Srovnání porostotvorné schopnosti borovice rumelské se smrkem ztepilým

Objective – to reveal wood plants of order Pinophyta which reached an age of 100 and more years, to determine their quantity, maximal age, morphometric indicators and current decorative state. Material and methods. Century trees of such species are revealed: Abies alba Mill., A. concolor Lindl. et Gord., Larix decidua Mill., Picea abies (L.) Karst., P. jesoensis (Ziebold & Zucc.) Fish. ex Carr., Pinus nigra Arn., P. peuce Griseb., P. sylvestris L., P. strobus L., Pseudotsuga mensiesii (Mirb.) Franko, Thuja occidentalis L., T. plicata D. Don and Tsuga canadensis Carr. The age of separate trees and their morphometric indexes are recorded in materials of botanical inventories of park plantings (1948–2017), in card files of park dendroflora and in park guides. Nevertheless in the modern plantings there are a lot of aged trees which age is authentically not established. Their approximate age determined by comparison of size of their diameters with average sizes of diameters of trunks of trees which age was recorded in materials of botanical inventories earlier. The common decorative effect century trees was determined by O.A. Kalinichenko’s technique [7]. Results. A portion of coniferous trees 100 years and older is 15 % (1877 specimens) of the total number of trees (11,912) of the species examined. In order of decreasing number of ancient trees, the species studied are the following: Pinus sylvestris (1035), Larix decidua (385), Picea abies (209), Thuja occidentalis (119), Pinus strobus (42), Thuja plicata (39), Pinus nigra (24), Abies alba (7), Tsuga canadensis (4), Picea jesoensis (2), Abies concolor (1), Pinus peuce (1), Pseudotsuga mensiesii (1). A comparatively small percentage of the ancient trees Picea abies (5.6 %), Thuja occidentalis (6.5 %) and Thuja plicata (4.4 %) of the total number of plantations is due to significant decrease in old trees during the abnormally high air temperature in the period 2010–2012. Conclusions. On the basis of the studies, the following maximum age of coniferous trees has been revealed: for Pinus sylvestris, P. strobus, Picea abies and Larix decidua – 155 years, for Thuja occidentalis, Pinus nigra, Abies alba, Tsuga canadensi and Picea jesoensis – 145, for Thuja plicata, Abies concolor, Pinus peuce and Pseudotsuga mensiesii – 135. This gives ground to assert that the life span of plants of these species under the conditions of Dendropark Trostjanets can exceed the maximum specified. Identified centuryold trees have different levels of general decorativeness – from 2 to 5 points scale of Kalinichenko.

Holocene palaeovegetation of the Northwestern Pirin Mountains (Bulgaria) as reconstructed from pollen analysis

Pollen analysis, plant macrofossil determination and radiocarbon dating were performed on profiles of Holocene age obtained from two subalpine lakes (2320-2340 m a.s.l.) in the Central Rila Mountains, Bulgaria. The palaeovegetational reconstruction dates back to the mid-Atlantic (6500-6700 cal. BP). The plant macrofossil record revealed that groups of Pinus mugo and Juniperus sibirica were distributed in the subalpine zone. The treeline was shaped by Pinus sylvestris and Pinus peuce and was higher (up to 2200-2300 m a.s.l.) compared with the present-day. A change to cooler summers and warmer winters after 6700 cal. BP, characterized by a rise in humidity and precipitation, stimulated the formation of a coniferous vegetation belt dominated by Pinus sylvestris, Pinus peuce and Abies alba. The pollen assemblages also indicated a dominance of deciduous trees (Quercetum mixtum-Corylus phase) at low altitudes until c. 6000 cal. BP. The sub-Boreal was characterized by a wider distribution of Abies alba in the lower part of the coniferous belt and a gradual enlargement of the areas occupied by Fagus sylvatica and Picea abies after 3800-3500 cal. BP. The macrofossil finds of Picea abies testify to its expansion after 2800 cal. BP when average temperatures dropped and precipitation increased. Traces of human disturbance in the subalpine area are continuously registered in the pollen and plant macrofossil records since 3770 cal. BP, indicating livestock-grazing, burning of dwarf-pine (Pinus mugo) for new pasture land and lowering of the treeline.

Abstract: Norway spruce is often considered to have a negative impact on a site, yet it is native to many mountain regions of Europe. The relative influence of Norway spruce on site properties has frequently been compared with that of both broadleaved and other coniferous tree species. In our study, growth, as well as needle, forest floor, and topsoil chemistry were compared between Norway spruce and introduced spruce species (white, black, red, Serbian, Sitka, and blue spruce), all growing on the same, formerly polluted mountain site. There were few differences in needle nutrient status between the introduced spruce species and native Norway spruce. The chemistry of forest floor horizons beneath some of the non-native species showed less acidity and better conditions of the soil sorption complex. There were no significant differences in the nutrient pools, indicating that the influence of the various spruce species on the site was comparable. Given the small differences observed in the various nutritional characteristics, it appears that, under the conditions of the study site, the alternative spruces had substituted for the role of Norway spruce before its recovery in the 2000s. The six spruces grew quite consistently during 2001-2012, while the mean height of Norway spruce shifted from the lowest 176 cm (2001) to one of the tallest. At 710 cm (2012), its height had become comparable with that of Sitka. The poorest performing were black spruce (due to bark beetle attack) and blue spruce (due to bud blight infestation and decline).

European High Mountain (Alpine) Vegetation and its Suitability for Indicating Climate Change Impacts

Although air pollution at the Central European “Black Triangle” sites has decreased since the 1990s, its legacy has persisted. Unlike the dominating Norway spruce that was planted again in order to restore forest cover, deciduous broadleaves were expected to improve soil. The objective of the study was to compare effect of N-fixing green alder on forest floor and soil properties compared to Norway spruce of comparable age. Forest floor layers [diagnostic horizons: litter (OL), fermentation (OF) and humified (OH)] and topsoil (A) were sampled in three replicates where green alder (GA), Norway spruce (NS), and mixture (GA + NS) were growing. Upper (OL, OF) horizons were affected positively where green alders were present and effect on OH and A horizons was weaker. Properties of GA + NS were in general intermediate to GA and NS. The improvement in soil was manifested by higher nutrient pools of N, P, K, Ca, and Mg in both OL and OF; more dry matter, organic carbon and higher cation exchange capacity were shown in OF and lower acidity in all analyzed horizons. Lower P concentrations were found in GA, nevertheless with no effect on P-pools. Forest floor and topsoil conditions confirmed green alder’s capability for improving chemistry of the formerly polluted mountain soil.

AimsThe forest floor is a significant contributor to the stand-scale fluxes of biogenic volatile organic compounds. In this study, the effect of tree species (Scots pine vs. Norway spruce) on forest floor fluxes of volatile organic compounds (VOC) was compared in boreal and hemiboreal climates.MethodsMonoterpenoid and sesquiterpene flux rates were determined during 2017–2018 using dynamic (steady-state flow-through) chambers placed on permanent soil collars on boreal and hemiboreal forest floors, where the canopy was formed by Scots pine (Pinus sylvestris), Norway spruce (Picea abies) or dominated by Scots pine with small coverage of Norway spruce and birches (Betula pendula and Betula pubescens).ResultsThe total monoterpenoid fluxes were higher from the Scots pine forest floor (boreal 23 μg m−2 h−1) and from the mixed forest floor (hemiboreal 32 μg m−2 h−1) compared to the Norway spruce forest floor in both boreal (12 μg m−2 h−1) and hemiboreal (9 μg m−2 h−1) climates. Due to higher litterfall production, the forest floor seems to be a greater source of monoterpenoids and sesquiterpenes in the hemiboreal mixed stand dominated by Scots pine compared to the boreal Scots pine stand, although the difference was not statistically significant. Forest floor VOC fluxes followed a similar seasonal dynamic in different forest stands, with the highest flux rates in spring and summer. Significant VOC sources in the boreal forest floor were synthesis and release from vegetation and living roots together with litter decomposition of fungi and other microbes, where VOCs are released from needle storage pools. Ground vegetation in the hemiboreal forest is scanty under the dense tree canopy, meaning soil processes, such as litter decomposition, microbial metabolism and root release, were likely the dominating VOC sources. VOC fluxes from the hemiboreal forest floor were reduced by increases in soil moisture.ConclusionsThis study indicates that if the warming climate changes tree species’ abundance and stand biomass, by increasing tree growth and coverage of broadleaf species, it may affect VOC fluxes from the forest floor and impact the total VOC emissions from northern soils.

Soil organic carbon and nitrogen stocks under pure and mixed stands of European beech, Douglas fir and Norway spruce

Pinus peuce is a five-needle pine native to high-elevation montane habitats of the Balkans. This study aimed to assess the diversity and composition of fungal communities associated with soil, rootlets and living needles of P. peuce at three high-altitude forest sites with different edaphic conditions and stand characteristics in south-eastern Montenegro. In total, 90 samples of each substrate (needles, rootlets and soil) were sampled. DNA amplification using ITS2 rDNA as a marker and high-throughput sequencing resulted in 23,394 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 soil and 113 in the needles, and only 8 taxa were shared. The most common fungi in rootlets were Rhizopogon mohelensis (11.0%), Suillus americanus (8.4%), and R. fallax (6.9%), in soil – Phlebiopsis gigantea (5.1%), Tylospora asterophora (2.9%), and Sollicocossima terricola (2.7%), and in the needles – Dothideomycetes sp. (17.6%), Dothideomycetes sp. (10.7%), and Leotiomycetes sp. (6.5%). The results showed that functional tissues and the rhizosphere soil of P. peuce were inhabited by a high diversity of fungi. Fungal communities in the rootlets and soil were largely determined by the site conditions such as soil properties and forest stand composition. Keywords: Pinus peuce, five needle pine, high-altitude forests, ectomycorrhiza, pathogens, saprotrophs, Montenegro

Bryophytes and lichens are two main components of the forest floor vegetation. They provide essential ecosystem services, including nutrient recycling and water regulation. Here, we contrast the species richness, cover and community composition of forest floor bryophytes and lichens in Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) dominated production forests. The study sites were located in the hemiboreal zone of southern Sweden, and represented early-, mid- and late rotation stands. Our aim was to examine the potential consequences for forest floor biodiversity from the decreasing use of Scots pine production forests in this region.Whereas Scots pine and Norway spruce stands did not differ in bryophyte cover, we found a higher cover of lichens in Scots pine stands, and highest in the intermediate aged stands. Also the species richness of lichens was higher in the Scots pine stands, while bryophyte species richness was higher in the Norway spruce stands. Differences in canopy cover and associated light transmittance to the forest floor appears to be important drivers for distinctive different forest floor communities in the Scots pine and Norway spruce stands, as revealed by Non-Metric Multidimensional Scaling (NMDS). Mean Ellenberg indicator values for bryophytes and lichens showed that species associated with Scots pine stands were characterized by their tolerance of brighter conditions, higher insolation, and better adaptation to a continental climate. Norway spruce stands instead had a comparably larger proportion of species tolerating lower light, but also indicators of higher available nutrient levels, humidity, and pH. The outcome of the Ellenberg indicator species analysis, as well as the larger cover of lichens,and adaptations to drought found among some mosses, revealed that forest floor communities are shaped by different environmental factors in Scots pine and Norway spruce production stands. These environmental differences, and the quantified shifts in forest floor communities identified in this study, indicate the large shifts in understory bryophyte and lichen species composition and abundance that is likely to occur if Scots pine stands are converted to Norway spruce.

On the Holocene vegetation history of the Central Rila Mountains, Bulgaria: The palaeoecological record of peat bog Vodniza (2113 m)

Disturbances by fire are among the most important processes that shape forest dynamics and diversity. However, the long-term variability of fire disturbance regimes in many European forests and specifically in the mountains of the Balkan Peninsula is not well understood. Here, we present the first Holocene record of fire regimes based on macrocharcoal morphologies in combination with pollen-based reconstruction of forest dynamics and fire-related strategies of prevailing mountain forests in the Rila Mountains, Bulgaria. While biomass burning followed the main trends in climate, the frequency and intensity of fire were strongly linked to fire-related coping strategies of dominant tree taxa (resisters, avoiders or invaders). Frequent fires of low intensity between 12,000 and 9000 cal year BP were concurrent with the dominance of invaders (Betula, herbs, ferns). Intermittent occurrence of low- and high-intensity surface and crown fires with longer return intervals between 9000 and 4000 cal year BP was associated with codominance of resister (Pinus sylvestris, Pinus peuce, Pinus mugo) and avoider (Abies alba and Picea abies) forest types, whereas a lengthening of the fire return interval over the past 4000 years was linked to increased abundance of P. abies. As a rising number of fire episodes may drive land cover towards more fire-adapted plant communities and towards less intense fire events, we expect increased dominance of invaders (resprouters that rapidly reach maturity stage) as well as resisters (properties protecting from fire damage) under future warmer and drier climate. This study also shows the potential of combining charcoal morphologies with pollen records to track variability in fire intensity and plant functional attributes over long timescales that are also relevant to forest management stakeholders.

Palaeoenvironmental significance of plant macrofossils from the Piànico Formation, Middle Pleistocene of Lombardy, North Italy

This research relates to occurrence of some morphological and ecological features of native woody plants in Mavrovo National Park situated in north-western Republic of North Macedonia on an area of about 73,000 ha. The Park represents more than 45% of the dendroflora and nearly 19% of the forest communities in the country. The observations were done during the past fifteen years covering different aspects of both individual and social life of the dendroflora, and various ecological conditions. In this context, dozen dendrological phenomena were found to be important to note. Namely, very old individual trees of the Balkan endemic species and Arcto-Tertiary relic of horse chestnut (Aesculus hippocastanum) thriving as riparian population were found; old European hop-hornbeam (Ostrya carpinifolia) individuals on remote sites; old Austrian pine (Pinus nigra), and sycamore (Acer pseudoplatanus) trees; old groves of common ash (Fraxinus excelsior), and of Austrian pine; firs (Abies borisii-regis and A. alba) with form of smooth or rough bark and aggressive territorial expansion on thermo-mesophilic sites. European beech (Fagus sylvatica) with oak-bark form (‘quercoides’) also was found. Furthermore, the occurrence of the hemiparasite juniper dwarf mistletoe (Arceuthobium oxycedri) on savin juniper (Juniperus sabina) was identified. In addition, finding site of Cotoneaster parnassicus was found. A few phenomena were observed concerning the spruce-fir forest community (ass. Abieti-Piceetum scardicum): dieback of Norway spruce individuals (Picea abies), emergence of Balkan pine (Pinus peuce) initial population in the vicinity and presence of barberry (Berberis vulgaris) as steppe floral element together with expressed mesophilic species.

Air Pollution Status of the Bulgarian Govedartsi Ecosystem