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Forest productivity is a crucial integrator of ecosystem functions and services. Although the effects of landscape structure on species richness and stand structure have been extensively studied, how landscape structures affect forest productivity and their interactions with stand‐level attributes, especially in the context of considerable land use change, remain unclear. In this study, we investigated the effects of landscape structures (fragmentation, complexity, and heterogeneity) and their interactions with stand‐level attributes on forest productivity in the conterminous United States across three spatial scales (1–3 km), using an extensive forest inventory dataset from the national forest inventories (NFI) plots. Our results revealed that all landscape indices around selected forest plots significantly increased from 2006 to 2016. Across three scales, forest productivity and stand‐level attributes (number of trees, tree species richness, and structural diversity) exhibited unimodal relationships with landscape fragmentation and complexity, while generally showed positive correlations with landscape heterogeneity. The interactions between landscape structures and stand attributes enhanced the explanatory power of forest productivity. Landscape complexity directly or indirectly reduced forest productivity by decreasing the number of trees and tree species richness, whereas landscape fragmentation and heterogeneity had the opposite effects. Furthermore, landscape heterogeneity and stand age had relatively stronger total effects (the sum of direct and indirect effects) on forest productivity, and their strength increased modestly with spatial scales. However, tree species richness consistently had the lowest total effects. Our study elucidates the complex driving mechanisms of landscape patterns on forest productivity across spatial scales, providing a deeper understanding of ecosystem complexity and responses to accelerating land use changes. [ABSTRACT FROM AUTHOR]

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]

By introducing the local density factor into the taper equation, five Larix olgensis plantations in Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province, were scanned by TLS. The tree height, diameter at breast height and diameter at different relative heights of Larix olgensis were extracted from the collected point cloud data. Based on Kozak variable exponential taper equation, a taper equation with local density factor was constructed, and the fitting result was R²adj=0. 935, RMSE=0. 735 6, Bias=0. 869 3. The research showed that: the taper equation model with local density factor had good fitting accuracy, Compared with the traditional Kozak taper equation model and the taper equation model with global density factor, the taper equation model with local density factor had better fitting effect. The calculation range of the local density factor of the Larix olgensis taper equation was positively correlated with tree height and diameter at breast height. The experimental results can provide a theoretical basis for scientific and reasonable timber production in Mengjiagang Forest Farm, and preliminarily reveal the influence of local density factor on the trunk shape of Larix olgensis. [ABSTRACT FROM AUTHOR]

Salinity is an abiotic factor limiting plant fitness and therefore forest crop productivity, and salt-affected areas have been expanding throughout the world. Ectomycorrhizal (ECM) fungi can improve the salt tolerance of woody plants, including Eucalyptus species To screen for salt-resistant Pisolithus albus (PA) isolates, 16 PA isolates were cultivated on modified Melin-Norkrans agar containing NaCl at concentrations of 0, 10, 20, and 30 dS m−1. The P. albus isolate PA33 had the greatest salt resistance under 10 and 20 dS m−1 NaCl, which are soil salinity levels in salt-affected areas of Thailand. We studied the effect of PA33 on Eucalyptus camaldulensis × E. pellita cuttings under salt stress (0 and 16 dS m−1) for 1 month. PA enhanced the growth of the Eucalyptus seedlings, as indicated by higher relative growth rates in height and root collar diameter of inoculated seedlings compared with non-inoculated seedlings. Moreover, the inoculated seedlings had less cell damage from NaCl, as indicated by significantly lesser leaf thickness and electrolyte leakage than the controls. These findings could lead to practices conferring socioeconomic and environmental benefits, as abandoned salt-affected areas could be reclaimed using such Eucalyptus seedlings inoculated with salt-tolerant ECM fungi. [ABSTRACT FROM AUTHOR]

Among the set of phenological traits featuring mangrove ecosystems, litterfall production stands out with marked intra-annual and longer-term variation. Furthermore, mangrove forests resilience is one of the most important ecological attribute, reconciling the juxtaposed terrestrial and marine environment such transitional systems occupy. However, world's mangroves are nowadays facing recurrent climatic events, reflected in anomalies depicted by major drivers, including temperature and precipitation. This physical-environmental setting may either constrain or favor overall forest productivity. A combination of time series analysis (spectral density and cross-correlation techniques) and statistical model fitting (General additive model) was implemented to explore trends in total litterfall of a well-developed mangrove forest in southeastern Gulf of Mexico (Celestun Lagoon, SE Mexico) and potential association with the varying behavior of temperature (°C) and precipitation (mm month-1), highlighting their anomalies. The results are consistent with a synchronous response between litterfall production and climatic variables (mean monthly temperature and total monthly precipitation). Concurrent peak litterfall production in Celestun lagoon with high temperatures and precipitation occurred during June and October, featuring a two-month time lag for the response time. More than half of the litterfall anomalies (53.5%) could be reflecting either multiple sources of climatic anomalies (maximum, minimum, and monthly average temperature and monthly total precipitation) or single point events (cyclone landfall). This relationship dynamics showed an interannual persistence (1999–2010). The structure portrayed by the litterfall time-series was not unequivocally related to climatic anomalies. Arguably, climatic anomalies behave with different intensities and even may exhibit complex interactions among them. The study of anomalies provides a baseline for a better grasp of: i) mangrove anomalies responses and ii) their vulnerability to these extremes. [ABSTRACT FROM AUTHOR]

Understanding mechanisms stabilizing ecosystem functions, such as primary production, is crucial for forecasting global environmental responses. While biological diversity is expected to enhance stability through compensatory reactions to environmental changes, empirical evidence is lacking, especially in old‐growth forests vital for biodiversity conservation and climate change mitigation. Moreover, whether increased niche complementarity and stronger intraspecific than interspecific competition are key mechanisms promoting compensatory dynamics and stabilizing ecosystem functions in diverse forests remains unexplored. This study investigates productivity and stability in temperate old‐growth forests over 20 years at community and individual levels. Analysing 4380 trees in a 4‐ha plot in northern Japan with over 35 tree species, structural equation models evaluated the effects of biodiversity and average asynchrony in species fluctuations (compensatory dynamics) on productivity stability across 100 m2 grid quadrats. Functional traits and taxonomic diversity represented species complementarity and the insurance effect. Temporal growth correlations between conspecific and heterospecific neighbours and neighbourhood effects on growth performance indicated intra‐ and interspecific interactions at the individual level. Communities with greater stability exhibited higher diversity and asynchronous species fluctuations, suggesting that compensatory dynamics buffer community productivity against environmental variability. The inverse relationship between tree size variation and stability indicates that communities with less pronounced size and abundance hierarchies have more efficient compensatory mechanisms, ensuring stable forest functioning. The absence of negative temporal correlations in biomass production among heterospecific neighbours suggests the limited significance of interspecific competition in compensatory dynamics. Conversely, positive correlations among conspecific neighbours and their suppressed growth in dense conspecific patches highlight the importance of conspecific negative density‐dependent mechanisms in sustaining tree species diversity and ensuring stable productivity. Synthesis: The study underscores the critical role of tree species richness in stabilizing ecosystem functioning via asynchronous growth in one of the world's most diverse temperate forests. Stronger intraspecific than interspecific competition helps prevent single‐species dominance, maintaining diversity and productivity stability. Despite occasional destabilization from size‐asymmetric interspecific competition, species‐trait complementarity enhances stability by promoting overall biomass production. This study highlights the importance of overall diversity for the stability of forest productivity, with implications for nature conservation and ecosystem functionality. [ABSTRACT FROM AUTHOR]

Extending and safeguarding tropical forest ecosystems is critical for combating climate change and biodiversity loss. One of its constituents, lianas, is spreading and increasing in abundance on a global scale. This is particularly concerning as lianas negatively impact forests' carbon fluxes, dynamics, and overall resilience, potentially exacerbating both crises. While possibly linked to climate-change-induced atmospheric CO2 elevation and drought intensification, the reasons behind their increasing abundance remain elusive. Prior research shows distinct physiological differences between lianas and trees, but it is unclear whether these differences confer a demographic advantage to lianas with climate change. Guided by extensive datasets collected in Panamanian tropical forests, we developed a tractable model integrating physiology, demography, and epidemiology. Our findings suggest that CO2 fertilization, a climate change factor promoting forest productivity, gives lianas a demographic advantage. Conversely, factors such as extreme drought generally cause a decrease in liana prevalence. Such a decline in liana prevalence is expected from a physiological point of view because lianas have drought-sensitive traits. However, our analysis underscores the importance of not exclusively relying on physiological processes, as interactions with demographic mechanisms (i.e., the forest structure) can contrast these expectations, causing an increase in lianas with drought. Similarly, our results emphasize that identical physiological responses between lianas and trees still lead to liana increase. Even if lianas exhibit collinear but weaker responses in their performance compared to trees, a temporary liana prevalence increase might manifest driven by the faster response time of lianas imposed by their distinct life-history strategies than trees. [ABSTRACT FROM AUTHOR]

Slot structure is the equilibrium result of market demand side and slot resource supply side, while slot parameters reflect the operational support capacity of the aviation system. Time parameters reflect the operational support capability of the aviation system. Time structure should not only reflect changes in market demand, but also meet the constraints of operational efficiency. Constructing a reasonable 18–24 h timetable profile for busy airports that meets normal expectations for declared capacity and seasonal scheduling is a challenge in civil aviation slot management. This study utilizes historical data on airport flights and weather conditions to establish a regression prediction model for the time structure using K-means clustering and partial least squares regression. Additionally, ensemble learning is employed to forecast flight delay levels. The findings demonstrate that random forest yields favorable results in regression and prediction tasks, allowing for the integration of upper (good weather) and lower (severse weather) limits of the time profile with delay predictions as time parameter intervals. Consequently, the flights falling within these intervals achieve an average delay level of less than 15 min which meets the expectations of normal flight. [ABSTRACT FROM AUTHOR]

Neonatal medical data holds critical information within the healthcare industry, and it is important to analyze this data effectively. Machine learning algorithms offer powerful tools for extracting meaningful insights from the medical data of neonates and improving treatment processes. Knowing the length of hospital stay in advance is very important for managing hospital resources, healthcare personnel, and costs. Thus, this study aims to estimate the length of stay for infants treated in the Neonatal Intensive Care Unit (NICU) using machine learning algorithms. Our study conducted a two-class prediction for long and short-term lengths of stay utilizing a unique dataset. Adopting a hybrid approach called Classifier Fusion-LoS, the study involved two stages. In the initial stage, various classifiers were employed including classical models such as Logistic Regression, ExtraTrees, Random Forest, KNN, Support Vector Classifier, as well as ensemble models like AdaBoost, GradientBoosting, XGBoost, and CatBoost. Random Forest yielded the highest validation accuracy at 0.94. In the subsequent stage, the Voting Classifier—an ensemble method—was applied, resulting in accuracy increasing to 0.96. Our method outperformed existing studies in terms of accuracy, including both neonatal-specific length of stay prediction studies and other general length of stay prediction research. While the length of stay estimation offers insights into the potential suitability of the incubators in the NICUs, which are not universally available in every city, for patient admission, it plays a pivotal role in delineating the treatment protocols of patients. Additionally, the research provides crucial information to the hospital management for planning such as beds, equipment, personnel, and costs. [ABSTRACT FROM AUTHOR]

On 12 sample plots established in the ecotone of the northern forest boundary in the Khadyta-Yakha River valley on the Yamal Peninsula, time of emergence and death, as well as productivity of about 1000 Siberian larch (Larix sibirica Ledeb.) and Siberian spruce (Picea obovata Ledeb.) trees were analyzed. Over the last 140 years, there has been a sharp increase in the stocks and annual growth of stem phytomass of woody plants within the studied ecotone. Since the 1970s, the average annual growth of phytomass has been increased by 1.2–39 times, which was facilitated by a 0.9°C increase in average June–July air temperature. However, this effect is insignificant in areas of mixed open forests subjected to periodic logging. [ABSTRACT FROM AUTHOR]

Quantifying nitrogen uptake rates across different forest types is critical for a range of ecological questions, including the parameterization of global climate change models. However, few measurements of forest nitrogen uptake rates are available due to the intensive labor required to collect in situ data. Here, we seek to optimize data collection efforts by identifying measurements that must be made in situ and those that can be omitted or approximated from databases. We estimated nitrogen uptake rates in 18 mature monodominant forest stands comprising 13 species of diverse taxonomy at the Morton Arboretum in Lisle, IL, USA. We measured all nitrogen concentrations, foliage allocation, and fine root biomass in situ. We estimated wood biomass increments by in situ stem diameter and stem core measurements combined with allometric equations. We estimated fine root turnover rates from database values. We analyzed similar published data from monodominant forest FACE sites. At least in monodominant forests, accurate estimates of forest nitrogen uptake rates appear to require in situ measurements of fine root productivity and are appreciably better paired with in situ measurements of foliage productivity. Generally, wood productivity and tissue nitrogen concentrations may be taken from trait databases at higher taxonomic levels. Careful sorting of foliage or fine roots to species is time consuming but has little effect on estimates of nitrogen uptake rate. By directing research efforts to critical in situ measurements only, future studies can maximize research effort to identify the drivers of varied nitrogen uptake patterns across gradients. [ABSTRACT FROM AUTHOR]

Summary: Decades of studies have demonstrated links between biodiversity and ecosystem functioning, yet the generality of the relationships and the underlying mechanisms remain unclear, especially for forest ecosystems.Using 11 tree‐diversity experiments, we tested tree species richness–community productivity relationships and the role of arbuscular (AM) or ectomycorrhizal (ECM) fungal‐associated tree species in these relationships.Tree species richness had a positive effect on community productivity across experiments, modified by the diversity of tree mycorrhizal associations. In communities with both AM and ECM trees, species richness showed positive effects on community productivity, which could have resulted from complementarity between AM and ECM trees. Moreover, both AM and ECM trees were more productive in mixed communities with both AM and ECM trees than in communities assembled by their own mycorrhizal type of trees. In communities containing only ECM trees, species richness had a significant positive effect on productivity, whereas species richness did not show any significant effects on productivity in communities containing only AM trees.Our study provides novel explanations for variations in diversity–productivity relationships by suggesting that tree–mycorrhiza interactions can shape productivity in mixed‐species forest ecosystems. [ABSTRACT FROM AUTHOR]

Tree functional diversity can increase forest productivity by enhancing species interactions and providing greater growth stability. However, very few studies have examined the influence of tree community trait structure on survivor growth, recruitment and mortality simultaneously, which are the main drivers of forest population dynamics.Here, we explore the interactions among functional diversity, productivity and climate to investigate the role of the trait structure of communities on forest productivity and to determine under what circumstances functional diversity should be promoted to ensure forest adaptive capacity under future climate.Using random‐forest modelling and a network of permanent sample plots covering a broad gradient of climatic conditions, we isolated the effects of functional diversity—described as the distribution of trait values in a community—and climate variables on net forest productivity (NFP), survivor growth, recruitment and mortality.Based on our findings, community‐level trait structure affects forest productivity in different ways. NFP was influenced by three traits from three different plant strategy dimensions, whereas survivor growth and recruitment were strongly correlated with leaf and resource acquisition traits, and tree mortality with a mix of traits reflecting various plant strategies.We also observed climate interactions with the functional trait structure of tree communities. For instance, we observed an interaction between drought tolerance and mean annual temperature: At low temperatures, NFP biomass accumulation increased with the value of the drought tolerance trait; however, at higher temperatures, the opposite pattern was observed. However, we found contrasting patterns of population response to climate variability, depending on their functional diversity. Greater functional diversity does not necessarily increase biomass accumulation under different climatic conditions.Synthesis. As all components of forest productivity contribute to NFP, studies on forest productivity should consider not only survivor growth but also recruitment and mortality. Each component responds differently in terms of biomass changes in climatic variation, according to the trait structure of tree communities. This study provides a framework to identify the trait structure that should be targeted under different climate scenarios to anticipate change and help strengthen forest response capacity to climate change. [ABSTRACT FROM AUTHOR]

Populus tomentosa, an indigenous tree species, is widely distributed and cultivated over 1,000,000 km2 in China, contributing significantly to forest production, ecological conservation and urban–rural greening. Although a reference genome is available for P. tomentosa, the intricate interspecific hybrid origins, chromosome structural variations (SVs) and sex determination mechanisms remain confusion and unclear due to its broad and even overlapping geographical distribution, extensive morphological variations and cross infiltration among white poplar species. We conducted a haplotype‐resolved de novo assembly of P. tomentosa elite individual GM107, which comprises subgenomes a and b with a total genome size of 714.9 Mb. We then analysed the formation of hybrid species and the phylogenetic evolution and sex differentiation across the entire genus. Phylogenomic analyses suggested that GM107 likely originated from a hybridisation event between P. alba (♀) and P. davidiana (♂) approximately 3.8 Mya. A total of 1551 chromosome SVs were identified between the two subgenomes. More noteworthily, a distinctive inversion structure spanning 2.15–2.95 Mb was unveiled among Populus, Tacamahaca, Turaga, Aigeiros poplar species and Salix, highlighting a unique evolutionary feature. Intriguingly, a novel sex genotype of the ZY type, which represents a crossover between XY and ZW systems, was identified and confirmed through both natural and artificial hybrids populations. These novel insights offer significant theoretical value for the study of the species' evolutionary origins and serve as a valuable resource for ecological genetics and forest biotechnology. [ABSTRACT FROM AUTHOR]

The current study assessed the association of eucalyptus-tree spacing with forest growth and yield, as well as with the floristic composition, diversity and yield of natural grassland grown in silvopastoral systems in Pampa biome. Data were collected in six family cattle-ranching area in Bagé County (RS). The effect of two different genetic materials (seminal-origin Eucalyptus dunnii plant and one Eucalyptus grandis clone) on shading features of plants grown in 3 planting-spacing dimensions (625, 312 and 208 trees ha-1) was assessed, as well as their association with herbaceous extract (bare soil; green cover; forage dry matter; floristic composition; species richness; and grass, legumes and winter - and summer-growth species rates) and forestry (litter accumulation, diameter at breast height, total height and volume per hectare) variables. Planting carried out at the highest tree density (625 trees ha-1) has increased forest yield. However, it reduced green cover, herbaceous extract dry-matter yield and species richness, mainly in grasses and legumes with greater forage potential. Conversely, it is possible combining forestry and animal yield to the preservation of native forage species at low tree densities (204 to 312 trees ha-1). [ABSTRACT FROM AUTHOR]

The recovery of soil properties and the proper growth of natural tree regeneration are key elements for maintaining forest productivity after selective logging operations. This study was conducted on the soil properties and natural growth of two pioneer seedling species of alder and maple which were on skid trails in the mixed beech forests of northern Iran. To examine the long-term effects, we randomly selected six skid trails, with two replicates established for each of three time periods since last use (10, 20, and 30 years ago). Random plots 4 m × 10 m in size, three plots on each skid trail and six plots on areas without soil compaction (control), were selected. Measurements included the physical and chemical properties of the soil and the growth, and the architectural and qualitative characteristics of the seedlings. The results showed that all the soil properties of the 10- and 20-year-old skid trails were significantly different from the control area (except for the soil moisture in the 20-year-old skid trail). The 30-year-old skid trail showed values of other soil properties which were not significantly different from the control area, except for the amounts of organic matter and soil nitrogen, which was less than the control. The skid trails had a negative effect on all of the growth, qualitative, and architectural indices of seedlings. The characteristics of seedlings were related to soil characteristics and had the highest correlation with the soil penetration resistance (R-value from −0.41 to −0.63 for stem growth, p < 0.05; −0.57 to −0.90 for root growth, p < 0.01; and −0.76 to −0.86 for biomass, p < 0.01). The correlation coefficient between soil penetration resistance and the Dickson quality index of alder and maple seedlings was, respectively, −0.74 and −0.72, p < 0.01. The negative effect of soil compaction on root growth (−27.69% for alder seedlings and −28.08% for maple seedlings) was greater than on stem growth (−24.11% for alder seedlings and −16.27% for maple seedlings). The amount of growth, qualitative, and architectural indices of alder seedlings were higher than that of maple seedlings. Although alder is a better choice as compared to maple seedling in the initial year, the results of our study show that it is recommended to plant both alder and maple on skid trails after logging operations. [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]

Reclamation of disturbances from oil sands mining requires effective soil management to ensure successful plant establishment and to promote recovery of native plant communities. In this study we investigated the effects of salvage depths (shallow vs. deep) and placement depths (shallow vs. deep) of forest topsoil on plant establishment, species richness, and soil properties in two substrate types (sand and peat-mineral). Shallow salvage led to greater tree stem densities and higher canopy cover for most plant groups, although there was no significant difference in species richness between shallow and deep salvages. Deep placement generally resulted in greater canopy cover, while its effect on plant density was very small for most plant groups. On peat-mineral substrate, fewer differences were detected between shallow and deep salvage, and multiple treatments resulted in greater cover. Findings suggest that a balance between maximizing the area over which propagules are redistributed and providing sufficient resources for successful plant establishment is necessary. Forest topsoil from shallow salvages and deep placements is recommended when targeting increased site productivity and species diversity. In contrast, deep salvage should be used when the primary objective is to obtain maximum reclamation material volume. Salvage depth effects may be influenced by substrate type, with peat-mineral substrate providing more favourable conditions for plant establishment. Further research is needed to assess the long-term impacts of different salvage and placement depths on plant community development and the potential effects of substrate properties on soil and plant response. [ABSTRACT FROM AUTHOR]

Fertilizer input is one of the effective forest management practices, which improves soil nutrients and microbial community compositions and promotes forest productivity. However, few studies have explored the response of rhizosphere soil microbial communities to various fertilization regimes across seasonal dynamics. Here, we collected the rhizosphere soil samples from Phoebe bournei plantations to investigate the response of community assemblages and microbial interactions of the soil microbiome to the short-term application of four typical fertilizer practices (including chemical fertilizer (CF), organic fertilizer (OF), compound microbial fertilizer (CMF), and no fertilizer control (CK)). The amendments of organic fertilizer and compound microbial fertilizer altered the composition of rhizosphere soil bacterial and fungal communities, respectively. The fertilization regime significantly affected bacterial diversity rather than fungal diversity, and rhizosphere fungi responded more sensitively than bacteria to season. Fertilization-induced fungal networks were more complex than bacterial networks. Stochastic processes governed both rhizosphere soil bacterial and fungal communities, and drift and dispersal limitation dominated soil fungal and bacterial communities, respectively. Collectively, these findings demonstrate contrasting responses to community assemblages and interactions of rhizosphere bacteria and fungi to fertilizer practices. The application of organic fertilization strengthens microbial interactions and changes the succession of key taxa in the rhizosphere habitat. Key points: • Fertilization altered the key taxa and microbial interaction • Organic fertilizer facilitated the turnover of rhizosphere microbial communities • Stochasticity governed soil fungal and bacterial community assembly [ABSTRACT FROM AUTHOR]

Understanding the biodiversity–productivity relationship (BPR) is crucial for biodiversity conservation and ecosystem management. While it is known that diversity enhances forest productivity, the underlying mechanisms at the local neighborhood level remain poorly understood. We established a 9.6 ha dynamic forest plot to study how neighborhood diversity, intraspecific competition, and interspecific competition influence tree growth across spatial scales using linear mixed-effects models. Our analysis reveals a significant positive correlation between neighborhood species richness (NSR) and relative growth rate (RGR). Notably, intraspecific competition, measured by conspecific neighborhood density and resource competition, negatively impacts RGR at finer scales, indicating intense competition among conspecifics for limited resources. In contrast, interspecific competition, measured by heterospecific density and resource competition, has a negligible impact on RGR. The relative importance of diversity and intra/interspecific competition in influencing tree growth varies with scale. At fine scales, intraspecific competition dominates negatively, while at larger scales, the positive effect of NSR on RGR increases, contributing to a positive BPR. These findings highlight the intricate interplay between local interactions and spatial scale in modulating tree growth, emphasizing the importance of considering biotic interactions and spatial variability in studying BPR. [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]

A long-standing key issue for examining the relationships between biodiversity and ecosystem functioning (BEF), such as forest productivity, is whether ecosystem functions are influenced by the total number of species or the properties of a few key species. Compared with controlled ecosystem experiments, the BEF relationships in secondary forest remain unclear, as do the effects of common species richness and rare species richness on the variation in ecosystem functions. To address this issue, we conducted field surveys at five sampling sites (1 ha each) with subtropical secondary evergreen broad-leaved forest vegetation. We found (1) a positive correlation between species richness and standing aboveground biomass (AGB); (2) that common species were primarily responsible for the distribution patterns of species abundance and dominance; although they accounted for approximately 25% of the total species richness on average, they represented 86–91% of species abundance and 88–97% of species dominance; and (3) that common species richness could explain much more of the variation in AGB than total species richness (common species plus rare species) at both the site and plot scales. Because rare species and common species were not equivalent in their ability to predict productivity in the biodiversity-ecosystem productivity model, redundant information should be eliminated to obtain more accurate results. Our study suggested that woody plant species richness and productivity relationship in subtropical forest ecosystem can be explained and predicted by a few common species. [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]

Tasmanian eucalypt forests are among the most carbon‐dense in the world, but projected climate change could destabilize this critical carbon sink. While the impact of abiotic factors on forest ecosystem carbon dynamics have received considerable attention, biotic factors such as the input of animal scat are less understood. Tasmanian devils (Sarcophilus harrisii)—an osteophageous scavenger that can ingest and solubilize nutrients locked in bone material—may subsidize plant and microbial productivity by concentrating bioavailable nutrients (e.g., nitrogen and phosphorus) in scat latrines. However, dramatic declines in devil population densities, driven by the spread of a transmissible cancer, may have underappreciated consequences for soil organic carbon (SOC) storage and forest productivity by altering nutrient cycling. Here, we fuse experimental data and modeling to quantify and predict future changes to forest productivity and SOC under various climate and scat‐quality futures. We find that devil scat significantly increases concentrations of nitrogen, ammonium, phosphorus, and phosphate in the soil and shifts soil microbial communities toward those dominated by r‐selected (e.g., fast‐growing) phyla. Further, under expected increases in temperature and changes in precipitation, devil scat inputs are projected to increase above‐ and below‐ground net primary productivity and microbial biomass carbon through 2100. In contrast, when devil scat is replaced by lower‐quality scat (e.g., from non‐osteophageous scavengers and herbivores), forest carbon pools are likely to increase more slowly, or in some cases, decline. Together, our results suggest often overlooked biotic factors will interact with climate change to drive current and future carbon pool dynamics in Tasmanian forests. [ABSTRACT FROM AUTHOR]

There is considerable interest in identifying and locating natural forests as accurately as possible, because they are deemed essential in preventing biodiversity loss. In the boreal region, natural forests contain a substantial amount of dead wood and exhibit considerable variation in tree age, size, and species composition. However, it is difficult to define natural forests in a quantitative manner. This is an issue, for example, in the Finnish national forest inventory. If naturalness could be related to the metrics derived from tree measurements, it would be easier to locate natural forests based on the inventory data. In this study, we investigated the value of metrics computed from tree locations and tree sizes for the characterization of a key aspect of naturalness, namely, structural naturalness as defined in the Finnish national forest inventory. We used L-moments, Gini coefficient, Lorenz asymmetry, and interquartile range to quantify the variations in tree size at the plot level. We summarized the spatial pattern of trees with a spatial aggregation index. We compared the structural metrics, species proportions, and stand age using the classes of structural naturalness described in the Finnish national forest inventory, which have been determined in the field without strict numerical rules. These categories are 'natural', 'near-natural', and 'non-natural'. We found that the forests evaluated as structurally natural had larger variations in tree size and species composition and showed a more clustered spatial pattern of trees on average, although the variation in the structural metrics was considerable in all three classes. In addition, we used the structural metrics to predict naturalness by employing a random forest algorithm. Based on the structural metrics, it was possible to obtain high precision in the classification only if we simultaneously accepted low recall, and vice versa; the link between the inspected metrics and naturalness evaluated in the field was weak. The stand age separated the three classes more clearly and it also improved the classification. [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]

Tidal freshwater forests are usually located at or above the level of mean high water. Some Louisiana coastal forests are below mean high water, especially bald cypress (Taxodium distichum (L.) Rich.) forests because flooding has increased due to the combined effects of global sea level rise and local subsidence. In addition, constructed channels from the coast inland act as conduits for saltwater. As a result, saltwater intrusion affects the productivity of Louisiana's coastal bald cypress forests. To study the long-term effects of hydrology and salinity on the health of these systems, we fitted dendrometer bands on selected trees to record basal area increment as a measure of growth in permanent forest productivity plots established within six bald cypress stands. Three stands were in freshwater sites with low salinity rooting zone groundwater (0.1–1.3 ppt), while the other three had higher salinity rooting zone groundwater (0.2–4.9 ppt). Water level was logged continuously, and salinity was measured monthly to quarterly on the surface and in groundwater wells. Higher groundwater salinity levels were related to decreased bald cypress radial growth, while higher freshwater flooding increased radial growth. With these data, coastal managers can model rates of bald cypress forest change as a function of salinity and flooding. [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]

Recent studies on the intra-annual dynamics of trees were mainly focused on mature trees in natural forests; however, less is known about how topography (e.g., slope's position and aspect) shape the intra-annual xylem formation dynamics of young trees in plantation forests. We monitored intra-annual xylem formation dynamics of 6-year-old Chinese fir (Cunninghamia lanceolata (Lamb.)) trees across two different aspects (northeast and southwest) and three different positions (upper, middle, and lower) of the slope in a planted forest in subtropical China. We found that the intra-annual xylem formation of trees on the northeast slope aspect (176.98 ± 34.52 cells) was significantly higher than that on the southwest slope aspect (140.19 ± 36.07 cells) due to the higher growth rate (0.67 ± 0.11 cells/day vs. 0.53 ± 0.10 cells/day). In the middle slope position, xylem formation (187.89 ± 19.81 cells) was also significantly higher than that of the upper (147.35 ± 29.08 cells) and lower slope positions (140.51 ± 48.36 cells), resulting from higher growth rate rather than longer growing season length. Our study demonstrated that intra-annual xylem formation dynamics of Chinese fir were altered by different topographic features and therefore encourage the implementation of management strategies that consider different slope aspects and positions to maximize forest productivity. [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]

Fusarium circinatum, the causative agent of pine pitch canker disease, is a pathogenic fungus that poses a significant threat to pine forests globally. It infects various Pinus species, causing resinous cankers, needle discoloration, and tree death. The disease severely impacts forest ecosystems, necessitating cost-effective and environmentally friendly management strategies. Contaminated pine seeds and seedlings are the main pathways for introducing this fungus to disease-free areas. To mitigate this disease and prevent its spread, it is crucial to implement new processes in forest plant production systems that align with the existing conditions of forest nurseries, ensuring effective and sustainable management. With this in mind, a national collaborative study involving 14 Portuguese partners was initiated to develop new prevention and mitigation strategies. In this work, four different treatments—MennoFlorades, Captan, ethanol, and hot water—were tested for their ability to eliminate F. circinatum from contaminated Pinus seeds in vitro. The most effective treatments were selected for further in vitro assays and real-context nursery germination trials to assess their impacts on seed germination, plant production, and certification. MennoFlorades, Captan, and hot water were tested in the nursery, with hot water showing the most promising results due to its negligible impact on seedlings, eco-friendly nature, ease of implementation, and cost-effectiveness. These findings offer promising prospects for preventing pine pitch canker outbreaks in nurseries and, consequently, in forests. [ABSTRACT FROM AUTHOR]

The stand basal area, closely related to age, site quality, and stand density, is an important factor for predicting forest growth and yield. The accurate estimation of site quality is especially a key component in the stand basal area model. We utilized sample plots with Picea asperata Mast. as the dominant species in the multi-period National Forest Inventory (NFI) dataset to establish a site index (SI) model including climate effects through the difference form of theoretical growth equations and mixed-effects models. We combined the SI calculated from the SI model, stand age, and stand density index to construct a basal area growth model for Picea asperata Mast. stands. The results show that the Korf model is the best SI base model for Picea asperata Mast. The mean temperatures in summer and winter precipitation were used as the fixed parameters to construct a nonlinear model. Ultimately, elevation, origin, and region, as random effects, were incorporated into the mixed-effects model. The coefficients (R2) of determination of the base model, the nonlinear model including climate, and the nonlinear mixed-effects model are 0.869, 0.899, and 0.921, with root-mean-square errors (RMSEs) of 1.320, 1.315, and 1.301, respectively. Among the basal area models, the Richards model has higher precision. And the basal area model including an SI incorporating climatic factors had a higher determination coefficient (R2) of 0.918 than that of the model including an SI without considering climatic effects. The mixed-effects model incorporating climatic and topographic factors shows a better fitting performance of SI, resulting in a higher precision of the basal area model. This indicates that in the development of forest growth models, both biophysical and climatic factors should be comprehensively considered. [ABSTRACT FROM AUTHOR]

We measured light‐related patterns of primary productivity within a topographically complex Oregon watershed over a 30‐year period. Second‐growth conifer densities were experimentally altered in 1981. Plots receiving at least 3434 MJ m−2 over a 6‐month growing season averaged 40% greater aboveground net primary productivity (ANPP) than those receiving less light (p = 0.000). Unthinned stands potentially built enough LAI to compensate for low light, but risked mortality that exceeded resilience. The two light levels acted as basins of attraction for other physiological and ecological processes, including size–density relationships and limiting foliar nutrients. Initial (1981) LAI and the irradiation step (above or below 3434 MJ m−2) explained 60% of variation in a 30‐year ANPP. Irradiation within each light group did not affect ANPP. At high irradiation, foliar N/Ca and slope steepness (both negative) explained 58% of the variation in residuals from the initial models, while at low irradiation on north, east, and west aspects, 83% of residual variation was explained by foliar Mg (+), understory cover (+), and 30‐year mortality (−). Light use efficiency (LUE) of fully stocked stands correlated with LAI and foliar N/K. Results suggest that understory influence on tree foliar N (+ or −) enhances ANPP by regulating critical nutrient ratios. Mortality reduced or eliminated differences among thinning levels, which did not vary at low light and only between unthinned and heavily thinned at high light. Values associated with relatively open forests (biodiversity, resilience) may be attained without large sacrifice of long‐term carbon sinks. In our study, light interacts with topography to produce nonlinear dynamics in which small changes in irradiation can have large consequences. Reduced sunlight has been suggested as a geoengineering option to combat global warming. Ecological changes out of proportion to lowered irradiation are a distinct possibility, including sharp reductions in terrestrial carbon sinks. [ABSTRACT FROM AUTHOR]

The Greater Bird-of-Paradise (Paradisaea apoda) is a bird that performs a courtship display (lekking) to attract females during the mating season. The objective of this study was to examine the display behavior of adult and sub-adult males on lek trees as a learning process by a sub-adult and identify the lek trees. The research was conducted in the Tunas Timber Lestari Ltd. Production Forest in central mainland Papua, in a non-breeding season. After a lek tree was found, a video recording was conducted. Analysis was performed from the video. The lek tree was an emergent species with a dense canopy. An adult male was observed to perform a dance display in front of sub-adult males, even in the absence of females. When adult males performed display, the sub-adult were observed the adult males in an upside-down position. The sub-adult also danced, but not as complete as the adult, suggesting that there was a learning process by the sub-adult. This study revealed that the sub-adult/young males of the bird-of-paradise has the ability to dance inherit from their fathers, and then perfect the dance through practice and watching adults. The lek tree surely need to be protected for the survival for this species. [ABSTRACT FROM AUTHOR]

Beryllium-10 cosmic-ray exposure (CRE) dating has revolutionized our understanding of glacier fluctuations around the globe. A key prerequisite for the successful application of this dating method is the determination of regional production rates of in situ accumulated 10 Be, usually inferred at independently dated calibration sites. Until now, no calibration site has been available for the mid-elevation mountain ranges of central Europe. We fill this gap by determining in situ 10 Be concentrations in large boulders on moraines and by applying radiocarbon and infrared-stimulated luminescence (IRSL) dating to stratigraphically younger lake sediments in the southern Black Forest, SW Germany. The dating methods yielded concordant results, and, based on age–depth modelling with 14 C ages, the age of a cryptotephra, and IRSL ages, we deduced a regional 10 Be production rate in quartz. Calibrating the Black Forest production rate (BFPR) in the Cosmic-Ray Exposure program (CREp) resulted in a spallogenic sea-level and high-latitude (SLHL) production rate of 3.64±0.11 atoms 10 Be g -1 quartz a -1 when referring to time-dependent Lal–Stone scaling, the European Reanalysis (ERA)-40 atmosphere model, and the atmospheric 10 Be-based geomagnetic database in CREp. The BFPR turned out to be ∼11 % lower than both those at the nearest calibration site in the Alps (4.10±0.10 atoms 10 Be g -1 quartz a -1 at SLHL) and the canonical global 10 Be production rate (4.11±0.19 atoms 10 Be g -1 quartz a -1 at SLHL) in CREp. A stronger weathering and snow cover bias and a higher impact of forest, soil, moss, and shrub cover at the study site likely explain this discrepancy. [ABSTRACT FROM AUTHOR]

Background: Drought adaptation is critical to many tree species persisting under climate change, however our knowledge of the genetic basis for trees to adapt to drought is limited. This knowledge gap impedes our fundamental understanding of drought response and application to forest production and conservation. To improve our understanding of the genomic determinants, architecture, and trait constraints, we assembled a reference genome and detected ~ 6.5 M variants in 432 phenotyped individuals for the foundational tree Corymbia calophylla. Results: We found 273 genomic variants determining traits with moderate heritability (h2SNP = 0.26–0.64). Significant variants were predominantly in gene regulatory elements distributed among several haplotype blocks across all chromosomes. Furthermore, traits were constrained by frequent epistatic and pleiotropic interactions. Conclusions: Our results on the genetic basis for drought traits in Corymbia calophylla have several implications for the ability to adapt to climate change: (1) drought related traits are controlled by complex genomic architectures with large haplotypes, epistatic, and pleiotropic interactions; (2) the most significant variants determining drought related traits occurred in regulatory regions; and (3) models incorporating epistatic interactions increase trait predictions. Our findings indicate that despite moderate heritability drought traits are likely constrained by complex genomic architecture potentially limiting trees response to climate change. [ABSTRACT FROM AUTHOR]

The novelty claims in carbon forestry often obscure the complex histories and the colonial entanglements of carbon forest socioecologies. This paper argues that the conditions of possibility of carbon forestry in ‘Nigeria’s last rainforest’ are tightly linked to the uneven colonial production of forests across Southern Nigeria. Drawing on archival research, ethnographic fieldwork and analysis of program documents and academic literature, the paper unsettles claims of novelty in Nigeria’s carbon forestry by demonstrating the material continuity between colonial forestry and carbon forestry. Focusing on the development of colonial forestry in Southern Nigeria under British colonial rule, the paper traces the coloniality of scientific forestry as a form of environmental rule, and its entanglements with imperial capitalism and presumptions of racial hierarchy. If the success of scientific forestry in Southern Nigeria meant the draining of Nigeria’s forests as timber export, its failure in Cross River paradoxically produced ‘Nigeria’s last rainforest,’ a literal ‘colonial residue’ . In colonial forestry, as in contemporary carbon forestry, a reductionist knowledge of forests, capitalist interests and a racialized global division of labor all interact in consequential ways. The paper concludes that decolonizing Nigeria’s forestry is a precondition for saving its ‘last rainforest.’ [ABSTRACT FROM AUTHOR]

The essential biodiversity variables (EBV) framework has been proposed as a monitoring system of standardized, comparable variables that represents a minimum set of biological information to monitor biodiversity change at large spatial extents. Six classes of EBVs (genetic composition, species populations, species traits, community composition, ecosystem structure and ecosystem function) are defined, a number of which are ideally suited to observation and monitoring by remote sensing systems. We used moderate-resolution remotely sensed indicators representing two ecosystem-level EBV classes (ecosystem structure and function) to assess their complementarity and redundancy across a range of ecosystems encompassing significant environmental gradients. Redundancy analyses found that remote sensing indicators of forest structure were not strongly related to indicators of ecosystem productivity (represented by the Dynamic Habitat Indices; DHIs), with the structural information only explaining 15.7% of the variation in the DHIs. Complex metrics of forest structure, such as aboveground biomass, did not contribute additional information over simpler height-based attributes that can be directly estimated with light detection and ranging (LIDAR) observations. With respect to ecosystem conditions, we found that forest types and ecosystems dominated by coniferous trees had less redundancy between the remote sensing indicators when compared to broadleaf or mixed forest types. Likewise, higher productivity environments exhibited the least redundancy between indicators, in contrast to more environmentally stressed regions. We suggest that biodiversity researchers continue to exploit multiple dimensions of remote sensing data given the complementary information they provide on structure and function focused EBVs, which makes them jointly suitable for monitoring forest ecosystems. [ABSTRACT FROM AUTHOR]

A recently proposed modelling strategy predicts the net primary production (NPP) of forest ecosystems by combining the outputs of a NDVI-driven model, Modified C-Fix, and a bio-geochemical model, BIOME-BGC. This combination strategy takes into account the effects of forest disturbances but still assumes the presence of a mixture of differently aged trees. The application of this strategy to even-aged forests, therefore, requires a methodological advancement aimed at properly modifying the modelling of main ecosystem processes. In particular, the adaptation of the method to even-aged forests is based on the use of high-spatial-resolution airborne laser scanning (ALS) datasets, which yields green and woody biomass estimates that regulate the simulation of photosynthetic and respiratory processes, respectively. This approach was experimented in a Mediterranean study area, San Rossore Regional Park (Central Italy), which is covered by even-aged pine stands in different development phases. The modelling strategy is driven by MODIS NDVI images and meteorological data across five years (2011–2015), which are combined with estimates of forest canopy cover and height obtained from ALS data taken in 2015. This allows the production of stand NPP estimates, which, when converted into respective current annual increment (CAI) values, reasonably reproduce the age dependency of the available ground observations. The CAI estimates also show a highly significant correlation with these observations (r = 0.773) and moderate error levels (RMSE = 2.03 m3 ha−1 year−1, MBE = −0.45 m3 ha−1 year−1). These results confirm the potential of the modified simulation method to yield accurate high-spatial-resolution NPP estimates, which can offer valuable insights into C cycling and storage, in even-aged forests. [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]

Forestry plantations have been expanded to meet the increasing demand for tree products, impacting evapotranspiration rates and hydrology. We explore how three Eucalyptus spp. respond to environmental resources using productivity and water use efficiency as indicators. Environmental variables, tree transpiration, soil physical properties, soil water content, and plant productivity were monitored. Eucalyptus saligna was the most productive, with higher volume, basal area and average annual increment compared to E. benthamii and E. dunnii. Transpiration of E. saligna (1249 mm year−1) was also higher than that of E. benthamii (928 mm year−1) and E. dunnii (733 mm year−1). The highest water use efficiency was evident for E. dunnii. Soil water rarely limited plant growth. Nevertheless, annual transpiration for E. saligna exceeded annual rainfall. Eucalyptus species with high water use should be avoided in areas of limited water availability, while species with low water use can provide productivity without depleting water resources. [ABSTRACT FROM AUTHOR]

Basic ecological theory suggests that a tradeoff between competitiveness and stress tolerance dictates species range limits at regional extents. However, empirical support for this key theory remains deficient because the necessary spatial and temporal coverage and scalability of field observations has rarely been achieved. We harnessed an extensive dendroecological network (> 22 000 tree‐ring samples from 816 forest inventory plots) to disentangle competition‐limited from climate‐limited growth in both overstory and understory trees. Growth synchrony among trees thereby served as an integral metric of climate sensitivity, an approach that we justify in supplementary analyses of growth responses to temperature, precipitation, and the standardized precipitation‐evapotranspiration index. Sampling plots were arranged along elevational climate and vegetation gradients throughout the Carpathian Mountains, ranging from mixed‐species lowland forests to coniferous forests at high elevations. With mixed‐effect modelling, we also identified non‐climatic factors (stand characteristics, species diversity, and disturbance history) that modulate spatial patterns in the growth rate and synchrony of European beech Fagus sylvatica and Norway spruce Picea abies. Beech exhibited reduced growth and increased climate sensitivity towards higher elevations but performed better when species diversity was higher. The growth of spruce increased towards its lower range boundary, but understory cohorts grew poorly under interspecific competition. Overall, climate sensitivity was lower in more productive stands with benign climatic conditions and in recently disturbed sites with reduced stand density. These contrasting performances at mid‐elevations where the two species overlap (900–1300 m a.s.l.) reflect their evolutionary history, which enables them to be competitive (beech) or cold‐stress tolerant (spruce). This history will affect interactions between the two species under climate warming and shape macroecological patterns in the Carpathian ecoregion and likely other parts of Europe. Our findings point to a growing advantage of competitively stronger species in montane and subalpine vegetation zones. [ABSTRACT FROM AUTHOR]

Many land surface models (LSMs) assume a steady‐state assumption (SS) for forest growth, leading to an overestimation of biomass in young forests. Parameters inversion under SS will potentially result in biased carbon fluxes and stocks in a transient simulation. Incorporating age‐dependent biomass into LSMs can simulate real disequilibrium states, enabling the model to simulate forest growth from planting to its current age, and improving the biased post‐calibration parameters. In this study, we developed a stepwise optimization framework that first calibrates "fast" light‐controlled CO2 fluxes (gross primary productivity, GPP), then leaf area index (LAI), and finally "slow" growth‐controlled biomass using the Global LAnd Surface Satellite (GLASS) GPP and LAI products, and age‐dependent biomass curves for the 25 forests. To reduce the computation time, we used a machine learning‐based model to surrogate the complex integrated biosphere simulator LSM during calibration. Our calibrated model led to an error reduction in GPP, LAI, and biomass by 28.5%, 35.3% and 74.6%, respectively. When compared with net biome productivity (NBP) using no‐age‐calibrated parameters, our age‐calibrated parameters increased NBP by an average of 50 gC m−2 yr−1 across all forests, especially in the boreal needleleaf evergreen forests, the NBP increased by 118 gC m−2 yr−1 on average, increasing the estimate of the carbon sink in young forests. Our work highlights the importance of including forest age in LSMs, and provides a novel framework for better calibrating LSMs using constraints from multiple satellite products at a global scale. Plain Language Summary: Physical and biological process‐based models always overestimate the biomass of young forests, with an assumption that they usually hold maximum carbon stocks like old‐growth stands. Such an assumption can lead to biased carbon fluxes and stocks in further simulation. Considering stand age in LSMs improves their ability to simulate real forest growth. In this study, we develop a stepwise method to account for stand age effects in model simulations by assimilating remotely sensed information on vegetation productivity, leaf area, biomass, and age. To reduce the computational cost of the complex original code, we use a substitute model constructed using a machine learning method for calculations. The improved model successfully reproduces the changes in ecosystem biomass and fluxes as forest age varies. Our research provides a novel approach to improving other land surface models for predicting age‐dependent ecosystem properties. Key Points: We presented a stepwise calibration framework for better integrating age‐dependent biomass into the integrated biosphere simulator modelWe utilized a machine learning‐based model as an alternative to the physical model, accelerating the calibration processThe calibration noticeably improved the simulation of gross primary productivity, leaf area index, and biomass [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]

Forest plantations play an increasingly important role in meeting global demand for wood. They usually have higher yield than naturally regenerated forests. Thus, plantations can support economically viable wood production, enable forest conservation elsewere, help mitigate climate change by contributing to carbon sequestration and increase forest resilience and resistance to biotic and abiotic stressors. If yield of plantations is not as high as anticipated, then their use could generate important sustainability issues. There are still major gaps in our understanding of the factors that influence yield, even with respect to black spruce, white spruce, and jack pine, three of the most commonly planted tree species in northeastern North America. Our objective was to evaluate the yield of forest plantations of these species over a 416 000 km2 region that was representative of northeastern North American forests. Contrary to our prediction, realized yield of operational plantations was consistently lower than anticipated. Site index and competition both played a significant role in determining the yield of plantations. In the context of uncertain realized yield of operational plantations, we emphasize the necessity of relying on adaptive management to determine harvest levels that are compatible with sustainable management objectives. [ABSTRACT FROM AUTHOR]

Economies and livelihoods in the Caribbean strongly depend on the terrestrial and marine natural resource base. There are critical gaps in quantitative data and the contextual and compositional factors affecting perceptions of changes in ecosystems and natural resources. This paper used interview data from 441 households in Belize, Dominican Republic, and Suriname to explore the contextual and compositional determinants of perceptions of change in the quality of the terrestrial, coastal/marine environment and natural resources as a composite variable. The outcome variable comprised changes in fishing effort, marine and coastal environment, forest cover, agricultural land area, and soil fertility, and relationships with predictor variables were explored using univariate, bivariate, and three multivariate models. At the univariate level, most respondents in Belize and Suriname reported perceiving a significant increase in fishing effort (i.e. days and fuel spent at sea) and a decrease in forest cover, quality of the coastal/marine environment, area of agricultural land, and fertility and productivity of soils. Sex, marital status, household size, and years of experience were not significantly associated with the terrestrial variables and fishing effort. Sex was only significantly associated with the quality of the marine environment. At the multivariate level, the elderly, high school education, and household incomes were associated with a lower perception of the outcome variable. It is concluded that policy and interventions should strongly consider ethnicity and community, and improve education and household incomes to enhance perceptions of changes in the quality of the terrestrial and coastal/marine environment in the studied countries. [ABSTRACT FROM AUTHOR]

In the Mediterranean region, inner rural and mountain areas suffered abandonment and land marginalization. Extensive conifer afforestations were established in these areas, which are particularly vulnerable to climate change and its associated risks. To identify critical areas where climate change could negatively impact forest vitality, we need to understand how the temporal variability of tree growth and its vulnerability to climate and drought have arisen and what their possible causes are. We used dendrochronological techniques to examine the effects of stand structure, physiography, and local climate variations in determining the growth dynamics of Aleppo pine plantations and temporal shifts in their susceptibility to hydroclimate and drought in semi-arid northeastern Spain. We found that structural traits strongly modulated growth dynamics and forest productivity. Young and small trees showed more synchronized growth and greater inter-annual ring width variability, and widely spaced trees in better quality stands had higher productivity. In contrast, temporal shifts in growth susceptibility to hydroclimate and drought were dependent on local physiography and climatic variability. Trees in low-elevation eastern stands with less continental conditions and milder winters showed decreasing dependence on water availability and increasing growth resistance and resilience to severe droughts. However, in high-elevation sites with wetter climates and cold winters, increasing growth response to water availability and decreasing resistance and resilience to drought were found. Our results highlight that adaptation to local physiographic and climatic conditions is a better strategy to mitigate the impacts of climate warming on Aleppo pine plantations in the semi-arid Mediterranean region. [ABSTRACT FROM AUTHOR]

Productive capacity of soils is seriously affected by erosion, causing significant environmental damages. Soil erosion led to instability in ecosystems and decline in agriculture productivity as well as in forest territories. The negative anticipation about climate hesitation for acceleration soil erosion shows the need for monitoring the condition of the soils and taking adequate measures to reduce the risk. For that reason, different models for assessing soil erosion risk and determining potential levels of erosion are strongly advocated in researches. Two of the well-known and commonly used empirical models for the territory of Balkans are Erosion Potential Method (EPM) and Universal Soil Loss Equation (USLE). The objective of the research is to apply EPM and USLE models at the Sedelska River watershed, tributary of Struma River (Southwest Bulgaria), to assess soil erosion risk and investigate its spatial distribution. The results of the two methods are compared, finding that the EPM method slightly underestimates the final results compared to the USLE methodology. In both models, the territories with the strongest erosion risk were determined, and some of them coincide. When applying the USLE, it was found that the largest area of the research site is occupied by the lands on which a low actual risk is observed (47.10%). From the results obtained when applying the EPM, the watershed falls into the third degree of the Gavrilovich scale - a watershed with moderate erosion. The average amount of soil eroded assess with EPM is 3 t/ha/y. According to USLE the average potential risk with amounts of eroded soil of 100-200 t/ha y. [ABSTRACT FROM AUTHOR]

The land sink of anthropogenic carbon emissions, a crucial component of mitigating climate change, is primarily attributed to the CO2 fertilization effect on global gross primary productivity (GPP). However, direct observational evidence of this effect remains scarce, hampered by challenges in disentangling the CO2 fertilization effect from other long‐term confounding drivers, particularly climatic changes. Here, we introduce a novel statistical approach to separate the CO2 fertilization effect on photosynthetic carbon uptake using eddy covariance (EC) records across 38 extratropical forest sites. We find the median stimulation rate of GPP to be 3.2 ± 0.9 gC m−2 yr−1 ppm−1 (or 16.4 ± 4.2% per 100 ppm) under increasing atmospheric CO2 across these sites, respectively. To validate the robustness of our findings, we test our statistical method using factorial simulations of an ensemble of process‐based land surface models. We address additional factors, including nitrogen deposition and land management, that may impact plant productivity, potentially confounding the attribution to the CO2 fertilization effect. Assuming these site‐specific effects offset to some extent across sites as random factors, the estimated median value still reflects the strength of the CO2 fertilization effect. However, disentanglement of these long‐term effects, often inseparable by timescale, requires further causal research. Our study provides direct evidence that the photosynthetic stimulation is maintained under long‐term CO2 fertilization across multiple EC sites. Such observation‐based quantification is key to constraining the long‐standing uncertainties in the land carbon cycle under rising CO2 concentrations. Plain Language Summary: Through photosynthesis, plants convert CO2 and water into sugars and oxygen using solar energy, one of the most important chemical reactions on Earth. Human‐made carbon emissions are increasing atmospheric CO2 levels, impacting global photosynthesis. The additional carbon is believed to have a fertilizing effect on photosynthesis, causing vegetation to absorb a significant portion of the emitted CO2. However, the strength of this CO2 fertilization effect on photosynthesis is uncertain, but is a crucial factor in determining the future trajectory of atmospheric CO2 concentrations. In this study, we introduce a new statistical method to quantify the increase in photosynthetic carbon uptake, stimulated by rising CO2, based on measurements from 38 forest sites. Our results reveal that a 100 ppm increase in CO2 enhances photosynthesis by approximately 16%. Testing the statistical method with artificial model experiments supports the robustness of our findings. Our study improves the understanding of the impacts of human‐made CO2 emissions on the global carbon cycle. Key Points: We present a novel statistical method to disentangle the variability of photosynthetic rates related to climate and non‐climate driversThe analysis from 38 eddy covariance sites reveals a 3.2 ± 0.9 gC m−2 yr−1 increase in plant productivity per ppm rise in CO2Our statistical method is successfully tested against idealized model simulations with and without increasing CO2 [ABSTRACT FROM AUTHOR]