Comparative assessment of the ecological state of Timiryazevsky district forest park zones in Moscow

The article presents the results of a comparative environmental assessment of the quality of the environment in the central and outlying zones of two forest parks, contrasting in area, types and magnitude of anthropogenic load, - the Experimental Forest Station and the Dubki Culture and Recreation Park, located in the Timiryazevsky district of Moscow. The quality of the environment in the undisturbed forest biocenosis in the center of the Experimental Forest Station corresponded to the quality of the environment in the rural areas of the Moscow Region, while the environmental situation in the outlying zones of both forest parks bordering various urban infrastructure facilities deviated to varying degrees from the conditional norm. The worst indicators of the environmental quality and forest stand conditions were noted in the recreational zones located at the III-IV stage of digression, as well as in the zones bordering the roads, within which the degree of fluctuating asymmetry of birch leaves was suspended and the cellulolytic activity of the soil was 1.5-2.5 times lower than the background. The combination of recreational and transport loads reduced the quality of the environment in the Dubki park to a critical level. Keywords: CITY FOREST, BORDERLAND, ANTHROPOGENIC LOAD, POLLUTION, RECREATION, DEGRADATION, FLUCTUATING ASYMMETRY, CELLULOLYTIC ACTIVITY, APPLICATION METHOD, AIRBORNE POLLUTION, SNOW COVER

Terrestrial Laser Scanning for Quantifying Timber Assortments from Standing Trees in a Mixed and Multi-Layered Mediterranean Forest

Timber assortments are some of the most important goods provided by forests worldwide. To quantify the amount and type of timber assortment is strongly important for socio-economic purposes, but also for accurate assessment of the carbon stored in the forest ecosystems, regardless of their main function. Terrestrial laser scanning (TLS) became a promising tool for timber assortment assessment compared to the traditional surveys, allowing reconstructing the tree architecture directly and rapidly. This study aims to introduce an approach for timber assortment assessment using TLS data in a mixed and multi-layered Mediterranean forest. It consists of five steps: (1) pre-processing, (2) timber-leaf discrimination, (3) stem detection, (4) stem reconstruction, and (5) timber assortment assessment. We assume that stem form drives the stem reconstruction, and therefore, it influences the timber assortment assessment. Results reveal that the timber-leaf discrimination accuracy is 0.98 through the Random Forests algorithm. The overall detection rate for all trees is 84.4%, and all trees with a diameter at breast height larger than 0.30 m are correctly identified. Results highlight that the main factors hindering stem reconstruction are the presence of defects outside the trunk, trees poorly covered by points, and the stem form. We expect that the proposed approach is a starting point for valorising the timber resources from unmanaged/managed forests, e.g., abandoned forests. Further studies to calibrate its performance under different forest stand conditions are furtherly required.

Sampling with probability proportional to prediction (3P sampling) using covariates derived from spherical images

Using a two-phase sampling approach with systematic selection of large samples of covariates followed by a sampling with probability proportional to prediction (3P sampling) process to subsample field measures of the parameters of interest can be an efficient design to sample larger forest areas. To assist in obtaining predictions for each sample plot consistently and rapidly, we propose using a 360° spherical camera. In this study, three covariates derived from spherical images were evaluated: (i) basal area (P[BA]); (ii) sum of squared heights per hectare (P[SHT]); and (iii) stem fraction (P[SF]). These covariates were used to estimate volume. Sample simulations showed no biases in volume estimates for any of the three covariates. Overall, P[SF] had the lowest standard error percentages across different simulated sample sizes (10% for five subsamples to 2.5% for 50 subsamples), even though it had the lowest correlations with field volume (correlation = 0.30–0.31). This may be a result of the relatively consistent stand conditions within the study site. Based on our results, standard errors of 5% were obtainable with measurement fractions of about 25% of the number of image-based predictions when using P[SF] or P[BA] and 75% when using P[SHT].

Effects of Permanent and Temporary Edges on Pinus clausa (sand pine) Architecture and Stand Conditions

Effects of permanent (i.e., maintained) and temporary edges with north- and south-facing exposures were studied in sand pine (Pinus clausa var. clausa) scrub, an open-canopied forest type in Ocala National Forest, Florida. On edges and interiors of four stands of each type, we measured canopy tree architecture in 5 x 100 m plots and stand density and basal area in 5 x 200 m plots. Edge effects were modest but often stronger on south- than north-facing edges and along permanent forest roads than temporary edges of clearcuts that were allowed to regrow. Compared to interior trees, those on edges were typically shorter, retained branches lower on their boles, oriented their first branches more towards the edge, and produced more asymmetrical crowns with the long axis extending into the opening; these trends were greater on south- than north-facing edges and along permanent than temporary edges. Contrary to expectations, there were no edge effects on total basal area, dead tree densities, proportions of sand pine trees with leaning trunks, directions of lean, or angles of lean. Instead of an edge effect, most trees leaned southwesterly, which seems related to the northeastern origin of prevailing winds and wind gusts.

Control and measuring modernization systems of the “Soil Channel” stand and the development of a wheel motion mathematical model in stand conditions

Introduction (problem statement and relevance). A promising direction for reducing a vehicle moving energy is the application of adaptive laws for controlling the power supplied to the propeller based on neural networks. To create a training array of the latter, a large set of experimental data is required, the collection of which, as a rule, is carried out by using research stands, such as the “Soil Channel”. But the fi eld studies require a lot of resources.The purpose of the study was to create a wheel rolling mathematical model in the conditions of the stand, with the help of which it would be possible to organize the collection of needed statistical data on the wheel rolling modes by calculation them in an automatic mode.Methodology and research methods. The paper describes the “Soil Channel” bench test, held by the Department of “Multipurpose tracked vehicles and mobile robots” of Bauman Moscow State Technical University. A list of the control and measuring systems components used in the process of its modernization in order to automate the collection of experimental data was considered. The “Soil Channel” stand mathematical model was presented which was based on the use of experimentally obtained dependences of the specifi c longitudinal thrust force on sliding and the specifi c longitudinal thrust force on the specifi c circumferential force.Scientifi c novelty and results. The developed mathematical model has been verifi ed on the basis of the data obtained in the course of fi eld studies. Conclusions were made about the suitability of the developed mathematical model of wheel motion under the stand conditions for conducting virtual experiments.Practical signifi cance. The data obtained by applying the developed mathematical model can be used to create a training array of a neural network to provide the implementation of adaptive laws for controlling the power supplied to the propeller.

Assessing Tree Mortality Probability in Harvested Hardwood Stands Using Long-Term Forest Inventory Data

Partial harvesting (here defined as removal of ≤50% of preharvest volume) is the predominant silvicultural scheme applied to hardwood forest types in the eastern United States. Future stand conditions are largely reliant on trees retained after harvest, so their mortality because of harvesting activity damage should be minimized or taken into account when planning. We quantify partially harvested stand characteristics and postharvest mortality using data from 32,057 forested conditions, 366,953 trees with a diameter at breast height (dbh) ≥ 2.5 cm, of which 4,469 trees were cut and used in partially harvested stands. On average 23.3% of stand volume was selectively harvested with an additional 2.5% of volume lost to harvesting-caused mortality. Of the trees killed by logging activity in harvested stands, 90.7% were under 28 cm dbh. The likelihood of mortality was 1.31 times higher (95% CI of 1.20 to 1.44) for trees retained in stands that had undergone partial harvesting than for trees growing in unharvested stands. Commercial species had lower odds of mortality (0.88 times) in harvested stands than noncommercial species. Residual trees in harvested stands on private lands had a higher probability of mortality (1.23 times) than those on harvested public lands.

Intelligent Pubescent Oak Forests (Quercus Pubescens Wild.) From Dobroudja Plateau, Romania

Dobrudjea Plateau, located in south-east Romania, is characterized by low altitudes, old rocks, a temperate-continental climate and a silvosteppe and steppe vegetation. Pubescent oak is one of the tree species characteristic for this area. With average dimensions, this tree fulfils numerous ecosystem functions. The concept of “Climate-Smart Forestry – CSF” is recent and was adapted in this article for the pubescent oak characteristic for this area; clear and measurable criterions were also identified and applies for this species in order to identify the smart stands. Smart pubescent oak forests represent 3% of all this specie’s stands and are more common in the north part of Dobrudjea Plateau. They are characterized by advanced ages (61-70 years), 20%-30% compositions and even-aged structures. The forests are located on relatively small distances from forest roads, at altitudes of 100m - 250 m, and on west and east expositions. The present study has showed that smart pubescent oak forests can be established by taking into account 14 site (flora, soil or forest type) and stand conditions (pruning, vitality, average diameter and height, functional group and category, litter). The identification of these stands is extremely important for their protection as well as for applying the appropriate silvicultural measures.

The Valuation of Thinning Efectivity Based on Increment Respond of Natural Forest Log Over Area

Efforts to increase the natural forest productivity was conducted using several ways one of which is through thinning but the effectiveness is not well known yet. The research aims to evaluate the effectiveness of the application of thinning techniques to logged-over natural forests based on the response of the stand increment. The study design was an 11-year-old logged-over natural forest stand that was carried out systematic thinning, thinning based on built trees and without treatment with a total area of 24 ha. Data collection is done by census inventory of trees with limit diameter of 10 cm per 2 years periodically. Stand conditions in the research plot varied in value range of density (419-510 stems ha-1) and the base plane (22.66-28.20 m2.ha-1) which were not too wide. The results of the calculation of the base plan of the stand shows that systematic thinning yields a larger stand increment (0.78-1.95 m2.ha-1.2th-1) compared to thinning based on built trees and without treatment. Thinning gives more responsive results for the Dipterocarp species group (the increment value is almost twice to normal) compared to non Dipterocarp. Based on the regression analysis, function of time period has correlation between 25-33% to the basal area increment. A systematic thinning technique approach that is more appropriate for increasing stand productivity.