Forestry Operations Research Articles

Trophic level and edge history modulate the depth of edge influence

Habitat edges are increasingly important worldwide because of forest fragmentation and the loss of natural habitats. Reduction in habitat area, increased isolation of fragments are considered to be the primary cause of species decline and extinction in fragmented landscapes. Edge effect is a key determinant, since most effects of fragmentation attributed to patch area may be scaled-up edge effect. Moreover, the isolation of patches is basically determined by the filter function (permeability) of edges. The distance that edge effects extend into the adjacent core (interior) habitat (the depth of edge influence, DEI) is a central issue in edge studies, as it fundamentally influences environmental properties, composition and structure of core habitats, all which significantly control species occurrences. Most previous studies on DEI neglected the impact of origin and the processes maintaining edges, although the structural and functional properties of edges determined by their history may modulate the permeability of edges, and consequently DEI. Evaluating available information on ground beetles (Coleoptera: Carabidae) in forest edges, we show that both species traits and edge history affect DEI on ground beetles. We found that DEI on abundance of herbivore, omnivore and predator ground beetle species is similar in natural edges, and edges maintained by agriculture, while it is generally penetrated over greater distances into the forests across edges repeatedly disturbed by forestry or other anthropogenic interventions than across edges maintained by natural processes. We found extreme edge effect across edges under forestry activities, as DEI on abundance of predator species is penetrated into the forest interiors up to ≤ 300 m. According to our findings DEI is more pronounced for predators and across edges created and maintained by forestry operations, suggesting outstanding sensitivity of higher trophic level organisms to fragmentation caused by forestry activities. Our result suggests that in planning the optimal size and shape of fragments for ecosystem-based forest management, to provide a core zone, a minimum area of 50 ha of circular forest fragments is required for maintaining an intact ground beetle assemblage.

Problems of Legal Competency of Innovative Infrastructure Subject within the Format of Assistance to Entrepreneurship in Forestry Legal Relations: Expediency of European Union Experience Implementation

At present there is observed a change in world economy and development of evolving market relations in society alongside the transition of economy to innovative mode of development. Innovation infrastructure subjects act as obligatory participants of innovative relationships. According to the Law of Ukraine “On Investment Activity”, art.5, the subjects of innovative activities are physical and (or) juridical persons of Ukraine, physical and (or) juridical persons of foreign states, persons without citizenship, associations of the mentioned persons who conduct innovative activities in Ukraine and (or) involve property and intellectual values, invest their own or borrowed finances for realizing innovative projects in Ukraine[1]. Entrepreneurship is considered a leading component in the processes of stable development of forest resources under conditions of market liberalization of utilizing natural resources and forest in the EU. Attracting investments to this sphere is to be based on recognition of all kinds of forestry operations as business activities with corresponding remuneration of these activities’ results. Besides, improvement of financial mechanism is an integral condition of ecologically balanced use of forestry, because at present it acts as an impeding factor of efficient development of forestry into the EU countries. Investment provision improvement is possible under favorable credit and financial preconditions for financing the processes of restoring forest resources potential. It is possible to improve investment attractiveness of forestry business, especially for foreign investors, on the premise of real implementation of elements of modern ecological management into business practices. Keywords: EU countries, foreign experience, entrepreneurship, forests, forestry legal relations, innovations, innovative activities, innovative infrastructure, subjects.[1] Law of Ukraine “On investment activities”. The Verkhovna Rada Bulletin, 2002, no 36, p. 266.

Impact of Shortened Winter Road Access on Costs of Forest Operations

A significant portion of the forest harvesting in the cooler regions of North America occurs in the winter when the ground is frozen and can support machine traffic. Climate change may influence the cost of forestry operations by reducing the period of winter access in those cold regions. In this study, we examined the impact of a shortened period of frozen ground conditions on logging operation and costs. To adapt to shorter period of frozen soil conditions, logging contractors might need to provide more machines and labor to complete logging in a shorter period of frozen conditions. The objectives were to calculate the costs of logging operations of a hypothetical forestry company in Alberta, Canada under two conditions: first, when the wood was hauled to the mill directly; and second, when part of the wood was hauled to satellite yards close to the logging area, thereby minimizing the annual number of idle hauling trucks. General Circulation Models were used to predict future winter weather conditions. Using the current type of harvesting machines and hauling directly to the mill, the unit cost of logging operations ($/m3) was projected to increase by an average of 1.6% to 2.5% in 2030s, 2.8% to 5.3% in the 2050s and 4.8% to 10.9% in the 2080s compared to the base year of 2015–2016. With use of satellite yards during the winter logging, the total logging cost will increase over direct haul, by 1.8% to 2.8% in the 2030s, 3.1% to 5.7% in the 2050s and 5.2% to 11.4% in the 2080s. Using satellite yards, however, will provide year-around employment for hauling truckers and more consistent and reliable hauling operations.

Tarifs et tables de cubage d’arbres individuels du pin d’Alep, Pinus halepensis Mill., dans l’Aurès algérien

L’objectif de ce travail est d’élaborer des tarifs de cubage d’arbres individuels de pin d’Alep, Pinus halepensis Mill., de la pinède des Ouled-Yaâgoub en Algérie. Neuf fonctions linéaires et non linéaires ont été ajustées systématiquement sur des données collectées à partir de 340 arbres, représentatifs des différentes classes de diamètre et de hauteur, choisis parmi les arbres abattus dans le cadre des coupes d’exploitation finales dans les chantiers installés dans la zone étudiée. L’approche adoptée pour l’estimation des paramètres des différentes fonctions testées est basée sur la régression, linéaire et non linéaire, selon la technique des moindres carrés ordinaires pondérés. Des analyses numériques et graphiques basées essentiellement sur la distribution des résidus et la précision des tarifs obtenus ont été employées pour comparer les différentes fonctions étudiées. Deux fonctions ont été retenues pour le cubage d’arbres individuels dans la pinède du massif des Ouled-Yaâgoub en Algérie. La première à une entrée exprime le volume en fonction du diamètre de l’arbre à 1,30 m de hauteur, et la seconde à deux entrées exprime le volume en fonction du diamètre à 1,30 m de hauteur et de la hauteur totale. Les coefficients de détermination ajustés et les carrés moyens résiduels obtenus par ces deux fonctions ou tarifs sont respectivement 0,944 et 109,78 dm3 pour la première et 0,977 et 69,69 dm3 pour la seconde. Enfin, pour une gestion efficace du massif des Ouled-Yaâgoub, l’estimation du volume sur pied des arbres de pin d’Alep doit tenir compte de l’objectif souhaité. Le tarif à une entrée, plus rapide à matérialiser, peut être utilisé pour des interventions sylvicoles telles que les éclaircies alors que le tarif de cubage à deux entrées, qui est plus précis, peut être choisi pour des coupes finales dont le bois sera destiné à la vente où des précisions plus importantes sur les volumes produits sont nécessaires.

Еколого-економічна оцінка ефективності використання енергетичної деревини в регіональній агломерації «Дрогобиччина»

Агломерація є територіальним об'єднанням різних населених пунктів, пов’язаних економічними, трудовими, соціальними й іншими зв'язками. Однією із найважливіших сфер, в якій потрібно налагодити тісну співпрацю в межах агломерації, є підвищення енергоефективності. Особливістю регіональної агломерації «Дрогобиччина» є її приналежність до Карпатського економічного району, який характеризується найвищою в Україні лісистістю і де місцеве населення традиційно використовує деревину в енергетичних цілях для обігріву приміщень і приготування їжі. Відповідно тут є достатня кількість ресурсів деревної біомаси, яку можна і потрібно використовувати в енергетичних цілях, а також сприйняття цього виду палива як природного і прийнятного.
 Карпатський регіон має значний потенціал деревної біомаси, доступної для енергетичного використання шляхом залучення лісової деревини, деревини від проведення ландшафтних робіт, залишків деревини від технічної обробки, деревних відходів. Додатковими джерелами деревного палива можуть бути парки, полезахисні лісосмуги, енергетичні плантації, лісонасадження уздовж автомобільних доріг і залізниць, а також сухостій.
 Ресурсний потенціал енергетичної деревини на території регіональної агломерації «Дрогобиччина» формують ресурси спеціалізованих підприємств, де головними постачальниками деревної біомаси є ДП «Дрогобицьке лісове господарство», Дрогобицьке ДЛГП «Галсільліс» і потенційно КП «Зелений світ» у м. Борислав. У 2017 р. приріст деревини у лісовому фонді аналізованих підприємств становив: у ДП «Дрогобицьке ЛГ» – 113,4; Дрогобицькому ДЛГП «Галсільліс» – 32,2, КП «Зелений світ» – 0,9 тис. м3.
 Резервом підвищення ефективності використання деревини є порубкові рештки, об’єм яких на зрубах ДП «Дрогобицьке ЛГ» у 2017 р. становив 7,1 тис. м3, а на Дрогобицькому ДЛГП “Галсільліс” за перше півріччя 2018 р. – 0,5 тис. м3. Додатковим ресурсом деревної біомаси для використання в енергетичних цілях можуть слугувати відходи операційної діяльності лісових господарств. Ще одним способом отримання деревної біомаси є вирощування енергетичних плантацій.
 Для встановлення міри готовності місцевого населення використовувати деревину для опалення домогосподарств, а також чинників, які впливають на масштаби використання енергетичної деревини, було проведено соціологічне опитування населення м. Борислав. З’ясовано, що більшість жителів користуються індивідуальною системою опалення, використовуючи газ або комбіновані котли для опалення. Встановлено, що 40 % респондентів хотіли б змінити систему опалення. За сприятливих умов, таких як постійна наявність ресурсів, дешеві кредити на заміну системи опалення, субсидії на тверде паливо та активне просування деревної біомаси як джерела енергії, частина громадян висловила готовність перейти на опалювання житла енергетичною деревиною.

Positioning of coordinates and precision analysis of sample trees using the intelligent forest survey calculator

Sample trees have great significance for extracting forest parameters and realizing well-targeted forestry operations. Accordingly, determining the precise position and coordinates of the sample trees is of special importance. In this paper, a new type of portable electronic instrument with high precision, the Intelligent Forest Survey Calculator (IFSC), is introduced. For the instrument, we have developed guidelines and explained the principles and methods for surveying locations of sample trees in fixed plots during forest survey. The instrument was set up at a starting site near the center of a fixed sample plot, and different sites were observed according to the distribution and density of sample trees. The instrument can also determine the coordinates of the sample trees using an integrated angle and distance measurement device on the basis of Bluetooth Low Energy (BLE) data transfer. The measurement precision influenced by both the stability of the instrument and environmental changes within the investigated area. To verify and analyze the interior and exterior adherence accuracy of the 3D coordinates produced by the IFSC, we conducted experments on 20 × 20 m fixed plots in Beijing Songshan National Nature Reserve. The errors of planar positioning (X and Y directions) were 0.0572 and 0.0561 m respectively, and the error of height (Z direction) was 0.0643 m. Our data therefore demonstrate that the IFSC has high precision in measuring the position coordinates of the sample trees, and can provide accurate data that can meet the requirements of practical forest surveys.

The effect of forestry management activities on stream water quality within a headwater plantation Pinus radiata forest

Many long-term forestry water quality studies focus on the impact of the harvesting phase of forestry operations. As a result, the water quality impacts of other activities such as forest (re)planting, thinning and fertilising are less well understood. Here we report the results from 23 years of monthly water quality monitoring from a steep headwater catchment within the Waikato region, New Zealand. Three experimental sub-catchments were planted in different proportions of Pinus radiata (PW2 = 100%, K-Pine 57%; PW3 = 36%). PW2 and PW3 were historical pastoral sites in the first rotation of plantation forestry and K-Pine was harvested and subsequently planted in a second rotation of forestry. All sites underwent two phases of stand thinning six and eight years after planting. The most significant effect of forestry was the increase in nitrate-N (NO3-N) and total nitrogen (TN) concentrations in response to both stand planting and stand thinning operations. Planting resulted in significant increases in NO3-N, TN and DRP over a four-year planting period at PW2. Significant increases in NO3-N and TN were detected over a four-year thinning period, at all three experimental sites. We propose that stream NO3-N and TN concentrations increased in response to stand planting at PW2 because of the change in physical conditions (e.g. increased stream shading, proliferation of nitrogen fixing weeds and decreased spatial extent of seepage wetlands) caused by the change in land use. Increasing nitrogen concentrations due to decreasing stream runoff could also be contributing a factor. Any decrease in NO3-N and TN concentrations in response to increased uptake by the rapidly growing P. radiata appears to have been masked by these other factors. However, the increase in NO3-N and TN concentrations in response to stand thinning at all three experimental sites suggests that NO3-N uptake by growing trees is an important process. Over the entire forestry period, median NO3-N concentrations at PW2 (first rotation site) increased by a factor four (400–1590 µg l−1). The median NO3-N during the post-thinning period was also one order of magnitude higher than those measured at K-Pine (second rotation site) during the post-thinning period. We attribute these differences to the NO3-N legacy within soil and/or groundwater of the previous sheep and beef cattle grazing land use. Long-term use of the PW2 catchment for forestry may eventually reduce NO3-N concentrations to the lower levels measured at K-Pine. Therefore, while NO3-N concentrations and loads may increase in response to the establishment of plantation forestry we envisage that these will decline if plantation forestry continues beyond the first rotation. This research highlights: (i) the complex nature of the response of stream water quality to catchment land use changes, and (ii) the value of studies that monitor the impact of land use/cover change over the long-term.

PLANNING HARVESTING OPERATIONS IN FOREST ENVIRONMENT: REMOTE SENSING FOR DECISION SUPPORT

Abstract. The goal of this work is to assess a method for supporting decisions regarding identification of most suitable areas for two types of harvesting approaches in forestry: skyline vs. forwarder. The innovative aspect consists in simulating the choices done during the planning in forestry operations. To do so, remote sensing data from an aerial laser scanner were used to create a digital terrain model (DTM) of ground surface under vegetation cover. Features extracted from the DTM are used as input for several machine learning predictors. Features are slope, distance from nearest roadside, relative height from nearest roadside and roughness index. Training and validation is done using areas defined by experts in the study area. Results show a K value of almost 0.92 for the classifier with best results, random forest. Sensibility of each feature is assessed, showing that both distance and height difference from nearest road-side are more significant than overall DTM value.

Indicators of environmental performance to assess wood-based bioenergy production: A case study in Northern Italy

Increased environmental concerns, mainly related to fossil fuels consumption and global climate change, have drawn the attention to the dependence of human society on energy supply. As a consequence of EU Directives setting mandatory renewable energy targets up to 2020, member states are boosting renewable energy and bioenergy production. The use of wood biomass for bioenergy production can entail important benefits, including improved energy security due to a smaller dependence on fossil fuel supply, mitigation of climate impact, and revitalization of rural economies connected to new job opportunities. Nevertheless, bioenergy production also involves environmental and socio-economic concerns. The environmental, economic, and social sustainability of bioenergy production needs to be assessed through a set of multicriteria indicators. In this study, Life Cycle Assessment (LCA) was used to explore the environmental performance of bioenergy production in an Alpine area of Northern Italy. In particular, the environmental impacts of a wood-based bioenergy plant utilizing local residues from wood industries and forestry operations were investigated. The amount of CO2-eq emissions (0.25 kg CO2-eq kWh−1) and the fossil demand (0.09 kg oil-eq kWh−1) calculated for the investigated bioenergy plant resulted lower than the values characterizing fossil fuels-based power plants. Yet, the environmental performance of the investigated bioenergy plant was affected by the consumption of methane, still used in the plant to cover peak loads. The results showed that the use of local wood biomass in the investigated Alpine area is a desirable option for recycling wood residues while supporting heat and electricity production. The findings of this study can support local managers and policy makers committed to plan and implement renewable energy strategies and circular economy patterns. In addition, they can be useful to assess the potential upscale of this bioenergy option at regional and national level considering the availability of wood residues (from forestry and industrial sector) while verifying possible operational constraints at larger scales. Future studies could also integrate environmental accounting with other assessment methods exploring the economic profitability and social desirability of wood-based bioenergy production in mountain areas characterized by low population density and large forest cover.

Impact of compaction on two sensitive forest soils in Lorraine (France) assessed by the changes occurring in the perched water table

The mechanisation of forestry operations is too recent in France to have enough perspective and scientific knowledge of the effects on extensively managed soils. Two experimental sites on soils sensitive to compaction (silty acidic soils laying on top of a clayey subsoil) were set in Lorraine (France). A gentle and controlled compaction of these physically very analogous soils was carried out during spring 2007 at the Azerailles site (AZ) and during spring 2008 at the Clermont-en-Argonne site (CA). Immediate changes were observed for all ecosystem physical, chemical and biological functioning indicators. Soil restoration dynamics were followed using continuous monitoring of numerous parameters, including soil moisture and occurrence of a perched water table (PWT) (monitored at a daily time step) and PWT chemistry (monthly time step). Mid-term monitoring (7–8 years) results showed that both soils shifted towards a hydromorphic soil type attested by the increase in PWT frequency and duration, which invaded the soil upper layers, leading to characteristic Fe, Mn and S mobility and a change in organic compounds stability. Though soil types were very similar, the PWT characteristics varied notably between both sites. The mean residence time of the PWT was shown to be a major driver of its geochemistry, but with strong interaction with soil characteristics. A previous study made on both sites suggested that soil clay content and clay mineralogy controls the PWT dynamics through effects on aggregation. From a PWT perspective, seven years of monitoring were insufficient to observe any soil compaction recovery in the richer soil of AZ but a partial recovery was observed for the chemically poorer soil (CA). Compaction durably impacted the two studied soils and the probability that a new compaction event may occur before the complete recovery from the first disturbance must be considered in forest management.

Are community forests a viable model for the Democratic Republic of Congo?

Since the second half of the 2000s, several options for implementing community-based forest management in the Democratic Republic of Congo (DRC), like the local community forest concession (LCFC), have been discussed in the country's technical and political circles. Proposals and pilot testing have increased in the last five years, but the funding of initiatives is often proposed for divergent purposes and taking different approaches. We reviewed current experiences in the Eastern province of the DRC and found that nobody has carried out an estimation of the financial returns of the business models they drew up for/with the communities involved. We therefore conducted a financial feasibility analysis for two case studies, estimating the costs of developing/implementing activities and the benefits expected for the communities within the next five years. Three main conclusions were drawn from the analysis: (1) most activities conducted under the LCFC model deal with rural development, and not with forestry operations per se; (2) several forestry activities such as biodiversity conservation or carbon sequestration are not detailed in the management documents and appear to have little legitimacy for local populations; (3) the two LCFCs show a negative financial performance because the inception and implementation costs are substantially higher than the medium-term profits. Community forestry is unlikely to develop in the DRC unless local people are guaranteed that it will contribute to improving their livelihoods, notably their financial and physical capital. This requires that LCFC initiatives focus on actual productive uses of forest resources, which financial performance is systematically assessed ex ante. A simplification of the legal constraints is also needed to reduce the cost of creating and managing a LCFC.

Modeling residual biomass from mechanized wood harvesting with data measured by forest harvester.

The lack of accurate models for estimating residual biomass in wood harvesting operations results in underutilization of this co-product by forestry companies. Due to the lack of this information, forestry operations planning, such as chipping and transport logistics, are influenced, with a consequent increase in costs. Thereby, the aim of this study was to propose and evaluate statistical models to estimate residual biomass of Eucalyptus sp. in wood harvesting operations by means of tree variables measured from harvester processing head. Generalized linear models were composed through stepwise procedure for estimating residual biomass by tree covariates: diameter at breast height, commercial height, commercial limit diameter, and stem commercial volume, considering also their transformations and combinations. Residual biomass distributions with positive skew support the application of generalized linear model and Gamma distribution in random component, since normality assumption in traditional linear regression was a requirement not satisfied in this study. By stepwise procedure, tree variables associated to forest biomass were selected, whose linear combinations resulted in models with high statistical efficiency and accuracy. Thus, models developed in this study are innovative tools to estimate residual biomass in mechanized wood harvesting, in which can be inserted into harvester's hardware to provide real-time information.

Classifying soil stoniness based on the excavator boom vibration data in mounding operations

The stoniness index of forest soil describes the stone content in the upper soil layer at depths of 20–30 centimeters. This index is not available in any existing map databases, and traditional measurements for the stoniness of the soil have always necessitated laborious soil-penetration methods. Knowledge of the stone content of a forest site could be of use in a variety of forestry operations. This paper presents a novel approach to obtaining automatic measurements of soil stoniness during an excavator-based mounding operation. The excavator was equipped with only a low-cost inertial measurement unit and a satellite navigation receiver. Using the data from these sensors and manually conducted soil stoniness measurements, supervised machine learning methods were utilized to build a model that is capable of predicting the stoniness class of a given mounding location. This study compares different classifiers and feature selection methods to find the most promising solution for this learning problem. The discussion includes a proposition for a meaningful measurement resolution of the soil’s stoniness, and a practical method for evaluating the variability of the stone content of the soil. The results indicate that it is possible to predict the soil stoniness class with 70% accuracy using only the inertial and location measurements.

Opodatkowanie podmiotów prowadzących działalność leśną w związku z ustanowieniem na posiadanych przez nie gruntach służebności przesyłu – w świetle najnowszego orzecznictwa

Opodatkowanie podmiotów prowadzących działalność leśną w związku z ustanowieniem na posiadanych przez nie gruntach służebności przesyłu – w świetle najnowszego orzecznictwa

Perspectives of Private Forest Owners toward Investment in Forest Carbon Offset Projects: A Case of Geumsan-Gun, South Korea

Understanding and promoting South Korean private forest owners’ investment in the Forest Carbon Offset (FCO) scheme is crucial for enhancing carbon sequestration using forests in South Korea. This study aims to identify the factors of private forest owners associated with the investment decision in FCO projects. A total of 132 forest owners in Geumsan-gun, Chungcheongnam-do responded to a mixed-method survey. A chi-square test on the respondent groups shows that a forest management contract has a positive correlation with the forest owners’ willingness to invest in FCO projects. We also developed a logistic regression model for each forest owner group to estimate the effects of forest characteristics, experience of financial support, forest owner characteristics, and management characteristics on the forest owners’ willingness to invest in FCO projects. The results indicate that beliefs in climate change, size of forest holdings, tree species, stand age, experience in cost-sharing for forestry operations with public agencies, and timber harvest experience were significantly associated with the likelihood of a forest owner’s willingness to invest in FCO projects. Therefore, forest policies should take account of the factors influencing the likelihood of forest owners’ investment in FCO projects. We also found that the forest management contract scheme can be used as a policy instrument for promoting private forest owners’ action for climate change in South Korea.

Assessment of soil physical properties' statuses under different land covers within a landscape dominated by exotic industrial tree plantations in south-central Chile

Land use and land cover changes (LULCC) within a highly anthropized Mediterranean landscape dominated by industrial tree plantation leads to degradation of soil physical properties. This process has been more intense in the coastal range of south-central Chile due to its soils, which are highly susceptible to erosion, combined with a long history of intensive land use changes during the last century, transitioning from native forest (NF) to agriculture and the more recent establishment of Pinus radiata and Eucalyptus spp. exotic tree plantations. In this context, the aim of this study was to assess the statuses of soil physical properties over different land cover situations. Historical land cover maps were determined via supervised classifications using the maximum likelihood classifier applied to satellite imagery. Five land use and land cover categories (LULC) were defined according to main land cover transitions associated with active and abandoned forestry operations that have been reported in the region: NF, pine plantation (P), eucalyptus plantation (Eu), early successional (E-S), and secondary successional (S-S). Successional stages were generated using change detection statistics considering changes between 2001 and 2014 maps. Soil samples were collected at three depths in 39 plots that describe the five LULC. High clay contents were found in all the LULC except Eu and P. These sites have shown more signs of degradation, with lower organic matter (SOM) and macropores and higher shear strength (ShS). Soil organic matter was consistent with litter contribution and quality, establishing lower bulk density (Db) for NF and S-S and higher values for Eu and E-S. ShS and dispersion rate (DR) exhibit a correlation with SOM with lower ShS and higher DR when SOM increased. Relevant differences were identified for structural stability index (SSI) between LULC depending on soil physical quality, besides a positive correlation with SOM. Those results show the need to generate appropriate conditions of vegetation cover in order to recover soils subjected to current forestry management of industrial plantations.

Reducing the exhaust emissions of unregulated pollutants from small gasoline engines with alkylate fuel and low-ash lube oil

We report exhaust emissions of regulated and unregulated gaseous compounds (aromatic, oxygenated, and nitrogen-containing compounds), particle mass and soot content for a series of 5 utility hand-held machines typically used in gardening and forestry operation in Europe. The engines were tested in the Vehicle Emissions Laboratory of the European Commission – Joint Research Centre. Two fuels, standard and alkylate fuel (trace content of aromatics), and 2 lubricant oils (semi-synthetic and low-ash) were used. With the standard fuel, we observed average emissions from 8 g/h up to 103 g/h of hydrocarbons and from 162 g/h up to 275 g/h of carbon monoxide (regulated compounds). A consistent fraction of aromatics was identified in the exhaust: 5–10 g/h of toluene and 1.7–3 g/h of benzene for the 2-stroke engines (below 0.6 g/h for the 4-strokers). The use of the alkylate fuel resulted beneficial in the reduction of several chemical species, in particular all the monitored aromatics (70–100% reduction) and the soot content of the emitted particles (27–90% reduction). These reductions can mitigate the adverse health effects of some toxic or carcinogenic compounds (e.g. toluene and benzene) especially for professional users with high exposure risk. The use of the low-ash lube oil had a lower impact than the fuel change and was engine- and compound-specific. The carbon monoxide emission limit reduction and the introduction of the alkylate fuel would be already feasible actions based on this study and existing scientific literature.

TO THE QUESTION OF OPTIMISING THE DYNAMIC CHARACTERISTICS OF A VIBRATIONAL TREE UPROOTING MACHINE

ObjectivesFollowing logging operations, tree stumps remain in the site of the former forest.While these may be uprooted by special machines in the course of forestry operations, the use of heavy forestry machines operated repeatedly on the forest sites not only lead to soil erosion, but also to considerable financial expense. Consequently, the development of machines combining cutting (logging) and uprooting operations – that is, uprooting the trees along with their roots – are of a great interest. As research has shown, the main disadvantages of the use of such technology by “conventional” logging or forestry machines are their excessive loading and energy intensity. The aim of the research is to investigate means of eliminating these drawbacks by using vibration.MethodsThe article deals with theproblem of ensuring the effectiveness of the vibration application – in particular, torsional vibrations, used to stub trees together with their roots. To solve this problem, a mathematical model of the “machine-tree-soil-root system” system was developed, which takes into account the mutual influence of the dynamic characteristics of the machine’s technological equipment and tree and soil-root system, which allows a rational (optimal) frequency range of vibration equipment to be selected by analysing the amplitude-frequency characteristics of a given system. To analyse the amplitude-frequency characteristics of a mechanical system, the Euler-Lagrange equationswere used.ResultsBased on the mathematical model of the “machine-tree-soil-root system (SRS)” system and an analysis of the amplitude-frequency characteristics of a given system, a rational range of vibration frequencies was determined. As shown by analysis, the work of vibrational equipment in a given frequency range can significantly reduce the dynamic loading of the machine and at the same time create appropriate conditions for the effective destruction of the soil-root system.ConclusionThe proposed method allows the rational values of the frequency characteristic of vibration equipment for each calculated tree to be found depending on the soil type and the basic machine.

Volunteering for Forest Health: A Public-Private Partnership in Oakville, Ontario, Canada

The Forest Health Ambassador Program, a joint public-private initiative in Oakville, Ontario, Canada, recruits volunteers from the community to assess municipal street trees for health issues and signs of invasive insects. In partnership with municipal employees, staff from BioForest, a private consultant, trains volunteers to inspect trees for a suite of structural and foliar conditions, as well as for signs and symptoms of infestation by emerald ash borer, gypsy moth, and Asian longhorned beetle. Since 2014, 4,871 street trees have been assessed by a growing base of volunteers. The program effectively increases the number of participants involved in the early detection of invasive pests, beyond what government resources typically allow. Thus, the program entails a low-cost investment that provides multiple ancillary benefits and channels community efforts into a cohesive product. The results provide data with direct implications for municipal forestry operations and help identify trends in urban forest health over time. For example, detections of relatively high numbers of gypsy moth egg masses were reported by volunteers, allowing the municipality to take remedial action and mitigate damage. A variety of media are used to advertise the program, including community newspapers and social media, as well as communications in local schools and at community events. The program is well-suited to high school students, who are able to complete curriculum-mandated volunteer hours through the program, while simultaneously gaining environmental knowledge. The program allows for the proliferation of awareness and education pertaining to municipal urban forest issues, particularly those related to invasive species and urban tree health.

Source areas, connectivity, and delivery rate of sediments in mountainous-forested hillslopes: A probabilistic approach

In mountainous-forested landscape, quantifying the materials produced at hillslope scale that effectively reach the channel network with a given probability is currently challenging, due to the uncertainties in modelling the frequency-magnitude distribution of failures and in determining the sediment connectivity between unstable areas and channel network.The purpose of this study is to develop a modular approach to assess the sediment source areas and the probability of mobilization from hillslope, and to estimate the probability of sediment input to the streams proposing a new connectivity index.The first goal was faced adopting a 3D probabilistic slope stability method that includes the spatially distributed characteristics of forest coverage. The second aim was tackled by comparing sediment travel distance and the minimum-topographic distance to reach the nearest stream. A simple deposition model was applied to estimate the percentage of the sediment entering into the stream network.The methodology was tested on three headwater catchments in northern Italian Alps. The outputs were landslide susceptibility maps, which showed robust performances when compared to the available landslide inventories (AUC > 0.726), and maps of the probability that sediment reaches the channel network. In this way, it was possible to identify which areas are the most susceptible to landsliding, how many sediment materials can be mobilised with a given probability, and which is the degree of sediment connectivity with the channel system. Results obtained for the tested catchments, compared with data available from the literature, showed that the proposed methodology is of general validity, especially for those territories characterized by rainfall-triggered landslides and forest coverage.This study, then, provides a robust framework to improve debris-flow risk management and to implement watershed management strategies, such as planning forestry operations or positioning retention structures addressed to increase slope stability and to reduce sediment delivery.