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Background Tree-related microhabitats (hereafter, “TreMs”) are key components of forest biodiversity but they are still poorly known in North American hardwood forests. The spatial patterns of living trees bearing TreMs (hereafter, “TreM-trees”) also remain to be determined. As logging practices can lead to a loss of TreM-trees and of their associated biodiversity, it is essential to identify the factors explaining TreM occurrence to better integrate them into forest management. We therefore inventoried TreMs in 4 0.5-ha survey strips in northern hardwood forests in Quebec, Canada, while recording the spatial location of each tree. Two strips were located in unmanaged old-growth forests, and 2 were in forests managed under selection cutting. All 4 stands were dominated by sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrn.). Beech bark disease, an exotic pathology, was observed in all the strips. Results Large diameter at breast height and low tree vigor were the main characteristics explaining the presence of TreMs at the tree scale. TreM-trees presented slight spatial aggregation patterns. These aggregates, however, were not well-defined and were generally constituted by a large number of trees bearing few different types of TreMs. Two TreM classes (broken branch or top and woodpecker lodge) also presented a spatial aggregation. Logging practices had no significant effect on TreM occurrence. Beech bark disease increased the frequency of senescent beeches. The impact of this pathology on TreMs was however mitigated by the small size of infected trees and probably by the short time elapsed since its appearance. Conclusion The factors explaining the presence and abundance of TreMs on trees has so far been little studied in North American hardwood forests. Our results highlight that TreM-tree characteristics in the surveyed forests are consistent with those of previous studies conducted in other forest types and regions (e.g., Europe or Northwestern America). To our knowledge, this study is also the first to identify a spatial aggregation of TreM-trees and of specific TreM classes. It will be nevertheless necessary to determine whether the small impact of logging activities we observed results from current or past management practices.

Traditional silvicultural systems such as clearcutting and single-tree selection cutting are critiqued for their tendency to simplify forest complexity. By more closely emulating natural disturbance regimes and increasing the availability and heterogeneity in understory light levels, we pose that systems causing intermediate disturbances such as the single-tree and small group selection cutting system can promote tree regeneration, retain stand structural attributes, and maintain high understory plant diversity in temperate mixedwood stands. To assess this, we implemented a harvest intensity gradient experiment (residual basal area [BA], % removal) consisting of uncut control (26 m2/ha, 0%), light (21 m2/ha, 20%), moderate (18 m2/ha, 31%) and heavy (15 m2/ha, 42%) cutting with retention of legacy trees in uneven-aged yellow birch (Betula alleghaniensis Britton) – conifer stands. We evaluated the effects on gap size, light transmittance, abundance of living and dead trees, plant diversity, and regeneration of target species (i.e. yellow birch, red spruce [Picea rubens Sarg.] and balsam fir [Abies balsamea L.]), during the 8 years postcut. Moderate and heavy single-tree and small group selection cutting treatments triggered changes in microenvironments and in understory plant community. Moderate and heavy selection had greater yellow birch seedling density > 30 cm in height compared to the control. Cutting treatments did not significantly improve red spruce and balsam fir regeneration, despite favorable micro-environmental conditions (e.g. gaps averaging 200–350 m2 and 15–40% transmitted light). The vascular plant community rebounded quickly after disturbance and harvesting did not depress any diversity metric or alter community composition beyond control levels. Tree species richness increased in moderate and heavy selection cuts, while vascular species diversity (H′) was greatest in the heavy selection cut. Observed richness and diversity gains were driven by augmented yellow birch and mountain maple (Acer spicatum Lam.) recruitment into larger classes as well as greater forb, tree, and shrub cover in response to greater cutting intensities. Species richness and diversity were positively correlated with increased light availability, but not with light heterogeneity. Our results show that this hybrid selection cutting system benefits yellow birch recruitment without negatively impacting plant diversity. However, because increasing harvest intensity simultaneously enhanced interfering non-commercial species abundance (e.g. mountain maple), failed to improve red spruce regeneration, and decreased the abundance of large trees (diameter at breast height > 29 cm), we caution to opt for moderate cutting intensity in this forest type. Additional treatments such as enrichment planting in harvest gaps might be necessary to maintain red spruce over time.

Gap dynamics is the main process by which forest renewal happens in many forest biomes in the world. Under the classical gap dynamics model, only canopy gaps are considered as a dynamic zone. It is also assumed that gapless canopy height change is either uncommon or unimportant for forest dynamics, even though its frequency has never been quantified. In the temperate deciduous forest biome of Quebec, Canada, forest management uses selection cutting to emulate gap dynamics, but little is known about the differences in canopy dynamics between unmanaged and managed forests. Here, we investigated five canopy height change processes: three generating positive height change (canopy growth, gap closure and gap filling) and two generating negative height change (gap creation and canopy height erosion) using multi-temporal LiDAR data in unmanaged and managed (by partial cutting) forests at different periods during the last 24 years. Canopy height erosion, which is canopy height reduction without gap formation, was very common in all studied forests, whatever the gap detection height thresholds used. This canopy process was often more frequent than new canopy gaps and as important in terms of canopy volume reduction. Gap closure rates suggest that canopy gaps will remain more frequent in managed forests 30 years after cuts compared to unmanaged forests. Our results show that it will take at least 30 years after cuts for natural canopy dynamics to recover. We also show that measurements of canopy dynamics processes are sensitive to canopy gap detection height thresholds. This sensitivity is clearly limiting the reproducibility and the comparability of studies in gap ecology.

Aboveground carbon (AGC) stock in forests is affected by several biotic and abiotic factors. Understanding those factors is crucial in managing forests for climate change mitigation and other ecosystem services. This study examined effects of diversity attributes (species and stand structural diversity of woody plants) and topographic attributes (altitude and slope) on AGC stock of a dry Afromontane forest. Data from individual woody plants for estimating AGC were collected from 252 plots (20 × 20 m) established in a systematic grid (2 × 2 km) covering the entire forest area. Woody plant diameter diversity and woody plant height diversity were used as proxies for stand structural diversity. Structural equation modelling was applied to test the effects of the selected attributes on AGC stock, and together they explained 71% of the variation. Stand structural diversity was the most important driving factor for the AGC stock. Woody plant species diversity had both direct and indirect effects on AGC stock, but the indirect effect through its influence on stand structural diversity was more pronounced. Altitude and slope were both negatively but weakly associated with AGC stock. Our results provide insight on the effects of diversity and topographic attributes on AGC stock, which can assist future management of the forest. Enhancing stand structural diversity by means of selection cutting systems and woody plant species diversity by means of enrichment planting can be effective treatments. When considering dry Afromontane forests’ widespread distribution, the potential contribution in carbon sequestration and thereby mitigating climate change is substantial. Hence, the results and management suggestions from the present study may have practical interest for the management of dry Afromontane forests not only in Ethiopia but also in Africa at large.

Emulating natural disturbance (END) patterns to conserve biodiversity is often a goal of forest management but the impact of forest cutting is still controversial. We examined effects on avian assemblages of partially-cut forest stands of 1–10, 11–20 and > 45 years (cut classes) post-harvest differing in the % basal area retained as wildlife species’ habitat in 85 shade-tolerant hardwood stands in Algonquin Park, Ontario. Permutational multivariate analysis of variance indicated significant compositional differences among cut classes, after controlling for year and township (spatial variation in surficial geology and topography), both of which were also significant. Pairwise comparisons indicated significant compositional differences only between young and old stands. The difference in beta diversity (homogenization/differentiation) among cut classes was marginally significant (P = 0.066). Pairwise differences were significant between old versus mid-aged cut classes, marginally significant for young versus old cuts, and non-significant for young versus mid-aged cut classes. Six species and cavity users as a group were more abundant in > 45 years post-harvest stands than in the other two cut classes. Six species had higher abundances in younger cuts than > 45 years post-harvest cuts. Red-eyed vireo (Vireo olivaceus) showed a nonlinear response and was least abundant in 11–20 year cuts. Blackburnian warblers Setophaga fusca, black-throated green warblers S. virens and pileated woodpeckers Dryocopus pileatus increased with the density of supercanopy trees (≥ 60 cm diameter at breast height - dbh) and in the case of pileated woodpeckers more large snags (≥ 40 cm dbh). Brown creeper Certhia americana abundance increased with greater basal area of trees ≥ 25 cm dbh and ovenbird numbers were significantly related to overall basal area. Chestnut-sided warbler S. castanea abundance decreased with an increase in overall basal area and was higher in the 1–10 year cuts and American redstarts S. ruticilla decreased with an increase in basal area. Our modelling suggests that effects of selection cutting systems on the avian community may be reduced as tolerant hardwood stands become regulated and have higher residual basal areas. Current guidelines in Ontario for the retention of large, scattered conifer trees appear to meet the requirements for most, but not all, species; however, guidelines for supercanopy trees are too low. These results indicate that the END paradigm for single-tree selection cutting in tolerant hardwoods may be partially effective but requires modifications, such as retaining higher densities of supercanopy trees that would be beneficial for birds.

Uneven-aged forest management is suggested to be a sustainable management alternative in boreal forests, but knowledge on applicable harvest intensities is very limited as majority of the studies has focused on even-aged management practices. The ecosystem model EFIMOD was used to assess the effect of selection cuttings on ecosystem production, carbon sequestration and volume increment in spruce stands. The model was calibrated and validated against experimental data from 20 permanent forest plots in southern Finland where stand responses to uneven-aged management had been monitored for 25 years. The simulated scenarios started with planting trees on bare land, simulation of first decades according to even-aged management, and a subsequent transformation into uneven-aged stand structure and management. Simulated selection cutting scenarios contained variations of both harvest interval (10–30 years) and postharvest stand density (basal area 8–16 m 2 ha −1 ). We hypothesized that longer harvest intervals and higher post-harvest basal areas will positively affect the net ecosystem production, nitrogen use efficiency, and forest carbon sequestration. The results presented here are for a period of 90 years. Simulations showed that net ecosystem production (NEP) increased from 0.25 to 0.5 kg m −2 a −1 of carbon with longer harvest intervals and higher postharvest density, and was generally less than that at undisturbed development. Nitrogen use efficiency (NUE) varied from 100 kg NPP per kg consumed N for heavy cuttings to 300 kg NPP per kg consumed N for light removal of trees. Changes in soil carbon stocks were negative for most scenarios (5–20% decline in terms of total soil C), and the decline was most pronounced with lowest postharvest density and short harvest intervals. The volume of harvested timber was between 320 and 400 m 3 ha −1 for a 60-year period. Longer harvest intervals resulted in increased timber production. Stem volume growth (5–7 m 3 ha −1 a −1 ) was equally affected by both harvesting parameters. The cumulative volume of deadwood of 80–120 m 3 ha −1 was substantially higher with the longest harvest interval (30 years) than with the shorter alternatives where it comprised 40–60 m 3 ha −1 . The simulations provide novel results on different harvesting options for uneven-aged forest management of boreal Norway spruce stands. These results fill a gap in knowledge on ecosystem responses to alternative management regimes and support the development of sustainable management practices.

Partial harvesting methods are generally more similar to the natural dynamics of broad-leaved forests than clear cutting. However, their effects on biodiversity are still poorly understood. We investigated the effects of selection cutting on the occurrence of a large epiphytic bryophyte, Neckera pennata, in a northern hardwood forest of New Brunswick, Canada. Twenty-eight forest stands were selected, representing two contrasting forest management practices: 5–9 years old, first-entry selection cuts and untreated stands that had been subjected to low-intensity single-tree cutting at least 35 years earlier. Within each stand, we quantified the presence–absence of N. pennata on 36 trees and measured selected forest stand variables. Although N. pennata had persisted in post-harvest stands, its frequency of occurrence on maple trees was only 7% there, compared to 39% in untreated stands. The density of large-diameter sugar maple trees and crown cover were the most important factors predicting the frequency of N. pennata at the stand level. Tree diameter was also a strong predictor of N. pennata’s presence at the tree level and the occupancy of large-diameter maples was almost twice as high in untreated stands as in selection cuts. However, the occupancy of large-diameter maples relative to smaller maple trees was much higher in selection cuts, possibly due to dispersal limitations resulting from reduced connectivity of large-diameter host trees. Taken together, our findings suggest that (1) large trees from older seral stages are a prerequisite for the long-term persistence of N. pennata in managed forests and that (2) they are therefore particularly important for managers to retain in selection cuts. Further, since our results indicate that reduced crown cover in selection cuts has a negative effect on N. pennata, the benefit of retaining large host trees would probably increase if buffered within retention patches of maturing trees. Finally, since host tree diameter clearly is a very important factor for the presence of N. pennata, any extension of the harvest rotation would be beneficial.

New forest edges are continuously being created by forest management. In the Swiss Alps, silvicultural treatments have partly changed from the selection cutting widespread two decades ago to a more intensive strip cutting. However, little is known about the impact of such harvesting on tree growth and on the structural development of Alpine forest stands dominated by Norway spruce (Picea abies (L.) Karst.), which have high economic and protective value. We therefore investigated the effect of strip cutting in four Alpine spruce stands differing in site and stand conditions through a dendrochronological analysis of 134 tree stems. The change in growth rate was assessed for the 10-year period before and after the cutting year, and rate changes in edge and non-edge trees were compared. The relative change in Hegyi’s competition index before and after the cut was used as a proxy for the change in space and related resources. A linear model was developed to assess the effects of biotic and abiotic variables on changes in growth after strip cutting. Radial growth responses varied greatly between the stands, with a significant increase only in edge trees in the two north-facing sites, i.e. 12% and 60%. Changes in tree competition had the strongest impact on tree growth, followed by site effects. With the same relative change in competition index, the radial growth of edge trees increased more strongly in reaction to cutting than that of non-edge trees. Additionally, small-diameter trees growing near edges benefited more from the strip cutting than larger trees. Our results suggest that strip cutting on north-facing slopes can boost the growth of trees on the east and north-east-facing forest edges. Small spruce trees growing along newly created forest edges can be kept to enhance stand yield. As cutting often leads to long forest edges and may thus affect the growth of a significant proportion of the forest area, such effects should be considered in planning cutting layouts.

Overyielding in mixed species stands is expected to vary with stand density, but only a few studies have quantified this. We used individual-tree growth data from permanent sample plots on 83 sites in Switzerland representing a three-species mixture between Norway spruce, Silver fir, and European beech. Basal area growth models for all three species indicated significant interactions between a competition index (CIs) and species composition in the neighborhood. The spatially-explicit CIs indicates stand density within a 10-m radius neighborhood, and the contribution of individual species to the CIs indicates the species composition. Given the rich vertical stand structure in the sample plots, which were often managed by single-tree selection cutting, it is not surprising that interactions between CIs and species proportion varied with relative tree height. We used the individual tree growth models to simulate stand growth with and without species composition effects. A sample plot with its real stand structure in terms of tree size and position was homogenized in terms of species composition at the tree level. By varying the stand density of this plot, we demonstrate how overyielding increases with stand density. In the given mixture, it is mostly beech contributing to the observed overyielding in dense mixed stands. Stand density therefore needs to be considered more explicitly when studying growth and yield of mixed species stands.

The success of partial cut applications to northern hardwood stands is based upon the contribution of harvested and residual trees to overall stand growth, which can be captured by a stand-level criterion, i.e, the growth dominance coefficient (GDC). The main objective of this study was to test the relevance of GDC in evaluating the success of partial cuts in even-aged and uneven-aged stands that were composed of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.). We first determined whether GDC that was calculated with two indicators of light capture, stem mass and tree leaf area, produced similar results after partial cutting in both stand structures. Second, using linear mixed models, we determined the effect of selection cutting on GDC in uneven-aged stands over the short- and medium-term, and evaluated effects of tree vigour and size before cutting on diameter growth response of trees after cutting. GDC based upon stem mass was similar to GDC based upon tree leaf area in even-aged stands (p = 0.7200), but was lower in uneven-aged stands (p

Although selection cutting has many advantages, its potential for damage to residual trees is a major challenge of forest management. The present study evaluated damage to residual trees during manual felling and cable-skidder logging operations in 18 instances of selection cutting in the Caspian forests of Iran. Data was collected from 100 m × 100 m systematic sample plots (0.1 ha) at each logging site. Harvest intensity ranged from 3.8 to 11 trees ha −1 and it averaged 7.3 trees ha −1 . Damage to residual trees was 10.5–23.6% with an average of 16.9%. There was a positive and significant correlation between amount of damage and harvest intensity ( R 2 = 0.65, P R 2 = 0.77, P 2 in size was the most common types of damage. Damage was concentrated in small diameter trees (DBH −1 , (2) limit selection cutting in slopes, less than 50%. Additional operational suggestions are implementation of felling direction and avoid log extraction through dense stands.

Partial harvesting during the snow-free season disturbs the forest floor and modifies seedbed characteristics. Quantitative information is lacking about the distribution of changes in seedbed proportions between areas located in and outside skid trails, and about how long these changes persist after harvest. These effects could interact with species’ seedbed requirements and seed input and influence spatio-temporal patterns of seedling establishment in forests, which would have important implications for regeneration dynamics. The objectives of this study were to determine how selection cutting affects seedbed proportions in and outside skid trails in northern hardwood stands, how these seedbed proportions vary over time following harvest, and how seedbed proportions in selection cuts compare with unharvested stand conditions. We sampled 12 sugar maple-dominated stands in southeastern Quebec, Canada. Two had not been harvested in the recent decades, while 10 had been harvested through selection cutting, 1–3 years earlier. A total of 3600 quadrats were sampled to determine the proportions of 8 seedbed types and whether or not a quadrat was located in a skid trail. This was the case for 24.1% of the quadrats in selection cuts. Outside skid trails, seedbed proportions in selection cuts did not vary from those in unharvested stands (P ⩾ 0.097). In these stands, leaf litter was the most abundant substrate, covering 87.3% of the forest floor, followed by rotten wood (4.9%) and fresh wood (3.0%). Humus, rocks and live tree bases occupied 1–2% the forest floor, while mineral soil and moss covered less than 1%. In selection cuts, proportions of rotten wood and live tree bases were lower in skid trails than outside, and this difference persisted 13 years after harvest. In 1- and 2-year-old cuts, the proportion of litter was lower in skid trails than outside, but not later on. The proportions of mineral soil and disturbed humus increased sharply in the skid trails after harvest (17.1-fold and 2.7-fold increases, respectively), but these effects lasted only 3 years for mineral soil and 1 year for humus. Power functions were used to model variation in litter, mineral soil and disturbed humus proportions as a function of time since harvest. We discuss the implications for regeneration dynamics of the marked, but short term increase in mineral soil and disturbed humus availability. Spatially explicit models that can simulate the mid- to long-term availability of substrates in both time and space would be useful for assessing the long-term implications of harvesting on seedbed proportions and regeneration patterns.

Forest management and associated litter inputs and decomposition rates are thought to affect the carbon storage in mineral soils. Here, we studied the effects of forest management on soil organic carbon (OC) stocks in density fractions of Ah-horizons in soils that developed on loess. We used 82 beech (Fagus sylv- atica L.) dominated forest plots in Thuringia, Germany that differed in their management (unmanaged forest, forests under age-class management and forests under selection cutting forest). After density frac- tionation of the mineral soil with a 1.6 g cm � 3 polytungstate solution we determined OC concentrations and stocks as well as CN-ratios in the free (f-LF) light fraction, the occluded (o-LF) light fraction and in the mineral associated organic matter (MOM) fraction. In our study, Ah-horizons of beech forests stored on average 2.6 ± 0.2 kg m � 2 (38.7 ± 1.3 kg m � 3 ) OC. The results showed that 37% of the bulk soil OC was stored in the light fractions. We could show that OC stocks in the light fraction were significantly affected by the amount of C stored in organic layers (p = 0.011). The OC stocks in the organic layers, in turn, were higher in unmanaged forests and in forests under selection cutting. This suggests a sensitivity of unpro- tected OC in the f-LF of beech forests against forest management. In contrast to the f-LF, the OC stocks in the MOM fraction are mainly controlled by pedogenic properties such as clay and iron oxide content. Even after several decades of forest management and with large sample size, an effect of forest manage- ment on the stable MOM fraction could not be detected.

Solar radiation, photosynthetically active radiation (PAR) and soil temperature were monitored during three summers following establishment of silvicultural gaps (1-ha square patch clearcut, 20- and 30-m diameter circular gaps) in yellow birch–conifer stands, in eastern Quebec, Canada (47°N latitude, 72°W longitude). We assessed the effect of aspect, slope, opening size, and location within the opening on the microclimate in a foothill site characteristic of this forest type. Daily solar radiation averaged 9.7, 14.3, and 15.1 MJ/m2 in the patch clearcut, in 2001, 2002, and 2003, respectively, as compared to 1.7, 2.2, and 2.8 MJ/m2 in the understory of the uncut forest. We also determined that the ratio of PAR to broadband solar radiation was quite constant in the patch clearcut (1.67 mol/MJ), while it increased from 0.76 mol/MJ (June–September) to 1.49 mol/MJ (October) in the forest understory, as broadleaved trees in the main canopy lost their foliage. Circular gaps received intermediate levels of solar radiation (3.9, 6.3, and 7.3 MJ/m2) that were comparable for the 20- and 30-m gap diameters. Solar radiation was consistently lower in the southern portion of these gaps than in their central and northern portions, a relative shortfall of 40–50% on north-facing aspects, and 25% on east-southeast aspects. This microclimatic diversity among locations was confirmed by PAR measurements and soil temperature monitoring, which suggests that differing ecological niches may promote species coexistence in these mixedwood stands.

We previously investigated the responses of forest birds to habitat changes 1–7 years post-harvest in three northern Ontario tolerant hardwood forest stands cut under the selection system. The same three cut blocks and a control area were re-sampled in 2009, 10–12 years post-harvest, to compare community composition, total and species abundances and species richness. We found that the breeding bird communities of the selection cut blocks had not fully recovered 10–12 years post-harvest. Veery, Chestnut-sided Warbler, Magnolia Warbler, American Redstart and Mourning Warbler numbers were elevated in all three cut blocks, and White-throated Sparrow numbers were elevated in two of the three cut blocks, 10–12 years post-harvest. In contrast, Ovenbird numbers remained depressed in two cut blocks 10–12 years post-harvest. Overall, species richness remained high in all three cut blocks, even though total abundance declined. The data suggest that repeated applications of selection cutting could have long-term, cumulative effects on forest bird communities.

The eastern Canadian boreal forest exhibits a specific disturbance regime where forest fires are less frequent than in the western part. This particularity may explain the abundance of irregular stands with distinct ecological features. To ensure sustainable forest management, these characteristics require the implementation of an adapted silviculture regime. In this context, two selection cutting methods were developed and compared with more conventional techniques, initially designed for cutting more regular stands of the boreal forest (cutting leaving small merchantable stems, careful logging preserving advance regeneration). The comparison focused on the capacity of treatments to maintain the primary attributes of irregular boreal forests, including complex vertical structure, abundant tree cover, species composition, and an abundance of dead wood. Mortality and regeneration processes were also compared. The experiment includes three sectors dominated by irregular black spruce (Picea mariana)-balsam fir (Abies balsamea) stands. Treatments were replicated in each sector in 0.25 ha plots. Stand characteristics were sampled pre-harvest and monitored for 3 years after cutting. Initial results indicate an important treatment effect on residual structure. Selection cutting maintains an inverse (irregular) J-shaped structure, typical of natural stands. Also, selection cutting does not seem to produce a significant effect on tree species composition (no undesired balsam fir enrichment) and does not modify the abundance of coarse woody debris. From a sustainable forest management perspective, the selection methods tested appear efficient in maintaining the main attributes and processes of the boreal irregular stands over the short term.

The conversion of even-aged Norway spruce (Picea abies (L.) H. Karst.) stands into more site adapted mixed stands is the main silvicultural goal in Germany and many other European countries. The conversion will primarily be achieved with the help of selection cutting, removing single target diameter trees and creating small gaps. At sites highly susceptible to windthrow, however, small scale clear cutting (up to 1 ha) might be an appropriate alternative. Both selection and clear cutting will affect the understorey vegetation, an important component of forest biodiversity and ecosystem functioning. Thus, with the help of a BACI-experiment (before–after/control–impact), the short-term effects of selection and small scale clear cutting on the herb and shrub layer vegetation were studied at two sites in the Solling Hills (Lower Saxony, Germany). Both treatments led to an increase in herb and shrub layer species numbers, due to persistent and invading (mainly pioneer tree species and indicators of disturbance) species and to a shift in plant traits. Most responsible for the changes in vegetation was a higher light availability, and to a lesser degree soil disturbance. The number of annuals and ruderals, however, increased only immediately after clear cutting, whereas on selection cutting plots the numbers remained high. Gaining in number and coverage were competitive perennials (Epilobium angustifolium, Juncus effusus, Rubus idaeus) especially on the clear cuttings, fulfilling a nutrient retention function. The competitives did not deter tree species from regenerating in the clear cut plots, whereas on selection cutting plots the large expansion of R. idaeus appeared to be hindering tree colonisation. Suffering under clear cut conditions were predominantly shade-tolerant, closed-forest species, but no loss of these species could be detected. This indicates the potential for a fast recovery of these forest species, as soon as, pioneer trees expand. Although the vegetation changed in similar directions at both study sites, differences in species numbers and composition were found, indicating the importance of site conditions in the beginning of succession. In conclusion, our study shows no overall negative effects on shrub and herb layer biodiversity and trait composition after clear cutting. It is suggested that small scale clear cutting may be considered an appropriate alternative to silvicultural methods which cause a moderate rate of disturbance, to reach the goal of Norway spruce forest conversion.

We examined the effect of management history on the availability of decayed downed wood and the use of downed wood as a regeneration substrate in mixed-species stands in the Acadian Forest of Maine. Regeneration of red spruce (Picea rubens Sarg.), eastern hemlock (Tsuga canadensis (L.) Carr.), balsam fir (Abies balsamea L. Mill), and red maple (Acer rubrum L.) was quantified. Treatments included variants of selection cutting, commercial clearcutting (unregulated harvesting), and no harvesting for >50 years (reference). Area of wood substrate (wood ≥ Decay Class III and ≥10 cm on at least one end) was less in the commercial clearcut than in the reference; other treatments were not differentiated. Spruce and hemlock seedlings were found at higher densities on wood than paired forest floor plots of equal area, regardless of treatment. Conversely, fir and maple were less abundant on wood than forest floor plots in reference and selection treatments, but more or equally abundant on wood than forest floor plots in the commercial clearcut. These findings suggest that silvicultural treatment affects both the availability of decayed downed wood and seedling-substrate relationships, and that forest management in the Acadian Region should consider availability of downed woody material.

This study assessed the sustainability of selection cutting in a community forest (CF) in Bhutan. The harvesting approach differed from cable crane logging operations in an adjacent commercially managed forest by creating much smaller canopy openings. This had many implications for natural regeneration of preferred species. The study was conducted in a late successional broadleaved CF containing 32 genera of tree species dominated by Quercus and Castanopsis and managed for timber, firewood, non-wood forest products and forest grazing. The study was based on a comparison of two forest inventories to assess forest structure and regeneration, a study of stumps to quantify harvesting intensities, and a household survey to quantify livestock holdings and grazing patterns. The study examined different intensities of selection cutting in three blocks of the CF and found that higher intensities of selection cutting did not have a negative impact on: (a) natural regeneration of seedlings and saplings of preferred timber species; (b) the diameter distribution of all species and use categories except for Quercus; (c) the diversity of tree genera; and (d) the percentage of remaining trees with favorable bole shape and form. These results contrasted with findings in the adjacent commercially managed forest. Community management of broadleaved forests with selection cutting appeared to be sustainable and avoid some of the unresolved silvicultural problems associated with commercially managed forests in Bhutan. However more research is needed on the sustainable management of Quercus spp.

Estimates of biomass integrated over forest management areas such as selective logging coupes, can be used to assess available timber stocks, variation in ecological status and allow extrapolation of local measurements of carbon stocks. This study uses fifty 0.1 ha plots to quantify mean tree biomass of eight logging coupes (each 450–2500 ha) and two similarly sized areas in un-logged forest. These data were then correlated with the spectral radiance of individual Landsat-5 TM bands over the 15 km x 15 km study area. Explanation of the differences in radiance between the ten forest sites was aided by measurements of the relative reflectance of selected leaves and canopies from ground and helicopter platforms. The analysis showed a marked variation in the stand biomass from 172 t ha-1 in coupe C88 that was disturbed by high-lead logging to 506 t ha-1 in a similarly sized area of protection forest. A two parameter linear model of Landsat TM radiance in the near-infrared (NIR) band was able to explain 76% of the variation in the biomass at this coupe-scale. The local-scale measurements indicated that the differences in the mean radiance of each coupe (in cloud-free areas) may relate to a change in the proportion of climax tree canopy relative to a cover of either pioneer trees or ginger/shrubs; the canopies of climax trees have the lowest NIR radiance of the vegetation characteristic of selectively logged forest. The coupe harvested following ‘Reduced Impact Logging’ guidelines had a residual biomass and NIR radiance more like that of undisturbed lowland dipterocarp forest than coupes disturbed by ‘conventional’ selection felling. The predictability of tree biomass (at the coupe-scale) by such a parsimonious model makes remote sensing a valuable tool in the management of tropical natural forests.

Biodiversity maintenance is a key management objective and a requisite for sustainable forestry. Research efforts on the effects of forest management on biological diversity are therefore increasingly needed, particularly in regions such as the Mediterranean that have been comparatively less studied in this respect. We analysed the effects of different regeneration and stand improvement treatments on six forest biodiversity indicators (snags, mature trees, shrub abundance, shrub species richness, tree species richness and tree species diversity) in the Mediterranean region of Catalonia (NE Spain) by analysing a set of 9808 plots from the Third Spanish National Forest Inventory comprising both managed and unmanaged stands. Managed stands had significantly fewer large-diameter trees (with the exception of Quercus suber forests) and snags than unmanaged ones. While clearcutting decreased tree species richness, stands with selection cutting had higher shrub and tree species richness and tree species diversity, which is consistent with the intermediate disturbance hypothesis, which states that diversity is highest at intermediate disturbance levels. Stand improvement treatments increased the number of large-diameter trees, tree species richness and diversity (cleaning and thinning), and shrub species richness (pruning), while no significant negative effect was found for any of the other indicators. Our results suggest that preventing silvicultural disturbances may not be the best solution for conserving and enhancing biodiversity in the Mediterranean forests of Catalonia, where many stands have high tree density that impedes the establishment of a variety of plant species and the transition to more developed stages. Selection cutting may be an appropriate and sustainable regeneration treatment for Mediterranean forests in this respect, buttheirpractical implementation shouldavoidthesystematicharvestingofthehighestqualityand largesttrees, whichisstill common in many private forests in Catalonia. # 2008 Elsevier B.V. All rights reserved.

We investigated immediate, medium and long-term effects of logging on arboreal lichen biomass in old-growth balsam fir forests (Abies balsamea (L.) Mill.) in the highlands of Quebec's Gaspe Peninsula using three complementary approaches. Firstly, we estimated the immediate loss of lichen biomass following logging and the annual lichen litterfall from remnant trees over 2 post-logging years. Treatments included selection cutting at three intensities (25, 30, 35%), diameter-limit cutting and cutting with protection of regeneration and soils (CPRS). Among studied treatments, we found that CPRS and diameter-limit cutting removed almost all the standing lichen biomass, while selection and partial cut allowed an immediate retention of ∼40–60% of the initial lichen biomass. Our results also suggested that the impact of logging on lichen litterfall rates were higher in silvicultural treatments (3–8.5%) compared to controls (1–2%); litterfall rates did not differ after 1 or 2 years post-treatment. Secondly, we evaluated medium-term effects by comparing pre-harvest fruticose lichen biomass data with data collected at the same site 4 years after experimental thinning operations. Mean fruticose lichen biomass did not change 4 years post-harvest. However, Bryoria spp. biomass did increase relative to Alectoria sarmentosa while Usnea spp. remained unchanged. Finally, the long-term logging effects were assessed by evaluating fruticose lichen biomass along a forest chronosequence in stands aged 30, 50, 70 and 90 years. Lichen biomass increased as a function of time for all genera, especially Alectoria. Logging activities result in direct losses of lichen biomass, but careful selection cutting that retains large lichen bearing trees and maintains post-harvest conditions not detrimental to lichen growth, particularly for Bryoria spp., can ensure a substantial biomass of lichens post-harvest. Such measures may ultimately contribute to maintaining woodland caribou herds that rely on arboreal lichens.

This study evaluated the impacts of partial cutting on stand characteristics, product recovery, and financial return in mature black spruce-balsam fir stands in Quebec. Four harvesting strategies (clearcut with advance growth protection, irregular shelterwood cutting leaving small merchantable stems, and two patterns of selection cutting) were each applied four times in 20 ha harvest blocks representing irregular black spruce-balsam fir stands. Before the four harvesting strategies were applied, there were no significant differences in stand characteristics (i.e., quadratic mean DBH, basal area, and merchantable stem volume) or expected product recoveries (i.e., lumber volume and value, chip volume and value, and total product recovery) estimated using the Optitek sawing simulation package. There was no significant difference in stand characteristics or product recovery values of the harvested stems between the selection cutting approaches (p > 0.05). However, significant differences in stand characteristics and product recovery values of the harvested stems existed between these treatments and both of the two other treatments. After cutting, the two selection cutting treatments had the lowest impacts on stand characteristics, as compared to the two other treatments. The selection cutting approach which used temporary skidding trails and where cutting was initially concentrated over half of the stand resulted in the highest benefit/cost ratio, relatively high net income and high total product value of residual trees.

The model of ‘ecological forestry’ has evolved as a part of the development of the concept of ecosystem management. ‘Ecological forestry’ emphasises that manipulation of a forest ecosystem should consider, and as far as practicable work within the limits of, natural disturbance patterns prior to extensive human alteration of the landscape. This paper evaluates the extent to which forest management practices in jarrah ( Eucalyptus marginata ) and karri ( Eucalyptus diversicolor ) forests of south-western Australia align with this view of the characteristics and appropriate silviculture of ‘ecological forestry’. Characteristics and appropriate silviculture of ‘ecological forestry’ are evaluated in relation to (i) the stand level decisions of stand structure and harvest timing and (ii) the landscape level decisions of harvest levels and age structures, and spatial patterns of harvest. Forest management in south-western Australia is found to align with appropriate silviculture under this model of ‘ecological forestry’. Additionally, the landscape triad of areas managed to ‘ecological forestry’ principles, conservation reserves and areas managed to production forestry is in place in the south-western forests of Australia. Strengths and weaknesses in the model of ‘ecological forestry’ and the ability to interpret consistency of practices in the forests of south-western Australia with the characteristics of ‘ecological forestry’ are identified.

Little is known about ponderosa pine forest ecosystem responses to restoration practices in the Northern Rocky Mountains, USA. In this study, restoration treatments aimed at approximating historical forest structure and disturbances included modified single-tree selection cutting, with and without prescribed burning. We compared the effectiveness of restoration treatments on growth, vigor, and composition of recruitment responses with untreated controls. We used a randomized block design to detect treatment differences in mean individual tree basal area increment (BAInc10), growth efficiency (GE), and recruitment abundance between two restoration treatments (Cut-only and Cut-burn) and a Control. We further examined treatment effects by tree age-class (Young, Mature, Presettlement) using a spatial ANOVA model that incorporates the spatial autocorrelation among trees within experimental units. Ten years after implementing restoration treatments, mean individual tree BAInc10 and GE were significantly higher for treated units relative to Control units; all three age-classes benefited similarly from restoration treatments relative to the Control, with the greatest response in the Cut-only and moderate response in the Cut-burn. When treated units were compared, Cut-burn negatively affected BAInc10 and GE relative to Cut-only. Presettlement trees responded positively to treatment relative to the Control, particularly for BAInc10, demonstrating the potential of these old trees to respond to reduced competition. The Cut-burn treatment, in contrast, negatively affected the BAInc10 and GE response of postsettlement trees when compared to Cut-only. Restoration treatments did not reduce the amount of Douglas-fir recruits. In addition, the recruitment of both ponderosa pine and Douglas-fir species was associated with the proximate cover of woody debris in Cut-only and Control treatments. Finally, special consideration needs to be taken for spring Cut-burn treatments, which appeared to dampen growth and vigor, relative to Cut-only, particularly for Young and Mature trees, and increased recruitment of ponderosa pine and particularly Douglas-fir.

We investigated the responses of forest birds to habitat changes following timber harvest by selection cutting in three northern tolerant hardwood forest stands using a before–after control-impact (BACI) type of experimental design. We observed only minor effects on the bird community associated with mature forests. Ovenbird ( Seiurus aurocapilla ) abundances declined by about 80–90% in two of the three harvested blocks. Black-throated blue warblers ( Dendroica caerulescens ) declined in abundance by about 70% on a single block 2 and 3 years post-harvest. Mechanical disturbance of the shrub layer [primarily Canada yew ( Taxus canadensis )] was coincident to this decline. Several bird species that prefer early successional or shrubby habitats, such as veery ( Catharus fuscescens ), cedar waxwing ( Bombycilla cedrorum ), chestnut-sided warbler ( Dendroica pensylvanica ), magnolia warbler ( Dendroica magnolia ), American redstart ( Setophaga ruticilla ), mourning warbler ( Oporornis philadelphia ) and white-throated sparrow ( Zonotrichia albicollis ), benefited from selection cutting, with the timing of individual species’ responses related to changes in habitat structure and composition. Effects in one block were still evident 7 years after harvest. Guidelines that support a residual stocking target of 20 m 2 /ha should promote the retention of mature forest bird communities, including ovenbird, while still providing habitat for early successional bird species.

The paper describes the recruitment pattern, structure and yield of Calabrian pine (Pinus nigra Arn. ssp.laricio Poiret var.Calabrica Delamare) stands on the Sila Plateau (Calabrian Region, Italy) that have been managed for over a century with a particular form of selection cutting. Management of these pine stands follows an unwritten plan which is based on a selection cut that is repeated approximately every 20 years on the same section of the forest. This type of management has preserved the typical forest landscape by maintaining a continuous forest cover. Age, dbh, height, diameter increment and spatial distribution of the trees were measured in a stand where the owner had marked trees for cutting according to traditional criteria. Results show that stand structure consists of very small clusters (60–100 m 2 ) of trees in four distinct age classes which are the result of the natural regeneration occurring in the gaps opened by the periodic removal of the biggest trees in the stand. The volume of harvested trees is slightly less than the volume increment for the average cutting cycle. The authors conclude that the description of truly traditional silvicultural systems, which have developed in different environments and with different techniques and often in contrast with established silvicultural methods, can make an important contribution to the search for ecologically, economically and socially sustainable ways of managing forests. # 2005 Elsevier B.V. All rights reserved.

Single-tree selection cutting is sometimes believed to be similar to the natural gap disturbance regime of hardwood forests, but few studies have specifically compared the compositional and structural characteristics of old-growth hardwood stands, undergoing natural gap dynamics and hardwood stands previously subjected to partial cuts. This study characterized and compared the composition (saplings and trees) and structure (gaps, foliage distribution, tree diameter and density, snags and coarse woody debris) of old-growth stands (OG), 12-year-old selection cuts (SC), and 28-33-year-old diameter-limit cuts (DLC) in sugar maple (Acer saccharum)-dominated northern hardwood stands. Results showed marked structural differences between OG and harvested stands, with stronger differences between DLC and OG than between SC and OG. The synchronized formation of numerous canopy openings in harvested stands induced a massive post-harvest recruitment of advance regeneration in both SC and DLC that created a dense foliage layer in the understory. Large living trees (dbh > 39.1 cm) and defective trees were less numerous in SC than OG, which can have a detrimental impact on species dependent on these structural elements, and on the future availability and characteristics of coarse woody debris. Relatively few compositional differences were noticed among stand types, although a greater proportion of mid-tolerant species was found in the post-harvest recruitment cohorts of harvested stands compared to OG, and a lower proportion of beech (Fagus grandifolia Ehrh.) saplings was observed in DLC compared to OG and SC. We argue that even if selection cutting is closer to the natural disturbance regime of hardwood forests than diameter-limit cutting, and therefore representing progress toward the development and implementation of a natural-disturbance-based management, a recurring application of selection cutting might lead to a homogenization of forest structure and composition, a reduction of key structural features and a reduction in biological diversity at both the stand and landscape scales. Some management recommendations are proposed.

Prior to Euro‐American settlement, dry ponderosa pine and mixed conifer forests (hereafter, the ‘‘dry forests’’) of the Inland Northwest were burned by frequent low- or mixed-severity fires. These mostly surface fires maintained low and variable tree densities, light and patchy ground fuels, simplified forest structure, and favored fire-tolerant trees, such as ponderosa pine, and a low and patchy cover of associated fire-tolerant shrubs and herbs. Low- and mixed-severity fires provided other important feedbacks and effects to ponderosa pine-dominated stands and landscapes. For example, in stands, frequent surface fires favored an ongoing yet piecemeal regeneration of fire-tolerant trees by periodically exposing patches of mineral soil. They maintained fire-tolerant forest structures by elevating tree crown bases and scorching or consuming many seedlings, saplings, and pole-sized trees. They cycled nutrients from branches and foliage to the soil, where they could be used by other plants, and promoted the growth and development of low and patchy understory shrub and herb vegetation. Finally, surface fires reduced the long-term threat of running crown fires by reducing the fuel bed and metering out individual tree and group torching, and they reduced competition for site resources among surviving trees, shrubs, and herbs. In landscapes, the patterns of dry forest structure and composition that resulted from frequent fires reinforced the occurrence of low- or mixed-severity fires, because frequent burning spatially isolated conditions that supported high-severity fires. These spatial patterns reduced the likelihood of severe fire behavior and effects at each episode of fire. Rarely, dry forest landscapes were affected by more severe climate-driven events. Extant dry forests no longer appear or function as they once did. Large landscapes are homogeneous in their composition and structure, and the regional landscape is set up for severe, large fire and insect disturbance events. Among ecologists, there is also a high degree of concern about how future dry forests will develop, if fires continue to be large and severe. In this paper, we describe the key landscape pattern and process changes wrought by the sum of the settlement and management influences to date, and we point to an uncertain future for ecosystem management. Widespread selection cutting of the largest and oldest ponderosa pine and Douglas-fir in the 20th century has reduced much of the economic opportunity that might have been associated with restoration, and long-term investment will likely be needed, if large-scale restoration activities are attempted. An

In the northern hardwood forest of northeastern North America, ecological and social perceptions call for forest management systems using reduced-impact silviculture such as single-tree selection cutting and small clearcuts. When applied over large areas, single-tree selection cut and small clearcut systems are likely to generate different local habitat structures and spatiotemporal habitat distribution in the landscape. This study assessed the effects of strip cutting and single-tree selection cutting on forest breeding birds when extensively applied in a northern hardwood forest in southwestern Quebec, a decade after timber harvest. Birds were surveyed twice during two consecutive breeding seasons by 270 point counts, equally distributed in a singletree selection cut forest, a strip cut forest, and an untreated forest. At each point count, habitat features and horizontal heterogeneity of these features were measured. Managed forest habitats had a much more developed understory, fewer snags and more downed woody debris. Horizontal heterogeneity was higher in the strip cut forest and lower in the single-tree selection cut forest. Of the 20 bird species analyzed, 13 showed a difference in abundance between at least two of the three treatments. Dendroica pensylvanica was mostly seen in the treated forests while Dendroica virens and Seiurus aurocapillus were more abundant in the untreated forest. Pheucticus ludovicianus was twice as abundant in the strip cut forest, while Catharus ustulatus was more frequently observed in the single-tree selection cut forest. Habitat vertical structure variables that differed among the three treatments were the most correlated with bird abundance. The results of this study support the use of a mix of silvicultural systems within the same forest in order to sustain habitat diversity for maintaining the regional avian cortege. # 2005 Elsevier B.V. All rights reserved.

The regeneration characteristics of Picea jezoensis Carr. and Abies sachalinensis Masters on cut stumps in natural forest under selection cutting and natural regeneration were studied in a sub-boreal forest of the Hokkaido Tokyo University Forest. The following points were investigated: (1) what decay class of cut stumps are suitable for regeneration of the two conifer species; (2) what part, either a root collar or a cut surface, of a cut stump is suitable for regeneration; and (3) what percentages of cut stumps support conifer seedlings. The percentages of cut stumps that supported conifer seedlings increased as the decay class advanced, but slightly decreased in the latest stage of decay class, V. Both P. jezoensis and A. sachalinensis seedling densities per cut stump and per square meter of cut stumps increased as the decay class advanced. Some root collars in decay class IV supported A. sachalinensis seedlings, but few supported P. jezoensis. Densities of P. jezoensis per cut surface and per square meter of cut surface in decay class IV were higher than those of A. sachalinensis. On the other hand, densities of A. sachalinensis per root collar and per square meter of root collar in decay class IV were higher than those of P. jezoensis. Cut stumps in advanced decay classes are more suitable for regeneration of P. jezoensis and A. sachalinensis than those in early decay classes. Whereas a cut surface is more suitable for regeneration of P. jezoensis, a root collar is more suitable for regeneration of A. sachalinensis. Cut stumps are not sufficient to ensure enough conifer regeneration because not all conifer cut stumps in advanced decay classes support conifer seedlings.

The effect of clearcutting, selection cutting, shelterwood cutting and microsites on soil surface CO2 efflux (SSCE) evolution was evaluated in a tolerant hardwood forest ecosystem in northern Ontario from May to November, 1998 using a LI-6200 dynamic, flow-through, portable, infrared CO2 gas analyzer. Selection and shelterwood cutting had the greatest effect, decreasing SSCE in September and October compared to control. SSCE from clearcut plots were intermediate between the control and other treatments. SSCE correlated strongly with soil temperature and weakly with soil moisture. Comparison of microsites disturbed by harvesting with those left undisturbed showed that SSCE was significantly lower on scarified microsites than on undisturbed microsites. Our results emphasize the importance of microsite distribution within harvested or otherwise treated areas, and may explain some of the discrepancies between several studies on the effect disturbed ecosystems have on SSCE.

We parameterized the light model of SORTIE for northern hardwoods in eastern Canada, and performed a sensitivity analysis and validation tests of the model before using it to predict the effect of various types of partial cutting on understorey light conditions. The parameterization was done by characterizing the crown geometry and openness of sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britt.), and beech (Fagus grandifolia Ehrh.). Those results indicated that beech casts a deeper shade than sugar maple and yellow birch. The sensitivity analysis showed that the model predictions were more sensitive to variations in the crown geometry parameters, especially the crown radius parameter, than to variations in crown openness. Validation tests of the model were performed in both mapped and unmapped plots by comparing light predicted by SORTIE to light measured in the field using hemispherical photographs and sensor-based measurements. In mapped stands, the model provided reasonably accurate predictions of the overall variation in understorey light levels between 2 and 30% full sunlight, but the predictions tended to lack spatial precision. In unmapped stands, SORTIE accurately predicted stand-level mean light availability at 5 m aboveground for stands ranging in basal area from 19 to 27 m2/ha. At heights lower than 5 m, SORTIE accurately predicted the light availability in a recent selection cut with a low density of understorey vegetation, but tended to overestimate light availability in stands with relatively dense undergrowth. Finally, a demonstration of the possible usefulness of the SORTIE light model is presented by using the model to compare the proportion of various light microsites created by a variety of selection cutting systems in use in eastern Canada (selection cutting with different harvesting intensities, group selection, and patch selection).

The objective of this study was to determine how canopy openness (CO) and light transmission are affected by selection cutting, and how they vary over time following harvesting in northern hardwood stands. We sampled five sugar maple—yellow birch—beech (Acer saccharum—Betula alleghaniensis—Fagus grandifolia) stands in Quebec (Canada). The stands had been logged, using the selection system, at different times (2–14 years) before the study, and were used as a chronosequence. We also sampled portions of each stand which had been kept as uncut controls. Ten 1 ha plots were sampled (five cuts and five paired controls). We took 20 hemispherical photographs per plot, at 5 m above-ground, which was above most understory vegetation. The CO, light transmission (gap light index (GLI) sensu Canham (1988)), sunflecks characteristics, and angular distribution of openings from the zenith were calculated for each photograph. Selection cutting increased CO, especially within 60 ◦ of the zenith. The greater CO in the cuts allowed a greater light transmission (GLI), longer sunflecks, and a longer cumulative daily sunflecks duration (CDSD). The differences observed between the cuts and the control plots in terms of CO, GLI, and CDSD were greatest in the more recent cuts, and decreased as a function of time since logging. The relationships were best described by negative logarithmic (CO) and negative exponential (GLI, CDSD) models. In the youngest cut (2 years old), the CO, GLI, and CDSD were on average 2.3–2.5 times higher than in the control, while in the oldest cut (14 years old), the same variables were 1.6–1.7 times higher than in the control. The results of this study emphasize the importance of taking into account the temporal variation in canopy openness and light transmission after canopy disturbances such as selection cutting because that variation will likely have an important influence on regeneration dynamics. © 2002 Elsevier Science B.V. All rights reserved.

This study investigated the effects of selection cutting on seedling densities of Picea jezoensis and Abies sachalinensis in the sub-boreal forests of the Hokkaido Tokyo University Forest. Volumes of, and coverage with, fallen logs, broken stems and snags in a preserve stand were significantly greater than those in a selection cutting stand. Regeneration substrates of P. jezoensis were limited to coarse woody debris and root mounds, whereas A. sachalinensis was found on coarse woody debris, root mounds, and soil. P. jezoensis seedling density on any regeneration substrate was not increased by selection cutting, whereas A. sachalinensis seedling densities on cut stumps and soil increased. An overall P. jezoensis seedling density in the preserve stand was significantly greater than that in the selection cutting stand, but there was no statistically significant difference in the densities of A. sachalinensis seedlings between the preserve and the selection cutting stands. The present study demonstrates that selection cutting in the sub-boreal forest of the Hokkaido Tokyo University Forest results in reduction of P. jezoensis seedling density because of reduction in coarse woody debris, the crucial regeneration substrate for P. jezoensis , and enhancement of A. sachalinensis regeneration on cut stumps and soil.

The purpose of this research was to develop a model that could be used to provide a spatial representation of uneven-aged silvicultural treatments on forest crown area. We began by developing species-specific linear regression equations relating tree DBH to crown area for eight bottomland tree species at White River National Wildlife Refuge, Arkansas, USA. The relationships were highly significant for all species, with coefficients of determination (r2) ranging from 0.37 for Ulmus crassifolia to nearly 0.80 for Quercus nuttallii and Taxodium distichum. We next located and measured the diameters of more than 4000 stumps from a single tree–group selection timber harvest. Stump locations were recorded with respect to an established grid point system and entered into a Geographic Information System (ARC/INFO). The area occupied by the crown of each logged individual was then estimated by using the stump dimensions (adjusted to DBHs) and the regression equations relating tree DBH to crown area. Our model projected that the selection cuts removed roughly 300 m2 of basal area from the logged sites resulting in the loss of ≈55 000 m2 of crown area. The model developed in this research represents a tool that can be used in conjunction with remote sensing applications to assist in forest inventory and management, as well as to estimate the impacts of selective timber harvest on wildlife.

The purpose of this study was to examine the effects of low intensity prescribed fires on wildfire hazard reduction, site preparation and tree mortality of uneven-aged managed ponderosa pine/Douglas fir ( Pinus ponderosa/Pseudotsuga menziesii ) forests. The study also provided the opportunity to determine the effects of uneven-aged silviculture on fire hazards. Burning followed the individual-tree selection cutting and full-tree utilization of an uneven-aged silvicultural prescription, which was developed for two stands in western Montana, U.S.A. Prescribed burning, following the full-tree utilization, proved to have no usefulness on fire hazard reduction. Uneven-aged cutting without any fuel management treatment showed substantial fire behavior potential, far beyond the control limit of direct attack methods. Residual duff depth was not significantly different between the burned and the unburned treatment units. Mineral soil exposure of the burned unit was significantly greater than the unburned unit in only one of the study stands. Removal of the litter fuels was significantly greater in the burned units, contributing to a receptive seedbed for natural regeneration of shade-intolerant tree species. Fire succeeded in eliminating Douglas fir regeneration. Losses of ponderosa pine seedlings were substantial, but a few saplings and seedlings did survive the fire. Fire also killed 6·5 to 9% of the overstory trees (over 3 m in height). Overstory mortality was statistically significant, but this mortality was confined to smaller trees (less than 12 cm in d.b.h.). Guidelines are offered for a safe and effective prescribed burning under standing timber in ponderosa pine stands.

The purpose of the study was to analyse height growth, mortality, and ingrowth of individual small-sized trees in uneven-aged spruce-dominated stands. It was based on experimental data from 16 stands for a 15-year observation period including four measurements with a 5-year interval. In the data of this study, the heights of small-sized trees varied from 0.1 to about 9 m. Results showed that the growth of small trees was rather slow, particularly in the smallest size classes. With average growth rates it would take about 60 years for a freshly emerged spruce germinant to achieve 1.3 m in height. The stand density, site quality and selection cuttings affected the growth of small-sized spruces. Average five-year mortality rates for spruce, birch and pine were 17.0%, 40.9% and 33.9%, respectively. Annual ingrowth rates with the threshold height of 1.3 m for the three species were on average 30.4, 2.8 and less than 0.1 trees per hectare, respectively. Even if, a selection cutting of modest intensity (25% of basal area removed on average) seemed to have accelerated the growth of small spruces, it is recommended that more intensive harvestings be applied to enhance the survival and growth of small spruces. It is also concluded that shade intolerant species like birch and pine do not seem to be capable of developing into viable undergrowth in spruce selection stands with their current levels of stand density.

In the late 1960s the Forests Department of Western Australia decided to change its logging strategy in the southern forest from light selection cutting to heavy selection cutting and clear-felling. This raised some concern about the effect on the water resources in the region. Four small catchments (Crowea, Poole, Iffley and Mooralup) were therefore selected in 1975 to study the effect of heavy selection cutting and clear-felling followed by regeneration on streamflow, stream salinity and groundwater levels. The catchments were logged between November 1976 and March 1978. Regeneration began within eighteen months after the completion of logging. During the study (1976–1985) the annual rainfall in the region was generally below the long-term mean. This probably influenced the magnitude and duration of the hydrologic response to logging and regeneration, but not the general trends. Groundwater levels rose for two–four years after logging and then started to fall again. They can be expected to reach the values they would have been at without logging within fifteen years after the beginning of regeneration. In the relatively dry Mooralup catchment, logging had little effect on the groundwater level. As a result of logging streamflow increased for two years (1977 and 1978) and then gradually declined again as the vegetation regenerated. Streamflow is also likely to be back to pre-logging values within fifteen years after the beginning of regeneration. In the Mooralup catchment, where streamflow volumes are naturally small, this may have happened after six years of regeneration. Flow-weighted mean annual stream salinities rose for one–three years after logging but have declined since. Even at their highest level they remained below the upper limit for high-quality drinking water. Stream salinites are likely to return to the level they would be at without logging at the same time as streamflow and groundwater levels.