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Forest ecosystems play a vital role in balancing the global climate through functions such as regulating carbon emissions, carbon sequestration, and energy and water cycles. Aboveground biomass (AGB) is a critical component in forest management to understand better and predict the global carbon cycle. However, traditional methods used in AGB measurement involve time-consuming, costly, and labor-intensive processes. Sentinel-1 (active), Sentinel-2, and Landsat (passive) satellite imagery, which is freely accessible and offers global coverage with frequent updates, and recently developed remote sensing platforms such as Unmanned Aerial Vehicle (UAV) serve as a valuable data source for consistent and continuous monitoring of aboveground biomass. This research focuses on modeling the relationships between AGB and data obtained from various remote sensing sources, including Sentinel-1, Sentinel-2, Landsat 8, and UAV imagery, within pure Scots pine stands in northern Türkiye. The study employs multiple linear regression (MLR) and artificial neural networks (ANNs) to establish these relationships. AGB values for each sample plot were calculated using an allometric equation. Backscatter coefficients and band brightness values were extracted from Sentinel-1 imagery, while reflectance values and vegetation indices were generated from Sentinel-2, Landsat 8 OLI, and UAV imagery. Additionally, texture features were computed for varying window sizes (3 × 3, 5 × 5, 7 × 7, 9 × 9, 11 × 11, 13 × 13, and 15 × 15) and orientations (0°, 45°, 90°, and 135°) based on data from Sentinel-2 and Landsat 8 OLI images for each sample plot. The relationships between remote sensing data and AGB were modeled using both MLR and ANN techniques. The findings revealed that the most accurate AGB estimation (R²=0.82; RMSE = 0.35 ton ha⁻¹) was achieved using the texture variables derived from the 9 × 9 window size of Sentinel-2 imagery via the ANNs modeling approach, outperforming other image sources and MLR analysis. [ABSTRACT FROM AUTHOR]

Increasing evidence shows that biodiversity–ecosystem functioning relationships (BEFs) become stronger as forests develop, but much of the evidence is drawn from experiments (less than 30 years). How the biodiversity effects vary with stand development stages remains largely unexplored. Using a large temperate forest dataset with 2392 permanent plots in northeastern China, we examined the relationships between biodiversity (i.e. tree species richness, functional diversity, and functional composition) and aboveground biomass (AGB) across different development stages of temperate forests (covering all stages from young to overmature forests). Specifically, the complementarity and mass‐ratio effects across different forest development stages were evaluated to elucidate emerging patterns that explain ecosystem functioning. We observed positive BEFs using both tree species richness and functional diversity, but these positive effects decreased with forest development. However, the effects of community‐weighted mean (CWM) on AGB showed two peaks in young and mature stands. Interestingly, the effects of CWM on AGB became larger than the effects of functional diversity after the forests developed to near‐mature/mature stands, indicating that BEFs are driven by mass‐ratio effects (i.e. dominant tree species) rather than niche complementarity in old stands. The high AGB in young stands was characterized by tree species with high resource acquisition ability, however, in old stands, it was associated with tree species with both high resource acquisition ability and conservative traits. Our findings indicate how the developmental stage influences the effects of biodiversity on ecosystem functioning in natural forests. The findings tentatively advocate for a mechanistic framework of BEFs covering all developmental stages of temperate forests, which could facilitate the formulation of effective strategies for enhancing ecosystem functioning at different development stages. [ABSTRACT FROM AUTHOR]

Climate warming is projected to affect hydrological cycle in forest ecosystems and makes the forest–water relationship more controversial. Currently, planted forests are gaining more public attention due to their role in carbon sequestration and wood production relative to natural forests. However, little is known about how the global patterns and drivers of water yield and water‐use efficiency (WUE) differ between planted and natural forests. Here, we conduct a global analysis to compare water yield and WUE in planted and natural forests using 946 observations from 112 published studies. The results showed that global average water yield coefficient was 0.29 for planted forests and 0.34 for natural forests. Planted forests exhibited lower water yield coefficient (p < 0.05) in three climatic regions (arid, dry subhumid, and humid regions), but higher (p < 0.01) WUE only in arid region, compared with natural forests. Both water yield coefficient and WUE in planted forests were significantly lower (p < 0.05) than that in natural forests for stand characteristic groups (stand density, average tree height, leaf area index [LAI], and basal area). Additionally, stand density within the ranging between 1000 to 2000 stem ha−1 can maximize the water yield and WUE in planted and natural forests. Water yield coefficient in planted forests was primarily controlled by the factors related to tree growth (i.e., tree height, DBH), while that of natural forest mainly affected by stand structure (i.e., LAI, stand density, DBH). WUE in planted forest was more sensitive to climate than in natural forests. This work highlights the critical role of natural forests in water supply and the importance of tree species selection and stand management (e.g., stand density adjustment) in plantations in future forest restoration policies and climate change mitigation. [ABSTRACT FROM AUTHOR]

Land cover is a crucial factor in controlling rainfall–runoff processes in mountain basins. However, various anthropogenic activities, such as converting natural vegetation to agricultural or urban areas, can affect this cover, thereby increasing the risk of flooding in cities. This study evaluates the hydrological behavior of two mountain basins in Loja, Ecuador, under varying land use scenarios. El Carmen small basin (B1), located outside the urban perimeter, and Las Pavas small basin (B2), within the urban area, were modeled using HEC-HMS 4.3 software. The results highlight the significant influence of vegetation degradation and restoration on hydrological processes. In degraded vegetation scenarios, peak flows increase due to reduced soil infiltration capacity, while baseflows decrease. Conversely, the conserved and restored vegetation scenarios show lower peak flows and higher baseflows, which are attributed to enhanced evapotranspiration, interception, and soil water storage. The study underscores the importance of ecosystem management and restoration in mitigating extreme hydrological events and improving water resilience. These findings provide a foundation for decision-making in urban planning and basin management, emphasizing the need for comprehensive and multidisciplinary approaches to develop effective public policies. [ABSTRACT FROM AUTHOR]

This study aimed to emphasize the key role of spatial morphology of planted and natural forests on landscape fragmentation and to furnish a scientific foundation for the effective assessment of ecological restoration projects of vegetation on the Loess Plateau. The spatial morphological pattern and landscape fragmentation characteristics were analyzed using morphological spatial pattern analysis (MSPA) and forest area density methods. This is the inaugural study to reveal the linear and nonlinear relationships between forest landscape fragmentation and its driving factors using machine learning methods and introducing morphological indicators with two different strategies. The results showed significant differences in the spatial patterns and landscape fragmentation characteristics between planted and natural forests. The spatial patterns of planted and natural forests were found to be dominated by "Core" in terms of area, while "Branch" was more prevalent in terms of number. Compared to natural forests, planted forests were more fragmented. The introduction of the MSPA indicator significantly enhanced the explanatory power and predictive performance of the model despite the disparate contribution rates of the driving factors in planted and natural forests. This study highlights the importance of spatial morphology in understanding forest landscape fragmentation and provides a new combination of analytical techniques to better understand the complexity of forest ecosystems. These provide new insights into forest landscape restoration and sustainable management on the Loess Plateau. [ABSTRACT FROM AUTHOR]

Forests have seen a strong greening trend worldwide, and previous studies have attributed this mainly to land‐use conversions such as afforestation. However, for the greening of existing forests, the role of human interventions is unclear. Here we paired neighboring natural and planted forests in Southern China to minimize the differences between the forest types and analyzed the vegetation index EVI2 from Landsat over 1987 to 2021. The EVI2 trends observed in natural forests can be seen as mainly responses to large‐scale environmental changes, whereas the difference between the forest types represents the impact caused by human interventions. We found that though the mean EVI2 of planted forests was comparable to that of natural forests, the greening trends were overall 7.0% lower in planted forests. Our results suggest that human interventions associated with planted forests did not accelerate their greening, indicating the necessity for refined policies to enhance future forest greening. Plain Language Summary: General greening of forests has been reported worldwide. While previous studies have tended to attribute forest greening to land‐use conversions such as re‐ and afforestation, the role of human interventions for existing forests is still unclear. The greening trend of natural forests are mainly impacted by environmental changes, whereas those in planted forests are also influenced by human interventions. Therefore, the comparison of greening trends between the two forest types can help quantitatively distinguish the role of human interventions. Here, we paired spatially adjacent natural forests with planted forests in Southern China, and performed a pairwise comparisons of greenness and its trend between the forest types over 1987 to 2021 based on Landsat satellite series. It was found that although their mean greenness was similar, the greening trends of planted forests were 7.0% lower than the natural forests. Thus, human interventions may lead to a weakened greening trend while environmental changes were likely the main driver of greening of existing forests in Southern China. Such distinction of drivers is key for our understanding of the impact of environmental changes, land use and land use change, and for designing policies that put us on a pathway to a more sustainable future. Key Points: Planted forests showed slightly lower greenness than paired natural forests in Southern China from 1987 to 2021Over the past 40 years, the greening trends of planted forests were overall 7.0% lower than natural forests in Southern ChinaEnvironmental change, and not human interventions, was likely the dominant cause of observed greening in Southern China [ABSTRACT FROM AUTHOR]

To explore variations in carbon storage and distribution patterns across various layers(vegetation layer, litter layer, and soil layer)of different age classes and different densities of Picea schrenkiana var. tianschanica natural forest ecosystem in the northern foot of Tianshan Mountains, a total of 9 kinds of P. schrenkiana var. tianschanica natural forest with low(300～500 tree·hm-2), medium(500～600 tree·hm-2)and high(600～800 tree·hm-2)stand densities under three age classes of the middle-aged forest, near-mature forest and mature forest were selected as the research objects. Carbon storage at different levels in the natural forest ecosystem of P. schrenkiana var. tianschanica was estimated by field investigation and indoor analysis. The results showed that for the aboveground and belowground biomass of tree layer components in P. schrenkiana var. tianschanica, natural forest increased with an increase in stand density in middle-aged and near-mature forests. In contrast, in mature forests, it increased first and then decreased with an increase in stand density. In the herb and litter layers of the natural forest of P. schrenkiana var. tianschanica, the biomass of the litter layer was the main component, accounting for 74. 46%～99. 45%; the herb layer components accounted for only 0. 55%～25. 54%. The vegetation carbon storage of the P. schrenkiana var. tianschanica natural forest increased with an increase in stand density in the middle-aged forest but decreased first and then increased with an increase in stand density in near-mature and mature forests. Soil carbon storage in the P. schrenkiana var. tianschanica natural forest first decreased and then increased with an increase in age class and stand density. The ecosystem carbon storage was the highest in the middle-aged high-density stand(570. 65 t·hm-2)and the lowest in the middle-aged low-density stand(287. 21 t·hm-2). The spatial distribution pattern of carbon storage in the P. schrenkiana var. tianschanica natural forest ecosystem was as follows: carbon storage in the soil layer accounted for the highest proportion, which was 49. 74%～72. 92%, followed by carbon storage in the tree layer(30. 22%～49. 54%), and the proportion of carbon storage in the herb and litter layers was only 0. 32%～2. 28%. The soil layer serves as the primary carbon reservoir in the natural Schrenkiana spruce forest ecosystem, allowing it to effectively store organic carbon as it grows. Middle-to-high-density forests contribute to the accumulation of biomass and carbon. High-density forests in near-mature and mature forests should be moderately thinned to increase the carbon sequestration capacity of the stands. [ABSTRACT FROM AUTHOR]

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Multiplatform fusion point clouds can effectively compensate for the disadvantages of individual platform point clouds in forest parameter extraction, maximizing the potential of LiDAR technology. However, existing registration algorithms often suffer from insufficient feature extraction and limited registration accuracy. To address these issues, we propose a ULS (Unmanned Aerial Vehicle Laser Scanning)-TLS (Terrestrial Laser Scanning) point cloud data registration method based on Similar Distance Search (SDS). This method enhances coarse registration by accurately retrieving points with similar features, leading to high overlap in the rough registration stage and further improving fine registration precision. (1) The proposed method was tested on four natural forest plots, including Pinus densata Mast., Pinus yunnanensis Franch., Pices asperata Mast., Abies fabri (Mast.) Craib, and demonstrated high registration accuracy. Both coarse and fine registration achieved superior results, significantly outperforming existing algorithms, with notable improvements over the TR algorithm. (2) In addition, the study evaluated the accuracy of individual tree parameter extraction from fusion point clouds versus single-platform point clouds. While ULS point clouds performed slightly better in some metrics, the fused point clouds offered more consistent and reliable results across varying conditions. Overall, the proposed SDS method and the resulting fusion point clouds provide strong technical support for efficient and accurate forest resource management, with significant scientific implications. [ABSTRACT FROM AUTHOR]

Simple Summary: Climate change will cause a reduction in the provision of goods and services of Mediterranean forests, including those of stone pine (Pinus pinea), an economically important species. We used a dendrochronological approach to address climate impact on the growth of stone pine natural stands and plantations. Our results indicate that increasingly arid conditions will affect both natural stands and plantations in native and exotic countries. Adaptive management will be essential to ensure the maintenance of the stands and their multifunctionality. Pinus pinea is an important Mediterranean species due to its adaptability and tolerance to aridity and its high-quality pine nuts. Different forest types located in Mediterranean native and non-native environments provide the opportunity to perform comparative studies on the species' response to climate change. The aims of this study were to elucidate growth patterns of the species growing in native and exotic habitats and to analyze its response to climatic fluctuations, particularly drought, in both geographical contexts. Understanding stone pine (Pinus pinea) growth responses to climate variability in native and exotic habitats by comparing natural stands and plantations may provide useful information to plan adequate management under climate change. By doing so, we enhance the understanding of P. pinea's adaptability and provide practical approaches to its sustainable management. In this study, we reconstructed and compared the stem radial growth of seven stone pine stands, two in southern Spain and five in central–southern Chile, growing under different climatic conditions. We quantified the relationships between growth variability and climate variables (total rainfall, mean temperature, and SPEI drought index). Growth was positively correlated with autumn rainfall in plantations and with autumn–winter rainfall in natural stands. Growth was also enhanced by high autumn-to-spring rainfall in the driest Chilean plantation, whereas in the wettest and coolest plantation, such correlation was found in winter and summer. A negative impact of summer temperature was found only in one of the five Chilean plantations and in a Spanish site. The correlation between SPEI and tree-ring width indices showed different patterns between and within countries. Overall, exotic plantations showed lower sensitivity to climate variability than native stands. Therefore, stone pine plantations may be useful to assist in mitigating climate change. [ABSTRACT FROM AUTHOR]

Abstract Background Forests play a crucial role in absorbing CO2 from the atmosphere. 55% of the carbon in terrestrial ecosystems is stored in forests, with the majority of forest carbon stored in soil. To better understand soil organic carbon (SOC) of forests and to access interventions that affect their SOC concentration, we conducted a comparative analysis between natural and planted forests. Forest interventions refer to the actions taken by humans to manage, protect, or transform forests, and can be divided into two main categories: environmental intervention and anthropogenic intervention. This study focused on the effects of different interventions on SOC in natural and planted forests by reviewing a total of 75 randomized controlled trials in the global literature and extracting a total of 15 different interventions. Results Through network meta-analysis, we found that natural forests have 22.3% higher SOC than planted forests, indicating their stronger carbon storage function. In natural forests, environmental interventions have a stronger impact. SOC is significantly influenced by forest age, fertilization, and elevation. In planted forests, however, anthropogenic interventions have a stronger impact. Pruning branches and fertilization are effective interventions for planted forests. Furthermore, forest degradation has a significantly negative impact on SOC in planted forests. Conclusion Overall, interventions to enhance soil carbon storage function differ between natural and planted forests. To address global climate change, protect biodiversity, and achieve sustainable development, it is imperative to globally protect forests and employ scientifically sound forest management practices. Regarding natural forests, the emphasis should be on comprehending the effects of environmental interventions on SOC. Conversely, concerning planted forests, the emphasis should be on comprehending the effects of anthropogenic interventions.

Understanding soil organic carbon (SOC) and total nitrogen (TN) stock changes is crucial for designing effective strategies that sequester carbon and enhance soil fertility. This study examined the effects of slope aspect, watershed management practices, and slope position on SOC and TN stocks in the Upper Gelana watershed of Ethiopia. Sixty auger samples and sixty undisturbed core samples (0–30 cm) were collected. Data were subjected to a three-way general linear model. The results showed that watershed management practices and slope positions significantly influenced SOC and TN stock distributions (p < 0.05). Carbon-to-nitrogen ratios were affected considerably by slope aspect and slope position (p < 0.01). SOC stocks ranged from 20.65 Mg ha−1 in open grazing lands to 51.32 Mg ha−1 in natural forests, while TN stocks varied from 1.77 Mg ha−1 in traditional farming to 4.5 Mg ha−1 in controlled grazing systems. Both SOC and TN stock losses in open grazing and traditional farming reached 60 % and 59 %, respectively. Annual SOC stock gains in controlled grazing, agroforestry, and stabilized bund systems were 1.13, 0.82, and 0.51 Mg ha−1, respectively, with a 24-year restoration period. Natural forests had higher SOC and TN stocks in the east-facing aspect, while controlled grazing showed better results in the west-facing aspect. These findings emphasize the importance of expanding controlled grazing and agroforestry systems, alongside forest restoration, as an integrated watershed management approach for enhancing soil fertility and carbon sequestration. The results underscore the importance of considering topographic factors in land use planning to optimize nutrient dynamics.

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]

Natural forests are crucial for climate change mitigation and adaptation, but deforestation and degradation challenges highly reduce their value. This study evaluates the potential of natural forest carbon stock and the influence of management interventions on enhancing forest carbon storage capacity. Based on forest area cover, a study was conducted in nine purposely selected forest patches across various forest ecosystems. Data on diameter, height, and environmental variables from various forest management approaches were collected and analyzed with R Ver. 4.1. The findings revealed a substantial difference (p.029) in carbon stock between environmental variables and management interventions. The findings revealed a strong connection between environmental variables and the overall pool of carbon stock within forest patches (p.029). Carbon stocks were highest in the Moist‐montane forest ecosystem (778.25 ton/ha), moderate slope (1019.5 ton/ha), lower elevation (614.50 ton/ha), southwest‐facing (800.1 ton/ha) and area exclosures (993.2 ton/ha). Accordingly, natural forests, particularly unmanaged parts, are sensitive to anthropogenic stresses, decreasing their ability to efficiently store carbon. As a result, the study highlighted the importance of sustainable forest management, particularly area exclosures and participatory forest management, in increasing forest carbon storage potential. [ABSTRACT FROM AUTHOR]

The objective was, therefore, to evaluate the impact on organic carbon and the formation of soil aggregates in areas of natural vegetation converted into pastures in southern Amazonas. The research was carried out in seven areas in the municipality of Humaitá, Amazonas, Brazil, five of which were pastureland, one native forest, and one natural field. Soil samples were collected at depths of 0–10 and 10–20 cm in the seven study areas and analyzed for aggregate stability, soil density, soil organic carbon, and the calculated soil organic carbon stock. Univariate, bivariate, and multivariate analyses were then carried out. Conversion from forest to pasture had a negative impact on percentage of aggregates >2 mm, soil density, concentration and stock of soil organic carbon. Organic carbon correlates positively with percentage of aggregates >2 mm, geometric mean diameter and weighted mean diameter, and negatively with soil density. Aggregate stability influences carbon sequestration in the pasture and forest areas studied, but has no influence in the natural grassland environment. [ABSTRACT FROM AUTHOR]

Forest is the largest carbon sink on land, and the timing of forest phenology profoundly influences carbon uptake. However, disparities in the timing and sensitivity of forest phenology, particularly between planted forests (PF) and natural forests (NF), have yet to be determined. In this study, we analyzed the phenological trends and the climate‐sensitivities of China's NF and PF from 2000 to 2022 using field survey data and satellite data. We found that the start of the growing season (start of the season (SOS)) in NF and PF advanced significantly by 0.07 and 0.08 days yr−1, while the end of the growing season (end of the season (EOS)) in both NF and PF delayed by 0.06 days yr−1. Moreover, precipitation and air temperature jointly influenced the timing of phenological events. The pre‐season precipitation delayed the EOS by 0.009 days mm−1 and 0.006 days mm−1 in NF and PF. Moreover, the SOS was more sensitive to precipitation in PF than in NF in arid areas (i.e., pre‐season precipitation <100 mm). Air temperature significantly advanced the SOS by 0.74 and 0.95 days °C−1 in NF and PF and delayed the EOS by 0.89 and 0.71 days °C−1 in NF and PF. Additionally, the sensitivities of SOS and EOS to air temperature significantly differed between NF and PF. Our findings demonstrate a significant phenological discrepancy between PF and NF. The results suggest that NF and PF responded differently to climate variability, implying forest origin should be considered in the projection of carbon sequestration capability under changing climate. Plain Language Summary: Phenology is an important indicator of forest's response to climate change, and its change greatly influences the carbon uptake in forests. In this study, we investigated the phenological changes in China's natural and planted forests, as well as the sensitivity of forest phenology to air temperature and precipitation. We found that the start of the growing season was earlier and the end occurred later in China's forests from 2000 to 2022. Besides, higher air temperature and precipitation could advance the start and delay the end of the growing season in China's forests, respectively. However, the magnitudes of the advancement and delay in phenology to warming and wetting were different between planted and natural forests. We suggest that future studies should consider the impacts of forest origin in biogeochemical simulations. Key Points: The start of the growing season advanced and the end delayed in China's planted and natural forestsThe planted and natural forests differed in their responses to climate variabilityThe start of the growing season was more sensitive to precipitation in planted forests than in natural forests in arid areas [ABSTRACT FROM AUTHOR]

Background: Forests play a crucial role in absorbing CO2 from the atmosphere. 55% of the carbon in terrestrial ecosystems is stored in forests, with the majority of forest carbon stored in soil. To better understand soil organic carbon (SOC) of forests and to access interventions that affect their SOC concentration, we conducted a comparative analysis between natural and planted forests. Forest interventions refer to the actions taken by humans to manage, protect, or transform forests, and can be divided into two main categories: environmental intervention and anthropogenic intervention. This study focused on the effects of different interventions on SOC in natural and planted forests by reviewing a total of 75 randomized controlled trials in the global literature and extracting a total of 15 different interventions. Results: Through network meta-analysis, we found that natural forests have 22.3% higher SOC than planted forests, indicating their stronger carbon storage function. In natural forests, environmental interventions have a stronger impact. SOC is significantly influenced by forest age, fertilization, and elevation. In planted forests, however, anthropogenic interventions have a stronger impact. Pruning branches and fertilization are effective interventions for planted forests. Furthermore, forest degradation has a significantly negative impact on SOC in planted forests. Conclusion: Overall, interventions to enhance soil carbon storage function differ between natural and planted forests. To address global climate change, protect biodiversity, and achieve sustainable development, it is imperative to globally protect forests and employ scientifically sound forest management practices. Regarding natural forests, the emphasis should be on comprehending the effects of environmental interventions on SOC. Conversely, concerning planted forests, the emphasis should be on comprehending the effects of anthropogenic interventions. [ABSTRACT FROM AUTHOR]

Different chemical compositions of soil organic carbon (SOC) affect its persistence and whether it significantly differs between natural forests and plantations remains unclear. By synthesizing 234 observations of SOC chemical compositions, we evaluated global patterns of concentration, individual chemical composition (alkyl C, O-alkyl C, aromatic C, and carbonyl C), and their distribution evenness. Our results indicate a notably higher SOC, a markedly larger proportion of recalcitrant alkyl C, and lower easily decomposed carbonyl C proportion in natural forests. However, SOC chemical compositions were appreciably more evenly distributed in plantations. Based on the assumed conceptual index of SOC chemical composition evenness, we deduced that, compared to natural forests, plantations may have higher possible resistance to SOC decomposition under disturbances. In tropical regions, SOC levels, recalcitrant SOC chemical composition, and their distributed evenness were significantly higher in natural forests, indicating that SOC has higher chemical stability and possible resistance to decomposition. Climate factors had minor effects on alkyl C in forests globally, while they notably affected SOC chemical composition in tropical forests. This could contribute to the differences in chemical compositions and their distributed evenness between plantations and natural stands. [ABSTRACT FROM AUTHOR]

Abstract Forests have seen a strong greening trend worldwide, and previous studies have attributed this mainly to land‐use conversions such as afforestation. However, for the greening of existing forests, the role of human interventions is unclear. Here we paired neighboring natural and planted forests in Southern China to minimize the differences between the forest types and analyzed the vegetation index EVI2 from Landsat over 1987 to 2021. The EVI2 trends observed in natural forests can be seen as mainly responses to large‐scale environmental changes, whereas the difference between the forest types represents the impact caused by human interventions. We found that though the mean EVI2 of planted forests was comparable to that of natural forests, the greening trends were overall 7.0% lower in planted forests. Our results suggest that human interventions associated with planted forests did not accelerate their greening, indicating the necessity for refined policies to enhance future forest greening.

Anthropogenic activities carried out by communities around forests in production forests, protected forests, and conservation forests have an impact on changes in the land cover of these areas. This impact is difficult to avoid because, on the other hand, production forests and protected forests are in direct contact with the lives of local communities. Changes in land cover have a significant impact on the contribution of Folu Net Sink, which is set by the government at 31.89% in 2030 with its efforts. This research aims to provide an overview of land cover changes that occurred in natural forests of the Eucalyptus urophylla type from 2002 to 2022. The method used in this research is a supervised/guided digital classification technique. Ground checks were also carried out in this research to match the accuracy of the image data with the actual conditions in the field. The research results show that changes in land cover in 2012 and 2017 were very extreme. Forest fires were the cause of changes in land cover during this period. Meanwhile, in 2002, 2007, and 2022, the land cover was still good, in a positive direction. The causes of changes in land cover are encroachment activities, encroachment, illegal logging, firewood theft, rice fields, forest fires, plantations, and farming. Forest preservation provides very high benefits for life on earth. Therefore, it is important to pay attention to the welfare of local communities so that they do not damage the forest, as well as increase the capacity to educate the community regarding zoning or blocks in conservation and protected forests. Apart from that, good forest management is needed to ensure forest sustainability in the future.

Abstract Background Species and structural diversity are important for understanding the formation of forest communities, key ecological processes, and improving forest ecological functions and services, but their spatial characteristics have received little attention. Based on the spatial relationships among neighbouring trees, we proposed to divide trees within a structural unit into 15 structural types, and used the univariate distributions of the uniform angle index (W), mingling (M), and dominance (U), along with four common species diversity indices, to analyse the diversity of structural types in natural forests near the Tropic of Cancer. Results Only a portion of clumped class maintained aggregation, most exhibited a random pattern. Species mixture increased exponentially across distribution classes, and abundance and richness exhibited an initial increase followed by a slight decrease. The distribution patterns of mixture classes varied from highly clustered to random, and M distributions gradually shifted from an inverted J-shaped curve to a J-shaped curve. Abundance and richness exhibited an exponential distribution, whereas the Shannon–Wiener index increased linearly. The W distribution of differentiation classes approximated a normal distribution, whereas M distributions exhibited a J shape. The U distribution of each structure type was approximately 0.2. Conclusions These results reveal the species and structural diversity characteristics of trees at the structural type level and expand our knowledge of forest biodiversity. The new method proposed here should significantly contribute to biodiversity monitoring efforts in terrestrial ecosystems, and suggests that higher standards for the simulation and reconstruction of stand structure, as well as thinning in near-natural forests, is warranted.

Land cover is a crucial factor in controlling rainfall–runoff processes in mountain basins. However, various anthropogenic activities, such as converting natural vegetation to agricultural or urban areas, can affect this cover, thereby increasing the risk of flooding in cities. This study evaluates the hydrological behavior of two mountain basins in Loja, Ecuador, under varying land use scenarios. El Carmen small basin (B1), located outside the urban perimeter, and Las Pavas small basin (B2), within the urban area, were modeled using HEC-HMS 4.3 software. The results highlight the significant influence of vegetation degradation and restoration on hydrological processes. In degraded vegetation scenarios, peak flows increase due to reduced soil infiltration capacity, while baseflows decrease. Conversely, the conserved and restored vegetation scenarios show lower peak flows and higher baseflows, which are attributed to enhanced evapotranspiration, interception, and soil water storage. The study underscores the importance of ecosystem management and restoration in mitigating extreme hydrological events and improving water resilience. These findings provide a foundation for decision-making in urban planning and basin management, emphasizing the need for comprehensive and multidisciplinary approaches to develop effective public policies.

Hamra National Park in the province of Dalarna in central Sweden was established in 1909 to protect a unique unlogged old-growth forest. In 1922, Henrik Hesselman set up two permanent plots in Hamra to be able to follow the development of the forest over time. In 2022, we re-inventoried the Scots pine-dominated plot and found that (1) the number of trees in the plot almost doubled from 593 trees in 1922 to 1013 trees in 2022, (2) Norway spruces are starting to take over the initially Scots pine-dominated plot, (3) the basal area of dead trees has increased by 286% and (4) the variability in annual Scots pine growth has increased over the studied time period. Given this strong deviation from the original state of the forest, we suggest restoring part of the forest to its early-1900s state while allowing the permanent plot to evolve naturally. [ABSTRACT FROM AUTHOR]

Soil organic carbon stock is an important universal land degradation indicator. Owing to the depletion in soil nutrients, the pace of land degradation has increased in the Western Ghats of South India. To understand the changes in surface and subsurface soil organic carbon stocks and vulnerability to land degradation upon land use change, a study was carried out along the natural forest and coffee plantation ecosystems of Western Ghats in South India. The study sites were located in Chikmagaluru of Karnataka and Wayanad and Idukki districts of Kerala. Soil organic carbon stocks (SOC) at the surface (0–30 cm) were higher, 9.10 t C ha−1 and 7.49 k t C ha−1 in forest soils of Chikmagaluru and Idukki, respectively, and the subsurface (30–100 cm) SOC stocks were higher in the coffee plantation ecosystems, 9.11, 9.87, and 8.41 t C ha−1, respectively, in Chikmagaluru, Wayanad, and Idukki. Vulnerability analysis revealed that Chikmagaluru forest (0.57) and coffee (0.51), Wayanad forest (0.58) and coffee (0.55) land uses were low, and both the land uses in Idukki were medium in the status of land degradation with scores of 0.65 and 0.60, respectively, in forest and coffee ecosystems. The difference in the status of land degradation was mainly because of changes in soil reaction, surface, and subsurface SOC stock. An increase in soil pH, CEC, and available nutrients upon conversion to coffee plantation along with increased subsurface carbon storage have confirmed the restorative properties of coffee land use even after conversion from natural forests. [ABSTRACT FROM AUTHOR]

Leaf nutrient content (nitrogen, phosphorus) and their stoichiometric ratio (N/P) as key functional traits can reflect plant survival strategies and predict ecosystem productivity responses to environmental changes. Previous research on leaf nutrient traits has primarily focused on the species level with limited spatial scale, making it challenging to quantify the variability and influencing factors of forest leaf nutrient traits on a macro scale. This study, based on field surveys and literature collected from 2005 to 2020 on 384 planted forests and 541 natural forests in China, investigates the differences in leaf nutrient traits between forest types (planted forests, natural forests) and their driving factors. Results show that leaf nutrient traits (leaf nitrogen content (LN), leaf phosphorus content (LP), and leaf N/P ratio) of planted forests are significantly higher than those of natural forests (P< 0.05). The impact of climatic and soil factors on the variability of leaf nutrient traits in planted forests is greater than that in natural forests. With increasing forest age, natural forests significantly increase in leaf nitrogen and phosphorus content, with a significant decrease in N/P ratio (P< 0.05). Climatic factors are key environmental factors dominating the spatial variability of leaf nutrient traits. They not only directly affect leaf nutrient traits of planted and natural forest communities but also indirectly through regulation of soil nutrients and stand factors, with their direct effects being more significant than their indirect effects. [ABSTRACT FROM AUTHOR]

Anthropogenic activities carried out by communities around forests in production forests, protected forests, and conservation forests have an impact on changes in the land cover of these areas. This impact is difficult to avoid because, on the other hand, production forests and protected forests are in direct contact with the lives of local communities. Changes in land cover have a significant impact on the contribution of Folu Net Sink, which is set by the government at 31.89% in 2030 with its efforts. This research aims to provide an overview of land cover changes that occurred in natural forests of the Eucalyptus urophylla type from 2002 to 2022. The method used in this research is a supervised/guided digital classification technique. Ground checks were also carried out in this research to match the accuracy of the image data with the actual conditions in the field. The research results show that changes in land cover in 2012 and 2017 were very extreme. Forest fires were the cause of changes in land cover during this period. Meanwhile, in 2002, 2007, and 2022, the land cover was still good, in a positive direction. The causes of changes in land cover are encroachment activities, illegal logging, firewood theft, rice fields, forest fires, plantations, and farming. Forest preservation provides very high benefits for life on earth. Therefore, it is important to pay attention to the welfare of local communities so that they do not damage the forest, as well as increase the capacity to educate the community regarding zoning or blocks in conservation and protected forests. Apart from that, good forest management is needed to ensure forest sustainability in the future. [ABSTRACT FROM AUTHOR]

Abstract Natural forests are crucial for climate change mitigation and adaptation, but deforestation and degradation challenges highly reduce their value. This study evaluates the potential of natural forest carbon stock and the influence of management interventions on enhancing forest carbon storage capacity. Based on forest area cover, a study was conducted in nine purposely selected forest patches across various forest ecosystems. Data on diameter, height, and environmental variables from various forest management approaches were collected and analyzed with R Ver. 4.1. The findings revealed a substantial difference (p .029) in carbon stock between environmental variables and management interventions. The findings revealed a strong connection between environmental variables and the overall pool of carbon stock within forest patches (p .029). Carbon stocks were highest in the Moist‐montane forest ecosystem (778.25 ton/ha), moderate slope (1019.5 ton/ha), lower elevation (614.50 ton/ha), southwest‐facing (800.1 ton/ha) and area exclosures (993.2 ton/ha). Accordingly, natural forests, particularly unmanaged parts, are sensitive to anthropogenic stresses, decreasing their ability to efficiently store carbon. As a result, the study highlighted the importance of sustainable forest management, particularly area exclosures and participatory forest management, in increasing forest carbon storage potential.

Homestead farming has been playing an important role in the livelihood of the ethnic minority groups, including Garo and Koch in Bangladesh. It secures the integrated production of crops, trees and livestock in the premises of household and its surrounding areas. The northwestern hill forest is decreasing day by day at an alarming rate. In the context of the prevailing shortage of fuel wood and excessive deforestation, the existing homestead farming system of the ethnic people needs to be strengthened for their better livelihood. From this point of view, the study was conducted in two villages of Jhenaigati Upazila (the smallest administrative unit of Bangladesh) of Sherpur District of Bangladesh to find out changes of the homestead farming systems and their impact on people's livelihood. Fourteen different homestead farming systems were categorized by the presence of different livestock populations. A total of 109 plant species from 60 families were recorded in the study area. Among them 28 percent were identified as fruit species, 20 percent medicinal, 13 percent vegetable, 10 percent timber, 10 percent ornamental, 5 percent spices and 5 percent fuel wood. Fruit tree species like mango and jackfruit showed dominance. This dominance may be associated with the multipurpose usage of fruit trees as food, fuel wood, fodder and timber. About 20% households replaced their cassava plantation area with a mixed garden of fruits and timber yielding species. Exotic timber yielding species and medicinal plants were grown for commercial purposes as well as daily consumption. About fifty percent households had mixed garden of fruit and timber yielding species. Almost all households planted exotic timber yielding species in their mixed gardens. Medicinal plants were grown commercially, which was not practiced ten years back in the study area. The livestock species found in the homestead were cattle, chicken, duck, pig, goat, sheep and rabbit. Households having large homestead area had a tendency to raise more diversified livestock species. Pig rearing has shown a declining trend due to high price of piglets. [Fundam Appl Agric 2023; 8(4.000): 627-638]

Pinus pinea is an important Mediterranean species due to its adaptability and tolerance to aridity and its high-quality pine nuts. Different forest types located in Mediterranean native and non-native environments provide the opportunity to perform comparative studies on the species’ response to climate change. The aims of this study were to elucidate growth patterns of the species growing in native and exotic habitats and to analyze its response to climatic fluctuations, particularly drought, in both geographical contexts. Understanding stone pine (Pinus pinea) growth responses to climate variability in native and exotic habitats by comparing natural stands and plantations may provide useful information to plan adequate management under climate change. By doing so, we enhance the understanding of P. pinea’s adaptability and provide practical approaches to its sustainable management. In this study, we reconstructed and compared the stem radial growth of seven stone pine stands, two in southern Spain and five in central–southern Chile, growing under different climatic conditions. We quantified the relationships between growth variability and climate variables (total rainfall, mean temperature, and SPEI drought index). Growth was positively correlated with autumn rainfall in plantations and with autumn–winter rainfall in natural stands. Growth was also enhanced by high autumn-to-spring rainfall in the driest Chilean plantation, whereas in the wettest and coolest plantation, such correlation was found in winter and summer. A negative impact of summer temperature was found only in one of the five Chilean plantations and in a Spanish site. The correlation between SPEI and tree-ring width indices showed different patterns between and within countries. Overall, exotic plantations showed lower sensitivity to climate variability than native stands. Therefore, stone pine plantations may be useful to assist in mitigating climate change.

Abstract 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.

Extensive research has explored land use and land cover change (LULCC) in tropical ecosystems, but more detailed carbon footprint data is essential for defining strategies to enhance carbon sinks. This study assessed LULCC and its associated carbon footprints in different natural ecosystems. It also established forest reference levels (FRL). We used Landsat images for supervised classification and conducted forest inventories in 186 plots that span moist semi-deciduous forest, swamp forest, gallery forest, woodland and savannah areas. Biomass calculations employed allometric models, biomass expansion factors, and root-to-shoot ratios. Except in Lama Forest Reserve, anthropogenic pressures led to the regressive conversion of natural forest areas to savannah, croplands, and fallows. A progressive trend was observed in semi-deciduous forest (3.18 % per year), resulting in a positive LULC carbon footprint (16.06 tCO2eq.yr−1ha−1). 41.94 % of typical swamp forest was lost, releasing -62.89 tCO2eq.yr−1ha−1. Similarly, woodland decreased by -1.48 and -5.89 % per year, according to considered site, with emissions of -12.16 and -21.83 tCO2eq.yr−1ha−1, respectively. FRL followed the gradient of canopy cover of the different vegetation types. The results highlight the need for adequate conservation and management, considering land use and cover specifics, and provide useful baselines for REDD+ activities in countries with similar ecosystems.

The analysis of fine and coarse roots’ functional traits has the potential to reveal the performance of the root system, which is pivotal in tree growth, development, and failure in both natural and urban forest ecosystems. Furthermore, root traits may be a powerful indicator of tree resilience mechanisms. However, due to the inherent difficulties in measuring ‘the hidden half,’ and despite the recent advancements, the relationships among root functional traits and biotic and abiotic drivers still suffer from a lack of information. Thus, our study aimed to evidence knowledge milestones and gaps and to categorize, discuss, and suggest future directions for effective experimental designs in fine and coarse root studies. To this end, we conducted a systematic literature review supported by backward manual referencing based on 55 root functional traits and 136 plant species potentially suitable for afforestation and reforestation of natural and urban forest ecosystems. The majority of the 168 papers on fine and coarse root studies selected in our review focused predominantly on European natural contexts for a few plant species, such as Fagus sylvatica, Picea abies, Pinus sylvestris, and Pinus cembra, and root functional traits such as standing biomass, phenology production, turnover rate, and non-structural carbohydrates (NSC). Additionally, the analyzed studies frequently lack information and uniformity in experimental designs, measurements, and statistical analysis, highlighting the difficult integration and comparison of outcomes derived from different experiments and sites. Moreover, no information has been detected in selected literature about urban forest ecosystems, while most of the studies focus on natural forests. These biases observed during our literature analysis led us to give key indications for future experiment designs with fine and coarse roots involved, which may contribute to the building up of common protocols to boost the monitoring, managing, and planning of afforestation and reforestation projects.

The nitrogen (N) enrichment induced by atmospheric N deposition affects both soil physicochemical properties and bacterial communities. However, how N enrichment affects soil aggregate-associated bacterial communities remains largely unclear. In this study, we conducted a two-year N addition experiment (four N levels: 0, 5, 10, and 20 g N m−2 year−1, corresponding to normal N, low N, medium N, and high N, respectively) in a Quercus liaotungensis Koidz–dominated forest. The distribution, nutrient content, and bacterial community composition of the soil aggregates were measured under various N enrichment conditions. N enrichment changed the aggregate distribution, increased the content of nutrients in aggregates, and altered the aggregate-associated bacterial community composition. N enrichment reduced the complexity of the bacterial co-occurrence network and degraded the interactions between bacteria compared with those observed under the normal N level. Aggregate-associated bacterial community was determined to be primarily affected by N enrichment level but not by aggregate size. The litter properties are the key factors affecting the composition of bacteria in aggregates. These findings improve our understanding of aggregate-associated bacterial responses to N enrichment and the related influencing factors. [ABSTRACT FROM AUTHOR]

Felling and skidding are essential in the timber extraction process. But on the other hand, residual stand damage can't be avoided. This study aimed to analyze the impact of conventional and improved felling and skidding techniques on residual stands in natural forests. Three observation plots were developed to identify the types, numbers, and criteria of residual stand damage due to both techniques. The criteria were categorized as a) minor damage (<25%), b) moderate damage (25--50%), and c) major damage (>50%). It showed that the conventional felling and skidding techniques caused damages of 14.92% dominated by tree crown damage and 16.70% dominated by stem wounds, respectively. The residual stand damage due to conventional felling and skidding techniques was 31.62% categorized as medium damage. Meanwhile, improved felling and skidding techniques caused damage of 9.89% dominated by broken trees and 10.27% dominated by stem wounds, respectively. The residual stand damage due to improved felling and skidding technique was 20.16% categorized as minor damage. The improvement techniques can minimize residual stand damage by 36.24%. Therefore, a good understanding of forest concessionaires regarding RIL principles is necessary for achieving sustainable timber harvesting [ABSTRACT FROM AUTHOR]

Birds are one of the best-described taxa, but detailed knowledge about most bird species in Ethiopia remains rare, which hinders the development and evaluation of conservation strategies in the region. In this study, we estimated bird species diversity and abundance in the Suba Forest area (comprising natural forest and adjacent plantation forest and farmland) in central Ethiopia, during the dry and wet seasons in 2021. Bird data were collected using line transects or point counts in each habitat type. Two-way ANOVA was applied to evaluate the effect of habitat and season on bird species richness and abundance. A total of 132 bird species belonging to 51 families were recorded during the study. Of these, 124 are residents, 4 are endemic to Ethiopia, 11 are endemic to Ethiopia and Eritrea, and 4 are near endemics (one largely confined to Ethiopia and the others with their core populations in Ethiopia and Eritrea). Habitat type and season both had significant effects on species abundance and richness. Species diversity was highest in natural forest during the wet season, and lowest in farmland during the dry season. Plantation forest and farmland shared similar avian communities, with both being human-altered habitats in close proximity to each other. Native forest supported the highest number of bird species, which confirms the Suba Forest area's great potential for biodiversity conservation and sustainable wildlife tourism. Continuous monitoring of this area and effective implementation of conservation measures will provide beneficial outcomes for not only avifauna but other taxa. [ABSTRACT FROM AUTHOR]

The presented study estimated the aboveground biomass (AGB) of Pinus roxburghii (chir pine) natural forests and plantations, and created biomass maps using a relationship (regression model) between AGB and Sentinel-2 spectral indices. The mean AGB and BGB (belowground biomass) of natural forests were 79.54 Mg.ha-1 and 20.68 Mg.ha-1, respectively, whereas the mean AGB and BGB of plantations were 94.48 Mg.ha-1 and 24.56 Mg.ha-1, respectively. Correlation showed that mean diameter at breast height (DBH) and mean height have weak relationships with AGB, and BGB has shown correlation coefficients (R2 = 0.46) and (R2 = 0.56) for polynomial models. Regression models between AGB (Mg.ha-1) of Pinus roxburghii natural forest and Sentinel-2 spectral indices showed a strong relationship with Ratio Vegetation Index (RVI) with R2 = 0.72 followed by Normalized Difference Vegetation Index (NDVI) and Atmospherically Resistant Vegetation Index (ARVI) with R2 = 0.70. In contrast, the lower performance of spectral indices has been shown in regression with plantation AGB. Correlation coefficients (R2) were 0.41, 0.41, and 0.40 for RVI, NDVI, and ARVI, respectively. All indices showed that the distribution of AGB data was not the best fit with the linear regression model. Therefore, non-linear exponential and power models were considered the best fit for NDVI, RVI, and ARVI. A biomass map was developed from RVI for both natural forests and plantation because RVI has the highest R2 and lowest P-value.

Ethiopia harbour the Eastern afromontane and Horn of Africa hotspots of biodiversity. The general objective of this study was to investigate the floristic composition and diversity of species, the structure and the regeneration status of the Hurubu forest. Three parallel transects lines with 1 km length were systematically laid across the forest with an interval of 500 m in south to north direction. Thirty sample quadrants of 20 m × 20 m were placed along transects at an interval of 200 m for mature trees and shrubs, while for the purpose of seedling and sapling inventory, four sub-quadrants of 1 m × 1 m were laid at each corner of the main quadrant. A total of 32 woody species representing 25 families were recorded consisting of trees and shrubs. The lower storey consisted of all woody plant species, except Ekebergia capensis tree species. The middle storey consisted about 14.41 % of the tree species while the upper storey involved only 2.35 % of the total individual trees in the forest. The total basal area of woody plants in Hurubu forest was 90 m2 per ha. The three most important woody species with the highest IVI were Juniperus procera, Osyris quadripartite and Myrsine africana in decreasing order. The general regeneration status of the tree species of the study site was satisfactory at the community level showing a ‘fair’ regeneration status. Therefore, special conservation actions should be implemented for the poorly and not regenerating woody species of the forest.

The importance of preventing S. Stenoptera in restoring sustainable forest management to maintain the existence of forests in the future, the reduction due to deforestation causes a decrease in land conventions. Shorea stenoptera Burck is a forest species native to Borneo, Sumatra, Thailand, and Malaysia. IUCN declared this species in the category of Near Threatened. This study aims to analyze the species composition, stand structure, and natural regeneration of Shorea stenoptera Burck and identify the biophysics effect on the regeneration performance of S. stenoptera in KHDTK Haurbentes. This research method uses vegetation analysis by constructing five observation areas. The results showed that S. stenoptera dominated at each growth stage. The stand structure shows an inverted J-curve. This indicates that the stands of S. stenoptera have turned into natural forest. The decrease in density followed the increase in diameter class, so S. stenoptera regeneration showed normal regeneration. Biophysical aspects such as slope and elevation affect the growth of S. Stenoptera by observing the characteristics of the analysis adjusted statistically.

Biomass in forests sequesters substantial amounts of carbon; although the contribution of aboveground biomass has been extensively studied, the contribution of belowground biomass remains understudied. Investigating the forest biomass allocation is crucial for understanding the impacts of global change on carbon allocation and cycling. Moreover, the question of how climate factors affect biomass allocation in natural and planted forests remains unresolved. Here, we addressed this question by collecting data from 384 planted forests and 541 natural forests in China. We evaluated the direct and indirect effects of climate factors on the belowground biomass proportion (BGBP). The average BGBP was 31.09% in natural forests and was significantly higher (38.75%) in planted forests. Furthermore, we observed a significant decrease in BGBP with increasing temperature and precipitation. Climate factors, particularly those affecting soil factors, such as pH, strongly affected the BGBP in natural and planted forests. Based on our results, we propose that future studies should consider the effects of forest type (natural or planted) and soil factors on BGBP. [ABSTRACT FROM AUTHOR]

The importance of preventing Shorea stenoptera in restoring sustainable forest management to maintain the existence of forests in the future, the reduction due to deforestation causes a decrease in land conventions. S. stenoptera Burck is a forest species native to Borneo, Sumatra, Thailand, and Malaysia. IUCN declared this species in the category of Near Threatened. This study aims to analyze the species composition, stand structure, and natural regeneration of S. stenoptera Burck and identify the biophysics effect on the regeneration performance of S. stenoptera in KHDTK Haurbentes. This research method uses vegetation analysis by constructing five observation areas. The results showed that S. stenoptera dominated at each growth stage. The stand structure shows an inverted J-curve. This indicates that the stands of S. stenoptera have turned into natural forest. The decrease in density followed the increase in diameter class, so S. stenoptera regeneration showed normal regeneration. Biophysical aspects such as slope and elevation affect the growth of S. stenoptera by observing the characteristics of the analysis adjusted statistically. [ABSTRACT FROM AUTHOR]

Researchers build growth models to predict the growth of forest stands and propose management measures to improve the overall quality of these stands. In this study, data collected from 91 sample plots from the eighth (2010) and ninth (2015) Chinese National Forest Inventories in Jiangxi Province were used to establish a transition-matrix growth model. Then, 12 potential equilibrium curves were set to guide forest management, and a transition-matrix growth model was used to predict stand growth in Jiangxi Province. In each 10-year management period, trees with diameters that exceeded the equilibrium curve were cut down. The results show that species diversity (H1), size diversity (H2), and basal area (B) have statistically significant influences on growth, mortality, and recruitment. Moreover, the high accuracy of the transition-matrix growth model is demonstrated. According to the simulation results, B = 35 m2/ha, the maximum diameter of retained trees Dmax = 45 cm and the adjacent diameter ratio q = 1.7 constitute the optimal equilibrium curve to guide forest management. The diameter distribution guided by the equilibrium curve is reverse J-shaped and is associated with significant increases in the hardwood stock volume and current annual growth. Under the guidance of the equilibrium curve, the forests in Jiangxi Province can be reasonably managed, produce more high-economic-value timber, and achieve a more stable species composition. This study will help maximize the ecological and economic benefits of forests and provide a reference for the realization of the sustainable development of forestry. Furthermore, the results can be used to improve the facility and accuracy of natural forest harvesting. [ABSTRACT FROM AUTHOR]

To explore the response of functional traits and phylogeny to different gap sizes, simple linear regression was used to study the changes in leaf functional traits and functional diversity with gap size in a Castanopsis kawakami natural forest. Pearson correlation analysis was used to study the correlation between phylogenetic diversity and functional diversity, combined with phylogenetic trees and functional trait trees to determine species adaptation strategies. The results showed that the specific leaf area of C. kawakamii natural forest decreased significantly with increasing canopy openness (P<0.01), the leaf dry matter content decreased significantly with increasing canopy openness (P<0.05), and leaf nitrogen content decreased significantly with increasing canopy openness (P<0.01). Furthermore, the chlorophyll content, leaf thickness, and leaf phosphorus content increased significantly (P<0.05). With increasing canopy openness, the functional evenness, functional divergence, and functional dispersion of C. kawakamii natural forest decreased significantly (P<0.05). However, the functional richness and Rao's quadratic entropy had no pronounced trend. A weak correlation was observed between phylogenetic structure, phylogenetic diversity, and functional diversity in the C. kawakamii natural forest, in which the index of phylogenetic diversity was only significantly positively correlated with functional richness (P<0.01). No significant phylogenetic signals were detected in the leaf functional traits of C. kawakamii natural forest (P>0.05). Many distant species had functional similarity, showing convergence with the external environment. During gap regeneration of C. kawakamii natural forest, plant leaf functional traits showed convergent adaptation, with habitat filtration dominating community construction and species coexistence. [ABSTRACT FROM AUTHOR]

The Corchal "El Mono Hernández" Fauna and Flora Sanctuary is a protected area located in northern Colombia and is home to the Pterocarpus officinalis forest. In this area, however, this forest cover is declining due to natural causes associated with a change in the hydrosedimentological dynamics. Multitemporal assessment was performed to quantify the forest loss. Landsat images from the years 1986, 1998, 2003, 2013, and 2018 were downloaded and a supervised classification was performed using four cover classes: "Pterocarpus officinalis," "other vegetation," "waterbody," and "bare land." The results showed that the vegetation cover of Pterocarpus officinalis forest had an initial extent of 865.26 ha in 1986; for the 1986–1998 period, the reduction was 60.30 ha; for the 1998–2003 period, it was 399.15 ha; and for the 2003–2013 period, it was 78.30 ha. Contrary to previous periods, in the 2013–2018 period, 79.65 ha of forest was recovered. In conclusion, Pterocarpus officinalis forest lost approximately 50% of its cover during the 1986–2018 period. This information is of great importance for government and management entities for decision-making in the conservation and restoration of this forest. [ABSTRACT FROM AUTHOR]

In order to explore the structural changes of forest land after selective cutting and provide a basis for the restoration of important species such as Larix sibirica, 2 different types of communities of natural forest in Berqin area in Altai mountain were took as materials. The important value method and diameter class distribution method were used to study the species composition, diameter class structure in the arbor layer, the composition, number and height characteristics of renewed seedlings after the Larix sibirica had been felled. The investigated of the plot showed that Larix sibirica was the dominant species in 2 communities before felling. The important value of Picea obovata in height thinning (ZT) was 65.30, which was absolutely dominant, and the imporatnt value of Larix sibirica in height thinning (HT) ranking first with 56.70 in community I. Abies sibirica had the largest important value for 61.05 in community II after 30 years selective felling. With the increased of cutting intensity, the diameter distribution of trees shifted to a larger diameter class, small-diameter grades accounted for 77.80% in LT and the number of large-diameter trees accounted for 64.80% in HT. The regeneration characteristics of different community types were different after selective felling. Picea obovata seedlings accounted for 61.00% of light thinning and 77.00% of height thinning for community I, with the increased of cutting intensity, Larix sibirica seedlings significantly increased. The seedling height level of light thinning was concentrated in <30 cm, while it was mainly concentrated in 30-60 cm for height thinning. Abies sibirica seedlings accounted for the vast majority for 92.00% but Picea obovata seedlings accounted for merely in community II. Generally speaking, after selective felling, the regeneration ability of Abies sibirica and Picea obovata were stronger than that of Larix sibirica, and gradually replaced Larix sibirica as the predominant species; the higher the intensity of selective cutting, the better effects of natural regeneration of Larix sibirica. It was suggested that sufficient light conditions might be needed for natural regeneration. [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 use of light detection and ranging (LiDAR) for investigating forest parameters has gained attention in recent years. However, the occlusion of trees in natural forests makes it difficult for LiDAR on a single platform to capture complete point clouds of trees. In order to solve this problem, it is crucial to combine multi-platform LiDAR data. Because of the complexity of natural forests and the small difference between the geometric characteristics of trees, current multi-platform LiDAR data fusion remains an ongoing challenge in natural forests. In this paper, an automatic registration framework for multi-platform point cloud data in natural forests based on tree distribution pattern was proposed. It consists of five steps, namely segmenting trees, generating feature descriptors, matching trees and registering coarsely and finely. The proposed registration framework can determine the same and accurate location information of matching trees from multi-platform LiDAR data, and a large number of correct matching trees can be obtained through two rounds of a single tree matching process. The proposed framework was validated by fusing airborne laser scanner (ALS) and backpack laser scanner (BLS) data in natural forest. According to experimental results, the proposed framework has a high registration accuracy (root-mean-square error (RMSE) = 0.133 m, mean absolute error (MAE) = 0.126 m). In addition, when the single tree segmentation accuracy exceeds 0.85, the proposed framework is less affected by segmentation errors. In natural forests, the proposed framework can effectively improve the accuracy and efficiency of multi-platform LiDAR data registration. [ABSTRACT FROM AUTHOR]

The Grain-for-Green Program in China is one of the largest payments for ecosystem services programs, and it is regarded as effective for protecting the ecological environment and mitigating disasters. However, research into the effects of revegetation on seed dispersal as an ecosystem service remains limited. Thus, we compared the effects of different types of vegetation restoration (i.e., natural forest (NF), Grain-for-Green forest (GG), and abandoned cropland (AC)) in the Taihang Mountains on the rodent abundance, seed dispersal, and seedling recruitment in Quercus variabilis forest and the pathways involved. The results showed that NF and GG clearly had similar effects on the rodent composition and abundance, but the seed removal rate, seed dispersal distance, and scatter-hoarded proportion were higher under GG than AC, thereby indicating that GG may provide a similar seed dispersal service compared to NF. By contrast, the scatter-hoarding acorn proportions and dispersal distance were significantly lower under AC than NF. Therefore, GG stands could supply an equivalent seed dispersal service to NF, as well as increasing the rodent composition and abundance, and improving the seed dispersal services and capacity for plant movement, thereby contributing to accelerated vegetation restoration at the landscape scale, with significant implications for conserving biodiversity.

Outbreaks of defoliator insects are important natural disturbances in boreal forests, but their increasing frequency under warming climate conditions is of concern. Outbreak events can shape ecosystem dynamics with cascading effects through trophic networks. Caterpillar defoliation can alter tree physiology, increase sunlight to the understory, and result in the deposition of large amounts of leaf litter and caterpillar frass to the forest floor. These modifications can thus affect soil organisms through direct (e.g., changes in soil temperature or moisture) or indirect (e.g., changes in detrital and root food webs) mechanisms. We assessed whether a recent (2015 to 2017) outbreak of the forest tent caterpillar (Malacosoma disstria) at the Lake Duparquet Teaching and Research Forest (Abitibi, QC, Canada) affected soil springtail communities, abundant microarthropods in forest soils. In 2018 and 2019, we sampled litter and soil (0–10 cm depth) at eight sites each in aspen-dominated (Populus tremuloides Michx) stands that were undefoliated or had a recent defoliation history. We found no significant difference in springtail abundance (specimens cm−2) or alpha diversity indices between undefoliated sites and those with defoliation history. However, we observed a transient change in springtail community composition 1 year after the outbreak (2018) with the absence of Folsomia nivalis, Anurophorus sp1, and Xenylla christianseni in sites with defoliation history, but no compositional differences were observed in 2019. Certain soil nutrients (P, C, Mg, Mn) were significant predictors of springtail community composition, but soil microbial biomass was not, despite its significant decrease in sites with defoliation history. Our results show that soil springtail communities respond in the short-term to the forest tent caterpillar outbreak with compositional shifts, but seem ultimately resilient to these events. [ABSTRACT FROM AUTHOR]