Search Results (18)

(1) Background: Understanding how forest management practices regulate hydrological cycles is critical for sustainable water resource management and addressing global water crises. However, the effects of light-felling (selective thinning) on hydrological processes in temperate mixed forests remain poorly understood. This study comprehensively evaluated the impacts of light-felling intensity levels on three hydrological layers (canopy, litter, and soil) in mid-rotation Korean pine (Pinus koraiensis) forests managed under the “planting conifer and preserving broadleaved trees” (PCPBT) system on Changbai Mountain, China. (2) Methods: Hydrological processes—including canopy interception, throughfall, stemflow, litter interception, soil water absorption, runoff, and evapotranspiration—were measured across five light-felling intensity levels (control, low, medium, heavy, and clear-cutting) during the growing season. The stand structure and precipitation characteristics were analyzed to elucidate the driving mechanisms. (3) Results: (1) Low and heavy light-felling significantly increased the canopy interception by 18.9%~57.0% (p < 0.05), while medium-intensity light-felling reduced it by 20.6%. The throughfall was significantly decreased 10.7% at low intensity but increased 5.3% at medium intensity. The stemflow rates declined by 15.8%~42.7% across all treatments. (2) The litter interception was reduced by 22.1% under heavy-intensity light-felling (p < 0.05). (3) The soil runoff rates decreased by 56.3%, 16.1%, and 6.5% under the low, heavy, and clear-cutting intensity levels, respectively, although increased by 27.1% under medium-intensity activity (p < 0.05). (4) The monthly hydrological dynamics shifted from bimodal (control) to unimodal patterns under most treatments. (5) The canopy processes were primarily driven by precipitation, while litter interception was influenced by throughfall and tree diversity. The soil processes correlated strongly with throughfall. (4) Conclusions: Low and heavy light-felling led to enhanced canopy interception and reduced soil runoff and mitigated flood risks, whereas medium-intensity light-felling supports water supply during droughts by increasing the throughfall and runoff. These findings provide critical insights for balancing carbon sequestration and hydrological regulation in forest management. Full article

Research Highlights: We report a 45-year time-line of forest restoration after harvesting and responses of red-backed voles (Myodes gapperi), an indicator species of closed-canopy forests. Background and Objectives: We have a unique long-term window to test four hypotheses that evaluated the relationship of M. gapperi with old forest structural attributes. Materials and Methods: The study began in old-growth lodgepole pine (Pinus contorta var. latifolia) through clearcutting, regeneration, stand thinning, fertilization, and growth to mature forest (1979 to 2024) in southern BC, Canada. Populations of red-backed voles were monitored in all phases of forest restoration. Results: Clearcutting resulted in the extirpation of M. gapperi followed by small (≤2 voles/ha) populations in young (13–23 years) thinned and fertilized stands. At age 33, the mean annual abundance of M. gapperi (6.5 to 8.7/ha) was highest in the heavily thinned and old-growth stands. At age 43, mean numbers of M. gapperi ranged from 2.7 to 4.2/ha in these same stands. Heavily thinned stands had large trees, multi-layered canopies of conifers, and understory patchiness. Conclusions: This is the first report of long-term responses of M. gapperi to the restoration of mature forest. M. gapperi is a suitable species for monitoring the recovery of some old forest structural features. Full article

Research highlights: At the turn of the 21st century, there were more forest territories found disturbed by both natural processes (climate change, wildfires, insect outbreaks, permafrost thawing, etc.) and anthropogenic interferences (air pollution, clearcuts, etc.). Seed collecting, then growing seedlings in forest nurseries, and then planting seedlings over lost forest areas are the forestry measures needed to restore the forest after disturbances. Goals were to construct bioclimatic models of ranges and seed mass of major Siberian conifers (Siberian pine (Pinus sibirica Du Tour), Siberian fir (Abies sibirica Ledeb.), Siberian spruce (Picea obovata Ledeb.), Siberian larches (Larix sibirica Ledeb., L. gmelini (Rupr) Rupr, and L. cajanderi Mayr.) and Pinus sylvestris L.) and predict their potential change in a warming climate by the mid-century. Methods: Multi-year seed mass data were derived from the literature, seed station data, and were collected in the field. Climate data (January and July data and annual precipitation) were derived from published Russian reference books and websites on climate. Bioclimatic indices (growing degree-days > 5 C, negative degree-days < 0 C, and annual moisture index) were calculated from January and July temperatures and annual precipitation for both contemporary and the 2050s (2040–2060) climates using the general circulation model INM-CM5-0 and two climate change scenarios, ssp126 and ssp585, from CMIP6. Our bioclimatic range models (envelope and MaxEnt models) and regression seed mass models for major conifers were built based on these bioclimatic indices. Additionally, their ranges were limited by the permafrost border, which divided the forest area into the permafrost-free zone, where five conifers are able to grow, and the permafrost zone, where only one conifer, Dahurian larch, is able to survive. Results: Under warmed climates, the ranges of all Siberian conifers would expand 1.5-fold due to the decrease in the permafrost zone, except Dahurian larch, which would lose 5–20% of its coverage due to permafrost retreat. Conifers shifting northward would be slower than predicted only by warmed climates because permafrost would thaw slower than climates would warm. Scots pine may expand by up to 60%, covering dryer lands in the south. Future climates were found to favor seed mass increase for major Siberian conifers and for heavier seed to shift northward. Our major conifers differ by the type of seed dispersal mode: zoochoric, animal (Siberian pine) and anemochoric, and wind-dispersed (other five trees). The seed masses of the five anemochoric conifers varied within the range of 1.5–15 g of 1000 seeds, which is about 40–50-fold less than that of zoochoric Siberian pine. Site climate explained about 28–65% of the seed mass variation for the five anemochoric trees and only 11% for Siberian pine (zoochoric tree). This finding needs additional research to explain the reasons. Conclusions: Warmed climates would favor the expansion of the ranges of major Siberian conifers and their seed mass to be heavier, which would support the high-quality seed production for forest well-being and its restoration in Siberia. Full article

The silver fir (Abies alba Mill.) is among the most valuable conifers in Europe for ecological and economic reasons. Throughout the course of history, primarily in the 20th century, its share in stands has been declining due to ill-suited management practices, especially clear-cut management, air pollution (SO₂ and NO_X emissions), and wildlife-induced damage. This literature review compiles findings from 338 scientific papers. It describes futures for silver fir and its distribution, ecological requirements, threats and diseases, seed production and nurseries, and forest management practices with emphasis on ongoing climate change. Based on recent knowledge of fir ecology and population dynamics, small-scale shelterwood and selection management have been introduced in fir stands, which have also stabilized them. Fir is an essential species for maintaining high stability and biodiversity, especially on planosols and in waterlogged habitats. Owing to its shade tolerance and environmental plasticity, it can coexist very well with many tree species in mixtures, which can increase the productive potential of stands within the natural range in Europe. The average stand volume of mature fir stands ranges from 237–657 m³ ha⁻¹. For its successful natural regeneration, it is essential to reduce cloven-hoofed game and thus prevent bud browsing damage. The attractiveness of fir in terms of heavy browsing is the highest of all conifers (52% damage). On the other hand, fir is a species relatively resistant to bark stripping and the spread of secondary rot compared with Norway spruce (Picea abies [L.] Karst.). Under global climate change, fir is expected to shift to higher elevations with sufficient precipitation, while in the southern part of its natural range or at lower elevations, outside water-influenced habitats, it is likely to decline. Climate change is intricately linked to the heightened prevalence of forest pathogens with significant damage potential in Europe, necessitating careful consideration and strategic adaptation within management practices of fir forests. Full article

Clearcutting has tended to simplify forest structure and species composition, with potential negative consequences for biodiversity. Retention forestry emerged as an alternative to minimize this concern in intensively managed forests. In central Mexico, this approach was first implemented a decade ago in temperate forests, but an examination of its effects on floristic diversity and composition is non-existent. We evaluated and compared richness, diversity, and floristic composition among harvested, retention, and conserved areas in a conifer-dominated forest of central Mexico, with various parametric and non-parametric analyses. Species’ ecological and structural importance was also evaluated. We recorded 138 species, 95 genera, and 44 families of plants. Harvested areas listed the most species (99) with herb dominance, tree homogeneity, and the highest number of exotics. Retention and conserved areas’ floristic composition was similar, with the presence of epiphytes and terrestrial orchids, considered indicators of conservation. The retention areas recorded rare and endangered species, tree heterogeneity, and juveniles of structural species of temperate forests. Conserved areas showed a greater number of structural mature elements and exclusive species, though there was a smaller species number (75). We demonstrated that retention forestry is achieving its goal by maintaining the structural elements, habitats, and plant diversity of the temperate forests analyzed. Full article

The recent technological development of batteries has allowed the production of powerful tools that are also used in forestry operations. For this reason, this study aimed to compare the performance of two latest chainsaw models in a conifer clear-cut. The examined chainsaws, the battery-powered Stihl MSA 300 and the petrol-powered MS 261 C-M, have comparable power and weight. The overall working times were recorded and then gross, net and felling/processing productivities were quantified. Our findings reported that in a working day (7.4 h gross time), each chainsaw felled and processed an average of 20 trees of 0.64 m³ with an average diameter at breast height of 28 cm. Considering the net productivity, no statistically significant differences were recorded between the two chainsaws. Investigating the productivities on operations conducted using the chainsaws, the battery chainsaw showed a lower average tree-processing productivity than that recorded for the petrol chainsaw. On average, the battery duration was 0.88 h, while the petrol tank duration was 0.97 h. Our study shows that battery chainsaws have great potential in forestry operations; however, considering the actual need for 8 charges per standard workday, optimizing battery management is an important objective for future work. Full article

Treatment of conifer stumps with a control agent effectively prevents Heterobasidion spore infections in summer cuttings and protects the residual stand and the next tree generation from damage caused by Heterobasidion root rot. Thus far, stump treatment experiments have been carried out in mineral soils, and no information is available on the efficacy of stump treatment agents in boreal peatland conditions. In the present study, biological and chemical control agents (Phlebiopsis gigantea and urea, respectively) were tested in Scots pine and Norway spruce stands subjected to thinning, cap cutting, and clearcutting on drained peatland in Central Finland. The control efficacy of urea was high in both spruce and pine stumps (on average 99.5 and 85.3%, respectively), while the efficacy of P. gigantea was highly variable on both tree species and ranged from full protection down to negative control effect, i.e., there were more Heterobasidion infections on the treated than untreated half of the stumps. The moisture content of the stump wood or the thickness of the peat layer did not affect the control efficacy of either control agent. These results emphasize a need for further studies to determine the reasons for the unsteadiness of the biological control in peatland conditions. Full article

Retention forestry is a harvesting system that intentionally retains important forest structures at harvest time. We examined the effect of dispersed retention on the productivity and cost of harvesting operations in a large-scale field experiment in conifer plantations in Hokkaido, Japan. For dispersed retention, we retained broad-leaved trees in three levels (10, 50, or 100 trees/ha). We used daily operator reports and investigated time consumption (h/m³) of felling and pre-hauling operations and the total cost to roadside. Compared with clearcutting, mean felling time was 7% and 17% longer, and mean pre-hauling time was 20% and 19% longer in 50 and 100 retained trees/ha, respectively. The other operations were not affected by tree retention because they were conducted at pre-existed strip roads or landings where no trees were retained. Increased time consumption caused an increased cost of felling and pre-hauling. Compared with clearcutting, the combined cost of felling and pre-hauling was 14% and 18% higher in 50 and 100 retained trees/ha, respectively. However, the total cost to roadside increased only by 3% compared with clearcutting because these two operations in total occupied 19% of the overall cost, and the cost of the other operations was not affected by tree retention. This suggests that the impact of tree retention on the total cost was small and that the harvesting system used in the present study can reduce cost increment due to tree retention unless trees are not retained on strip roads. Full article

Gymnosperms are generally regarded as poor resprouters, especially when compared to angiosperms and particularly following major disturbance. However, is it this clear-cut? This review investigates two main aspects of gymnosperm resprouting: (i) various papers have provided exceptions to the above generalization—how frequent are these exceptions and are there any taxonomic trends?; and (ii) assuming gymnosperms are poor resprouters are there any anatomical or physiological reasons why this is the case? Five of six non-coniferous gymnosperm genera and 24 of 80 conifer genera had at least one species with a well-developed resprouting capability. This was a wider range than would be expected from the usual observation ‘gymnosperms are poor resprouters’. All conifer families had at least three resprouting genera, except the monospecific Sciadopityaceae. Apart from the aboveground stem, buds were also recorded arising from more specialised structures (e.g., lignotubers, tubers, burls and underground stems). In some larger genera it appeared that only a relatively small proportion of species were resprouters and often only when young. The poor resprouting performance of mature plants may stem from a high proportion of apparently ‘blank’ leaf axils. Axillary meristems have been recorded in a wide range of conifer species, but they often did not form an apical dome, leaf primordia or vascular connections. Buds or meristems that did form often abscised at an early stage. While this review has confirmed that conifers do not resprout to the same degree as angiosperms, it was found that a wide diversity of gymnosperm genera can recover vegetatively after substantial disturbance. Further structural studies are needed, especially of: (i) apparently blank leaf axils and the initial development of axillary meristems; (ii) specialised regeneration structures; and (iii) why high variability can occur in the resprouting capacity within species of a single genus and within genera of the same family. Full article

Coarse woody debris on the forest floor contributes to maintenance of forest biodiversity and long-term ecosystem productivity. Down wood is often dispersed over harvested sites during logging activities, thereby leaving piles of postharvest debris as “excess” material at landings and roadsides. These wood residues may be burned in most jurisdictions in North America to reduce a perceived fire hazard. The fire hazard debate needs to acknowledge the documented benefits of woody debris retention while striking a balance among biodiversity, bioenergy, and alternative uses for debris, while reducing ignitions by humans. The burning of excess woody debris also creates smoke, causes the release of greenhouse gas (GHG) emissions, and creates human health issues, particularly for vulnerable individuals. The relationship of wildfire smoke to human health problems is well documented. However, there is no scientific evidence showing that postharvest debris piles are ignition points for forest fires, other than those caused by humans. Wood residues from forest harvesting or natural disturbance wood from wildfire and insect outbreaks may be used as renewable biomass “feedstocks” that could help improve energy supplies and reduce GHG emissions. If not marketable, the management of postharvest debris should seek alternative outlets that do not dispose of debris by burning, but still meet fire hazard abatement requirements. The construction of woody debris structures (e.g., piles and windrows) built at the time of forest harvesting and log processing, or later at the site preparation stages, has positive benefits for wildlife habitat and forest biodiversity. A windrow or series of piles may connect patches and reserves of mature forest and riparian areas on clearcut openings. Piles and windrows have consistently provided habitat on new clearcuts for southern red-backed voles (Myodes gapperi) and Microtus voles, as well as a host of other forest-floor small mammal species, at least up to 12 years postconstruction. Woody debris provides important habitat for foraging and cover attributes for marten (Martes americana), weasels (Mustela spp.), and other furbearers. A list of “What to do?” and “When and Where?” with options for construction of woody debris habitats: poorest, good, better, and best are given. In the cases where fire risk from humans is minimized and there are no marketable wood products, eight alternative management scenarios for postharvest woody debris are provided. These include: (1) piles for wildlife habitat; (2) distribution of debris in partial cut forests; (3) machinery to break up and crush debris; (4) protection of riparian zones with barriers for cattle; (5) construction of range fencing; (6) reclamation of landings and skid-trails; (7) soil fertility and reduction in weed competition and drought for planted conifers; and (8) slope stabilization and revegetation. Advantages and disadvantages (if known) are given for each alternative. A flow chart for the fate of excess postharvest woody debris with respect to fire hazard abatement and markets or nonmarkets is given. Full article

Relatively minimal attention has been given to the hydrology of natural broadleaf forests compared to conifer plantations in Japan. We investigated the impacts of ground litter removal and forest clearing on surface runoff using the paired runoff plot approach. Plot A (7.4 m²) was maintained as a control while plot B (8.1 m²) was manipulated. Surface runoff was measured by a tipping-bucket recorder, and rainfall by a tipping-bucket rain gauge. From May 2016 to July 2019, 20, 54, and 42 runoff events were recorded in the no-treatment (NT), litter removed before clearcutting (LRBC), and after clearcutting (AC) phases, respectively. Surface runoff increased 4× when moving from the NT to LRBC phase, and 4.4× when moving from the LRBC to AC phase. Antecedent precipitation index (API₁₁) had a significant influence on surface runoff in the LRBC phase but not in the NT and AC phases. Surface runoff in the AC phase was high regardless of API₁₁. The rainfall required for initiating surface runoff is 38% and 56% less when moving from the NT to LRBC, and LRBC to AC phases, respectively. Ground litter and canopy function to reduce surface runoff in regenerated broadleaf forests. Full article

Forest soil biodiversity, which drives natural ecosystem multifunctionality, can be altered by incorrect forestry management practices. Pinus laricio is the most representative and widespread conifer species in Calabria, South Italy, and appropriate management is needed to maintain Pinus laricio forest for its great economic and natural value. In Europe, thinning is considered the most effective silvicultural treatment to maintain/increase the ecological value of coniferous stands. In this study, moderate thinning (MT), intense thinning (HT), and clear cut (CC) treatments were used to manage Pinus laricio stands with the aim of identifying the thinning intensity that is less detrimental to soil biodiversity. The effects of the different thinning intensities were evaluated, in two contrasting seasons (summer and winter), on the abundance, and diversity of arthropods, fungi, and bacteria colonies as well as on selected soil properties (organic matter, humification index, bulk density, pH) related to soil habitability. Results evidenced that the abundance, species richness, and diversity of arthropods, as well as fungi, bacteria colonies, and soil properties, changed with the treatments and seasons. Under HT, the greatest biodiversity and the highest amounts of arthropods, fungi, and bacteria were found in both seasons. This study finds evidence for Connell’s intermediate disturbance hypothesis, highlighting that the greatest organic carbon content and humification index, as well as the lowest bulk density, found in HT reduced the likelihood of competitive exclusion between occurring species, thereby promoting high species richness and diversity. This study gives insights into ecological relationships between understory composition related to tree species abundance and soil community. Full article

The production of tree seedlings in forest nurseries and their use in the replanting of clear-cut forest sites is a common practice in the temperate and boreal forests of Europe. Although conifers dominate on replanted sites, in recent years, deciduous tree species have received more attention due to their often-higher resilience to abiotic and biotic stress factors. The aim of the present study was to assess the belowground fungal communities of bare-root cultivated seedlings of Alnus glutinosa, Betula pendula, Pinus sylvestris, Picea abies and Quercus robur in order to gain a better understanding of the associated fungi and oomycetes, and their potential effects on the seedling performance in forest nurseries and after outplanting. The study sites were at the seven largest bare-root forest nurseries in Lithuania. The sampling included the roots and adjacent soil of 2–3 year old healthy-looking seedlings. Following the isolation of the DNA from the individual root and soil samples, these were amplified using ITS rRNA as a marker, and subjected to high-throughput PacBio sequencing. The results showed the presence of 161,302 high-quality sequences, representing 2003 fungal and oomycete taxa. The most common fungi were Malassezia restricta (6.7% of all of the high-quality sequences), Wilcoxina mikolae (5.0%), Pustularia sp. 3993_4 (4.6%), and Fusarium oxysporum (3.5%). The most common oomycetes were Pythium ultimum var. ultimum (0.6%), Pythium heterothallicum (0.3%), Pythium spiculum (0.3%), and Pythium sylvaticum (0.2%). The coniferous tree species (P. abies and P. sylvestris) generally showed a higher richness of fungal taxa and a rather distinct fungal community composition compared to the deciduous tree species (A. glutinosa, B. pendula, and Q. robur). The results demonstrated that the seedling roots and the rhizosphere soil in forest nurseries support a high richness of fungal taxa. The seedling roots were primarily inhabited by saprotrophic and mycorrhizal fungi, while fungal pathogens and oomycetes were less abundant, showing that the cultivation practices used in forest nurseries secured both the production of high-quality planting stock and disease control. Full article

The consequences of anthropogenic climate change are one of the major concerns of conservation biology. A cascade of negative effects is expected to affect various ecosystems, one of which is Central European coniferous forests and their unique biota. These coniferous forests are the primary habitat of many forest specialist species such as red wood ants. Climate change-induced rising of temperature allows trees to skip winter hibernation, making them more vulnerable to storms that cause wind felling, and in turn, promotes bark beetle infestations that results in unscheduled clear-cuttings. Red wood ants can also be exposed to such habitat changes. We investigated the effects of bark beetle-induced clear-cutting and the absence of coniferous trees on colonies of Formica polyctena, including a mixed-coniferous forest as a reference. Our aim was to investigate how these habitat features affect the nest characteristics and nesting habits of F. polyctena. Our results indicate that, in the absence of conifers, F. polyctena tend to use different alternatives for nest material, colony structure, and food sources. However, the vitality of F. polyctena colonies significantly decreased (smaller nest mound volumes). Our study highlights the ecological flexibility of this forest specialist and its potential to survive under extreme conditions. Full article

Over the last three decades, the ecological basis for the generalized use of even-aged silviculture in boreal forests has been increasingly challenged. In boreal mixed-wood landscapes, the diminishing proportion of conifers, to the benefit of intolerant hardwoods, has been a primary concern, coupled with the general rarefication of old-growth conifer-dominated stands. In this context, partial cutting, extended rotations and forest renewal techniques that eliminate or reduce regenerating hardwoods have been proposed as means of regaining greater conifer cover. As a result, experimentation and industrial application of various forms of both variable retention and partial harvesting are occurring across the commercial Canadian boreal forest. In this study, we compared the effects of two harvesting intensities, clearcutting and low-intensity partial cutting (removal of 25–31% of tree basal area), on hardwood and conifer regeneration levels 7–19 years following treatments in aspen (Populus tremuloides)-dominated stands and verified whether regeneration differences existed between micro-sites on and off machinery trails. The abundance of aspen regeneration increased with percent basal area removal and was positively correlated to the abundance of mature aspen prior to harvesting. The abundance of fir (Abies balsamea) regeneration after partial cutting was similar to controls and higher than after clear-cutting and was positively correlated with ground cover of mixed litter (i.e., mixture of needles and leaves) and negatively correlated with ground cover of broadleaf litter. These results suggest that it is possible in boreal mixed-woods to control aspen abundance and promote or maintain conifer regeneration through silvicultural treatments that limit canopy opening and promote mixed forest floor litter. Full article