The World’s forests play a crucial role in environmental, social and economic well-being, but they are under threat from deforestation, climate change and atmospheric pollution. Various intergovernmental bodies since the 1992 ‘Earth’ Summit (UNCED) have used principles, criteria and indicators (PC&I) to evaluate sustainable development and sustainable forest management (SFM) in particular. The financial world has been reluctant to invest in SFM, however, as it cannot be easily simplified and is inherently risky due to the dynamics of nature and external shocks, such as forest fires, storms or draughts. Nevertheless, a range of economic, social, environmental and governance initiatives for evaluating, or reporting on, sustainable forest finance (SFF) have been developed over the years. Some of these relate to the economic aspects of forest management, but formal linkages between SFF and SFM are still being forged. The authors place a selection of these initiatives into an integrating framework to provide a more wholistic approach to determining, and evaluating, what constitutes SFF. The results of this integration exercise reveal a strong preference towards environmental and social criteria, but some elements, notably economic sustainability, are less well featured. The shortcomings and challenges of this preliminary study are discussed. The authors conclude more work is needed to help investors and stakeholders overcome the current complexity and confusion in the world of SFF, and see the wood for the trees.

Species' traits and environmental conditions determine the abundance of tree species across the globe. The extent to which traits of dominant and rare tree species differ remains untested across a broad environmental range, limiting our understanding of how species traits and the environment shape forest functional composition. We use a global dataset of tree composition of >22,000 forest plots and 11 traits of 1663 tree species to ask how locally dominant and rare species differ in their trait values, and how these differences are driven by climatic gradients in temperature and water availability in forest biomes across the globe. We find three consistent trait differences between locally dominant and rare species across all biomes; dominant species are taller, have softer wood and higher loading on the multivariate stem strategy axis (related to narrow tracheids and thick bark). The difference between traits of dominant and rare species is more strongly driven by temperature compared to water availability, as temperature might affect a larger number of traits. Therefore, climate change driven global temperature rise may have a strong effect on trait differences between dominant and rare tree species and may lead to changes in species abundances and therefore strong community reassembly.

The density of wood is a key indicator of the carbon investment strategies of trees, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here we analyse information from 1.1million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical forests being up to 30% denser than that in boreal forests. In both angiosperms and gymnosperms, hydrothermal conditions represented by annual mean temperature and soil moisture emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.

The density of wood is a key indicator of trees’ carbon investment strategies, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here, we analyze information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially-explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical dry forests being up to twice as dense as that in boreal forests. In both angiosperms and gymnosperms, temperature and water availability emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.

In this forest perspectives paper, we explore issues and concepts involved in the enhancement of regional monitoring frameworks for reporting on forest disturbances and damages. First, we consider the different meanings of “forest disturbance” and “forest damage,” terms that are often used interchangeably but have important differences in meaning and management implications. Human expectations, goals and concerns underlie both terms, especially forest damage, and they condition the data-gathering efforts and interpretations of resulting information. Accordingly, we also address the overall motivations for reporting forest disturbances and damages, the potentially impacted human expectations, and the general categories of impact and response. Next, we present some general observations on the ecological processes underlying forest disturbances and forest damages and the approaches used to measure them, noting the following challenges these processes pose for clear and consistent reporting across space and time: complexity of disturbance processes; attributing causality and distinguishing between proximate, intermediate and ultimate causes; spatial and temporal discontinuities; measurement protocol variations between countries. Both ecological processes and their related measurement techniques are particularistic, involving various and specific measurement techniques and protocols, and they do not always conform to conceptual generalizations. We conclude with a discussion on bridging the gap between concept and practical application of disturbance and damage monitoring and reporting. Despite challenges in aggregating diverse data on forest disturbances, doing so is crucial for improving scientific understanding, policy-making, and environmental management on regional and global scales.

Forests are considered an important component on the road to climate neutrality. Together with technical and other nature-based solutions, they should help to compensate for unavoidable residual emissions. Forests are seen primarily as a carbon sink, removing CO2 from the atmosphere through biomass growth. The desire to increase the sink capacity of forests to achieve climate neutrality suggests the removal of C through timber harvesting. Without timber harvesting, wood-based products would have to be replaced by products based on other raw materials, which generally cause higher emissions during production. The goal of climate neutrality is thus jeopardized. Forests can make a much greater contribution to climate neutrality by harvesting their wood and supplying it to low-emission processing operations, and by sequestering the carbon contained in the biomass used in wood products over the long term.

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling.

Whether traditional and emerging innovative wood products and their applications are in fact environmentally friendlier than non-wood products has to be evaluated on a case-by-case basis. Therefore, Life Cycle Assessment (LCA) as a methodological framework to assess environmental impacts of products is introduced and applied to wood and wood-based products. For investigating not only impacts of single product systems but also consequential effects of changing utilization patterns, combining LCA with Material Flow Analysis (MFA) is a useful approach, which also considers shifts of product flows on a regional level. The inherent properties of wood as a bio-based and renewable material, which lead to some specific considerations in the product category rules, are discussed and exemplified by showcasing the main areas of LCA application along the forest-wood value chains. The provision of traceable information about the forest management practices and the chain-of-custody of the wood based materials as important prerequisites for an environmental assessment are discussed. The environmental aspects and implications of wood usage are illustrated for the relevant wood-based products and utilization schemes, from building products to energy use. The contributions of forests and harvested wood products to climate change mitigation are described. Further, examples for the assessment of wood products by resource efficiency and eco-efficiency analysis are presented, and specific focus is given on end-of-life processes and the evaluation of wood cascading options.

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5-7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system 1 . Remote-sensing estimates to quantify carbon losses from global forests 2 – 5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced 6 and satellite-derived approaches 2 , 7 , 8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea 2 , 3 , 9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets.

Greenhouse gases (GHG) have extensive environmental effects by trapping heat and causing climate change and air pollution. Land plays a key role in the global cycles of GHG (i.e., carbon dioxide (CO2), methane (CH4), and nitrogen oxide (N2O)), and land use change (LUC) can lead to the release of such gases into the atmosphere or the removal of them from the atmosphere. One of the most common forms of LUC is agricultural land conversion (ALC) where agricultural lands are converted for other uses. This study aimed to review 51 original papers from 1990 to 2020 that investigate the contribution of ALC to GHG emissions from a spatiotemporal perspective using a meta-analysis method. The results of spatiotemporal effects on GHG emissions showed that the effects were significant. The emissions were affected by different continent regions representing the spatial effects. The most significant spatial effect was relevant to African and Asian countries. In addition, the quadratic relationship between ALC and GHG emissions had the highest significant coefficients, showing an upward concave curve. Therefore, increasing ALC to more than 8 % of available land led to increasing GHG emissions during the economic development process. The implications of the current study are important for policymakers from two perspectives. First, to achieve sustainable economic development, policymaking should prevent the conversion of more than 90 % of agricultural land to other uses based on the turning point of the second model. Second, policies to control global GHG emissions should take into account spatial effects (e.g., continental Africa and Asia), which show the highest contribution to GHG emissions.

Soil organic carbon (SOC) plays a crucial role in global carbon cycling. The amount of SOC is influenced by many factors (climate, topography, forest type, forest disturbance, etc.). To investigate this potential effect, we performed a multiple regression model using six different predictor variables in the third national-level forest resource assessment data of Nepal. We found a significant correlation between the SOC and altitude (r = 0.76) followed by crown cover and slope. The altitude alone explains r(2) = 58 percent of the variability of the SOC and shows an increasing rate of change of SOC with the increase of altitude. Altitude was identified as a suitable predictor of SOC for large areas with high altitudinal variation followed by crown cover and slope. Increasing amounts of SOC with increasing altitude shows the significance of high-altitude forests in the perspective of climate change mitigation. Altitude, a proxy of temperature, provides insights into the influence of changing temperature patterns on SOC due to future climate change. Further study on forest types and SOC along the altitudinal gradient in Nepal is recommended to deal with the climate change problem in the future.

Forest management recognizes the selection of tree species as an essential aspect of climate change adaptation. Uncertainties exist, however, regarding the assessment of average and extreme climatic conditions to which tree species can adapt. This study discusses the feasibility of analyzing oak ( Quercus spp.) tree rings from urban habitats as a proxy for projected climate change effects on urban and forest tree stands. Therefore, the influence of climate on tree growth is compared between trees growing in forests and urban environments. Tree-ring samples from urban areas and a forest site were collected in Hamburg, northern Germany. Tree-ring analysis was used to investigate the correlation between temperature and precipitation patterns and oak growth. Pointer year analysis was applied to explore the causes of variations in ring width. The impact of drought events was examined by Superposed Epoch Analysis. The results indicate that urban trees are more vulnerable to drought stress than forest trees. Oak growth in both sites shows a significant correlation with climatic conditions in summer, while forest oak growth is also affected by winter temperatures. Pointer year analysis indicates drought as the main driver of reduced growth. However, no long-term impact of drought years was observed, as both urban and forest oaks showed a fast recovery in growth in the proceeding years. Moreover, the study demonstrates the viability of using urban tree rings for dendroclimatological analysis and offers an approach for tree species selection in urban and forest environments as a contribution to the adaptation of forests to future climate change.

As various political initiatives have set goals to reach net-zero emissions by the mid-21st century, forests will play an important role as a carbon sink for sequestering unavoidable emissions. Forest management can take two approaches by either decreasing harvest and enlarging the forest carbon stock or increasing harvest to increase carbon uptake and create harvested wood products (HWPs). Currently, these two management options seem at odds with seemingly conflicting policy directives being written. We used the BEKLIFUH model to assess six management scenarios based on carbon offset potential taking into consideration forest carbon, HWPs and the material and energetic substitution effects. The results show that while conservation leads to a higher above-ground carbon pool, including HWPs, material and energetic substitution leads to more overall carbon offsets for management scenarios with more timber harvesting. With compromise being possible by selectively conserving old growth forests with a high biodiversity value. In conclusion, if the forest sector decouples GHG reporting from forest management and includes all the secondary effects of timber harvest, this new approach can lead to a different cost–benefit analysis for the choice between harvest vs. conservation. This could result in a paradigm shift to a future where biodiversity and carbon neutrality can coexist.

The determination of the geographical origin of wood can be highly relevant for several reasons: On the one hand, it can help to prevent illegal logging and timber trade, on the other hand, it is of special interest for archaeological artefacts made of wood, as well as for a variety of biological questions. For this reason, different extraction methods were first tested for the analysis of polar and non-polar metabolites using liquid chromatography coupled electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS). A two-phase extraction with chloroform, methanol and water proved to be particularly successful. Subsequently, cedrela (Cedrela odorata) samples from South America were measured to distinguish geographic origin. Using multivariate data analysis, numerous origin-dependent differences could be extracted. The identification of the marker substances indicated that several metabolic pathways were affected by the geographical influences, some of them probably indicating pest infections.

Nature and species conservation often conflict with intensive natural resource or land use. Many protected areas are too small for long-term conservation of viable vertebrate populations, especially in Madagascar, and forests are subject to exploitation for a variety of natural resources. Trying to exclude people from the use of these resources has not been successful during economic, natural, or political crises or when human population growth outruns any development effort. People need economic and other benefits, and conservation measures have to account for these needs. We compiled native and introduced tree, shrub, and herbaceous species used by both people and native vertebrates for three regions, covering the domains of the dry, transitional, and humid forest of Madagascar. We carried out semistructured interviews and group discussions in 12 different villages in each study region in November 2017. People listed 139 utilitarian plant taxa. Our literature search revealed that 72 of these plant species and 13 genera used by people, were also used by 208 different terrestrial vertebrates including 58 lemur species. Application of the Forest Landscape Restoration approach with a combination of exotic and native plant species used by both people and animals could increase the economic value of restored forest habitats for people, thus providing incentives for forest conservation. Plantations of mixed utilitarian trees and shrubs could be integrated into agricultural landscapes. Among land-living vertebrates, lemurs seem to benefit most from this approach. These measures might contribute to a successful array of biodiversity conservation in anthropogenic landscapes.

Silvicultural treatments are a common tool for increasing commercial timber production. Their impact on the growth or mortality of the remaining stand is well researched. This study focuses on the economic aspects of silvicultural treatments in neotropical forests. We have selected liberation treatments and consider them to be investments that are expected to pay for themselves through the additional growth of released trees and corresponding timber prices following a 30-year rotation period. The study is based on empirical data collected on experimental sites of 10 km2 in Belize, Guyana, Suriname, Trinidad and Tobago. To determine the timber price or additional growth required to cover the treatment costs, we used a reverse approach based on net present values. The treatment costs range between US$4.5 and US$8.9 per released tree. The additional growth required per released tree to cover the expenses for silvicultural treatments depends on treatment costs and achievable timber prices and varies from 0.02 to 3.5 m3. Conversely, if a potential increase in growth is assumed, timber prices must be between 34 and 578 US$ m-3 to at least cover the cost of treatments. We found a high sensitivity of profitability related to the additional growth, the timber prices to be achieved, and the discount rate chosen, which significantly increases the financial risk of silvicultural treatments as an investment tool. The decision whether to use silvicultural treatments or not is often solely guided by the expected improvement in tree growth. We, however, show that growth alone is insufficient as a decision criterion. While treatment costs are known when the decision to implement the measures is made, future timber prices and harvesting costs as well as the additional growth actually achieved are subject to uncertainties. These uncertainties have a decisive influence on the economic risk assessment, which is reflected in the choice of the internal interest rate. Our study demonstrates that investments in silvicultural treatments involve a considerable financial risk and that the decision to carry out silvicultural treatments should always be the subject of a thorough investment calculation.