Structure Of Forest Ecosystems Research Articles

Divergent responses of forest canopy height to environmental conditions across China

As major components of terrestrial ecosystems, forest ecosystems play an important role in sequestering carbon and hence mitigating climate change. Canopy height is a crucial factor characterizing the structure and function of forest ecosystems, yet the driving mechanism of forest canopy height receives less attentions in China. Here, we utilize the satellite-based forest canopy height product with several environmental and climate factors (e.g. forest age, temperature, etc.) to delineate the spatial distributions of forest canopy height and its drivers in China at 1 km spatial resolution during the period of 2014 to 2018. The random forest is employed for identifying the dominant factors at province level, while Shapley additive explanations (SHAP) analysis is further incorporated at pixel-level to dig into the specific contributions of each driver. The results show that forest age primarily dominates the spatial distributions of forest canopy height across different forest ecosystems of China, followed by mean annual precipitation, soil type, and aspect. SHAP analysis further indicates that other factors, such as soil moisture and wind speed, also play critical roles to shape the spatial patterns of forest canopy height in China, which could not be revealed from province-level random forest analyses. Such results emphasize the priority of incorporating SHAP analysis with random forest to advance our understanding of forest canopy height distributions and benefit future projections. Our study highlights the necessity to characterize the spatial heterogeneity of forest canopy height, which is critical for accurate estimations of forest and even terrestrial carbon sink in China, facilitating the achievement of the goal of “carbon peak in 2030 and carbon neutrality in 2060”.

Application of Bayesian Causal Inference in the Study of the Relationship Between Biodiversity and Aboveground Biomass of Subtropical Forest in Eastern China

The relationship between biodiversity and ecosystem function is crucial for understanding the structure and processes of subtropical forest ecosystems. However, the extent to which biodiversity influences subtropical forest biomass remains unclear. This study applies Bayesian causal inference to explore causal relationships between forest Aboveground Biomass (AGB) and its potential driving factors (biodiversity factors, biotic factors and abiotic factors) based on Huangshan Forest Dynamics Plots. Furthermore, hypothetical interventions are introduced to these driving factors within the causal network to estimate their potential impact on AGB. The causal relationship network reveals that species diversity and functional diversity are the most direct factors influencing AGB, whereas phylogenetic diversity exerts only an indirect effect. Biotic and abiotic factors also contribute indirect effects on AGB, potentially by influencing other mediating indexes. Intervention analysis shows that with low-level interventions on direct influencing factors, the probability of low AGB is as high as 84%. As the intervention level increases to high, the probability of low AGB decreases by 36%. Moreover, AGB demonstrates a particularly sensitive response to changes in Rao’s quadratic entropy (RaoQ) intervention levels, more so than to other factors, highlighting its critical role in maintaining forest biomass. Therefore, we contend that functional diversity, due to its direct reflection of species’ roles in ecosystem processes, is a more accurate measure of the impact of biodiversity on biomass compared to species or phylogenetic diversity and the interplay between abiotic and biotic factors and biodiversity should not be overlooked. This approach offers a powerful tool for exploring causal relationships, thereby providing a more nuanced and accurate understanding of the relationship between biodiversity and forest ecosystem function.

Repeated Tree Inventories of Pine Forests in South Florida's Big Cypress National Preserve.

The natural forest ecosystems of South Florida, USA, support a high biodiversity of plant and animal species and provide valuable ecosystem services. However, these ecosystems remain poorly represented in global studies, primarily due to a paucity of standardized data. Here, we present previously unpublished data from 332 censuses of 54 permanent 1-ha tree inventory plots in the Racoon Point area of Big Cypress National Preserve, Florida, USA, including a total of nearly 100,000 measurements (diameter or height) of > 17,000 individual living trees and palms (with additional measurements of nearly 6000 dead pine snags) collected sporadically over a 19-year period (1993-2012). These data, which were originally collected as part of a project to investigate tree responses to different experimental burning regimes, provide unique insight into the diversity, composition, structure, and dynamics of South Florida's unique and endangered pine forest ecosystems. Data files include the species identity, size (dbh = diameter at breast height), and location of all trees ≥ 5 cm dbh in 54 individual tree plots. Additional data are provided about heights of palm trees, and the location and burn history of each plot. These data are freely available for noncommercial scientific use under a Creative Commons license; users are encouraged to cite this paper when using the data.

Diversity of Birch and Alder Forests in the Kostanay Region of Kazakhstan

This study delves into the phytocenotic structure and biodiversity of forest ecosystems dominated by species of the family Betulaceae (Betula pendula, Betula pubescens, and Alnus glutinosa) in the Kostanay region of Kazakhstan. The research is a significant step toward understanding the influence of environmental factors, particularly hydrological regimes and soil conditions, on the formation and functioning of these forest communities. Field studies were conducted across multiple plots, where detailed geobotanical descriptions and analyses of species diversity were performed. The results underscore the significant species diversity, with 146 vascular plant species identified across various forest types, and are of great importance. Birch forests exhibit higher species diversity than alder forests, with the highest diversity observed in plots with favourable moisture conditions. The study concludes that the hydrological regime is critical in shaping these forest ecosystems’ phytocenotic structure and productivity. These conclusions underline the importance of biodiversity conservation and sustainable forest management in the region, making the implications of this research significant and far reaching.

Identifying habitat modification by Chinese pangolin in subtropical forests of southern China.

The excavation of Chinese pangolin (Manis pentadactyla) is expected to alter habitat heterogeneity and thus affect the functioning and structure of forest ecosystems. In this study, the bioturbation of Chinese pangolin on forest soils in three regions (Heping, Tianjingshan, and Wuqinzhang) across Guangdong province was quantified. Overall, a mean of 2.66 m3·ha-1 and 83.1 m2·ha-1 of burrows and bare mounds, respectively, was excavated by Chinese pangolin; the disturbed soils had significantly lower water content and P, C, available N concentrations, but higher bulk density, pH, and microbial abundance than those undisturbed soils. The unevenness of habitat heterogeneity improvement was mainly ascribed to the stronger soil disturbance caused in resting burrows by pangolins. Patterns of altering habitat heterogeneity were site-specific, with high-intensity soil disturbance occurring most in shrubs, meadows, steep habitats at high elevations, and mountain tops in Heping, while in broad-leaved, coniferous andmixed coniferous and broad-leaved forests away from human settlements in Tianjingshan and upper mountains at high elevations far away from roads and human settlements in Wuqinzhang. Road networks are the main interference for the burrow distribution in Heping and Wuqinzhang and should be programmed.

Understanding Disturbance Regimes From Patterns in Modeled Forest Biomass

AbstractNatural and anthropogenic disturbances are important drivers of tree mortality, shaping the structure, composition, and biomass distribution of forest ecosystems. Differences in disturbance regimes, characterized by the frequency, extent, and intensity of disturbance events, result in structurally different landscapes. In this study, we design a model‐based experiment to investigate the links between disturbance regimes and spatial biomass patterns. First, the effects of disturbance events on biomass patterns are simulated using a simple dynamic carbon cycle model based on different disturbance regime attributes, which are characterized via three parameters: μ (probability scale), α (clustering degree), and β (intensity slope). 856,800 dynamically stable biomass patterns were then simulated using combined disturbance regime, primary productivity, and background mortality. As independent variables, we use biomass synthesis statistics from simulated biomass patterns to retrieve three disturbance regime parameters. Results show confident inversion of all three “true” disturbance parameters, with Nash‐Sutcliffe efficiency of 94.8% for μ, 94.9% for α, and 97.1% for β. Biomass histogram statistics primarily dominate the prediction of μ and β, while texture features have a more substantial influence on α. Overall, these results demonstrate the association between biomass patterns and disturbance regimes. Given the increasing availability of Earth observation of biomass, our findings open a new avenue to understand better and parameterize disturbance regimes and their links with vegetation dynamics under climate change. Ultimately, at a large scale, this approach would improve our current understanding of controls and feedback at the biosphere‐atmosphere interface in the present Earth system models.

Interruption after Short-Term Nitrogen Additions Improves Ecological Stability of Larix olgensis Forest Soil by Affecting Bacterial Communities.

Atmospheric nitrogen deposition can alter soil microbial communities and further impact the structure and function of forest ecosystems. However, most studies are focused on positive or negative effects after nitrogen addition, and few studies pay attention to its interruption. In order to investigate whether interruption after different levels of short-term N additions still benefit soil health, we conducted a 2-year interruption after a 4-year short-term nitrogen addition (10 and 20 kg N·hm-2·yr-1) experiment; then, we compared soil microbial diversity and structure and analyzed soil physicochemical properties and their correlations before and after the interruption in Larix olgensis forest soil in northeast China. The results showed that soil ecological stabilization of Larix olgensis forest further improved after the interruption compared to pre-interruption. The TN, C:P, N:P, and C:N:P ratios increased significantly regardless of the previous nitrogen addition concentration, and soil nutrient cycling was further promoted. The relative abundance of the original beneficial microbial taxa Gemmatimonas, Sphingomonas, and Pseudolabrys increased; new beneficial bacteria Ellin6067, Massilia, Solirubrobacter, and Bradyrhizobium appeared, and the species of beneficial soil microorganisms were further improved. The results of this study elucidated the dynamics of the bacterial community before and after the interruption of short-term nitrogen addition and could provide data support and a reference basis for forest ecosystem restoration strategies and management under the background of global nitrogen deposition.

Geographical Peculiarities of Pinus sibirica Du Tour Natural Regeneration as Related to its Seed Crops

Forest ecology faces a significant challenge in understanding the dynamics of populations of forest-forming trees during their renewal phase, as it shapes the subsequent development and structure of forest ecosystems. The forest regeneration process relies on the dynamics of the seed yield of the woody plants and the unique characteristics of their distribution. In the case of the Cembrae sp. five-needled pines belonging, which have wingless seeds, their renewal is closely linked to the activities of Nucifraga sp. birds that scatter the seeds to create food reserves in the soil. This research aims to explore the geographical variations of Siberian stone pine (Pinus sibirica Du Tour) natural regeneration as a function of seed abundance. This study was conducted in three Russian mountain regions known for their forests predominated by Pinus sibirica: the Aldan Highlands, the Northern Urals, and the Khamar-Daban Mountains. It was discovered that each region exhibited distinct patterns in both cone yields and Pinus sibirica regeneration. The fluctuations in the thin-billed nutcracker (Nucifraga caryocatactes macrorhynchos Brehm C. L.) populations during the seed harvest season, influenced by the nature of the seed production dynamics in each region, we believed to play a major role in the quantity of Pinus sibirica seedlings appearing in the subsequent year. These findings explain the observed variations in the renewal dynamics of annual emergent seedlings of Pinus sibirica and its reliance on cone yield in the examined regions.

Legal regulation of the use of forest resources

The purpose of the study was to carry out a comprehensive analysis of the legislative framework in the field of forest resource management in Albania in the context of forest ecology, and species diversity, and to identify the main problems and prospects for sustainable development of the country’s forestry. The research methodology included the analysis of statistical data from the National Institute of Statistics of Albania on the structure of forest ecosystems and forms of their management. The results of studies conducted by international organizations such as the World Bank, Global Environment Facility, and Oikon d.o.o. were also used. The structure and composition of Albania’s forest resources, including those of natural and semi-natural origin, are analysed. The legal framework in the field of forest management in Albania is summarized. Different management structures for forestry land are characterized, with the identification of the specifics of use for different forms of ownership. The main problems of forest management are identified, including intensive exploitation of private forests, lack of subsidies and investments, as well as imperfect legislative regulation. Adaptation measures to increase the sustainability of Albania’s forests within the framework of the Albanian Forest Policy Document for the period 2019-2030 are substantiated. Strategic areas of development, such as the expansion of protected areas, the development of ecotourism and the attraction of green investments, are proposed. The study also emphasizes the importance of international cooperation for financial and technical support, which will facilitate the implementation of sustainable forest management practices and biodiversity conservation. The practical significance of the study is that these results can be used to develop strategic directions for the development of the forest sector in Albania, aimed at ensuring sustainable management and conservation of forest resources, which is a key factor for the country’s economic and environmental well-being

Warming-driven increased synchrony of tree growth across the southernmost part of the Asian boreal forests

Climate change has profoundly affected the synchrony of tree growth at multiple scales, thereby altering the structure and function of forest ecosystems. The Asian boreal forests extend southward to the Greater Khingan Range in northeast China. Given the ecological importance and susceptibility to climate change, the impacts of warming on this marginal forest community have been extensively investigated. Nonetheless, how tree growth synchrony changes across this region remains less understood. Focusing on this knowledge gap, we compiled a contiguously-distributed tree-ring network, containing 18 sampling populations and 475 individual larch trees, to explore the changes in multiple-scale growth synchrony across this region. We found increasing growth synchrony at both the individual and population levels over the past decades. The increasing trend of the regional inter-population growth synchrony was well in line with the increasing temperature and PDSI. Furthermore, 11 of the 18 sampling populations showed significant increases in their intra-population growth synchrony. We further associated the sliding intra-population growth synchrony with local climates. Intra-population growth synchrony of 13 and 11 sampling populations were significantly positively correlated with local temperature, and negatively correlated with local PDSI, respectively, demonstrating the driving role of warming-induced drought on growth synchrony. The linear regression model quantifying this relationship suggested that an increase of 1 °C in annual mean temperature would drive the intra-population growth synchrony to increase by 0.047. As warming trends in the study area are projected to continue over this century, our study warns of the further consequences of the increasing growth synchrony may have on the functioning, resilience, and persistence of forests.

Patterns of forest community diversity, regeneration potential and carbon storages along an altitudinal gradient in Eastern Himalaya, India

This study showed changing patterns in the plant species composition, diversity, and carbon storage potential of different forests along altitudinal gradients (i.e. 100 – 1900 m) in Eastern Himalayan India. Different tree, shrub and herb species were sampled along the altitudinal gradients ranging from tropical to temperate forests through Nested Plot design. In each forest, vegetation sampling was made by establishing a permanent plot of 250 m × 250 m as per ISRO-GBP/NCP-VCP protocol. Individuals of trees ≥10 cm girth at breast height (GBH), shrubs and herbs were recorded in 4, 8 and 16 subplots of 31.62 m × 31.62 m, 5 m × 5 m and 1 m × 1 m, respectively. Community attributes such as species richness, density, basal area, diversity indices and biomass and carbon storages were computed for each study site. A total of 5 forest communities (2 each from tropical and subtropical and one from temperate forest) were identified. The woody species diversity was highest in the subtropical forest followed by tropical and temperate forest. Altitude played an important role in the Eastern Himalayan Mountains in the establishment and distribution of forest community. Forest community composition changes with elevation, for instance, the dominant communities like Dipterocarpus retusus–Phoebe goalparensis–Schima wallichii (D-P-S), Gmelina arborea–Schima wallichii-Duabanga grandiflora (G-S-D), Schima wallichii–Duabanga grandiflora–Alstonia scholaris (S-D-A), Alstonia scholaris–Terminalia myriocarpa–Bischofia javanica (A-T-B) and Acer thomsonii–Rhodendron arboreum–Quercus lamellose (A-R-Q) were present at elevational ranges of 100–300 m, 300–700 m, 700–1100 m, 1100–1500 m and 1500–1900 m, respectively. The study showed that about 41–57% of the tree species exhibited good regeneration followed by 23–30% as fair, 6–16% as poor, and 6–21% species did not show regeneration along the altitudinal gradient. The total biomass carbon (Mg C ha−1) varied from 84.74 to 163.56 in tropical, 103.12 – 156.41 in subtropical and 133.05 in temperate forest. In conclusion, community composition, regeneration pattern and biomass carbon storage changes along altitude because of altered biophysical characteristics. However, despite variations in elevation, factors for forest disturbance at different altitudes significantly contributed to the community attributes and overall accumulation of biomass carbon. Hence, the traditional management practices carried out by local communities also play a crucial role in shaping the structure, composition, and carbon dynamics of forest ecosystems. Understanding the impacts of these practices is essential for promoting sustainable forest management by conserving forests and preserving carbon stocks for mitigating climate change in future. This study emphasizes the importance of long-term forest monitoring to promote biodiversity conservation and formulate conservation strategies that support sustainable forest management policies to which ensure continuous provision of ecosystem services in the region.

The Short-Term Responses of Forest Soil Invertebrate Communities to Typhoon Disturbances

Knowledge regarding the response of soil invertebrate communities to typhoon disturbance is limited, although it is known that soil invertebrates are sensitive to forest disturbances and that tropical cyclones (typhoons/hurricanes) are the most destructive natural disasters affecting the structure and function of forest ecosystems. To fill this knowledge gap, soil invertebrates in both litter and topsoil layers were investigated in four representative subtropical coastal forests of eastern China one week before the first typhoon (Hinnamnor) (T1), one day after the first typhoon (Hinnamnor) (T2), one day after the second typhoon (Muifa) (T3), and one week after the second typhoon (Muifa) (T4) in September 2022. Typhoon disturbances decreased the density and taxa abundance of soil invertebrate communities in litter layer, but the first typhoon disturbance increased these values in the topsoil layer. One week after the second typhoon disturbance, soil invertebrate communities in the litter layer showed a gradual recovery trend. Meanwhile, the soil invertebrate communities in the litter layer were more sensitive to typhoon disturbances than those in the topsoil layer. Furthermore, the responses of the soil invertebrate communities to the typhoon disturbances varied greatly with the forest types. The invertebrate densities in the litter layer decreased by 62.1%, 63.53%, 47.01%, and 46.92% in Chinese fir, second broad-leaved, mixed, and bamboo forests, respectively. Particularly, these two non-catastrophic typhoons significantly altered the functional group composition of detrital food webs in the short term, and the proportion of phytophages in detrital food webs in the litter layer increased after the typhoon disturbances. In conclusion, the effects of typhoon disturbances on soil invertebrate communities vary greatly with forest type and soil layer, and soil invertebrate communities can gradually recover after typhoon disturbances. The legacy effects of typhoon disturbances on the functional group composition of detrital food webs may influence carbon and nutrient cycling in forest ecosystems.

Sub-meter tree height mapping of California using aerial images and LiDAR-informed U-Net model

Tree canopy height is one of the most important indicators of forest biomass, productivity, and ecosystem structure, but it is challenging to measure accurately from the ground and from space. Here, we used a U-Net model adapted for regression to map the canopy height of all trees in the state of California with very high-resolution aerial imagery 0.6 m from the USDA-NAIP program. The U-Net model was trained using canopy height models computed from aerial LiDAR data as a reference, along with corresponding RGB-NIR NAIP images collected in 2020. We evaluated the performance of the deep-learning model using 42 independent 1 km2 areas across various forest types and landscape variations in California. Our predictions of tree heights exhibited a mean error of 2.9 m and showed relatively low systematic bias across the entire range of tree heights present in California. In 2020, trees taller than 5 m covered ∼ 19.3% of California. Our model successfully estimated canopy heights up to 50 m without saturation, outperforming existing canopy height products from global models. The approach we used allowed for the reconstruction of the three-dimensional structure of individual trees as observed from nadir-looking optical airborne imagery, suggesting a relatively robust estimation and mapping capability, even in the presence of image distortion. These findings demonstrate the potential of large-scale mapping and monitoring of tree height, as well as potential biomass estimation, using NAIP imagery.

Tree species composition affects litter eco‐hydrological function in Pinus massoniana conifer‐broadleaf mixed forest stands in southwest China

AbstractAlthough changes in tree species composition profoundly affect the structure, function, and processes of mixed forest ecosystems, there is limited knowledge on the effects of these changes on the hydrological functions of the litter layer in Pinus massoniana conifer‐broadleaf mixed forests in subtropical mountains. Here, we investigated three typical P. massoniana forest stands in southwest China: P. massoniana‐Liquidambar formosana conifer‐deciduous broadleaf mixed forest (Pm + Lf), P. massoniana‐Castanopsis eyrei conifer‐evergreen broadleaf mixed forest (Pm + Ce), and P. massoniana plantation (Pm), and conducted field investigations (litter composition and mass) and indoor immersion experiments to analyse the litter water‐holding capacity (LWHC) of forest stands in their natural state and with artificial ratios combining mixed (needle‐leaf and broad‐leaf) litters. The total litter mass did not significantly differ among the three forest stands (p > 0.05), but significant differences were observed in the needle‐leaf (0.67–2.92 t hm−2), broad‐leaf (0.32–1.89 t hm−2) and bark (0.11–0.34 t hm−2) masses in the undecomposed layer. The LWHC of different stand types was in the order of Pm + Lf > Pm + Ce > Pm. The maximum water‐holding capacity of different artificial ratios of mixed litters was positively proportional to the broad‐leaf mass and inversely proportional to the needle‐leaf mass, and the P. massoniana‐L. formosana mixed litter had a higher maximum water‐holding capacity than the P. massoniana‐C. eyrei mixed litter. The LWHC of mixed forests is mainly influenced by stand structure (tree composition) and litter characteristics, and is positively correlated with leaf area, thickness, dry matter content, and surface roughness. This study revealed that the LWHC can be significantly affected by different P. massoniana stands in subtropical mountains. This study will aid the sustainable and ecological management of forest in subtropical mountains, and P. massoniana plantations should be gradually converted into mixed conifer‐broadleaf forests with greater LWHC and buffering capacity.

Seasonal variations in the mechanisms of understory herb diversity in a temperate forest in Northeast China

Herbaceous plants contribute greatly to plant diversity and play an important role in regulating the structure and functioning of forest ecosystems. Comparing with woody species, herbs exhibit higher sensitivity to seasonal changes from spring-growth to autumn-mortality. Despite extensive research on understory herb diversity (e.g., abundance and richness) in forests, how the underlying mechanisms change across seasons remain unclear, especially in temperate forests. We explored the seasonal dynamics of herb diversity (here abundance and richness) by surveying herbs of 174 quadrats (1 m × 1 m) in a 25-ha (500 m × 500 m) temperate forest in spring, summer, and autumn of 2022, respectively. We examined the effects of overstory trees (diversity, composition, and three-dimensional (3D) structural complexity detected by LiDAR), topography (elevation, slope, and aspect), and microsite conditions (light availability, soil nutrients, and soil water content) on herb diversity in different seasons. We found a similar seasonal pattern for herb abundance and richness, i.e., both decreased from spring to summer and then to autumn, but the driving mechanisms differed remarkably across seasons. Specifically, the importance of overstory trees, topography, and microsite conditions on herb abundance vs. richness varied inversely across seasons. For herb abundance, the importance of overstory trees (primarily 3D structural complexity) increased from spring to autumn, while the importance of topography decreased. Conversely, for herb richness, the importance of overstory trees decreased from spring to autumn, while the importance of topography increased. Microsite conditions governed spatial variations of herb abundance in all seasons but only in autumn for herb richness, with importance of soil nutrients remaining relatively constant while that of soil water content and light availability changed greatly across seasons. Our results demonstrate substantial seasonal variations in driving mechanisms of herb diversity in the temperate forest. These differentiated responses of herb abundance and richness to different drivers across seasons further highlight the significance of considering seasonal variations of the mechanisms underlying understory plant diversity in forest biodiversity conservation.

A novel framework for identifying causes of forest fire events using environmental and temporal characteristics of the ignition point in fire footprint

BackgroundForest fire is a very common natural or human-made disaster, which not only burns precious forest resources, but also further alters the forest ecosystem structure and functions as well as global climate. Accordingly, effective information extraction, data management, and modeling of historical fire events are imperative for forecasting and mitigating the onset and progression of forest fires. Traditional remote sensing-based forest fire detection and risk prediction operate at the pixel scale, overlooking the integrity of fire behaviour. Moreover, fire cause records typically stem from ground reports, not fully leveraging the advantages of high temporal resolution thermal infrared remote sensing products. MethodsWe proposed a framework to identify the causes of forest fire events, experimenting with fire incidents from 2001 to 2020 in the Daxing'anling region of Northeast China. Initially, the Jenk-DBSCAN model was employed to acquire fire footprints representative of forest fire events from MODIS MCD64A1 product, and footprint-based fire event attribute information such as ignition locations and timings. Fire footprints matching ground surveys were subsequently filtered, and corresponding environmental variable datasets (including meteorological, topographical, fuel, and human activity factors) were derived in consideration of the spatio-temporal differences of footprint origin and center points. Finally, the optimal variable combinations of the two datasets were fed to three binary classification models including Random Forest (RF), Logistic Regression (LR), and Support Vector Machine (SVM) respectively to identify natural fires or human-induced fires, followed by assessing the accuracy of the fire cause identification models. ResultsResults revealed that there was a high spatio-temporal consistency of those matched fire footprints between the model-extracted and the ground-recorded fire events, evidenced by an overall R2 of 0.87 derived from their area validation. The ignition dates extracted from fire footprints often preceded those reported by local agencies. Among all the selected variable combinations for fire cause identification, the meteorological variables dominated, with daily mean dew point (DEWP) and daily mean visibility (VISIB) being preferentially selected by most models. Across the six models, the model training AUC values were almost greater than 0.8, with the LR model demonstrating superior validation accuracy over RF and SVM. Notably, the accuracy of the LR model using the origin point based dataset surpassed that of the center point-based dataset. The best model achieved an overall accuracy of 90.48%, with the user’s accuracies for human-made fire and natural fire being at 92.86% and 85.71%, respectively. ConclusionsThe proposed framework offers a reliable method for enriching attribute information in forest fire management databases. The resulting fire footprints and origin points can assist in better characterizing the progression of forest fire events. Such endeavours help devise targeted forest fire prevention regulations, fostering sustainable forest management.

The influence of agroforestry on the formation of the structure of forest ecosystems

The functional load of forests necessitates the activation of meliorative measures to optimize the functioning of agrolandscape complexes. These measures contribute to improving the environmental situation and advancing towards sustainable functioning of forest ecosystems. Therefore, the study of the structural and species formation of forest ecosystems is of significant scientific interest. The aim of the article was to analyse the impact of agroforestry measures on the process of forming the structure of forest ecosystems through a comprehensive examination of interrelationships. The research utilized general scientific methods, including specification, deduction, systemic analysis, synthesis, and abstraction, as well as formalization. During the study, vectors of organizing optimized systems of protective forest plantations were analysed, and environmental protection priorities for the development of agroforestry ecosystems were substantiated. Basic principles of managing the agroforestry complex based on sustainable land use were identified, including a comprehensive approach, ecologization of the process, and continuous monitoring. The study revealed current ecological consequences of irrational melioration for forest plantations, such as increased erosion processes and land resource degradation. Risks and challenges requiring preventive solutions were identified. It was proven that increasing the share of agroforestry plantations would allow optimizing the environmental situation in Ukraine, promoting the regeneration of the natural resource base, restoring landscapes, and minimizing land resource degradation processes. The article proposed key measures to optimize the environmental situation at the local level of forest ecosystems, as well as preventive measures to prevent destructive impacts, including the improvement of legal support and the implementation of strict measures of responsibility for irrational resource use. The value of the conclusions lies in their practical application for monitoring the state and the process of forming the structure of forest ecosystems under the influence of agroforestry measures. They also contribute to the effective development of preventive and regenerative protective measures and the formation of balanced forest ecosystems

Использование лесных ресурсов и организация лес- ного хозяйства в Северном Предуралье во второй половине XIX ‒ начале XX века

Forestry practices, including large-scale logging, have led to substantial and long-term alterations in the structure and composition of forest ecosystems. To understand the extent of these changes and identify remaining intact forests, a comprehensive land-use history is crucial. This helps reconstruct and identificate previous impacts, considering their magnitude and extent. Based on archival documents introduced into scholar discussions for the first time, the paper offers a precise comprehension of the extent of forestry growth and the organization of state forestry in the Northern Ural region. The study area covers the basins of the Kolva, a tributary of the Kama, which flows into the Caspian Sea, and the Upper Pechora, which flows into the Arctic Ocean. During the 19th century, this area had a sparse population and no road network. Today, it is a large, intact forest, with a portion designated as a UNESCO World Heritage Site called 'Virgin Forests of the Komi'. The governance of the forest has undergone several changes. In the 1840s, the Cherdynsky district Estate was established in the Cherdyn municipality, covering an area of over 2.8 million hectares. In 1870, the region was split into Cherdynsky and Kolvinsky forest management departments. In 1894, the Kolvinsky district was again separated into three: Kolvinsky, Chusovsky, and Verkh-Pechersky departments. The forests in the Pechora River basin were appealing for foreign export markets. However, logging did not commence due to various reasons. The primary consumers of forest resources were the local inhabitants, who actively constructed boats of various sizes. For example, in 1876, around 1,800 trees of different sizes were cut down to build 15 vessels. The collection of construction timber annually in the 1880s did not surpass 10,000 trees. During the latter half of the 19th century, the mass logging of trees might have begun in the upper Pechora region. This was evidenced by the leasing of vast forested areas in the late 1890s by the Alfred Lidbeck’s Swedish company, with intentions to cut down approximately 2 million construction trees. Nevertheless, logging was not initiated due to the challenge of timber floating and the inadequacy of the workforce. During the same period, a metallurgical plant was established on a tributary of the Pechora. The company planned to cut down all forests along the rivers for fuel, but the factory ceased its operations after three years. The forests in the Kolva River basin provided the primary source of fuel for the salt production located on the Kama River. From the 1880s, between 22,000 to 30,000 cubic meters of firewood were collected annually. A significant amount of wood was employed in the construction of barges. By the end of the 19th century, the logging industry went through a reorientation. Logging activities for the harvest of saltwood and barge-building followed by the production of construction lumber for export to Volga markets replaced the focus on the logging industry, leading to approximately 50,000 log shipments yearly. Throughout the whole 19th century, the forests were left unexplored, without any management plans. There were no networks of roads in the area. Timber for building and barge construction was harvested selectively by landscape units. A few dozen trees of the required size were selectively harvested from each hectare. Clear-cutting sites for the harvesting of salt-wood were located no further than 1 to 3 kilometers from the majority of rafting rivers. The preserved archival materials are crucial for understanding past impacts and should be integrated into contemporary ecological research.

Spatiotemporal variability in the structure and diversity of understory faunal assemblages associated with the kelp Eisenia cokeri (Laminariales) in Peru

Kelp species function as foundation organisms in coastal marine ecosystems, where they alter environmental conditions and promote local biodiversity by providing complex biogenic habitat for an array of associated organisms. The structure and functioning of kelp forest ecosystems in some regions, such as along the Peruvian coastline, remain critically understudied. We quantified the structure and diversity of faunal assemblages within both holdfast and understory reef habitats within Eisenia cokeri forests. We sampled both habitat types within four subtidal kelp forests on multiple occasions between 2016 and 2020, and quantified fauna at a fine taxonomic level (mostly species). We recorded a total of ~ 55,000 individuals representing 183 taxa across the study, with holdfast assemblages typically exhibiting higher richness, abundance and biomass values compared with understory reef-associated assemblages. Holdfast assemblages were structurally and functionally dissimilar to those on reef surfaces and were less variable and consistent across sites and sampling events. Even so, assemblages associated with both habitat types varied significantly between sites and sampling events, with variation in upwelling strength, ocean currents, and grazing pressure among potential drivers of this ecological variability. Overall, E. cokeri supports diverse and abundant holdfast assemblages and functions as a foundation organism in Peru. Given that no other habitat-forming kelp species persist at the low latitudes of E. cokeri in mid-to-north Peru, the lack of functional redundancy suggests that effective management and conservation of this species is vital for wider ecosystem processes and biodiversity maintenance.

2013–2022年云南丽江森林生物多样性国家野外科学观测研究站日气象数据集

Meteorological factors are important environmental elements of field positioning observation stations of CNERN, CERN and CFERN. The acquisition of high-quality observational data through long-term positioning observations is beneficial for advancing our scientific understanding of ecosystem processes and tracking dynamic changes in biodiversity. It also provides important support for the development of regional and national ecological, environmental, and resource security construction initiatives. As one of the Forest Biodiversity National Observation and Research Stations approved in 2021, Lijiang Station has been collecting data in accordance with the CERN meteorological monitoring standards for past consecutive years. Up to now, Lijiang Station has consistently maintained comprehensive data parameters, a structured approach, and a high level of data standardization. These data can serve as important foundation for various research endeavors, including dynamic changes in the structure, processes, and functions of regional forest ecosystems, the formation, evolution, and preservation of regional biodiversity mechanisms, forest biodiversity and ecosystem functioning, the monitoring, evaluation, and conservation of biodiversity for key wild protected species, and the assessment and innovative exploitation of distinctive biological resources. This dataset comprises 3,652 entries and 39 fields of daily meteorological data spanning from 2013 to 2022. It covers atmospheric elements (air temperature and humidity, atmospheric pressure, wind speed and direction, precipitation, radiation elements) and soil elements (soil stratified temperature and soil heat flux). The release of the dataset offers comprehensive fundamental meteorological data for scientific research in related fields and provides essential data support for local and large-scale networking research.