Forest Management Activities Research Articles

How thinning in a seasonally dry tropical forest contributes towards root biomass, carbon stock and aggregate size in a Vertisol

Forest management activities influence fine root development, total soil carbon (TSC) and size of aggregates. A field experiment was carried out in Vertisols of two adjacent catchments in a seasonally dry tropical forest (SDTF) to investigate the thinning on fine-root biomass, stock of the total soil carbon and aggregate size. The catchments are located in the State of Ceará, Brazil. The control catchment of 2.1 ha has been under regenerating vegetation for 35 years (RC35), while the second catchment (1.1 ha) was subjected to thinning (TC5) in December of 2008. The analysed variables were: fine-root biomass in the 0-10, 10-20 and 20-30 cm soil layers, TSC and mean weight diameter of the soil aggregates in the 0-20, 20-40 e 40-60 cm layers. The data were submitted to Pearson correlation analysis and compared by paired t-test (P < 0.05). The 0-10 cm layer of the TC5 management stored double the average amount of fine-roots found in the RC35. Under the TC5 management, stocks of soil TSC increased by 237 and 151% in the 20-40 and 40-60 cm layers, respectively, when compared with RC35. Aggregates 2.15 times greater than those found under RC35 management were obtained in the topsoil (0-20 cm) under the TC5 management. The implementation of thinning in a Vertisol of a SDTF emerges as an alternative management to be considered in projects for sustainability in the semi-arid region, contributing to an improvement in soil structure as well as an increase in the stocks of total carbon.

Modeling land use change and forest carbon stock changes in temperate forests in the United States

BackgroundForests provide the largest terrestrial sink of carbon (C). However, these C stocks are threatened by forest land conversion. Land use change has global impacts and is a critical component when studying C fluxes, but it is not always fully considered in C accounting despite being a major contributor to emissions. An urgent need exists among decision-makers to identify the likelihood of forest conversion to other land uses and factors affecting C loss. To help address this issue, we conducted our research in California, Colorado, Georgia, New York, Texas, and Wisconsin. The objectives were to (1) model the probability of forest conversion and C stocks dynamics using USDA Forest Service Forest Inventory and Analysis (FIA) data and (2) create wall-to-wall maps showing estimates of the risk of areas to convert from forest to non-forest. We used two modeling approaches: a machine learning algorithm (random forest) and generalized mixed-effects models. Explanatory variables for the models included ecological attributes, topography, census data, forest disturbances, and forest conditions. Model predictions and Landsat spectral information were used to produce wall-to-wall probability maps of forest change using Google Earth Engine.ResultsDuring the study period (2000–2017), 3.4% of the analyzed FIA plots transitioned from forest to mixed or non-forested conditions. Results indicate that the change in land use from forests is more likely with increasing human population and housing growth rates. Furthermore, non-public forests showed a higher probability of forest change compared to public forests. Areas closer to cities and coastal areas showed a higher risk of transition to non-forests. Out of the six states analyzed, Colorado had the highest risk of conversion and the largest amount of aboveground C lost. Natural forest disturbances were not a major predictor of land use change.ConclusionsLand use change is accelerating globally, causing a large increase in C emissions. Our results will help policy-makers prioritize forest management activities and land use planning by providing a quantitative framework that can enhance forest health and productivity. This work will also inform climate change mitigation strategies by understanding the role that land use change plays in C emissions.

Influence of logging on nest density and nesting microsites of cavity-nesting birds in the subtropical forests of the Andes

Abstract Birds select nesting sites with certain characteristics associated with tree age and species that help to prevent or reduce the risk of clutch loss due to predation or unfavourable weather conditions. Logging may reduce the availability of trees and their related features that may be important for cavity nesters. Thus, the aim of this study is to evaluate the effect of logging on nest density, nesting microsite and nest success of cavity nesting birds at Piedmont forests of northwestern Argentina. We monitored these variables at different logged and unlogged sites during four consecutive reproductive seasons and analysed them using univariate analysis and generalized linear models. The main results indicate that logging reduces nest density and changes the characteristics of the nesting microsites. We found that nest success was greater in cavities located higher above the ground and found no evidence of lower nest success at logged sites. This study suggests the need for forest management actions aimed at increasing nesting sites for cavity-nesting birds. For this purpose, management should be focused on the retention of old trees with a diameter >50 cm (both living and dead). The use of reduced-impact logging techniques or forest certifications (e.g. Forest Stewardship Council) could provide alternatives in subtropical forests, as these forestry practices can ensure tree abundance and richness, providing features suitable for cavity-nesting birds (e.g. tree diameter, cavity size and height).

Long-term impacts of silvicultural treatments on wildland fuels and modeled fire behavior in the Ridge and Valley Province, Virginia (USA)

Active forest management operations, such as regeneration harvests, can reduce hazardous fuel loads and alter fuel structure, potentially minimizing extreme wildfire conditions while maintaining ecosystem services, such as wildlife habitat and water quality. Regeneration harvests of differing intensities (clearcut, high-retention shelterwood, and low-retention shelterwood) were first applied between 1995 and 1996 to three sites on the George Washington-Jefferson National Forest in the Ridge and Valley Province of Virginia, USA. Over two decades after the clearcut was conducted and 11–12 years after the overwood was removed in the shelterwood stands, woody debris, litter, and duff masses and depths were quantified. One-hour fuel loads were greater in clearcut units than in high-retention shelterwood, low-retention shelterwood, or control units. Ten-hour fuel loads were greater in clearcut and low-retention shelterwood units than in high-retention shelterwood and control units. No significant differences in 100-hour fuels were observed between treatments. Control units contained more rotten and total 1000-hour fuels than all other treatments. The total woody debris load was less in the clearcut and high-retention shelterwood than in the low-retention shelterwood and control. High-retention shelterwood woody fuel depth was greater than clearcut woody fuel depth. Litter and duff loads were less in treated units than in the control units. Total fuel load (woody fuel load + litter load + duff load) was greater in the control than the silvicultural treatments. Litter depth did not differ between treatments, while duff depth was greater in the control than in the treated units. Using the computer modeling software, BehavePlus 6.0.0, these alterations to fuel loads and depths led to increased values in the control units for six fire behavior parameters. Predicted surface flame length in the low-retention shelterwood was the only modeled value that was not less than control values. Overall, these results indicated that harvest intensity and timing may have long-term effects on down and dead woody fuels, forest floor depth, and potential fire behavior. Clearcutting reduced fire behavior most, followed by the high-retention shelterwood system. The potential differences in slash and debris generated by varying shelterwood systems may impact long-term fuel and fire dynamics.

Forest management alters alpha-, beta-, and gamma diversity of saproxylic flies (Brachycera) in the Hyrcanian forests, Iran

Forest management can cause a loss of biodiversity associated with dead wood. Today, vast areas of unmanaged temperate forests are protected forests in the Hyrcanian region in northern Iran. The Hyrcanian forest hosts large numbers of endemic species, grounding its high conservation value. However, few studies have investigated the possible impact of increasing forest management activities in these forests. We surveyed saproxylic flies in 30 managed and unmanaged plots across the entire Hyrcanian forest between 2017 and 2019 with pan traps. Overall, we collected 71 species belonging to 22 families. Forest management resulted in decreasing abundance and species richness, as well as in an altered community composition. Chloromyia speciosa (Macquart, 1834), Sargus cuprarius (Linnaeus, 1758), Pherbellia jalili Mortelmans and Kazerani, 2020, Dolichocephala sp. and Bibio sp. were bioindicators for unmanaged plots. Indicator species suggest that changes in the biodiversity of saproxylic flies where primarily linked to the management-caused loss of old-growth attributes, such as large decaying logs and fruiting bodies of wood-inhabiting fungi. Endemic species as well as rare families of saproxylic flies illustrate the importance of conserving unmanaged parts in the Hyrcanian forest.

Symbolic interaction and its influence on cooperation between private forest owners

Organizations, such as forest management cooperatives (FMCs), are established to support private forest owners to deal with structural and natural challenges that they cannot handle on their own. In 2018, Feil et al. found in a nationwide survey that only 30% of German private forest owners are members of FMCs. This low participation rate of private forest owners in FMCs in Germany poses a problem for the further development of organizations that can better consider the needs of private forest owners and also meet the timber market's long-term requirements for larger quantities of timber as well as become an equal negotiation partner of the sawmill industry. This problem can be attributed to social interactions, which are considered influential for cooperation between private forest owners.This paper aims to highlight different groups of private forest owners in Germany and their cooperation based on social interaction. To do so, it refers to the categories of actor-centered institutionalism (ACI) and complements these with symbolic interactionism. Methodologically, the paper is based on a quantitative online survey of 1007 private forest owners in Germany. The survey itself was prepared by the authors and conducted by the pollster firm forsa, Germany in the period from 14 to 29 July 2020. In addition to standard research topics in forest related research, such as family tradition and income generation, the questionnaire also focused on social interaction. A hierarchical cluster analysis based on the values of a principal component analysis (PCA) was used both to ensure a neutral view on the data and to create heterogeneous groups of private forest owners.Four distinct clusters were defined through the cluster analysis: “actively exchanging”, “perceivers”, “uninterested” and “self-referential”. These clusters differ mainly in relation to their preferred forms of social interaction.It can be concluded that not only communication but also social interaction in the form of symbolic interaction has an influence on forest owners' cooperation with FMCs. For forestry practice, this means that in regions where there are currently no FMC members, new members could be won in the future by creating forest management activities that encourage cooperation with FMCs.

Habitat suitability and nest-site selection of short-toed eagle Circaetus gallicus in Tolfa Mountains (Central Italy)

The availability of a suitable nesting site can be an important limiting factor for the reproduction of birds of prey, which are highly influenced by forest management and exploitation activities. Among them, the short-toed eagle (Circaetus gallicus) seems to tolerate logging activities carried out with traditional practices. This study aimed to investigate the habitat selection of 29 territorial pairs of this species in the Tolfa Mountains (Central Italy). Using Generalized Linear Models and the Information-Theoretic Approach, we compared the environmental features (i.e. land cover and topography) that characterize nesting sites in the study area. Additionally, we described the nest-site selection of the species by characterizing nine detected nests and comparing their characteristics with those of an equivalent number of nearby randomly selected sites. We found that, as expected, the short-toed eagle settles on hillsides covered by broad-leaved forests (both evergreen and deciduous) with open areas and away from agricultural areas. Moreover, the nests were found on steeper slopes, on trees extensively covered with climbing plants, possibly to hide them from predators and human disturbance. Our results suggest that, for the conservation of the short-toed eagle, careful management of woodland coppicing is required, as well as greater control of human disturbance.

Net Revenue of Forest Carbon Offset Projects: Application of the Korean Emission Trading System in the Forestry Sector

Under the Korean Emission Trading System in The Forestry Sector (KETSF) initiative, the Korean government has developed several greenhouse gas (GHG) emissions reduction programs that include forestry activities as cornerstones of the initiative. Forest management is deemed to be a major strategy to implement KETSF; this has been confirmed by most participants in the program, who have shown their preference for forest management projects as the most effective and encouraging strategy to participate in the KETSF program. For a successful implementation of KETSF projects, it is essential to explore methods that optimize the positive impacts of such strategies, thereby maximizing the economic returns and carbon stocks that result from the implementation of forest management activities. Thus, this study investigated the economic returns of several KETSF projects in Korea, which included simulated scenarios under two main forest management strategies, one based on an extension of the rotation age, and a second one based on reforestation with new species. Five forest management scenarios were examined and evaluated in their ability to maximize carbon stocks and economic returns. Based on the results, two scenarios were identified as the best KETSF projects in terms of carbon stock increments. Additionally, the results indicated that projects including reforestation with new species added more economic value than projects that considered an extension of the rotation age. The study also revealed that KETSF projects generated revenue in both scenarios, by either extending the rotation age or by implementing reforestation with new species.

Active Forest Management Reduces Blacklegged Tick and Tick-Borne Pathogen Exposure Risk.

In the northeastern USA, active forest management can include timber harvests designed to meet silvicultural objectives (i.e., harvesting trees that meet certain maturity, height, age, or quality criteria). Timber harvesting is an important tool in enhancing regeneration and maintaining forest health. It also has considerable potential to influence transmission dynamics of tick-borne pathogens, which are deeply embedded in the forest ecosystem. We conducted a 2-year study to test the hypotheses that recent timber harvesting impacts blacklegged tick density and infection prevalence in managed nonindustrial forests. We found that (1) recent harvesting reduces the presence of nymphal and density of adult blacklegged ticks, (2) recently harvested stands are characterized by understory microclimate conditions that may inhibit tick survival and host-seeking behavior, (3) capture rates of small mammal species frequently parasitized by immature ticks are lower in recently harvested stands compared to control stands with no recent harvest history. In addition, a 1-year pilot study suggests that harvesting does not affect nymphal infection prevalence. Collectively, our results demonstrate that forest structure and understory conditions may impact ticks and the pathogens they transmit via a range of mechanistic pathways, and moreover, active forest management may offer sustainable tools to inhibit entomological risk of exposure to tick-borne pathogens in the landscape.

Bioeconomy Opportunities for a Green Recovery and Enhanced System Resilience

Bioeconomy Opportunities for a Green Recovery and Enhanced System Resilience

Estimation of Citizens’ Willingness to Pay for the Implementation of Payment for Local Forest Ecosystem Services: The Case of Taxes and Donations

The purpose of this study is to determine a valid strategy for implementing payment for the local forest ecosystem services (local forest PES) by considering citizens’ willingness to pay (WTP) and the resource types utilized (taxes and donations). A total of 1000 citizens responded to an online survey, which consisted of questions related to respondents’ socio-demographics, predicting factors (i.e., political orientation, personal tie to the region) of their willingness to pay (WTP), and their willingness to pay for a bundle of 10 different forest ecosystem services (ESs) in the region of the Yeoninsan provincial park in Gapyeong-gun, Gyeonggi-do, South Korea. The estimation of the respondents’ WTP for the promotion of the forest management activities, which enhances the ES bundle of the local forest, was 14,315–20,216 KRW (12.75–18.00 USD) per year in taxes and 12,258–26,518 KRW (10.92–23.61 USD) per year in donations. This study also revealed that the predicting factors influencing the respondents’ WTP for the promotion of the local forest ESs differed according to the financial resource type (taxes and donations). The results of this study are meaningful in that they can be used as empirical basic data in estimating payments and preparing measures to secure financial resources when designing payments for the ecosystem services for the local forest.

Bat responses to silviculture treatments: Activity over 13 years of regeneration

Using silviculture treatments as a tool to create habitat for wildlife is a common practice in wildlife conservation and natural resource management. Although diverse forest age structures and composition benefit many wildlife species, relatively little is known about bat response to young forest habitat. Understanding how the activity of bats changes as young forests age, and the influence of landscape level, stand level, and biologically relevant variables on bat activity, can improve effectiveness of forest management actions designed to benefit bat populations. We measured activity of bats in young forests regenerating from harvests implemented 2007–2018. We selected 26 sites, each of which consisted of a regenerating stand and paired control stand in adjacent interior forest, and used acoustic monitors to record bat activity from 5 May – 9 September 2019 and 2020, with a break from 1 July – 14 July so that monitoring fell into pre- or post-volant timeframes. We used an information theoretic approach to assess support for landscape level, stand level, and biologically relevant variables on bat activity in regenerating stands. Through our research we found (i) bats were more active in young forest stands than natural canopy gaps in interior forests, (ii) bat activity was highest in the first few years post treatment and decreased as young forests continued to age, and (iii) bat activity was highly dependent on biological factors, not landscape or stand level factors. Collectively, these findings suggest that forest management for young forest habitat may benefit forest-associated bats, at least in predominantly forested landscapes where young forest habitat is under-represented.

Модель объема ствола ивы: мета-анализ

Current scenarios of the consequences of global warming stimulate research on the carbon-depositing capacity of vegetation cover. The stem is the main part of the tree biomass, and the accuracy of its volume assessment determines the possibility of correct monitoring and forecasting of forest resources. In the Russian forest management system, willow was not among the main forest-forming species, and therefore there was no need to develop valuation standards for it. However, due to the increased relevance of assessing the carbon-deposing function of Russian forests and the requirement to take into account the contribution to the carbon balance of all types of vegetation, there is a necessity to develop such standards. The solution can be found in the development of a generic model (or table) that takes into account the morphology of willows within the Salix L. genus and is based on data published in different regions and countries. The object of our research is data on the volume of willow stems, which is published and freely available in Russia, Kazakhstan, Bulgaria, and Norway in the form of tables or regression models. However, the extent to which each local model is applicable in other regions is unknown. To resolve this uncertainty, we used meta-analysis as a statistical procedure that combines the results of several independent studies in order to find a common pattern. As a result, we obtained a generic model of stem volume for the Salix genus, which is characterized by a high coefficient of determination and can be applied to estimate the stem volume of any species of this genus with minimum deviations from the calculated values. The results of the work are aimed at improving the accuracy of accounting deciduous stands during forest management and monitoring activities, valuation of stands on permanent and temporary trial plots. The implementation of unified standards for the use, reproduction, conservation and protection of willow stands with all the diversity of its species will solve a number of practical issues. For citation: Usoltsev V.А., Paramonov А.А., Tretyakov S.V., Koptev S.V., Tsepordey I.S. Generic Model of Willow Stem Volume: A Meta-Analysis. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 49–58. DOI: 10.37482/0536-1036-2021-3-49-58

Diverging consequences of past forest management on plant and soil attributes in ancient oak forests of southwestern Iran

The oak (Quercus brantii Lindl.) semiarid forests of western Iran are among the oldest and host a remarkable diversity. However, the originally high forests were largely converted to coppices and submitted to a long history of traditional management and human disturbances. We investigated the effect of past management and forest structure on soil properties and vegetation diversity on two forest systems: coppice‐with‐standards stands abandoned after an intense period of exploitation (CWS) and high forest stands (HF) submitted to a low intensity of management. We selected in each system three 1–2 ha stands and sampled 30 plots to measure vegetation diversity, forest structure using structural indices and, main soil factors including bulk density, nutrients, organic carbon and porosity. We found a higher species diversity in HF than in CWS with respectively 7 woody species in the former and only 4 in the latter as well as a higher structural complexity. Plant composition differed also between the two systems and multivariate analyses revealed clear associations between vegetation composition and soil factors in particular soil nutrients, soil porosity for HF and bulk density and texture for CWS. In fact, contents in soil nutrients were higher in HF than in CWS for total nitrogen (0.28 vs 0.15%), available phosphorus (22.82 vs 15.47 ppm), available nitrogen (0.28 vs 0.15 ppm), and organic matter (2.58 vs 1.61%) whereas soils of CWS showed a higher bulk density (1.39 vs 1.29) and a lower porosity (47.66 vs 51.50%). This study thus revealed the legacy of the past forest management actions on the different components of the forest ecosystem. We concluded that the conservative management in high forests was more favourable for the protection of soil and vegetation diversity than in the traditional coppicing system.

Long-term response in nutrient load from commercial forest management operations in a mountainous watershed

An increased emphasis on fuel management strategies to mitigate wildfire risks is raising the awareness and need for comprehensive forest management strategies that satisfy long-term water quantity and water quality needs. Forest management activities can alter the soil nutrient pools and affect the timing and magnitude of stream water quantity and quality. We investigated the effect of contemporary forest management activities, including clear-cutting and thinning, on water yield and stream nitrogen and phosphorus dynamics in a quarter-century-long (1992–2016) paired and nested watershed study in the interior Pacific Northwest, US. Monthly water samples were collected and analyzed for total Kjeldhal nitrogen (TKN), total available nitrogen (TAN), nitrate + nitrite (NO3 + NO2), total phosphorus (TP), and orthophosphate (OP) concentrations throughout the study period. Five years of pre-disturbance data, 4 years of post-road construction, 6 years of Phase I (PH-I) experimental post-harvest, and 9 years of Phase II (PH-II) operational harvest data were analyzed using a before-after, control-impact paired series (BACIPS) study design. We found statistically significant increases in stream NO3 + NO2 loading from the paired and nested watersheds following timber harvest treatments. In the case of OP, any increase in nutrient load was attributed to increases in streamflow, as OP concentrations remained near minimum detectable concentrations. Streamflow increased the greatest following clear-cut practices (33.4% at W1 during PH-I) with the largest response in stream NO3 + NO2 concentration (up to 0.33 mg-N L−1 at W1). In-stream NO3 + NO2 and OP concentrations were lower in the downstream cumulative watersheds, which was likely due to dilution and nutrient assimilation effects. Interestingly, the NO3 + NO2 concentration, streamflow, and loads of NO3 + NO2 and OP from the undisturbed control watershed also increased. This increase was, however, smaller than the harvested watersheds and likely driven by climate variability or subtle forest succession changes. In summary, we found that contemporary forest management activities increased stream NO3 + NO2 concentrations and loads following timber harvest activities, but these effects were also attenuated due to downstream uptake processes. Furthermore, relative to post-wildfire impacts, these nutrient increases are small and short-lived.

Forest restoration increases isolated wetland hydroperiod: a long‐term case study

AbstractGeographically isolated wetlands (GIWs) are well known as “hotspots” for biodiversity and other ecosystem services, making their value on landscapes disproportionate to the area they occupy. GIWs are dependent on regular cycles of inundation and drying, which makes hydrology a primary controlling variable for sustaining functions and associated ecosystem services. Although human activity has degraded GIWs in many regions, relatively little work has focused on upland management as a way of sustaining, or even improving, GIW structure and function. We present a case study of longleaf pine forest restoration, by hardwood removal, on the characteristics of a wetland hydroperiod over a 10‐year study. Our study wetland, W‐51, is 0.89 ha with a catchment area of 31.2 ha located on a ~11,400‐ha private preserve in Baker County, Georgia (31.250° N, 84.495° W). Beginning in 2006, continuous water level and climate data were recorded in the wetland and adjacent well transects across the wetland catchment. In autumn 2009, hardwoods were removed or deadened in the catchment resulting in a 37% reduction in tree cover. The effects on the hydrologic system were measured through 2016 by examining pre‐ and post‐removal water levels, water yield ecosystem (WYe), and standardized recession rates (RRstd). The study included periods of above and below normal rainfall. Generally, wetland hydroperiods began in December and ended in May, but varied with rainfall pattern and amount. Hardwood removal increased WYe and decreased RRstd resulting in greater catchment water availability as reflected in water levels. Hardwood removal affected both the ascending and recessing limbs of wetland hydroperiods, substantially increasing the availability of ponded water in the wetland. Our results quantify changes in wetland hydrologic characteristics associated with forest management activities, which appear to have reduced forest water demand. Our study was a management case study, limited in scope but conducted in a realistic setting. More extensive studies (paired, replicated designs) are needed to better understand the implications at both the local scale, that is, managing critical aquatic habitat for wildlife populations, and at the regional scale, that is, providing support for landscape‐scale connectivity and water yields.

Rapid deforestation of a coastal landscape driven by sea-level rise and extreme events.

Climate change is driving ecological shifts in coastal regions of the world, where low topographic relief makes ecosystems particularly vulnerable to sea-level rise, salinization, storm surge, and other effects of global climate change. The consequences of rising water tables and salinity can penetrate well inland, and lead to particularly dramatic changes in freshwater forested wetlands dominated by tree species with low salt tolerance. The resulting loss of coastal forests could have significant implications to the coastal carbon cycle. We quantified the rates of vegetation change including land loss, forest loss, and shrubland expansion in North Carolina's largest coastal wildlife refuge over 35yr. Despite its protected status, and in the absence of any active forest management, 32% (31,600hectares) of the refuge area has changed landcover classification during the study period. A total of 1,151hectares of land was lost to the sea and ~19,300hectares of coastal forest habitat was converted to shrubland or marsh habitat. As much as 11% of all forested cover in the refuge transitioned to a unique land cover type-"ghost forest"-characterized by standing dead trees and fallen tree trunks. The formation of this ghost forest transition state peaked prominently between 2011 and 2012, following Hurricane Irene and a 5-yr drought, with 4,500±990hectares of ghost forest forming during that year alone. This is the first attempt to map and quantify coastal ghost forests using remote sensing. Forest losses were greatest in the eastern portion of the refuge closest to the Croatan and Pamlico Sounds, but also occurred much further inland in low-elevation areas and alongside major canals. These unprecedented rates of deforestation and land cover change due to climate change may become the status quo for coastal regions worldwide, with implications for wetland function, wildlife habitat, and global carbon cycling.

Managing forests for the future: Balancing timber production with the conservation of Eurasian red squirrel (Sciurus vulgaris)

Reconciliation of timber production and wildlife conservation is a major challenge in forest ecosystem management. For some protected species impacts of forest management are well documented, but for others such as the Eurasian red squirrel (Sciurus vulgaris) (hereafter ‘red squirrel’) they are still largely unknown. In Scotland, red squirrels are protected under national and international law and their presence needs to be carefully considered in forest management planning. This study investigated red squirrel responses to forest management activities and we specifically looked at the impact of standard thinning operations on red squirrel breeding activity, survival, population density and home range. From January to September 2017, we radio-tracked 22 individual red squirrels in a conifer plantation in the Highlands of Scotland, with standard thinning operations taking place during May 2017. Our results show that red squirrel survival was relatively high compared to sites without forest operations and breeding activity continued with no detectable impact of forest operations. Red squirrel population density was higher after thinning operations. Whilst space use changed for a handful of individuals, home ranges and core areas overall did not significantly change in response to thinning operations. Our findings suggest the impact of the standard thinning operations with a basal area reduction from 42 m2/ha to 32 m2/ha on red squirrels during the breeding season were minimal.

Early detection of bark beetle infestation in Norway spruce forests of Central Europe using Sentinel-2

In the past decade, massive outbreaks of bark beetles (Ips spp.) have caused large-scale decline of coniferous-dominated, prevailingly managed forests of Central Europe. Timely detection of newly infested trees is important for minimizing economic losses and effectively planning forest management activities to stop or at least slow outbreaks. With the advancement of Copernicus services, a pair of Sentinel-2 satellites provides a unique remote sensing data source of multi-temporal observations in high spatial resolution on the scale of individual forest stands (although not allowing for individual tree detection). This study investigates the potential for using seasonal trajectories of Sentinel-2 bands and selected vegetation indices in early detection of bark beetle infestation (so–called green-attack stage detection) in Norway spruce monoculture forests in the Czech Republic. Spectral trajectories of nine bands and six vegetation indices were constructed for the 2018 vegetation season using 14 satellite observations from April to November to distinguish four infestation classes. We used a random forest algorithm to classify healthy (i.e., stands not infested) and infested trees with various trajectories of decay. The seasonal trajectories of vegetation indices separated the infestation classes better than did the individual bands. Among the most promising vegetation indices we identified the tasselled cap wetness (TCW) component and normalized difference index constructed from near and shortwave infrared bands. Analysing the inter-annual change of the indices was more promising for early detection than is single-date classification. It achieved 96% classification accuracy on day of year 291 for the tested data set.The algorithm for early detection of tree infestation based on the assessment of seasonal changes in TCW was applied on the time series of Sentinel-2 observations from 2019 and its outputs were verified using field observations of forest conditions conducted on 80 spruce forest plots (located in spruce monoculture stands). The overall accuracy of 78% was achieved for the separation of healthy and green-attack classes. Our study highlights the great potential of multi-temporal remote sensing and the use of shortwave infrared wavelengths for early detection of spruce forest decline caused by bark beetle infestation.

ON MANAGEMENT OF PROTECTED FORESTS

The research on topics related to the management and organization of forest management activities in protected forests requires particular attention. Improving approaches to determining the most optimal forms of interaction between authorities and persons who use the forest. A vital priority in managing protected forests is the individual adjustment of the tools for evaluating its efficiency. The development of the forestry sector in the Republic of Crimea is possible through the improvement of the directions and tools of forestry management based on the collaborative efforts of the state and private institutions.