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A third of the forest area in Central Africa has been granted to logging companies. Logging is highly selective in the region, with an average of 0.7–4.0 trees harvested per ha, but its direct impact on forest structure and the spatial variation of this impact remain understudied. Here, we investigated the direct impact of logging on forest structure, we related this impact to logging intensity and canopy opening. We compiled unique datasets collecting field measurements and aerial observations in four FSC certified concessions. Our data includes pre- and post-logging inventory of forest plots covering 38 ha, records of over 6000 harvested trees, and drone RGB images covering over 6000 ha. In average, logging activities reduced forest above-ground biomass by 8.8%, stem density by 6.5%, basal-area by 8.5% and canopy cover by 4.4%. Strong relationships were found between the reduction in biomass, stem density, or basal area with logging intensity, canopy opening and the number and volume of harvested trees (relative root mean squared error (rRMSE) between 0.128 and 0.164). Additionally, we demonstrated that canopy opening can be a good indicator to monitor and upscale logging intensity (rRMSE between 0.0005 and 0.0022). This study is the first covering extensive inventory plots and uninhabited aerial vehicle images before and after logging in different locations in Central Africa, providing a valuable reference to evaluate the impact of logging on forest structure. It demonstrates how canopy opening can be used to estimate measurements usually collected in the field and provides to the remote sensing community a unique dataset that will help improving monitoring systems (Dupuis et al 2024 (available at: https://hdl.handle.net/2268/323683)). These findings also have significant implications to control and manage logging activities, especially for certification standards, forest administrations, and European regulations.

While habitat loss and hunting remain the major drivers of biodiversity declines, sublethal disturbances, such as human presence, recreation, and noise also impact wildlife. In response, wildlife often adjust their spatiotemporal behaviors. This study assesses how terrestrial wildlife responds to sublethal disturbances associated with sustainable logging activities. Using camera traps, we conducted a 2‐year continuous survey of two logging compartments within an active, sustainably logged forest reserve in central Sabah, Malaysian Borneo. The survey encompassed periods before, during, and after logging activities, and we obtained daily felling data. Using generalized linear mixed models, we assessed the impact of logging on the spatiotemporal activity of 10 terrestrial mammal and galliform species, considering spatial factors like logging intensity and distance from logging activity, and temporal factors such as days since logging. Four species had a significant and strong response to logging intensity, with varied directions of effect. Only for one species, the response to logging intensity was mediated by time since logging. Though only descriptive, we found no evidence of diel activity shifts, and, for all other species detected during our survey, general patterns in the number of records across each logging period were mixed. Our results highlight the variable and species‐specific responses to logging activity. At a local scale, many species exhibit resilience in their spatiotemporal activity patterns, but for affected species, the effects of logging appear to linger over time. The overall limited response could be due to the relatively low disturbance nature of reduced‐impact logging.

Illegal logging is an important driver of tropical forest loss. A wide range of organizations and interested parties wish to track selective logging activities and verify logging intensities as reported by timber companies. Recently, free availability of 10 m scale optical and radar Sentinel data has resulted in several satellite-based alert systems that can detect increasingly small-scale forest disturbances in near-real time. This paper provides insight in the usability of satellite-based forest disturbance alerts to track selective logging in tropical forests. We derive the area of tree cover loss from expert interpretations of monthly PlanetScope mosaics and assess the relationship with the RAdar for Detecting Deforestation (RADD) alerts across 50 logging sites in the Congo Basin. We do this separately for various aggregation levels, and for tree cover loss from felling and skidding, and logging roads. A strong linear relationship between the alerts and visually identified tree cover loss indicates that with dense time series satellite data at 10 m scale, the area of tree cover loss in logging concessions can be accurately estimated. We demonstrate how the observed relationship can be used to improve near-real time tree cover loss estimates based on the RADD alerts. However, users should be aware that the reliability of estimations is relatively low in areas with few disturbances. In addition, a trade-off between aggregation level and accuracy requires careful consideration. An important challenge regarding remote verification of logging activities remains: as opposed to tree cover loss area, logging volumes cannot yet be directly observed by satellites. We discuss ways forward towards satellite-based assessment of logging volumes at high spatial and temporal detail, which would allow for better remote sensing based verification of reported logging intensities and tracking of illegal activities.

1. Logging is a major driver of tropical forest degradation, with severe impacts on plant richness and composition. Rarely have these effects been considered in terms of their impact on the functional and phylogenetic diversity of understorey plant communities, despite the direct relevance to community reassembly trajectories. Here, we test the effects of logging on functional traits and evolutionary relatedness, over and above effects that can be explained by changes in species richness alone. We hypothesised that strong environmental filtering will result in more clustered (under-dispersed) functional and phylogenetic structures within communities as logging intensity increases. 2. We surveyed understorey plant communities at 180 locations across a logging intensity gradient from primary to repeatedly logged tropical lowland rain forest in Sabah, Malaysia. For the 691 recorded plant taxa, we generated a phylogeny to assess plot-level phylogenetic relatedness. We quantified 10 plant traits known to respond to disturbance and affect ecosystem functioning, and tested the influence of logging on functional and phylogenetic structure. 3. We found no significant effect of forest canopy loss or road configuration on species richness. By contrast, both functional dispersion and phylogenetic dispersion (net relatedness index) showed strong gradients from clustered towards more randomly assembled communities at higher logging intensity, independent of variation in species richness. Moreover, there was a significant nonlinear shift in the trait dispersion relationship above a logging intensity threshold of 65% canopy loss (±17% CL). All functional traits showed significant phylogenetic signals, suggesting broad concordance between functional and phylogenetic dispersion, at least below the logging intensity threshold. 4. Synthesis. We found a strong logging signal in the functional and phylogenetic structure of understorey plant communities, over and above species richness, but this effect was opposite to that predicted. Logging increased, rather than decreased, functional and phylogenetic dispersion in understorey plant communities. This effect was particularly pronounced for functional response traits, which directly link disturbance with plant community reassembly. Our study provides novel insights into the way logging affects understorey plant communities in tropical rain forest and highlights the importance of trait-based approaches to improve our understanding of the broad range of logging-associated impacts.

The logging intensity often does not take into account the spatial heterogeneity of the forest volume of commercial native species in the Brazilian Amazon. This study aims to evaluate the spatio-temporal heterogeneity distribution by assessing logging intensity and its effects on the volumetric stock and abundance of commercial species, with a focus on sustainable management practices. This study was conducted in the Saracá-Taquera National Forest in the Brazilian Amazon. Forest inventory data, elevation, and PlanetScope satellite images were integrated into a geographic information system. The information was aggregated into regular 1-hectare cells for the times before, during, and after logging (t0, t1, and t2). The unsupervised classification algorithm k-means with four clusters was used to analyze heterogeneity. Before logging, areas with higher commercial volumes were distant from water bodies, while areas with lower elevation had lower wood stocks. Logging intensity was generally low, concentrating on a few trees per hectare. Logging in the study area revealed a heterogeneous spatial distribution by intensifying in areas with the highest wood stocks. These results suggest that, in addition to the recommended logging intensity according to legislation, forest heterogeneity should be considered by the manager, promoting adaptive strategies to ensure the conservation of forest resources.

By assessing the short-term impact that various logging intensities have on stand state in middle-aged P. massoniana plantations, this investigation aimed to establish a theoretical foundation to support the judicious management of Pinus massoniana plantations. Five distinct logging intensity categories were delineated (0%, 10%, 20%, 30%, 40%). To construct a robust stand-state evaluation framework, nine representative indicators across the three dimensions of structure, vitality, and diversity were selected. We scrutinized the short-term impacts of logging intensity by employing the unit circle method. The findings revealed that (1) four indicators—stand density, tree health, species composition, and species diversity—exhibited pronounced sensitivity to logging intensity. These four exhibited significant improvements in the short-term post-logging (p < 0.05). Conversely, the indicators of species evenness, diameter distribution, height distribution, tree dominance, and stand growth exhibited a more subdued response to logging intensity. These five necessitated an extended period to begin to improve. (2) The comprehensive evaluation values measuring the stand state of middle-aged P. massoniana plantations initially ascended but then subsequently descended as logging intensity escalated. The stand-state zenith was pinpointed at an approximate 30% logging intensity. (3) A highly significant linear correlation emerged between the unit circle method results and the principal component analysis results in evaluating stand state (R2 = 0.909, p < 0.001), and the unit circle method proved to be more intuitive and responsive. In summation, logging intensity exerted a substantial influence on stand state in middle-aged P. massoniana plantations, with moderate logging (circa 30% logging intensity) enhancing stand state the most. The unit circle method proficiently and effectively illuminated the short-term effects of logging intensity on the stand dynamics of middle-aged P. massoniana plantations, so it thereby may provide invaluable guidance for the formulation of specific forest management strategies.

Introduction: Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus, has led to widespread logging interventions in subtropical China, especially clearcutting, yet the ecological consequences for insect communities remain poorly understood. Insects play critical roles in ecosystem functioning, making it essential to quantify how different logging strategies shape their diversity, community composition, and functional guilds.Methods: We established 48 stratified plots across four PWD-affected counties in Jiangxi Province to compare unlogged controls (UC), selection cutting (SC), and clearcutting (CC) treatments. Insect diversity was evaluated using Shannon and Simpson indices, while community structure was analyzed with PERMANOVA and NMDS ordinations. Indicator species were identified via IndVal analysis. Functional guild dynamics were measured across trophic groups, and structural equation modeling (SEM) was used to assess vegetation cover and litter thickness as mediators of diversity responses.Results: Clearcutting caused significant declines in insect diversity (Shannon index: UC 3.63 ± 0.02 vs. CC 3.14 ± 0.18; F = 19.17, p = 0.00057; Simpson index: UC 0.960 vs. CC 0.919). PERMANOVA attributed 60.7–89.5% of variation in insect community structure to logging treatment (p < 0.05), with NMDS ordinations showing distinct clustering: CC sites were dominated by disturbance-tolerant taxa (e.g., Cicindelidae, IndVal = 0.94), while UC sites harboured specialists (e.g., Libellulidae, IndVal = 0.95). Functional guild analysis revealed strong reductions in predators (−63.7%) and parasitoids (p < 0.001) under CC, whereas decomposers were relatively resilient. SEM demonstrated that vegetation cover (β = 0.69, p < 0.001) and litter thickness (β = 0.25, p = 0.041) acted as key mediators, with logging intensity indirectly depressing insect diversity via microhabitat degradation (model R2 = 0.81).Discussion and conclusion: Our findings show that intensive clearcutting exacerbates biodiversity loss and trophic collapse in insect communities of PWD-affected pine forests, largely through reductions in vegetation structure and litter. In contrast, lighter interventions such as selection cutting supported greater ecological resilience. To balance disease control with biodiversity conservation, retention forestry practices maintaining ≥30% canopy cover and 20–30 m3/ha deadwood are recommended to buffer microhabitats and sustain insect community functioning.

A typical case of multiple-use forest management (MFM) in Southwestern Amazon is the commercial harvesting of Amazon or Brazil nut (Bertholletia excelsa) seeds and of timber of other tree species. Although the Amazon nut is the most important non-timber forest product (NTFP) in the Amazon basin, the species is under serious threat due to deforestation and may also be affected by overharvesting. However, selective logging of other tree species coexisting with Bertholletia may positively affect Bertholletia populations, thus enabling a special case for MFM. For this research, we investigated the impact of the intensity of Amazon nut harvesting and timber logging on Bertholletia populations in the Bolivian Amazon. We used demographic data from 72 two-hectare transects located within 24 community-based household forests varying in the intensity of nut collection (0–100%) and timber logging (0–15% of logging-disturbed forest area). Simulated Bertholletia population size increased with logging intensity but decreased with Amazon nut harvesting intensity. Bertholletia populations were projected to grow at the average MFM harvesting scenario tested: 57.4% of nut harvesting, 5.3% of logging-disturbed area (λ100 = 1.011). Our simulations also revealed that up to 89% of Amazon nut seeds can be harvested while sustaining Bertholletia populations, under 15% of logging-disturbed area, and applying liana cutting. Modest levels of timber logging and application of liana cutting may compensate for the negative effect of Amazon nut collection on Bertholletia populations for the next century. Our study demonstrates that Amazon nut and timber production could be combined in a sustainable MFM scheme, thus increasing the economic value of managed tropical forests and its promotion to reduce the increasing pressure by deforestation.

Exotic earthworms from Europe and Asia have invaded previously earthworm-free areas of North America where they consume leaf litter, mix soil horizons, and alter nutrient cycling. Primarily, earthworm introductions occur through human activities; we hypothesized that the combination of logging (i.e., road construction and soil disturbance) and stream transport (i.e., hydrochory) allows earthworms to invade new ecosystems and spread within watersheds. On Prince of Wales Island, AK, we surveyed riparian zones in 11 watersheds with varying timber harvest intensity for terrestrial oligochaetes. Additionally, common invasive earthworms were experimentally submerged in a local stream to test for tolerance to prolonged immersion: all taxa survived immersion for at least 6 days. Using principal components analysis, watershed and harvest variables describing the watersheds upstream of our sampled riparian areas were reduced to two principal components describing harvest intensity (PC1) and harvest style (PC2). Logistic models successfully predicted earthworm abundance (r ² = 0.70) from PC1, which indicated that watersheds with older, intense upstream timber harvest contained larger earthworm populations. Earthworm species richness was best predicted by PC2 (r ² = 0.39), which suggested that earthworm communities in watersheds containing large clear-cut stands were more species-rich. Collectively, these results suggest that (1) invasive earthworms may use streams for dispersal and (2) upstream introductions via timber harvest can initiate downstream earthworm invasions. Hydrochory would allow invasive earthworms to spread at rates (tens of km d⁻¹) that are much greater than previously reported rates of terrestrial spread (5-10 m y⁻¹). Effective control of exotic earthworms in riparian zones will require watershed-level management and surveillance.

Forest harvesting alters plant litter inputs to soil and modifies the soil environment, which could alter the composition and function of soil microbial communities. Harvest-induced reductions in microbial activity could eventually feed back to modify soil N availability and forest productivity. We reasoned that increasing harvest intensity should decrease microbial community biomass and function via reduced litter input to soil. We further expected microbial communities to differ in response to harvest intensity in aspen-dominated (Populus tremuloides Michx. and P. grandidentata Michx.) forests located in climatically and edaphically different conditions. To test these ideas, we quantified microbial community composition and function 8 to 10 yr following harvest in two climatically and edaphically distinct aspen-dominated forests in Michigan. Harvest treatments included control (no harvest), merchantable bole harvest (MBH), total tree harvest (TTH), and total tree harvest + forest floor removal (FFR). Microbial community composition was quantified using phospholipid fatty acid (PLFA) analysis, and microbial community function was assayed using extracellular enzyme activity and 15N pool dilution. All harvest methods reduced microbial biomass (-24%), the activity of extracellular enzymes involved with litter decomposition (-10 to -30%), gross N mineralization (-36%), and microbial N immobilization (-38%), regardless of climatic and edaphic differences between stand locations. Microbial community composition was not affected by harvest treatment, nor did it differ between locations. Lower rates of extracellular enzyme activity and gross N transformation in harvested aspen stands corresponded with a reduction in microbial biomass, which in turn may be driven by reduced litter input and changes in soil microclimate following clear-cut harvest.