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Logging is a dominant land-use activity across the tropics and a significant source of greenhouse gas emissions. This study quantifies emissions from selective logging in a Forest Stewardship Council (FSC) certified concession in Guyana that includes carbon in extracted logs, tree carbon left in the forest, and incidental tree mortality caused by felling and logging infrastructure. We also estimate carbon emissions from sawmilling of round logs. Emissions from harvested trees from stump to mill gate were 8.44 Mg CO2 m−3 (131.96 Mg CO2 ha−1). The main sources of emissions were from trees killed during felling (34%) and unextracted biomass of harvested trees (32%). On average, 15.5% of the harvested tree biomass and 43% of the log biomass was converted to sawn lumber (0.78 Mg CO2 m−3 of round log volume). We find similar levels of logging emissions in our study with those reported for non-FSC concessions in Guyana (8.54 Mg CO2 m−3) and Suriname (8.94 Mg CO2 m−3) but higher in two FSC-certified concessions in Suriname (6.65 Mg CO2 m−3). Adopting forest management practices that reduce residual stand mortality from felling and improved milling technology to reduce wood waste will help meet future demand for wood products and support climate mitigation goals. [ABSTRACT FROM AUTHOR]

Active foraging of tree branches for light and space can result in crown asymmetry. By opening canopy gaps, selective logging may increase the prevalence of trees with asymmetrical crowns and the extents of their asymmetries. Crown asymmetry is relevant to forestry insofar as it may stimulate bole curvature, decrease the range of angles over which trees can be directionally felled, increase rates of natural tree fall, and create dangerous conditions for forest workers. In a forest in Guyana that was selectively logged 23 years prior to our study, we evaluated the asymmetries of crowns of trees on the boundaries of mapped felling gaps. For 192 trees ≥ 20 cm diameter, we measured crown radii into and away from 56 canopy gaps. Assuming that tree crowns were symmetrical at the time of gap creation, we estimate the rate of lateral crown expansion into gaps as the difference between crown radii into and away from the canopy opening. We then compared apparent rates of lateral crown expansion into gaps by tree species, gap size, and stem diameter growth rates. We found that 83% of tree crowns were wider on the gap side than into the closed canopy forest, with crowns on average 2.1 m wider towards canopy gaps. Rates of gap-ward crown extension were faster among long-lived light-demanding pioneer species than in more shade tolerant climax species. Among trees ≥ 20 cm diameter at the time of gap creation, stem growth rates are positively but only weakly correlated with crown asymmetry. [ABSTRACT FROM AUTHOR]

Aim of study: To compare the diversity and biomass of logged forests, with different ages after harvesting and the risk of their degradation to liana forests. Area of study: We studied 18 plots at the central zone of the Imataca Forest Reserve (Guayana shield), Venezuela. Material and methods: We used 1-ha plots, to measure individuals with dbh > 10 cm in control plots (0 years) and in logged plots with 3, 9, 12, 15 and 18 years after logging. The main variables evaluated were enlarge importance index (EII), richness (R), Shannon-Weaner index (H´), Alpha Fischer (α), basal area for commercial species (BA_comm), above-ground carbon (C) and lianas abundance at the understory (Lianas_%Au). Main results: Diversity variables (R: 62-77 spp ha-1, p: 0.117-0.838; H´: 2.8-3.4, p: 0.181-0.677; α: 18.6-25.4, p: 0.293-0.922) and biomass (89.6-180.2 MgC ha-1, p: 0.171-0.895) did not have significant differences between control and most of the logged plots. Only the 18 years-old forests had statistically higher values of diversity (R: 81-94 spp ha-1, p: 0.000; H´: 3.8-3.9, p: 0.000; α: 26.8-31.7, p: 0.000), perhaps due to a high impact skidding operation. Commercial species were not recovering after logging. Research highlights: Forest management can be viable in this area, but it requires reduced impact logging techniques and better silvicultural systems to guarantee future harvest of high value commercial timber.

• Potential of a drone-borne lidar system to assess the outcomes of a mixed-species restoration plantation experiment. • Brazil's Atlantic Forest, with 20 native tree species, combining two levels of planting density and two management levels. • We elaborate an AGB equation to use the drone-borne lidar for monitoring other restoration plantations in the region. • Leaf area density profile (lidar-derived) also differed among silvicultural treatments. • Drone-borne lidar system can effectively monitor forest restoration plantations. We are in an unprecedented moment for promoting forest restoration globally, with international and regional pledges to restore at least 350 million hectares by 2030. To achieve these ambitious goals, it is necessary to go beyond traditional plot-scale assessments and develop cost-effective technologies that can monitor the structure and function of restored forests at much broader scales. Lidar remote sensing in unmanned aerial vehicle (UAV) platforms can be an agile and autonomous method for monitoring forest restoration projects, especially under conditions when information updates are frequently needed in relatively small areas or, when using an airplane-borne lidar system may be not financially viable. Here, we explored the potential of an UAV-borne lidar system to assess the outcomes of a mixed-species restoration plantation experiment, designed to maximize aboveground biomass (AGB) accumulation. The experiment was established in Brazil's Atlantic Forest, with 20 native tree species, by combining two levels of planting density and two management levels, totaling four treatment combinations and one control (plots left over for natural regeneration). We analyzed three structural variables from lidar data (canopy height, gap fraction and leaf area index) and one from field inventory data (AGB). Structural differences between the treatments and the control plots were reliably distinguished by the UAV-borne lidar system. AGB was strongly correlated with canopy height, allowing us to elaborate a predictive equation to use the UAV-borne lidar system for monitoring structural features in other restoration plantations in the region. UAV-borne lidar systems showed enormous potential for monitoring relatively broad-scale (thousands of hectares) forest restoration projects, providing an important tool to aid decision making and accountability in forest landscape restoration. [ABSTRACT FROM AUTHOR]

Highlights • We established baselines for carbon emissions from selective logging in Peru. • No difference in emissions were observed between certified and uncertified concessions. • Despite trees with short stems and large crowns, Peru has among the lowest emissions. • Unintended carbon emissions could be reduced by half. • The majority of emissions came from the felled tree itself and very few from roads. Abstract Forests in southwestern Amazonia are increasingly being converted for agriculture, mining, and infrastructure development; subjected to low-intensity selective logging of high value timber species; and designated as conservation areas and indigenous reserves. To understand the impacts of forestry in this region, we evaluated carbon emissions from felling, skidding, and hauling in five FSC-certified concessions where workers were trained in reduced-impact logging (RIL) and in four non-certified concessions where workers were not trained in RIL in Madre de Dios, Peru. Emissions estimates did not differ by certification status, so we established a single baseline for selective logging emissions. Total carbon emissions from selective logging were low per hectare (4.9–11.6 Mg ha−1) due to low logging intensities (2.9–8.1 m3 ha−1). Despite the unique architecture of trees in the southwestern Amazon (short stems and large crowns), emissions per volume and per ton carbon in the extracted timber were also relatively low (1.55 Mg m−3 and 4.04 Mg Mg−1, respectively). Only emissions per area scaled with logging intensity. Emissions were dominated by the felled tree itself (in extracted logs and residuals), whereas hauling infrastructure (roads and log landings) contributed comparatively little. Unintended emissions could be reduced by 46% if concessions were able to achieve the best demonstrated outcomes in each source category and by 54% with additional improvements. Less than 5% of timber was lost due to hollow sections. We determined that it would be overly cautious to avoid cutting all trees with any hollow sections, and it would actually increase emissions per unit timber extracted if no other trees were cut in place of the hollow trees. At the tree level, certified concessions had higher log recovery and damaged fewer commercial species during felling, which should increase their current and future timber yields. It is important to both understand and improve carbon dynamics in managed forests in this emerging hotspot for greenhouse gas emissions from deforestation and forest degradation. [ABSTRACT FROM AUTHOR]

Highlights • We quantified baseline selective logging emissions in DRC, Gabon and Republic of Congo. • Selective logging transfered up to 9% of live AGB and BGB tree carbon biomass into necromass. • No significant difference between FSC and non-certified concessions. • Logging emissions represented 40% of total emissions from deforestation. • Implementing RIL-C practices can cut half of emissions without reducing timber yields. Abstract To estimate carbon emissions from selective logging in Central Africa, we employed the reduced-impact logging for carbon emissions reductions (RIL-C) protocol to quantify baseline carbon emissions from legal timber harvests by source (i.e., hauling, skidding, and felling). We modeled the relationships between emissions and biophysical conditions, logging practices, and forest policies and then used these models to estimate potential emission reductions from full implementation of RIL-C practices. We applied the method in 8 forest management enterprises (FMEs; i.e., concessions) in the Democratic Republic of Congo (DRC), 9 in Gabon, and 6 in the Republic of Congo (RoC). Committed logging emissions expressed per cubic meter of timber harvested (to control for differences in logging intensities) ranged from 0.63 Mg C m−3 in a FME in RoC to 4.8 Mg C m−3 in a FME in Gabon, with an overall average of 2.1 Mg C m−3. Logging emissions were dominated by damage caused by road and log landing construction (i.e., hauling; 50%) and felling (43%; includes carbon in extracted logs). Total emissions represented only about 9% of unlogged forest biomass carbon stocks. Average emissions were highest in Gabon (2.65 Mg C m−3) followed by DRC (1.84 Mg C m−3) and RoC (1.54 Mg C m−3). Emissions from concessions certified by the Forest Stewardship Council (FSC, N = 6) and those that were not certified (N = 17) did not differ. Nearly half (51%) of logging emissions could be avoided without reducing timber yields if all best examples of RIL-C logging practices observed were applied in the same FME. At the country level, if all FMEs were to utilize these practices, emissions reductions would be 34% in RoC, 45% in DRC, and 62% in Gabon. When combined with country-level logging statistics, emissions from selective logging as currently practiced in the six countries of the Congo Basin are equivalent to 40% of the region's total emissions from deforestation. [ABSTRACT FROM AUTHOR]

Various international bodies and non-governmental organizations (NGOs) have proposed guidelines for safeguarding biodiversity. Nevertheless, quantitative criteria for safeguarding biodiversity should first be established to measure the attainment of biodiversity conservation if biodiversity is to be safeguarded effectively. We conducted research on the impact of logging on biodiversity of dung beetles and small mammals in a production forest in Temengor Forest Reserve, Perak, Malaysia. This was done to develop such quantitative criteria for Malaysian production forests while paying special attention to the effects of road networks, such as skid trails, logging roads, and log yards, on biodiversity. Species assemblages of dung beetles as well as small mammals along and adjacent to road networks were significantly different from those in forest interiors. Therefore, minimizing the road network density will contribute to retaining biodiversity; this will allow us to use road network density as a quantitative criterion for safeguarding biodiversity in production forests. Additionally, road network density is easily measurable and verifiable by remote sensing, which enables us to check the implementation of the criteria.

Forest management of tropical lowland and hill wet evergreen forests traditionally assumes that succession, species composition, and forest structure are largely driven by small, frequent disturbances. More recent ecological studies, archaeological findings, palynology and climate records demonstrate that tropical rainforests in general are not only subject to treefall disturbances but also to large-scale, infrequent disturbances driven by both past ancient and more recent human land use, and by natural forces of climate and geology. This paper reviews the case for the presence and extent of large-scale infrequent disturbances in Mesoamerica. We then use this knowledge to understand effects shaping species composition and structure. We evaluate current silvicultural regeneration systems for forest management based on the gap dynamics paradigm and propose potential alternative and complementary regeneration methods for forests and tree species that are driven by large-scale disturbances. We propose that the shade-intolerant timber species observed today are in large part a reflection of legacies of human land use and historical large-scale disturbances. Such species require larger, more dramatic disturbance regimes to regenerate and to attain the canopy in future managed forests. We suggest that such conditions are not provided for by current silvicultural systems within the region that require multiple entries to the stand every 15–30 years and should be coupled with liberation thinnings to promote shade-tolerant, commercially valuable timber species. Alternative silvicultural systems, such as shelterwoods and seed-tree methods of regeneration and management, purposefully promote the regeneration of valuable, shade-intolerant timber species. We propose applications for reserve design, and the management of non-timber forest products in conjunction with timber products to compliment such activities. These systems differ in their goals, species promoted (shade-tolerant vs. –intolerant) and the ecological assumptions driving their operations. We conclude that shelterwoods and seed-tree systems are more appropriate to manage forests rich in shade-intolerant timber species. Such methods need to be included in the suite of silvicultural options available to managers of tropical wet evergreen forests in Mesoamerica. [ABSTRACT FROM AUTHOR]

To assess the impacts of a low-intensity selective timber harvest on a palm community in Belize, we mapped logging infrastructure (i.e., roads, log landings, skid trails, and stumps) and measured palm regeneration 1 year after a timber harvest carried out using reduced-impact logging (RIL) practices. We sampled palms across a gradient of increasing harvest impact severity from areas not directly affected by logging, in felling gaps, on secondary and primary skid trails, and on log landings. We used generalised linear mixed-effect models fitted in a Bayesian framework and applied a non-metric multi-dimensional scaling of the ecological distances between sites to evaluate differences in palm seedling regeneration density and species composition, respectively. The harvest of an average of 2.5 trees ha −1 caused 0.4% of the forest to be converted to log landings, 0.7% and 3.6% to roads and skid trails, and 2.3% to felling gaps, which left 93.0% of the 350 ha harvest block with no direct impacts of logging. The difference in abundance and species composition of palm regeneration in unlogged areas compared to felling gaps and skid trails was small, but log landings had markedly lower densities. These results highlight that the impacts of selective logging are minor at least where harvest intensities are low and RIL practices are employed. If further reductions in canopy opening and soil disturbance are desired, we recommend that logs be cable-yarded (i.e., winched) the final 20 m to skid trails instead of driving to the tree stumps. We estimate that implementation of this practice would reduce total skid trail coverage from 3.6% to 2.9% and overall forest disturbance from 7.0% to 6.3%. However, further reductions in disturbance might be inimical to the maintenance of palms and will certainly not favour regeneration of light-demanding commercial timber species (e.g., Swietenia macrophylla ). [ABSTRACT FROM AUTHOR]

Current Mexican forest management is the product of a history that dates back to 1926. Earlier approaches were directly or indirectly aimed at attaining the normal forest model. Around 1980, multi-resource and environmental impact considerations were mandated for all private timber operations. Timber-oriented silviculture was deemed insufficient to take proper care of non-timber values in the forest. Concerns about water quality, biodiversity, and natural conservation were the motives for promoting voluntary best management practices, in 2012 and afterwards. In this research, two traditional Mexican forest management schemes, Sicodesi and Plan Costa, enhanced with best management practices, are compared to Mapa, a management method specifically designed to manage landscape attributes. Results from two successive forest inventories 10 and 13 years apart show that Sicodesi and Plan Costa, even when modified to comply with best management practices, failed to maintain proper stewardship of non-timber values. Mapa, however, employed multiple means to drive forest dynamics to fulfill multi-resource objectives, constrained by self-financing and competitive profitability. These capabilities in Mapa enabled some degree of control over non-timber values, but many more important processes occur beyond the property boundary, and beyond the planning scope considered in Mapa and all other forest planning methods. [ABSTRACT FROM AUTHOR]

To develop silvicultural guidelines for high-value timber species of Central African moist forests, we assessed the performance of the pioneer Milicia excelsa (iroko, Moraceae), and of the non-pioneer light demander Pericopsis elata (assamela, Fabaceae) in logging gaps and in plantations in highly degraded areas in south-eastern Cameroon. The survival and size of each seedling was regularly monitored in the silvicultural experiments. Differences in performance and allometry were tested between species in logging gaps and in plantations. The two species performance in logging gaps was significantly different from plantations and concurred with the expectations of the performance trade-off hypothesis but not with the expectations of species light requirements. The pioneer M. excelsa survived significantly better in logging gaps while the non-pioneer P. elata grew significantly faster in plantations. The high mortality and slow growth of M. excelsa in plantations is surprising for a pioneer species but could be explained by herbivory (attacks from a gall-making psyllid). Identifying high-value native timber species (i) with good performance in plantations such as P. elata is of importance to restore degraded areas; and (ii) with good performance in logging gaps such as M. excelsa is of importance to maintain timber resources and biodiversity in production forests. [ABSTRACT FROM AUTHOR]

Highlights: [•] We monitored above-ground tree (AGB) biomass of 18–1ha plots after logging in Eastern Amazon for 8years. [•] The mortality of large trees (DBH>60cm), was found to drive the annual ABG net changes. [•] The over mortality of large trees injured by logging were the main causes of biomass loss. [•] To improve the AGB balance after selective logging, we recommend the preservation of the biggest trees (DBH>110cm). [•] REDD+payment could be used to compensate the lost of benefits, and to promote sustainable logging. [Copyright &y& Elsevier]

Most tropical forests outside protected areas have been or will be selectively logged so it is essential to maximize the conservation values of partially harvested areas. Here we examine the extent to which these forests sustain timber production, retain species, and conserve carbon stocks. We then describe some improvements in tropical forestry and how their implementation can be promoted. A simple meta-analysis based on >100 publications revealed substantial variability but that: timber yields decline by about 46% after the first harvest but are subsequently sustained at that level; 76% of carbon is retained in once-logged forests; and, 85-100% of species of mammals, birds, invertebrates, and plants remain after logging. Timber stocks will not regain primary-forest levels within current harvest cycles, but yields increase if collateral damage is reduced and silvicultural treatments are applied. Given that selectively logged forests retain substantial biodiversity, carbon, and timber stocks, this 'middle way' between deforestation and total protection deserves more attention from researchers, conservation organizations, and policy-makers. Improvements in forest management are now likely if synergies are enhanced among initiatives to retain forest carbon stocks (REDD+), assure the legality of forest products, certify responsible management, and devolve control over forests to empowered local communities. [ABSTRACT FROM AUTHOR]

Analysing data from 903 permanent sample plots situated in medium-moist and moist forests in the southern Cape, South Africa, we explored factors controlling forest structure. Pronounced subcanopy stem density persistence (well-stocked subcanopy forest matrix) and stem density packing (comparatively high stem densities of relatively large-sized trees) were found in the moist, less seasonal (quasi-tropical) Tsitsikamma forests. These attributes of structure were linked to the prevailing dystrophic, less seasonal conditions and the associated metabolic vertical growth orientation. The cool, moist and seasonal (quasi-temperate) Knysna forests had lower densities of relatively large-sized trees at the canopy level (stem density intolerance). This was attributed to the lateral growth mode and extended persistence of the trees involved. The warm, seasonal (quasi-subtropical) Outeniqua forests, on relatively nutrient-rich soils, had high stem densities at the canopy level relative to the subcanopy stratum; due to a combination of low subcanopy tree persistence, fast ingrowth of trees into the canopy stratum, which were then lost to mortality before they reached large sizes (high canopy tree turnover). Persistence of the multi-species subcanopy forest matrix supported asynchronous establishment and death of individual trees. Typical for tropical-type forests, the development of trees towards maturity (phase) was associated with a spatially fine-grained disturbance regime. A metabolic performance trade-off model was developed and provided an ecophysiological framework for the interpretation of forest structure and its underlying dynamics. This explanatory model indicated causal links between intraspecific metabolic tactics of trees in response to their edaphoclimatic environment and associated attributes of forest structure. Some implications of the findings for tropical forest management are discussed. [ABSTRACT FROM AUTHOR]

The effects of proximity to felling gaps on residual trees in a selectively logged forest were monitored for eight years after nine 4-ha plots (n = 3 per treatment) were subjected to one of two intensities of reduced-impact logging (RIL), i.e. either 50 or 60 cm diameter cutting limits, or conventional logging of 60 cm diameter cutting limit with three additional plots reserved as unlogged controls. Each residual tree > 10 cm diameter at breast height (dbh) was classified as either being near (< 20 m from a gap centre) or far (> 20 m) from the nearest felling gap, defined as 20 m radii areas around the stumps of felled trees. Tree mortality rates did not vary with gap proximity, but were higher in logged than unlogged plots for the first two years after logging. In all logged plots combined, trees < 50 cm dbh of all species and dipterocarps < 30 cm dbh grew faster if they were near a gap. The observed increased growth rates of trees in the more intensively logged plots, regardless of the logging method used, was due to both higher proportions of trees near gaps and faster growth of trees in all locations. [ABSTRACT FROM AUTHOR]

Abstract: Changes in above-ground biomass (AGB) of 17 1ha logged plots of terra firme rain forest in the eastern Amazon (Brazil, Paragominas) were monitored for four years (2004–2008) after reduced-impact logging. Over the same time period, we also monitored two 0.5ha plots in adjacent unlogged forest. While AGB in the control plots changed little over the observation period (increased on average 1.4Mgha−1), logging resulted in immediate reductions in ABG that averaged 94.5Mgha−1 (±42.0), which represented 23% of the 410Mgha−1 (±64.9) present just prior to harvesting. Felled trees (dbh>55cm) accounted for 73% (±15) of these immediate losses but only 18.9Mgha−1 (±8.1) of biomass was removed in the extracted logs. During the first year after logging, the annual AGB balance (annual AGB gain by recruitment and growth−annual AGB loss by mortality) remained negative (−31.1Mgha−1 year−1; ±16.7), mainly due to continued high mortality rates of damaged trees. During the following three years (2005–2008), average net AGB accumulation in the logged plots was 2.6Mgha−1 year−1 (±4.6). Post-logging biomass recovery was mostly through growth (4.3±1.5Mgha−1 year −1 for 2004–2005 and 6.8±0.9Mgha−1 year −1 for 2005–2008), particularly of large trees. In contrast, tree recruitment contributed little to the observed increases in AGB (1.1±0.6Mgha−1 year−1 for 2004–2005 and 3.1±1.3Mgha−1 year−1 for 2005–2008). Plots with the lowest residual basal area after logging generally continued to lose more large trees (dbh ≥70cm), and consequently showed the greatest AGB losses and the slowest overall AGB gains. If 100% AGB recovery is desired and the 30-year minimum cutting cycle defined by Brazilian law is adhered to, current logging intensities (6treesha−1) need to be reduced by 40–50%. Such a reduction in logging intensity will reduce financial incomes to loggers, but might be compensated for by the payment of environmental services through the proposed REDD (reduced emissions from deforestation and forest degradation) mechanism of the United Nations Framework Convention on Climate Change. [Copyright &y& Elsevier]

Abstract: Tropical forests could satisfy multiple demands for goods and services both for present and future generations. Yet integrated approaches to natural forest management remain elusive across the tropics. In this paper we examine one combination of uses: selective harvesting of timber and non-timber forest product (NTFP) extraction. We analyze the current status of this combination and speculate on prospects and challenges regarding: (i) resource inventory, (ii) ecology and silviculture, (iii) conflict in the use of multipurpose tree species, (iv) wildlife conservation and use, (v) tenure, and (vi) product certification. Our conclusions remain preliminary due to the relative paucity of published studies and lessons learned on what has worked and what has not in the context of integrated management for timber and NTFPs. We propose at least three ways where further research is merited. One, in improving ‘opportunistic’ situations driven by selective timber harvesting that also enhance NTFP values. Two, to explicitly enhance both timber and NTFP values through targeted management interventions. Three, to explicitly assess biophysical, social, regulatory and institutional aspects so that combined benefits are maximized. Interventions for enhancing the compatibility of timber and NTFP extraction must be scaled in relation to the size of the area being managed, applied timber harvesting intensities, and the dynamics of multi-actor, forest partnerships (e.g., between the private sector and local communities). In addition, training and education issues may have to be re-crafted with multiple-use management approaches inserted into tropical forestry curricula. [Copyright &y& Elsevier]

As part of efforts to design appropriate silvicultural methods for sustainable forest management of big-leaf mahogany (Swietenia macrophylla: Meliaceae) in natural mixed forests of Quintana Roo, Mexico, a study of seed dispersal of 11 mahogany seed trees was undertaken. Both small (50-74 cm diameter at breast height, dbh) and large (75-100 cm dbh) seed trees showed seed distributions that were skewed to the west, generally matching the prevailing easterly trade winds. Total mean seed production of trees in the smaller size class was one-half of that of the large trees. Maximum seed dispersal distance was 50 m in the westerly directions (NW-W-SW) and only 20-30 m in other directions. Total seed dispersal areas were 0.4 and 0.5 ha for the small and large trees respectively. These results are important for designing seed tree or shelterwood regeneration methods for mahogany; they provide guidelines for creating the size and spatial layout of an overstorey felling and site preparation treatment that would match the dispersal area. [ABSTRACT FROM AUTHOR]

Abstract: Seeds of mahogany and Spanish cedar were planted in gaps created by harvesting railroad ties at two locations in the Yucatan Peninsula. Gaps averaged 40m2 in area. Germination after 2 months was very low (2%) for Spanish cedar and moderately low (29%) for mahogany at the one location where it was measured, probably due to predation and fungal damage. Annual seedling mortality was 25–40%, and height growth was moderate to normal, with average height equal to 45cm after 3 or 4 years, depending upon the location. We conclude that gaps from railroad tie harvesting are not adequate for the establishment of either species from seed. If, however, gaps created by harvesting could be concentrated into at least moderately open areas 400m2 in area or larger, they may be useful as sites for regenerating both species. [Copyright &y& Elsevier]

Abstract: Damage caused by reduced-impact logging (RIL) was assessed in 18 plots 1ha each in a terra firme rain forest of Eastern Amazon (Brazil, Paragominas). Mean logging intensity was 6treesha−1 and the resulting commercial volume 21m3 ha−1. On average, logging damage affected 16% of the original stand while skidtrails occupied 7% (661m2 ha−1) of forest soil area. Canopy openness doubled to a mean of 11%. Of the variables studied, “number of trees harvested or felled per plot” gave the best correlation to “proportion of damaged or destroyed trees”. Damage to each diameter class was distributed in accordance with relative abundance of trees (dbh≥20cm) in the original population before logging, suggesting that all diameter classes were affected equally. The sustainability of timber management applying RIL was evaluated through the calculation of the recovery level of commercial trees in three different scenarios. In the most optimistic scenario (growth rate of 5mmyear−1 and 1% annual mortality), after 30 years, only 50% of the commercial stand would recover, provoking a drastic reduction of the harvesting intensity at the second felling cycle. Within a 30-year felling cycle (i.e. the legal felling cycle duration in the Brazilian Amazon) and even under RIL systems, the present logging intensity occurring in the study area (6treesha−1) is not compatible with sustainable yield production on a long-term basis. For the study area, only the implementation of silvicultural treatment ensuring that the remaining potential crop trees grow at 4–5mmyear−1 would guarantee a logging intensity of 3–4treesha−1 (10–14m3 ha−1) 40 years after the first harvest. This study showed that in the Amazon, RIL alone is clearly not sufficient to achieve sustainable forest management. More sophisticated silvicultural systems must be urgently elaborated and implemented to ensure that the forest will still be sustainably managed on a long-term basis. This issue is particularly important in the case of Brazil as a new law allowing the creation of 500,000km2 of forest concessions by 2010 has been recently approved by the congress. [Copyright &y& Elsevier]