Growth and Productivity of Non-Indigenous Woody Species in the Middle Urals

Climate warming has been recorded over the last decades. The air temperature in Yekaterinburg has been rising since the 1930s. Temperatures dropped sharply in 1940–1949, then rose sharply and fell again, especially in 1967–1968, when many large introduced species considered to be adapted died: Phellodendron amurense Rupr. and Pseudotsuga taxifolia (Lindl.) Britt. Due to the cyclical nature of weather conditions, it was necessary to assess the features of adaptation and state of the introduced plants in recent years. Snowless autumn and winter, temperatures above zero in early spring are unfavourable for many species, especially or conifers. Thus, in 2014 much snow fell on October 16 and melted in 2 weeks, temperatures below zero did not afford plants to prepare for the winter; in March 2015 the temperature rose up to +10 °C while the ground temperature was below zero for a long time. As a result of physiological dryness 100 % of specimens of variegated forms of northern white cedar Thuja occidentalis L. `Ellwangeriana Aurea`, `Ericoides` died. In other forms the leafage died to the snow cover level and recovered after abundant rains: `Aurea spicata`, `Gold Pearl`, `Golden Globe`, `Lutescens`, `Semperaurea` and `Wareana Lutescens`. Due to a steady increase in the sum of positive temperatures and reaching a certain age, many conifer species entered the fruiting stage and gave self-seeding: Pinus peuce Grieseb, Pinus strobus L., Picea canadensis (Mill.) Britt. et al., Picea pungens Engelm., Pseudotsuga taxifolia (Lindl.) Britt., and Abies sachalinensis (F. Schmidt) Mast. In the warmest year of 2016, the latter gave an abundant yield – red-brown cones with protruding seed scales; a strong wind dropped them all. They remained under the snow for the winter and did not crumble (probably, the fruits were unripe), so Abies sachalinensis was mistaken for Keteleeria fortunei (A. Murray bis) Carrière), which has cones that do not crumble. Unusual flowering was observed in Crataegus oxyacantha L. `Rosea Plena`, Mespilus germanica L., Syringa reflexa C.K.Schneid, Hamamelis virginiana L. With the rise in average annual temperatures, the number of years with abnormal weather conditions increased and the condition of some plants deteriorated. For citation: Semkina L.A., Tishkina E.A. Growth and Productivity of Non-Indigenous Woody Species in the Middle Urals. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 100–109. DOI: 10.37482/0536-1036-2021-6-100-109

Three species of bark beetles (Coleoptera: Curculionidae, Scolytinae) on Pinus peuce in Pirin Mountains in Bulgaria

In 2020 and 2021, three species of bark beetles (Coleoptera: Curculionidae, Scolytinae) were established on Macedonian pine (Pinus peuce) in the region of Vihren hut in Pirin Mts. Branches, damaged by snow were collected and studied in laboratory conditions. As a result, 24 specimens of Ips amitinus were reared in 2020 and 81 specimens of I. amitinus, Crypturgus pusillus and Pityogenes chalcographus in 2021. The most abundant species was I. amitinus with 75.2%, followed by P. chalcographus (21.9%) and C. pusillus (2.9%).

Impact of Mixing on the Structural Diversity of Serbian Spruce and Macedonian Pine Endemic to Relict Forest Communities in the Balkan Peninsula

The aim of this paper is to analyze the effect of different degrees of mixing on the diversity structure in stands left to spontaneous development. The research included two communities of species endemic to the Balkan Peninsula—the Serbian spruce (Picea omorika Pančić Purk.) and the Macedonian pine (Pinus peuce Griseb). Data from eight sample plots were used in the research. The changes in diameter and height structure, spatial arrangement of trees, and diameter differentiation were analyzed. The analyzed parameters of structural diversity show relatively low to moderate values. Results showed an increase in mixing was reflected in the width and shape of distributions. A spatial analysis of stands with a higher degree of mixing showed a tendency towards a random to regular distribution of individuals, in contrast to stands with a lower degree of mixing which showed a tendency towards a clump distribution. The pronounced species’ dimensional and spatial diversity confirms their importance to the condition of modern forest management. Significant differences in the change of structure are shown by stands with a share of admixed species of above 20% by volume. The obtained results refer to stands left to spontaneous development, suggesting than an active research and management approach must be assumed to realize the goal of protecting rare forest ecosystems.

Patterns of Fungal Diversity in Needles, Rootlets and Soil of Endemic Pinus Peuce

Pinus peuce Griseb is five-needle pine native in high-altitude montane habitats of the Balkans. The aim was to assess the diversity and composition of fungal communities associated with the soil, rootlets and living needles of P. peuce at three high-altitude forest sites with different edaphic conditions and stand characteristics in southeastern Montenegro. In total, 90 needle, 90 rootlet and 90 soil samples were sampled. DNA amplification using ITS2 rDNA as a marker and high-throughput sequencing resulted in 17,620 high-quality reads, representing 825 fungal taxa. There were 52.5% Basidiomycota, 43.9% Ascomycota and 3.6% Mucoromycotina. There were 118 unique fungal taxa in the rootlets, 230 in the soil and 113 in the needles, with 8 taxa were shared. The most common fungi in rootlets were Rhizopogon mohelensis (11.0%), Suillus sibiricus (8.4%), R. fallax (6.9%), in the soil – Phlebiopsis gigantea (5.1%), Tylospora asterophora (2.9%), Sollicocossima terricola (2.7%), and in the needles – Dothideomycetes sp. 3360_7 (17.6%), Dothideomycetes sp. 3360_10 (10.7%), Leotiomycetes sp. 3360_16 (6.5%). The results showed that the functional tissues and the rhizosphere soil of P. peuce were inhabited by a high diversity of fungi, which were largely specific to each particular substrate, while. the site conditions had only limited effect on associated fungal communities. Associated fungal communities were largely determined by the host tree species, substrate properties and functional capabilities of associated fungi.

Stable Isotopes Reveal Climate Signal Hidden in Tree Rings of Endemic Balkan Pines

Studies report the good potential of Pinus heldreichii (PIHE) and Pinus peuce (PIPE) for developing long chronologies from living trees and warn that the climate signal is weak in tree-ring widths of PIHE, and particularly PIPE. The goals of the study were to develop long chronologies, and to analyze the climate–growth relationship and potential for long climate reconstructions using tree-ring widths (TRW) and stable carbon isotopes ratios (δ13C) in tree rings at the northern edge of species distribution in the eastern part of Montenegro. The PIHE TRW chronology covers the period 1571–2013 (443 years) and the PIPE TRW chronology 1521–2013 (493 years). The temperature signal in PIHE TRW is weak and the precipitation signal is non-existent. PIPE has no climate signal in TRW. Both studied species have very similar δ13C chronologies, which allows us to merge isotope chronologies into a single composite δ13C Pinus chronology. The composite chronology has a strong signal related to average monthly temperature in June, July, and August and monthly values for cloudiness in July and August, with r > 0.6 and r < −0.6 for individual months, respectively. The climate signal was enhanced when June, July, and August values were merged into seasonal variables. The temporal stability of temperature, precipitation and cloudiness signals is consistent. The spatial extent of the δ13C chronology extends over a very large region, including all surrounding countries.

Relationships among some pines from subgenera Pinus and Strobus revealed by nuclear EST-microsatellites

Genetic relationships among 12 taxa from subgenera Pinus and Strobus were studied through fourteen microsatellite markers, previously developed for Pinus taeda. To our knowledge, this is the first comparative study of pines using nuclear EST-microsatellites (EST-SSRs). The total number of detected alleles in all investigated taxa was 72 (5.14 in average). The numbers of alleles per locus and PIC values for estimated markers ranged from 3 to 7, and from 0.43 to 0.81, respectively. Presented results are in accordance with majority of previous genetic investigations and infrageneric classification of genus Pinus up to the sectional level, while subsectional position of some species has still not dismissed, especially regarding relict ones. According to nuclear EST-SSRs, Pinus heldreichii is in early-diverging position within subsection Pinaster and shows the greatest closeness with P. halepensis, while Pinus peuce doesn't have basal position within subsection Strobus being more close to P. strobus than to P. wallichiana. Furthermore, the closest connections in subsection Pinus were found between two Pinus nigra subspecies (dalmatica and nigra) as well as between P. sylvestris and P. mugo.

Density of red squirrels and their use of non-native tree species in the Rogów Arboretum

The aim of the study was to compare the densities of red squirrel (Sciurus vulgaris) in the arboretum and a neighbouring forest and to investigate which tree species the squirrels used. The study was conducted in the area of the Rogów Arboretum (53.76 ha) and the so-called Zimna Woda and Wilczy Dół forest complexes (altogether 536 ha), all being part of an Experimental Forest Station in Rogów. The density of squirrels in the arboretum and the neighbouring forest was estimated and compared by means of snow tracks on transect routes. Changes in the abundance of squirrels throughout one year as well as their behaviour were determined on the basis of direct observations along transects running through the arboretum. More than half of the area of the arboretum was searched in order to record feeding signs of squirrels. Additionally, trees with bark stripping were recorded. The density of snow tracks was higher in the arboretum (0.19 tracks/100 m/24 h) than in the neighbouring forest (0.09 tracks/100 m/24 h). The largest number of observations of red squirrels along transects was made between February and April, in July and August and in October and November. In about half of the cases, squirrels were feeding on one of six non-native tree species (most often on cones of Macedonian pine, Pinus peuce). Feeding signs were found on 39 plots (17%) and 16 different tree species. The most numerous feeding signs were found on plots with Douglas fir (Pseudotsuga menziesii) and also on plots with the western hemlock (Tsuga heterophylla), Swiss pine (Pinus cembra), mountain silverbell (Halesia monticola) as well as shagbark (Carya ovata) and shellbark hickories (C. laciniosa). On eight plots, trees with signs of bark stripping were found, most commonly on Sawara cypress (Chamaecyparis pisifera). Its soft bark was probably used to build dreys. In the area of the arboretum, the natural food sources (seeds of native trees) are supplemented with numerous non-native tree species, which seeds are also consumed by squirrels. The highly abundant and diverse food sources promote a higher density of the red squirrel in the area of the arboretum. Additionally, when tree seeds are scarce in the neighbouring forest, squirrels migrate into the arboretum.