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In a time of global change, having an understanding of the nature of biotic and abiotic factors that drive a species' range may be the sharpest tool in the toolbox of conservation and management of threatened species. However, such information are lacking for most tropical and epiphytic species due to the complexity of life history, the roles of stochastic events, and the diversity of habitat across the span of a distribution. In this study, we conducted repeated census across the core and peripheral range of Trichocentrum undulatum, a threatened orchid that is found throughout the island of Cuba (species core range) and southern Florida (the northern peripheral range). We used demographic matrix modeling and stochastic simulations to investigate the impacts of herbivory, hurricanes, and logging (in Cuba) on projected population growth rates (λ and λs) among sites. Our study indicates that the Florida population is under high extinction risk and most populations in the core range show less interannual variability, but, with the exception of one population, are also in decline. The peripheral population experienced higher herbivory damage than did the core populations, by a native inflorescence‐crippling fly, Melanagromyza miamensis, and an invasive, mortality‐triggered scale, Diaspis boisduvalii. The latter was found in the Florida population only. Hurricanes increased levels of mortality and had a negative effect on λ. However, λ increased following hurricane events due to increased recruitment and decreased herbivory. Life table response experiments suggest that higher adult survival was the largest contributor to the higher λ observed in the growing Cuba populations, as compared with the population in Florida. Logging simulations in Cuba indicate that populations can maintain stability only if selective logging of host trees occurs at low frequency. Reintroduction of the species in its northern peripheral habitat is needed to ameliorate the threats from sea‐level rise and invasive herbivorous insects to secure the current species' northern, continental range margin. Our study exhibits how vital rates and ecological interactions vary across a species distribution and respond under differing stochastic events. [ABSTRACT FROM AUTHOR]

Abstract In a time of global change, having an understanding of the nature of biotic and abiotic factors that drive a species' range may be the sharpest tool in the toolbox of conservation and management of threatened species. However, such information are lacking for most tropical and epiphytic species due to the complexity of life history, the roles of stochastic events, and the diversity of habitat across the span of a distribution. In this study, we conducted repeated census across the core and peripheral range of Trichocentrum undulatum, a threatened orchid that is found throughout the island of Cuba (species core range) and southern Florida (the northern peripheral range). We used demographic matrix modeling and stochastic simulations to investigate the impacts of herbivory, hurricanes, and logging (in Cuba) on projected population growth rates (λ and λs) among sites. Our study indicates that the Florida population is under high extinction risk and most populations in the core range show less interannual variability, but, with the exception of one population, are also in decline. The peripheral population experienced higher herbivory damage than did the core populations, by a native inflorescence‐crippling fly, Melanagromyza miamensis, and an invasive, mortality‐triggered scale, Diaspis boisduvalii. The latter was found in the Florida population only. Hurricanes increased levels of mortality and had a negative effect on λ. However, λ increased following hurricane events due to increased recruitment and decreased herbivory. Life table response experiments suggest that higher adult survival was the largest contributor to the higher λ observed in the growing Cuba populations, as compared with the population in Florida. Logging simulations in Cuba indicate that populations can maintain stability only if selective logging of host trees occurs at low frequency. Reintroduction of the species in its northern peripheral habitat is needed to ameliorate the threats from sea‐level rise and invasive herbivorous insects to secure the current species' northern, continental range margin. Our study exhibits how vital rates and ecological interactions vary across a species distribution and respond under differing stochastic events.

While several studies have been conducted on the impacts of logging on forest recovery in tropical forests, most of these studies have largely focused on short term forest recovery and without perspectives on how different logging intensities could influence the nature and extent of forest recovery in the long term. This study therefore aims to explore how varying site conditions, resulting from the creation of different disturbance types (skid trails and felling gaps) following selective logging at two logging intensities influenced long-term floristic composition eighteen years after logging. The study was conducted in the permanent sample plots located in a 134-ha compartment in the Pra-Anum Forest Reserve. Data collection was conducted on 160 recording plots distributed on three disturbance sites and an unlogged area, within two blocks of logging intensity of 26.32 m3/ha and 52.63 m3/ha (representing the volume of trees harvested per hectare). Results showed that the main skid trail had significantly lower species abundance and richness than the other disturbance types and the unlogged area. There was also a significant difference in species spatial distribution across all the four sites. These distribution patterns revealed differences in plant dominance at disturbance gradients, which indicate their success at competing for available resources within their niche space. Furthermore, the number of species belonging to particular ecological guilds classified from the different skid trails and unlogged areas as well logging intensities showed no significant variation. However, most of the species sampled across the disturbance regimes and unlogged area were observed to be shade tolerant. Logging disturbance and logging intensity did not influence the distribution of trees of national conservation importance (based on tree distribution, ecology, local abundance, interaction with ecosystem parameters and economic importance which have been used as basis conservation prioritization). However, disturbance type and higher logging intensities favoured tree species of minimal timber and national conservation importance, relative to the unlogged area. Given the increasing demand for timber products for both domestic and international markets, which is driving higher harvesting intensities legally and illegally, this study will inform forest management decision making on the long term dynamics of tree species recovery following logging.

Trees in the Garden Route National Park ( GRNP) indigenous forests in South Africa are selectively harvested for timber based on criteria that include signs and symptoms induced by wood-rotting fungi. However, virtually nothing is known regarding the identity and host associations of these macro-fungi in this natural ecosystem. Surveys were conducted in three harvesting compartments in the GRNP to investigate the taxonomic affiliation and species richness of these fungi on standing and recently harvested trees. Samples were collected from basidiomes on infected trees and tree stumps, and from diseased tissues on symptomatic trees. Phylogenetic analyses using ITS sequences characterized the isolates obtained into 26 Operational Taxonomic Units ( OTUs) belonging to 17 genera after clustering the sequences at a 97% identity threshold. Ganoderma (Ganodermataceae) and Inonotus (Hymenochaetaceae) were the most species-rich genera and the Bloukrans compartment, with 22 OTUs, showed the highest species richness. A fungus ( OTU1) affiliated with Ganoderma pfeifferi was the most abundant in the surveyed areas. Its predominance was also evidenced on host trees since it occurred on 15 of the 20 tree species sampled, with Olea capensis subsp. macrocarpa (Oleaceae) being the most colonized host. Given the wide variety of wood-rotting basidiomycetes revealed by this study and particularly the preponderance of species with pathogenic potential, more attention should be given to better understand their ecological role in this natural ecosystem as well as the effects of logging that may enhance their dissemination or negatively affect their diversity and the health of trees in the region. [ABSTRACT FROM AUTHOR]

The factors that determine the existence of tropical forests dominated by a single species (monodominated forests) have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees ≥2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02) and 12 years (L-12) prior to sampling and an unlogged forest (ULF). Our results showed that L-02 stands had lower species richness (25 species) than the L-12 and ULF stands (49 and 46 species, respectively). As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/m²) than in the L-02 and L-12 stands (0.322 and 0.466 seedlings/m², respectively). However, seedling mortality was higher in the ULF stands (54%) than in the L-02 (26%) and L-12 (15%) stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions. Rev. Biol. Trop. 62 (1): 347-357. Epub 2014 March 01. [ABSTRACT FROM AUTHOR]

Nearly all forests in the Venezuelan alluvial plains are converted to agricultural lands. However, in forest reserves, logging is a selective extraction activity that disturbs part of the ecosystem. This work was aimed at studying floristic composition changes over longer periods of time in a forest with different logging intensities. We measured 11 plots distributed in random block design of 1 ha each. The importance value index (IVI) was calculated for all species and was used in a canonical correspondence analysis to evaluate species behaviour. Cecropia peltata and Inga sp. dominated the first successional stage attaining a maximum IVI close to 12 years but showed clear decline thereafter. The next successional phase was dominated by late secondary species such as Triplaris americana and Guazuma ulmifolia. Climax species such as Pouteria reticulata and Pachira quinata showed drastic reduction in importance and very slow recovery. This study was based on 16-year-observation period, a rare work which could make use of such long period of direct observation. Our results could be used to guide ecological restoration in deforested areas. Forest management strategies should be redrawn to make it a sustainable option. [ABSTRACT FROM AUTHOR]

The article presents a study on the impact of logging to aboveground live biomass in rainforests lowland areas at the Makapa concession in Papua New Guinea. It applied modified Bitterlich plotless technique to quantify aboveground live biomass of logged and unlogged regions. Results show that the regions have a mean aboveground carbon loss of 35 ± 2.8 Megagram per hectare. It adds that the plotless technique was efficient in estimating the logging damage and mean aboveground biomass.

Abstract: One of the main threats to the sustainability of community forestry in the Selva Maya is insufficient regeneration of commercial tree species. We evaluated the regeneration status of 22 commercial tree species in a managed semideciduous tropical rain forest in Southern Mexico. The study was carried out in six harvesting areas along a 16-year chronosequence. In each area, 10 transects (1000m2) were established and all trees >50cm height and <10cm diameter were recorded. We evaluated the relationships between seedling and sapling abundance, and canopy cover and disturbance condition (closed forest, canopy gap, log landing, skid road, primary road and secondary road). The area occupied by closed forest canopy increased with age of harvesting area (65–91% of sampled area), while the area occupied by canopy gaps decreased (22–9%). Log landings occupied less than 1% of the sampled area. The predominant canopy cover was 75–80% in all harvesting areas, even in the most recently harvested areas. The highest densities of seedlings and saplings, of both shade tolerant and intolerant species, were found in log landing and skid trails, followed by secondary roads. Even Simarouba glauca, a shade tolerant species, displayed higher densities in sites with ≤65% of canopy cover. Our results support previous findings and indicate that the levels of disturbance caused by existing harvesting procedures may be inadequate to promote sufficient regeneration of not only light demanding desirable species but also for some of the evaluated shade tolerant species of commercial interest. Seedling and sapling densities exhibited by Swietenia macrophylla, for example, are insufficient to support current harvesting rates. The application of a spatial mixed system with patch-cuts of different sizes, a consequence of group felling, could be applied to provide the necessary conditions for the regeneration of the main commercial species. [Copyright &y& Elsevier]

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A comparison of landslide rates following helicopter and conventional, cable-based, clear-cut logging was carried out using results from two independent terrain attribute studies in the Eldred and Lois River watersheds in the Southwest Coast Mountains of British Columbia. Landslides initiating from directly within a road prism were excluded from the study in order to focus the comparison on landslides related primarily to conventional versus helicopter yarding methods. A landslide rate of 0.02 landslides/ha was observed in 162 terrain polygons logged by helicopter ∼8 years prior to this study. Landslide rates in 38 gullied polygons were 0.06 landslides/ha. No landslides were observed in 124 open-slope polygons. Over a similar 8-year average period, 0.03 landslides/ha were observed in 142 cable-yarded terrain polygons; 0.06 and 0.02 landslides/ha occurred in gullied and open-slope polygons, respectively. t-Tests indicate that total landslide rates are not significantly different following helicopter and conventional logging; however, a dichotomy exists between gullied and open-slope terrain polygons. Landslide rates are not significantly different in gullied terrain but are significantly higher on open-slopes following conventional cable logging. Consequently, landslides appear to have a greater potential to occur in open-slope terrain following conventional logging, but differences in gullied polygons are less likely. Increased post-logging landslide rates in conventionally logged, open slopes are more likely the result of undetected road-related drainage changes than differences between helicopter and conventional yarding-related ground disturbance. [Copyright &y& Elsevier]

The assessment on key ecological factors affecting runoff and soil erosion and the usefulness of plot-level monitoring of soil erosion was conducted by collecting runoff and soil loss records from 14 runoff plots. The runoff plots were set up in two catchments in Central Kalimantan, Indonesia, where conventional logging and Reduced Impact Logging (RIL) took place. Runoff plots were set up in forest areas with different levels of logging disturbances, i.e. harvesting areas (four plots), skid trails (six plots), and undisturbed/control areas (four plots). The magnitude of runoff and soil loss from skid trail plots were found to be the highest, followed by control plots and harvest plots. Canopy cover, sapling density, litter depth and woody debris appeared to be important ecological factors that determine the magnitude of soil loss. Tree canopy determines the size and erosive power of the raindrops. Sapling, litter layer, and woody debris protected soil surface, thus preventing soil detachment, and provided surface roughness that minimised soil particle movement down the slope. The roles of these ecological factors were less significant compared to rainfall in determining the magnitude of runoff.Canopy cover, sapling density, litter depth and woody debris can be measured quantitatively or qualitatively without complicated equipment and methods. Furthermore, they are sensitive to logging disturbance which make them suitable verifiers of soil erosion. Forest managers need to limit disturbance to these factors in order to minimise soil erosion in their logging operation areas. Monitoring of soil loss using runoff plots was cost-effective and provided valuable information about soil erosion risks caused by logging operations. Runoff plots clearly demonstrated site disturbances where the plots are located. Monitoring allowed more direct linkages to be made between management practices and their impacts on runoff and soil erosion, thereby enabling forest managers to identify problems and take appropriate preventive measures to improve their management practices. [Copyright &y& Elsevier]

Nesting habits of highly social stingless bees (Meliponini) were studied in lowland dipterocarp forests in Sabah, Borneo. A total of 275 nests of 12 species of bees were located. All nests were closely associated with living (91.5%) or dead (8.5%) trees, either within pre-formed cavities in the trunk (cavity nests) or situated in or under the tree base (base nests). Species of bees differed in nesting habit. The majority of species (seven) were cavity nesters, but the majority of nests (81%) were base nests. Nests were often aggregated (mean of 1.94 nests/nest tree), with up to eight colonies and three species in a single tree. Nest trees were mostly large to very large (86.1% above 60 cm dbh) commercial timber trees; 47.3% of nest trees were dipterocarps. According to visual inspection nest trees were of significantly lower expected timber quality then randomly chosen control trees. Taking into account information on tree species, size and expected timber quality, we estimated that 34.0 or 42.6% of nest trees were potential harvest trees, depending on harvesting regulations (reduced impact logging (RIL) versus conventional). Lower percentages under RIL guidelines were mostly due to size restrictions that protect very large trees (>120 cm dbh). Harvesting is likely to kill bee colonies associated with the respective tree. Therefore, and because meliponine colonies are long-lived and have low fecundity, direct impact from logging may have lasting effects on bee populations. Harvesting guidelines that retain high proportions of large and hollow trees should be promoted in order to preserve meliponine pollination in sustainable forest management. [Copyright &y& Elsevier]

The effects of logging damage on forest dynamics processes were assessed in a lowland dipterocarp forest of East Kalimantan, Indonesia. From 1990 to 1991, twelve 4 ha plots (200 m×200 m) each divided into four 1 ha subplots were set up and all trees with dbh ≥10 cm measured and identified at least at the generic level. Logging was carried out from November 1991 to March 1992 in nine plots while three plots served as control. The 48 subplots were grouped according to the proportion of remaining basal area after harvesting, as follows: group 1 with more than 80% of the original basal area remaining, group 2 with 70–79%, group 3 with less than 70%, and group 4 as control plots. Remeasurements were carried out just after logging in 1992 and then every 2 years until 1996. Felling intensity varied from 1 to 17 stems ha−1 (50–250 m3 ha−1). In primary forest, mean annual mortality remained constant to 1.5% per year throughout the study period while mean annual mortality rate was significantly higher in logged-over forest (2.6% per year). This higher rate resulted from a higher mortality of injured trees (4.9% per year). Four years after logging, mortality rates in logged-over and primary forest were similar. Recruitment remained constant at 8 trees ha−1 per year in primary forest and varied from 14 to 32 trees ha−1 per year in logged-over stand in proportion with the amount of damage. In stands with the lowest remaining basal area, the establishment and growth of dipterocarps was strongly limited by the strong regeneration of pioneer species. This study suggests that total basal area removed by logging in primary forest (harvested trees and trees killed during felling and skidding) should not exceed 15% of the original one; reduced-impact logging (RIL) techniques applied with a maximum harvesting intensity of 8 trees ha−1, can keep logging damage under this threshold. [Copyright &y& Elsevier]

Three hundred and sixty three landslides in three watersheds that totaled 382 km2 were identified from air photographs, beginning at a date that preceded logging to the present. The three watersheds all lie on Vancouver Island; however, they have different precipitation regimes, topography, and amounts logged. Landslide areas in the watersheds varied in size from 200 m2 to more than 1 ha. Nearly 80% of the landslides were debris slides; 15% were debris flows, and the remainder primarily rock falls. Following logging, the number of landslides increased substantially in all watersheds although the amount of increase was variable: approximately 11, 3, and 16 times in Macktush Creek, Artlish River, and Nahwitti River, respectively. Other analyses of changes in landslide density also produced highly variable results, with the number of landslides increasing between 2.4 and 24 times. Further, 2–12 times more landslides reached streams following logging activities. Densities for landslides impacting streams increased for the period of record from 1.5 to 10 times following logging activities. The densities were substantially greater where only landslides that reached streams since development began in a watershed were considered. Roads had the greatest spatial impact in the watersheds (compared to their total area), with frequencies determined to have increased by 27, 12, and 94 times for Macktush, Artlish, and Nahwitti, respectively. The results highlight the relative impact of roads and their role in slope stability. [Copyright &y& Elsevier]

The conservation status of the sun-tailed guenon Cercopithecus solatus, which is endemic to central Gabon, is assessed using the most recent information available. The known range of the species covers 11,000–12,000 sq km, an area with a sparse human population but where the logging activity is widespread. There is no evidence of a recent reduction of the population size of this monkey, mainly because trees are extracted at a low rate (1–2 trees/ha), which does not cause a significant change in the forest composition and structure, and because hunting pressure is currently low. Moreover, the species is suspected to be able to thrive in degraded secondary forests. Consequently, the sun-tailed guenon does not appear to be under immediate risk of extinction. The conservation actions undertaken to date are described and the threats that may affect the monkey in the near future are discussed. Commercial bush-meat hunting is considered to be the most serious threat for the species. Recommendations for the conservation of wild populations and habitat are proposed, and emphasis is placed on co-operation with the forestry companies that are the main economic actors in the species's range. [ABSTRACT FROM AUTHOR]

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