred only in unharvested and lightly harvested plots, whereas asymmetries between individuals of different size contributed significantly to stabilizing productivity when harvestings became intensive. Context: Understanding the driving factors of forest ecosystem stability has become increasingly crucial in forest management. However, it remains unclear whether and how the stabilizing mechanisms of forest productivity might be influenced by management practices. Aims: We related the temporal stability of aboveground biomass productivity to harvesting history. We further tested how three key driving mechanisms of stability might be modulated by selective harvesting intensities. Methods: Based on a 10-year monitoring (five repeated tree inventories) of a mixed broad-leaved Korean pine forest in Northeastern China recovering from selective harvesting, we examined the relative importance of two diversity-dependent mechanisms (overyielding and species asynchrony) and one size-dependent mechanism (asymmetric growth) for productivity stability across a wide range of intensities (0–73.4% basal area removed). Results: We found that selective harvesting significantly lowered the productivity stability, species asynchrony, and growth dominance coefficient. Growth dominance coefficient had an overall stronger effect on stability than species richness and asynchrony. Moreover, the strengths of stabilizing mechanisms varied across harvesting intensities: effects of overyielding at high species richness and species asynchrony were detected only in unharvested and lightly harvested plots, whereas the explanatory power of growth dominance coefficient outweighed the diversity-related variables when harvesting became intensive. Conclusions: We emphasized the importance to consider both diversity- and size-related explanatory variables as potential mechanisms for the temporal stability of forest productivity. In fact, how growth is partitioned among trees of different species as well as sizes may co-determine the response of forest stability to disturbances. [ABSTRACT FROM AUTHOR]

The link between biodiversity and ecosystem function can depend on environmental conditions. This contingency can impede our ability to predict how biodiversity‐ecosystem function (BEF) relationships will respond to future environmental change, causing a clear need to explore the processes underlying shifts in BEF relationships across large spatial scales and broad environmental gradients. We compiled a dataset on five functional traits (maximum height, wood density, specific leaf area [SLA], seed size, and xylem vulnerability to embolism [P50]), covering 78%–90% of the tree species in the National Forest Inventory from Italy, to test (i) how a water limitation gradient shapes the functional composition and diversity of forests, (ii) how functional composition and diversity of trees relate to forest annual increment via mass ratio and complementarity effects, and (iii) how the relationship between functional diversity and annual increment varies between Mediterranean and temperate climate regions. Functional composition varied with water limitation; tree communities tended to have more conservative traits in sites with higher levels of water limitation. The response of functional diversity differed among traits and climatic regions but among temperate forest plots, we found a consistent increase of functional diversity with water limitation. Tree diversity was positively associated with annual increment of Italian forests through a combination of mass ratio and niche complementarity effects, but the relative importance of these effects depended on the trait and range of climate considered. Specifically, niche complementarity effects were more strongly associated with annual increment in the Mediterranean compared to temperate forests. Synthesis: Overall, our results suggest that biodiversity mediates forest annual increment under water‐limited conditions by promoting beneficial interactions between species and complementarity in resource use. Our work highlights the importance of conserving functional diversity for future forest management to maintain forest annual increment under the expected increase in intensity and frequency of drought. [ABSTRACT FROM AUTHOR]

Managed low‐severity surface fires are frequently implemented in efforts to restore disturbance processes to forests of North America; although the effects of managed fire on forest structure are well‐studied, few studies investigate whether these disturbances cascade to impact pollinator communities.We analysed bee‐habitat relationships in fire‐treated (1‐ and 3‐years post‐treatment) and non‐treated ponderosa pine stands in Colorado to test wild bee population responses.Observed bee richness and α‐diversity were highest in stands 1‐year post‐fire and had more Anthophora, Bombus, Osmia and Lasioglossum spp. in comparison to 3‐year post‐fire and non‐treated stands. Bee functional groups were responsive to treatments, with more below‐ground nesting taxa present in stands 3 years post‐fire.Floral richness was the highest mid‐growing season (June, July) and within 1‐year post‐fire stands.A model analysing the effects of foraging and nesting habitat variation on bee assemblages indicated positive association between floral richness and bee α‐diversity, but negative relationships with stand basal area. Nesting habitat was not associated with variation in bee assemblages.We conclude that managed fire has positive short‐term effects on bee biodiversity that are likely mediated by floral richness. However, these effects were not detectable by 3 years post‐treatment in the southern Rocky Mountain region. [ABSTRACT FROM AUTHOR]

Context: Planted pine forests are highly abundant communities in the Mediterranean Basin. Being the result of past reforestation, these forests show high species and structural homogeneity. Diversification to conifer-broadleaved mixed forests is recommended to promote adaptation to climate change and increase their resilience to perturbations. Objectives: This study aims at evaluating how these planted pine forests will develop in the future as a result of the combined impacts of management and climate. Methods: We applied a forest landscape model (LANDIS-II) to simulate different climate scenarios and management strategies designed in cooperation with forest managers to assess their effects on the performance of planted pine forests and their change in terms of forest composition. Results: Climate change scenarios caused a shift in the phenological growth pattern of planted pine forests by reducing forest growth during summer and increasing photosynthetic productivity in spring and fall, particularly under high emission scenarios. Biomass increased through time and more strongly under climate change, but this increase differs among species, resulting in changes of forest types across the landscape. Our results portray natural succession as the main driver of forest change, but intensive management accelerated this process by limiting pine growth and promoting growth of oak species. Conclusions: Our results highlight the importance of active management on planted pine forests to favour mixed and climate-adapted ecosystems in shorter time scales than offered by succession alone. Moreover, our spatially explicit modelling approach helps to identify areas where lack of seed dispersal and/or competitive exclusion prevent natural diversification, providing useful recommendations for interventions. However, the modelling approach has some limitations since it does not consider natural disturbances. [ABSTRACT FROM AUTHOR]

Forest productivity is a key driver of forest growth and yield and a critical information need for forest management and planning. Traditionally, this information has come from field plots, but these are expensive to measure and have limited coverage. Remote sensing, on the other hand, can provide forest inventory attributes on landscape scales and with a relatively low cost. A common predictor of forest productivity is site index (SI), traditionally estimated from age and height. In plantations, age can often be treated as a known quantity, but in natural-origin forests (of which Canada has vast swaths), age is often unknown and must be estimated, requiring expensive field work and resulting in a high level of error which, in turn, introduces error into SI estimates. The objective of this study is to generate estimates of SI from two successive LiDAR captures. The 99th percentiles (p99) of LiDAR returns from two successive captures 13 years apart were used along with species-specific SI curves to estimate SI. The results were compared to field-based estimates of SI for two major boreal species, jack pine and black spruce in managed and unmanaged conditions. Overall, the difference between the LiDAR-based SI and the field estimate was 2% with a relative mean squared error of 18%. For the few situations in which the height change was small or negative (less than 0.5%/year), SI was estimated from the average p99 and an assumed age of 100. The advantage of this method is that it does not require field sampling or estimates of age. Using two successive LiDAR captures, wall to wall estimates of SI can be generated at the grid cell level (e.g., 20 × 20 m), a level of detail generally not found in inventories. Overall, our results demonstrate the excellent potential for estimating SI from LiDAR alone, without age, to provide detailed productivity information for forest management and inventory that has been lacking in most large-scale inventories until now. [ABSTRACT FROM AUTHOR]

Measurement of the recovery of wood stocks in logging areas in the Amazon helps to understand the efficiency of policies for the use and conservation of native forests. This work evaluated the effects of logging on the dynamics and production of commercial species in the short and medium term in a conservation unit in the state of Rondônia. Structural patterns of the species as a function of mortality and recruitment rates, patterns of average increment in diameter, and estimates of forest production in the short and medium term were analyzed. The study was carried out in an area designated as Annual Production Unit 2 of Forest Management Unit III of Jamari National Forest. In addition to legalized harvesting, there are reports of illegal logging in the area as of 2015. Inventory data from 2011, 2015, and 2018 were used, considering trees of commercial value with a diameter at breast height (DBH) greater than 10 cm. Mortality rate, recruitment, periodic annual increment, absolute tree density, basal area, and commercial volume, by species and DBH classes, as well as the similarity of the species regarding the growth pattern. The population structure of species over the years was affected by tree mortality, mainly due to damage caused by illegal logging. Mean increment values varied by species and diameter classes, and six species represented 72% of the total volume of wood stock. It is important to review the criteria for sustainable forest production in the long term. Thus, it is necessary to promote species diversity and improve public authorities' capacity to enforce and of the private sector to comply with legislation. This, in turn, will enable the development of strategies to make the consumption of legal wood more rational. [ABSTRACT FROM AUTHOR]

It is not clear if mature secondary growth coniferous forests can support similar pollinator communities as old growth coniferous forests, or how active management (e.g., retention forestry) in mature secondary growth forests may affect pollinator communities. We compare the native bee community and plant‐bee interaction networks of old growth, naturally regenerating and actively managed (retention forestry) mature secondary growth forests of similar stand age. Old growth forests had a higher bee species richness and Shannon's diversity index, but not Simpson's diversity index, than both actively managed and naturally regenerating mature secondary forests. Forest type (old‐growth, naturally regenerating mature secondary growth, and actively managed mature secondary growth) had a significant effect on bee community composition. Redwood forest bee‐plant interaction networks were small in size and had lower complexity than expected and few connector species. While studies suggest that small‐scale timber harvest may increase bee biodiversity in the short‐term in other coniferous forest habitats, our study suggests that there may be long‐term negative effects of clear‐cutting that lower bee biodiversity in mature secondary growth forests as compared to mature old‐growth forests. [ABSTRACT FROM AUTHOR]

Investigating how the productivity dynamics of planted forests vary over time is important for understanding the resilience of forests against disturbance and for maximizing ecological restoration and replanting efforts. In this study, the patterns of interannual variability in net primary production (NPP) were analyzed for planted forests as indicated by the inverse of the coefficient of variation (ICV) time series at a ten-year moving window on the Loess Plateau, China, from 2000 to 2021. The spatial–temporal patterns were defined based on the increase or decrease trend obtained using the ordinary least squares method between abrupt change points performed by a Mann–Kendall test in an ICV time series, as follows: only one linear trend, increase (LI), and decrease (LD); at least two trends, increase firstly and decrease lastly (ID) and decrease firstly and increase lastly (DI); and other trends. The results showed that 82.74% of the ICV on the Loess Plateau displayed LD and ID patterns, indicating an increasing variability of forest productivity in this region. Overall, 73.83% of the ICV had a lower degree of rate decrease in the last phase than during the initial increase. Thus, the variability was in an early stage of increasing degree. The ICV time series showed an LI pattern in the eastern Gansu and the southern Shanxi, indicating a decreased variability, due partly to the improved forest restoration. When the plantation age was considered, the newly planted forests (less than 19 a) exhibited a decreasing variability, indicating the proactive role of forest management and restoration in averting environmental disruptions in dry environments. [ABSTRACT FROM AUTHOR]

According to protection targets of EU Biodiversity Strategy 2030, 30% of EU's land and sea area should be legally protected by 2030. While the actual targets and even terms are still to be defined, the strategy's possible impacts can be simulated for policy support purposes. The strategy aims to increase protection by setting aside forests and extending closer-to-nature forest management practices. We simulated Finland's forest resources with the European Forestry Dynamics Model (EFDM) considering the protection targets. According to our simulations, the total growing stock and net present value will be lower with the additional protection than by carrying on the business-as-usual management. The additional protection resulted in intensified harvesting in the remaining forest area available for wood supply with the current harvest level. This may weaken the positive ecological impacts of protection. Reducing the harvest level from the current level is not a likely alternative either, because the demand for biomass is predicted to increase in the future, while the supply is insufficient, and EU policies aim to avoid shifting the negative impacts of resource extraction outside the EU. The feasibility of the additional protection depends on the actual implementation and definitions. [ABSTRACT FROM AUTHOR]

Forest management and planning efforts often account for many resource objectives and benefits, including wildlife habitat. In particular, newly approved management goals and harvest targets on state lands in Minnesota were examined for their potential impact on wildlife habitat. Using a list of stands planned for potential harvest and a regional wildlife habitat model, habitat effects were assessed for 173 native, forest-dependent wildlife species on state lands. Leveraging forest type– and region-specific harvest probabilities and post-examination lag times to harvest, three simulation efforts covering the spectrum of possible outcomes were used to estimate habitat change from 2020 to 2030. In the most realistic simulation, 31.8% of species exhibited statistically significant positive habitat change, 11.6% significant negative change, and 56.6% nonsignificant or no change. Compared with simulations reflecting more extreme levels of harvest, the realistic simulation showed the greatest compromise between negative and positive shifts in habitat. Results reflect tradeoffs in wildlife habitat preferences such that changes in management that positively affect certain species often negatively affect others. Tradeoffs may be addressed by providing flexibility to individual managers where a targeted prescription is justified for a specific species, all while continuing broad statewide forest management goals. [ABSTRACT FROM AUTHOR]

Climate change is posing new challenges to forestry management practices. Thinning reduces competitive pressure in the forest by repeatedly reducing the tree density of forest stands, thereby increasing the productivity of plantations. Considering the impact of thinning on vegetation and physiological and ecological traits, for this study, we used Norway spruce (Picea abies) data from three sites in the PROFOUND dataset to parameterize the 3-PG model in stages. The calibrated 3-PG model was used to simulate the stand diameter at breast height and the stem, root, and leaf biomass data on a monthly scale. The 3PG-MT-LSTM model uses 3-PG simulation data as the input variable. The model uses a long short-term memory neural network (LSTM) as a shared layer and introduces multi-task learning (MTL). Based on the compatibility rules, the interpretability of the model was further improved. The models were trained using single-site and multi-site data, respectively, and multiple indicators were used to evaluate the model accuracy and generalization ability. Our preliminary results show that, compared with the process model and LSTM algorithm without MTL and compatibility rules, the hybrid model has higher biomass simulation accuracy and shows a more realistic biomass response to environmental driving factors. To illustrate the potential applicability of the model, we applied light (10%), moderate (20%), and heavy thinning (30%) at intervals of 10, 15, 20, 25, 30 years. Then, we used three climate scenarios—SSP1-2.6, SSP2-4.5, and SSP5-8.5—to simulate the growth of Norway spruce. The hybrid model can effectively capture the impact of climate change and artificial management on stand growth. In terms of climate, temperature and solar radiation are the most important factors affecting forest growth, and under warm conditions, the positive significance of forest management is more obvious. In terms of forest management practices, less frequent light-to-moderate thinning can contribute more to the increase in forest carbon sink potential; high-intensity thinning can support large-diameter timber production. In summary, moderate thinning should be carried out every 10 years in the young-aged forest stage. It is also advisable to perform light thinning procedures after the forest has progressed into a middle-aged forest stage. This allows for a better trade-off of the growth relationship between stand yield and diameter at breast height (DBH). The physical constraint-based hybrid modeling approach is a practical and effective tool. It can be used to measure long-term dynamic changes in forest production and then guide management activities such as thinning to achieve sustainable forest management. [ABSTRACT FROM AUTHOR]