Trial Plantations Research Articles

Agronomic Suitability for Oil Palm Growing in Uganda

The ever-increasing demand for vegetable oils with its products in Uganda, calls for new areas to be put under oil palm cultivation. A study was conducted to investigate the agronomic suitability of oil palm cultivation in six areas located within a 30 km radius off-shore, on the island and more than 30 km radius off-shore on the mainland. The experiment was superimposed on 45 × 45 m plots in oil palm adaptive trial plantations established in 2008 in Bugiri, Mayuge, Buvuma, Mukono, Kibaale and Masaka districts. The experiment was laid out in a randomized complete block design with three replications. Data on number of oil palm bunches, bunch weight and yield was collected while climatic data (rainfall, temperature, relative humidity and radiation) was acquired from meteorological stations near the experimental locations. Rainfall data analyzed and dry season duration suggested that Mayuge, Masaka, Mukono, Buvuma and Kibaale were moderately favorable for oil palm growing, while temperature and radiation data indicated that all study locations were suitable for oil palm growing. Furthermore, based on relative humidity, Buvuma, Mayuge and Bugiri were suitable for oil palm cultivation but Kibaale, Masaka and Mukono were moderately suitable. Oil palm yield varied significantly (P < 0.05) across locations. The yield was much greater in Mukono (17.7 t/ha/yr) followed by Buvuma (13.8 t/ha/yr) and Kibaale (12.9 t/ha/yr) then Mayuge (10.7 t/ha/yr), Bugiri (10.2 t/ha/yr), and Masaka (10.3 t/ha/yr). The significantly high yield of oil palm observed in Mukono was attributed to the high rainfall received in this location. Based on research findings, Mukono, Masaka, Bugiri, Buvuma, Kibaale and areas within the 30 km radius of Lake Victoria are agronomically suitable for oil palm cultivation.

Dar dikim aralıklarında kurulan kavak (Populus x euramericana ve Populus deltoides klonları) ağaçlandırmalarında artım ve büyüme

Bu çalışmada, levha ve kağıt endüstrisinin talebine uygun odun üretimine yönelik, dar dikim aralıklarındaki kavak ağaçlandırmalarının gelişimleri araştırılmıştır. Bu amaçla, P.x euramericana ve P. deltoides klonlarıyla (I-214, I-45/51, SAMSUN (I-77/51), İZMİT (S.307-26) ve 89.M.060) deneme ağaçlandırmaları tesis edilmiştir. Denemelerde 3m x 1,5m (4,5 m2/ağaç), 3m x 2m (6,0 m2), 3m x 3m (9,0 m2), 3m x 4m (12,0 m2) ve 3m x 5m (15,0 m2) olmak üzere, 5 değişik dikim aralığı uygulanmıştır. Tüm kavak klonları için, bonitet tabloları ve çift girişli hacim tabloları düzenlenmiştir. Ayrıca, 3 bonitet sınıfı ve 5 değişik dikim aralığına göre, 3 – 12 yaş kademesi için hasılat tabloları hazırlanmıştır. Dar dikim aralıklarındaki kavak ağaçlandırmalarında çap, boy ve meşcere unsurlarının artım ve büyüme ilişkileri ortaya konulmuştur. Analiz sonuçlarına göre, en uygun klonun 89.M.060 ve dikim aralığının 4,5 m2/ağaç olduğu belirlenmiştir.

Long-term effects of planting density and site quality on timber assortment structure based on a 41-year plantation trial of Chinese fir

Stand density control coupled with site control is a key technique for cultivating large-diameter timber of Chinese fir trees, whose yield can be effectively increased by the optimal density and site management mode employed. This study aimed to evaluate the dynamic changes in timber assortment structure under differing initial planting densities and site quality based on growth data of a 41-year trial of Chinese fir plantations. Our results showed that the total timber yield and both large-diameter timber outturn and the outturn rate all increased with better site quality under the same initial planting density. Further, the outturn peak as well as outturn rate peak for both medium- and small-diameter timber was reached sooner with improved site quality. For the same site class, a lower initial planting density augmented the total timber outturn rate, and also resulted in less time required for the total timber outturn rate to reach a constant or maximum value. Finally, the total timber outturn rate of all density plots tended to be nearly identical. Using a high planting density increased the outturn of small-diameter timber, whose outturn peak was delayed in the denser plots. The bolstering effect of low density upon the growth of large-diameter timber was enhanced by higher site quality, with density-induced differences in large-diameter timber more pronounced; conversely, that promoting effect weakened under poor site quality conditions. The interaction between planting density and site index significantly influenced the growth of any timber assortment of Chinese fir in the early stage following its formation. Notably, the significant effect of site index on large-diameter timber lasted longer than that of other timber assortments. The optimal site conditions for cultivating large-diameter timber trees of Chinese fir consist of a site class ≥ 20 with a planting density limited to no more than 1667 trees/ha, whose stand rotation period must be over 26 years, so as to maximize the output of large-diameter timber yield. Our empirical findings will be helpful for the construction of an optimal cultivation mode for the density, site, and rotation age of large-diameter timber in Chinese fir plantations.

Understory vegetation diversity, soil properties and microbial community response to different thinning intensities in Cryptomeria japonica var. sinensis plantations.

Soil microorganisms are the key factors in elucidating the effects of thinning on tree growth performance, but the effects of vegetation and soil on the species composition and function of soil microorganisms after thinning are still not well elaborated. The effects of thinning on understory vegetation diversity, soil physicochemical properties and soil microbial community composition were investigated in a thinning trial plantation of Cryptomeria japonica var. sinensis, including four thinning intensities (control: 0%, LIT: 20%, MIT: 30% and HIT: 40%), and the relationships of the microbial community structure with the understory vegetation diversity and soil properties were assessed. The results showed that thinning had a greater effect on the diversity of the shrub layer than the herb layer. The soil bulk density and the contents of soil organic matter, total potassium and nitrogen increased with increasing thinning intensities. The Shannon and Chao indices of soil bacteria and fungi were significantly lower in the LIT, MIT and HIT treatments than in the control. Thinning can significantly increase the abundance of Proteobacteria and Actinobacteria, and higher thinning intensities led to a higher relative abundance of Ascomycota and a lower relative abundance of Basidiomycota, Rozellomycota, and Mortierellomycota. Redundancy analysis indicated that soil physicochemical properties rather than understory vegetation diversity were the main drivers of microbial communities, and fungi were more sensitive to soil properties than bacteria. Functional prediction showed that thinning significantly reduced the potential risk of human diseases and plant pathogens, and the nitrogen fixation capacity of bacteria was the highest in the HIT treatment. Thinning significantly increased the relative abundance of cellulolysis and soil saprotrophs in bacteria and fungi. The findings provide important insights into the effects of thinning on C. japonica var. sinensis plantation ecosystems, which is essential for developing thinning strategies to promote their ecological and economic benefits.

Effect of biochar on soil acidity and aluminum morphology in tea plantations

Soil acidification in tea plantations has become a key factor restricting the development of the tea industry. Biochar reduces soil acidity significantly and has good short-term effects of acidic soil improvement in tea plantation trials, but the duration of the effect and the long-term environmental effects of biochar are still unclear. In this study, the acidic tea plantation soil to which biochar was applied five years ago was studied. The biochar applied to the soil was separated and analyzed for surface elements, and the aluminum form of the soil was measured. The results showed that : (1) Five years after biochar was applied to the soil, the surface aluminum elements of biochar increased significantly, indicating that biochar had a certain degree of adsorption effect on aluminum in the soil; (2) the pH of tea plantation soil increased significantly; (3) the exchangeable aluminum [Al3+] and monohydroxy and dihydroxy aluminum [Al(OH)2+, Al(OH)2+] both had the potential to convert to colloidal aluminum [Al(OH)3], and this conversion reduced the content of reactive aluminum in the soil, thus increasing the soil pH and reducing the toxicity of aluminum to plants.

Aeration Quality of Root Trainer and Rooting Media in the Artificial Regeneration Studies of Myristica malabarica Lam.

Tropics are known for the species richness and the evergreen rain forests are blessed with many tree species, which are of economic importance. Myristica malabarica is an important evergreen tree species, which urgently require artificial regeneration technology for plantation trials. Hence this work has great importance. The present study was carried out using seeds from two forest localities (L1 and L2) and sown in four sowing media (SM1-SM4) and control (SM5) in root trainers and reusable poly-pots. Germination trials using fresh and stored seeds with and without seed treatments were also performed. Higher germination percentage of 44% was exhibited by seeds collected from L1 and sown in perlite and soil in root trainer (SM3). Least germination percentage of 12.75 % was found in seeds collected from L2 and sown in garden soil in nursery bed (SM5). Higher germination value (GV) of 0.515 was recorded in seeds collected from L1 and sown in perlite and soil (SM3) and least value of 0.024 in seeds collected from L2 and sown in garden soil (SM3). Seeds soaked in water (T3) and sown in perlite and soil (SM3) and nutmeg pericarp and soil (SM4) showed higher germination percentage of 84.5 % and 83.5 % respectively while seeds without pretreatment (T1) and sown in vermiculite and soil (SM2) exhibited 21.75 % of germination in root trainer. Germination percentage was higher in seeds sown in perlite and soil in root trainer. Seeds sown in vermiculite and soil in pots recorded greater MGT of 40.57 days and least in seeds sown in perlite and soil in root trainer. Germination rate and CVt was higher in all sowing medium in root trainer compared to that in pots. Greater germination value of 3.085 were recorded in seeds sown in perlite and soil in root trainer and least values in seeds sown in vermiculite and soil in pots. Thus the results directly proves the ability of root trainers in environmentally safe artificial generation of seedlings for plantation purpose.

Branch development in monoculture and mixed-species plantations of Betula alnoides, Erythrophleum fordii and Pinus kesiya var. langbianensis in southwestern China

The quantitative and morphological characteristics of branches are key factors influencing both tree growth and wood quality. The effects of stand density and artificial pruning on branch development have been widely studied in monoculture, while branch development in mixed forests has rarely been reported. In this study, branch development of Betula alnoides, Erythrophleum fordii and Pinus kesiya var. langbianensis were evaluated in a 6-year-old mixed-species trial plantation in Yunnan Province, China, which included five treatments: monocultures of B. alnoides, E. fordii and P. kesiya var. langbianensis, and mixtures of B. alnoides with E. fordii or P. kesiya var. langbianensis. Branch quantity (number, proportion, and density), morphology (diameter, length, and angle), and distribution (height and orientation) were measured from 63 dominant or codominant trees randomly sampled in the trial plantation. The results showed that the number of live and total branches of B. alnoides in the mixture was significantly higher than those in its monoculture, and the branch density of B. alnoides in the mixture with P. kesiya var. langbianensis was also higher than those in its monoculture and the mixture with E. fordii. Mixing with B. alnoides had no significant effect on the branch quantity of P. kesiya var. langbianensis, but significantly lowered the branch quantity of E. fordii. The branch angle was not significantly affected by the mixture for these species. More small branches (branch diameter < 15 mm) were observed in the mixed plantations than in the monocultures for the three species, while significantly lower branch diameter and length were seen in the mixture than in the monoculture only for B. alnoides. Significant differences were absent in the branch distribution of B. alnoides and E. fordii among the four cardinal orientations regardless of whether they were in the monoculture or in the mixture. The variations in branch quantity and morphology along the stem were much more determined by species-specific attributes and less affected by the mixture. It was concluded that a mixture of B. alnoides and E. fordii could significantly control the branch size of B. alnoides, reduce both the branch size and branch quantity of E. fordii, and thus be beneficial for high-quality timber production.

Above-ground Carbon Stocks of Tectona grandis and Gmelina arborea Plantations in Njala University, Southern Sierra Leone

The unprecedented increase in atmospheric CO2 concentration has attracted global research attention on the potential role of tree plantations in climate change mitigation. There is an urgent need to estimate the above-ground biomass (AGB) and carbon stock in forest plantations. This is particularly essential for Sierra Leone, where above-ground biomass (AGB) and carbon stock data are presently lacking. This study estimated the above-ground biomass accumulation and carbon stock of Tectona grandis Linn.f. and Gmelina arborea Roxb. in the spacing and plantation trials at Njala University, Southern Sierra Leone. The assessment was based on a total inventory of trees having a diameter at breast height (DBH) ≥ 5 cm and tree height. Above-ground biomass (AGB) was estimated using the allometric equation by Chave et al. (2005), and above-ground carbon (AGC) stock was calculated by multiplying the biomass with a conversion factor of 0.5. The result showed that the mean above-ground carbon stock for Gmelina arborea was higher in the plantation trial (25.2 t ha-1) than in the spacing trial (7.5 t ha-1). For Tectona grandis, the mean above-ground carbon stock was similarly higher in the plantation trial (6.6 t ha-1) than in the spacing trial (1.5 t ha-1). The results further suggest that the variation in the means of above-ground carbon stock is not dependent on the tree species type and experimental site because there were no significant differences (P&gt;0.05) between the tree species and experimental sites.

Adaptive potential and productivity of two Salix viminalis L. clonal varieties grown in North Central Bulgaria

Salix viminalis L. is a broadly cultivated willow species that has been intensively used for breeding purposes, particularly in selection of clones and hybrids for biomass production. The present study aimed to explore and compare growth and adaptability of two basket willow (Salix viminalis L.) clonal varieties - rubra and purpurea - at the specific edaphic and climate conditions and cultivation practice presented in an experimental plantation in North Central Bulgaria. The influence of spacing, genotype, root age and rotation on their productivity were also investigated and allometric relationships for non-destructive estimation of woody plant biomass were suggested. The trial plantation was established in the spring of 2018 as 4 sectors of a Nelder wheel plot with 15 nearly-square spacings, ranging from 0.25 to 9.80 m2 (40000–1020 plants per hectare). The two varieties were arranged in 4 four-spoke sectors (2 sectors per clone). Data collection took place from 2018 to 2020 and comprised 1- and 2-year rotations. The study showed that Salix viminalis var. rubra was more susceptible to desiccation-causing adverse climatic changes, poorly adapted to the specific conditions of the study site and gradually died out during the second and the third year. Salix viminalis var. purpurea exhibited steady survival rate (97 - 77%) and annual biomass productivity varying from 3 to 17 Mg/ha/year across the densities, sectors and years. During the first year of growth purpurea variety had a significantly higher plant weight and sprout number than rubra variety. Growing space affected positively the number of shoots and tree dendromass, and sprouting was reinforced by coppicing that doubled the shoot number during the subsequent rotation. This was reflected in the development of the stump-level allometric models that were differentiated according to rotation. The stump-level allometric model of higher predictive power was based on the main shoot length and shoot number. An exponential relationship to the breast-height shoot diameter was also suggested for biomass estimation of each sprout separately.

Effect of Organic Amendment on the Physicochemical Characteristics of Tailings Dam Soil and Root Development of Tree Species, Fifteen Years After Planting

Among mine wastes, tailings are known to have the largest environmental impact, as they have high concentrations of trace elements and are susceptible to wind dispersal and water erosion. A tree plantation trial was installed at Kipushi tailing (DR Congo) in order to mitigate the contaminant dispersal in the surrounding areas. Fifteen years later, the present study was conducted for the purpose of investigating the macronutrient and metal content in amended holes and assessing the performance of tree species through root behavior in the tailings dams. Results show elevated available P, K, Ca, and Mg concentration in the surface and amended layers, which is higher than the unpolluted soil of the miombo woodland. Trace metals were manifold higher compared to the pedo-geochemical background of the region, with Cu and Co concentration tending to increase in the organic matter-rich layers, while Zn, Cd, Pb, and As remained higher in tailings. Compared to the tailing layer, roots grew well in the amended layers, but few roots ranging from very fine to big from all the surviving species were able to grow beyond the amended layers, indicating the possibility of tree survival on the tailings dams over many years. Acacia polyacantha and Psidium guajava are species that showed a higher quantity of roots in the unamended tailing layers. Leaves should be avoided for human or animal consumption, but as the concentration of Cu, Zn, and Co in guava was lower, there is no indication of hazards in case of their consumption. Therefore, the use of well-adapted tree species on the mix-up of the organic amendments with the uncontaminated topsoil seemed to be a good technique for the reclamation of larger polluted areas.

Tamanu (Calophyllum inophyllum) growth performance on different types of degraded peatlands in Central Kalimantan

To achieve its national goals in climate and landscape resilience, including bioenergy production, the Government of Indonesia has launched an initiative to restore 14 million hectares of degraded land, including 2 million hectares of peatlands, by 2030. Here we present early findings on tamanu adaptability and tree growth (height, diameter and branches) on two types of degraded peatlands in Central Kalimantan. The paper reports peatland type and tamanu tree growth and adaptability in a 3-ha plantation trial plot over three years and a 2-ha plot over two years in Kalampangan and Buntoi villages. Results show survival rates of 82% in the plot on ombrogenous peat in Kalampangan and 81% on topogenous peat in Buntoi. Furthermore, the growth performance of 2-year-old tamanu trees on topogenous peat in Buntoi with an average height of 1.74 m and diameter of 3.97 cm at 5 cm above ground level and 15 branches was better than on ombrogenous peat in Kalampangan with an average height of 0.68 m and diameter of 1.43 cm at 5cm above ground level and five branches. While initial survival and tree growth results are promising, further monitoring of flowering and fruiting is necessary to determine tamanu’s viability for biodiesel production on degraded peatlands.

Growth performance of Calophyllum inophyllum at a bioenergy trial plot in Bukit Soeharto Research and Education Forest, East Kalimantan

The Indonesian government has committed to providing its entire population with energy through the National Energy Policy, which highlights the importance of diversification, environmental sustainability, and enhanced deployment of domestic energy resources. The contribution of new and renewable energy (NRE) to the nation’s energy supply is mandated to reach 23% by 2025, with bioenergy an important NRE alternative. If developed and deployed appropriately, bioenergy plantations have potential to restore degraded land and enhance biodiversity and environmental services while supporting rural livelihoods. As a potential biofuel tree species suited to the tropics, Calophyllum inophyllum (nyamplung) is being tested across wide-ranging degraded forest conditions in Indonesia. Nyamplung is a potential biodiesel alternative as it grows well in harsh environmental conditions, produces non-edible seed oil, has high amounts of kernel oil and fruits profusely. Here we report growth performance in a plantation trial plot established in February 2018, on previously burned land in Mulawarman University’s Bukit Soeharto Research and Educational Forest. Growth of this two-year-old plantation is strong compared to other Indonesian sites, with average survival rate above 90% on Ultisol soil, which is classified as low fertility and acidic. The findings reveal that different doses of fertilizer applications and slope gradient have no significant effects on growth performance. In addition, trees have already started to flower and fruit, and are colonized by bird species and insects, including bees and butterflies. The study indicates that nyamplung adapts well to different land and soil types. Bioenergy plantations on degraded land are a promising approach for land restoration, and enhance native biodiversity and environmental services while providing a source of renewable energy.

ОСОБЕННОСТИ СТРОЕНИЯ ГЕОГРАФИЧЕСКИХ ЛЕСНЫХ КУЛЬТУР СОСНЫ ОБЫКНОВЕННОЙ ПО ДИАМЕТРУ

The article analyzes the indicators characterizing modern structure in terms of diameter in provenance trial plantations of Scots pine, created in 1959 by manually planting 2-year-old seedlings using Kolesov's sword at the Stupinskoye Pole training ground in the Voronezh Region, with an area of 26.1 hectares on agricultural land. Based on the data of continuous tree counts on 32 temporary sample plots established in 2018-2020, and representing 18 forest-steppe and 14 steppe ecotypes from the forestries of the European part of the Russian Federation and Ukraine, the diameters of the thinnest, middle and thickest pine trees were determined, as well as rows of their distribution were built for 2 and 4 cm steps of thickness. It was found that distribution of trees in the forest-steppe ecotypes of pine has a unimodal character, typical for a normal distribution, but with insignificant right-hand asymmetry. The distribution of trees of steppe ecotypes is also asymmetric, but bimodal one. In this case, the top of the first right-sided and smaller peak falls on a step of 20 cm thickness, and the top of the second, higher peak falls on the central step of thickness (28 cm), which is associated with the natural cyclic-wave decay of small-sized pine trees of steppe ecotypes growing in conditions of the forest-steppe, where the object of research is located. In pine plantations of forest-steppe ecotypes, 65.3% of the trees are concentrated in the five central steps of thickness, and in the steppe ecotype - only 52.0% of their total number

УЧЕНЫЕ, ПЕДАГОГИ, ПРАКТИКИ ЛЕСОРАЗВЕДЕНИЕ И ВОССТАНОВЛЕНИЕ ЛЕСОВ

The Voronezh region has a long history in the creation and cultivation of man-made forests in the forest-steppe and steppe zones and in the formation of forest reclamation complexes in forest-agricultural landscapes. Such work, training of personnel for forestry enterprises, the development of theoretical provisions is associated with the well-known names of prominent scientists and their students of the Voronezh Forestry University. Treshchevsky Igor Vladimirovich - Professor, Doctor of Agricultural Sciences, Honored Forester of the RSFSR, participant of the Great Patriotic War. With his participation and under his leadership, work was carried out for the first time on the reclamation of disturbed lands of the KMA. Important studies were carried out and recommendations were developed for optimizing the assortment of species and agricultural technology for growing them on dumps, a method for determining the economic efficiency of creating protective plantations was proposed and tested. Igor Vladimirovich owns more than 130 works, most of which are devoted to forest reclamation of disturbed lands. Professor Treshchevsky I.V. prepared 13 candidates of sciences. V.G. Shatalov and Ya.V. Pankov. Popov Vladimir Ksenofontovich - a famous scientist forester, professor, honored worker of higher education, full member of the Academy of Natural Sciences and the Academy of Quality Problems of the Russian Federation, rector of VSFI, VSAFT (1985-2005). Vladimir Ksenofontovich is the author of over 200 scientific papers. Under his leadership and direct participation, experimental-production facilities for provenance trial plantations of birch, pine-birch crops, and pine cultures of various densities were created. Shatalov Viktor Grigorievich - Doctor of Agricultural Sciences, Professor. He is the founder of the scientific direction - floodplain afforestation, principles of management in water protection zones. Based on the results of many years of research, he published 243 works, including 14 monographs, 1 textbook and 7 teaching aids. V.G. Shatalov paid much attention to personnel training. He prepared 10 candidates and 2 doctors of sciences. Deryuzhkin Rostislav Ivanovich - Doctor of Agriculture, Professor. Rostislav Ivanovich can rightfully be considered the creator of forestry. With his direct participation, tens of hectares of forest plantations of larch, pine and oak were laid. During the period of his work, he prepared 160 graduate students and 22 candidates of sciences, published more than 150 scientific papers. Pankov Yakov Vladimirovich - Doctor of Agricultural Sciences, Professor, a recognized specialist in the field of the environment, rational nature management and forest reclamation. With his participation, over 40 years, unique biological objects were created on the dumps of the KMA. He prepared 4 doctors and 15 candidates of sciences; he published over 250 scientific works, including 14 monographs, received copyright certificates. All these scientists make a huge contribution to the theory and practice of afforestation and reforestation, training for the forestry industry

Изменчивость признаков вегетативных органов лиственницы Гмелина в Забайкальском крае

Изменчивость признаков вегетативных органов лиственницы Гмелина в Забайкальском крае

Short-term effects of wood ash application on soil properties, growth, and foliar nutrition of Picea mariana and Picea glauca seedlings in a plantation trial

Burning biomass for energy generates ash that could be applied as a soil amendment to ameliorate acidity and mitigate nutrient losses associated with biomass harvesting. These soil improvements may also enhance tree growth and foliar nutrition. In this study, we applied low- and high-carbon wood-derived ash at rates of 0 (control), 1000, and 10 000 kg·ha−1 (dry weight equivalents) to soils planted with Picea mariana (Mill.) B.S.P. and Picea glauca (Moench) Voss in a replicated (5) factorial design. We measured soil properties, tree seedling height, and foliar nutrient contents prior to and 4 mo after wood ash addition to determine the immediate effects on soil physical, chemical, and biological properties, and tree seedling performance. We conclude that there were no negative effects of applying either wood ash and that application of ash at 10 000 kg·ha−1, particularly with the low-carbon ash, produced the greatest changes. We anticipate that changes may become more evident over the longer term, especially with respect to tree growth and nutritional responses (e.g., as nutrient uptake demand increases) once the seedlings become more established.

Зміна діелектричних показників сосни звичайної в умовах напіввільного утримання кабана дикого

На прикладі Центрального Полісся України показано особливості використання електрофізіологічних показників (імпедансу (R) і поляризаційної ємності (C)) є перспективним методом індикації стадій впливу напіввільного утримання мисливських тварин на лісові насадження. На території Центрального Полісся функціонує близько 30 вольєрів, у яких утримують кабана дикого (Sus scrofa L.). Досліджено сезонні зміни діелектричних показників сосни звичайної (Pinus sylvestris L.) на території вольєрів ТОВ "УТМР", ГО "ЖОМК "Касадор", ДП "Баранівське ЛМГ", ДП "Лугинське ЛГ", ДП "Коростишівське ЛГ" та ГО "Романівський МРК "Ірбіс-Брачки", площа яких не перевищує 5,0 га. Закладено 12 пробних площ (шість з яких – контрольні) у соснових деревостанах віком 60-91 рік, які зростають за ІБ-ІІ класом бонітету. Пробні площі розташовані у трьох типах лісу (В2-дС, С2-гдС, С3-гдС). Вимірювання діелектричних показників виконували у лютому-березні, червні-липні та жовтні-листопаді упродовж 2018-2020 рр. приладом Ф4320 на частоті 1000 Гц за методикою Г. Т. Криницького. Встановлено, що діелектричні показники мають виражену динаміку та характеризують сезонні зміни інтенсивності процесів життєдіяльності. Поляризаційна ємність на пробних площах коливалася у лютому-березні в межах 5,68±0,17-7,46±0,25 nF, у червні-липні вона зросла до 11,31±0,67-24,55±0,91 nF, а у жовтні-листопаді знизилася до 6,03±0,29-8,97±0,27 nF. Показники імпедансу впродовж сезону спочатку знизилися від 22,43±0,63-36,10±2,48 кОм до 10,20±0,54-21,83±1,35 кОм, а потім зросли до 20,50±0,59-33,35±2,49 кОм. Встановлено достовірну різницю діелектричних показників насаджень Pinus sylvestris для вольєрів ДП "Баранівське ЛМГ" (С – tф = 2,72-3,88 та R – tф = 2,24-3,05; t05 = 2,02) та ДП "Лугинське ЛГ" (С – tф = 2,78-11,69 та R – tф = 2,52-8,93; t05 = 2,02). Коефіцієнт варіації поляризаційної ємності на дослідних пробних площах за періодами спостереження становив відповідно 14,1-19,4 %, 16,6-31,5 % та 8,9-21,7 %, а імпедансу – 12,7-34,7 %, 15,7-35,2 % та 12,8-38,4 %. У червні-липні (період активної вегетації), на фоні загального зростання показників поляризаційної ємності та зниження імпедансу, відчутно зросли коефіцієнти варіації поляризаційної ємності на ПП ((Fфакт = 47,56 &gt;&gt; F0,95 (1; 21) = 4,35)) порівняно з попереднім періодом, водночас для імпедансу таке збільшення коефіцієнта варіації не спостерігається ((Fфакт = 0,24 &lt; F0,95 (1; 21) = 4,35)). Отримані результати досліджень свідчать про неоднозначність впливу напіввільного утримання Sus scrofa на життєдіяльність дерев Pinus sylvestris.

Linking above-ground biomass production to below-ground carbon fluxes across stocking, clone, fertilization, and understory elimination in Pinus radiata D.Don plantations, New Zealand

The linkage between above-ground biomass production and below-ground carbon fluxes as influenced by silviculture has been insufficiently studied. We tested the effects of stocking, clone, fertilization, and follow-up herbicide treatments on below-ground carbon flux (BCF), above-ground biomass production (AGB), the ratio (BCF/AGB), tree diameter (DBH), height (H), basal area (G), and leaf area index (LAI) for a Pinus radiata D. Don plantation trial in the Canterbury region of New Zealand. Mixed-effects analysis of variance was carried out using data at the plot and clone levels.The H, DBH, G, AGB, BCF and the BCF/AGB ratio were influenced significantly by the main effects of stocking (p < .05), and the follow-up herbicide (p < .001). The main effects of clone had significant influence on H (p < .001), BCF (p < .01) and the BCF/AGB ratio (p < .01). Values of AGB and G increased with stand density, while DBH and H decreased with stand density. The significant stocking × follow-up herbicide interactions observed for DBH, G and AGB, suggested that follow-up weed control alleviated understory-induced water and nutrient stresses. Significant clone × follow-up herbicide interactions for DBH and AGB (p < .05), and clone × stocking interactions for G (p < .05), and no interaction of silvicultural treatments for BCF and BCF/AGB ratio were observed. Clones 1 and 3 exhibited greater AGB and smaller BCF/AGB ratio, compared to slower growing clones (i.e., Clones 4 and 5), suggesting certain clones were more productive above-ground at the expense of less carbon partitioned below-ground. These findings highlight that stocking, follow-up herbicide, and clone, in that order, had the greatest influence on above- and below-ground variables, suggesting that those silvicultural practices shifted carbon partitioning above-and below-ground. We conclude that well-performing clone planted with appropriate stand density and with follow-up weed control treatments may increase aboveground radiata pine productivity.

ОСОБЕННОСТИ РОСТА И СОСТОЯНИЕ ЛЕСОСТЕПНЫХ И СТЕПНЫХ ЭКОТИПОВ СОСНЫ ОБЫКНОВЕННОЙ В ГЕОГРАФИЧЕСКИХ КУЛЬТУРАХ ВОРОНЕЖСКОЙ ОБЛАСТИ

The indicators characterizing growth, productivity and living conditions of forest-steppe and steppe ecotypes of Scots pine in provenance trial plantation of Stupinsky Pole training ground in the Voronezh Region, obtained in 2019 on temporary sample plots, have been analyzed. The object of comprehensive research are forest-steppe and steppe ecotypes of Scots pine in 60-year-old provenance trial plantations growing in the Ramonsky district forestry of the Voronezh forestry. The studied cultures were laid on the lands after agricultural use in 1959 under the guidance of Professor M. M. Veresin. The planting material was 2-year-old standard seedlings of Scots pine, planted manually under Kolesov's planting iron. The type of growing conditions is A2 and B2. No additional planting was made. Based on the materials of 13 test plots laid according to the standard method, some features of the growth of forest-steppe and steppe pine ecotypes has been revealed. Their productivity and living condition have been evaluated. The highest average height is a characteristic of the steppe ecotype from the seeds of the Valsky forestry of the Saratov region and the forest-steppe ecotype from the seeds of the Platonov forestry of the Tambov region. The lowest average height is in crops of the forest-steppe ecotype from the seeds of the Monastic forestry of the Penza region. Local ecotypes (seeds from the Khrenovsky forestry) have the largest average diameter. The steppe ecotypes from the Saratov Region have the smallest diameter. The variability of the diameters of the preserved 60-year-old trees at a height of 1.3 m and at the surface of the soil was estimated as average - 16.99-31.09% and 19.50-29.94%, respectively. It is also typical for ordinary forest plantations. All the trees are classified as industrial trees. The stock of raw wood depends on the stand density. The largest stock was recorded in cultures from the Bryansk region (Krasnoslobodskoye forestry) due to the greater number of preserved trees. The smallest is among forest-steppe ecotypes of the Belgorod region. The analysis of the vital state of the surviving plants has showed that the best indicators have forest-steppe ecotypes from adjacent areas with similar climatic conditions. At the same time, the amount of preserved pine trees of all ecotypes per 1 ha is not large. Their preservation is 3.8-10.2% of the trees planted in 1959. Preservation varies greatly in ecotypes. Edaphic conditions for the growth of maternal stands where seeds were harvested have a significant impact on the living conditions of pine provenance trial plantations

First record of off-season flowering in Populus deltoides from India: paradigm of climate change indicator

Populus deltoides is a fast-growing woody species possessing plethora of industrial applications. This species evolutionarily developed unisexual male and female catkin inflorescence on separate trees. Flowering usually occurs during early spring before the development of foliage, where buds appear near axils or at the extending shoots. In 2019, surveys were undertaken to study the flowering pattern of P. deltoides in the states of Punjab, Haryana, Uttar Pradesh and Uttarakhand in northern India. Interestingly, an anomalous flowering behaviour (appearance of off-season male catkins during autumn, i.e. October) was observed in a plantation trial at Kapurthala, Punjab. The male catkins were 2.7-3.1 ± 0.07cm long and 0.3-0.5 ± 0.03cm wide, which is significant for flowering and liberation of pollen grains. Preliminary results suggested that climatic factors, such as episodes of high or low temperature and the precipitation variation forcing the tree species to behave differently. Unearthing the climate-driven off-season flowering in other tree species alluded the stimulation of phytohormones, such as gibberellic and salicylic acid concentrations influencing the flowering time, therefore, needs further investigation in case of P. deltoides. Overall, this work provides early clues of changing climatic scenario altering the flowering pattern of a tropical forestry tree species.