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Tropical forest restoration presents a potential lifeline to mitigate climate change and biodiversity crises in the Anthropocene. Yet, the extent to which human interventions, such as tree planting, accelerate the recovery of mature functioning ecosystems or redirect successional trajectories toward novel states remains uncertain due to a lack of long-term experiments. In 2004-2006, we established three 0.25-ha plots at 10 sites in southern Costa Rica to test three forest restoration approaches: natural regeneration (no planting), applied nucleation (planting in patches), and plantation (full planting). In a comprehensive survey after 16-18 years of recovery, we censused >80,000 seedlings, saplings, and trees from at least 255 species across 26 restoration plots (nine natural regeneration, nine applied nucleation, eight plantation) and six adjacent reference forests to evaluate treatment effects on recruitment patterns and community composition. Both applied nucleation and plantation treatments resulted in significantly elevated seedling and sapling establishment and more predictable community composition compared with natural regeneration. Similarity of vegetation composition to reference forest tended to scale positively with treatment planting intensity. Later-successional species with seeds ≥5 mm had significantly greater seedling and sapling abundance in the two planted treatments, and plantation showed similar recruitment densities of large-seeded (≥10 mm) species to reference forest. Plantation tended toward a lower abundance of early-successional recruits than applied nucleation. Trees (≥5 cm dbh) in all restoration treatments continued to be dominated by a few early-successional species and originally transplanted individuals. Seedling recruits of planted taxa were more abundant in applied nucleation than the other treatments though few transitioned into the sapling layer. Overall, our findings show that active tree planting accelerates the establishment of later-successional trees compared with natural regeneration after nearly two decades. While the apparent advantages of higher density tree planting on dispersal and understory establishment of larger seeded, later-successional species recruitment is notable, more time is needed to assess whether these differences will persist and transition to the more rapid development of a mature later-successional canopy. Our results underscore the need for ecological restoration planning and monitoring that targets biodiversity recovery over multiple decades.

Societal Impact Statement: Forests worldwide face significant challenges due to climate change, impacting their health and productivity. In this study, we examined how European beech and Scots pine influence each other's phenology and growth in mixed forests. Our findings indicate that mixing these complementary tree species can increase resource efficiency within forest ecosystems. By leveraging informed species selection, this research highlights the potential for developing knowledge‐based, resource‐efficient forests. These insights are invaluable for policymakers and forest managers in designing forests that are not only productive but also sustainable and adaptable to evolving environmental conditions. Summary: We investigated the effects of interspecific neighbors on crown morphology and growth efficiency in European temperate forests, specifically focusing on European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.). Our goal was to determine whether the previously reported overyielding in this mixture is primarily due to improved space‐use efficiency and packing density or enhanced resource‐use efficiency.Our methodology involved a detailed analysis of 128 individual felled trees. We assessed the effect of intraspecific and interspecific neighbors on stem volume growth, the allometric relationships of tree crowns and their components, and the allocation of branch and leaf biomass along the trees' vertical structure.Our findings demonstrate that interspecific neighbors significantly influence the allometric relationships of tree crowns, especially altering the vertical biomass distribution in European beech. Additionally, we found that interspecific neighbors can significantly enhance the growth efficiency of European beech but not for Scots pine.This research provides valuable insights for enhancing forest growth models and guiding forest management practices. By understanding the critical role of crown biomass allocation and growth efficiency in mixed‐species stands, policymakers and forest managers can design forests that are both productive and adaptable to changing environmental conditions. This study emphasizes the importance of species interactions in forest dynamics and bridges theoretical concepts with practical applications. [ABSTRACT FROM AUTHOR]

Summary: Here, we developed and applied models to quantitatively reconstruct forest cover and biomass changes at three lakes in northwestern Amazonia over the past > 1500 yr.We used remotely sensed data and a modern dataset of 50 Amazonian lakes to develop generalized linear models that predict aboveground biomass, using phytolith morphotypes and forest cover as predictor variables. Also, we applied a published beta regression model to predict forest cover within 200 m of each lake, using Poaceae phytoliths. Charcoal and maize phytoliths were analysed to identify past land use.Results showed forest cover and biomass changes at our study sites ranged between 48–84% and 142–438 Mg ha−1, respectively. Human occupation was discontinuous, with major changes in forest cover and biomass coinciding with periods of land use. Forest cover and biomass decreased notably after fire (at all sites) or cultivation events (Lakes Zancudococha, Kumpaka). The timing and ecological impact of past land use were spatially and temporally variable.Our results suggest past human impact was small‐scaled and heterogenous in northwestern Amazonia, with a significant impact of fire on forest cover and biomass changes. [ABSTRACT FROM AUTHOR]

Although integration systems have been used since ancient times in various types of plantations, the adoption of integrated systems and their practices involving cattle and forest species are still considered innovative in the Brazilian agricultural context. In light of this, this study evaluated the growth and production of four forest species in a silvopastoral system, six years after planting in the field. The experiment was installed using a randomized block design with a 4 × 3 factorial scheme, consisting of four forest species (Aspidosperma polyneuron Mull. Arg., Eucalyptus cloeziana F. Muell., Khaya senegalensis (Desv.) A. Juss, and Swietenia macrophylla King.) and three spacings (3 × 2 m; 3 × 3 m; 3 × 4 m), with four replications and plots composed of 18 plants, totaling 864 plants. To evaluate the growth and production of the species, total height (Ht), diameter at breast height (DBH), and height of the breast (H) were measured, and the sectional area per plant (g), basal area per hectare (G), volume per plant (Vol/ind), volume per hectare (Vol/ha), and mean annual increment (MAI) were calculated. The results indicated that all variables were influenced by species, while basal area and volume per hectare were affected by spacing. E. cloeziana and K. senegalensis exhibited better growth and productivity at the 3 × 2 spacing compared to A. polyneuron and S. macrophylla. Regarding the survival of the species, K. senegalensis, A. polyneuron, E. cloeziana, and S. macrophylla showed survival rates of over 98%, 55.5%, 70.8%, and 54.1%, respectively, across all tested spacings. [ABSTRACT FROM AUTHOR]

The editorial discusses the role of managed forestry in climate change mitigation and adaptation, emphasizing the importance of forests in sequestering carbon and regulating water cycles. Managed forests can help reduce greenhouse gas emissions and increase resilience to climate change through practices like reforestation and improved silvicultural techniques. However, challenges such as quantifying carbon sequestration and ensuring economic viability remain. The article suggests further research and innovation, including advanced modeling tools and exploring forest-based products, to enhance the effectiveness of managed forestry in addressing climate change. [Extracted from the article]

Summary Tropical cyclones (TCs) sporadically cause extensive damage to forests. However, little is known about how TCs affect forest dynamics in mountainous terrain, due to difficulties in modelling wind flows and quantifying structural changes. Typhoon Mangkhut (2018) was the strongest TC to strike Hong Kong in over 40 yr, with gusts > 250 km h−1. Remarkably, the event was captured by a dense anemometer network and repeated LiDAR surveys across natural forests and plantations. We mapped long‐term mean and extreme wind speeds using CFD models and analysed corresponding changes in canopy height, which uncovered TC‐forest dynamics at unprecedented scales (> 400 000 pixels, 1108 km2). Forest height was more strongly limited by wind exposure than by background topography, a limitation attributable to a dynamic equilibrium between growth and disproportionate TC damage to taller forests. Counterintuitively, wind‐sheltered forests also suffered heavy damage. As a result, canopies of wind‐sheltered forests were more rugged, which contrasted with flat‐topped forests at wind‐exposed sites. Plantations were more susceptible to TCs compared to natural rainforests of similar stature (canopy height change −0.86 m vs −0.39 m). Our findings highlight TCs as important, often overlooked factor that fundamentally shapes forest structure and dynamics. [ABSTRACT FROM AUTHOR]

Disturbance regimes, like low‐intensity fire, canopy gaps and ungulate browsing, play a critical role in determining ecological composition and structure in temperate forests around the world. Each disturbance (or lack thereof) can lead to unique plant communities, but we do not understand how combined disturbances change plant diversity and the resulting soil seed bank. Changes in the soil seed bank, which depend on the plants that survive post‐disturbance, can then influence future biodiversity and succession. We used a long‐term experiment in West Virginia, USA, that factorially manipulated low‐intensity fire, deer exclusion and canopy gaps. Thirteen years after disturbance initiation, we sampled the seed bank from each disturbance treatment. We found that low‐intensity fire led to increased seed bank density, with additional canopy gaps and deer exclusion each creating unique seed bank communities. Combined fire, canopy gaps and deer presence led to high seed bank diversity and the most unique seed communities, while canopy gaps and deer had no effect on seed banks unless the area was previously burned. In contrast, combined fire, canopy gaps and deer exclusion led to the lowest seed bank diversity of all treatments, reflecting the continued legacy of extant plants that grew immediately after disturbance. Seed communities were also distinct from extant understory species over 13 years, regardless of disturbance treatment. Each reintroduced disturbance combination left a unique legacy in the seed bank that will likely influence future forest reorganization following disturbances, adding to our understanding of how multiple disturbances influence forest succession and organization. Synthesis. Forest disturbance regimes have changed around the world and are being restored or manipulated to support biodiversity. Reintroduction of disturbance leads to unique plant communities, but we do not understand how combined disturbances change the soil seed bank. Using an experiment that manipulates low‐intensity fire, canopy gaps and deer exclusion, we find that combinations of these experimental treatments leads to substantially different seed communities. These disturbance‐altered seed banks will likely influence future biodiversity and successional patterns, highlighting how the restoration of disturbance can strongly and indirectly influence temperate forest community dynamics. [ABSTRACT FROM AUTHOR]

As long‐lived tropical trees grow into the multi‐layered canopy and face different environmental conditions, the relationships between leaf traits and whole‐plant survival can vary over ontogeny. We tested the strength and direction of the relationships between leaf traits and long‐term survival data across life stages for woody species from a subtropical forest in Puerto Rico. Trait–survival relationships were largely consistent across ontogeny with conservative traits leading to higher survival rates. The stage‐specific relationship R2 increased by up to one order of magnitude compared to studies not considering ontogenetic trait variations. Stage‐specific traits were significant predictors of their corresponding stage‐specific survival: Seedlings traits were better predictors of seedling survival than adult traits, and adult traits were better predictors of maximum adult survival than seedling traits. Our results suggest that stage‐specific leaf traits reflect different strategies over ontogeny and can substantially improve predictability of survival models in tropical forests. [ABSTRACT FROM AUTHOR]

Mast seeding, the synchronous and highly variable production of seed crops by perennial plants, is a population‐level phenomenon and has cascading effects in ecosystems. Mast seeding studies are typically conducted at the population/species level. Much less is known about synchrony in mast seeding between species because the necessary long‐term data are rarely available. To investigate synchrony between species within communities, we used long‐term data from seven forest communities in the U.S. Long‐Term Ecological Research (LTER) network, ranging from tropical rainforest to boreal forest. We focus on cross‐species synchrony and (i) quantify synchrony in reproduction overall and within LTER sites, (ii) test for relationships between synchrony with trait and phylogenetic similarity and (iii) investigate how climate conditions at sites are related to levels of synchrony. Overall, reproductive synchrony between woody plant species was greater than expected by chance, but spanned a wide range of values between species. Based on 11 functional and reproductive traits for 103 species (plus phylogenetic relatedness), cross‐species synchrony in reproduction was driven primarily by trait similarity with phylogeny being largely unimportant, and synchrony was higher in sites with greater climatic water deficit. Community‐level synchrony in masting has consequences for understanding forest regeneration dynamics and consumer‐resource interactions. [ABSTRACT FROM AUTHOR]

Wildfire risk increases following non-fire disturbance events, but this relationship is not always linear or cumulative, and previous studies are not consistent in differentiating between disturbance loops versus cascades. Previous research on disturbance interactions and their influence on forest fires has primarily focused on fire-prone regions, such as North America, Australia, and Southern Europe. In contrast, less is known about these dynamics in Central Europe, where wildfire risk and hazard are increasing. In recent years, forest disturbances, particularly windthrow, insect outbreaks, and drought, have become more frequent in Central Europe. At the same time, climate change is influencing fire weather conditions that further intensify forest fire dynamics. Here, we synthesize findings from the recent literature on disturbance interactions in Central Europe with the aim to identify disturbance-driven processes that influence the regional fire regime. We propose a conceptual framework of interacting disturbances that can be used in wildfire risk assessments and beyond. In addition, we identify knowledge gaps and make suggestions for future research regarding disturbance interactions and their implications for wildfire activity. Our findings indicate that fire risk in the temperate forests of Central Europe is increasing and that non-fire disturbances and their interactions modify fuel properties that subsequently influence wildfire dynamics in multiple ways. [ABSTRACT FROM AUTHOR]

Wildfires and drought stressors can significantly limit forest recovery in Mediterranean-type ecosystems. Since 2010, the region of central Chile has experienced a prolonged Mega Drought, which intensified into a Hyper Drought in 2019, characterized by record-low precipitation and high temperatures, further constraining forest recovery. This study evaluates short-term (5-year) post-fire vegetation recovery across drought gradients in two types of evergreen sclerophyllous forests and a thorny forest and shrubland, analyzing Landsat time series (1987–2022) from 42 wildfires. Using the LandTrendr algorithm, we assessed post-fire forest recovery based on NDVI changes between pre-fire values and subsequent years. The results reveal significant differences in recovery across drought gradients during the Hyper Drought period, among the three forest types studied. The xeric forest, dominated by Quillaja saponaria and Lithrea caustica, showed significant interaction effects between levels of drought and fire severity, while the thorny forest and shrubland displayed no significant interaction effects. The mesic forest, dominated by Cryptocarya alba and Peumus boldus, exhibited additional significant differences in recovery between the Hyper Drought and Mega Drought periods, along with significant interaction effects. These findings underscore the critical role of prolonged, severe drought in shaping forest recovery dynamics and highlight the need to understand these patterns to improve future forest resilience under increasingly arid conditions. [ABSTRACT FROM AUTHOR]

Despite the medicinal benefits of Pueraria lobata (kudzu), it stands as an invasive species that disrupts forest ecosystems, prompting the exploration of natural predators for its control. This study presents the first comprehensive report on Lema (Lema) diversipes, Pic, 1921, a beetle species that uses kudzu as its host, with significant implications for forest ecosystem dynamics. Detailed morphological descriptions and illustrations of its larva stage are provided for the first time. Additionally, partial sequences of mitochondrial cytochrome c oxidase subunit I, a domestic distribution map, and biological notes are included. [ABSTRACT FROM AUTHOR]

In landscapes with high elephant density, trees often exhibit more open canopies with fewer branches and foliage due to browsing pressure. This can result in altered tree morphology, with trees exhibiting stunted growth, multiple stems or unusual branching patterns in response to repeated damage from browsing. The objectives of this research were to (i) model the vegetation structure allometries, (ii) assess the impact of African savannah elephant (Loxodonta africana) herbivory on the vegetation structure and (iii) assess tree cover change and vegetation performance over time in Mana Pools National Park in Zimbabwe. We established 26 plots of 30 × 30 m size. Selection of sampling plots was done following several steps. First, a fish net grid with 30 × 30 m polygons was created and projected on the polygon of Mana Pools National Park. The polygons for exclusion zones were then clipped from the fish net grid using the clip tool in ArcGIS Pro 3.0. Then, selection of sampling plots was done initially by stratified random sampling using the Sampling Design Tool add in for ArcGIS Pro 3.0. Landsat images for the years 2003, 2013 and 2023 were used to assess land use land cover (LULC) time series and to calculate Normalised Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) for the period. A generalised linear model (GLM) was used to analyse tree allometries. Further statistical investigations were performed using Bayesian piecewise regression (BPR) and Bayesian regression modelling (BRM). Basal area, number of stems, height, long canopy, diameter and basal circumference were all significantly different (p < 0.05) across all sampled plots. The change in growing conditions occurring as a tree grows beyond the reach of the African savannah elephant browsing indicates a natural system breakpoint. The best‐fitting models were a simple linear model and a two breakpoint model for the plant population exposed to elephant herbivory. LULC, NDVI and SAVI confirm evidence of high tree regeneration over 2 decades. Understanding the dynamics in vegetation and LULC changes is critical for effective conservation and management of the habitats for African savannah elephants, as well as for maintaining the health and resilience of forest ecosystems. [ABSTRACT FROM AUTHOR]

Background: Science‐based decisions regarding forest management require the knowledge of the impact of thinning regimens on the forests' vitality and resilience. There is no systematic study analysing the role of forest management approaches on the nutritional status of forests, serving as a surrogate for their health and growth. Aims: We assessed the impact of 'heavy thinning from above' versus 'no management' on the foliar chemistry of old‐growth European beech stands on a calcareous site with cambisol/chromic luvisol soil in Thuringia, Germany. Methods: Macro‐ and micronutrients were analysed by serial foliar analysis of six trees per experimental plot over 13 years (2009–2021). To assess potential differences of foliar chemistry between the two plots and over time, a linear mixed‐effects model was applied. Results: Foliar concentrations of all macro‐ and micronutrients were not significantly different between the two plots (p > 0.05), demonstrating that the management approach had no relevant impact on the nutritional status of beech trees growing at the calcareous site. Furthermore, all foliar concentrations were dynamic over the 13‐year evaluation period. Hence, long‐term forest monitoring is crucial to capture the complex interplay between the trees and environmental conditions. Conclusions: Serial foliar analysis allows for a reliable evaluation of a forest's nutritional status. The results indicate that either regimen, that is, 'heavy thinning from above' or 'no management', shall not pose any risk in terms of growth and stability. Our results add to the understanding of beech forest dynamics and may provide a further piece for science‐based strategies of sustainable forest management. [ABSTRACT FROM AUTHOR]

The study of the holm oak forests of the lower and upper mesomediterranean of the south of the Iberian Peninsula, and new syntaxons of holm oak forests not assigned until now are contributed. The plant dynamics is provided and completed, and the importance of the learning of plant description and dynamics by university students, future environmental managers, is specified. Taking into account the strong anthropic action with the consequent destruction of holm oak forests, it is necessary to enhance the knowledge of plant dynamics to decipher the potential vegetation, and to be able to apply the vegetation series as a basis for agronomic and forestry management. In this work, we propose a new vegetation series. We propose the association Aristolochio baeticae-Quercetum rotundifoliae nova for the biogeographic sector Granadino-Almijarense (Montes de Málaga) and as a first dynamic stage of the microforest of Olea europea var. sylvestris obtained by deforestation. The study of the Iberian olive groves allows us to propose two new associations Aristolochio baeticae-Oleetum sylvestris and Ephedro fragilis-Oleetum sylvestris. [ABSTRACT FROM AUTHOR]

In 2012, was published to guide policy and research and to support Canada's obligations for climate change mitigation and adaptation, sustainable forest management, and international reporting. Over the past decade, the body of scientific research focused on forest carbon dynamics in Canada has significantly evolved, providing crucial insights into the intricate interplay between various forest ecosystems and the global carbon cycle. This comprehensive review synthesizes key findings from this period, highlighting improvements to Canada's estimates of current forest greenhouse gas (GHG) emissions and removals, the effects of global changes on Canada's future forest carbon, and forest contributions to mitigate climate change. Collaborating with the forest carbon science community, we identified 426 peer-reviewed published articles on landscape-scale forest carbon research for Canada from 2012 to 2021. The review emphasizes anthropogenic influences and natural disturbances in contemporary GHG emissions and removals for managed forests in the national GHG inventory, highlights the existing dichotomy between management and research models, and stresses the need for integrating disturbance and climate effects for comprehensive GHG estimates. Despite significant progress in estimating and tracking forest carbon using modelled, remotely sensed, and ground-based observations, challenges remain in reducing uncertainties, particularly regarding climate impacts on forest growth, decay, and disturbances. Furthermore, the review showcases recent advancements in climate change mitigation strategies and the use of a systems approach that includes forest ecosystem emissions and removals, wood product emissions, and substitution benefits of avoided fossil emissions. Through comprehensive scenario analyses, the review underscores regional variations in assessing GHG reductions and notes a shift towards a more holistic approach that considers environmental, economic, and social values. By providing a nuanced understanding of the complexities underlying forest carbon dynamics in Canada, this review sets the stage for future research and policy initiatives aimed at fostering sustainable forest management practices and mitigating the impact of climate change on these vital ecosystems. [ABSTRACT FROM AUTHOR]

Fine root decomposition is an important driver of forest carbon (C) and nutrient cycling. Harvesting operations may affect fine root decomposition rates by altering root properties and environmental conditions, but our understanding of root dynamics is limited. In this study, we investigated the chemistry, mass loss, element release (C, nitrogen (N), and phosphorus (P)), and compound release (lignin and cellulose) of decaying fine roots in a 26 year-old Chinese fir plantation seven years after low- and high-intensity thinning (30% and 70% tree removal) using two root size classes (< 1 mm and 1–2 mm diameter). Low-intensity thinning (LIT) did not affect mass loss in either fine root class or the release of fine root elements or compounds during decomposition. Similarly, high-intensity thinning (HIT) had no effect on the decomposition of large fine roots. However, compared with LIT and no thinning, HIT reduced the decay rates and lignin and cellulose losses of small fine roots. This reduction was related to an increase in the root lignocellulose index (lignin/[lignin + cellulose]) and a decrease in soil invertase activity. Interestingly, thinning did not affect root C, N, or P loss during decomposition. In summary, our results suggest that thinning intensity as well as root size and chemistry should be considered when studying fine root dynamics in managed forests. [ABSTRACT FROM AUTHOR]

Marginal populations of temperate species at the leading edge of their range will likely play a key role at the boreal‐temperate ecotone (BTE) in the face of climate changes. In eastern North America, red maple (Acer rubrum L.) is the most abundant temperate tree species encroaching into the boreal forest. In order to provide useful insights about possible responses to climate change and anticipate the formation of new assemblages, this study relies on long‐term Holocene data from forest soil wood macrofossils (charcoal and ligneous remains) and contemporary stand analyses to assess the postglacial origin and modern‐day dynamics of red maple at its leading edge within the BTE. We sampled the soils of eight marginal red maple stands. Macroscopic charcoal particles and ligneous remains were identified using microanatomical characteristics. Macrofossils of temperate tree species were radiocarbon dated to reconstruct their long‐term stand‐scale history. Contemporary dynamics (<200 years) were assessed by analyzing tree size structure of all stems within 400 m2 plots, minimal stand age from tree‐ring dating, as well as the recent occurrence of fire and logging from published ecoforest data. White pine (Pinus strobus L.), the only other temperate tree species that was identified, was present 6500–4000 years ago, during the mid‐Holocene thermal maximum but decreased during the cooler and fire‐prone late‐Holocene Neoglacial (4000 years ago to present). By contrast, red maple was found at its current northern limit since the last 4000 years. Modern‐day marginal red maple stands are self‐regenerating populations that established following a recent stand‐replacing disturbance (wildfire or clearcut). The present‐day increase of anthropogenic disturbances within the BTE could mirror the Neoglacial increase in fire activity that fostered red maple during the Holocene. We thus predict that red maple is poised to increase in abundance within the BTE, which should facilitate the northward establishment of other temperate deciduous species into the boreal forest prompted by the new conditions brought about by anthropogenic or climate change‐induced disturbances. [ABSTRACT FROM AUTHOR]

The spatiotemporal dynamics of forest cover are essential for understanding the patterns and processes of forest change over time and space. This research focused on the spatiotemporal trends and drivers of forest cover change in the Metekel Zone of Northwest Ethiopia. Landsat 5, Landsat 7, and Landsat 8 imagery, covering the period from 1986 to 2019, were used for land use/cover classification. Land use/cover classification was performed using random forest (RF) and support vector machine (SVM) algorithms in the Google Earth Engine (GEE) platform, with training samples obtained through visual image interpretation. Spectral indices, such as the normalized difference vegetation index, soil-adjusted vegetation index, leaf area index, and normalized difference water index, were analyzed to examine forest cover dynamics over time. In addition, key informant interviews (KIIs) and focus group discussions (FGDs) were conducted. Findings revealed that forest cover decreased significantly from 51.37% in 1986 to 17.20% in 2019, driven largely by human activities such as agricultural expansion, increased demand for firewood, and urban expansion. Findings from spectral indices further corroborated the finding that forest cover in the study region (mainly in the southwestern part) substantially decreased from 1986 to 2019. Concerning forest depletion, the lack of local community awareness has become a key challenge. This problem is attributed to communities prioritizing immediate needs such as fuel and land for agriculture over long-term forest conservation. To combat ongoing deforestation, the Metekel Zone Administration, in collaboration with the land administration office and other stakeholders, revisited and strengthened existing forest policies and control systems. It is also suggested that community awareness, chiefly among youth, should be enhanced through the strategic expansion of formal and nonformal educational initiatives, which empower the youth as agents of change and promote the dissemination of knowledge throughout the community. [ABSTRACT FROM AUTHOR]

The internal retranslocation of nutrients of senescence leaves is a significant aspect of nutrient dynamics in a forest ecosystems. The present investigation was carried out by considering four types of deciduous tree species (Shorea robusta, Tectona grandis, Schleichera oleosa, and Albizia lebbeck) to assess nutrient resorption efficiency (NuRE) and resorption proficiency (NuRP) of nitrogen (N), phosphorous (P), and potassium (K), as well as seasonal changes of nutrient concentration in green and senescence leaves. Green and senescent leaves were sampled and analysed for NPK concentration by standard methods. Experimental results revealed that the higher nutrition contents were recorded in green leaves than senescence leaves. The highest N and P resorption efficiency (RE) were recorded for S. robusta and lowest for T. grandis (46.74%) and A. lebbeck (37.93%) respectively, whereas T. grandis exhibited the highest resorption efficiency of K (47.67%) and lowest for A. lebbeck (40.29%). Furthermore, the highest percentage of nutrients from mature leaves and soil were transported to the tree body during senescence were 47.0% (S. oleosa), and 21.29% (T. grandis), respectively. Moreover, nutrients were retranslocated from senescent leaves in the order as N > P > K. On the other hand, the nutrient resorption proficiency (NuRP) was highest with respect to N (53.26%) and P (62.07%) for T. grandis and K (59.71%) for A. lebbeck. Similarly, the lowest with respect to N (44.27%) and P (50.91%) for S. robusta, and K (52.33%) for T. grandis. Therefore, it can be concluded that changes in nutrient concentrations in green and senescence leaves could be the possible reason for different retranslocation efficiency. [ABSTRACT FROM AUTHOR]

Forest-grassland mosaics comprise a major component of tropical landscapes, hosting invaluable biodiversity and providing essential ecosystem services to hundreds of millions of people worldwide. While open biomes often benefit from disturbance, forests can particularly be susceptible to structural changes resulting from such disruptions. Here we evaluate the influence of fire on the structure and landscape properties within natural forest islands immersed in a matrix of megadiverse montane grasslands. We conducted this study in 15 forest islands located in southeastern Brazil, assessing its fire frequency, intensity, and post-fire time over an eleven-year period from January 2012 to December 2022. Our results show that fire frequency is linked to soil characteristics and the percentage of herbaceous cover within the forest islands. We also found that the post-fire time is related to the percentage cover of the forest islands' associated herbs and shrubs. However, neither fire frequency, intensity, nor post-fire time was connected to significant changes in plant species richness, abundance, or in the upper vegetation strata (tree species richness and abundance, and canopy cover) in the interior of the forest islands. Furthermore, these fire-related variables did not result in temporal changes in the forest island's canopy variation or landscape metrics. Our results underscore a low fire frequency and intensity within our study area, potentially explaining the limited fire-associated impact, and primarily on the lower vegetation strata. Despite acknowledging the relative stability of these forest islands under current fire regimes, we suggest further studies that can experimentally manipulate not only fire but also other anthropic disturbances for understanding the temporal dynamics of the forest islands and, consequently, their preservation. This perspective is indispensable for comprehensively understanding the ecological consequences of anthropogenic disturbances in natural forest islands. [ABSTRACT FROM AUTHOR]

The increase in extreme climate events in recent years has been considered as an important factor affecting forest pests. Understanding the responses of forest pests to climate is helpful for revealing the trends in forest pest dynamics and proposing effective control measures. In this study, the relationship between the dynamics of all forest pests, independent forest diseases, and forest insect pests with the climate was evaluated in China, and the corresponding differences among forest pests, diseases and insect pests were assessed. Based on cross-wavelet transform and wavelet coherence analysis, the influences of teleconnection factors on the relationship between climate and forest pests were quantitatively analyzed to determine the roles of these factors. The results indicate that (i) three types of disasters in most parts of China have decreased from 1979 to 2019, while forest pests and forest insect pests in the southwestern region have increased; (ii) the relationship among Forest Pest Occurrence Area Rate and climate factors such as the Multivariate ENSO index, Southern Oscillation index, Arctic Oscillation (AO), Atlantic Multidecadal Oscillation (AMO), and Sunspot is more significant; (iii) the cycle is short in most regions, with oscillations in 2–4 years bands being the main variation periods of disasters in East, Central, and South China; (iv) There is a significant correlation between climate and disasters in the periods of 2–4 or 8–10 years. The AO, AMO, and Sunspot were important driving factors affecting the relationship between climate and disasters. Specifically, the Sunspot had the greatest impact among these factors. [ABSTRACT FROM AUTHOR]

Wildfire simulations can help to better understand the dynamics and effects of forest fires. The basis of wildfire simulation is the tree-burning simulation. In this paper, the fire simulation of 7 different geometry Hungarian trees in the case of arson is presented. It was observed that the trees were burned down fast. The maximum mass loss rate and maximum heat release rate were larger as the tree was larger. The largest intensity fire could be observed in the case of the smallest tree. The maximum temperature was higher in the case of a large crown diameter. The maximum aerosol reached high pollutant concentrations. In the case of large crown height, the maximum CO2 concentration was higher. The results presented in this paper can be the basis of the following forest fire simulations. [ABSTRACT FROM AUTHOR]

New remote-sensed biomass change products will transform our capacity to monitor and validate large-scale carbon dynamic in the next decade. In this study, we evaluated the use of multitemporal Airborne Laser Scanning (ALS) and the Climate Change Initiative (CCI) BIOMASS spaceborne mission to estimate AGB dynamics in different Mediterranean forest over an 8-year period (2010–2018). To do so, we evaluated different maps to estimate change in AGB, specifically indirect approach using forest-type specific ALS-based AGB maps using i) countrywide ALS coverage at 25 m resolution (2010–2018) and ii) the global, 100-m resolution CCI maps version 3 (2010–2018). The change in AGB (ΔAGB) was mapped across the study region to compute dynamics by forest type. Our results suggest that the indirect approach using ALS-model-based produced more accurate estimates in change of AGB than CCI when we compared with the design-based AGB estimation using Spanish National Forest Inventory (SNFI) at strata level. The spatial representation of the AGB change indicated that ΔAGB-ALS changes by forest type had an overall gain in biomass at regional level. The ΔAGB total and net annual changes by year and area (ΔAGB, Mg ha−1 year−1) were closed to the values obtained using SNFI at strata level. This study demonstrates the feasibility of enhancing carbon sequestration and stock capacity in Mediterranean forest using multitemporal ALS data and the limitations of global AGB maps at Regional Scale. [ABSTRACT FROM AUTHOR]

In the context of ongoing threats to forest ecosystems, this study investigates the temporal and spatial dynamics of Lymantria dispar defoliation intensity over a period of three years. We analysed the relationship between the insects' reproductive and feeding behaviours and forest stand characteristics, exploring the key factors that shape this behaviour. The results revealed a dynamic pattern, with a significant escalation of defoliation starting from the second year and peaking in the third. The analysis highlighted that, among several forest stand characteristics, woody species abundance and specific forest composition significantly influence population density and defoliation intensity. Sporadic outbreaks of the insects were associated with stand features, posing major challenges to forest health. These findings make a significant contribution to understanding the population dynamics of L. dispar and provide essential insights for forest managers in efficiently managing this defoliator. By highlighting the complex interactions between the insect and its environment, this study lays the groundwork for conservation and protection strategies for forest ecosystems. [ABSTRACT FROM AUTHOR]

Tree successional diversity is evident even to casual observers and has a well-understood physiological basis. Various life history trade-offs, driven by interspecific variation in a single trait, help maintain this diversity. Conspecific negative density dependence (CNDD) is also well-documented and reduces tree vital rates independently of succession strategies. The CNDD hypothesis is frequently justified by specialist natural enemies at a separate trophic level. We integrate these processes into an analytical demographic model, spanning short-term plant physiological responses to the dynamics of a large forest mosaic connected to a metacommunity. Surprisingly, multiple trade-offs do not necessarily increase diversity, as suboptimal trait combinations lead to strategies that cannot compete for successional niches, explaining the weak correlation between functional traits and succession position. Succession alone can sustain half of the species in the metacommunity, with diversity increasing linearly with CNDD strength. The steeper increase with larger metacommunities suggests CNDD plays a greater role in tropical forests. However, if each successional type contains multiple equivalent species, CNDD maintains diversity but becomes less effective in promoting successional diversity, consistent with some tropical forests being less successional diverse. Additionally, CNDD enhances the likelihood of successful speciation and shifts life-history trait frequency by affecting more late-successional species. The study introduces an analytical forest diversity model that integrates gap-phase successional dynamics, conspecific negative density dependence (e.g., natural enemies), and evolutionary processes, connecting the forest mosaic to a metacommunity. [ABSTRACT FROM AUTHOR]

Diverse drivers such as climate, soil fertility, neighborhood competition, and functional traits all contribute to variation in tree stem demographic rates. However, these demographic drivers operate at different scales, making it difficult to compare the relative importance of each driver on tree demography. Using c. 20,000 stem records from New Zealand's temperate rain forests, we analyzed the growth, recruitment, and mortality rates of 48 tree species and determined the relative importance of demographic drivers in a multilevel modeling approach. Tree species' maximum height emerged as the one most strongly associated with all demographic rates, with a positive association with growth rate and negative associations with recruitment and mortality rates. Climate, soil properties, neighborhood competition, stem size, and other functional traits also played significant roles in shaping demographic rates. Forest structure and functional composition were linked to climate and soil, with warm, dry climates and fertile soil associated with higher growth and recruitment rates. Neighborhood competition affected demographic rates depending on stem size, with smaller stems experiencing stronger negative effects, suggesting asymmetric competition where larger trees exert greater competitive effects on smaller trees. Our study emphasizes the importance of considering multiple drivers of demographic rates to better understand forest tree dynamics. [ABSTRACT FROM AUTHOR]

Populations of forest trees exhibit large temporal fluctuations, but little is known about the synchrony of these fluctuations across space, including their sign, magnitude, causes and characteristic scales. These have important implications for metapopulation persistence and theoretical community ecology. Using data from permanent forest plots spanning local, regional and global spatial scales, we measured spatial synchrony in tree population growth rates over sub-decadal and decadal timescales and explored the relationship of synchrony to geographical distance. Synchrony was high at local scales of less than 1 km, with estimated Pearson correlations of approximately 0.6–0.8 between species' population growth rates across pairs of quadrats. Synchrony decayed by approximately 17–44% with each order of magnitude increase in distance but was still detectably positive at distances of 100 km and beyond. Dispersal cannot explain observed large-scale synchrony because typical seed dispersal distances (<100 m) are far too short to couple the dynamics of distant forests on decadal timescales. We attribute the observed synchrony in forest dynamics primarily to the effect of spatially synchronous environmental drivers (the Moran effect), in particular climate, although pests, pathogens and anthropogenic drivers may play a role for some species. [ABSTRACT FROM AUTHOR]

ABSTRACT The non‐native invasive box‐tree moth (Cydalima perspectalis) causes severe damage to ornamental box trees (Buxus spp.) and natural boxwood stands (Buxus sempervirens). Using two light traps, we recorded the seasonal flight activity and abundance of C. perspectalis in the suburbs of Basel (Switzerland) over a 15‐year period (2009–2023) shortly after the moth's introduction to Europe in 2007. In each year, we also assessed the grazing damage and number of box‐tree larvae in a nearby natural box‐tree forest. We recorded two peaks in the number of C. perspectalis caught in the settlement area (2009–2010 and 2017–2018). Cross‐correlation analysis showed that waves of C. perspectalis moths invaded the settlement area in the year after the peak years of forest damage. Moderate numbers of C. perspectalis were caught each year during off‐peak periods. The outbreaks of C. perspectalis resulted in a complete defoliation of the box trees in the forest, after which the moth population collapsed. The slowly regenerating box‐tree forest was recolonised by C. perspectalis, most probably from the settlement area. After the second outbreak, the box‐tree forest did not appear to be able to fully recover, as moderate numbers of C. perspectalis larvae fed on the emerging new leaves. The annual mean temperature measured in Basel increased by 1.5°C between 2009 and 2023. During this period, the first C. perspectalis moths were caught earlier each year and the last moths were caught later each year. Thus, the duration of flight activity of C. perspectalis (all three generations of a year combined) increased from 13 weeks in 2010 to 20 weeks in 2023, indicating the impact of climate warming. Our study shows that the dynamics of C. perspectalis in the settlement area are strongly influenced by the presence of box trees in the adjacent forest. [ABSTRACT FROM AUTHOR]

Summary: As temperature rises, net carbon uptake in tropical forests decreases, but the underlying mechanisms are not well understood. High temperatures can limit photosynthesis directly, for example by reducing biochemical capacity, or indirectly through rising vapor pressure deficit (VPD) causing stomatal closure.To explore the independent effects of temperature and VPD on photosynthesis we analyzed photosynthesis data from the upper canopies of two tropical forests in Panama with Generalized Additive Models.Stomatal conductance and photosynthesis consistently decreased with increasing VPD, and statistically accounting for VPD increased the optimum temperature of photosynthesis (Topt) of trees from a VPD‐confounded apparent Topt of c. 30–31°C to a VPD‐independent Topt of c. 33–36°C, while for lianas no VPD‐independent Topt was reached within the measured temperature range. Trees and lianas exhibited similar temperature and VPD responses in both forests, despite 1500 mm difference in mean annual rainfall.Over ecologically relevant temperature ranges, photosynthesis in tropical forests is largely limited by indirect effects of warming, through changes in VPD, not by direct warming effects of photosynthetic biochemistry. Failing to account for VPD when determining Topt misattributes the underlying causal mechanism and thereby hinders the advancement of mechanistic understanding of global warming effects on tropical forest carbon dynamics. See also the Commentary on this article by Gauthey & Gardner, 244: 1119–1121. [ABSTRACT FROM AUTHOR]

While there is a global trend in kelp forests decline, sub-Antarctic Beagle Channel kelp ecosystems are among the most stable and extensive in the world, acting as a climatic refuge, indicating its high conservation value. Nevertheless, these coastal ecosystems are increasingly exposed to anthropogenic drivers that can affect kelp strategies and promote their replacement by turf. This study evaluated the urban impact of a coastal city in the Beagle Channel (Ushuaia, 54° S 68° W) on giant kelp (Macrocystis pyrifera) population dynamics. Seasonal samplings were conducted between 2020 and 2023 in two contrasting sites: an urban site directly exposed to Ushuaia pressures and a non-urban site. Our results indicate a reduction in both kelp adult density and kelp recruitment at the urban site. Here, high sediment inputs were the main factor affecting kelp recruitment, but higher density of potential grazers, and changes in the understory macroalgae assemblage were further observed. Morpho-functional composition and sediment trapped within the macroalgae suggest the prevalence of turf-forming algae dominating the urban site's understory assemblage. If neglected, the decline in kelp recruitment rates and the replacement of the forest by turf could eventually lead to a local loss of this urban-influenced sub-Antarctic kelp forest. [ABSTRACT FROM AUTHOR]

Continuous cover forestry is a silvicultural system designed to mimic natural forest dynamics and maintain the structure of uneven-aged semi-natural forests. One of the key steps in this approach is to create small gaps in the canopy by logging small groups of trees or individual trees. In gap-cutting, the main goal is to determine the optimal shape and size of these gaps in order to ensure spontaneous natural regeneration of the major tree species in the canopy. Yet, it remains relatively unknown how various arthropods respond to such forestry practices. Carabid beetles (Coleoptera: Carabidae) play an important role as predators of various small invertebrates and their predators are mostly vertebrates. The interactions between carabids and their predators might change due to shifts in the distribution of patches of suitable habitat as a result of forest management. Here, the aim was to determine whether gaps in the canopy of two diff erent sizes (small vs. large) and shapes (circular vs. elongated) can aff ect the predation pressure on large carabids in a Hungarian oak-hornbeam forest. Using 3D-printed decoys of the largest common carabid in the area, Carabus coriaceus, placed in each of the four gap treatments and control plots, the seasonal, diurnal, and treatment-specifi c aspects of predation pressure was estimated. This revealed no signifi cant eff ects of any of the variables included in this study, which indicates that predation pressure in undisturbed controls located in closed forests and small canopy gaps did not diff er signifi cantly. Creating gaps in the canopy by felling few trees seems to be a good strategy for maintaining the forest ecological network with minimal disruption compared clear-felling large areas. [ABSTRACT FROM AUTHOR]

Fires affect forest dynamics in seasonally dry regions such as the Mediterranean Basin. There, fire impacts on tree growth have been widely characterized in conifers, particularly pine species, but we lack information on broadleaf tree species that sprout after fires. We investigated post-fire radial growth responses in two coexisting Mediterranean hardwood species (the evergreen Quercus ilex, the deciduous Celtis australis) using tree-ring width data. We compared growth data from burnt and unburnt stands of each species subjected to similar climatic, soil and management conditions. We also calculated climate–growth relationships to assess if burnt stands were also negatively impacted by water shortage, which could hinder growth recovery. Tree-ring data of both species allowed us to quantify post-fire growth enhancements of +39.5% and +48.9% in Q. ilex and C. australis, respectively, one year after the fire. Dry spring climate conditions reduced growth, regardless of the fire impact, but high precipitation in the previous winter enhanced growth. High June radiation was negatively related to the growth of unburnt Q. ilex and burnt C. australis stands, respectively. Post-fire growth enhancement lasted for five years after the fire and it was a transitory effect because the growth rates of burnt and unburnt stands were similar afterwards. [ABSTRACT FROM AUTHOR]

New (a)biotic conditions resulting from climate change are expected to change disturbance dynamics, such as windthrow, forest fires, droughts, and insect outbreaks, and their interactions. These unprecedented natural disturbance dynamics might alter the capability of forest ecosystems to buffer atmospheric CO2 increases, potentially leading forests to transform from sinks into sources of CO2. This study aims to enhance the ORCHIDEE land surface model to study the impacts of climate change on the dynamics of the bark beetle, Ips typographus, and subsequent effects on forest functioning. The Ips typographus outbreak model is inspired by previous work from Temperli et al. (2013) for the LandClim landscape model. The new implementation of this model in ORCHIDEE r8627 accounts for key differences between ORCHIDEE and LandClim: (1) the coarser spatial resolution of ORCHIDEE; (2) the higher temporal resolution of ORCHIDEE; and (3) the pre-existing process representation of windthrow, drought, and forest structure in ORCHIDEE. Simulation experiments demonstrated the capability of ORCHIDEE to simulate a variety of post-disturbance forest dynamics observed in empirical studies. Through an array of simulation experiments across various climatic conditions and windthrow intensities, the model was tested for its sensitivity to climate, initial disturbance, and selected parameter values. The results of these tests indicated that with a single set of parameters, ORCHIDEE outputs spanned the range of observed dynamics. Additional tests highlighted the substantial impact of incorporating Ips typographus outbreaks on carbon dynamics. Notably, the study revealed that modeling abrupt mortality events as opposed to a continuous mortality framework provides new insights into the short-term carbon sequestration potential of forests under disturbance regimes by showing that the continuous mortality framework tends to overestimate the carbon sink capacity of forests in the 20- to 50-year range in ecosystems under high disturbance pressure compared to scenarios with abrupt mortality events. This model enhancement underscores the critical need to include disturbance dynamics in land surface models to refine predictions of forest carbon dynamics in a changing climate. [ABSTRACT FROM AUTHOR]

Integrating Light Detection And Ranging (LiDAR) and Hyperspectral Imaging (HSI) enhances the assessment of tropical forest degradation and regeneration, which is crucial for conservation and climate mitigation strategies. This study optimized procedures using combined airborne LiDAR, HSI data, and machine learning algorithms across 12 sites in the Brazilian Amazon, covering various environmental and anthropogenic conditions. Four forest classes (undisturbed, degraded, and two stages of second-growth) were identified using Landsat time series (1984–2017) and auxiliary data. Metrics from 600 samples were analyzed with three classifiers: Random Forest, Stochastic Gradient Boosting, and Support Vector Machine. The combination of LiDAR and HSI data improved classification accuracy by up to 12% compared with single data sources. The most decisive metrics were LiDAR-based upper canopy cover and HSI-based absorption bands in the near-infrared and shortwave infrared. LiDAR produced significantly fewer errors for discriminating second-growth from old-growth forests, while HSI had better performance to discriminate degraded from undisturbed forests. HSI-only models performed similarly to LiDAR-only models (mean F1 of about 75% for both data sources). The results highlight the potential of integrating LiDAR and HSI data to improve our understanding of forest dynamics in the context of nature-based solutions to mitigate climate change impacts. [ABSTRACT FROM AUTHOR]

The results of the dynamic simulation of organic matter stocks in forest soils are discussed from the point of a predictive assessment of carbon sink depending on forest site types and forest management regimes. The biological cycle in the "soil–forest stand" system was simulated with FORRUS-S, Romul_Hum, and SCLISS simulation models. Computational experiments were carried out for three forest enterprises and a nature reserve located in the Republic of Karelia and in Nizhni Novgorod, Moscow, and Bryansk oblasts, which corresponds to a gradient of zonal conditions from the middle taiga to the broadleaved forest subzone. Forest survey data available for all study objects were used to simulate the long-term (100 years) forest dynamics. Calculations of soil Corg pools were carried out separately for each forest taxation area using the corresponding characteristics of the forest stand (mean height, diameter, basal area, growing stock) and soil (Corg and Ntot contents in the forest floor and mineral soil) as initial data, which made it possible to take into account the spatial variability of forest conditions and successional change of species in the resulting area-based estimates of soil carbon sink. Under the nature reserve regime, the mean increase in soil stock of organic matter by 35–80 t C/ha compared to the initial values is predicted for all territories over 100 years. Felling practices of varying intensity reduce the possible Corg sink into forest soils by an average of 30–50 t/ha compared to the reserve regime. Regional features of the dynamics of organic matter are manifested in different ratios of carbon accumulation in organic and organomineral soil horizons. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Unmanned aerial vehicle (UAV) imagery highlights the extent of illegal deforestation in protected areas for the biodiverse humid forest of central Madagascar. The ultra‐high‐resolution (<10‐cm pixel) images enable the creation of detailed forest 3D base maps and provide the means to quantify forest stand losses. To help communities safeguard their forests, local non‐governmental organisations can use UAV maps in combination with weekly deforestation alerts to facilitate an immediate on‐ground response that significantly restricts illegal activity. Integrating ultra‐high‐resolution UAV mapping and coarse‐resolution freely available satellite imagery should have much wider applications in Madagascar and the humid tropics for community‐based conservation. Summary: This study of the Ambohimahamasina humid forest shows that small UAVs offer a detailed (<10‐cm pixel), rapid and cost‐effective solution to provide maps of detailed deforestation patterns not visible in satellite imagery.Calculating forest extent and volume are valuable ways to rapidly assess forest losses and prioritise areas for ground patrols. The use of 3‐dimensional measurements for above ground carbon estimates indicate how, in the future, these metrics could be used to calculate carbon payments for conservation programs.By combining UAV and free satellite imagery, an effective alert system has been developed that supports community initiatives in the protection of their natural forest resources.The wealth of ultra‐high‐resolution UAV data collected in this study provides insights into forest dynamics, supports local community forest management, and has the potential to measure the value of the forest. [ABSTRACT FROM AUTHOR]

Understanding the variation of soil physical properties in relation to land use and elevation is essential for modeling soil-landscape relationships and sustainable land management. Hence, this study investigates the spatio-temporal variability of soil physical properties in a lower Himalayan watershed, where agriculture, forest, and grasslands are dominant. Samples from 104 sites in a 422 km2 watershed were collected using a gridded sampling scheme (2 km × 2 km resolution) over 57 weeks. Spatial patterns were analyzed using the Kriging technique, and Spearman rank correlation was employed to identify landform-dependent correlations between soil properties and elevation. The interdependence of the properties was detected using principal component analysis (PCA), while the random forest (RF) approach explored the factors influencing electrical conductivity (EC), organic content (OC), soil temperature (ST), and soil moisture (SM). The results revealed that forest landforms have higher coarser fractions (40%) compared to other landforms, while grasslands have higher soil fines (66%). A positive correlation was observed for elevation with sand content (0.15*), organic content (0.42*), and specific gravity (0.03), while a negative correlation was observed for silt (0.10), clay (0.21*), bulk density (0.52*), electrical conductivity (0.41*), soil moisture (0.28*), and temperature (0.31*). Elevation, soil texture, and specific gravity were identified as critical controls for EC, OC, ST, and SM, emphasizing the importance of soil properties, especially elevation and texture, in shaping spatial distributions. These findings contribute to creating a high-resolution regional inventory for effective land use management, adaptation to climate change, and improved livelihood, specifically for mountain people. [ABSTRACT FROM AUTHOR]

The increasing rates of forest cover change and heightened vulnerability to deforestation present significant environmental challenges in Northeast India. This study investigates the dynamics of forest cover change and susceptibility to deforestation in this region from 2001 to 2021, utilizing data from the Hansen Global Forest Change (HGFC) product on the Google Earth Engine (GEE) platform. A suite of multicriteria decision-making (MCDM) models—including VlseKriterijumska optimizacija I Kompromisno Resenje (VIKOR), Simple Additive Weighting (SAW), Evaluation Based on Distance from Average Solution (EDAS), and Weighted Aggregates Sum Product Assessment (WASPAS)—was employed to assess changes in forest cover and deforestation susceptibility across varied zones. Multicollinearity tests confirmed the relevance of the factors influencing deforestation. Statistical validations, such as the Wilcoxon Signed Ranks Test, underscored the models' robustness, revealing statistically significant outcomes. Additionally, Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) analysis demonstrated the superior fit of the VIKOR model (AUC = 0.938) compared to SAW (AUC = 0.901), EDAS (AUC = 0.895), and WASPAS (AUC = 0.864) in predicting current deforestation susceptibility. Validation affirmed the reliability of all MCDM methods, with VIKOR displaying high sensitivity (True Positive Rate, TPR = 0.878) and optimal AUC (0.938). Correlation analyses among the models identified significant inter-relationships, notably a positive correlation between EDAS and SAW, and a negative correlation between VIKOR and SAW. The regions of Assam, Nagaland, Mizoram, and Arunachal Pradesh were identified as experiencing significant forest cover loss, indicating a pronounced susceptibility to future deforestation. These findings underscore the need for immediate intervention to address this critical environmental issue. [ABSTRACT FROM AUTHOR]

Forest fire dynamics are expected to alter due to climate change. Despite the projected increase in precipitation, rising temperatures will amplify forest fire risk from the present to the end of the century. Here, we analysed changes in fire season, the number of fires, and burnt area in Fennoscandia from 1951 to 2100. Regional simulations from the JSBACH–SPITFIRE ecosystem model (where SPITFIRE stands for SPread and InTensity of FIRE) were performed under two climate change forcing scenarios (Representative Concentration Pathway (RCP) 4.5 and RCP 8.5) and three global climate driver models (CanESM2, CNRM-CM5, and MIROC5) with a 0.5° resolution. Simulations were forced by downscaled and bias-corrected EURO-CORDEX data. Generally, as a consequence of the projected longer fire season and drier fuel, the probability of fires is projected to increase. However, changes in fire season, the number of fires, and burnt area are highly dependent on climate projections and location. The fire season is estimated to increase on average from 20 ± 7 to 52 ± 12 d, starting from 10 ± 9 to 23 ± 11 d earlier and ending from 10 ± 10 to 30 ± 16 d later, compared to the reference period (1981–2010), by the end of the century (2071–2100). The results for Finland indicate a change in the number of fires, ranging from -7 ± 4 % to 98 ± 56 %, and a change in burnt area, ranging from -19 ± 24 % to 87 ± 42 %. These findings contribute to a better understanding of potential changes in the future fire seasons of northern Europe. [ABSTRACT FROM AUTHOR]

The Hyrcanian forests have a diverse fauna and flora with many endemic species of plants and animals. The Iranian long-legged wood frog, Rana pseudodalmatina, is one of the endemic species in this forest. The phylogenetic and morphologic analysis indicates the existence of the western and the eastern clades in R. pseudodalmatina. Differences in the life history of the same species can attributed to different habitat quality or climate. The probability of encountering an Iranian long-legged wood frog, R. pseudodalmatina in the western half of the Hyrcanian forests of the southern shores of the Caspian Sea is much higher than in the forests of the eastern sea. This increase in the detection probability can be attributed to higher precipitation levels in the West of the Hyrcanian forests compared to the East. I observed that the Eastern populations tend to have larger sizes. In addition, the individuals of the western branch have a lower mean age (5.29 ± 0.74 years) than the eastern ones (8.36 ± 0.08 years). According to our results, females were larger (54.64 ± 0.53 mm) and older (7.68 ± 0.24 years) than males (48.13 ± 0.39 mm; 5.89 ± 0.39 years) in both eastern and western clades. So, the difference has been attributed to the variation in precipitation between the East and West of the sea, leading to different environmental conditions for R. pseudodalmatina. Hence, any conservation planning to protect this native species of the Hyrcanian forests must consider inter and intra-population differences in the East and West of the Hyrcanian forests. [ABSTRACT FROM AUTHOR]

New forests on former agricultural land originate either from natural regeneration or active restoration. Previous research has compared biodiversity of naturally regenerated stands (NR) and plantations (PL), however, whether understory succession towards natural forests depends on stand type remains unknown. In this study, we used data from two monitorings on permanent plots (2011 and 2019) in PL (n = 11) and NR (n = 11) birch stands in Estonia to highlight successional changes in herb and bryophyte communities together with environmental changes. We further evaluated whether stand type influenced the recovery of forest specialists. We found an increase in tree growth characteristics, soil phosphorus and nitrogen content, no change in light conditions and a decrease in soil pH in both stand types. The amount of litter and deadwood was higher in NR in 2011. Herb richness increased from 123 to 130 and the number of bryophytes from 43 to 62. Stand types shared 50% of herb species in 2011 and 2019, while the fraction of shared bryophytes increased from 37.2 to 56.5%. We observed an increase of forest specialists and a decrease in light-demanding species (based on indicator value for light) in both stand types. Bryophyte cover and richness increased and species compositions of stand types converged. However, the number of bryophytes was significantly higher in NR plots indicating the significance of deadwood as growth substrate. We conclude that the recovery of forest understory followed similar successional pathways in PL and NR. [ABSTRACT FROM AUTHOR]

Warming and more variable climates threaten to upend historical tree ranges, climatic sensitivity, and vigor. In western North America, the species Picea engelmannii var. engelmannii Parry ex Engelmann (Engelmann spruce) and Picea pungens Engelmann (Colorado blue spruce) are widespread spruce that act as foundational species in their montane to subalpine habitats. However, there is currently a lack of knowledge on P. pungens climatic responses, and how it differs from P. engelmannii. To address this gap, we assessed the climatic sensitivity and correlates of tree growth in a co‐occurring old‐growth stand of P. engelmannii and P. pungens, at high elevation in southern Utah, USA. We report the putative oldest cross‐dated P. pungens, with 457 rings, and sampled multiple P. pungens >400 years old. Both Picea populations had strongly positive growth responses to May–July precipitation and negative responses to maximum May–July temperature. Notably, October in the previous year had the strongest correlation with growth for both Picea species. Neither population exhibited signs of directional changes in climate–growth responses. Spectral analysis identified peaks associated with El Niño–Southern Oscillation at 3–4 years and quasi‐decadal oscillations (18–20 years) in both species. Cumulatively, our results highlight the growth–climate relationships of two frequently understudied subalpine tree species. In particular, P. pungens may warrant further study across its range and identification of other ancient populations. [ABSTRACT FROM AUTHOR]

Compound drought and heat events (CDHEs) and forest cover change influence regional forest carbon dynamics. Changes in regional vegetation biomass and soil carbon storage induced by forest cover change often exhibit considerable uncertainty, and previous research on the impacts of CDHEs on forest carbon dynamics is limited. To accurately quantify the specific effects of forest cover change and CDHEs on forest carbon dynamics in different regions, we employed a combined algorithm of the Carnegie–Ames–Stanford Approach (CASA) and bookkeeping empirical models to examine the impact of regional forest cover changes on forest carbon dynamics during 2000–2022 in Nanjing and Shaoguan, Southern China. Using the Geographical Detector model, we then analyzed the effects of CDHEs on forest carbon dynamics. Next, we used the photosynthesis equation and the optimal response time of forests to drought (heat) events to calculate the changes in forest carbon sequestration caused by CDHEs in both regions during 2000–2022. The results indicated that afforestation and deforestation led to +0.269 TgC and +1.509 TgC of carbon sequestration and 0.491 TgC and 2.802 TgC of carbon emissions in Nanjing and Shaoguan, respectively. The overall effects of CDHEs on the change in forest carbon sequestration were manifested as net carbon loss. In Nanjing, the net carbon loss caused by CDHEs (0.186 TgC) was lower than the loss due to forest cover change (0.222 TgC). In Shaoguan, the net forest carbon loss caused by CDHEs (3.219 TgC) was much more significant than that caused by forest cover change (1.293 TgC). This study demonstrated that forest carbon dynamics are dominated by different factors in different regions, which provides a scientific basis for local governments to formulate targeted forest management policies. [ABSTRACT FROM AUTHOR]

Water environment quality is profoundly driven by a series of landscape characteristics. However, current knowledge is limited to the independent response of water quality to single landscape elements; this has led to poor knowledge of the potential role of structural coupling within landscapes in driving water quality changes, especially in those agroforestry-mixed mountainous watersheds with highly embedded forest-clustered landscapes and abundant headstreams. Given this fact, this study aims to evaluate whether and how the source–sink coupling structure of forest-clustered landscapes systematically drives headstream quality dynamics. We first systematically assessed the association pattern of source and sink structures within forest-clustered landscapes, and then innovatively proposed and constructed a functional framework of source–sink coupling structure of landscapes across 112 agroforestry-mixed mountainous sub-watersheds in Chongqing, China. On this basis, we further evaluated the driving pattern and predictive performance of the source–sink coupling structure of landscapes behind headstream quality dynamics. We report three findings: (1) headstream quality varied across agroforestry-mixed sub-watersheds, mapping out the source–sink structures and functions of landscapes; (2) there was significant functional coordination between source–sink structures of the forest-clustered landscapes, which significantly drove headstream quality dynamics; (3) the structural positioning and differences of the forest-clustered landscapes along the multivariate functional axes directly corresponded to and predicted headstream quality status. These findings together highlight a key logic that the response of water quality dynamics to landscapes is essentially that to the functional coupling between the source–sink structures of landscapes, rather than the simple combination of a single landscape contribution. This is the first study on the landscape–runoff association from the perspective of source–sink structural coupling, which helps to deepen understanding of the correlation mechanism between water dynamics and landscape systems, and provides a new functional dimension to the development of future landscape ecological management strategies from a local to a global scale. [ABSTRACT FROM AUTHOR]

Forests are widely distributed in terrestrial ecosystems, covering about one-third of the global land area. They play a key role in sequestering carbon, releasing oxygen, mitigating climate change, and maintaining ecosystem balance. The ecology of the Tibetan Plateau is very fragile, but the impact of environmental change on regional forest ecosystems is not yet clear. Located in the Eastern Tibetan Plateau, the Shaluli Mountain has the richest biodiversity and the widest distribution of forests on the Tibetan Plateau. Assessing the dynamics of forest change is the basis for correctly formulating forest management measures, and is important for regional biodiversity conservation. However, traditional field surveys have the shortcomings of high cost, being time-consuming, and having poor regional coverage in forest dynamics monitoring. Remote sensing methods can make up for these shortcomings. Therefore, in this study, satellite remote sensing images were used to extract forest information from 2000 to 2020 in Shaluli Mountain, and the main drivers of forest change were analyzed with full consideration of the Spatially Stratified Heterogeneity (SSH) of environmental factors. The results found that the forest area increased from 23,144.20 km2 in 2000 to 28,429.53 km2 in 2020, and the average Percentage of Forest Cover (PFC) increased from 19.76% to 21.67%, with significant improvement in forest growth. The annual minimum temperature (TMN), altitude, annual maximum temperature (TMX), and annual precipitation (PRE) were the main driving factors of forest change, with an average driving power (q-value) of 0.4877, 0.2706, 0.2342, and 0.2244, and TMN was the primary limiting factor for forest growth. In addition, the driving power of all environmental factors on forest change increased from 2000 to 2020. The results of this study can provide a basis for the development of forest management strategies, and provide reference materials for regional biodiversity conservation. [ABSTRACT FROM AUTHOR]