Forest Harvesting Research Articles

Direct and Indirect Effects of Habitat Disturbances on Caribou Terrestrial Forage Lichens in Montane Forests of British Columbia

Cumulative effects of increased forest harvesting, mountain pine beetle (Dendroctonus ponderosae; MPB) outbreaks, and wildfire in low-elevation lodgepole pine (Pinus contorta) forests could limit long-term winter habitat supply for the northern group of southern mountain caribou (Rangifer tarandus). In a 17 year longitudinal study of vegetation remeasurements at eight sites in north-central and west-central British Columbia (BC), we assessed responses of terrestrial caribou forage lichen abundances to nine forest harvesting treatments and one prescribed burn 8–14 years following treatment, as well as to MPB attack. Overall, after initially declining following forest harvesting, mean forage lichen abundance increased between 1 and 2 years post-harvest and 13 and 14 years post-harvest at 10 of 11 site/treatment combinations. Mean forage lichen abundance decreased following MPB attack at all sites. Biophysical factors influencing rates of lichen recovery post-disturbance include site type (transitional vs. edaphic), a reduction in favourable conditions for moss recovery, level of MPB attack, and both seasonal timing and method of forest harvesting. When considering effects of forest harvesting on forage lichens, objectives of silvicultural management strategies should focus on protecting and retaining terrestrial lichens at edaphic sites and on re-establishing terrestrial lichens at transitional sites.

The DESC catchments: Long‐term monitoring of inland Precambrian shield catchment streamflow and water chemistry in Central Ontario, Canada

AbstractSince the early 1970s, the Dorset Environmental Science Centre (DESC) research catchments have been home to long‐term monitoring and study of terrestrial headwater catchment processes, their linkages to inland aquatic ecosystems and the influence of both natural variation and human activities. Located on the Precambrian Shield in central Ontario, Canada, covered by mixed Great Lakes‐St. Lawrence forest, the 29 catchments, defined by inflows and outflows to eight lakes, have been monitored for streamflow, meteorology and water chemistry, with long‐term datasets spanning from 1976 to the present. These datasets have provided insights into cold region hydrologic processes such as runoff generation, wetland and groundwater–surface water interactions, snow and ice processes, and catchment linkages to lake nutrient budgets and ecology. The datasets have supported catchment transit time estimates, hydrological modelling and cold region intercomparison studies. Starting with early research efforts driven by concerns over impacts from cottage development and acid deposition on soils, rivers and lakes, the DESC catchment datasets have supported study of impacts of stressors of forest harvesting, calcium depletion, road salt application and climate change. Ongoing monitoring of streamflow, meteorology and water chemistry in the DESC catchments continues to offer unique opportunities for investigation of critical zone processes in Precambrian shield catchments, their model representation and anthropogenic impacts.

Задержание атмосферных осадков пологом древостоя березово-елового молодняка в условиях средней тайги Республики Коми

The paper highlights 10-year-long study results on rainfall retention by the canopy of secondary birch-spruce young stand in the middle taiga subzone of the Komi Republic. The average rain retention by the canopy of a birch-spruce young forest in relation to an open area is determined. The studied young growth keeps less precipitation volumes than spruce forests and medium-aged deciduous stands of the middle taiga subzone. We have viewed a number of factors controlling precipitation retention. Spruce crowns keep 28 %, birch keeps 13 % of exposed place bulk precipitation. The largest precipitation volumes in the birch-spruce young growth fall through the inter-crown spaces — about 95 % of exposed place bulk precipitation. The rain retention by the canopy of the studied young forest is characterized by a high variability. We have assessed the seasonal and annual dynamics of rainfall retention. Within the seasonal dynamics, the periods from June to early August and from end September to October have a decrease and from August to September there is an increase in the retention value for the studied birch-spruce young growth. There exists a certain link between precipitation retention by the canopy of the studied young forest and exposed area bulk precipitation. This link is expressive for spruce crowns compared with birch crowns. The 10-year-old birch-spruce wood intercepts less rainfall than at the age of 20. However, the 10-year-long study period does not show any clear dynamics of retention increase. The data obtained can be used in forest hydrology to assess impacts of forest harvesting on water-regulating properties of taiga forests.

Untangling harvest‐streamflow responses in foothills conifer forests: Nexus of teleconnections, summer‐dominated precipitation, and storage

AbstractThis study re‐evaluated data from the historical Tri‐Creeks Experimental Watershed (1967–1988) in Alberta, Canada to address the initial question of forest harvest effects on streamflow and investigate the potential influence of teleconnections, summer‐dominated precipitation, and watershed storage on runoff generation. Tri‐Creeks has deep (up to 21 m) glacial deposits underlain by folded and faulted sedimentary bedrock with considerable potential for subsurface water storage. Timing of the conifer forest harvest experiment in two sub‐watersheds (>50% harvested) and one reference occurred near the 1976–77 Pacific Decadal Oscillation (PDO) phase change that led to less snowfall, but little difference in annual precipitation or runoff between phases after harvest. Established statistical and hydrological modelling methods that used regression techniques of observed and simulated streamflow to separately analyse sub‐watersheds did not detect change in average daily or annual runoff due to harvest. The interannual hydroclimatic variability influenced by the climate shift, attenuation of summer precipitation by the drier antecedent conditions in the warm period following harvest, and large potential for subsurface water storage contributed to shifts in runoff and uncertain detection of streamflow response. However, a hydrological modelling approach using calibrated parameters separately in the pre‐ and post‐harvest periods indicate significant change in rainfall‐generated peak runoff events and summer runoff following harvest, which was not detected in the reference watershed. Model calibration required less soil storage capacity in the treated watersheds in the post‐harvest period compared to the reference likely due to reduced transpiration that increased the likelihood of storm runoff during larger summer rainfall events. Within the context of streamflow responses to harvest in conifer dominated forest landscapes with seasonal snow cover, this study illustrates how complexity of climate variability and interaction with watershed storage and continental summer‐dominated precipitation may confound and mask the interpretation of harvest effects in paired‐watershed studies.

Macroinvertebrate responses to differing riparian treatments following forest harvest in the headwaters of Trask River watershed

Although it is well-established that macroinvertebrates are an integral part of a healthy stream ecosystem, studies designed to inform forest harvest best management practices for sustainability of macroinvertebrate communities in small streams have been limited. Current riparian management practices for headwater streams generally focus on providing adequate wood supply, reducing debris flows and transport of sediment, and maintaining water quality in larger streams that contain fish. Here we studied the effects of contemporary forest harvest practices on benthic macroinvertebrate density and community composition in 12 small headwater streams as part of the Trask River Watershed Study. To account for seasonal and year-to-year variability in macroinvertebrate densities, we sampled each site at the same time of year for six years before and four years after harvest. Three watersheds were clearcut with variable riparian buffers, three were clearcut with 12 m riparian buffers, and one was thinned with 15 m buffers. Five adjacent watersheds were not treated and were studied as reference sites. All sites had approximately 50 yr old conifer and alder forests, which had revegetated following fires and harvest in prior decades.In these steep mountain streams, benthic macroinvertebrate density and community composition were generally similar across watersheds prior to harvest. Collectors were the most abundant functional feeding group, followed by shredders; scrapers were the least abundant. After harvest, in two of the three clearcut watersheds with variable buffers, the total benthic density and percentage of collectors increased, primarily due to greater numbers of Chironomidae. We also observed more abundant emergence post-harvest at these two watersheds. In the third clearcut watershed with a variable buffer and in the three clearcut watersheds with uniform 12 m riparian buffers, we did not see changes in density or functional feeding groups after harvest. We explored the spatial and temporal aspects of the data using both non-parametric and parametric statistical methods. High variability swamped the treatment effect when watersheds were grouped by riparian treatment for the repeated measure analyses, while NMDS showed a significant shift post-harvest for the watersheds with variable buffers. In the clearcut watersheds with uniform buffers, macroinvertebrates densities and community composition did not shift. At two of the clearcut watersheds with variable buffers, we observed increased density for the first two years after harvest, and chironomids comprised up to 80% of the abundance in samples. In the subsequent years, we documented mixed responses for two watersheds. It was invaluable to have multiple pre- and post-harvest sampling periods in both harvested and reference watersheds in order to better identify site specific responses to treatment and to separate background variability from responses to harvest. We show that retention of riparian vegetation on headwater streams during clearcut harvesting minimized changes in total macroinvertebrate densities and community composition. Small buffers may be key to maintenance of diverse stream invertebrate communities in headwaters.

How resilient are the oak forests of Askot wildlife sanctuary, western Himalaya?

Monitoring resilience in Himalayan forest ecosystem requires an understanding of community structure, regeneration, and anthropogenic disturbances. Four classes of temperate broadleaf forest dominated by different species of oak viz., Banj oak (Quercus leucotrichophora), Rianj oak (Q. lanuginosa), Moru oak (Q. floribunda), and Kharsu oak (Q. semecarpifolia) were assessed between 1700-3000 m asl in Askot wildlife sanctuary, western Himalaya. A total of 300 quadrats of 10x10 m size were placed randomly in 30 forest sites at different altitudes using standard phytosociological methodologies. The tree density ranged from 503±33.8 to 694±75.9 indi. ha-1 with a basal area of 45.0±6.5 to 60.4±6.8 m2 ha-1. Across the forest communities, the sapling density was 590±54.9 to 755±63.4 indi. ha-1 and seedling density was 175±88.5 to 770±208.8 indi. ha-1. Principal component analysis was used to examine the impact of anthropogenic pressures on regeneration of different oak communities. The study reveals that despite the extractive pressures on oak forests in the study area, the regeneration of Q. leucotrichophora and Q. lanuginosa was fair. However, the regeneration of Q. semecarpifolia and Q. floribunda was poor which needs to be protected from livestock grazing. In addition to appropriate management inputs, sustainable forest harvesting practices must be implemented in the region.

Biodiversity conservation in private forests: Factors driving landowner's attitude

In many countries, biodiversity conservation strategies are aimed not only for state land, but also private land. Participation of landowners in conservation programmes can be viewed as a continuum from voluntary by the landowner to force by the existing legislation. The biodiversity conservation system of Latvia represents a case where in certain situations (such as establishment of micro-reserves) strict forest management restrictions can be implemented without acceptance of landowners. This causes conflicts with forest owners, which can negatively affect the success of reaching biodiversity conservation goals. Therefore, we aimed to explore factors driving private forest owner's attitude towards biodiversity conservation in their land. Mixed-mode survey was utilized for gathering information from 386 private forest owners. Ordinal logistic regression (OLS) models were used to analyze relationships between predictor and response variables. Our results suggested that financial dependence on income from forest harvest was the main factor causing negative attitude of landowners towards biodiversity conservation measures for private land of Latvia. This factor was significantly correlated with a forestry background (education, occupation and size of forest land). However, landowner education and general conservation values also influenced landowner willingness to accept conservation measures on private forest land. We highlighted a great potential for voluntary biodiversity conservation mechanisms in Latvia, which could complement existing (regulatory approach based) biodiversity conservation instruments.

Potential of Wood Harvesting Residues and Residual Stand Damage due to Timber Harvesting: A Case Study at PT Austral Byna in Central Kalimantan, Indonesia

The practice of timber harvesting in natural forests which has been conducted up to now still leaves wood harvesting residue and residual stand damage. Most condition of wood harvesting residue is still good and can be utilized. The objective of this research was to determine the potency of wood harvesting residue and residual stand damage on timber harvesting in natural forests. The data on wood utilization, wood harvesting residue, and residual damage were collected from three sample plots. The sample plots were arranged in a systematic and purposive manner, and the data were processed with tabulation and average analysis. Research results showed that the average volume of wood being utilized was 9.212 m3 tree−1. The average volume of wood harvesting residues was 2.310 m3 tree−1, and the total average volume of wood harvesting residues which were good, defected, and broken was 2.121 m3 (80.952%), with an average volume for good wood harvesting residue condition of 1.038 m3 (34.808%). Proportions of wood harvesting residues were 2.154 m3 (94.444%) consisting of buttress as large as 0.102 m3 (5.159%), stumps as large as 0.375 m3 tree−1 (23.597%), butt as large as 0.855 m3 (35.930%), and end part as large as 0.821 m3 (29.758%). The average number of trees with a diameter of 20 cm which were damaged due to felling and skidding was 5 trees ha−1 (5.40%) and 6 trees ha−1 (6.58%), respectively.

Soil Compaction after Increasing the Number of Wheeled Tractors Passes on Forest Soils in West Carpathians

Soil disturbance and compaction are inherent in ground-based harvesting operations. These changes are affected by numerous factors, related mainly to the technical parameters of the machines, soil conditions, and the technology used. This study aimed to analyze the changes of surface layers of soil caused by skidder traffic without loads on the Cambisols of Western Carpathians. We observed changes in the soil bulk density and penetration resistance. The results showed that only machine traffic caused a 0.32 to 0.35 (g cm−3) increase in soil bulk density. Besides machine traffic, bulk density was affected by soil moisture content. Penetration resistance of soil increased by 0.15 to 1.04 (MPa) after traffic of 40 machines. Penetration resistance showed a lower increase after traffic, and regression and correlation analysis proved a relationship between penetration resistance, skeleton content, and penetration depth, besides the number of machine passes (r = 0.33–0.55). Observing the changes in the physical properties of soils caused by machine traffic allows for a more detailed view of the effects of forest harvesting machinery on forest soils.

Multi-objective models for the forest harvest scheduling problem in a continuous-time framework

In this study we present several multi-objective models for forest harvest scheduling in forest with single-species, even-aged stands using a continuous formulation. We seek to maximize economic profitability and even-flow of timber harvest volume, both for the first rotation and for the regulated forest. For that, we design new metrics that allow working with continuous decision variables, namely, the harvest time of each stand. Unlike traditional combinatorial formulations, this avoids dividing the planning horizon into periods and simulating alternative management prescriptions before the optimization process. We propose to combine a scalarization technique (weighting method) with a gradient-type algorithm (L-BFGS-B) to obtain the Pareto frontier of the problem, which graphically shows the relationships (trade-offs) between objectives, and helps the decision makers to choose a suitable weighting for each objective. We compare this approach with the widely used in forestry multi-objective evolutionary algorithm NSGA-II. We analyze the model in a Eucalyptus globulus Labill. forest of Galicia (NW Spain). The continuous formulation proves robust in forests with different structures and provides better results than the traditional combinatorial approach. For problem solving, our proposal shows a clear advantage over the evolutionary algorithm in terms of computational time (efficiency), being of the order of 65 times faster for both continuous and discrete formulations.

Developing highly transparent yet ultraviolet blocking fully biocomposite films based on chitin and lignin using ethanol/water as processing solvents

Developing fully biobased products with functionality in a green fashion is highly desirable to meet the increasing demand for environmental sustainability and mitigate “white pollution” by petroleum-based counterparts. Here, chitin from shrimp shells was propionylated to obtain chitin propionate (CP) with significantly improved solubility in organic solvents, organosolv lignin (OSL) was extracted from the forest harvest residuals. The fully biobased composite consisting of CP as a matrix and OSL as a UV-blocker were successfully prepared using acidic ethanol/water as a green processing solvent. The results indicated that the 5% OSL addition enabled the CP film to block approximately 98% UV light while allowing 71% visible light transmittance; tensile and thermal properties were also retained. Nearly 100% UV light was blocked with 20% OSL addition, but visible light transmittance was moderately sacrificed. This study provides an alternative solution to produce novel fully biobased films with high transparency yet excellent UV protection for potential packaging applications.

Assessing the potential for unaccounted emissions from bioenergy and the implications for forests: The United States and global

AbstractDevelopment of the bioenergy sector is being actively pursued in many countries as a means to reduce climate change and fulfill international climate agreements such as the Paris Agreement. Although biomass for energy production (especially wood pellets) can replace carbon‐intensive fossil fuels, its net greenhouse gas impact varies, and the production of wood pellets can also lead to intensification in forest harvests and reduction of forest carbon stocks. Additionally, under specific conditions, emissions associated with imported biomass feedstocks may be omitted from national accounts, due to incompatibilities in accounting approaches. We assessed the risks and potential scale of emissions omitted from accounts (EOA) among key trading regions, focusing on the demand for wood pellets under different levels of climate mitigation targets. Our results suggest that the global production of wood pellets would grow from 38.9 to 120 Mton/year between 2019 and 2050 in a scenario that limits global mean temperature increase to 1.5°C above pre‐industrial levels. A large portion of this occurs in North America (36.8 Mton/year by 2050), Europe (47.6 Mton/year by 2050), and Asia (23.3 Mton/year by 2050). We estimate that in a 1.5°C scenario, global EOA associated with international trade of wood pellets has the potential to reach 23.81 MtCO2eq/year by 2030 and 69.52 MtCO2eq/year in 2050. Emissions resulting from European biomass energy production, based on wood pellet imports from the United States, may reach 11.68 MtCO2eq/year by 2030 and 33.57 MtCO2eq/year in 2050. The production of wood pellet feedstocks may also present a substantial carbon price arbitrage opportunity for bioenergy producers through a conjunction of two distinct GHG accounting rules. If this opportunity is realized, it could accelerate the growth of the bioenergy industry to levels that harm forests’ function as a carbon sink and omit actual emissions in national and global accounting frameworks.

Quantifying the Life Cycle Greenhouse Gas Emissions of a Mechanized Shelterwood Harvest Producing Both Sawtimber and Woodchips

Forests are used to mitigate anthropogenic greenhouse gas (GHG) emissions through carbon offset programs, and forest management is generally accepted as “carbon neutral”. However, forest harvesting operations depend heavily on fossil fuels, so it would be remiss to broadly paint all forms of management as carbon neutral without empirical verification of this claim. Biomass feedstock, as a means to supplant fossil fuel consumption, has received the bulk of investigative efforts, as the carbon benefit of biomass is one of the most contentious among wood products, because it does not create long-term carbon storage. A life cycle assessment (LCA) was conducted on a winter shelterwood harvest occurring in the Adirondacks of upstate New York. Primary data were collected daily throughout the operation and used to model the impact attributed to producing clean chips and logs for delivery to a pulp mill and sawmill, respectively. This harvest produced 4894 Mg of clean chips and 527 Mg of sawtimber. We calculated that 39.77 and 25.16 kg of carbon dioxide equivalent were emitted per Mg of clean chips and sawtimber, respectively, with a total observed flow of GHG into the atmosphere between 206 and 210 thousand kilograms. The results contribute to our understanding of the global warming potential of implementing a forest harvest to produce raw materials for medium- and long-term carbon storage products such as paper and dimensional hardwood lumber.

Can Food Crop Medicine Reduce Pressure on Forest Harvest in Nigeria?

Awareness created in the social media through smart phones had popularized the practice of using food crop parts such as leaves, fruits, roots and seeds to treat common illness which had hitherto been treated with herbs from the wild. This study investigated whether the use of food crops for medicine can reduce pressures of harvesting medicinal plants from the forest. A combination of three research methods: structured questionnaire survey; informal discussions with stakeholders in food crop medicines and observations on collection and preparation of food crop medicines were used to collect data. Simple random sampling method was used to select 62 respondents for questionnaire survey and discussion groups in Ota Ogun State, Nigeria. Data were presented in tables and percentages. A Chi-square analysis was used to test the research hypothesis. Results derived from data analyses indicated that food crop medicine (FCM) was: (i) widely used; (ii) fully accepted; (iii) gradually reducing pressures in natural forests; and (iv) used to compliment indigenous traditional medicine. A conclusion was reached that FCM had come to stay as a major primary health delivery. Moreover, FCM has found a place in herbal treatments of diseases.
 Keywords: Food crop medicine, Traditional medicine, Traditional plants, Natural forests, Herbs.

HAND-ARM VIBRATION IN DIFFERENT OPERATING CONDITIONS WITH A CHAINSAW

The mechanization of forest harvesting is a trend in Brazil. However, small and medium-sized companies in the forestry sector, even today, opt for semi-mechanized harvesting, using chainsaws for the harvesting and sectioning of trees. Despite technological advances, when operated continuously, chainsaws may cause damage to the operator’s body, acting as a stressor, and vibration excess is responsible for numerous health disorders, among them the Raynaud syndrome. In this sense, this study aimed to determine the vibration levels to which a chainsaw operator is subjected, during the transversal cut (tracing) of the wood, in different forest species and cutting sets. The treatments consisted of three forest species (Eucalyptus grandis, Eucalyptus dunnii and Acacia mearnsii De Wild) and two cutting sets, consisting of square tooth chains of the semi-chisel and chisel types. The vibration assessment was based on the criteria established by the Regulatory Standards NR15, NHO10 and ISO 2631-4. The results of vibration levels were higher than the reference limits established by ISO 2631-4, and, for both cutting sets, the highest vibration levels occurred on the “x” axis. After the data processing, the acceleration values resulting from the normalized exposure to hand-arm vibrations showed significant differences for the “y” and “z” axes. Therefore, it can be inferred that the chainsaw operation is a stressor, potentially capable of causing damage to workers' health.

GESTÃO DA EXTRAÇÃO FLORESTAL COM O INDICADOR EFICIÊNCIA GLOBAL DE MÁQUINAS FLORESTAIS (EGMF)

ABSTRACT Performance indicators are tools capable of exposing measurable characteristics and generating relevant information on forest operations, thus being considered pillars for managers to make agile and assertive decisions. Forest extraction with a forwarder must be improved, understanding the factors that affect the costs of this machine, such as productivity (PR), fuel consumption (FC), operational efficiency (OE), and quality of operation. Thus, the objective of this study was to evaluate the implementation of the Overall Efficiency of Forest Machines (OEFM) indicator in the management of forest extraction data using forwarders. Data were collected during forest harvesting from five operating fleets, in commercial eucalypt plantations, in full-tree and coppice regimes, in the states of Bahia and Espírito Santo. The indicator was expressed as a percentage calculated by OEFM = ( ( 4 ∗ PR ) + ( 3 ∗ FC ) + ( 3 ∗ OE ) ) / 10. The performance of the machines was evaluated by a stochastic model of dynamic simulation of systems in eight scenarios, proposing improvement for the average individual volume harvested, fuel consumption, and mechanical or operational stops. Analyzes were performed using PowerSim Studio 9 software. The OEFM of two fleets was higher than the established target of 95.17%, with 95.72% and 97.44%. The OEFM indicator proved to be useful in the management of forest extraction with adequate and easy-to-understand information from a large amount and variety of data. The stochastic simulation model was efficient to study the impact on the global efficiency and the flow of wood extraction by the forwarder.

Evaluating the productivity and costs of five energywood harvesting operations in the lower Mid-Atlantic region of the U.S

ABSTRACT Woody biomass is an important feedstock for renewable energy production in the United States. Residues are produced by forest harvests, and some operations utilize this material for energywood. Energywood requires additional processing and is often the lowest value product generated. Additional research quantifying the productivity and costs of energywood operations could allow stakeholders to evaluate the efficiency of those operations and identify areas for improvement. This study evaluated five energywood harvesting operations in the Lower Mid-Atlantic region of the United States (two Appalachian Mountain harvests and three Coastal Plain harvests). Each harvesting operation was observed for 4–7 days, and productivity data were collected on each harvesting function using time study and activity sampling methods. Productivity and costs of each operation were estimated, and equipment mixes and harvesting methods were evaluated to determine efficiency. Interviews were also conducted with each logging contractor to understand operating strategies and decision making. Cut and haul costs averaged (USD) $32.07/tonne and ranged from $26.19 to $38.28/tonne. Hauling consistently comprised the largest function cost at an average of $12.24/tonne. Machines handling energywood were less productive than those harvesting roundwood because of the large effect average stem size had on productivity levels. Harvesting system analysis also highlighted the importance of ensuring a balanced equipment mix to lower costs and ensure efficiency. This research provides stakeholders with a valuable comparison of energywood harvesting operations in the Lower Mid-Atlantic region of the United States that can be used to make better-informed decisions regarding the efficient and economical harvest of energywood.

Active Harvesting in the Non-national Headwater Conservation Forests (Academic Article)

Active Harvesting in the Non-national Headwater Conservation Forests (Academic Article)

Natural regeneration in logging gaps of different sizes in Subri River Forest Reserve (Ghana)

Subri River Forest Reserve (SR) is the most extensive forest area in Ghana with an accompanying rich floral species. Over the years, logging from both legally prescribed and illegal operations remain the predominant forest disturbance in SR. Gap creation following logging is crucial in determining tree species composition and diversity. Hence, the study evaluated the composition and diversity of naturally regenerated tree species in logging gaps of different sizes and, again examined the roles of these tree species in fulfilling the economic and ecological agenda of sustainable forest management after logging in SR. Twelve gaps were randomly selected: 4 each were grouped into small size (≤ 200 m2), medium size (201–300 m2), and large size (≥ 300 m2). Data were gathered from 1 m2 circular area at gap centres and repeatedly inside 1 m width strip along 20 m individual N-S-E-W transects. Species diversity differed significantly between gap sizes. Higher diversity indices were measured in large size gaps. Gap sizes shared similar species. There were significant differences among various height groupings of tree species across all three gap sizes. Pioneers preferred medium to large size gaps, while shade-tolerant tree species preferred small size gaps for their abundance. Vulnerable and Lower Risk Near Threatened tree species under Conservation Status and, Premium and Commercial tree species under Utilisation Status preferred small size gaps for their proliferation and conservation. Therefore, we recommend the single tree-based selective logging for ensuring creations of small to medium size (200–300 m2) gaps through adjustments to the logging permit process, revision of Allocation Quota Permit, strict adherence to the 40-year polycyclic selection system, along with more dedicated enforcement and monitoring. Changes along these protocols would tremendously facilitate natural regeneration of different suites of timber species resulting in the improvement of the overall biodiversity conservation associated with the forest, more sustainable forest harvests and more income to those who receive permits.

Лесоэкологические последствия ландшафтных пожаров в Забайкалье

Лесоэкологические последствия ландшафтных пожаров в Забайкалье