Planted Tree Species Research Articles

Bark-stripping of African mahogany trees (Khaya spp.) by cattle in silvopastoral systems in Brazil

African mahogany (Khaya spp.) produces high-value wood, and its cultivation is expanding in tropical regions. The silvopastoral system is an alternative method for growing timber trees, but may involve cattle stripping bark from trees, which limits its usefulness. We evaluated cattle bark-stripping rates in two African mahogany species, K. grandifoliola and K. senegalensis, in a silvopastoral system with Guinea grass, Panicum maximum, in South-eastern Brazil. Cattle had free access to plantations of both tree species for 2 weeks in May 2018 and July 2019, when trees were 5 and 6 years old, respectively. In 2018, we found bark-stripping only in K. grandifoliola, but in 2019 both species were bark-stripped. The proportion of bark-stripped trees was higher for K. grandifoliola than for K. senegalensis. Considering both years, 29/155 (18.7%) K. senegalensis trees and 106/153 (69.3%) K. grandifoliola trees had some of their bark-stripped by cattle. Bark-stripped trees had lower trunk diameter growth than unaffected trees, and their growth was affected by the degree of bark-stripping. Some trees were girdled by bark-stripping. These trees dried up, and some of them fell down 1 year after girdling. In 2019, despite the high herbage mass, levels of crude protein in the pasture were very low, which may have stimulated bark-stripping. Although we could not identify the reasons for bark-stripping, we recommend avoiding the use of silvopastoral systems with cattle and African mahogany in times of the year when pasture has a low quality.

SPECIFIC FEATURES OF FORMATION OF VINNYTSIA FOREST PARK PLANTATIONS RESISTANT TO RECREATIONAL LOADS

The research conducted was to assess the characteristics of intraspecific and interspecific interaction of the dominant tree species in the forest-park plantations of Vinnytsia green zone, as well as to determine the priority taxation indicators of formation of forest stands with high competitive ability.As a result of the research it was found that the main indicators that directly affect the competitive properties of forest elements are the sanitary condition of forest plantations; the composition of the stand and its storey structure; the undergrowth and underwood availability; biological and ecological features of individual tree species; stand completeness; age of planting; type of forest vegetation conditions; specific features of microclimate and microrelief. The analysis of the sanitary condition of the trial areas shows that the degree of competitive ability of forest plantations with a high number of dead or damaged trees is much lower than that in plantations with better sanitary conditions. The dependence of the competitive ability and the stand growth intensity on its completeness and the type of forest-park landscape was also studied. Thus, closed types of stands are characterized by a high degree of competitiveness. In semi-open types of forest-park landscapes the rate of growth intensity is the highest. The competitive ability of trees in this type of landscape is quite low. After analyzing the temperature regime of different forest parks, it was found that in hot weather the ambient temperature in the forest park is much lower than the air temperature in the open area. Thus, in hot uncomfortable weather, the optimal type of forest for recreation is a closed type of landscape of vertical closure. The air temperature here can be significantly lower (up to 15˚C) compared to the open space, what creates suitable conditions for a comfortable rest. Analysis of the humidity of forest parks showed that under the cover of forest stands humidity is higher than in the open area, thus recommendations for choosing the type of forest landscape for recreation purposes depend on the initial humidity. Key words: recreation, forest parks, intraspecific interaction, forest park landscape, winter hardiness, temperature regime, light intensity, air humidity.

A simple-to-use management approach to boost adaptive capacity of forests to global uncertainty

Given the uncertainty of global environmental changes, forest managers need reliable and science-based tools to support planning decisions. To evaluate the state of forests as well as the outcomes of new management practices aimed at fostering the adaptive capacity of forest ecosystems, methods and metrics for practitioners should be self-explanatory, based on easily-available data, and straightforward to use. Here, we present and apply the functional network approach, a trait-based approach that scales-up from species functional traits to community-level functional diversity and from stands to landscape-level functional connectivity, to guide sustainable forest management when faced with global change. In the functional network approach, (1) tree and shrub species are clustered into functional groups based on selected functional traits, (2) forest stands become the nodes of the network, and (3) functional traits can be exchanged between nodes according to species dispersal capacity via functional connectivity. We complemented the functional network approach with an assessment of stand-level vulnerability to natural disturbances. This new approach was applied to a mixed temperate forest landscape in south-eastern Canada to test four management scenarios varying in intensity (5–40% of the landscape area) and silvicultural strategy, including planting tree species from rare functional groups or harvesting tree species from predominant functional groups. Managed stands were ranked according to functional diversity and vulnerability to disturbances, and species were considered for planting based on their contribution to functional diversity and level of vulnerability. We found that a species-rich forest may be a functionally poor ecosystem so its adaptive capacity and resilience may be strongly compromised in the face of high global uncertainty. In addition, both functional diversity and connectivity increased with more intense management, and when functionally rare species were planted. By adopting the functional network approach, forest practitioners have a new simple-to-use tool to evaluate landscape-level functional diversity, vulnerability, and functional connectivity. This tool can be used to inform both plans for mitigating natural disturbances and strategies for enhancing overall ecosystem adaptive capacity to future environmental conditions and societal demands.

Growth dynamics of fast-growing tree species in mixed forestry and agroforestry plantations

In recent years, plantations of fast-growing tree species have emerged as a possible way to meet the increasing demand for biomass for renewable energy in Europe. Agroforestry plantations including fast-growing tree species could be an attractive option because they reduce land competition for biomass and food production while providing forest benefits. Today, the species interactions that determine whether a given mixture will be more productive than the corresponding monocultures are still poorly understood. Our objective was to assess the performance of fast-growing trees, i.e. poplar (Populus nigra × P. deltoides) and alder (Alnus glutinosa), in association with herbaceous species either N2-fixing species (succession alfalfa (Medicago sativa) and clover (Trifolium pratense)) or graminoids (succession of wheat (Triticum aestivum) – triticale (Triticosecale) – temporary grassland consisting of mixtures of perennial ryegrass (Lolium perenne) and fescue (Festuca ovina)), respectively, and in association together. We compared tree growth in mixed stands to growth in the respective tree monocultures. An experimental plantation composed of three blocks including the different treatments was set up in 2014 in northeastern France. In the forest mixture, poplar and alder were planted in alternating rows, and in the agroforestry plots, every second line of trees was replaced by the crops. No fertilizers (of any kind) were used during the experiments. During six growing seasons, tree growth (height and diameter at breast height) was monitored monthly in the agroforestry stands, the forest mixture stand and the two tree monocultures. By the end of 2019, poplar stem height in association with N2-fixing crops (alfalfa, then clover) was higher than in the forest mixture and the monoculture. During the warmest growing season with a marked dry period in June-July (2018), poplar height growth rate in the agroforestry treatment was between three and five times higher than for the poplars in the monoculture and the forest mixture. A facilitation process in the agroforestry plantations could explain this result due to a significant enrichment of the soil in nitrogen by the N2-fixing crops. This result only appeared several years after tree planting, and management actions were necessary in order to control the strong competition between crops and trees during the early stages. In the forest mixture, poplars associated with alders were smaller than in their monoculture, in spite of a stratification of the canopies of the two species. For alders, tree growth did not appear to be affected by either an association with graminoids or with poplar.

Soil carbon, nitrogen and phosphorus ecological stoichiometry shifts with tree species in subalpine plantations.

Understanding ecological stoichiometric characteristics of soil nutrient elements, such as carbon (C), nitrogen (N) and phosphorus (P) is crucial to guide ecological restoration of plantations in ecologically vulnerable areas, such as alpine and subalpine regions. However, there has been only a few related studies, and thus whether and how different tree species would affect soil C:N:P ecological stoichiometry remains unclear. We compared soil C:N:P ecological stoichiometry of Pinus tabulaeformis, Larix kaempferi and Cercidiphyllum japonicum to primary shrubland in a subalpine region. We observed strong tree-specific and depth-dependent effects on soil C:N:P stoichiometry in subalpine plantations. In general, the C:N, C:P and N:P of topsoil (0–10 cm) are higher than subsoil (>10 cm) layer at 0–30 cm depth profiles. The differences in C:N, N:P and C:P at the topsoil across target tree species were significantly linked to standing litter stock, tree biomass/total aboveground biomass and Margalef’s index of plant community, respectively, whereas the observed variations of C:N, N:P and C:P ratio among soil profiles are closely related to differences in soil bulk density, soil moisture, the quantity and quality of aboveground litter inputs as well as underground fine root across plantations examined. Our results highlight that soil nutrients in plantation depend on litter quantity and quality of selected tree species as well as soil physical attributes. Therefore, matching site with trees is crucial to enhance ecological functioning in degraded regions resulting from human activity.

Investigating the abundance and flight period of bark beetles (Coleoptera: Curculionidae: Scolytinae) over elevational gradients in Sitka spruce forests

Abstract A warming climate, as predicted under current climate change projections, is likely to influence the population dynamics of many forest insect species. Numerous bark beetle species in both Europe and North America have already responded to a warming climate by significantly expanding their geographical ranges. The aim of the current study was to investigate how populations of bark beetles within stands of Sitka spruce, a widely planted non‐native commercial plantation tree species in the U.K., were likely to respond to a warming climate. Experimental plots were established in stands of Sitka spruce over elevational gradients in two commercial forest plantations, and the abundance and emergence times of key bark beetle species were assessed over a 3‐year period using flight interception traps. The air temperature difference between the lowest and highest experimental plot in each forest was consistently >1°C throughout the 3‐year period. In general, the abundance of the most dominant bark beetle species (e.g. Trypodendron, Dryocoetes, Hylastes spp.) was higher, and emergence times tended to be earlier in the year at the lower elevation plots, where temperatures were higher, although not all bark beetle species responded in the same manner. The results of the study indicated that, under the projected future climate warming scenarios, monoculture Sitka spruce stands at low elevations may potentially be more vulnerable to significant outbreak events from existing or invasive bark beetle species. Hence, consideration of establishing more resilient forests of Sitka spruce by diversifying the species composition and structure of Sitka spruce stands is discussed.

On the state of the ground cover of shaded areas in urban landscaping objects

It has been established that in municipal forestry of Stavropol (streets, squares, boulevards, parks) mixed plantations of broad-leaved tree species Tilia cordata Mill., Acer pseudoplatanus L., A. platanoides L., Aesculus hippocastanum L., Fraxinus excelsior L., Quercus robur L., prevail, which increases the shading conditions for lawns arranged under their canopy. With sparse and single-row planting of trees, lawn grass is in conditions of temporary shading and does not significantly suffer (lawns of good and satisfactory quality). In places with multi-row and group placement of tree plantations, the grass of lawns is in conditions of both temporary and permanent shading and is thinned up to 40–60 %, the relative amount of sunlight (RAS) is 2.1–9.2 % (mediocre and poor lawns). In conditions of constant intensive shading with a RAS of 0.6–2.6 %, turf grasses completely fall out, a dead cover forms, which reduces the quality of greening. Usually sparse grass are sown with fast-growing turf grasses annually. The issue of turfing of the shaded areas of parks with local forest grasses Brachypodium sylvaticum (Huds.) P. Beauv., Dactylis polygama Horvat., Festuca gigantea (L.) Vill., Poa nemoralis L. (RAS 2.1–5.8 %) and sedge Carex divulsa Stokes, (RAS 1.0–4.2 %) and the conservation of forest herbaceous cenoses is discussed. In shady parks, the use of ground cover introduced species Vinca minor L., Hedera helix L, and the herbaceous perennial Helleborus caucasicus A. Braun (RAS 1.2–7.4 %) is promising.

Assessments of growth performance, crown structure, stem form and wood property of introduced poplar clones: Results from a long-term field experiment at a lowland site

Climate change brings about more frequent short-term waterlogging leading to unfavorable conditions for tree growth. Poplar is a preferred tree species for fast-growing plantations. Although limited short-term comparative studies exist with poplars that examine clonal variation in growth and physiological responses to waterlogging, a comprehensive assessment on growth performance, crown structure and wood property of poplar clones is lacking from a long-term study. This study compares the clonal variations in survival rate, growth, crown structure, stem form and wood property of poplar clones to better match the genotype with specific site. In line with the result of the preliminary evaluation, 17 poplar clones were harvested to further investigate crown structure, stem form and wood property after 24 growing seasons. A significant difference in tree growth was observed among the clones, ranging from 1.08 to 2.64 m3 for tree volume, whereas male clones generally had a better growth performance than the female. Hierarchical cluster analysis indicated the 17 poplar clones can be classified into three distinct groups in term of mean values of branching angle, branch numbers and branch base diameter. There existed visible differences in breast-height form factor and height-diameter ratio among the poplar clones, and four distinct groups can be divided based on Euclidean distance of stem form indexes. Significant clonal variations in wood basic density (WD) and microfibril angle (MFA) were observed among the sampled clones, and the mean clonal WD and MFA at breast height ranged from 0.325 to 0.390 g/cm3 and 11.8 to 16.7° respectively. Based on the TOPSIS method, a comprehensive assessment of adaptability and prioritization of the 17 clones was made from tree volume growth, stem form, branching traits and wood density, and some superior poplar clones were recommended for future applications in the similar lowland sites.

The suitability of forest tree species for enrichment planting at PT Semitau Region, West Kalimantan

Forest tree enrichment can improve biodiversity and ecosystem functions. Tree enrichment planting in the riverside rehabilitation area of palm oil plantation needs to be monitored to prevent the risk of erosion and sedimentation. However, regular monitoring of enrichment planting is not yet optimally carried out including the benefits and identified suitable species through field observations. This study was aimed to determine the three most suitable tree species to be recommended for enrichment planting in the riverside rehabilitation areas at PT Semitau Region oil palm plantation. Samples were determined through a combination of linear systematic sampling methods. The measured variables included the survival percentage, health, diameter, height, light intensity, and soil analysis. The results showed that the three species had the best adaptability, namely kawi (Shorea balangeran), pulai (Alstonia spp.), and ubah (Syzygium darifolium) with 21%, 15%, and 10% dominance frequency, respectively. Total dominance frequency of 45 % for all three species are expected to be useful information for increasing successfully riverside rehabilitation area of oil palm plantation.

Farmland birds occupying forest clear-cuts respond to both local and landscape features

Agricultural landscapes have changed fast in Europe, which has led to steep declines in farmland biodiversity. While this has differentially impacted “farmland species”, some of these seem to be able to use alternative man-made open habitats in forests, such as forest clear-cuts and powerline rights-of-way. We investigated the use of clear-cuts by two historically declining farmland birds, the Yellowhammer (Emberiza citrinella) and the Red-backed Shrike (Lanius collurio), to determine both local and landscape habitat characteristics of clear-cuts used for breeding. Among 101 clear-cuts visited in Scania, southern Sweden, 27% were occupied by Yellowhammers and 12% by Red-backed Shrikes. Yellowhammer occurrence in clear-cuts was positively related to local spruce cover (the planted tree species). There was also an interaction between clear-cut size and the proportion of farmland in the landscape, such that the positive effect of the proportion of farmland nearby was stronger for larger clear-cuts. Red-backed Shrike occurrence was positively related to clear-cut size and the local presence of piles of forest residues (tops and branches). The relation between occurrence and the proportion of clear-cuts in the landscape was positive for small clear-cuts and negative for larger ones. Yellowhammers and Red-backed shrikes are affected by both the local habitat structure in the clearcut and on the composition of the surrounding landscape, most likely because they use the clear-cut for nesting and the surroundings as complementary feeding habitat. To what extent clear-cuts as complementary breeding habitat to farmland may contribute to the conservation of Yellowhammers and Red-backed shrikes, as well as other farmland birds, is a promising path for future investigations.

Accelerating forest tree breeding by integrating genomic selection and greenhouse phenotyping.

Breeding forest species can be a costly and slow process because of the extensive areas needed for field trials and the long periods (e.g., five years) that are required to measure economically and environmentally relevant phenotypes (e.g., adult plant biomass or plant height). Genomic selection (GS) and indirect selection using early phenotypes (e.g., phenotypes collected in greenhouse conditions) are two ways by which tree breeding can be accelerated. These approaches can both reduce the costs of field-testing and the time required to make selection decisions. Moreover, these approaches can be highly synergistic. Therefore, in this study, we used a data set comprising DNA genotypes and longitudinal measurements of growth collected from a population of Populus deltoides W. Bartram ex Marshall (eastern cottonwood) in the greenhouse and the field, to evaluate the potential impact of integrating large-scale greenhouse phenotyping with conventional GS. We found that the integration of greenhouse phenotyping and GS can deliver very early selection decisions that are moderately accurate. Therefore, we conclude that the adoption of these approaches, in conjunction with reproductive techniques that shorten the generation interval, can lead to an unprecedented acceleration of selection gains in P. deltoides and, potentially, other commercially planted tree species.

Mineral fertilization and soil depth slightly affected aggregate structures despite significantly altered microbial properties in surface forest soils

Purpose: Successive mineral fertilization might have side effects on soil environmental quality, such as aggregate structure, contamination, and enzyme activity. To gain a more comprehensive understanding of the influences of mineral fertilization on biotic and abiotic properties of forest soils, we investigated the effects of successive nitrogen and phosphorus fertilization on physical structures, contaminant contents, and microbial communities of forest soils with different sampling depths. Materials and methods: Mineral nitrogen (N) and phosphorus (P) were applied, alone or together, at different rates to provide nutrients to economic tree species (Chinese fir) in a forest plantation since 2011. Surface soil samples were taken at different sampling depths, and soil aggregate, contaminant content, and microbial properties were determined and comprehensively linked. Results and discussion: Our results showed that successive fertilization, sampling depths, and their interactions had negligible impacts on soil aggregate ratios and cadmium (Cd) and arsenic (As) contents. Contrastingly, soil β-glucosidase, phosphate, and fungal and actinomycetal biomass were significantly affected by the mineral fertilization, and sampling depth was a key factor determining the responses of microbial communities to the mineral fertilization. Conclusions: In the surface (0–20 cm) soils, abiotic properties had resistance to different fertilization and sampling depths, but biotic properties were markedly or significantly affected by the mineral fertilization or sampling depths. Simultaneously, sampling depths should be considered to reveal the impacts of managements on microbial properties in the surface forest soils.

Evolutionary legacy of a forest plantation tree species (Pinus armandii): Implications for widespread afforestation.

Many natural systems are subject to profound and persistent anthropogenic influence. Human‐induced gene movement through afforestation and the selective transportation of genotypes might enhance the potential for intraspecific hybridization, which could lead to outbreeding depression. However, the evolutionary legacy of afforestation on the spatial genetic structure of forest tree species has barely been investigated. To do this properly, the effects of anthropogenic and natural processes must be examined simultaneously. A multidisciplinary approach, integrating phylogeography, population genetics, species distribution modeling, and niche divergence would permit evaluation of potential anthropogenic impacts, such as mass planting near‐native material. Here, these approaches were applied to Pinus armandii, a Chinese endemic coniferous tree species, that has been mass planted across its native range. Population genetic analyses showed that natural populations of P. armandii comprised three lineages that diverged around the late Miocene, during a period of massive uplifts of the Hengduan Mountains, and intensification of Asian Summer Monsoon. Only limited gene flow was detected between lineages, indicating that each largely maintained is genetic integrity. Moreover, most or all planted populations were found to have been sourced within the same region, minimizing disruption of large‐scale spatial genetic structure within P. armandii. This might be because each of the three lineages had a distinct climatic niche, according to ecological niche modeling and niche divergence tests. The current study provides empirical genetic and ecological evidence for the site‐species matching principle in forestry and will be useful to manage restoration efforts by identifying suitable areas and climates for introducing and planting new forests. Our results also highlight the urgent need to evaluate the genetic impacts of large‐scale afforestation in other native tree species.

Flowering and fruiting phenology of Acer laurinum (Sapindaceae) at ex-situ conservation site

Acer laurinum (Sapindaceae) is a threatened tree plant species with least concern (LC) status. There is only limited information regarding the phenology of flowering and fruiting of this species. Along with the increasing damage to its natural habitat, not surprisingly, in the future, this status will be more threatened. Therefore, it is necessary to study the phenology cycle of this species for the purposes of further development. In order to achieve a continuous and sequenced observation, the study was conducted in a built environment, one of an ex-situ plant conservation site. Furthermore, the study also conducted to analyze the effect of the microclimate on this cycle. The study conducted with A. laurinum tree specimen planted in 1986 at Cibodas Botanic Gardens, Cianjur, West Java. The study used descriptive quantitative analysis based on the exploratory-inventory observation of flowering and fruiting phase data, and the microclimate conditions assessed from 2014 to 2015. The results showed that the flowering and fruiting occurred from early January to April, and at the end of the year, from September to December, along with the high level of precipitation of the periods. Even the other microclimate units also dynamically changed, but there were no significantly affected the flowering and fruiting phenology. The results suggested that these periods can be conducted seeds harvesting and (re)stock in order to achieve maximum results.

Structure and composition of field margin vegetation in the rural-urban interface of Bengaluru, India: a case study on an unexplored dimension of agroecosystems.

Field margin vegetation (FMV) refers to the plant community in the interface between agriculture and natural environments. Substantial work has been carried out on the management of field margins in European countries with the aim of conserving field-level biodiversity and enhancing agronomic benefits. India, instead, is lagging behind in the assessment of FMV and formulating subsequent management strategies for biodiversity conservation at the field boundaries. This study is a first step to better understand the structural and functional dimensions of field margin vegetation along an agricultural transformation gradient near the megacity of Bengaluru, India. Empirical field studies along with the detection of vegetation change using remote sensing and geo-informatics technique were used to record information on field margin vegetation. The phytosociological study, revealed a total of 81 species, comprising 29 species of trees, 21 shrubs and 31 herbs at the field margins of six selected villages of northern Bengaluru. Randomly selected 355 field boundaries were delineated from high-resolution Worldview 3 images for the year 2018 and from Google Earth images for the year 2004-2005. The FMV area was around to 85.40ha in 2004-2005 but declined to 76.69ha in 2017-2018. The survey also indicated that local farmers have in-depth ecological knowledge on the importance of FMV in ensuring a sustainable flow of resources within the agricultural landscape. The results demonstrate that rural and transition zones of the study area have higher dominance of planted tree species on the margins, whereas urban zone exhibits comparatively uniform dominance for all species. Our study also highlights the need for conservation of FMV to ensure agroecosystem health as a prerequisite for sustainable socioecological development.

Fire sensitivity of broadleaf tree species in plantations of Kurdistan, Iran

To better manage wildfires and plantations in Kurdistan, native tree species commonly used in planting and reviving forests such as Quercus brantii Lindl., Q. infectoria Olivier, Q. libani Olivier, Pistachio atlantica Desf., Fraxinus rotundifolia Vahl, and Robinia pseudoacacia L. were evaluated and compared in terms of fire sensitivity and fire resistance. To determine fire sensitivity, indices such as the flammability index, ignition time, flame durability, moisture content, carbonized surface, mass reduction, bulk density, as well as dry weight of wood, bark, and leaves were used. The data were subjected to ANOVA. The means obtained, after examining homogeneity or heterogeneity of the variances, were compared using parametric and nonparametric comparison tests. There was a significant difference at the level of 5%. Based on the analysis of these indices, the species could be divided into three groups: species sensitive to fire such as Robinia pseudoacacia, species moderately sensitive to fire such as F. rotundifolia, and species relatively resistant to fire, including Q. brantii, Q. libani, Q. infectoria, and P. atlantica.

Diversity and Aboveground Carbon Sequestration Potential of On-Farm Agroforestry Trees/shrubs Species in Rajaf County-South Sudan

Agroforestry (AF) trees have the potentials to sequester carbon in most farming systems especially in the face of the current climate change. The objective of this study was to estimate the diversity, abundance, and aboveground carbon sequestration potential of onfarm tree species in four different sites, Tokiman, Gumbo, Kolye West, and Kolye East with various agroforestry practices in Rajaf County, South Sudan. Three hundred and fifty-five AF trees were inventoried by non-destructive methods for diameter at breast height (DBH), height (H) and Crown width (CR) variables. Aboveground biomass analyzed using allometric models was converted to carbon stocks. The Shannon-Weiner indices for the AF sites indicated that C. limon, M. indica and P. guajava were more diverse in Tokiman and Gumbo sites. T. grandis was more diverse in Kolye East and Kolye West, with S. siamea only diverse in Kolye West. The diversity analyses also showed low values of (H’) for Gumbo and Tokiman as compared to those calculated for Kolye West and Kolye East. In addition, high levels of aboveground carbon sequestration were observed in Gumbo and Kolye East sites where tree species were relatively abundant. Kolye West, on the other hand, had very few but highly dominant AF tree species while Tokiman Islands with the most planted tree species had a rare agro-ecology that contributed less or nearly zero to aboveground carbon sequestration.

Effect of planting density and tree species selection on forest bioenergy systems: tree growth, nutrient storage and wood chemical properties

AbstractThis study based on woody biomass was conducted under an experimental design of randomized complete blocks with two species, Eucalyptus saligna and Eucalyptus tereticornis, in three planting densities, 5000 trees ha−1, 10 000 trees ha−1, and 20 000 trees ha−1. Data were collected at 3, 12, and 24 months and growing relationships were analyzed. Adobe ground biomass, soil carbon reserve, plant issue nutrients, and woody biomass were determined. Results showed statistically significant differences between species in biomass production, obtaining values from 36.80 to 117.42 Mg ha−1 in E. tereticornis and 36.10 to 107.67 Mg ha−1 in E. saligna. Optimum planting density for both species proved to be 10 000 trees ha−1, which showed better biomass accumulation and growth performance in addition to lower mortality, and less impact on productivity. Regarding soil nutrition, it was determined that as crop density increased, the loss of nutrients (N, P, K, Ca) increased, with a loss of up to 33% in 24 months in the density of 20 000 trees ha−1. For both species, the treatment of 10 000 trees ha−1 provided the highest concentration of organic matter in the top 20 cm of soil. Finally, wood chemical aspects did not show differences in the properties with any treatment. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

Edaphic factors determining the colonization of semiarid mine tailings by a ruderal shrub and two tree plant species: Implications for phytomanagement

Phytomanagement has been considered a feasible technique to decrease the environmental risks associated to mine tailings and its implementation relies on a suitable plant species selection. The goal of this study was to identify the edaphic factors, including microbiology, affecting the establishment of plant species with contrasting growth patterns during the phytomanagement of mine tailings. For this purpose, a comprehensive rhizosphere characterization was performed in an early ruderal colonizer, Zygophyllum fabago and two late successional tree species, Pinus halepensis and Tetraclinis articulata, growing at a mine tailings pile in southeast Spain. The neutral pH of the tailings determined low 0.01 M CaCl2 metal extractable concentrations (e.g. <10 μg kg−1 Pb and Cd). Thus, other soil properties different from metal concentrations resulted more determining to explain plant establishment. Results revealed that Z. fabago selectively colonized tailings patches characterized by high salinity (3.5 dS m−1) and high silt percentages (42%), showing a specific halotolerant rhizospheric microbial composition, such as the bacterial Sphingomonadales and Cytophagales orders and the fungal Pleosporales and Hyprocreales orders. The two tree species grew at moderate salinity areas of the tailings pile (1.7 dS m−1) with high sand percentages (85%), where Actinomycetales was the most abundant bacterial order (>10% abundance). The contrasting mycorrhizal behaviour of both tree species (ectomycorrhizal for P. halepensis and endomycorrhizal for T. articulata) could explain the differences found between their fungal rhizospheric composition. In terms of phytomanagement, the selective plant species colonization following specific soil patches at mine tailings would increase their biodiversity and resilience against environmental stressors.

BASIDIAL MUSHROOMS-XYLOTROPHES OF GREEN PLANTATIONS OF TREES OF ODESA

Problem. Species diversity of basidial xylotrophic fungi and their effect on the condition of the wood species associated with them.Aim. Investigation of the xylotrophic mushrooms of the green plantations of trees of Odesa and evaluation of their indicator significance.Methods. Studies of basidial xylotrophics were carried out in 2010-2020. Mushrooms were collected on trees, tree fallout (branches) and on stumps within the city of Odesa, in particular in the parks named after Shevchenko, Pobedy, Savitskyi, Diukovskyi, on the coastal slopes and on the streets of the city, where the oldest age group of tree plants is most widely represented. For this, the method of route studies was used. The description of the identified species was carried out according to the conventional method. When describing fruit bodies (basidiocarps), attention was paid to their shape and size, texture, surface character, color, odor, type of hymenophore. Gif staining was performed with a standard set of reagents and dyes (5-7% KOH or NaOH, Meltzer reagent, iron sulfate, Congo red dye, etc.). A total of about 50 samples of basidiomycetes have been collected. Well-known determinants were used to identify them. Indicative significance of basidial xylotrophics (disturbance of the state tree stand) was evaluated according to the method of O.A. Blinkova.Main results. The total number of the species of basidial xylotrophs found in green plantations of trees of Odesa is 27. They belong to two classes, 6 orders, 13 families and 22 genera. The detected xylotrophs were associated with 19 species of tree plants. It is shown that in the Mycocenoses of green plantations in Odesa, indicators of strong damage of wood species prevail, including mechanical ones, which leads to the thinning of tree stand and its fragmentation. The results obtained can be used for the timely phytosanitary activities in parks and on the city streets.Conclusions: The deterioration of the ecological parameters of the growth areas of the tree species in the green plantations of Odesa leads them to the oppression and settlement by xylotrophic mushrooms.Keywords: wood destructive fungi; species composition; indicator significance; green plantations of trees; Odessa.