Norway maple (Acer platanoides) and pedunculate oak (Quercus robur) demonstrate different patterns of genetic variation within and among populations on the eastern border of distribution ranges

Norway maple (Acer platanoides L.) is a key species of broadleaved forests whose population genetics is poorly studied using modern genetic tools. We used ISSR analysis to explore genetic diversity and differentiation among 10 Russian populations on the eastern margin of the species range of distribution, and to compare the revealed patterns with the results of our population genetic studies of pedunculate oak (Quercus robur L.). In the first set comparatively high heterozygosity and allelic diversity were found (expected heterozygosity H_E = 0.160 ± 0.033, number of alleles n_a = 1.440 ± 0.080, effective number of alleles n_e = 1.271 ± 0.062) in comparison with strongly fragmented and geographically isolated small maple stands of the second set (H_E = 0.083 ± 0.011, n_a = 1.281 ± 0.031, n_e = 1.136 ± 0.019). A relatively high genetic differentiation among populations was detected (the proportion of the inter-population component of total genetic variation, G_ST = 0.558 ± 0.038). In the Cis-Urals, local groups of populations that are confined to the northern, middle and southern parts of the Urals were identified. On the contrary, the current significant fragmentation of the pedunculate oak distribution area in the same study area did not lead to any noticeable genetic differentiation among the majority of populations, the values of the population genetic diversity were very similar in different parts of the Southern Urals.

FORMATION OF ARTIFICIAL PROTECTIVE LINEAR PLANTS IN THE CONDITIONS OF THE EXPERIMENTAL FARM OF FSBEI HE "VSAU"

Artificial protective linear plantings in the experimental farm of the Federal State Budgetary Educational Institution of Higher Education "VGAU" were created more than 60 years ago. English oak was used as the main species for cultivation in cultures. The plantings are presented with a width of 18.0 m to 35.0 m with the placement of rocks 1.5 - 5.0 x 0.7 - 3.0 m. Due to the abundance of self-seeding, a dense structure of the lower profile has formed. To study the characteristics of the growth and condition of rocks, test plots were laid in the ZFN according to generally accepted methods in forest inventory and protective afforestation. English oak has a preservation of 50.1-60.1% and, at the same time, its average diameter is from 23.8-25.3 cm, the average height is 20.8-24.0 m. The best results were noted in plantations where the English oak grown with Norway maple and yellow acacia when placed 5.0 x 3.0 m. Silvicultural and reclamation assessment of plantings 4a. When creating protective plantations with the participation of fast-growing species with a placement of 1.5 x 0.7 m, 2.5 x 0.7 m English oak. enter when separating it in rows from fast-growing rocks. In cultures at the age of 62 years with a predominance of pedunculate oak, a convex transverse profile of the plantation is formed and, at the same time, the height of the middle rows is 10.1% higher than the edging rows, the average diameter of the middle rows is less than the extreme ones by 7.5%. Protective plantations transform agricultural landscapes, change the ecology of the territory, serve as boundaries and boundaries of vegetation in inter-strip fields.

Protective afforestation in agroforestry landscapes of the Middle Don basin

The use of forest reclamation facilities to transform the landscapes of the Middle Don basin of the European part of Russia is an important aspect in improving the natural conditions of agricultural territories. In the Central Black Earth Region, they occupy an area of 600000 hectares and form the ecological framework of forest agrarian landscapes. The purpose of our research is to establish the optimal conditions for the growth and reforestation efficiency of protective plantations in different conditions. Modern methods and approaches were used for forestry and land reclamation assessment of forest belts. In artificial linear plantings, the biometric indicators of growth and safety in fast-growing species are most pronounced at the initial density of creation and 3334 pcs/ha. The best companions for joint cultivation of English oak are Norway maple and yellow acacia. In the conditions of typical chernozem, the highest values for the growth of rocks are noted. In winter, protective plantations accumulate snow water reserves of 435-430 m3/ha, which makes it possible to form an additional yield of grain crops by 320-430 kg/ha in the strip zones.

The Use of an Unmanned Aerial Vehicle for Tree Phenotyping Studies

A strip of 20th-century landscape woodland planted alongside a 17th to mid-18th century ancient and semi-natural woodland (ASNW) was investigated by applied aerial spectroscopy using an unmanned aerial vehicle (UAV) with a multispectral image camera (MSI). A simple classification approach of normalized difference spectral index (NDSI), derived using principal component analysis (PCA), enabled the identification of the non-native trees within the 20th-century boundary. The tree species within this boundary, classified by NDSI, were further segmented by the machine learning segmentation method of k-means clustering. This combined innovative approach has enabled the identification of multiple tree species in the 20th-century boundary. Phenotyping of trees at canopy level using the UAV with MSI, across 8052 m2, identified black pine (23%), Norway maple (19%), Scots pine (12%), and sycamore (19%) as well as native trees (oak and silver birch, 27%). This derived data was corroborated by field identification at ground-level, over an area of 6785 m2, that confirmed the presence of black pine (26%), Norway maple (30%), Scots pine (10%), and sycamore (14%) as well as other trees (oak and silver birch, 20%). The benefits of using a UAV, with an MSI camera, for monitoring tree boundaries next to a new housing development are demonstrated.

Assessment of the Structure and Diversity of Latvian Acer platanoides Populations Using Cross-Species Nuclear Microsatellite Markers

Acer platanoides L. (Norway maple) is the most widespread native maple species in Europe, with a distribution from south and central Europe to northern Europe and Scandinavia. Acer platanoides is widespread throughout the territory of Latvia, and is mainly found in mixed broadleaf and conifer stands. The genetic diversity and differentiation of Latvian A. platanoides populations was analysed. Sampled populations were located throughout the territory of Latvia, and were selected to represent a range of ecological conditions, with differing levels of anthropogenic impact. A total of 496 individuals from 21 populations were analysed with eight microsatellite markers, which were developed from related Acer species. The obtained molecular data revealed a moderate level of polymorphism, and the analysed Latvian A. platanoides populations were moderately differentiated. This study provides an initial assessment of the genetic diversity and differentiation of Latvian A. platanoides populations, and is also one of the first reports of the analysis of A. platanoides populations using microsatellite markers. The results can be utilised to define A. platanoides genetic resource stands to ensure conservation of a wide range of germplasm.

Features of coarse woody debris volume formation in fresh sudibrova conditions in Zmiini islands tract of Kaniv Nature Reserve

Dead wood (woody debris) is an important component of forest ecosystems. It performs a number of ecological and environmental functions. The article studies the peculiarities of the formation of coarse wood detritus volume and its qualitative structure in forests in the conditions of fresh sudibrova of the Zmiiini Islands tract of Kaniv Nature Reserve. The study of dead wood was carried out in 140-year-old pine-oak forests of natural origin on a permanent sample plot (0.24 ha) by identifying and measuring of standing and lying deadwood components. It was found that dead wood in the forest ecosystem was formed due to the dying of trees of five species: common oak (Quercus robur L.), Scots pine (Pinus sylvestris L.), Norway maple (Acer platanoides L.), small-leaved lime (Tilia cordata Mill.) and common hornbeam (Carpinus betulus L.), and has a volume 56.3 m3·ha–1. Dead wood volume is dominated by standing dead trees — 82.1%, and the share of lying dead wood, respectively, is 17.9%. The main part of dead wood volume is formed by two tree species — common oak and Scots pine, the share of which together is 94.3%. Common oak and Scots pine is characterized by a predominance of standing dead wood, while for other tree species — lying dead wood. In general, dead wood is formed by detritus of I–IV classes of destruction, at the same time detritus of class II decomposition has a significant advantage (70.5%), recently dead wood has a much smaller share (I class, 24.8%), and other classes of destruction have insignificant shares, which together do not exceed 5.0%. No woody detritus of the last (V) class of destruction was detected. Volume of standing dead wood is 46.2 m3·ha–1, and is formed by whole and broken dead trees. In terms of species composition, common oak has a significant advantage (74.5%), Scots pine has a much smaller share (25.1%), and the share of Norway maple is insignificant (0.4%). The total standing dead wood volume is dominated by wood of class II destruction (33.0 m3·ha–1, 71.4%) compared with class I (13.2 m3·ha–1, 28.6%). Lying dead wood is represented by four classes of destruction (I–IV), however, no woody debris was found at the late (last) stage of decomposition (class V). In terms of volume, the second class of destruction has an absolute advantage (6.7 m3·ha–1, 66.3%), much less class III detritus (2.3 m3·ha–1, 22.8%). Lying dead wood of common oak is represented by all four classes of destruction, among which III (40.5%) and I (33.3%) classes predominate. Lying dead wood of other tree species is characterized by the predominance of II or III classes of destruction. The main factors in the formation of woody detritus in the pine-oak forest in the Zmiiini Islands tract could be the impact of adverse climatic conditions (long periods without precipitation in summer), which led to the weakening of individual trees and their death, gusts of wind that broke individual tree trunks, low-intensity snow breaks, and the influence of biotic factors (insects, pathogens).

Quantitative and qualitative attributes of dead wood in dominated by Carpinus betulus L. forests in Kaniv Nature Reserve

The article presents the quantitative and qualitative attributes of dead wood in forests dominated by Carpinus betulus L. in Kaniv Nature Reserve. The study was conducted in 130–140-year natural common hornbeam forests on two permanent sample plots of 0.24 ha each by identifying and measuring all components of standing and lying (fallen) dead wood. It was found that wood detritus has an average volume of 39.8 m3/ha consists of standing dead trees (23.1%) and fallen dead wood (76.9%). The species composition is dominated by common hornbeam (96.5%), and the share of Norway maple (Acer platanoides L.) is low (3.5%). Wood of II (13.2 m3/ha, 33.1%) and III (12.2 m3/ha, 30.7%) classes of destruction predominates. Standing dead wood is formed by only one tree species — common hornbeam and has an average volume of 9.2 m3/ha. It is represented mainly by standing broken trees. The volume of standing dead wood is dominated by wood detritus of the II stage of decomposition (95.7%). Fallen dead wood is formed by two tree species — common hornbeam (95.4%) and Norway maple (4.6%), has an average volume of 30.6 m3/ha. It is represented by whole uprooted and broken fallen trees (trunks), fragments of fallen trees (trunks) and rough branches. Lying dead wood is represented by detritus of all five classes of decomposition, but wood of III (12.2 m3/ha, 39.9%) and IV (9.6 m3/ha, 31.4%) classes predominates. The volume of fallen dead wood is mainly formed by components with an average diameter of 10.1–30.0 cm (75.7%). The diversity of fractions and components, structural features, sizes and stages of decomposition of dead wood can be important in the formation of potential habitats and substrates for a number of species of living organisms.

Impacts of Wire Basket Retention and Removal on Whole Tree Stability and Long-term Growth1

When balled-and-burlapped trees are planted, a decision must be made regarding whether the wire basket, burlap, and other packing materials should be removed (completely or partially) or retained. While past research has failed to show a significant impact of either approach with regard to initial growth and establishment, many professionals still question whether a decision to leave the wire basket intact at planting will have longer-term impacts to tree health and stability. In this study, we revisit two nursery trials first initiated in 2011 and 2012 to assess the impact of burlap folding, and full wire basket removal, partial removal, or retention on tree growth and root anchorage five to six growing years after planting. We found that neither stem caliper (min P = 0.249) nor twig elongation (min P = 0.297) differed among removal treatments with the Norway maple (Acer platanoides L.) and ‘Skycole' honeylocust (Gleditsia triacanthos L. var. inermis) trees used in this study. Similarly, we were unable to detect any differences in rooting strength among the removal treatments tested (min P = 0.154). These results serve as further evidence that wire baskets are not a cause of early tree mortality or instability. Index words: Arboriculture, biomechanics, growth and longevity, nursery production, static-pull test, transplanting, transplant shock. Species used in this study: Norway maple (Acer platanoides L.); ‘Skycole' honeylocust (Gleditsia triacanthos L. var. inermis).