Structural Characteristics Of Forest Research Articles

Quantifying old-growth forest of United States Forest Service public lands

Old-growth forests are globally valued for their ecological attributes, cultural significance, and in many cases their rarity. Yet, defining and quantifying these forests has been a difficult task. This study developed an approach to consistently estimate extent of old-growth forest on United States Department of Agriculture (USDA) Forest Service National Forest System (NFS) lands, using NFS regional old-growth definitions applied to the US national forest inventory (conducted by the USDA Forest Service Forest Inventory and Analysis [FIA] program). This method was developed in response to a presidential order (EO#14072, April 22, 2022) and federal laws (e.g., Infrastructure Investment and Jobs Act, 2021; Inflation Reduction Act, 2022). We worked with NFS experts to obtain regionally approved criteria for establishing old growth status based on NFS definitions, assessments, and related documents. NFS regional old growth definitions focus on structural characteristics of forests with criteria for old growth status commonly including minimum abundance of large live trees (in eight of nine regions), tree or stand age (in eight of nine regions), and dead large tree density (in three of nine regions). Determining the regional criteria to use was straightforward for some NFS regions where old-growth forest definitions were specific, and in some cases, had already been applied to FIA data to quantify old-growth forest area. In other NFS regions, such as where definitions have never been applied in an operational manner, or where there were merely assessments of remnant old-growth forest conditions, determining exact criteria was more difficult. We estimate that there are approximately 10 million ha of old growth across NFS forests, as defined by NFS criteria, with the preponderance in the western US states. This study produces the first old-growth forest assessment at the national scale based on NFS definitions and FIA’s statistically-rigorous national forest inventory of the US. These methods can be repeated with future inventories or modified when definitions change to produce updated estimates of old-growth forest attributes, and such work is already underway.

Silviculture in the function of sustainable development

Silviculture in the function of sustainable development

A Technique to Evaluate Agricultural Landscape Changes on the Basis of GIS-Processed 1861 Demarcation Plans and Current Description of Kenozero National Park

In many Russian nature reserves traditional landscapes are objects of important historical and cultural heritage. To preserve and restore them one needs to deeply understand their development, formation and degradation processes. In the north of European Russia agricultural landscapes are often covered with forests and lose their features when agricultural activity decreases. However, structural characteristics of these forests as a rule tell us about their development and peculiarities of successions. The study aims at creating a technique to estimate the scope of former agricultural land development, model historical transformation of agricultural landscapes and identify plots of slash and burn, shifting, two and three field agriculture judging by structural characteristics of post-agrarian forests. Aided by GIS the study compares raster analogs of land demarcation plans of the second half of the 19th century and vector layers of present day forests with attributive data on the forest structure. The use of cartographic forest data and inventory forest characteristics to compare with former land management documents related to the plot named have not been found in studies before. High precision of present day land management provides for permitted comparability with old demarcation plans and allows one to use inventory data for inter-landscape differentiation of agricultural landscapes in the 19th century. The study covers a model plot within Kenozero National Park (Arkhangelsk Region) addressing 1861 demarcation plans and 2014 forests GIS developed by Arkhangelsk branch of Roslesinforg. GIS processing of 19th century and present day demarcation plans provides for modeling agricultural landscape changes in relation to separate plots, trace the influence of soil conditions and elements of agrarian use on topological and inventory changes of emerging forests and reconstruct the biodiversity of ecosystems in the past.

Structural characteristics of the mixed spruce - fir - beech forests on Mountain Bjelasica in Montenegro

Biogradska Gora National Park in Montenegro is part of the Bjelasica Mountain which belongs to the montane region of the Dinaric Alps. Biogradska Gora is one of the largest long-term preserved forests in the Southeast Europe. In this paper there were compared the main structural characteristics of the old-growth mixed forest of spruce (Picea abies L.), fir (Abies alba L.) and beech (Fagus moesiaca (Domin, Maly) Czecz.), from the preserved area of the Biogradska Gora, with similar managed forests from the same mountain. Basic insight into the structural characteristics of forests of spruce, fir and beech was obtained by analyzing tree species composition and two basic structural elements - number of trees and wood volume per unit area. The obtained data provides overview of the structural characteristics of these forests. The results revealed the production potential of the studied mixed forests. The average quantity of standing volume in old-growth forests of Biogradska Gora indicates very valuable and productive forest ecosystems. Presented data shows that forest ecosystems of spruce, fir and beech in the protected area of the National Park Biogradska Gora are characterized by structurally irregular forests with presence of old trees with relevant growing stock and optimal balance of beech and conifer species, while in managed forests on the same mountain, growing stock is very low and with structure which is far from optimal.

Forest community survey and the structural characteristics of forests in China

Most of the world’s terrestrial biome types can be found in China. To systematically investigate species composition and structure of China’s forest communities, we launched a long‐term project consisting forest vegetation surveys across China’s mountains in the mid 1990s. Over the study period, we have conducted vegetation surveys for 65 mountains and collected vegetation data from about 1500 forest plots, using consistent sampling protocols. In this paper we first introduce the aims, protocols, and major research themes of the project, and then describe the major characteristics of forest communities and their geographic patterns and climatic controls. As latitude increased, diameter at breast height (DBH) and height of trees increased, while individual density of trees and woody species richness decreased. Total basal area (TBA) of trees and species richness of herbs did not vary with latitude. Contemporary climate seems to drive these patterns: temperature was the leading factor for DBH, precipitation was most important for tree height and individual density, actual evapotranspiration (a surrogate of productivity) determined woody (trees and shrubs) species richness, and rainfall was the major controller of the herb species richness. The species–abundance relationship showed that species dominance (measured by the number of individuals per species) declined significantly from boreal forests to evergreen broadleaf forests from north to south. Our results are in line with the idea that productivity drives woody species richness. Similarly, we find that biomass (measured as TBA) is invariant along the environmental gradients. However, individual density varies dramatically, in contrast to the assumptions underlying the metabolic theory of ecology.

Extraction of Features From LIDAR Waveform Data for Characterizing Forest Structure

Determination of structural characteristics of forests at large scales is an important problem in both scientific studies and development of management practices. Light detection and ranging (LIDAR) waveform data have been demonstrated to be valuable for estimating forest structural parameters even in dense forests, although challenges inherent to the LIDAR acquisition systems must be addressed. A new approach for processing LIDAR waveform data to estimate forest structural parameters is proposed. It was applied to Laser Vegetation Imaging Sensor waveform data acquired over old-growth tropical forest in the La Selva Biological Station, Costa Rica. Linear and nonlinear feature extraction methods were utilized to derive a lower dimensional feature space from high-dimensional LIDAR waveform data. The resulting features were used to estimate mean canopy heights through multiple linear regression analysis. Experimental results obtained by the new approach were statistically comparable to estimates obtained using features extracted via traditional waveform analysis, and the proposed approach successfully discovered another meaningful lower dimensional feature space without manual interpretation.

Capercaillie (<em>Tetrao urogallus</em> L.) habitats in managed Finnish forests – the current status, threats and possibilities

The aim of this study was to provide applicable knowledge for taking capercaillie into consideration in forest management and thus progress ecologically sustainable forestry. Capercaillie is a respected game species, but it also has indicator and umbrella species characteristics. Therefore capercaillie is closely linked to many other species. The study focused on the question: which structural characteristics of forest are important for the capercaillie? To gain a thorough view of capercaillie habitat needs, various capercaillie habitats were studied at several spatial scales in Finland in 1990s and 2000s. Species data were mostly from the wildlife monitoring counts. Forest planning data from Metsahallitus and data from the national forest inventories formed the landscape data. At large spatial scale (2500 km study units) the capercaillie population density was positively associated with the proportion of young thinning stands throughout the country. The association between capercaillie and young thinning stands was also positive at smaller scales in summer habitats, winter habitats and lek surroundings in northern Finland, where also the stand density was found to be positively associated with capercaillie in the summer habitats. The positive relationship between capercaillie and mature forests was found at the beginning of 1990s, but later this association was weak. The managed boreal forests become suitable for the capercaillie within 30 – 40 years, and so the large areas clear-cut in 1950s and 1960s in Finland became suitable for the capercaillie mostly in the 1990s. But the habitat quality may also decrease in the later successional stages of forest. The shortterm effects of thinnings on the capercaillie microhabitat quality can vary depending on the stand characteristics and season, and between adult birds and broods, but in the long term low cover on the ground may be the factor, which reduces the habitat quality in older managed forests especially in the low-productive areas and sites. Overall forest cover at the landscape scale, canopy cover and cover on the ground are important forest characteristics for the capercaillie. Longer rotations, understorey management and selective cuts are suitable methods to increase the capercaillie habitat availability and quality in the managed Finnish forests. Capercaillie habitat management calls also for spatial planning and preserving the availability of pine specifically in southern Finland. Also the costs and benefits of cutting residue management and possibilities to reduce the ditch restoration intensity in peatland forest management deserve a careful evaluation in the future. Furthermore, the connections between the abovementioned forest characteristics and other species deserve also to be studied.

Rainfall Interception by a Forest Canopy

It was found that the phenomenon of rainfall interception by a forest stand can be expressed by Mitscherlich equation (3). Using the data observed in a deciduous stand in Bialowieza (Poland) they have approximately determined the values of the coefficients of this equation (3 a). Consequently they expressed the amount of the rainfall inside the forest (R0) as a function of rainfall in the open (4, 4 a). The validity of the conception is presented by a graph (Fig. 2). As the purpose of this sort of investigations is to determine of ecological relationships between structural characteristics of forest stands and their interception capacity, the writers have sketched the relationship between the interception and stand height, basal area of trees and number of trees per area unit (the formula 10). This frame relationship was confirmed by the empirical data after Kittredge (Tab. 2). PeNioMe ABTopbI HaxOAXT, 'ITO HBBJIeHHCe 3aAepXKaHIP AoxnAi ApeBocToeM Bbipa)KaeTc A ypaBHeHHeM MHiVepn1Hxa (4opysyna 3), rAe: