Semicentennial dynamics of old silver birch (Betula pendula Roth) forests in the Belavezhskaya Pushcha National Park

It was investigated the dendroflora’s species composition of green plantations of Karlivka town (Poltava region), including intraurban group consisting of planting sites located within the area of residential and industrial neighborhoods – three parks, square, street and roadside green spaces and planting in the industrial enterprises, schools and kindergartens. It was revealed the eco-valeological role of dendroflora in optimizing the environment of the studied town. As part of the green space of Karlivka town it was isolated the groups of rocks for their functional purpose: dust-adsorbing (Populus tremula L., Quercus robur L., Tilia cordata Mill., Picea abies L., Betula pendula Roth., Acer platanoides L., Fraxinus excelsior L., Sorbus aucuparia L.); nois- insulating (Populus italica L., Salix fragilis L., Aesculus hippocastanum L., Betula pendula, Fraxinus excelsior, Acer negundo L., A. platanoidеs, Syringa vulgaris L.); microclimatic (Quercus robur, Populus italica, Tilia cordata, Salix fragilis, Picea abies, Robinia pseudoacacia L., Acer platanoides, A. negundo, Betula pendula, Aesculus hippocastanum, Fraxinus excelsior). It was founded, that in green spaces of parks and streets of Karlivka town predominant species are the group that least let the solar radiation (0,8-0,9%), because they have a thick crown – Aesculus hippocastanum, Acer platanoides, Quercus robur, Populus italica, Fraxinus excelsior, Tilia cordata and others; species, which have a disperse crown and able to pass most of the sunlight (7,0-9,0%), are Robinia pseudoacacia, Betula pendula, etc. The study established that when choosing and planting trees and bush, do not always take account of their species and varietal assortment, ecological and decorative properties. Based on the results it was identified the areas that are need for reconstruction of landscape gardening.

Разнообразие широколиственных и сосново-широколиственных лесов на восточной границе их распространения

Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland

The content and mass concentration of eight chemical elements Al, Ca, Cu, K, Mg, Mn, P, and Zn were analysed in dead wood of eight tree species at five stages of decomposition. Wood samples were taken at the site of the mass windfall of 2006 in a multispecies broadleaved forest in the Kaluzhskie Zaseki nature reserve. Deadwood of seven deciduous trees species was studied: maple (Acer platanoides), birch (Betula pendula), common ash (Fraxinus excelsior), common aspen (Populus tremula), English oak (Quercus robur), linden (Tilia cordata), rough elm (Ulmus glabra), as well as one coniferous tree species – Norway spruce (Picea abies). A series of one-way analyses of variance was carried out to assess the influence of the species and the stage of deadwood decomposition (including the zero stage for control samples) on the density, content of elements and their mass concentration. Tree species most clearly differed in the content and mass concentration of Mn, Zn, Mg, Ca, and K: R2 varied from 50 to 23% for the content and from 53 to 19% for the mass concentration of elements of the indicated series. The leaders in the content of these elements were the following species: Mn – maple, birch, spruce, linden; Zn – birch and aspen; Mg – maple, elm; Ca – elm; K – linden, elm. The stages of wood decomposition turned out to be a significant factor of variation for the content of Mn, P, Cu, Zn and Ca: R2 varied from 22 to 16%. During the destruction of wood trunks, a significant increase in the content of these elements occurred. Maintenance of cycles of biophilic elements is more successfully implemented in the presence of deadwood of different species at different stages of decomposition.

Еловые леса Ижорской возвышенности (Ленинградская область): типология и современное состояние

Forest productivity reflects forest growth quality and forms the basis for achieving forest service functions. The relationships between forest productivity and stand structure has been extensively studied, but it is still unclear whether environmental factors affect the relationship and how their relationships vary under the influence of stand type and environmental factors. A fixed monitoring dataset from 972 plots of natural mixed forests (including coniferous, broad-leaved, and coniferous and broad-leaved mixed forests) in Zhejiang Province was used. We analyzed the relationship between stand structure diversity (composition diversity and size differentiation diversity) and productivity in the different forest types and their influencing factors. Species richness, coefficient of the diameter at breast height (DBH) variation, and the DBH Shannonâ€'Wiener index were significantly positively correlated with productivity (P < 0.01). Environmental factors such as terrain and meteorology were associated with stand productivity and structure diversity. Considering the effects of environmental factors and stand density, it was evident that stand density was the primary direct factor influencing coniferous forest productivity ([Formula: see text] = 0.635), and terrain exerted a substantial indirect effect on productivity through stand density ([Formula: see text] = 0.202). In broad-leaved forests, topography ([Formula: see text] = -0.161), size differentiation diversity ([Formula: see text] = -0.519), and stand density ([Formula: see text] = 0.954) were the primary factors influencing productivity, with climate exerting a significant indirect effect via stand density and size differentiation diversity. In coniferous and broad-leaved mixed forests, stand density ([Formula: see text] = 0.862), size differentiation diversity ([Formula: see text] = -0.424), and composition diversity ([Formula: see text] = 0.260) were all significantly correlated with productivity. The effect of structure diversity on productivity in natural broad-leaved mixed forests in Zhejiang Province was modulated by environmental factors and stand density. Our research deepens understandings of the factors driving productivity in natural broad-leaved mixed forests and offers a theoretical foundation for sustainable development.

Defining the allometry of stem and crown diameter of urban trees

Only less than one percent of the territory of Latvia is occupied by broadleaved (trees having relatively wide flat leaves) forests. The aim of the research is to assess forest vegetation in the island of Upursala of Cirišs lake. The data is collected in four forest areas of the island. Totally 12 plots, each with an area of 200 m2 (20 x 20 m) have been created. In each plot, the accounting of growing trees and deadwood is carried out. The vegetation is measured in each forest area - the projective vegetation cover and cover of each plant species by tree, shrub, herb and moss layer are determined. The research founds that the average stock of growing trees on the island of Upursala is 565.8 m3 ha-1. The average amount of dead wood is 108 m3 ha-1, it consists mainly of fallen deadwood. Totally 45 species are listed in the vegetation plots, of which seven are determinants of European broadleaved forests. The largest number of determinant species of European broadleaved forests have been observed in stands with mixed forests (aspen - small-leaved lime – pedunculate oak, aspen – Scots pine - pedunculate oak and Scots pine – Silver birch – aspen). It can be argued that these stands will become the European broadleaved forests in the future.

Objective The objective of this study is to explore the distribution characteristics of non-spatial structure and the correlation between non-spatial structure and productivity of coniferous and broad-leaved mixed forests in Zhejiang Province, so as to provide theoretical basis and technical support for improving forest quality. Method Based on the data of natural coniferous and broad-leaved mixed forest sample plots and sample wood from the consecutive forest resource inventory in 1999, 2004, and 2009, the diameter at breast height(DBH), tree height, volume, and non-spatial structure factors and accumulation per unit area of conifer species were extracted. Patterns of non-spatial structure distribution in each period was modeled to explore characteristics of change. The continuous function method of biomass conversion factor was used to estimate biomass and productivity, and then the partial correlation analysis between non-spatial structure and productivity was performed. Result There existed regular distribution characteristics of forest non-spatial structure factors in different periods. The non-spatial structure factors and productivity showed a positive correlation. From 1999 to 2009, the proportion of coniferous species in the coniferous and broad-leaved mixed forest in Zhejiang Province increased gradually, and the productivity in the first period (1.39 t·hm−2·a−1) was higher than that in the second period (1.15 t·hm−2·a−1). The mean value of DBH, tree height and volume per plant were approximately normal. Conclusion In the management of coniferous and broad-leaved mixed forests, priority should be given to the proportion of coniferous and broad-leaved mixed forest in order to maintain the high productivity of the forest stand. The proportion of species should be kept above 50% and the mixed forests with a low proportion of coniferous species should be artificially intervened. If DBH is lower than 10.00 cm, tending should be strengthened, and if DBH is higher than 12.00 cm, cutting should be carried out in time. The average volume and tree height of per plant should be maintained at 0.040−0.070 m3·plant−1 and 7.00−10.00 m respectively. [Ch, 6 fig. 5 tab. 34 ref.]

We surveyed the forest litter amount at the Lianxiahe watershed in the Three Gorges Reservoir Area and analyzed some hydrological characteristics such as the maximum water-holding capacity and water absorption rate of litter in six types of forests, i.e. the Cupressus funebris forest, the coniferous mixed forest, the coniferous and broad-leaved mixed forest, the broad-leaved forest, the Pinus massoniana forest, the bush forest. Results showed that the litter amount follows the order of the coniferous and broad-leaved mixed forest > the pure C. funebris forest, the P. massoniana forest > the coniferous mixed forest > the broad-leaved forest > the bush forest. The maximal water holding capacity of the undecomposed litter is in the order of the C. funebris forest > the coniferous mixed forest > the bush forest > the coniferous and broad-leaved mixed forest > the broad-leaved forest > the P. massoniana forest. The maximal water-holding capacity of the half-decomposed litter is the P. massoniana forest > the coniferous and broad-leaved mixed forest > the C. funebris forest > the coniferous mixed forest > the broad-leaved forest > the bush forest. In this watershed, the water holding capacity of the litter in the C. funebris forest is the highest, followed by the coniferous mixed forest, coniferous and broad-leaved mixed forest, P. massoniana forest, broad-leaved forest and bush forest. When the soil is covered only by litter, both the maximal rainfall amount and intensity in different forest stands are different if there is no water infiltration and runoff from the ground surface.

Radial increment objectively reflects the quality of the assimilation apparatus of a woody plant. Its features indicate the influence of various anthropogenic, biotic and abiotic factors as well as the stability of the plant under stress. The aim of this study was to survey the long-term dynamics of the radial growth of six tree species: Betula pendula, Ulmus glabra, Quercus robur, Tilia cordata, Picea abies and Pinus silvestris, depending on the impact of creating a reservoir and the fluctuations of the water level in it. Additionally, another aim was to determine whether there is a dependence between the annual radial increment of these tree species and the change in the temperature factor during the growing season. We studied cores of trees growing in a park on the coast of the Sheksna river, the level of which is regulated by the water level in the Rybinsk Reservoir and changes along with it. This research presents the dynamics of the annual radial growth of Betula pendula over 59 years, Ulmus glabra over 50 years, Quercus robur over 59 years, Tilia cordata over 82 years, Picea abies over 128 years and Pinus silvestris over 125 years. The average annual radial growth decreases in the series Ulmus glabra &gt; Betula pendula, Quercus robur &gt; Tilia cordata &gt; Picea abies &gt; Pinus silvestris. The radial increase does not correlate with the annual water level in the Rybinsk Reservoir. However, years with extreme minimum and maximum reservoir filling affect the radial growth of Quercus robur (r = 0.56) and Tilia cordata (r = 0.52). It was found that after the creation of the reservoir, the radial increment of Picea abies was significantly reduced by 1.10 mm. The clearest dependence of ring width index was obtained for Picea abies on temperature in May (r = −0.30 at p ≤ 0.05) and for Pinus sylvestris on temperature in July (r = −0.25 at p ≤ 0.05). Similarly, a weak correlation of ring width index with temperature in some months was noted for deciduous trees. Picea abies is notable for its particular display of moderate inverse correlation to the radial growths of other trees.

川西亚高山五种主要森林类型凋落物组成及动态

The main aim of the study was to determine changes in the species composition and structure of natural tree stands in the Białowieża Forest (BF), which occurred in the years 1975-2012, as well as to evaluate their trends, directions and rate. The study was carried out on 121 permanent research plots (50 × 50 m), which represented the most important forest phytocenoses in BF, i.e. fresh pine-whortleberry forest Vaccinio vitisidaeae- Pinetum Sokoł. 1980, fresh mixed spruce-reed grass forest Calamagrostio-Piceetum Sokoł. 1968, oligotrophic form of hornbeam - bastard balm forest Melitti-Carpinetum Sokoł. 1976, different forms of lindenhornbeam forest: Tilio-Carpinetum Tracz. 1962, alder-ash forest Fraxino-Alnetum W. Mat. 1952 and sub-boreal spruce forest on bog moss Sphagno girgenshonii-Piceetum Polak. 1962. On the plots selected, there was measured the diameter at breast height (DBH) of all trees, as well as every tree and shrub up to 1.3 m high was counted and described with reference to species. The measurements and observations were regularly repeated every 10-15 years. The results showed that over the last period of nearly 40 years, there has increased a share of common hornbeam Carpinus betulus L. in the structure of forest stands in numerous BF associations. This tree species has expanded into different forest habitats including poor, medium fertile and wetland sites. The results obtained indicate a trend towards formation of linden-hornbeam forests in BF phytocenoses. The most evident changes were recorded in hornbeam - bastard balm forest. In natural conditions of the majority of forest associations analysed, there prevailed hornbeam trees in forest regeneration, except for the stands in fresh mixed pine forest and spruce forest on bog moss. In the latter two cases, hornbeam showed signs of its presence in the last observation period. Norway spruce (Picea abies L.) retreated into oligotrophic forest associations. In the recent decades, spruce populations have been dramatically reduced in the stands in mixed coniferous and different kinds of broadleaved forests. There have also decreased a share of light-demanding tree species, such as Scots pine (Pinus silvestris L.), pedunculate oak (Quercus robur L.) and silver birch (Betula pendula L.) in BF tree stands, including their regeneration-layer. Especially, Scots pine regeneration has not been successful. In the short period of time (about 15 years) there has been observed rapid and outsized reduction of ash Fraxinus excelsior L. populations in natural conditions of alder-ash forests. All through the last 10-15 years, there has been also observed increased rate of change in stand species composition. The trend and rate of change in stand species composition point out to a possibility of human intervention towards stimulation of natural regeneration so as to preserve valuable populations of threatened tree species in the Białowieża Forest.

Trees growing in urban areas face increasing stress from atmospheric pollutants, with limited attention given to the early responses of young seedlings. This study aimed to address the knowledge gap regarding the effects of simulated pollutant exposure, specifically particulate matter (PM), elevated ozone (O3), and carbon dioxide (CO2) concentrations, on young seedlings of five tree species: Scots pine (Pinus sylvestris L.); Norway spruce (Picea abies (L.) H.Karst.); silver birch (Betula pendula Roth); small-leaved lime (Tilia cordata Mill.); and Norway maple (Acer platanoides L.). The main objectives of this paper were to evaluate the seedling stem growth response and the biochemical response of seedling foliage to pollutant exposure. Four treatments were performed on two- to three-year-old seedlings of the selected tree species: with PM (0.4 g per seedling) under combined O3 = 180 ppb + CO2 = 650 ppm; without PM under combined O3 = 180 ppb + CO2 = 650 ppm; with PM (0.4 g per seedling) under combined O3 < 40-45 ppb + CO2 < 400 ppm; and without PM under combined O3 < 40-45 ppb + CO2 < 400 ppm. Scots pine and Norway maple showed no changes in growth (stem height and diameter) and biochemical parameters (photosynthetic pigments, total polyphenol content (TPC), total flavonoids content (TFC), and total soluble sugars (TSS)), indicating a neutral response to the combined PM, O3, and CO2 treatment. The chlorophyll response to PM alone and in combination with elevated O3 and CO2 exposure varied, with silver birch increasing, Norway maple-neutral to increasing, Scots pine-neutral to decreasing, and Norway spruce and small-leaved lime-decreasing. The TPC indicated stress responses in Scots pine, small-leaved lime, and Norway maple under increased combined O3 and CO2 and in Norway spruce under single PM treatment. Hence, Scots pine and Norway maple seedlings showed greater resistance to increased PM under combined O3 and CO2 with minimal change in growth, while silver birch seedlings showed adaptation potential with increasing chlorophyll under simulated pollutant stress.

Aboveground dead wood has a range of important ecological functions, including carbon (C) storage. According to the Intergovernmental Panel on Climate Change guidelines for National Greenhouse Gas Inventories established on the basis of the United Nations Framework Convention on Climate Change and the Kyoto Protocol, Lithuania is encouraged to quantify C pools in forests, including C in living biomass, soil and dead wood. The aim of this study was to assess species-specific dead wood density (DWD) and carbon content (CC) per decay class for Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), silver birch or downy birch (Betula pendula Roth or Betula pubescens Ehrh.), European aspen (Populus tremula L.), grey alder (Alnus incana (L.) Moench), black alder (Alnus glutinosa (L.) Gaertn.), common oak (Quercus robur L.) and European ash (Fraxinus excelsior L.), as the main representative hemiboreal forest tree species. The study findings revealed that mean DWD significantly decreased, while mean CC slightly increased during the wood decomposition process, which led to carbon density (CD) reduction over five decay classes. The mean CC showed little variation among the eight tree species and ranged between 47 and 54%. The lower CDs in the dead wood of decay classes 1 and 2 were more associated with coniferous than deciduous species. The estimated CD significantly decreased in all species with increasing decay class. Dead wood at decay class 5 of Scots pine, silver or downy birch, European ash and common oak had the highest CD, followed by Norway spruce and grey alder, and the lowest CDs were obtained for European aspen and black alder.