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One-third of global forest is harvested for timber, generating ~US$1.5 trillion annually. High-severity wildfires threaten this timber production. Here we combine global maps of logging activity and stand-replacing wildfires to assess how much timber-producing forest has been lost to wildfire this century, and quantify spatio-temporal changes in annual area lost. Between 2001 and 2021, 18.5–24.7 million hectares of timber-producing forest—an area the size of Great Britain—experienced stand-replacing wildfires, with extensive burning in the western USA and Canada, Siberian Russia, Brazil and Australia. Annual burned area increased significantly throughout the twenty-first century, pointing to substantial wildfire-driven timber losses under increasingly severe climate change. To meet future timber demand, producers must adopt new management strategies and emerging technologies to combat the increasing threat of wildfires.Wildfires have caused widespread and increasingly severe losses within timber-producing forests in recent decades, according to maps of logging activity and wildfires.

The loss of large old trees in many ecosystems around the world poses a threat to ecosystem integrity. Large old trees are among the biggest organisms on Earth. They are keystone structures in forests, woodlands, savannas, agricultural landscapes, and urban areas, playing unique ecological roles not provided by younger, smaller trees. However, populations of large old trees are rapidly declining in many parts of the world, with serious implications for ecosystem integrity and biodiversity.

Aim: Large disturbances increasingly shape the world's forests. Concomitantly, increasing amounts of forest are subject to salvage logging. Understanding and managing the world's forests thus increasingly hinges upon understanding the combined effects of natural disturbance and logging disturbance, including interactions so far unnoticed. Here, we use recent advances in disturbance-interaction theory to disentangle and describe the mechanisms through which natural disturbance (e.g., wildfire, insect outbreak or windstorm) can interact with anthropogenic disturbance (logging) to produce unanticipated effects. We also explore to what extent such interactions have been addressed in empirical research globally. Insights: First, many ecological responses to salvage logging likely result from interaction modifications—i.e., from non-additive effects–between natural disturbance and logging. However, based on a systematic review encompassing 209 relevant papers, we found that interaction modifications have been largely neglected. Second, salvage logging constitutes an interaction chain because natural disturbances increase the likelihood, intensity and extent of subsequent logging disturbance due to complex socio-ecological interactions. Both interaction modifications and interaction chains can be driven by nonlinear responses to the severity of each disturbance. We show that, whereas many of the effects of salvage logging likely arise from the multiple kinds of disturbance interactions between natural disturbance and logging, they have mostly been overlooked in research to date. Conclusions: Interactions between natural disturbance and logging imply that increasing disturbances will produce even more disturbance, and with unknown characteristics and consequences. Disentangling the pathways producing disturbance interactions is thus crucial to guide management and policy regarding naturally disturbed forests.

Landscape modification and habitat fragmentation are key drivers of global species loss. Their effects may be understood by focusing on: (1) individual species and the processes threatening them, and (2) human-perceived landscape patterns and their correlation with species and assemblages. Individual species may decline as a result of interacting exogenous and endogenous threats, including habitat loss, habitat degradation, habitat isolation, changes in the biology, behaviour, and interactions of species, as well as additional, stochastic threats. Human-perceived landscape patterns that are frequently correlated with species assemblages include the amount and structure of native vegetation, the prevalence of anthropogenic edges, the degree of landscape connectivity, and the structure and heterogeneity of modified areas. Extinction cascades are particularly likely to occur in landscapes with low native vegetation cover, low landscape connectivity, degraded native vegetation and intensive land use in modified areas, especially if keystone species or entire functional groups of species are lost. This review (1) demonstrates that species-oriented and pattern-oriented approaches to understanding the ecology of modified landscapes are highly complementary, (2) clarifies the links between a wide range of interconnected themes, and (3) provides clear and consistent terminology. Tangible research and management priorities are outlined that are likely to benefit the conservation of native species in modified landscapes around the world.

Newly discovered species are often threatened with extinction but in many cases have received limited conservation effort. To guide future conservation, it is important to determine the extinction risk of newly described species. Here, we test how time since formal description of a species is linked to its threat status to obtain a better insight into the possible threat status of newly described species and as yet undescribed species. We compiled IUCN Red List data for 53,808 species from five vertebrate groups described since 1758. Extinction risk for more recently described species has increased significantly over time; the proportion of threatened species among newly described species has increased from 11.9% for species described between 1758 and 1767 to 30.0% for those described between 2011 and 2020. Based on projections from our analysis, this could further increase to 47.1% by 2050. The pattern is consistent across vertebrate taxonomic groups and biomes. Current species extinction rates estimated from data of all known species are therefore highly likely to be underestimated. Intensive fieldwork to boost discovery of new species and immediate conservation action for newly described species, especially in tropical areas, is urgently required.

A key part of native forest management in designated wood production areas is identifying locations which must be exempt from logging. Forest laws, government regulations, and codes of practice specify where logging is and is not permitted. Assessing compliance with these regulations is critical but can be expensive and time consuming, especially if it entails field measurements. In some cases, spatial data products may help reduce the costs and increase the transparency of assessing compliance. However, different spatial products can vary in their accuracy and resolution, leading to uncertainty in forest management. We present the results of a detailed case study investigating the compliance of logging operations with laws preventing cutting on slopes exceeding 30°. We focused on two designated water catchments in the Australian State of Victoria which supply water to the city of Melbourne. We compared slopes that had been logged on steep terrain using spatial data based on a Digital Elevation Model (DEM) derived from LiDAR, a 1 arc second DEM derived from the Shuttle Radar Topography Mission, and a Digital Terrain Model (DTM) with a resolution of 10m. While our analyses revealed differences in slope measurements among the different spatial products, all three datasets (and the on-site slope measurements) estimated the occurrence of widespread logging of forests on slopes >30° in both water catchments. We found the lowest resolution Shuttle Radar Topography Mission DEM underestimated the steepness of slopes, whilst the DTM was variable in its estimates. As expected, the LiDAR generated slope calculations provided the best fit with on-site measurements. Our study demonstrates the value of spatial data products in assessing compliance with logging laws and codes of practice. We suggest that LiDAR DEMs, and DTMs also can be useful in proactive forest planning and management by helping better identify which areas should be exempt from cutting before logging operations commence.

Two billion ha have been identified globally for forest restoration. Our meta-analysis encompassing 221 study landscapes worldwide reveals forest restoration enhances biodiversity by 15&-84% and vegetation structure by 36&-77%, compared with degraded ecosystems. For the first time, we identify the main ecological drivers of forest restoration success (defined as a return to a reference condition, that is, old-growth forest) at both the local and landscape scale. These are as follows: the time elapsed since restoration began, disturbance type and landscape context. The time elapsed since restoration began strongly drives restoration success in secondary forests, but not in selectively logged forests (which are more ecologically similar to reference systems). Landscape restoration will be most successful when previous disturbance is less intensive and habitat is less fragmented in the landscape. Restoration does not result in full recovery of biodiversity and vegetation structure, but can complement old-growth forests if there is sufficient time for ecological succession.

Soils are a fundamental component of terrestrial ecosystems, and play key roles in biogeochemical cycles and the ecology of microbial, plant and animal communities. Global increases in the intensity and frequency of ecological disturbances are driving major changes in the structure and function of forest ecosystems, yet little is known about the long-term impacts of disturbance on soils. Here we show that natural disturbance (fire) and human disturbances (clearcut logging and post-fire salvage logging) can significantly alter the composition of forest soils for far longer than previously recognized. Using extensive sampling across a multi-century chronosequence in some of the tallest and most carbon-dense forests worldwide (southern Australian, mountain ash (Eucalyptus regnans) forests), we provide compelling evidence that disturbance impacts on soils are evident up to least eight decades after disturbance, and potentially much longer. Relative to long-undisturbed forest (167 years old), sites subject to multiple fires, clearcut logging or salvage logging were characterized by soils with significantly lower values of a range of ecologically important measures at multiple depths, including available phosphorus and nitrate. Disturbance impacts on soils were most pronounced on sites subject to compounding perturbations, such as multiple fires and clearcut logging. Long-lasting impacts of disturbance on soil can have major ecological and functional implications.Fires and logging alter soil composition and result in a significant reduction of soil nutrients that lasts for decades after the disturbance, suggests an analysis of soil samples across a multi-century sequence in mountain ash forests.

Global sustainability agendas focus primarily on halting deforestation, yet the biodiversity crisis resulting from the degradation of remaining forests is going largely unnoticed. Forest degradation occurs through the loss of key ecological structures, such as dying trees and deadwood, even in the absence of deforestation. One of the main drivers of forest degradation is limited awareness by policy makers and the public on the importance of these structures for supporting forest biodiversity and ecosystem function. Here, we outline management strategies to protect forest health and biodiversity by maintaining and promoting deadwood, and propose environmental education initiatives to improve the general awareness of the importance of deadwood. Finally, we call for major reforms to forest management to maintain and restore deadwood; large, old trees; and other key ecological structures.

1. Scattered trees are thought to be keystone structures for biodiversity in landscapes world-wide. However, such trees have been largely neglected by researchers and their importance for biodiversity remains unclear. 2. We completed a global meta-analysis to quantify relationships between scattered trees and the species richness, abundance and composition of vertebrates, arthropods and plants. First, we tested whether areas near scattered trees support higher levels of species richness and abundance than nearby open areas. Second, we compared levels of species richness and abundance in matrix areas with scattered trees and areas embedded within nearby habitat patches. We also compared the composition of biological communities inhabiting habitat patches, open areas and areas with scattered trees. 3. A total of 62 studies contained suitable data for our quantitative analyses. The local abundance of arthropods, vertebrates and woody plants was 60%-430% greater and overall species richness was 50%-100% higher in areas with scattered trees than in open areas. Conversely, for herbaceous plants, there was no consistent relationship between species abundance and the occurrence of scattered trees, although species richness was, on average, 43% lower. 4. The abundance and richness of all taxonomic groups was similar in matrix areas supporting scattered trees and habitat patches, although the species richness of epiphytes was, on average, 50% higher in habitat patches. Communities inhabiting habitat patches were more similar in composition to the communities inhabiting areas with scattered trees, and less similar to the communities of open areas. 5. Synthesis and applications. Areas with scattered trees support greater levels of bio-diversity than open areas, as well as communities that are more similar to those inhabiting habitat patches. Scattered trees can be regarded as keystone structures for vertebrates, arthropods and terrestrial plants in landscapes world-wide. The maintenance of scattered trees may be compatible with livestock grazing in some agricultural landscapes. Greater management effort and targeted, long-term policies are needed to retain or re-establish scattered trees in many farming landscapes in both forest and non-forest biomes around the world.