Clear-cutting Research Articles

Effects of the litter leaching process by throughfall after clear cutting of primary Pinus koraiensis forest

Effects of the litter leaching process by throughfall after clear cutting of primary Pinus koraiensis forest

Large differences in plant nitrogen supply in German and Swedish forests – Implications for management

In European forests, plant N supply varies from regions where N deposition is negligible and a low natural N supply limits production to regions where high N deposition adds to a high natural N supply. Here, we ask if the differences in N supply are too large to make one system of management for wood production, continuous–cover forestry or rotational forestry, optimal across these conditions.We analyzed the C/N ratio in c. 8400 samples of surficial soil layers along a 2400 km long transect through Sweden and Germany to obtain a quantitative description of differences in plant N supply. We discuss the differences in relation to forest management, especially evidence that soil C/N ratios below 25 are associated with higher N supply, risks of leaching of nitrate, and gaseous losses of N2O, whereas ratios above 25 are associated with a tighter N cycle and an N limitation to tree growth.The percent soil with C/N ratios above 25 declines from 91 in N. Norrland in Sweden to 26 in Germany. Simultaneously, mor soils (with a distinct organic layer on top of the mineral soil) decline from 95% to 16%, while mull soils (in which organic matter and mineral particles are mixed) increase from 1% to 40%. However, low C/N ratios also occur in the north, where we find the largest width in C/N ratios from 16 in mull soils to 36 in mor soils, which compares with a variation in Germany from 17 to 27. Soils under conifers generally have higher C/N ratios than soils under broadleaves, but our survey data cannot support that the trees are the sole cause of this pattern. Very low C/N ratios occur in conifer–dominated forests in the north.The high incidence (74%) of C/N ratios below 25 indicates that forest management in Germany should use methods, which minimize the risk of N losses. Continuous–cover forestry may fulfill that objective. In the north with 9% of the soils below this threshold, risks of N losses are small. There, rotational forestry involving clear–felling alleviates the competition for soil N from larger trees allowing successful regeneration of tree seedlings. From the perspective of interactions between plant N supply and management of forests for wood production, no single management system seems optimal along this large gradient. We propose that research on forest management systems should address the importance of N supply.

Fertilization and clear-cutting effects on greenhouse gas emissions of pinewood nematode damaged Masson pine plantation

ABSTRACT Introduction: Management practices are essential for maintaining forest ecological functions under increasing diseases and pest disasters. The effects of nitrogen fertilization (NF) and clear-cutting (CC) on the soil microbial community structure and greenhouse gases emission were investigated of pinewood nematodes (Bursaphelenchus xylophilus)-infected Masson pine (Pinus massoniana) plantations. Outcomes: CC increased the soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) contents relative to the control (CK). NF increased the SMBN but had no significant effect on the SMBC content. The total fungal and bacterial abundances increased in the CC treatment compared with the CK, but there was no significant difference between the NF and CK. The cumulative soil CO2 emission (2.35 t C·hm−2) was higher than that of CK (1.65 t C·hm−2) in summer, and the cumulative annual N2O emission (16.90 kg N·hm−2 yr−1) of NF was approximately 47 times of CK (0.36 t N·hm−2·yr−1). CC increased the CO2 flux (2.21 t C·hm−2) in summer but have no significantly effects on N2O emission. Conclusion: These results indicated that NF and CC practices changed forest soil microbial community structure and affected soil greenhouse gas emissions in pinewood nematodes -infected Masson pine plantations. The CO2 emission rates increased in the NF and CC treatments, which reduced the carbon sequestration function of forests and had a negative impact on climate change.

Combined Non-parametric and Parametric Classification Method Depending on Normality of PDF of Training Samples

Classification method with combined nonparametric and parametric classifications which depends on the normality of Probability Density Function of training samples is proposed. The proposed classification method is also based on spatial information for high spatial resolution of satellite based optical sensor images is proposed. Also, a classification method which takes into account not only spectral but also spatial features for LANDSAT-4 and 5 Thematic Mapper (TM) data is proposed. Treatment of the spatial-spectral variability existing within a region is more important for such high spatial resolution of satellite imagery data. Standard deviations in small cells, such as 2x2, 3x3 and 4x4 pixels, were used as measures to represent the spatial-spectral variabilities. This information can be used together with conventional spectral features in a unified way, for the traditional classifier such as the pixelwise Maximum Likelihood Decision Rule (MLHDR). The classification performance of new clear cuts and alpine meadows which are very close in spectral space characteristics and difficult to distinguish them by conventional methods are focused. Through experiments, it is found that there is a substantial improvement in overall classification accuracy for TM forestry data. The Probability of Correct Classification (PCC) for the new clear cuts and the alpine meadows classes rose by 7% to 97% correct. The confusion between alpine meadows and new clear cuts was reduced from 9% to 3%.

Mapping of a science and technology policy network based on social network analysis

PURPOSE: The main purpose of this paper is to define a science and technology policy network in the form of a social network, from the perspective of policy documents, and then analyze it using the social networks analysis (SNA) method. METHODOLOGY: As a case study, the science and technology policymaking network in Iran is analyzed using the suggested framework in this research. The data used in this study were collected through the content analysis of 25 policy documents and an interview with 20 Iranian science and technology policy elites, before being interpreted using the social network analysis method and software such as NetDraw and UCINet. FINDINGS: The most pivotal science and technology policymaking institutions in Iran and the interactions between them were determined from the network viewpoint. This was achieved by performing a two-dimensional core-periphery analysis, identifying the cut points and blocks, and measuring the structural power of each institution using the degree centrality, closeness centrality, and betweenness centrality methods. IMPLICATIONS FOR THEORY AND PRACTICE: The most important practical implications of this research are: the integration of a number of policymaking institutions, the division of clear and precise work between policy institutions, the design of vertical and horizontal coordination mechanisms between institutions, the elimination of interferences of some institutions in the tasks of the others, the design of complementary mechanisms to control the role of cutting points, and paying attention to the important activities in the margins of the network. ORIGINALITY AND VALUE: The most important contribution of this research is to develop a framework for studying science and technology policy and then to develop a method for studying science and technology policy based on SNA. Therefore, the framework for studying science and technology policy in a cycle consists of three stages: 1- Agenda setting and prioritization (at two levels of mega policies and meta policies); 2- Design and implementation or executive policies (in three parts: demand-side policies, supply-side policies, and networking and interconnection infrastructure policies); 3- evaluation and policy learning.

Evaluation of different strategic planning approaches in a forest plantation in the North of Misiones Province, Argentina.

In this paper we evaluate different models and constraints to define strategic planning approaches. In addition, we analyze the best models to meet the expectations generated by the organization. A forest company situated in the province of Misiones, Argentina, provided the data. Hence, forest growth was simulated and, ultimately, optimized planning was used to evaluate different scenarios with 50-year horizon. The best results to stabilize log production were obtained when the harvest is relaxed in ±2 years. Relaxing the clear-cut age leads to a better balance in planting, thinning (1, 2, 3 and 4) and clear felling operations. We found that when maximizing the economic benefit, the NPV is slightly higher, however, this is not significant. In this sense, the planner chooses an economic or volumetric objective function. Furthermore, we demonstrated that model 1 presented better results than model 2 because it manages to stabilize production in the planning horizon. The results allow forest companies to see the implication of choosing the model for strategic planning.

Low soil disturbance during boreal forest well site development enhances vegetation recovery after 10 years

Boreal forests are increasingly exposed to industrial well site development. Little information exists on the optimal construction and reclamation strategies needed for vegetation recovery, including methods of well site preparation, soil storage, woody debris management, and revegetation. In this study we examined intermediate-term (10 yr) recovery of vegetation on 33 well sites distributed across NE Alberta, Canada, constructed and reclaimed using different site preparation methods, including high (HD), intermediate (ID), and low intensity (LD) disturbance of surface soils. Comparisons also included soil piling methods on HD sites, debris management on ID and LD sites, and tree planting on all sites. Comparisons were made to adjacent uncut forest to assess similarity, and at a subset of locations to harvested clear cuts. Ten years into recovery, vegetation was most similar between uncut forest and well sites developed using LD construction methods in species richness, diversity, and cover of vegetation growth forms and ground cover components (bare soil, litter, moss and lichen). Well sites using HD and ID had vegetation more dissimilar to uncut forest. Clear cuts harvested at the same time as the well sites also differed in composition from the forested controls, but remained more similar to the LD well sites than the HD and ID well sites. Effects of reforestation (tree planting), the technique of soil piling, and different forms of woody debris management (spreading vs windrowing) had little impact on vegetation recovery. Overall results highlight the importance of using LD well site preparation techniques where possible to keep mineral soil and embedded plant propagules intact to maximize boreal forest recovery following disturbance.

Efectos del manejo forestal en las propiedades físicas e hidrológicas de un Umbrisol en la Sierra Madre Occidental

Introduction: Land uses associated with anthropogenic activities affect soil quality negatively.Objective: To determine the effect of regeneration cuts on the physical and hydrological properties of an Umbrisol.Materials and methods: In each stand (Seed trees [ST], clear cutting [CC], selection [S], regenerated area post fire [PF] and reference [R]), in situ tests were performed and four samples composed of soil by depth (0 to 20 cm and 20 to 40 cm) were collected. Data were analyzed by Kruskal-Wallis and ANOVA tests. The physical variables (bulk density [BD], porosity, silt, leaf litter and humus, mechanical resistance to penetration [MRP], sand and clay) and hydrological variables (infiltration, field capacity, permanent wilt point, available water and permeability) were related by means of the Spearman correlation coefficient.Results and discussion:Differences were significant (P ≤ 0.01) in MRP, sand and clay in the forest stand factor. For the depth factor, all the variables were similar, except for the MRP; its increase in clear cutting was higher than 100 %, with respect to R. The interaction was only significant (P ≤ 0.01) for the sand percentage. The Kruskal-Wallis test (P ≤ 0.05) indicated that infiltration, humus and litter were lower in clear cutting. There is a significant negative correlation (P ≤ 0.01) of BD with permeability, porosity, clay and sand. ST and clear cuttings increased BD (24.28 and 37.58 %) and MRP (32.59 and 222.22 %), with respect to R.Conclusion: ST and selection cuts did not cause significant variations in properties such as those of a total cut (clear cutting).

Ten years on – a decade of intensive biodiversity research after the 2009 Black Saturday wildfires in Victoria’s Mountain Ash forest

ABSTRACT The catastrophic 2009 wildfires in the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria provided an opportunity to gain new insights into the responses to fire by various elements of the biota. Ongoing long-term monitoring at a large number of permanent field sites for up to 25 years prior to the fire, together with 10 years of post-fire monitoring, has provided an unparalleled series of datasets on mammal, bird, and plant responses on burned and unburned sites. The empirical studies briefly summarized in this paper show patterns of steep declines in large old trees and declines in site occupancy by arboreal marsupials and birds. These changes contrast markedly with the responses of the two most common species of small mammals (the Agile Antechinus [Antechinus agilis] and Bush Rat [Rattus fuscipes]), which recovered within two generations after the fire. Declines in arboreal marsupials, birds and large old trees have also occurred on unburned sites, indicating an ecosystem-wide trend. In general, logging had a greater impact than fire on the majority of groups of birds and plants, particularly post-fire salvage logging that occurred in some areas following the 2009 wildfires. Beyond interactions between fire and post-fire (salvage) logging and their effects on forest biota, we have uncovered evidence of other kinds of interactions in Mountain Ash forests. These include interactions between: (1) the severity of fires and logging history, (2) post-fire bird population recovery and long-term climate and short-term weather conditions, and (3) impacts on forest soils. The structure and landscape composition of the Mountain Ash ecosystem has been radically altered over the last century. This has resulted from the combined impact of several large fires, including the 2009 fires as well as widespread clearfell logging that has been conducted within state forests over the last 50 years. The ecosystem now supports old growth cover that is 1/30th to 1/60th of what it was estimated to have been prior to European settlement. The ongoing decline of key components of the Mountain Ash ecosystem has led to it being classified as Critically Endangered and at high risk of ecosystem collapse. We argue that current forest policy and practices need to better mitigate the effects of fire on this already highly disturbed forest and enhance the possible persistence of species in this ecosystem. Several key strategies are required to do this. First, there is a need to significantly expand the extent of old growth within the Mountain Ash forest estate. This is because fire severity is diminished in such areas. Spatial contagion across old-growth dominated landscapes also may be suppressed relative to landscapes composed primarily of young forest. Allied management strategies include the protection of more mesic parts of Mountain Ash landscapes as these are less likely to burn or at least burn at high severity. Such enhanced protection should include an expanded network of buffers around drainage lines and waterways as these are where fire severity is likely to be lowest and also where old growth elements like large old hollow-bearing trees are more abundant. In addition, all existing living and dead hollow-bearing trees need to be protected by buffers of unlogged forest within wood production forests to promote their standing life and better conserve cavity-dependent fauna such as the Critically Endangered Leadbeater’s Possum (Gymnobelideus leadbeateri) and other declining taxa like the Greater Glider (Petauroides volans).

P.186 Molecular pathways underlying schizophrenia

Temperature and humidity conditions affect the growth and success of ectotherm insects. Red wood ants of the Formica rufa group are able to regulate the temperature of their nests to be close to the optimum, typically higher than ambient in northern latitudes and higher elevation. The mound-shaped nests are constructed from organic particles (needles, sticks, etc., plant material) and from soil particles. Nest mounds typically have a relatively dry inner structure but moister surface layer which may help the ants to insulate nests against cooling winds. Forest clear felling exposes nest mounds to direct sunlight, drier microclimate and increased wind. We studied whether clear felling affects the nest surface moisture and temperature conditions. We found that i) nest surfaces were significantly drier in clear fells than in forests, ii) a high height/diameter ratio and an increase in the nest volume increases surface dryness in clear fells but not in forests, iii) the nest temperatures relative to ambient temperature was higher in forests than in clear fells, and iv) the relative temperature increased with increasing moisture content of nest surface layer. The drying nest material and more unstable inside temperature may have adverse effects not only on the red wood ants themselves, but also for nest-dwelling soil organisms and myrmecophiles that live in red wood ant nests. In addition, changes in moisture and temperature could have effects on the rate of decomposition and nutrient turnover.

Diversity of Collembola under various types of anthropogenic load on ecosystems of European part of Russia.

BackgroundDespite the key role played by soil organisms in the functioning of terrestrial ecosystems and provisioning of ecosystem services (Barrios 2007, Bardgett and Putten 2014), available open data on soil biodiversity are incongruously scarce (Eisenhauer 2017, Cameron 2018). This is especially true for Russia, but contrasts long traditions of soil zoological research and large volumes of data that were collected during the second half of the 20th century for the territory of the former USSR. Last year, 41,928 georeferenced occurrences of soil-dwelling arthropods Collembola were digitised and published through GBIF.org. This work continues these activities. The article combines descriptions of three new sampling-event datasets about the various types of anthropogenic load on the diversity and the abundance of Collembola, small arthropods involved in the destruction of organic residues in the soil:Collembola of winter wheat fields in the Kaluga Region: conservation treatment versus conventional one (Kuznetsova et al. 2020). The following variants were studied: 1) treatment with organic fertilisers and tillage, without mineral fertilisers and pesticides, 2) the same, but without tillage, only discing; 3) with mineral fertilisers, pesticides and tillage. Special multi-scale sampling design was used. The material was collected on 24-26 July 2019 in Kaluga Region, European part of Russia. Data on 2226 records on 7302 specimens of 32 species in six fields in 486 soil cores are presented.Collembola of broadleaved forests along gradient of urbanisation in Moscow (Kuznetsova and Ageeva 2020). Sampling plots were placed in oak and lime forests located at different distances from the centre of Moscow. The material was collected in different seasons of 1990–1991. Data on 1737 records on 6873 specimens of 64 species (17 series of sampling, 720 soil cores) are presented.Collembola in clear cutting areas of Arkhangelsk Region: spatial and temporal series of the data (Kuznetsova and Klyueva 2020). Sampling plots were in birch forests of different ages with spruce underbrush and in old spruce forest. The study was carried out in July of 1970–1971 and 1984 in Arkhangelsk Region, European part of Russia. In 1970, cores were taken at sites where the forest was restored 15, 30 and 80 years after clear cuttings, as well as in a 180-year-old spruce forest. In 1984, sampling was repeated in two plots. Data on 1468 records on 18788 specimens of 47 species (seven series of sampling, 720 soil cores) are presented.New informationThese datasets contribute to filling gaps in the global biodiversity distribution of the Collembola. All datasets present new information about effects of agricultural treatments, urbanisation and clear cutting on springtail diversity and abundance in ecosystems of the European part of Russia.

Mapping thins to identify active forest management in southern pine plantations using Landsat time series stacks

The southeastern United States is unique in terms of both the intensity and scale of forest management, which includes substantial thinning and other forms of harvesting. Because thinning is not a land use transition, and the disturbance signal is relatively subtle compared to a clear cut, there is a dearth of studies that attempt to detect thinning over large areas. Our goal was to detect pine thins as an indicator of active forest management using Landsat data. Areas which undergo thinning are indicative of active forest management in the region.Our approach uses a machine learning method which combines first-order harmonics and metrics from 3-year Fourier regression of Landsat time series stacks, layers from the Global Forest Change product, and other vetted national products into a random forests model to classify forest thins in the southeastern US. Forest Harvest Inspection Records for Virginia were used for training and validation. Models were successful separating thins from clear cuts and non-harvested pines (overall accuracy 86%, clear cut accuracy 90%, thin accuracy 83% for a simplified 10-predictor variable model).Examination of variable importance illustrates the physical meaning behind the models. The curve fit statistics (R2 or RMSE) of the NDVI, Pan, and SWIR1 harmonic curve fits, which are an indication of a departure from typical vegetation phenology caused by thinning or other disturbances, were consistently among the top predictors. The harmonic regression constant, sine and cosine from the Landsat 8 panchromatic band were also important. These describe the visible reflectance (500–680 nm) phenology over the time period at a high spatial resolution (15 m). The Loss Year from the Global Forest Change product, which is an indication of stand replacing disturbance, was also consistently among the most important variables in the classifiers.High performance computing, such as Google Earth Engine, and analysis-ready data are important for this approach. This work has importance for quantification of actively managed forests in a region of the world where production forestry is the dominant land disturbance signal and a significant economic engine.

Strength-limiting damage and its mitigation in CAD-CAM zirconia-reinforced lithium-silicate ceramics machined in a fully crystallized state

ObjectivesThe objective was to explore how clinically relevant machining process and heat treatment influence damage accumulation and strength degradation in lithium silicate-based glass ceramics machined in the fully crystallized state. MethodsA commercial zirconia-reinforced lithium silicate (ZLS) glass ceramic with a fully developed microstructure (Celtra® Duo) was studied. Disk-shaped specimens (nominal 10 mm diameter and 1 mm thickness) were fabricated either using a CAD-CAM process, creating a clinically relevant dental restoration surface, or were sectioned from water-jet cut cylindrical blocks with their critical surfaces consistently polished. Bi-axial flexure strength (BFS) was determined in a ball-on-ring configuration, and fractographic analysis was performed on failed specimens. XRD, AFM and SEM measurements were conducted before and after heat treatment. For each sample group, BFS was correlated with surface roughness. A two-way ANOVA and post-hoc Tukey tests were used to determine differences in BFS between machining and heat treatment groups (ɑ = 0.05). ResultsA two-way ANOVA demonstrated that BFS was influenced by fabrication route (p < 0.01) with CAD-CAM specimens exhibiting significantly lower mean BFS. A factorial interaction was observed between heat treatment and machining route (p < 0.01), where a significant strengthening effect of post-manufacture heat treatment was noted for CAD-CAM specimens but not sectioned and polished samples. CAD-CAM specimens exhibited sub-surface lateral cracks alongside radial cracks near fracture origin which were not observed for polished specimens. BFS did not correlate with surface roughness for polished specimens, and no change in microstructure was detectable by XRD following heat treatment. SignificanceThe mechanical properties of the ZLS ceramic material studied were highly sensitive to the initial surface defect integral associated with manufacturing route and order of operations. CAD-CAM manufacturing procedures result in significant strength-limiting damage which is likely to influence restoration performance; however, this can be partially mitigated by post-machining heat treatment.

Sediment export and impacts associated with river delta channelization compound estuary vulnerability to sea-level rise, Skagit River Delta, Washington, USA

Improved understanding of the budget and retention of sediment in river deltas is becoming increasingly important to mitigate and plan for impacts expected with sea level rise. In this study, analyses of historical bathymetric change, sediment core stratigraphy, and modeling are used to evaluate the sediment budget and environmental response of the largest river delta in the U.S. Pacific Northwest to western land-use change beginning in ~1850. An estimated 142±28 M m3 of sediment accumulated offshore of the emergent Skagit River delta in Washington State between 1890 and 2014 and ~68% of which was found in sand deposits. The fraction of sediment retained in sand reservoirs represents 83% of the expected fluvial sand delivery over this time suggesting their potential utility to evaluate the relative contribution of different land uses to sediment runoff through time. A significantly higher ratio of sand retention to delivery during the period 1890–1939 coincided with extensive watershed denudation (clear-cut logging) and channel dredging, relative to the period 1940–2014, which was characterized by improved forest practices and sediment management to protect endangered species but also more extensive river channelization. Retention in the delta foreset of 78% of the sand delivered by the river between 1890 and 1939 was associated with extensive sediment bypassing and delta progradation that is shown to be 5–10x higher than rates over the Holocene. Comparable offshore sand retention over time and higher nearshore retention subsequent to 1940 after normalizing for the assumed reduction in sediment runoff with improved forest practices, suggests that channelization has continued to influence sediment export at a magnitude equivalent to the effects of early logging. Adverse impacts of the bypassing sediment regime to natural hazards risk and ecosystem management concerns are discussed, including the role of the lost sediment as a resource to mitigate subsiding coastal lands vulnerable to flood impacts. The sediment budget and coastal change analyses provide a framework for evaluating opportunities to achieve greater resilience across several sectors of coastal land use important in low-lying deltas worldwide.

Evaluating the accuracy of ALS-based removal estimates against actual logging data

Key messageWe examined the accuracy of the stand attribute data based on airborne laser scanning (ALS) provided by the Finnish Forest Centre. The precision of forest inventory data was compared for the first time with operative logging data measured by the harvester.ContextAirborne laser scanning (ALS) is increasingly used together with models to predict the stand attributes of boreal forests. The information is updated by growth models. Information produced by remote sensing, model prediction, and growth simulation needs field verification. The data collected by harvesters on logging sites provide a means to evaluate and verify the accuracy of the ALS-based data.AimsThis study investigated the accuracy of ALS-based forest inventory data provided by the Finnish Forest Centre at the stand level, using harvester data as the reference. Special interest was on timber assortment volumes where the quality reductions of sawlog are model predictions in ALS-based data and true realized reductions in the logging data.MethodsWe examined the accuracy of total volume and timber assortment volumes by comparing ALS-based data and operative logging data measured by a harvester. This was done both for clear cuttings and thinning sites. Accuracy of the identification of the dominant tree species of the stand was examined using the Kappa coefficient.ResultsIn clear-felling sites, the total harvest removals based on ALS and model prediction had a RMSE% of 26.0%. In thinning, the corresponding difference in the total harvested removal was 42.4%. Compared to logged volume, ALS-based prediction overestimated sawlog removals in clear cuttings and underestimated pulpwood removals.ConclusionThe study provided valuable information on the accuracy of ALS-based stand attribute data. Our results showed that ALS-based data need better methods to predict the technical quality of harvested trees, to avoid systematic overestimates of sawlog volume. We also found that the ALS-based estimates do not accurately predict the volume of trees removed in actual thinnings.

Carbon benefits from Forest Transitions promoting biomass expansions and thickening.

The growth of the global terrestrial sink of carbon dioxide has puzzled scientists for decades. We propose that the role of land management practices—from intensive forestry to allowing passive afforestation of abandoned lands—have played a major role in the growth of the terrestrial carbon sink in the decades since the mid twentieth century. The Forest Transition, a historic transition from shrinking to expanding forests, and from sparser to denser forests, has seen an increase of biomass and carbon across large regions of the globe. We propose that the contribution of Forest Transitions to the terrestrial carbon sink has been underestimated. Because forest growth is slow and incremental, changes in the carbon density in forest biomass and soils often elude detection. Measurement technologies that rely on changes in two‐dimensional ground cover can miss changes in forest density. In contrast, changes from abrupt and total losses of biomass in land clearing, forest fires and clear cuts are easy to measure. Land management improves over time providing important present contributions and future potential to climate change mitigation. Appreciating the contributions of Forest Transitions to the sequestering of atmospheric carbon will enable its potential to aid in climate change mitigation.

Back to Roots: The Role of Ectomycorrhizal Fungi in Boreal and Temperate Forest Restoration

Temperate and boreal forests are increasingly suffering from anthropic degradation. Ectomycorrhizal fungi (EMF) are symbionts with most temperate and boreal forest trees, providing their hosts with soil nutrients and water in exchange for plant carbon. This group of fungi is involved in woody plants’ survival and growth and helps plants tolerate harsh environmental conditions. Here, we describe the current understanding of how EMF can benefit temperate and boreal forest restoration projects. We review current evidence on promising restoration plans that actively use EMF in sites contaminated with heavy metals, affected by soil erosion, and degraded due to clearcut logging and wildfire. We discuss the potential role of this group of fungi for restoring sites invaded by non-native plant species. Additionally, we explore limitations, knowledge gaps, and possible undesired outcomes of the use of EMF in forest restoration, and we suggest how to further incorporate this fungal group into forest management. We conclude that considering EMF – host interactions could improve the chances of success of future restoration programs in boreal and temperate forests.

Windthrow in streamside key habitats: Effects of buffer strip width and selective logging

Streamside forests are preserved from clear-cut logging in production forests and protected with uncut buffer strips in many countries. However, buffer strips often remain narrow due to economic reasons and, therefore, provide weak protection against adverse edge effects of clear-cuts and are vulnerable to windthrow. Selective logging of buffer strips is sometimes allowed to reduce their costs, but the decreased tree density may expose the buffer to higher occurrence of windthrow. We used a replicated two-factor experiment to assess the effects of buffer width (15 m or 30 m) and selective logging (0% or 30% of the basal area removed) on the risk of windthrow in boreal streamside forests in Finland. We examined the windthrown trees 12 years after experimental logging at 29 sites and at seven unlogged control sites. In addition, we studied the influence of topography and the extent of clear-cut logging in the surrounding forests on windthrow risk. The proportion of windthrown spruces at sites with 15 m buffer strips was, on the average, six times higher than at control sites and 2.5 times higher than at sites with 30 m buffer strips. In contrast, the proportion of windthrown spruces did not differ between sites with 30 m buffer strips and control sites. Selective logging did not increase the risk of windthrow strongly. However, sites with selectively logged 30 m buffers were slightly more prone to windthrow than control sites. The proportion of windthrown trees tended to increase with the extent of the adjacent clear-cut areas on both sides of the stream. We conclude that a 15 m buffer strip is not wide enough to protect streamside forests from substantial windthrow, while a 30 m buffer strip is sufficient in most cases. Selective logging of 30 m buffers may be undertaken at sites that are not under a high risk of windthrow. If selective logging enables a wider buffer strip, it may be a better option for protecting the streamside habitat from substantial windthrow than leaving a narrow buffer strip. Moreover, clear-cut harvesting on both sides of the stream should be avoided if the aim is to prevent excessive windthrow.

Changes in soil fungal community composition depend on functional group and forest disturbance type.

Disturbances have altered community dynamics in boreal forests with unknown consequences for belowground ecological processes. Soil fungi are particularly sensitive to such disturbances; however, the individual response of fungal guilds to different disturbance types is poorly understood. Here, we profiled soil fungal communities in lodgepole pine forests following a bark beetle outbreak, wildfire, clear-cut logging, and salvage-logging. Using Illumina MiSeq to sequence ITS1 and SSU rDNA, we characterized communities of ectomycorrhizal, arbuscular mycorrhizal, saprotrophic, and pathogenic fungi in sites representing each disturbance type paired with intact forests. We also quantified soil fungal biomass by measuring ergosterol. Abiotic disturbances changed the community composition of ectomycorrhizal fungi and shifted the dominance from ectomycorrhizal to saprotrophic fungi compared to intact forests. The disruption of the soil organic layer with disturbances correlated with the decline of ectomycorrhizal and the increase of arbuscular mycorrhizal fungi. Wildfire changed the community composition of pathogenic fungi but did not affect their proportion and diversity. Fungal biomass declined with disturbances that disrupted the forest floor. Our results suggest that the disruption of the forest floor with disturbances, and the changes in C and nutrient dynamics it may promote, structure the fungal community with implications for fungal biomass-C.

Типологічна структура соснових насаджень Центрального Полісся

У лісовому фонді державних лісогосподарських підприємств Житомирської області, які є характерними для Центрального Полісся, соснові насадження становлять від 31,5 до 87,7 % від площі вкритих лісовою рослинністю земель. Переважають свіжі та вологі субори й сугруди. Частка чистих соснових насаджень становить у середньому 23,9 % від площі вкритих лісовою рослинністю земель і 37,3 % від площі соснових насаджень, а потенційно можлива для створення чистих соснових насаджень – 7,7 і 11,2 % відповідно. Здійснені розрахунки є підставою для підвищення стійкості соснових насаджень регіону шляхом збільшення площі мішаних насаджень на ділянках із придатними для цього лісорослинними умовами. Водночас слід брати до уваги можливість зміни гігротопів унаслідок зміни клімату останніх років.