Casuarina Research Articles

Use of Spinning Roller in Cylindrical Densification; Spring back in Black Poplar, Larch and Cedar of Lebanon after Densification

Wood materials have been the solution to many needs throughout history due to their unique positive properties. By improving the properties of wood materials, their areas of use can be expanded and ensured that they are preferred. The densification process is one of the studies carried out to improve wood material properties. With densification, the physical and mechanical properties of the wood material are improved. There are many different methods used for densifying wood materials. While the densification process brings many positive properties to the wood material, an undesirable situation such as spring-back after the process is the negative side of the densification process. In this study, black poplar (Populus nigra L.), larch (Pinus nigra Arnold) and cedar of Lebanon (Cedrus libani A.Rich.) trees were shaped into cylinders on a lathe. After that, densification processes were carried out on the lathe machine using the spinning roller designed and manufactured for this purpose. Densification processes were carried out at 0.081, 0.121, and 0.202 mm/rev feed, at 200 and 400 rev/min, and 0.5 and 1 mm densification depths. The spring-back rates after densification in three different types of cylindrical wood materials were investigated. Theoretical and experimental spring-back amounts of test specimens whose surfaces were densified under different densification conditions were interpreted. When evaluated in general, the highest densification rate was obtained in black poplar wood species, 0.081 mm/rotate feed, 200 rpm spindle speed and 1 mm depth of densification. The lowest spring-back ratio was obtained in larch tree species, 0.121 mm/rotate feed, 400 rpm spindle speed and 1 mm depth of densification. The highest densification percentage was obtained in black poplar tree species, and the lowest in larch tree species. The lowest percentage of spring-back was obtained in the larch tree species and the highest in the black poplar tree species.

Introduction pages, NBHA-CN 51(3), 2023

The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 3, Volume 51, 2023 represent new exciting research in different topics of life science, respectively in plant science, horticulture, agronomy, crop science, and forestry. Among the interesting articles we invite you to find news about: Comparison of the potential of extracts from the flower, fruit pulp, and seed of Cassia fistula L. on MCF-7 breast cancer cell growth and cell migration; Evaluation of anticancer activity of Plumbago indica root extract on cervical HeLa cancer cells; Metabolome and transcriptome analyses reveal the colouring mechanism of red honeysuckle (Lonicera japonica Thunb.); Ethylene modulates root growth and mineral nutrients levels in trifoliate orange through the auxin-signaling pathway; Green nanotechnology for plant bacterial diseases management in cereal crops: a review on metal-based nanoparticles; Physiological responses of coffee (Coffea arabica L.) plants to biochar application under water deficit conditions; Gene mining and functional analysis related to maize (Zea mays L.) seed size; Phytochemical properties, antioxidant potential and fatty acids profiling of three dragon fruit species grown under sub-tropical climate; Chemical composition and anti-inflammatory effect of Phellodendron amurense Rupr. stem bark extract; Ecotype effects on photosynthesis performance using A/PFFD among Pinus nigra Arn.; Assessment of herbaceous vegetation classification using orthophotos produced from the image acquired with unmanned aerial systems.

Analysis of Radial Growth Dynamics of Pinus Nigra Subsp. Pallasiana (Lamb.) Holmboe in Different Parts of the Slope Profile

The results of the research of radial growth of Pinus nigra trees growing in the foothill-forest-steppe zone (in Belogorosk district) with continental climate type of the Crimean Peninsula are presented. The research was con[1]ducted to evaluate the influence of the location of the growth site on the local slope on the total width of the annual ring. Geomorphologically, the sampling points were located along the profile of a gentle convex slope of eastern exposure. Wood samples were collected at sites within the lower, middle and watershed parts of the slope, as well as at the top of the Biyuk-Karasu River watershed. Generalised tree-ring chronologies were obtained for each part of the slope, the average age of the chronologies being 50 years. As a result of the research, a synchronism in growth dynamics of trees growing in the lower part of the slope and in the watershed was established; the radial growth of Pinus nigra trees in the middle parts of the slope reacts the earliest to the influence of environmental factors. The reaction lag of radial growth in the watershed part of the slope is about 11 years. Analysis of the constructed chronologies shows that over the past 50 years, the radial growth is comparable to the dynamics of meteorological parameters. The analysis of correlations of the obtained chronologies with the values of average monthly air temperatures and annual precipitation according to the data of the Simferopol meteorological station was carried out. For the lower and middle parts of the slope, as well as for the watershed, the amount of precipitation is more significant than air temperature. Correlations have been established between the radial growth index of the lower and middle parts of the slope, as well as watershed and the sum of precipitation in May, and the summer months of both the current and previous years. For Pinusnigra trees growing on the watershed parts of the slope, air temperatures of summer months of the current and previous year are more significant. The established close relationship can be used to reconstruct climatic conditions of Pinus nigra trees.

Türkiye’nin kuzeybatısındaki bir plantasyonda yerli ve egzotik çam türlerinin ibrelerinde görülen fungal endofitler

The endophytic fungi present in needles of Pinus sylvestris, Pinus pinaster, Pinus nigra, Pinus taeda and Pinus radiata were investigated in Kerpe Research Forest, İzmit in 2016. Ten trees of each pine species were sampled systematically. Previous years green needles were sampled from the lower part of the canopy, from two equally spaced positions around the tree. Each needle was surface sterilized and cut into 0.5 cm sections then individually placed onto malt extract agar plates. DNA was ex-tracted from reprensentative seven isolates and amplified using primers ITS1 and ITS4 targeting the nuclear 5.8S rDNA gene and the two ITS regions flanked between 18S and 28S rDNA genes. Amplicons sequenced in both directions using the univer-sal fungal primers ITS1 and ITS4. Isolations from a total of 1000 needles (200 from each pine species) yielded 750 fungal isolates. Pestalotiopsis funerea (Desm.) Steyaert was isolated at the highest frequency followed by Acremonium sp., Cladio-sporum sp. and Cyclaneusma minus.

Ecotype effects on photosynthesis performance using A/PFFD among Pinus nigra Arn.

This study aimed to provide insights on intraspecific variability of photosynthesis performance of 19 provenances of black pine planted in a common garden. The experiment was conducted in an experimental trial located at Souiniet (the southern limit of its range) Photosynthetic capacity char­acterized by light-saturated net photosynthetic rates, associated light compensation points and apparent quantum yield was monitored by measuring the response of leaf gas exchange to light levels. Amax was the highest in provenances Puget Theniers (nigra ssp), Saint-Guilhem (salzmanni ssp), Marghese and les barres (laricio ssp). The lowest value was recorded in Olette of the subspecies salzmanni. Needles from two provenances Crimea (pallasiana ssp) and Les Barres (ssp laricio) revealed the highest apparent quantum yield (ɸ), followed by Brougatlès Ales (salzmanni ssp), Trenta Coste (ssp laricio), Les barres and Puget Theniers (nigra ssp). The lowest apparent quantum Yield was recorded in Laricio subspecies (Cosenza; Les barres and Bois frerot). The highest value of dark respiration (Rd) was shown in provenance Les barres (laricio ssp), while Grancia and Tavola of the laricio subspecies reported the lowest one. Provenances Tavola (laricio ssp) and Puget Theniers (nigra ssp) exhibited the highest LCP. The provenance Crimée (pallasiana ssp) and Aspromonto (laricio ssp) recorded the lowest values. The maximum values of photosynthesis are positively correlated with the total chlorophyll contents and Leaf Mass area. Our study illustrates that Photosynthesis performance showed a difference between 19 provenances of black pine; it seems that black pine photosynthetic performance is eco-typical independent.

Local site conditions reduce interspecific differences in climate sensitivity between native and non-native pines

Two European pine species, Pinus sylvestris and Pinus nigra, are experiencing dieback as a result of the increasing frequency and intensity of extreme climatic events. Recent species distribution models predicted shrinkage of ecological niches in the near future and shifted their habitat range towards the northeast. Consequently, P. sylvestris may contract its range and P. nigra may expand in Central Europe. To test whether native pine species have an advantage over introduced pine species in acclimation to a novel climate in Central Europe, we investigated the climate sensitivity and vitality of P. sylvestris, P. nigra and P. rigida. We sampled mature stands of each pine species at three sites in Central Europe, for which we determined climate–growth relationships: temporal stability of temperature and precipitation correlations with tree-ring width and resilience indices. Based on remote sensing data, we assessed differences in surface reflectance and photosynthetic activity obtained from the normalised difference vegetation index (NDVI). Our analyses revealed that the climate sensitivity and surface reflectance of pines are not due to their nativeness in Central Europe but better explained by local site conditions. The specificity and variability of drought events may determine both the homogeneous and diverse susceptibility of species to a negative water balance. Therefore, the character of future climatic extremes seems to be the key to understanding the acclimation of native and non-native pine species in Central Europe. Because our study do not provide evidence of the superiority of non-native pine species over P. sylvestris, and the potential impacts of introduced species on local habitats seem poorly understood in the face of climate change, we urge particular caution in introducing species with unrecognized invasive potential.

The potential of using the Blue Intensity parameter to assess the climate response of radial tree growth on the Crimean peninsula

The results of assessing the climate signal contained in the width of tree rings and the indicator of optical density of wood (Blue Intensity) of related species of pine trees – black (Pinus nigra Arnold) and Pitsunda (Pinus brutia Ten) growing on the southern coast of the Crimean peninsula are presented. The influence of the cumulative effect of moisture deficiency on the radial growth and lignification processes of late wood of the studied conifer species is shown. A specific reaction of P. nigra in high mountain areas to conditions of prolonged drought was revealed. The prospects for using the Blue Intensity indicator for dendroclimatic studies on the territory of the Crimean Peninsula have been demonstrated.

Historical overview of the Deliblato sands afforestation

Deliblato Sands is one of the largest sandy areas in Europe. Given that developing of vegetation on the sand is a slow process, followed by human activities that devastate the plant cover (grazing, deforestation), the free-moving sand on Deliblato Sands exited until the 18th century. Unbound sand hindered the development of agriculture in the entire southern Banat region, so it was necessary to start a more intensive process of restraining sand masses. The afforestation of this area began in 1818 and is still ongoing. In the process of afforestation, nine periods can be recognized that differ in relation to afforestation/reforestation techniques, the choice of species or the organizational structure of the forestry units (and countries) of the area of Deliblato Sands belonged throughout history.The most significant results in the binding of free moving sand were achieved by the application of black locust (Robinia pseudoacacia L.) seedlings with juniper scrub (Juniperus communis L.) laid down on open sandy areas and sowing different species of grass between the rows of seedlings. This technique has been applied since the IV afforestation period (1878-1898). The largest areas were afforested in the V period (1898-1918), when parts of Deliblato Sands were formally protected for the first time in history as areas of importance for the preservation of biodiversity. The species most used in afforestation are black locust (Robinia pseudoacacia L.), Scots pine and black pine (Pinus sylvestris L., Pinus nigra J. F. Arnold), poplars (Populus sp.), and some shrubby (e.g. Juniperus virginiana L.) and herbaceous species (e. g. Ammophilla arenaria (L.) Link, Festuca vaginata Willd., Leymus arenarius (L.) Hochst., Carex arenaria L.). Today, Robinia pseudoacacia L. is most common tree species on Deliblato Sands and it occupies almost a third of the entire area.

Application of a Soil Quality Index to a Mediterranean Mountain with Post-Fire Treatments

In Mediterranean areas, fire has increased soil degradation and erosion. For this reason, the application of soil quality indices can help to determine soil recovery and degradation levels. By using a multiparameter soil quality index fitted to undisturbed forest soils, we can show the right information on soil functionality. In this study, the objectives were to evaluate soil functionality after suffering a fire, to subsequently treat with various soil treatments (wood mulching), and then check a soil quality index (SQI) to assess the soil quality recovery in burned Pinus nigra stands. For this purpose, a burned area was selected in the Cuenca Mountain range (Spain) under a Mediterranean climate. Experimental plots were established in the study area, with three slope gradients and applying three methods of covering soil using: (1) wood chips; (2) piles of branches; and (3) trunks of contour-felled logs. The experiment was conducted for 4 years. Results showed that the properties of soil were enhanced under wood chips and logs as a surface-covering material, and in a short time (less of 3 years). In consequence, the values of the SQI index were higher after applying these two treatments, thus reflecting the effectiveness of the SQI for monitoring post-fire recovery.

Effect of silane-siloxane based water-repellent impregnant on the dimensional stability of some wood species

A silane-siloxane based water-repellent substance (S-WR) was used as an impregnation material for Scots pine (Pinus sylvestris L.), black pine (Pinus nigra Arnold), sessile oak (Quercus petraea Liebl.), and cedar (Cedrus libani A. Rich). In the impregnation process, the immersion method was carried out for various periods (30 min, 3 h, and 24 h). Following impregnation, physical properties of the wood (retention, contraction, expansion, water intake rate, specific gravity, etc.) were determined. The retention was highest in sessile oak wood (0.96%) and lowest in black pine wood (0.24%). The highest specific gravity value was found in stemless oak (0.86 g/cm³) impregnated for 24 h, and the lowest air-dry specific gravity value was found in Scots pine (0.40 g/cm³) impregnated for 30 minutes Absolutely dry (0% humidity) specific gravity was highest in sessile oak for 24 h (0.83 g/cm³). Shrinkage was highest in the sessile oak control sample (13.5%). The expansion amount was highest in the cedar wood control sample (17.5%) and lowest in sessile oak wood (1.66%). The highest water uptake rate (SAO) was determined in Scots pine wood at 96 h (105%), and the lowest in sessile oak wood in 24 h (8.80%). In summary, silane-siloxane based water-repellent impregnation material was found to be effective in providing dimensional stability in wood.

Carbon Stock of Australian pine (Casuarina equisetifolia) in Cemara Sewu Beach Jetis Cilacap

Global warming is the increase in temperature in the atmosphere, sea and land. The increase in carbon or greenhouse gases is one of the causes of global warming. One solution to reduce the presence of greenhouse gases is to increase carbon stock. Beach is home to the richest ecosystems in the world and many components of the vegetation that store large amounts of carbon stock. Carbon compounds in the atmosphere are absorbed and metabolized. The metabolic products are stored in tree biomass. One of the trees that can be relied on as a stock carbon is those located at Cemara Sewu Beach, Cilacap. Cemara Sewu Beach is one of the beach that has a relatively large amount of stored carbon potential. The purpose of this study was to determine the carbon stored in several types of trees at Cemara Sewu Beach. The method used in this study is a survey method with purposive sampling using without destroying. The sampling of Australian pine tree stands is grouped into certain diameter class. The coastal area was made into three research stations and each study was made into 5 replicated plots measuring 20 m x 20 m and placed on a transect line with a distance of 5 meters each. All of the Australian pine were plotted as samples. The independent variable in this study was the diameter class of Australian pine, while the dependent variable was carbon stock. The main parameters observed were tree density, trunk diameter and the number of individuals for each tree species were calculated. The data obtained were analyzed using Analysis of Variance (ANOVA) followed by the Least Significant Difference (LSD) test with an error rate of 5%. The results of the research on the diameter class of Australian pine greatly affect the presence of biomass and carbon stock. The results obtained that carbon stocks in diameter class 15-20 store 74,914 ton.ha-1, diameter class 21-25 as many as 164,599 ton.ha-1, diameter class 26-30 as many as 270,372 ton.ha-1, diameter class 31-35 store stocks carbon 462,478 ton.ha- 1 and in the diameter class 36-40 store as much as 462,478 ton.ha-1. The larger the class diameter, the greater the carbon stock produced. The diameter class of Australian pine stands has a relationship between biomass and carbon stock, and has an exponential relationship.

Artificial inoculation and susceptibility of Pinus armandii to Dothistroma septosporum

AbstractDothistroma needle blight (DNB) is a serious needle disease of conifers that primarily affects pine species (Pinus spp.). Dothistroma septosporum is one of the DNB pathogens that has a diverse range of host species excluding Pinus armandii. In 15 inoculated P. armandii seedlings, D. septosporum acervuli were observed in 43 infected needles of ten seedlings with a mean disease severity of 1.11% at 25 weeks after inoculations, demonstrating the potential of D. septosporum to cause symptoms on the needles of P. armandii via artificial inoculation. The disease severity of P. armandii was similar to the positive control, Pinus nigra (median 0.75 for P. armandii to 0.70 for P. nigra), thus, P. armandii acts under artificial conditions as a susceptible host species.

Simultaneous Improvement of Surface Wettability and UV Resistance of Wood with Lignin-Based Treatments.

Recent advancements in wood modification aim to enhance the inherent qualities of this versatile biological material, which includes renewability, ease of processing, and thermal insulation. This study focuses on evaluating the effectiveness of lignin as a protective agent for less durable wood species, namely, Pinus nigra and Fagus sylvatica L. The impregnation of wood with three various forms of lignin, such as kraft lignin, acetylated kraft lignin, and lignin nanoparticles, was carried out using the vacuum technique at room conditions. The results showed that the treatments significantly improve the hydrophobicity of wood surfaces, particularly in pine wood, and provide protection against UV ageing. Additionally, the treatments contributed to the stabilisation of moisture content at different humidity levels. Although slight colour variations were observed, their impact on the visual appearance was minimal, and the thermal analysis confirmed enhanced thermal properties. Additionally, plasma treatment further enhanced hydrophobicity after treatments, offering potential benefits in terms of moisture resistance and durability. The findings of this study highlight the promising effects of lignin-based treatments on wood properties, providing sustainable solutions for wood protection in various sectors. However, further optimisation is needed to fully explore the potential of lignin and lignin nanoparticles.

A multi-proxy framework to detect insect defoliations in tree rings: a case study on pine processionary

Assessing and reconstructing the impacts of defoliation caused by insect herbivores on tree growth, carbon budget and water use, and differentiating these impacts from other stresses and disturbances such as droughts requires multi-proxy approaches. Here we present a methodological framework to pinpoint the impacts of pine processionary moth (Thaumetopoea pityocampa), a major winter-feeding defoliator, on tree cover (remote-sensing indices), radial growth and wood features (anatomy, density, lignin/carbohydrate ratio of cell walls, δ13C and δ18O of wood cellulose) of drought-prone pine (Pinus nigra) forests in north-eastern Spain. We compared host defoliated (D) and coexisting non-defoliated (ND) pines along with non-host oaks (Quercus faginea) following a strong insect outbreak occurring in 2016 at two climatically contrasting sites (cool-wet Huesca and warm-dry Teruel). Changes in tree-ring width and wood density were analyzed and their responses to climate variables (including a drought index) were compared between D and ND trees. The Normalized Difference Infrared Index showed reductions due to the outbreak of –47.3% and –55.6% in Huesca and Teruel, respectively. The D pines showed: a strong drop in growth (–96.3% on average), a reduction in tracheid lumen diameter (–35.0%) and lower lignin/carbohydrate ratios of tracheid cell-walls. Both pines and oaks showed synchronous growth reductions during dry years. In the wet Huesca site, lower wood δ13C values and a stronger coupling between δ13C and δ18O were observed in D as compared with ND pines. In the dry Teruel site, the minimum wood density of ND pines responded more negatively to spring drought than that of D pines. We argue that multi-proxy assessments that combine several variables have the potential to improve our ability to pinpoint and reconstruct insect outbreaks using tree-ring data.

Secretome analysis revealed that cell wall remodeling and starch catabolism underlie the early stages of somatic embryogenesis in Pinus nigra.

Somatic embryogenesis is an efficient mean for rapid micropropagation and preservation of the germplasm of valuable coniferous trees. Little is known about how the composition of secretome tracks down the level of embryogenic capacity. Unlike embryogenic tissue on solid medium, suspension cell cultures enable the study of extracellular proteins secreted into a liquid cultivation medium, avoiding contamination from destructured cells. Here, we present proteomic data of the secretome of Pinus nigra cell lines with contrasting embryogenic capacity, accounting for variability between genotypes. Our results showed that cell wall-related and carbohydrate-acting proteins were the most differentially accumulated. Peroxidases, extensin, α-amylase, plant basic secretory family protein (BSP), and basic secretory protease (S) were more abundant in the medium from the lines with high embryogenic capacity. In contrast, the medium from the low embryogenic capacity cell lines contained a higher amount of polygalacturonases, hothead protein, and expansin, which are generally associated with cell wall loosening or softening. These results corroborated the microscopic findings in cell lines with low embryogenic capacity-long suspensor cells without proper assembly. Furthermore, proteomic data were subsequently validated by peroxidase and α-amylase activity assays, and hence, we conclude that both tested enzyme activities can be considered potential markers of high embryogenic capacity.

Analysis of the Climate Signal in Subannual Width Measurements of Pinus nigra Tree Rings in Kastamonu Province, Turkey

Analysis of the Climate Signal in Subannual Width Measurements of Pinus nigra Tree Rings in Kastamonu Province, Turkey

Создание лесных культур сосны крымской (Pinus pallasiana D. Don) на бугристых песках в степной зоне России

Forest crop cultivation of Crimean pine (Pinus pallasiana D. Don) was implemented in 2009–2020 on sandy and sand included soils in the steppe zone of the European part of Russia. During the analysis of the reasons for the low efficiency of reforestation, the authors proposed the hypothesis that the rules of planting recommended for Scots pine relative to the depth of rooting may not be acceptable for Crimean pine. The purpose of the work is to substantiate the necessity and the most optimal value of deepening the root collar of Crimean pine seedlings on hilly sands. Experimental forest cultures were planted in 2017. The depth of the plant collar relative to the soil surface was tested at 0, 2, 4, 6 cm, and until the seedling’s foliated part. The reference group was created by machine cultivation, which required a rooting depth of 6 cm or more. In the case of hand cultivation, the variants with planting depths of 2 and 4 cm had the highest rates of plant survival (94.2–94.6 % in the first year), plant safety (67.0–94.6 % in the fourth year), and their most even distribution over the silvicultural area (variation coefficient (υ) at 6.6–28.8 %). The lack of deepening and very deep planting by 6 cm led to a decrease in plant survival and preservation by 7.6–18.6 % with an increase in the range of the variation coefficient (υ, 10.2–60.6 %). The mechanized planting with a root collar depth over 6 cm gave the lowest number of preserved plants (58.4 % in the first year, 32.7 % in the fourth year), and the greatest range for the variation coefficient (υ, 30.5–70.1 %). An analytical equalization of the density of age dynamics showed that the predicted density would not reach the normative value with low and very deep planting. The established statistically significant differences in the survival rate of forest cultures throughout the observation period (tf = 2.12–4.38> t05 = 2.12–2.45) indicated the expediency of deepening the root collar. The optimal value is 2–4 cm, but until the seedling’s foliated part. For citation: Turchina T.A., Bannikova O.A. Creation of Forest Cultures of Crimean Pine (Pinus pallasiana D. Don) on the Hilly Sands in the Steppe Zone of Russia. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 76–92. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-76-92

Non-native tree species growth characteristics inventoried three decades after planting in the Danube Lowland

Abstract This paper presents non-native (NN) coniferous and deciduous tree species growth and vitality assessment on experimental research plots established in 1980, 1982 and 1985 in the Danube Lowland over an extended time period. For NN coniferous tree species, Douglas fir, grand fir and eastern white pine reached significantly higher values of diameter at breast height (dbh) and height (H) than Austrian pine. For NN deciduous tree species markedly higher values of H and dbh for black walnut compared to sweet chestnut and red oak were recorded. Damage observed in larger extent on examined NN tree species stands included illegal removal of top of stem for grand fir and presence of necrosis on trunks of sweet chestnut. Comparison of NN coniferous and deciduous tree species growth with native reference tree species showed that NN Douglas fir, grand fir, eastern white pine, red oak and black walnut were capable to achieve similar or even higher values of assessed parameters than native reference tree species. The results suggest, that cultivation of NN coniferous, including Douglas fir, eastern white pine, as well as NN deciduous tree species, including red oak and black walnut in Danube Lowland could contribute to diversification and stabilisation of wood production potential of local forest formations.

Short-Term Effects of Prescribed Burn Seasonality on the Understory in a Pinus nigra Arnold subsp. salzmannii (Dunal) Franco Mediterranean Forest

Worsening climate change and increasing temperatures generate more sever and extended wildfires, raising concerns about ecosystem services. Prescribed burns (PB) are used to reduce forest fuel loads. Improving knowledge regarding the vegetation response after PB is essential for generating common points for monitoring ecological burning effects and generating a protocol or practice guide. We compared the PB seasonality of low-intensity (spring, summer, and autumn) and unburned areas in a total of 12 plots in Pinus nigra Arnold ssp. salzmannii Mediterranean forest. Our vegetation analysis was short term (one year after each PB). We analyzed vegetation coverage, α-diversity (Pielou, Simpson, and Shannon’s index), life forms, and fire-adapted traits using the Canfield transect method, followed by statistical analyses such as non-metric multidimensional scaling (NMDS) and two-way ANOVA. α-diversity was significantly decreased (>55% of dissimilarity) in the burned plots during each season, with the lowest values after summer PB (69% of dissimilarity) when comparing the burned and unburned plots. There was a significant increase in hemicryptophytes (15−20%) and geophyte coverage (from 6% to 14%, or from 4% to 8% in certain cases) in the burned plots after PB seasonality; however, the phanerophytes were reduced (from 13% to 5%). Resprouters were more dominant after PB (an increase of 15–20%), which indicates that resprouters have a faster recovery and generate a fuel load quickly for highly flammable species such as Bromus after low-intensity burning. This suggests that low-intensity prescribed burning may not be the best methodology for these resprouting species. This study helps to understand how burning in the early season can affect inflammable vegetation and the change in fuel that is available in semi-arid landscapes. This is key to achieving the basis for the development of a standardized system that allows for the efficient management of forest services in order to reduce wildfire risks. One objective of this line of research is to observe the effects of recurrent burning in different seasons on vegetation, as well as plant−soil interaction using the microbial and enzyme soil activity.

Change of Cr, Co, and V concentrations in forest trees by species, organ, and soil depth

Heavy metal pollution is one of the most important environmental problems threatening living organisms and environmental health. Thus, there is much research interest in monitoring and reducing heavy metal pollution. Plants’ potential to accumulate heavy metals in various organs differs greatly. Therefore, it is necessary to determine the most suitable species and organs first and acquire knowledge of the subjects such as the transfer of heavy metals within plants and their particular intake into plants. This study investigated Cr, Co, and V, which are among the most important and dangerous heavy metals, and are listed in the primary pollutant list of the Agency for Toxic Substances and Disease Registry. Their concentrations were studied at different depths of soils where Pinus nigra, Pinus sylvestris, Fagus orientalis, and Abies nordmanniana subsp. bornmüelleriana species are grown, in the leaves, cones, wood, bark, and roots. The results showed that the intake of these elements into plant bodies generally occurs through the soil. Additionally, the highest concentrations in both leaves and roots were generally obtained in Fagus orientalis and Abies nordmanniana subsp. bornmüelleriana species. It can be stated that those species are the most suitable species to monitor and reduce heavy metal pollution.