Characteristics Of Forest Stands Research Articles

Investigation of the Relationship between Topographic and Forest Stand Characteristics Using Aerial Laser Scanning and Field Survey Data

The article thoroughly investigates the relationships between terrain features and tree measurements derived from aerial laser scanning (ALS) data and field surveys in a 1067-hectare forested area. A digital elevation model (DEM) was generated from ALS data, which was then used to derive additional layers such as slope, aspect, topographic position index (TPI), and landforms. The authors developed a mathematical procedure to determine the radii for the topographic position index. The canopy height model was created, and individual trees were segmented using a novel voxel aggregation method, allowing for the calculation of tree height and crown size. Accuracy assessments were conducted between ALS-derived data and field-collected data. Terrain variability within each forest unit was evaluated using characteristics such as standard deviation, entropy, and frequency. The relationships between tree height and the derived topographic features within forest subcompartments, as well as the correlation between the height yield map for the entire area and the TPI layer, were analysed. The authors found strong correlation between the topographic position index and tree heights in both cases. The presented remote-sensing-based methodology and the results can be effectively used in digital forest site mapping, complemented by field sampling and laboratory soil analyses, and, as final goal, in carbon stock assessment.

Assessment of Phytomass and Carbon Stock in the Ecosystems of the Central Forest Steppe of the East European Plain: Integrated Approach of Terrestrial Environmental Monitoring and Remote Sensing with Unmanned Aerial Vehicles.

The rapid and accurate estimation of aboveground forest phytomass remains a challenging research task. In general, methods for estimating phytomass fall mainly into the category of field measurements performed by ground-based methods, but approaches based on remote sensing and ecological modelling have been increasingly applied. The aim is to develop the scientific and methodological framework for the remote sensing estimation of qualitative and quantitative characteristics of forest stands, using the combination of surveys and machine learning models to determine phytomass of forest stands and calculate the carbon balance. Even-aged stands of different tree species growing in the forest steppe zone of the East European Plain were chosen as test objects. We have applied the modernized methodological approaches to compare and integrate forest and tree stand characteristics obtained by ground-based and UAV-based comprehensive surveys; additionally, we developed computer vision models and methods for determining the same characteristics by remote sensing methods. The key advantage of the proposed methodology for remote monitoring and carbon balance control over existing analogues is the minimization of the amount of groundwork and, consequently, the reduction inlabor costs without loss of information quality. Reliable data on phytomass volumes will allow for operational control of the forest carbon storage, which is essential for decision-making processes. This is important for the environmental monitoring of forests and green spaces of various economic categories. The proposed methodology is necessary for the monitoring and control of ecological-climatic and anthropogenic-technogenic transformations in various landscapes. The development is useful for organizing the management of ecosystems, environmental protection, and managing the recreational and economic resources of landscapes with natural forests and forest plantations.

Multi-dimensional temperature sensitivity of protected tropical mountain rain forests

IntroductionTropical mountain rain forests (TMRF, natural forests at > 300 m asl) are globally important for biodiversity and ecosystem services and are believed to be highly vulnerable to climate change. But there are no specific approaches for rigorous assessment of their vulnerability at the landscape and local scales necessary for management for adaptation. We address the challenge of evaluating the ecological sensitivity to temperature of TMRF, applying a multidimensional approach in protected areas over a 440–2,950 m asl altitudinal gradient in Costa Rica, synthesizing results of a long-term research programme (2012-present). We evaluate the sensitivity to the current spatial temperature gradient of eleven ecosystem properties in three categories: forest composition and diversity, thermal characteristics of forest stands and forest structure and dynamics.MethodsData are from 29 to 32 plots of 50 m x 50 m (0.25 ha) distributed over the gradient, in which all trees, palms and tree ferns ≥ 10 dbh are identified to species and measured for recruitment, growth and mortality. An experimental study of leaf litter decomposition rates was carried out in twelve plots. Current and future (SSP 585, 2070) values of mean annual temperatures MAT were obtained from online climate surfaces. Thermal characteristics of forest stands were determined using MATs of species occurrences in GBIF and include a new index, the Community Thermal Capital Index (CTCI), calculated as CTI-MAT.ResultsWe classified degrees of sensitivity to temperature as very weak, weak, moderate or substantial. All eleven ecosystem properties are substantially sensitive, so changes in their values are expected under rising temperatures. Species density, the community temperature index CTI, tree recruitment and mortality rates and leaf litter decomposition rates are positively related to temperature, while the community weighted mean thermal niche breadth, the CTCI, net basal area increments, stand basal area and carbon in aboveground biomass are negatively related. Results point to zones of vulnerability in the protected areas.DiscussionIn montane forests, positive values of the CTCI–climate credit– robust basal area growth and very low mortality and leaf litter decomposition rates suggest healthy ecosystems and no risk of mountaintop extinction. Lowland forests may be vulnerable to degradation and biotic attrition, showing current basal area loss, high mortality and climate debts. National and local actors are participating in a process of adoption of the sensitivity analysis and recommendations regarding zones of vulnerability.

Modeling Management-Relevant Urban Forest Stand Characteristics to Optimize Carbon Storage and Sequestration

Urban forests are an essential part of adaptation and mitigation solutions for climate change. To understand the relationship between carbon storage, sequestration, and stand density in the most heavily-managed aspect of the urban forest—street trees—we modified the parameters and algorithms of a rural forest dynamics model, the perfect plasticity approximation (PPA), to reflect urban street tree conditions. The main changes in the new street tree PPA are the maintenance of a prescribed stand density via management of recruitment, the possibility of crown-roof overlap, and increased mortality rates. Using the street tree PPA, we explored overall productivity, crown allometry relative to stem diameter, and mortality rate to test each mechanism’s impact on urban street tree carbon storage and sequestration across a gradient of prescribed stand density, with the goal of finding conditions in which street tree carbon storage and sequestration are optimized. We compared the qualitative trends in storage from the street tree PPA to those found in the U.S. Forest Service’s Urban Forest Inventory Analysis data. We found that carbon storage and sequestration increase with prescribed density up to a point where carbon storage and sequestration saturate. Optimized carbon storage and sequestration result from a stand with high productivity, maximized crown allometry relative to stem diameter, and a low mortality rate. These insights can be used to inform urban street tree maintenance strategies that effectively increase carbon storage and sequestration within a given city, such as focusing afforestation campaigns on adequate areas with the lowest street tree densities.

Methodology for determining the suitability of soils for afforestation in plain part of Ukraine

Purpose. To develop a methodology for assessing forest suitability for certain varieties of unproductive soils. Methods. There are used the classical methods of soil science, agrochemistry, forest science, forest management, typology and mathematical statistics. Results. The principles of forest typology are the basis for determining the suitability of soils for forestation. Its essence lies in a comprehensive study of soil properties (soil morphometry, chemical composition) and forestry characteristics of forest stands, as well as an analysis of the grass-shrub layer by ecomorphs. The results of studies of the combined study of the productivity of forest stands and the properties of the main varieties of unproductive soils (sandy, eroded and skeletal) in different natural zones of the plain part of Ukraine are presented. Determination of the suitability of soils for forestation was assessed according to three categories: 1) unsuitable for forestation and conditionally suitable for forestation (very dry, very poor, toxic, with a limited rhizosphere zone, inaccessible or hardly accessible for cultivation); 2) limited suitability for forestation (dry and poor soils); 3) suitable for forestation. Packages of markers have been developed, on the basis of which it is possible to assess both their forest suitability and determine the type of forest growth conditions of non-forest lands. When compiling markers, preference was given to such soil indicators, which, along with informativeness in relation to soil quality, did not require complex methods of determination. The composition of markers includes morphological, physical, agrochemical parameters and depends on the type of soil. Conclusions. The developed packages of markers are the basis for the scientifically based creation of forests on unproductive lands, on which forest vegetation did not grow before. Their use in afforestation increases its efficiency and makes forests more resistant to adverse environmental factors. The Methodology is intended for forestry specialists, it can be used at enterprises, institutions of the forest sector, forest design organizations, as well as in related industries concerned with the protection and rational use of natural resources. The methodological developments can be included in the curricula of secondary and higher forestry-oriented education institutions.

GIS-based planning of buffer zones for protection of boreal streams and their riparian forests

Forested buffer zones with varying width have been suggested as the most promising approach for protecting boreal riparian biodiversity, reducing erosion, and minimizing nutrient leaching from managed forestry areas. Yet, less optimal fixed-width approach is still largely used, likely because of its simple design and implementation. We examined the efficiency of varying-width buffer zones based on depth-to-water (DTW) index in protecting stream riparian plant communities. We further compared the economic costs of DTW-based buffer to commonly used 5, 10 and 15 m fixed-width buffers. We also included an additional buffer based on a combination of DTW and erosion risk (Revised Universal Soil Loss Equation, RUSLE) into these comparisons to see the extent and cost of a buffer that should maximize the protection of the linked aquatic environment. Plant species richness increased with increasing soil moisture and species preferring moist conditions, nutrient-rich soils and high pH were clearly more abundant adjacent to stream in areas with high predicted soil moisture than in dry areas. Differences in species richness were paralleled by differences in community composition and higher beta diversity of plant communities in wet than in dry riparian areas. There were also several indicator species typical for moist and nutrient-rich soils for wet riparian areas. Riparian buffer zones based on DTW were on average larger than 15 m wide fixed-width buffers. However, the cost for DTW-based buffer was lower than for fixed-width buffer zones when the cost was normalized by area. Simulated selective cutting decreased the costs, but cutting possibilities were variable among streams and depended on the characteristics of forest stands. Our results thus suggest a high potential of DTW in predicting wet areas and variable-width buffer zones based on these areas in the protection of riparian biodiversity and stream ecosystems.

Microclimatic conditions mediate the effect of deadwood and forest characteristics on a threatened beetle species, Tragosoma depsarium

While climate change has increased the interest in the influence of microclimate on many organisms, species inhabiting deadwood have rarely been studied. Here, we explore how characteristics of forest stands and deadwood affect microclimate inside deadwood, and analyse how this affects wood-living organisms, exemplified by the red-listed beetle Tragosoma depsarium. Deadwood and forest variables explained much of the variation in temperature, but less of the variation in moisture within deadwood. Several variables known to influence habitat quality for deadwood-dependent species were found to correlate with microclimate. Standing deadwood and an open canopy generates warmer conditions in comparison to downed logs and a closed canopy, and shaded, downed and large-diameter wood have higher moisture and more stable daily temperatures than sun-exposed, standing, and small-diameter wood. T. depsarium occupancy and abundance increased with colder and more stable winter temperatures, and with higher spring temperatures. Consistently, the species occurred more frequently in deadwood items with characteristics associated with these conditions, i.e. downed large-diameter logs occurring in open conditions. Conclusively, microclimatic conditions were found to be important for a deadwood-dependent insect, and related to characteristics of both forest stands and deadwood items. Since microclimate is also affected by macroclimatic conditions, we expect species’ habitat requirements to vary locally and regionally, and to change due to climate warming. Although many saproxylic species preferring sun-exposed conditions would benefit from a warmer climate per se, changes in species interactions and land use may still result in negative net effects of climate warming.

Is Douglas Fir [Pseudotsuga menziesii (Mirbel) Franco] Invasive in Central Europe? A Case Study From South-West Germany

Worldwide, forestry must face several challenges during the UN Decade on Ecosystem Restoration. The decline of biodiversity and ecosystem services, ongoing deforestation, climate change, and biological invasions must be mitigated with forest restoration and by applying sustainable forest management. Experiences with the integration of non-native tree species into forest management in many parts of the world show benefits but also trade-offs regarding sustainability. In Central Europe, Douglas fir [Pseudotsuga menziesii (Mirbel) Franco], originating from Northern America, has been introduced by forestry and managed for more than one and a half centuries. Growth characteristics, drought tolerance, and timber quality are major reasons which make this tree species attractive for forestry and wood industry. Whether Douglas fir might be invasive with potential trade-offs regarding biodiversity, uncontrolled regeneration, and spread is not yet fully understood and controversially debated. We investigated the regeneration of Douglas fir in the Spessart mountains, a vast woodland in south-western Germany which has a considerable cover of anthropogenic coniferous afforestations. We sampled the regeneration of Douglas fir by differentiating height growth classes in various forest-stand types, taking the distance from mature mother trees, abiotic site conditions (e.g., water balance and soil properties), light supply, forest-stand characteristics, ground vegetation, and browsing pressure into account. Also integrating the individual regeneration of the accompanying tree species, we applied multivariate analyses. Most of our investigated variables did not show a significant correlation with Douglas fir regeneration. However, results point to a positive relationship of spontaneous Douglas fir regeneration at moist and light sites as well as in close distance to potential seed trees. The analysis of the current invasion potential did not reveal a major risk under the given site conditions in the study area.

Состояние еловых насаждений в районе южнотаежных лесов таежной зоны в Удмуртской Республике

The study results of coniferous stands and the description of stands in the southern taiga forests of the taiga zone within the Udmurt Republic (on the territory of the Yakshur-Bodya, Igrinsky and Kez forest districts) are presented. The climatic indicators of the study year are presented in comparison with the average long-term data for the studied areas. The taxational characteristics of forest stands are given, the indicators of the morphological profile, humidity, and cellulose-decomposing activity of forest litter are presented. Studies have shown that the cellulose-decomposing activity of forest litter depends on its moisture content, which is associated with the values of the basal area per hectar of stands in the studied sample areas. No differences in the indicator of cellulose-decomposing activity were found in the sample areas in the Igrinsky forestry. The highest values of this indicator were determined in the sample area No. 1 in the Kez forestry. The lowest values of the cellulose-decomposing activity of forest litter were observed in the sample areas No. 1 and No. 3 in the Yakshur-Bodya forest area. The physiological and biochemical parameters of Siberian spruce (Pícea obováta Ledeb.) were analyzed and compared in trees of good and satisfactory living conditions, which did not show statistically significant differences in the content of chlorophylls and carotenoids in the needles. A significantly high content of photosynthetic pigments and tannins in Siberian spruce conifers was found in the sample areas in the Igrinsky forest area. Similar results were obtained for individuals of a satisfactory living condition, with the exception of the content of tannins in conifers. It was found that the high content of chlorophyll a in Siberian spruce needles is usually accompanied by an increased content of tannins and a low concentration of ascorbic acid. It is shown that in general, the potential of Siberian spruce individuals associated with the biochemical level of the formation of adaptive reactions is highest in plants in the northern regions of the republic, i.e. in areas with more extreme growing conditions. Materials were obtained on the basis of which it is possible to develop a program for monitoring plantings and restoring forest stands.

Floodplain Large Wood and Organic Matter Jam Formation After a Large Flood: Investigating the Influence of Floodplain Forest Stand Characteristics and River Corridor Morphology

AbstractThe controls on large wood (LW; wood >1 m in length and >0.1 m in diameter) and coarse particulate organic matter (CPOM; organic material >1 mm in diameter) deposition on floodplains have rarely been assessed, and there are few studies that explore the bidirectional interactions between wood, standing trees, and geomorphic processes. We use field data from West Creek, Colorado, USA, to assess the influence of river corridor morphology and forest stand density on the depositional patterns of floodplain LW and CPOM accumulations (jams) resulting from an extreme flood. Relatively high LW loads per area (mean ± SE = 678.6 ± 192.3 m3 ha−1) point to the importance of extreme floods for LW deposition on floodplains. We find that LW jams decreased in size with distance from and elevation above the channel, but that CPOM jams did not, demonstrating that the relatively smaller CPOM can be more easily transported within a forested floodplain. Steeper reaches contained smaller LW and CPOM loads per area, which may indicate that reaches with higher stream power during the flood were less depositional. As forest stand density increased, the number of CPOM jams per area increased, and a majority of jams were pinned by standing trees. Trees were trapping locations for LW and CPOM, highlighting the importance of preserving riparian forests. Floodplain LW and CPOM provide habitat and nutrients to floodplain ecosystems and influence geomorphic processes, creating an opportunity to use LW in restoration while reducing potential hazards caused by in‐channel LW.

Site index research: a literature review

Abstract The purpose of this paper was to review literature covering the topic of site index with particular emphasis on Scots pine, the most important forest-forming species in Poland. We discuss the history of the site index, research on various tree species, statistical modelling methods, the spatial application of site index and age impact assessment. The history of research on the site index of forest species is long and dates back to the 18th century. Many researchers thought that determining the quality of the habitat is very important from the point of view of rational forest management. The site index, as a measure of the potential of the habitat on which the forest grows, is one of the most important characteristics of forest stands. The site index depends on the selected model, but is most often expressed as the average or top height of trees of a given species at a certain age. In our review, we point out several insufficiencies of studies on the site index, external influences and the connection of the site index with spatial conditions. Furthermore, research conducted so far has not explicitly confirmed that there is a relationship between the site index of pine stands and their geographical location in Poland. More research on the site index, especially in regard with climate change, is needed.

Examining LiDAR – WorldView-3 data synergy to generate a detailed stand map in a mixed forest in the north-west of Turkey

Although stand delineation approach based on aerial photographs and field survey produces high accuracy maps, it is labour-intensive and time consuming. Furthermore, conventional forest stand maps may have some uncertainties that can hardly be verified due to the experiments and skills of photo-interpreters. Therefore, researchers have been seeking more objective and cost-effective methods for forest mapping. LiDAR (Light Detection and Ranging) data have a high potential to automatically delineate forest stands. Unlike optical sensors, LiDAR height data provides information about both the horizontal and vertical structural characteristics of forest stands. However, it deprives of spectral data that may be successfully used in separating tree species. In this study, we investigate the potential of LiDAR – WorldView-3 data synergy for the automatic generation of a detailed forest stand map which can be used for a tactical forest management plan. Firstly, image segmentation was applied to LiDAR data alone and LiDAR/WorldView-3 data set in order to obtain the most suitable image objects representing forest stands. Visual inspection of the segmentation results showed that image objects based on the LiDAR/WorldView-3 data set were more compatible with the reference forest stand boundaries. After the segmentation process, the LiDAR and LiDAR/WorldView-3 data sets were independently classified using object-based classification method. We tested two levels of classification. The first was a detailed classification with 14 classes considering reference stand types. The second was the rough classification with 9 classes where some stand types were combined. The mean, standard deviation and texture features of LiDAR metrics and spectral information were used in the classification. The accuracy assessment results of LiDAR data showed that the Overall Accuracy (OA) was calculated as 0.31 and 0.43, and the Kappa Index (KIA) was calculated as 0.26 and 0.32 for the detailed and rough classifications, respectively. For the LiDAR/WorldView-3 data set, the OA values were calculated as 0.50 and 0.61, and the KIA were calculated as 0.46 and 0.55 for the detailed and rough classifications, respectively. These results showed that the forest stand map derived from the LiDAR/WorldView-3 data synergy is more compatible with the reference forest stand map. In conclusion, it can be said that the forest stand maps produced in this study may provide strategic forest planning needs, but it is not sufficient for tactical forest management plans.

Estimation of Semiarid Forest Canopy Cover Using Optimal Field Sampling and Satellite Data with Machine Learning Algorithms

Forest canopy cover represents different characteristics of forest stands. However, especially in semiarid forest, the estimation of canopy cover by field measurements is too expensive. Therefore, it is necessary to develop appropriate techniques to estimate forest canopy cover for forest management in semiarid areas. In this research, a robust procedure to estimate canopy cover using stratification field sampling and AdaBoostM1 machine learning algorithm with Landsat 8 OLI imagery is suggested. Approximately 29,000 ha of semiarid forest (Manesht- and Ghelarang-protected area) in west of Iran was selected as the study area. The unsupervised classification was used on NDVI layer extracted from OLI data, and Neyman method was applied for allocation, in stratified areas. The crown cover was measured in percentage in each plot. In inaccessible plots, the optical satellite imagery of Worldview-2 from Google Earth database was used (0.46 m spatial resolution). For the classification of canopy cover, the AdaBoostM1 algorithm with random forest classifier was trained by 75% split original data, while 25% remaining data were used for accuracy assessment using ROC curve, true positive (TP), false positive (FP), overall accuracy (OA) and kappa coefficient (K). The results showed the overall accuracy and kappa coefficient of 91% and 0.88, respectively. Based on the results, the methodology developed in this study is suitable to estimate canopy cover in semiarid forests.

A Study on the Distribution and Dynamics of Relict Forest Trees and Structural Characteristics of Forest Stands in Gangwon Province, Korea

A Study on the Distribution and Dynamics of Relict Forest Trees and Structural Characteristics of Forest Stands in Gangwon Province, Korea

Predicting Selected Forest Stand Characteristics with Multispectral ALS Data

In this study, the potential of multispectral airborne laser scanner (ALS) data to model and predict some forest characteristics was explored. Four complementary characteristics were considered, namely, aboveground biomass per hectare, Gini coefficient of the diameters at breast height, Shannon diversity index of the tree species, and the number of trees per hectare. Multispectral ALS data were acquired with an Optech Titan sensor, which consists of three scanners, called channels, working in three wavelengths (532 nm, 1064 nm, and 1550 nm). Standard ALS data acquired with a Leica ALS70 system were used as a reference. The study area is located in Southern Norway, in a forest composed of Scots pine, Norway spruce, and broadleaf species. ALS metrics were extracted for each plot from both elevation and intensity values of the ALS points acquired with both sensors, and for all three channels of the ALS multispectral sensor. Regression models were constructed using different combinations of metrics. The results showed that all four characteristics can be accurately predicted with both sensors (the best R2 being greater than 0.8), but the models based on the multispectral ALS data provide more accurate results. There were differences regarding the contribution of the three channels of the multispectral ALS. The models based on the data of the 532 nm channel seemed to be the least accurate.

Prediction of the appearance of tree of heaven in forest communities in western Slovenia

Background and Purpose: Tree of heaven (Ailanthus altissima) is one of the most invasive tree species in Slovenia. Since its invasion into forests is expected, we must raise public awareness and prepare guidelines for forest management in the presence of invasive species. The aim of the research was to predict the potential distribution of tree of heaven, to detect the most endangered forest communities and to discover what characteristics of forest stands make them susceptible.Materials and methods: From databases, literature sources and field observations, we collected all localities in which tree of heaven appears. We assigned these localities geological, geomorphological, soil and climatic data. We then built an ecological model and prepared a map of potential distribution. Based on the modelled future distribution of tree of heaven, we randomly selected and sampled 50 plots in the area in which invasion is expected and beyond this area. We analyzed their morphological and ecological strategies, ecological condition, origin and social behavior spectrum.Results: We found that it has the largest invasive potential in western Slovenia. The model showed that the most susceptible forest communities appear in warm areas with pronounced climatic seasonality. Many differences occur in floristics and plant traits of forest communities in extreme positions, in terms of susceptibility to invasion, but in transitional areas, these differences are not so obvious, only a higher pH of soil and absence of species characteristic of acidophilus communities are an indicator of vulnerability.Conclusion: Susceptibility to invasion by tree of heaven is mainly influenced by macro-climatic conditions; in the transitional zone, communities thriving on shallow, carbonate bedrock are more vulnerable.

Selection priority for harvested trees according to stand structural indices

The selection of trees to be harvested is a core tenet of uneven-aged forest management; however, few studies have focused on the process of tree selection. A set of stand structural parameters (uniform angle index, W; mingling index, M; dominance index, U) based on tree neighbor-spatial relationships, are particularly suitable for expressing the structural characteristics of forest stands. Such indices were used to parameterize thinning in three plots (a-c, each 100 × 100 m2) in a Korean pine broad-leaved forest in northeastern China and one plot (h, 70 × 70 m2) in a pine-oak mixed forest in northwest China. Low-intensity single-tree selection was applied according to the principles of structure-based forest management (SBFM), i.e., to promote high mixture, obvious size differentiation, and random pattern with the aim of improving the overall structure of the managed plots. A group of thinning priority indices (v_ij, k_ij and z_ij) were calculated according to the bivariate distributions of the structural characteristics of harvested trees and stands before harvest. Our results demonstrated that v_ij, k_ij and z_ij adequately describe the spatial relationship between each tree and its nearest neighbors, and their combinations can be efficiently used to set thinning priorities on harvested trees with different structural characteristics. Their application can reduce the subjectivity of the selection process and improve the speed and accuracy of the choice of trees to be harvested in uneven-aged mixed forests.

Relationships among burn severity, forest canopy structure and bat activity from spring burns in oak–hickory forests

The extent to which prescribed fires affect forest structure and habitats of vertebrate species is an important question for land managers tasked with balancing potentially conflicting objectives of vegetation and wildlife management. Many insectivorous bats forage for insect prey in forested habitats, serving as the primary predators of nocturnal forest insects, and are potentially affected by structural changes in forests resulting from prescribed fires. We compared forest-stand characteristics of temperate oak–hickory forests, as measured with airborne laser scanning (light detection and ranging, LiDAR), with categorical estimates of burn severity from prescribed fires as derived from Landsat data and field-based Composite Burn Indices, and used acoustic monitoring to quantify activity of insectivorous bats in association with varying degrees of burn severity (unburned habitat, low severity and medium severity). Forest-stand characteristics showed greatest separation between low-severity and medium-severity classes, with gap index, i.e. open-air space, increasing with degree of burn severity. Greater mid-storey density, over-storey density and proportion of vegetation in the understorey occurred in unburned habitat. Activity of bats did not differ with burn severity for high-frequency (clutter-adapted or closed-space foragers) or low-frequency (edge or open-space foragers) bats. Results indicate that differing degrees of burn severity from prescribed fires produced spatial variation in canopy structure within stands; however, bats demonstrated no shifts in activity levels to this variation in canopy structure, suggesting prescribed fire during the dormant season, used as a management practice targeting desired changes in vegetation, is compatible with sustaining foraging habitat of insectivorous bats.

Radar Data for Identifying the Characteristics of Tropical Forest Stands

Radar is one of remote sensing technology which utilizes active electromagnetic energy and are able to provide information about the characteristics of forest stand. This study utilized JERS-1 and ERS-1 radar images to analyze the relationship between the radar backscatter and forest stand characteristics such as Diameter Breast Height (DBH), basal area, and canopy cover. This research was conducted in Jambi Province, Bungo Tebo District, Sumatra, Indonesia. The research site covered the forest concession, Suku Anak Dalam, the area adjacent to Pelepat and Batang Tebo River, and Kuamang Kuning village. Gamma Map Filter with 7 x 7 window size was applied to reduce speckle noise of the SAR images (ERS-1 and JERS-1). This study found out the positive significant correlation between basal area and DBH with JERS-1 radar backscatter (i.e., r = 0.75 and r = 0.70), while ERS-1 radar backscatter has correlation (r = 0.64) with the canopy cover.

Новые методы в оценке качественных и количественных характеристик лесных насаждений

Новые методы в оценке качественных и количественных характеристик лесных насаждений