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This study aimed to assess the financial viability of forest concessions in the state of Pará, Brazil. Two Forest Management Units (FMUs) were analyzed: FMU-2, located in Saracá-Taquera National Forest, and FMU-3, located in Caxiuanã National Forest. Financial indicators were evaluated under different timber productivity scenarios (20 m3/ha and 25.8 m3/ha). At a logging intensity of 20 m3/ha, FMU-2 was not financially viable. However, both FMUs were financially viable at 25.8 m3/ha. Sensitivity analysis demonstrated that FMU-2 requires a logging intensity of over 22 m3/ha and a sawmill yield efficiency of at least 45%. The ideal cost for sawn wood would be USD 226.53/m3, with royalties of USD 16.00/m3. FMU-3 consistently demonstrated positive financial results, despite fluctuations in production costs. The financial viability of investing in forest concessions in state of Pará depends largely on forest productivity, sawmill yield, royalties, and sawn wood costs. [ABSTRACT FROM AUTHOR]

The scarcity of hardwoods from tropical forests makes the search for alternative species necessary for commercialization. This study aimed to establish groups of timber species from the Amazon Forest with potential for logging purposes through the assessment of their physical-mechanical properties, aiming to identify alternative species that can meet the market demands. We utilized data from the Forest Products Laboratory (LPF) (containing information on basic density and other wood mechanical properties) and the Timberflow platform, as well. We applied a multivariate cluster analysis technique with the aim of grouping species based on the technological characteristics of their wood and evaluating similarity among them to obtain homogeneous groups in terms of economic potential and utilization. The results indicated four homogeneous groups: Cluster 1 (40.72% of species, basic density-db: 690 kg m−3), Cluster 2 (13.92%, db: 260 and 520 kg m−3), Cluster 3 (27.32%, db: 550 and 830 kg m−3), and Cluster 4 (18.04%, db: 830 kg m−3). Most of the 20 listed species are classified as more commercially viable (70%), with high wood density. Species identified as alternatives include Dialium guianense and Zollernia paraensis for Dipteryx odorata, Terminalia argentea for Dinizia excelsa, Terminalia amazonia and Buchenavia grandis for Goupia glabra, and Protium altissimum and Maclura tinctoria for Hymenaea courbaril. The analysis highlighted the overexploitation of a restricted group of species and the need to find alternatives to ensure the sustainability of forest management. This study contributed to identifying species that can serve as alternatives to commercial ones, promoting a more balanced and sustainable forest management. [ABSTRACT FROM AUTHOR]

A brief analysis of studies on logging equipment has allowed us to conclude that it is necessary to further study the degree of influence of silvicultural and taxation indicators of the stand, containing quantitative data on the trees harvested and remaining for rearing, on the productivity of the harverster. The degree of influence of quantitative indicators of the stand on the work of the harvester is random, which is due to the infinitely wide variety of options for the spatial arrangement of trees in forest swathes. The article presents the results of a production experiment to assess the impact of the quantitative characteristics of the forest stand on the duration of individual elements of the cycle time of the harvester. The analyzed factors included the total number of trees per 1 hectare and the proportion of the felled component of the stand. These factors play a significant role in assessing the shift and hourly productivity of machines, however, when analyzing the duration of a number of elements of cycle time of manipulator machines, the importance of these indicators is underestimated by many researchers and, in order to increase the convenience and simplicity of calculations, these indicators are not used in justifying labour costs. Both factors have been considered at three levels of variation. As a result, the significant influence of the analyzed factors on the duration of 3 independent elements of cycle time of the machine (pointing the manipulator at the tree, hauling the trunk to the processing zone and moving the harvester between operating positions) has been proven. The experiment has been carried out using the Silvatec 8266TH harvester under conditions of its operation in the swathes characterized by various silvicultural and taxation indicators. The sequence of conducting the production experiment and statistical processing of the obtained data has been shown. The analysis of variance has allowed us to conclude that it is necessary to comprehensively take into account the analyzed factors when assessing each technological operation. The results can be used to improve mathematical relationships in calculating productivity and labour costs when designing logging operations.

Forest management changes the physical environments and nutrient dynamics and then regulates the forest productivity. Soil phosphorus (P) availability is critical for productivity in tropical and subtropical forests. However, it was still poorly understood howsoil P content and fraction respond to various forest management practices in these regions. Here, we measured the soil total P, available P, and Hedley's P fractions, including inorganic and organic P (Pi and Po), in subtropical pine plantations treated with understory removal (UR), non-dominant species thinning (NDST) and dominant species thinning (DST) after nine years. Compared to plantations without management (CK), treatments such as UR, NDST, and DST decreased soil total P at 0--10 cm and soil available P at 0-- 10 cm and 10--20 cm. Increases in resin-Pi, NaOH-Pi, and C.HCl-Pi resulted in a higher total Pi in 0--10 cm (p < 0.05) in treated plots (UR, NDST, and DST) than in CK plots. UR, NDST, and DST treatments increased NaHCO3-Po and NaOH-Po (p < 0.05) but decreased C.HCl-Po at a depth of 0--10 cm. Regardless of management treatments, soil total P, available P, and P fractions in 0--10 cm showed higher contents than those in 10--20 cm. There were positive relationships between total P and total Po (p < 0.01) and between available P and total Pi. There were also positive relationships between total P, available P, NaHCO3-Pi, and NaOH-Pi (p < 0.05). In conclusion, forest management such as UR, NDST, and DST decreased soil total P and available P, and transforming soil P fractions to available P will meet the P demand following management in the pine plantations of subtropical China. [ABSTRACT FROM AUTHOR]

Selective logging can impact tree composition and the long-term sustainability of forests. Studying the ecological consequences of logging practices is crucial for guiding forest management strategies aiming at maintaining ecological integrity and supporting landscape-level conservation goals. We investigated the consequences of very low-intensity selective logging in multiple tree life stages across a logged forest chronosequence in Gabon. We found that species composition differed between logged and unlogged forests at all life stages (seedlings, saplings, and adults), which were most pronounced in the understory of older forests (logged 10 years prior) compared to unlogged areas. However, logging explained a small portion of the variation in species composition (

BackgroundTropical forests are critical for the global carbon budget, yet they have been threatened by deforestation and forest degradation by fire, selective logging, and fragmentation. Existing uncertainties on land cover classification and in biomass estimates hinder accurate attribution of carbon emissions to specific forest classes. In this study, we used textural metrics derived from PlanetScope images to implement a probabilistic classification framework to identify intact, logged and burned forests in three Amazonian sites. We also estimated biomass for these forest classes using airborne lidar and compared biomass uncertainties using the lidar-derived estimates only to biomass uncertainties considering the forest degradation classification as well.ResultsOur classification approach reached overall accuracy of 0.86, with accuracy at individual sites varying from 0.69 to 0.93. Logged forests showed variable biomass changes, while burned forests showed an average carbon loss of 35%. We found that including uncertainty in forest degradation classification significantly increased uncertainty and decreased estimates of mean carbon density in two of the three test sites.ConclusionsOur findings indicate that the attribution of biomass changes to forest degradation classes needs to account for the uncertainty in forest degradation classification. By combining very high-resolution images with lidar data, we could attribute carbon stock changes to specific pathways of forest degradation. This approach also allows quantifying uncertainties of carbon emissions associated with forest degradation through logging and fire. Both the attribution and uncertainty quantification provide critical information for national greenhouse gas inventories.

Tropical forest degradation (e.g., anthropogenic disturbances such as selective logging and fires) alters forest structure and function and influences the forest's carbon sink. In this study, we explored structure-function relationships across a variety of degradation levels in the southern Brazilian Amazon by 1) investigating how forest structural properties vary as a function of degradation history using airborne lidar data; 2) assessing the effects of degradation on solar-induced chlorophyll fluorescence (SIF) seasonality using TROPOMI data; and 3) quantifying the contribution of structural variables to SIF using multiple regression models with stepwise selection of lidar metrics. Forest degradation history was obtained through Landsat time-series classification. We found that fire, logging, and time since disturbance were major determinants of forest structure, and that forests affected by fires experienced larger variability in leaf area index (LAI), canopy height and vertical structure relative to logged and intact forests. Moreover, only recently burned forests showed significantly depressed SIF during the dry season compared to intact forests. Canopy height and the vertical distribution of foliage were the best predictors of SIF. Unexpectedly, we found that wet-season SIF was higher in active regenerating forests (~ 4 years after fires or logging) compared with intact forests, despite lower LAI. Our findings help to elucidate the mechanisms of carbon accumulation in anthropogenically disturbed tropical forests and indicate that they can capture large amounts of carbon while recovering.

This editorial discusses the human impacts on bats in tropical ecosystems and explores sustainable actions and alternatives to mitigate these effects. The extensive conversion of natural ecosystems, particularly in tropical developing countries, poses a significant threat to bat populations. The loss of habitat and environmental degradation resulting from land use changes have led to the decline in bat species diversity and the disruption of ecosystem services provided by bats. The editorial highlights the critical role of forest cover in bat conservation, the interactions between bats and other organisms, and the impacts of environmental transformation on ecosystem service provision by bats. It emphasizes the importance of preserving intact forests, restoring secondary forests, and implementing initiatives with local populations and producers to protect bat biodiversity and promote sustainable alternatives. [Extracted from the article]

Selective logging in the tropics results in carbon emissions but also creates favourable environmental conditions for the regeneration of tree species and carbon recovery. We evaluate tree regeneration and recovery of biomass in selectively logged forests impacted by timber harvesting on the Yucatán Peninsula, Mexico. Fieldwork was conducted in two annual cutting areas logged in 2001 and 2009. Plots were established in felling, skidding and log landing sites. Regeneration of functional tree groups characterized by their growth, light demand, timber use, and recovery rates of biomass and carbon were assessed. Regeneration of 68 tree species in 54 genera and 27 families were found. Of these, 50% corresponded to marketable timber species. There was a greater presence of light-demanding seedlings and species in both annual cutting areas. Carbon recovery five and thirteen years after logging was 50.6 Mg ha−1 and 62.7 Mg ha−1, respectively, reflecting an annual gain of 1.51 Mg ha−1. Felling sites presented the highest diversity and carbon recovery and contained the highest quantity of trees >5 cm DBH and proportion of shade-tolerant species, providing a variety of future crop trees. Low logging intensity and practices that reduce impacts can result in the successful recovery of timber species and forest carbon. Community managed forests recover carbon rapidly after low intensity selective logging and serve as carbon reserves. Low intensity selective logging with reduced impact logging practices minimizes harvest disturbance and allows for natural regeneration of timber species. Carbon recovery and capture after selective logging under low intensities provides economic and social opportunities through carbon offset projects. [ABSTRACT FROM AUTHOR]

Silvicultural practices affect over 30 % of the global forest area and are a major driver of forest degradation. Logging is a forest management practice that is becoming increasingly widespread, since it is an important source of income for developing countries. Despite the expanding body of research on aboveground communities, little is known about the effects of logging on belowground communities. We conducted a qualitative systematic literature review to assess the current state of knowledge about the impact of logging on soil biodiversity and ecosystem functions. We addressed the effects of logging operations (e.g., clear-cutting, selective logging) on i) soil organisms (from microorganisms to soil fauna) and ii) soil functions mediated by soil biota. In general, the reviewed articles reported a negative effect of logging operations on abundance and diversity of microorganisms. Regarding soil fauna, most studies focus on insect taxa, with the impact on other soil fauna taxa remaining poorly understood. Decomposition was the most commonly studied ecosystem function. In general, the literature has reported negative effects of logging on soil functions; however, some studies found neutral or positive responses. This review highlights that logging operations have detrimental effects on a variety of different groups of organisms (e.g., microorganisms and insects) and functions (e.g., decomposition, microbial activity, bioturbation). However, on the basis of the evidence to date, low-intensity logging operations can be a beneficial practice for the conservation of soil organisms and ecosystem functions.

Selective logging in the tropics results in carbon emissions but also creates favourable environmental conditions for the regeneration of tree species and carbon recovery. We evaluate tree regeneration and recovery of biomass in selectively logged forests impacted by timber harvesting on the Yucatán Peninsula, Mexico. Fieldwork was conducted in two annual cutting areas logged in 2001 and 2009. Plots were established in felling, skidding and log landing sites. Regeneration of functional tree groups characterized by their growth, light demand, timber use, and recovery rates of biomass and carbon were assessed. Regeneration of 68 tree species in 54 genera and 27 families were found. Of these, 50% corresponded to marketable timber species. There was a greater presence of light-demanding seedlings and species in both annual cutting areas. Carbon recovery five and thirteen years after logging was 50.6 Mg ha−1 and 62.7 Mg ha−1, respectively, reflecting an annual gain of 1.51 Mg ha−1. Felling sites presented the highest diversity and carbon recovery and contained the highest quantity of trees >5 cm DBH and proportion of shade-tolerant species, providing a variety of future crop trees. Low logging intensity and practices that reduce impacts can result in the successful recovery of timber species and forest carbon.

Accurate mapping of selective logging (SL) serves as the foundation for additional research on forest restoration and regeneration, species diversification and distribution, and ecosystem dynamics, among other applications. This study aimed to model canopy gaps created by illegal logging of Ocotea usambarensis in Mt. Kenya Forest Reserve (MKFR). A texture-spectral analysis approach was applied to exploit the potential of WorldView-3 (WV-3) multispectral imagery. First, texture properties were explored in the sub-band images using fused grey-level co-occurrence matrix (GLCM)- and local binary pattern (LBP)-based texture feature extraction. Second, the texture features were fused with colour using the multivariate local binary pattern (MLBP) model. The G-statistic and Euclidean distance similarity measures were applied to increase accuracy. The random forest (RF) and support vector machine (SVM) were used to identify and classify distinctive features in the texture and spectral domains of the WV-3 dataset. The variable importance measurement in RF ranked the relative influence of sets of variables in the classification models. Overall accuracy (OA) scores for the respective MLBP models were in the range of 80–95.1%. The respective user’s accuracy (UA) and producer’s accuracy (PA) for the univariate LBP and MLBP models were in the range of 67–75% and 77–100%, respectively.

Tropical montane forests are critical centres of terrestrial biodiversity and endemism, and face a range of threats, including selective logging and climate change. However, few studies have explored the joint influence of these threats, particularly in tropical mountains, despite how crucial it is to understand the cumulative impact of forest loss and climate change on biodiversity. We used mist-netting and bird ringing data from a long-term (10-year) community and population monitoring program to examine how the composition of the mid-elevation Eastern Himalayan understorey bird community changed in the mid-elevation primary and logged forest. Because logged forest is warmer than primary forest, we hypothesised that the bird community would shift towards lower elevation species, with a faster transition in logged forest. Further, because logged forest has lower arthropod abundance, we hypothesised that the primary forest community would have larger species than the logged forest community. Our study shows that the bird community in the logged forest shifted towards lower-elevation species than in the primary forest (although this was not statistically significant). Moreover, we found that smaller species were better able to colonise warmer logged forest, whereas larger species reached higher densities in primary forest. These trends are likely to be driven by climate change causing upslope range shifts and logged forest selecting for species that are likely to tolerate the consequently altered abiotic (higher temperatures) and biotic (lower resources) environment. These findings have significant implications for understanding the impacts of forest loss and climate change on biodiversity, particularly in tropical montane forests.

This article analysed the 25–30 years of growth of dipterocarps forests that were logged under the Selective Management System (SMS) at three sites in Peninsular Malaysia to understand how management regimes affected forest stem density and basal area. The management regimes were (1) unlogged, (2) moderately logged forests that logged all dipterocarps ≥ 65 cm diameter at breast height (dbh) and all non-dipterocarps ≥ 60 cm dbh, and (3) intensely logged forests that logged all dipterocarps ≥ 50 cm dbh and nondipterocarps ≥ 45 cm dbh. The intensely logged regime is similar to the SMS practices in Peninsular Malaysia. This result showed that one-year post-logging, there was no difference in the total stem density and basal area between forests logged according to the two management regimes. Forest stem density decreased over time in all management regimes, significantly greater in unlogged forests (-15.1 stems/ha/yr, confidence interval (CI): -16.9 to -13.3). This decline in stem density reflected that mortality exceeded recruitment in all management regimes. Despite the consistent decline of forest stem density, the basal area increased over time, and the rate of increase in the intensely logged forest (0.22 m² /ha/yr, CI: 0.19 to 0.25)was significantly greater than the other management regimes. Our study showed that 30 years post-logging, the effect of selective logging remained evident. Both logged forest stem density and the basal area did not recover to that of unlogged forests, indicating the importance of enrichment planting and extending the cutting cycles beyond 30 years for the sustainability of dipterocarps forests. [ABSTRACT FROM AUTHOR]

This study was carried out in the territories of Northern Europe, in the middle taiga subzone of Karelia. The paper presents the results of a study of an experiment on logging to study the impact of controlled logging using supervised logging with controlling cutting (SLCC) and conventional logging (CL) on the properties of soils (horizons O, E and BF) in a spruce forest 15 years after logging. Virgin forest (VF) was used as a control. The volume weight of soils, the contents of carbon, nitrogen and potassium in different soil layers (layers O, E and BF), as well as reserves of C, N and K and their stratification coefficients SRs (SR1 [O:E], SR2 [O:BF] and SR3 [E:BF]) were studied. The results showed a tendency to increase the volume weight of soils of anthropogenically disturbed (CL and SLCC) areas can be measured. The obtained data demonstrated that there was no sharp change in the contents or stocks of the studied elements between the anthropogenically disturbed (CL and SLCC) and undisturbed areas (VF). The largest reserves of carbon, nitrogen and potassium were noted in the upper horizons of the soils of all sites, averaging 35.6, 1.27 and 0.073 t/ha, respectively. In the lower horizons of the studied soils, the values were lower. The values of the stratification coefficients in the studied soils were arranged in decreasing order as SR2 > SR1 > SR3. At the same time, the general trend of unidirectional changes in the SR values for carbon and potassium in soils was noted; the data for nitrogen were somewhat different. The results showed a marked decrease in SOC concentration with an increase in soil depth. Higher rates of cellulose decomposition were observed in anthropogenically disturbed areas (CL—69.0 ± 3.6%; SLCC—57.4 ± 3.5%) compared with virgin forest (VF) (53.7 ± 3.1%), which is consistent with the results of other studies in the taiga zone. The data obtained indicate the importance of a more accurate assessment of the contents and stocks of elements, as well as the need to use tests for soil biological activity. [ABSTRACT FROM AUTHOR]

Abstract Background Tropical forests are critical for the global carbon budget, yet they have been threatened by deforestation and forest degradation by fire, selective logging, and fragmentation. Existing uncertainties on land cover classification and in biomass estimates hinder accurate attribution of carbon emissions to specific forest classes. In this study, we used textural metrics derived from PlanetScope images to implement a probabilistic classification framework to identify intact, logged and burned forests in three Amazonian sites. We also estimated biomass for these forest classes using airborne lidar and compared biomass uncertainties using the lidar-derived estimates only to biomass uncertainties considering the forest degradation classification as well. Results Our classification approach reached overall accuracy of 0.86, with accuracy at individual sites varying from 0.69 to 0.93. Logged forests showed variable biomass changes, while burned forests showed an average carbon loss of 35%. We found that including uncertainty in forest degradation classification significantly increased uncertainty and decreased estimates of mean carbon density in two of the three test sites. Conclusions Our findings indicate that the attribution of biomass changes to forest degradation classes needs to account for the uncertainty in forest degradation classification. By combining very high-resolution images with lidar data, we could attribute carbon stock changes to specific pathways of forest degradation. This approach also allows quantifying uncertainties of carbon emissions associated with forest degradation through logging and fire. Both the attribution and uncertainty quantification provide critical information for national greenhouse gas inventories.

This study aimed to investigate how sustainable forest management can affect litter hydrological properties. We investigated the net precipitation, litter mass, water-holding capacity, effective water-holding and retention capacity, maximum water retention and water content in unlogged and logged forests over 13 months in the Amazon Forest, where reduced-impact logging is allowed. The mean litter mass was similar for unlogged and logged forests. The litter water-holding capacity was 220% for unlogged and 224% for logged forests, and for fractions followed: unstructured > leaves > seeds > branches for both forests. The effective water-holding capacity was 48.7% and 49.3% for unlogged and logged, respectively, and the effective water retention was 10.3 t·ha−1 for both forests. The effective water retention in the rainy and dry seasons accounted for 12.5 t ha−1 and 7.2 t ha−1 for unlogged and logged, respectively. The maximum water retention was slightly greater for logged forests (16.7 t ha−1) than unlogged (16.3 t ha−1). The litter water content had 40% less water in the dry season than in the rainy in both forests. In general, there were no significant differences in litter storage and hydrological properties between stands. This suggests that reduced-impact logging did not significantly affect the hydrological dynamics of the litter layer in the Amazonian forests studied. [ABSTRACT FROM AUTHOR]

Accurate mapping of selective logging (SL) serves as the foundation for additional research on forest restoration and regeneration, species diversification and distribution, and ecosystem dynamics, among other applications. This study aimed to model canopy gaps created by illegal logging of Ocotea usambarensis in Mt. Kenya Forest Reserve (MKFR). A texture-spectral analysis approach was applied to exploit the potential of WorldView-3 (WV-3) multispectral imagery. First, texture properties were explored in the sub-band images using fused grey-level co-occurrence matrix (GLCM)- and local binary pattern (LBP)-based texture feature extraction. Second, the texture features were fused with colour using the multivariate local binary pattern (MLBP) model. The G-statistic and Euclidean distance similarity measures were applied to increase accuracy. The random forest (RF) and support vector machine (SVM) were used to identify and classify distinctive features in the texture and spectral domains of the WV-3 dataset. The variable importance measurement in RF ranked the relative influence of sets of variables in the classification models. Overall accuracy (OA) scores for the respective MLBP models were in the range of 80–95.1%. The respective user's accuracy (UA) and producer's accuracy (PA) for the univariate LBP and MLBP models were in the range of 67–75% and 77–100%, respectively. [ABSTRACT FROM AUTHOR]

Background: Selective logging is a frequent practice in the Tropical Montane Cloud Forest which can impact forest regeneration and the genetic makeup of successive generations of trees. The spatial clustering of genetically related individuals, fine-scale genetic structure (FSGS), can develop from the reduction of gene dispersal and the decrease in the number of reproductive individuals at the local scale due to selective logging. Questions: In regeneration sites with a history of selective logging, does FSGS differ from a site without such a history? Is FSGS stronger in seedlings and saplings relative to juveniles and adults? Is genetic diversity similar among life stages and sites? Studied species: Magnolia iltisiana an endemic tree. Study site and dates: Sierra de Manantlan Biosphere Reserve, Jalisco, Mexico. 2020. Methods: We evaluated genetic diversity, genetic structure, and FSGS across four life stages (seedlings, saplings, juveniles, and adults) by genotyping 211 individuals with seven nuclear microsatellite loci in two regeneration and one conserved site. Results: We found statistically significant FSGS in the two regeneration sites only for seedlings and saplings, while no evidence of FSGS was detected in the conserved site. No differences in genetic diversity estimates and structure were found among life stages. Conclusions: Our study does not suggest an effect of selective logging on genetic diversity on the contrasted conditions and an FSGS pattern only in the earlier stages of the regeneration sites in M. iltisiana.

Forest degradation is common in tropical landscapes, but estimates of the extent and duration of degradation impacts are highly uncertain. In particular, selective logging is a form of forest degradation that alters canopy structure and function, with persistent ecological impacts following forest harvest. In this study, we employed airborne laser scanning in 2012 and 2014 to estimate three-dimensional changes in the forest canopy and understory structure and aboveground biomass following reduced-impact selective logging in a site in Eastern Amazon. Also, we developed a binary classification model to distinguish intact versus logged forests. We found that canopy gap frequency was significantly higher in logged versus intact forests even after 8 years (the time span of our study). In contrast, the understory of logged areas could not be distinguished from the understory of intact forests after 6–7 years of logging activities. Measuring new gap formation between LiDAR acquisitions in 2012 and 2014, we showed rates 2 to 7 times higher in logged areas compared to intact forests. New gaps were spatially clumped with 76 to 89% of new gaps within 5 m of prior logging damage. The biomass dynamics in areas logged between the two LiDAR acquisitions was clearly detected with an average estimated loss of −4.14 ± 0.76 MgC ha−1 y−1. In areas recovering from logging prior to the first acquisition, we estimated biomass gains close to zero. Together, our findings unravel the magnitude and duration of delayed impacts of selective logging in forest structural attributes, confirm the high potential of airborne LiDAR multitemporal data to characterize forest degradation in the tropics, and present a novel approach to forest classification using LiDAR data.

The Sunda Clouded Leopard Neofelis diardi on Borneo is threatened principally by deforestation for oil palm plantations and the indiscriminate use of illegal trapping. Sunda Clouded Leopard populations are decreasing across their range, and the species has been categorised as Vulnerable on the IUCN Red List. Despite the persistence of threats and numerous surveys in recent years, information on its ecology is still limited. Most studies to date have relied on the use of camera traps as their primary sampling tool, as it is challenging otherwise to gather data on Sunda Clouded Leopards. This study aimed to test the feasibility of estimating the Sunda Clouded Leopard occupancy using a different approach. We conducted vehicle spotlight transect surveys in a mixed-use forest reserve and logging concession in Sabah. We drove a cumulative total of 8,433 km of transects at night and documented the occurrence of Sunda Clouded Leopards in eight out of 31 predetermined long-distance transects, yielding a relatively low na􀅢ve occupancy rate (nO 􀑁 0.26). When accounting for imperfect detection (􀊌 􀑁 0.15), null occupancy of Sunda Clouded Leopards appeared much higher (􀢱 􀑁 0.55), though our parameter estimates lacked relative precision. Despite this, our results suggest there may be potential to further refine and adapt a basic, cost-effective monitoring approach in a local mixed-use reserve with the help of concession managers and additional improvements to study design. We caution, however, that not all study sites may be suited for this type of approach and strongly advise the development of pilot studies to evaluate their overall feasibility. [ABSTRACT FROM AUTHOR]

This study investigates the integration of assisted natural regeneration (ANR) and selective logging (SL) to guarantee a sustainable forest operation in the Philippines using agent-based modeling. To assess the sustainability of the operation in light of the revenue from timber harvesting and the health of the forest in terms of the total number of trees, various simulations were run on a theoretical forest modeled after the Mount Makiling Forest Reserve in the Philippines. The findings of the simulation have shown that, even after many years of continuous use, the performance of SL on a healthy forest similar to the theoretical forest is substantially identical with and without ANR. The "with ANR" setup, however, was able to demonstrate a considerably better and more stable harvest value over the final 100 years than the "without ANR" setup. In terms of ensuring sustainable forest cover, simulation findings showed that even after 500 years of continuous SL activity, the forest cover could be maintained to up to 80% with ANR. The model has shown that with the right combination of reforestation efforts and timber harvesting methods, a sustainable forest operation can contribute to the country's economic needs for timber production while ensuring that the forest is actively managed. [ABSTRACT FROM AUTHOR]

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This study assesses ALOS-2/PALSAR-2 (ALOS2) polarimetric images for detecting forest volume losses due to selective logging in a region in the Brazilian Amazon. Two logging-intensive areas, APU 2016, and APU 2017, were studied. ALOS2 imagery attributes, including backscatter and phase data, were analyzed for differences between logged and unlogged regions using Wilcoxon’s nonparametric test at a 95% confidence level. The Radar Normalized Difference Vegetation Index proved effective in detecting selective logging-induced forest volume losses, with consistent results (p-values of 0.003 for APU 2016 and 0.037 for APU 2017). These findings provide insights for monitoring and mitigating ecological impacts of logging in complex forest ecosystems.

Forest fragmentation is a major driver of tropical bird endangerment, yet the mechanisms underlying species losses in fragmented landscapes remain poorly known. Loss of foraging microhabitats and food diversity in fragmented landscapes are potential mechanisms explaining fragmentation sensitivity. We, therefore, measured the body condition (i.e., body mass adjusted for individual size) of 20 tropical understory birds as a proxy for food availability across gradients of fragment patch size and silvicultural histories in the Western Andes of Colombia. Specifically, we asked (1) if body condition correlates with patch size, edge effects, or selective logging disturbance; and (2) if species responses were driven by the same explanatory variables or varied idiosyncratically. We documented significant variation in body condition with covariates in 11 of 20 (55%) understory bird species, and 55% of significant correlations were with fragmentation and selective-logging associated variables. Species responses were idiosyncratic and contrasting, with at least 1 significant response to each fragmentation-related covariate. Most effects, however, were driven by logging-induced changes to vegetation structure including loss of large-diameter trees, reduction in foliage height diversity and canopy cover, and loss of understory vegetation. The body condition of frugivores and nectarivores increased with logging-induced shifts in vegetation structure, with canopy gaps potentially favoring early-successional fruiting and flowering plants. By contrast, some insectivores suffered lower body condition with loss of vegetation structure (reduced foliage height diversity). Overall, our data support the hypothesis that fragmentation and selective logging change food resources available to birds and that some widespread nectarivores, frugivores, and omnivores may benefit from increasing edge density and logging-driven vegetation disturbance. We also documented significant positive effects of breeding condition on body condition, however, highlighting the need to control for this factor. Body condition may therefore be a useful index of habitat suitability when paired with analyses of abundance and demographic changes. [ABSTRACT FROM AUTHOR]

Forest logging detection is important for sustainable forest management. The traditional optical satellite images with visible and near-infrared bands showed the ability to identify intensive timber logging. However, less intensive logging is still difficult to detect with coarse spatial resolution such as Landsat or high spatial resolution in fewer spectral bands. Although more high-resolution remote sensing images containing richer spectral bands can be easily obtained nowadays, the questions of whether they facilitate the detection of logging patterns and which spectral bands are more effective in detecting logging patterns, especially in selective logging, remain unresolved. Therefore, this paper aims to evaluate the combinations of visible, near-infrared, red-edge, and short-wave infrared bands in detecting three different logging intensity patterns, including unlogged (control check, CK), selective logging (SL), and clear-cutting (CC), in north subtropical plantation forests with the random forest algorithm using Sentinel-2 multispectral imagery. This study aims to explore the recognition performance of different combinations of spectral bands (visual (VIS) and near-infrared bands (NIR), VIS, NIR combined with red-edge, VIS, NIR combined with short-wave infrared bands (SWIR), and full-spectrum bands combined with VIS, NIR, red edge and SWIR) and to determine the best spectral variables to be used for identifying logging patterns, especially in SL. The study was conducted in Taizishan in Hubei province, China. A total of 213 subcompartments of different logging patterns were collected and the random forest algorithm was used to classify logging patterns. The results showed that full-spectrum bands which contain the red-edge and short-wave infrared bands improve the ability of conventional optical satellites to monitor forest logging patterns and can achieve an overall accuracy of 85%, especially for SL which can achieve 79% and 64% for precision and recall accuracy, respectively. The red-edge band (698–713 nm, B5 in Sentinel-2), short-wave infrared band (2100–2280 nm, B12 in Sentinel-2), and associated vegetation indices (NBR, NDre2, and NDre1) enhance the sensitivity of the spectral information to logging patterns, especially for the SL pattern, and the precision and recall accuracy can improve by 10% and 6%, respectively. Meanwhile, both clear-cutting and unlogged patterns could be well-classified whether adding a red-edge or SWIR band or both in VIS and NIR bands; the best precision and recall accuracies for clear-cutting were enhanced to 97%, 95% and 81%, 91% for unlogged, respectively. Our results demonstrate that the optical images have the potential ability to detect logging patterns especially for the clear-cutting and unlogged patterns, and the selective logging detection accuracy can be improved by adding red-edge and short-wave infrared spectral bands. [ABSTRACT FROM AUTHOR]

Animal density is a fundamental parameter in ecology and conservation, and yet it has remained difficult to measure. For terrestrial mammals and birds, camera‐traps have dramatically improved our ability to collect systematic data across a large number of species, but density estimation (except for species with natural marks) is still faced with statistical and logistical hurdles, including the requirement for auxiliary data and large sample sizes, and an inability to incorporate covariates.To fill this gap in the camera‐trapper's statistical toolbox, we extended the existing Random Encounter Model (REM) to the multi‐species case in a Bayesian framework. This multi‐species REM can incorporate covariates and provides parameter estimates for even the rarest species. As input to the model, we used information directly available in the camera‐trap data. The model outputs posterior distributions for the REM parameters—movement speed, activity level, the effective angle and radius of the camera‐trap detection zone, and density—for each species. We applied this model to an existing dataset for 35 species in Borneo, collected across old‐growth and logged forest. Here, we added animal position data derived from the image sequences in order to estimate the speed and detection zone parameters.The model revealed a decrease in movement speeds, and therefore day‐range, across the species community in logged compared to old‐growth forest, whilst activity levels showed no consistent trend. Detection zones were shorter, but of similar width, in logged compared to old‐growth forest. Overall, animal density was lower in logged forest, even though most species individually occurred at higher density in logged forest. However, the biomass per unit area was substantially higher in logged compared to old‐growth forest, particularly among herbivores and omnivores, likely because of increased resource availability at ground level. We also included body mass as a variable in the model, revealing that larger‐bodied species were more active, had more variable speeds, and had larger detection zones.Caution is warranted when estimating density for semi‐arboreal and fossorial species using camera‐traps, and more extensive testing of assumptions is recommended. Nonetheless, we anticipate that multi‐species density estimation could have very broad application. [ABSTRACT FROM AUTHOR]

Selective logging is a major cause of forest degradation in the tropics, but its precise scale, location and timing are not known as wide-area, automated remote sensing methods are not yet available at this scale. This limits the abilities of governments to police illegal logging, or monitor (and thus receive payments for) reductions in degradation. Sentinel-1, a C-band Synthetic Aperture Radar satellite mission with a 12-day repeat time across the tropics, is a promising tool for this due to the known appearance of shadows in images where canopy trees are removed. However, previous work has relied on optical satellite data for calibration and validation, which has inherent uncertainties, leaving unanswered questions about the minimum magnitude and area of canopy loss this method can detect. Here, we use a novel bi-temporal LiDAR dataset in a forest degradation experiment in Gabon to show that canopy gaps as small as 0.02 ha (two 10 m × 10 m pixels) can be detected by Sentinel-1. The accuracy of our algorithm was highest when using a timeseries of 50 images over 20 months and no multilooking. With these parameters, canopy gaps in our study site were detected with a false alarm rate of 6.2%, a missed detection rate of 12.2%, and were assigned disturbance dates that were a good qualitative match to logging records. The presence of geolocation errors and false alarms makes this method unsuitable for confirming individual disturbances. However, we found a linear relationship ( r 2 = 0.74 ) between the area of detected Sentinel-1 shadow and LiDAR-based canopy loss at a scale of 1 hectare. By applying our method to three years' worth of imagery over Gabon, we produce the first national scale map of small-magnitude canopy cover loss. We estimate a total gross canopy cover loss of 0.31 Mha, or 1.3% of Gabon's forested area, which is a far larger area of change than shown in currently available forest loss alert systems using Landsat (0.022 Mha) and Sentinel-1 (0.019 Mha). Our results, which are made accessible through Google Earth Engine, suggest that this approach could be used to quantify the magnitude and timing of degradation more widely across tropical forests. [ABSTRACT FROM AUTHOR]

Unprotected lands can help prevent the extinctions of species if managed carefully. Over half of the tropical forest is leased by logging companies, whereas only 6%–18% is protected. This makes the timber industry, institutions that regulate it, and consumers of its products important actors in conservation. We assessed the conservation responsibility, the proportion of a species' range that tropical timber industry concessions overlap with, for bird species that decline after selective logging. Up to 32% of the global range and up to 100% of the national range of sensitive species within our study countries are leased by logging companies. Individual concessions overlap with the ranges of up to 25 sensitive and more than 500 total bird species, with a particularly high density in Borneo. Our results can inform governments, forest managers, sustainability certifiers, and consumers so that they can turn this responsibility into a conservation opportunity through interventions at multiple scales. [ABSTRACT FROM AUTHOR]

Abstract Unprotected lands can help prevent the extinctions of species if managed carefully. Over half of the tropical forest is leased by logging companies, whereas only 6%–18% is protected. This makes the timber industry, institutions that regulate it, and consumers of its products important actors in conservation. We assessed the conservation responsibility, the proportion of a species’ range that tropical timber industry concessions overlap with, for bird species that decline after selective logging. Up to 32% of the global range and up to 100% of the national range of sensitive species within our study countries are leased by logging companies. Individual concessions overlap with the ranges of up to 25 sensitive and more than 500 total bird species, with a particularly high density in Borneo. Our results can inform governments, forest managers, sustainability certifiers, and consumers so that they can turn this responsibility into a conservation opportunity through interventions at multiple scales.

Fruits and seeds are key food resources for most Amazonian mammals and birds. Selective logging is an increasingly dominant land use in the region that can deplete these resources over large areas. However, this potential impact remains poorly studied. Here we assess potential losses of animal-dispersed (endozoochorous and synzoochorous) trees resulting from reduced-impact logging in Amazonian forest concessions. We use data from forestry surveys conducted by concession companies that include the location, identity and fate (logged or not) of large (≥ 40 cm diameter at breast height) individual trees within concessions to quantify absolute and relative losses of animal-dispersed trees in the landscape. We found that most individual trees (66%) within concessions belong to animal-dispersed genera. However, despite their predominance these trees were significantly less targeted for logging than abiotically-dispersed trees so that their losses were much lower than expected based on overall harvest intensities. However, at least ten percent of all large animal-dispersed trees were lost from the entire landscape, with site-level (50-ha plots) losses sometimes exceeding one third of all animal-dispersed trees. Results suggest that the relatively low level of logging for animal-dispersed trees can still deplete frugivore resources in selectively logged forests.

This study was carried out in the territories of Northern Europe, in the middle taiga subzone of Karelia. The paper presents the results of a study of an experiment on logging to study the impact of controlled logging using supervised logging with controlling cutting (SLCC) and conventional logging (CL) on the properties of soils (horizons O, E and BF) in a spruce forest 15 years after logging. Virgin forest (VF) was used as a control. The volume weight of soils, the contents of carbon, nitrogen and potassium in different soil layers (layers O, E and BF), as well as reserves of C, N and K and their stratification coefficients SRs (SR1 [O:E], SR2 [O:BF] and SR3 [E:BF]) were studied. The results showed a tendency to increase the volume weight of soils of anthropogenically disturbed (CL and SLCC) areas can be measured. The obtained data demonstrated that there was no sharp change in the contents or stocks of the studied elements between the anthropogenically disturbed (CL and SLCC) and undisturbed areas (VF). The largest reserves of carbon, nitrogen and potassium were noted in the upper horizons of the soils of all sites, averaging 35.6, 1.27 and 0.073 t/ha, respectively. In the lower horizons of the studied soils, the values were lower. The values of the stratification coefficients in the studied soils were arranged in decreasing order as SR2 > SR1 > SR3. At the same time, the general trend of unidirectional changes in the SR values for carbon and potassium in soils was noted; the data for nitrogen were somewhat different. The results showed a marked decrease in SOC concentration with an increase in soil depth. Higher rates of cellulose decomposition were observed in anthropogenically disturbed areas (CL—69.0 ± 3.6%; SLCC—57.4 ± 3.5%) compared with virgin forest (VF) (53.7 ± 3.1%), which is consistent with the results of other studies in the taiga zone. The data obtained indicate the importance of a more accurate assessment of the contents and stocks of elements, as well as the need to use tests for soil biological activity.

In tropical rainforests, gaps created by fallen canopy trees are the primary colonization sites for pioneer species. Selective logging mimics these natural disturbances in that only a single tree is felled, creating a gap of comparable size. Rates of tree felling greatly exceed natural mortality rates, however, changing disturbance regime by increasing the number of gaps in logged areas compared to intact forest. Little is known about whether gaps in logged forests are qualitatively different as well. At Gunung Palung National Park in West Kalimantan, Indonesia, a period of selective logging in areas adjacent to the research station created a natural experiment permitting comparison of populations of the invasive pioneer tree Bellucia pentamera in selectively logged and undisturbed forest. We sought to first establish whether canopy gaps are necessary for invasion by B. pentamera. We then examined whether the type of gap (logging vs. natural treefall) had an effect on recruitment. Finally, we compared populations in natural treefall gaps in logged and undisturbed forest to estimate the effect of logging on population size. Bellucia pentamera was limited to gaps, regardless of canopy tree density. Furthermore, gaps created by selective logging supported significantly more B. pentamera individuals than natural gaps. Finally, natural treefall gaps in the disturbed area contained significantly more individuals than gaps in the undisturbed forest. Therefore, it appears that selective logging not only created more gaps for B. pentamera, these gaps in particular promoted greater abundance of this invader and led to a population increase throughout the disturbed habitat.

This study aimed to investigate how sustainable forest management can affect litter hydrological properties. We investigated the net precipitation, litter mass, water-holding capacity, effective water-holding and retention capacity, maximum water retention and water content in unlogged and logged forests over 13 months in the Amazon Forest, where reduced-impact logging is allowed. The mean litter mass was similar for unlogged and logged forests. The litter water-holding capacity was 220% for unlogged and 224% for logged forests, and for fractions followed: unstructured > leaves > seeds > branches for both forests. The effective water-holding capacity was 48.7% and 49.3% for unlogged and logged, respectively, and the effective water retention was 10.3 t·ha−1 for both forests. The effective water retention in the rainy and dry seasons accounted for 12.5 t ha−1 and 7.2 t ha−1 for unlogged and logged, respectively. The maximum water retention was slightly greater for logged forests (16.7 t ha−1) than unlogged (16.3 t ha−1). The litter water content had 40% less water in the dry season than in the rainy in both forests. In general, there were no significant differences in litter storage and hydrological properties between stands. This suggests that reduced-impact logging did not significantly affect the hydrological dynamics of the litter layer in the Amazonian forests studied.

Deforestation is a major threat to terrestrial tropical ecosystems, particularly in Southeast Asia where human activities have dramatic consequences for the survival of many species. However, responses of species to anthropogenic impact are highly variable. In order to establish effective conservation strategies, it is critical to determine a species' ability to persist in degraded habitats. Here, we used camera trapping data to provide the first insights into the temporal and spatial distribution of southern pig-tailed macaques (Macaca nemestrina, listed as 'Vulnerable' by the IUCN) across intact and degraded forest habitats in Peninsular Malaysia, with a particular focus on the effects of clear-cutting and selective logging on macaque occupancy. Specifically, we found a 10% decline in macaque site occupancy in the highly degraded Pasoh Forest Reserve from 2013 to 2017. This may be strongly linked to the macaques' sensitivity to intensive disturbance through clear-cutting, which significantly increased the probability that M. nemestrina became locally extinct at a previously occupied site. However, we found no clear relationship between moderate disturbance, i.e., selective logging, and the macaques' local extinction probability or site occupancy in the Pasoh Forest Reserve and Belum-Temengor Forest Complex. Further, an identical age and sex structure of macaques in selectively logged and completely undisturbed habitat types within the Belum-Temengor Forest Complex indicated that the macaques did not show increased mortality or declining birth rates when exposed to selective logging. Overall, this suggests that low to moderately disturbed forests may still constitute valuable habitats that support viable populations of M. nemestrina, and thus need to be protected against further degradation. Our results emphasize the significance of population monitoring through camera trapping for understanding the ability of threatened species to cope with anthropogenic disturbance. This can inform species management plans and facilitate the development of effective conservation measures to protect biodiversity. [ABSTRACT FROM AUTHOR]

This paper reviews and discusses the status of remote sensing techniques applied in detecting and monitoring selective logging disturbance in tropical forests. The analyses concentrated on the period 1992-2019. Accurate and precise detection of selectively logged sites in a forest is crucial for analyzing the spatial distribution of forest disturbances and degradation. Remote sensing can be used to monitor selective logging activities and associated forest fires over tropical forests, which otherwise requires labor-intensive and time-consuming field surveys, that are costly and difficult to undertake. The number of studies on remote sensing for selective logging has grown steadily over the years, thus, the need for their review so as to guide forest management practices and current research. A variety of peer reviewed articles are discussed so as to evaluate the applicability and accuracy of different methods in different circumstances. Major challenges with existing approaches are singled out and future needs are discussed.

This study investigates the integration of assisted natural regeneration (ANR) and selective logging (SL) to guarantee a sustainable forest operation in the Philippines using agent-based modeling. To assess the sustainability of the operation in light of the revenue from timber harvesting and the health of the forest in terms of the total number of trees, various simulations were run on a theoretical forest modeled after the Mount Makiling Forest Reserve in the Philippines. The findings of the simulation have shown that, even after many years of continuous use, the performance of SL on a healthy forest similar to the theoretical forest is substantially identical with and without ANR. The “with ANR” setup, however, was able to demonstrate a considerably better and more stable harvest value over the final 100 years than the “without ANR” setup. In terms of ensuring sustainable forest cover, simulation findings showed that even after 500 years of continuous SL activity, the forest cover could be maintained to up to 80% with ANR. The model has shown that with the right combination of reforestation efforts and timber harvesting methods, a sustainable forest operation can contribute to the country’s economic needs for timber production while ensuring that the forest is actively managed.

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.

Andean forests, a hotspot of biodiversity, have suffered extensive fragmentation, yet we have little understanding of how this process has affected biodiversity. We surveyed bird communities across a gradient of fragment sizes (10–170 ha) and a continuous forest reference site in the Colombian Western Andes. Using a multi-species occupancy model to combine survey data from audio-visual transect surveys, mist netting, and playbacks for owls, we estimated alpha and beta taxonomic and functional diversity. We asked whether (1) habitat amount (patch size), edge effects, or selective logging affect bird occupancy and drive changes to diversity, (2) functional and taxonomic diversity respond similarly to fragmentation, and (3) compositional changes result from species turnover or nested species loss. Species richness declined with decreasing habitat amount, increasing edge density, and increasing disturbance through selective logging. These effects were driven by the loss of forest-dependent species, which were also area sensitive: 30 such species were absent from fragments, even the largest ones (>150 ha). Area-sensitive species were also edge sensitive and increased in occupancy in unlogged forest. We further found high beta diversity (0.78) driven by species turnover (85% of dissimilarity) along the gradient. Despite extensive turnover to non-forest species within functional groups, functional trait richness and dispersion significantly declined with habitat amount. Small fragments may mimic the structure and composition of early-successional Andean forests, driving spatial turnover patterns favoring disturbance-adapted species at the expense of primary-forest specialists. Large forest reserves are therefore required to conserve forest-dependent Andean birds.

Home range mapping studies of birds inform about area requirements and responses to land management as reflected by home range sizes and by resource selection within home ranges. Tracking studies of woodpeckers (Picidae) so far have been concentrated in temperate regions. In the subtropical Atlantic Forest of northeast Argentina, we assessed interspecific differences in home range sizes in old-growth forests and selectively logged forests of Helmeted Woodpecker (Celeus galeatus, a globally threatened species), Lineated Woodpecker (Dryocopus lineatus), and Robust Woodpecker (Campephilus robustus). Helmeted Woodpecker had larger breeding home ranges in selectively logged forests, averaging 105 ± 39 ha for pairs, versus 60 ± 13 ha in old-growth forests. Lineated Woodpecker breeding home ranges of pairs averaged 56 ± 22 ha, and those of Robust Woodpecker 43 ± 22 ha, with no differences between forest types. Helmeted Woodpeckers had an unusual separation between the home ranges of males and females in breeding pairs, with a mean area overlap of only 8% ± 9% near the nest tree, resulting in large home ranges for pairs. Helmeted Woodpecker and Robust Woodpecker individuals that were followed into the post-breeding stage had marked expansions of their home range sizes relative to breeding home ranges. To place our findings with Atlantic Forest woodpeckers in perspective we reviewed whether woodpecker home range sizes increase with latitude and body mass globally. For 29 populations of 22 woodpecker species, a power regression model with these factors explained 24.1% of variation in breeding home range sizes, with 17.1% of variation explained by latitude alone. Woodpecker species with larger home ranges than predicted values were three species of North American woodpeckers of coniferous forests, as well as the Helmeted Woodpecker. Our results of smaller home ranges in old-growth forests for the Helmeted Woodpecker affirm an association of this species with such forests. We urge the conservation of the few remaining tracts of old-growth Atlantic Forest and more restoration of logged forests to mature conditions.

Forest management changes the physical environments and nutrient dynamics and then regulates the forest productivity. Soil phosphorus (P) availability is critical for productivity in tropical and subtropical forests. However, it was still poorly understood how soil P content and fraction respond to various forest management practices in these regions. Here, we measured the soil total P, available P, and Hedley's P fractions, including inorganic and organic P (Pi and Po), in subtropical pine plantations treated with understory removal (UR), non-dominant species thinning (NDST) and dominant species thinning (DST) after nine years. Compared to plantations without management (CK), treatments such as UR, NDST, and DST decreased soil total P at 0-10 cm and soil available P at 0-10 cm and 10-20 cm. Increases in resin-Pi, NaOH-Pi, and C.HCl-Pi resulted in a higher total Pi in 0-10 cm ( p < 0.05) in treated plots (UR, NDST, and DST) than in CK plots. UR, NDST, and DST treatments increased NaHCO 3 -Po and NaOH-Po ( p < 0.05) but decreased C.HCl-Po at a depth of 0-10 cm. Regardless of management treatments, soil total P, available P, and P fractions in 0-10 cm showed higher contents than those in 10-20 cm. There were positive relationships between total P and total Po ( p < 0.01) and between available P and total Pi. There were also positive relationships between total P, available P, NaHCO 3 -Pi, and NaOH-Pi ( p < 0.05). In conclusion, forest management such as UR, NDST, and DST decreased soil total P and available P, and transforming soil P fractions to available P will meet the P demand following management in the pine plantations of subtropical China., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer QZ declared a shared affiliation with the authors ZJ, LZ, LL, CL, YS, JZ, WX to the handling editor at the time of review., (Copyright © 2024 Jian, Zeng, Lei, Liu, Shen, Zhang, Xiao and Li.)

Secondary cloud forests (SCFs), those that regenerate naturally following abandonment of human activities in previously deforested land, are of great value as refuges of high species diversity and for their critical role in hydrological regulation. This opinion paper analyzes the main environmental, socio-economic, and regulatory aspects that currently hamper the sustainable use and conservation of SCFs in Mexico for the provision of timber and ecosystem services. The main constraints identified include contradictory norms and policies and the marginalization of smallholders in timber production activities. Developing economic incentives for forest product harvesting and provision of ecosystem services derived from SCFs, while also addressing legal and normative aspects related to their sustainable use, is paramount. Given the high heterogeneity in floristic composition and stand structure of SCFs among localities, technical and social norms for sustainable use should be sufficiently flexible to allow adaptive management approaches. Future research areas should be focused on monitoring the response of SCFs to silvicultural interventions, documenting existing traditional practices as well as conducting socio-economic analyses of timber production and associated ecosystem services. This is essential for developing sound policies and approaches for the sustainable use and long-term management of SCFs in Mexico. [ABSTRACT FROM AUTHOR]

Chronic disturbance is widely recognized as one of main triggers of diversity loss in seasonally dry tropical forests (SDTFs). However, the pathways through which diffuse disturbance is acting on the forest are little understood. This information is especially demanded in the case of vanishing Neotropical seasonally dry forests such as the Tumbesian ones. We proposed a conceptual model to analyze the factors behind the loss of woody species richness along a forest disturbance gradient, explicitly considering the existence of direct and indirect causal pathways of biodiversity loss. We hypothesized that the chronic disturbance can act on the woody species richness directly, either by selective extraction of resources or by browsing of palatable species for livestock, or indirectly, by modifying characteristics of the forest structure and productivity. To test our model, we sampled forest remnants in a very extensive area submitted to long standing chronic pressure. Our forests cells (200 × 200 m) were characterized both in terms of woody species composition, structure, and human pressure. Our structural equation models (SEMs) showed that chronic disturbance is driving a loss of species richness. This was done mainly by indirect effects through the reduction of large trees density. We assume that changes in tree density modify the environmental conditions, thus increasing the stress and finally filtering some specific species. The analysis of both, direct and indirect, allows us to gain a better understanding of the processes behind plant species loss in this SDTF.

The soil carbon pool holds an enormous amount of carbon, making it the largest reservoir in the terrestrial ecosystem. However, there is growing concern that unsustainable logging methods damage the soil ecosystem, thus triggering the release of soil carbon into the atmosphere hence contributing to ongoing climate change. This study uses a replicated (n = 4) logging experiment to examine the impact of supervised logging with climber cutting (SLCC) and conventional logging (CL) on basic soil characteristics, litter input to soils, soil carbon pools, and soil respiration in a mixed dipterocarp forest 26 years after logging. This study found that there was no significant difference observed in the soil physicochemical properties and total carbon pools between the logging treatments and the virgin forest. Soil carbon pools dominated the total carbon pools, and the highest mean value was recorded in SLCC (87.95 ± 13.67 Mg C ha−1). Conventional logging had a lower mean value (71.17 ± 12.09 Mg C ha−1) than virgin forest (83.20 ± 11.97 Mg C ha−1). SLCC also shows a higher value of soil respiration rate (161.75 ± 21.67 mg C m−2 h−1) than CL (140.54 ± 12.54 mg C m−2 h−1). These findings highlight the importance of accurate quantification of the effect of different logging methods on the forest’s carbon pools.

Forest logging detection is important for sustainable forest management. The traditional optical satellite images with visible and near-infrared bands showed the ability to identify intensive timber logging. However, less intensive logging is still difficult to detect with coarse spatial resolution such as Landsat or high spatial resolution in fewer spectral bands. Although more high-resolution remote sensing images containing richer spectral bands can be easily obtained nowadays, the questions of whether they facilitate the detection of logging patterns and which spectral bands are more effective in detecting logging patterns, especially in selective logging, remain unresolved. Therefore, this paper aims to evaluate the combinations of visible, near-infrared, red-edge, and short-wave infrared bands in detecting three different logging intensity patterns, including unlogged (control check, CK), selective logging (SL), and clear-cutting (CC), in north subtropical plantation forests with the random forest algorithm using Sentinel-2 multispectral imagery. This study aims to explore the recognition performance of different combinations of spectral bands (visual (VIS) and near-infrared bands (NIR), VIS, NIR combined with red-edge, VIS, NIR combined with short-wave infrared bands (SWIR), and full-spectrum bands combined with VIS, NIR, red edge and SWIR) and to determine the best spectral variables to be used for identifying logging patterns, especially in SL. The study was conducted in Taizishan in Hubei province, China. A total of 213 subcompartments of different logging patterns were collected and the random forest algorithm was used to classify logging patterns. The results showed that full-spectrum bands which contain the red-edge and short-wave infrared bands improve the ability of conventional optical satellites to monitor forest logging patterns and can achieve an overall accuracy of 85%, especially for SL which can achieve 79% and 64% for precision and recall accuracy, respectively. The red-edge band (698–713 nm, B5 in Sentinel-2), short-wave infrared band (2100–2280 nm, B12 in Sentinel-2), and associated vegetation indices (NBR, NDre2, and NDre1) enhance the sensitivity of the spectral information to logging patterns, especially for the SL pattern, and the precision and recall accuracy can improve by 10% and 6%, respectively. Meanwhile, both clear-cutting and unlogged patterns could be well-classified whether adding a red-edge or SWIR band or both in VIS and NIR bands; the best precision and recall accuracies for clear-cutting were enhanced to 97%, 95% and 81%, 91% for unlogged, respectively. Our results demonstrate that the optical images have the potential ability to detect logging patterns especially for the clear-cutting and unlogged patterns, and the selective logging detection accuracy can be improved by adding red-edge and short-wave infrared spectral bands.

Abstract Background Riparian forests surrounding streams host high biodiversity values, but are threatened by clear-cut logging. Narrow buffer strips of about 15 m are commonly left between the stream and the clear-cut, but studies suggest that the buffer width should be at least 30 m to protect riparian plant communities. Moreover, selective logging is often allowed on the buffer strips in order to increase economic gain. We used an experiment of 43 riparian sites where buffer strip width and selective logging within the strip were manipulated and supplemented with unlogged control sites. We report the short-term changes in the community composition of vascular plants and mosses near the stream (0–15 m distance). Results 15-meter buffers are not enough to protect the vascular plant communities from changes caused by a clear-cut irrespective of the selective logging on the buffer strip. For moss communities 15-m buffers were not enough if they were selectively logged. Relative to the control sites, we observed no significant changes in community composition of vascular plants or mosses in the sites with 30-m buffer strips, whether selectively logged or not. Conclusions We conclude that buffer strips of 15 m are not sufficient to protect streamside plant communities even in the short term, but that buffers of 30 m should be left on both sides of the stream. Selective logging appears not to have effects on buffers that are at least 30 m wide. Thus, it may be more reasonable to increase buffer width and to allow selective logging on the wider buffer in order to compensate for the economic losses than to leave all trees on a narrow and ecologically insufficient buffer.

Climate change and habitat degradation are amongst the two greatest threats to biodiversity. Together, they can interact to imperil species. However, how climate change and land‐use change jointly affect the demographic vital rates that underpin population viability remains unknown. Here, using long‐term data on birds from the increasingly degraded and rapidly warming Himalayas, we show that survival trends over time are linked to species' elevational ranges in primary, but not in selectively logged forest. In primary forest, populations at their cold‐edge elevational range limit show increases in survival rates over time, whereas those at their warm‐edge elevational range limit suffer survival declines. This pattern is consistent with species tracking favorable climatic conditions over time, leading to improved demographic outcomes at progressively higher elevations with climate change, which in turn lead to upslope range shifts. In logged forest, however, survival rates remain relatively constant over time. This suggests that, in response to climate change in the long term, individuals of the same species can maintain demographic vital rates in higher‐elevation primary forest, but not in logged forest. This is the first demonstration of how two of the most disruptive anthropogenic influences on biodiversity interact to threaten survivorship in natural populations. Ignoring interactions between climate change and land‐use change can potentially undermine accurate forecasting of the future of species in an increasingly warm and degraded world. Importantly, large tracts of well‐protected primary forests across Earth's tropical elevational gradients may be essential to enable tropical montane species to persist in the face of climate change. [ABSTRACT FROM AUTHOR]