Productivity Of Forest Plantations Research Articles

Maximizing Climate Solutions: Assessing Forest Plantation Productivity and Carbon Sequestration Potential of Tree Species

Climate change is projected to negatively impact forest ecosystems and related industries, emphasizing the urgency of effective mitigation strategies. Forests play a crucial role in climate change mitigation by sequestering carbon dioxide (CO2). Planting trees can contribute significantly, absorbing tonnes of CO2 annually and limiting climate change impacts. This process underscores the vital contribution of forests to mitigating climate change. The aim is to evaluate the role of forest plantation productivity in mitigating climate change and assess the carbon dioxide sequestration potential of some tree species. The carbon dioxide (CO2) sequestration potential of the tree plantations was highest in the moist semi-deciduous north-west (MSDNW) zone followed in a decreasing order by the dry semi-deciduous (DSD) and forest-savannah transition (FST) zones with the values being 23.02 ± 21.84 (SD), 11.16 ± 6.00 and 9.25 ± 5.25 Mg CO2eq ha-1 year-1, respectively. For the various tree species plantations, the CO2 sequestration potential exhibited by Cedrela odorata, mixed species and Tectona grandis stands was given as 36.93 ± 31.21 (SD), 19.06 ± 11.99 and 8.98 ± 4.67 Mg CO2eq ha-1 year-1, respectively. The comprehensive findings underscore the need for nuanced strategies in climate change policies and afforestation initiatives. Sustainable forest management, tailored afforestation practices are recommended to optimize forest plantation contributions to global climate goals.

Effect of climate change on the land rent of radiata pine plantations in Chile: Site productivity and forest fires

Climate change can severely affect forest plantation productivity and fire regimes in temperate regions. The economic evaluation of these impacts is challenging because of the spatially differentiated effects expected to occur across planted areas. We calculated the combined effect of projected climate change on the stochastic land expectation value (SLEV) for a random sample of stands covering the Pinus radiata plantations in central-southern Chile. To simplify the stochastic evaluation problem with changing productivity and fire frequencies over time, we divided rotations into stages, before and after commercial thinning, and assumed that reforestation is at the end of each stage. The SLEV was calculated through Monte Carlo simulations using the coefficients from previously estimated productivity and fire risk statistical models. The predicted combined effect on the SLEV is negative in most regions except those in the southern limit of the specie distribution. In the economically crucial coastal area of the central regions, the negative effect of more frequent fires outweighs faster growth. In the northern drier areas, the SLEV becomes negative due to a large drop in site productivity. Anticipatory reassignments of management regimes have a large adaptation value in these low-productivity sites. Our optimization-simulation results suggest that relative to prescribed management regimes, the optimal rotation age in most low-productivity sites is longer and in most high-productivity sites shorter. Shortening the rotation age by one to two years has an important adaptation value in highly productive coastal sites.

Decision-Tree Application to Predict and Spatialize the Wood Productivity Probabilities of Eucalyptus Plantations

Brazil is one of the world’s wood short-fiber producers, cultivating 7.5 million hectares of eucalypt trees. Foresters and resource managers often face difficulties in surveying reliable Eucalyptus productivity levels for the purpose of purchasing and prospecting lands. Spatial data science (DS) and machine learning (ML) provide powerful approaches to make the best use of the large datasets available today. Agriculture has made great use of these approaches, and in this paper, we explore how forestry can benefit as well. We hypothesized that both DS and ML techniques can be used to improve Eucalyptus productivity zoning based on multiple operational datasets of tree growth and environment. Based on more than 12,000 permanent forest inventory plots of commercial Eucalyptus plantations and the climate, soil, and altitude variables associated with them, a supervised ML approach was adjusted to model the forest plantation productivity. A multi-tuning of the decision-tree (DT) algorithm hyperparameters was prepared to yield 450 DT models, with a better one delivering an RMSE of 53.5 m3 ha−1, split in 35 terminal nodes, here interpreted as Eucalyptus productivity zones. The DT model showed an optimum performance index of 0.83, a coefficient of determination of 0.91, a root mean squared error of 12.3 m3 ha−1, and a mean absolute percentage error only of 3.1% in predicting the testing dataset throughout the study area. The DT rule set was interpreted in a user-friendly table and was prepared to classify any location within the study area in each one of the 35 productivity zones based on the required environment variables of the DT algorithm. The high quality of the model obtained made it possible to spatialize the DT rules, providing a reliable cartographic visualization of the probability levels of true Eucalyptus productivity for a huge region of forest-based industries in Brazil. These data-science techniques also provided a yield gap analysis using a very down-to-earth approach. We estimated a yield gap by an amount of 4.2 × 107 m3, representing a few more than 113,000 ha, or 15% of the current forest base. This is the amount of avoided area expansion to accumulate the same wood stock in case the productivity is raised to the attainable level in each zone. This present study provided deeper analysis and reproducible tools to manage forest assets sustainably.

Effects of climate change on forest plantation productivity in Chile.

Forest plantations in Chile occupy more than 2.2millionha and are responsible for 2.1% of the GDP of the country's economy. The ability to accurately predictions of plantations productivity under current and future climate has an impact can enhance on forest management and industrial wood production. The use of process-based models to predict forest growth has been instrumental in improving the understanding and quantifying the effects of climate variability, climate change, and the impact of atmospheric CO2 concentration and management practices on forest growth. This study uses the 3-PG model to predict future forest productivity Eucalyptus globulus and Pinus radiata. The study integrates climate data from global circulation models used in CMIP5 for scenarios RCP26 and RCP85, digital soil maps for physical and chemical variables. Temporal and spatial tree growth inventories were used to compare with the 3-PG predictions. The results indicated that forest productivity is predicted to potentially increase stand volume (SV) over the next 50 years by 26% and 24% for the RCP26 scenario and between 73% and 62% for the RCP85 scenario for E. globulus and P. radiata, respectively. The predicted increases can be explained by a combination of higher level of atmospheric CO2 , air temperatures closer to optimum than current, and increases in tree water use efficiency. If the effect of CO2 is not considered, the predicted differences of SV for 2070 are 16% and 14% for the RCP26 scenario and 22% and 14% for RCP85 for the two species. While shifts in climate and increasing CO2 are likely to benefit promote higher productivity, other factors such as lack insufficient availability of soil nutrients, events such as increasing frequency and duration of droughts, longer periods of extreme temperatures, competing vegetation, and occurrence of new pests and diseases may compromise these potential gains.

Перспективи вирощування біоенергетичних культур на осушуваних торфових ґрунтах Західного Полісся в умовах кліматичних змін

Goal. To identify the most promising types of bioenergy crops, and explore the potential of their productivity on drained peat soils of Western Polissia in climate change. Methods. Field — to monitor the growth and development of plants, the formation of their yields, laboratory — to determine the quantitative and qualitative characteristics of agrochemical and physicochemical properties of peat soils, measuring and weighing — to determine yields, soil water regime, gamma-spectrometric – to determine the content of radionuclides in soil and crop products, calculation and comparison — to determine the energy efficiency of growing bioenergy crops on drained peat soils of Western Polissia. Results. The productivity potential of the most common species of woody, annual and perennial herbaceous bioenergy crops in the conditions of drained peat soils of Western Polissia was determined. The possibility of obtaining the own seed and planting material of the main types of bioenergy crops in the area of Western Polissia was studied. Conclusions. It is proved that the most promising and technological wood bioenergy crop for growing on drained lands of Polissia is a violet willow of Swedish selection, which under optimal conditions can provide up to 28–30 t/ha of wood biomass annually, which is 10–14 times higher than traditional productivity of forest plantations. Among herbaceous perennial bioenergy crops, the most promising ones are miscanthus and sedge, which provide up to 25 t/ha of dry biomass, and among herbaceous annual crops — sugar sorghum, broom sorghum, and corn, which provide up to 20 t/ha of dry tables. It is proved that on the drained peat soils of Western Polissia, with proper agricultural techniques, it is possible to successfully engage in seed production of most of the studied bioenergy crops, including heat-loving ones such as corn, sugar sorghum, broom sorghum, Sudan sorghum, paise. Due to the high rate of seed propagation, these crops can be quickly introduced into production in a certain area.

Cluster-cooperative project-the basis of rational use of forest food resources in the Amur region

The Amur region has a significant potential for non-wood plant resources: food, medicine, feed, and technology. The northern regions have a territorial advantage in the potential of forest production, where there is a low and average level of agricultural production against the background of a fairly high level of unemployment among the working-age population. Taking into account the cluster policy of the region in the implementation of the designed portfolio of pilot cluster projects, a cluster-cooperative project for the development of an agricultural consumer cooperative for the production, processing and marketing of berries, aimed at the production and production of a wide range of products using wild plants, the formation of a competitive level of price and quality that meets the demand and requirements of customers of export (international) markets, was developed. Through cooperation and integration of personal subsidiary farms within the framework of the project, it is planned to create a single logistics center of the cluster for managing commodity flows of products, ensuring product quality, and organizing certification of products for export. The project is fully integrated into the structure of the organizational and functional mechanism of the agro-industrial cluster of the Amur region, providing support for the project at all stages from the initial stage of project formation to the release of products for export. It is assumed that the implementation of the developed cluster-cooperative project will form the basis for the rational use of non-wood forest resources in the region and will serve not only as a source of income for the local population, the consolidation of permanent personnel in forestry, the development of small and medium-sized businesses, and will also contribute to increasing the productivity of forest plantations.

Space Planting, Competition, and Productivity of a Seven-Year-Old Clonal Teak Plantation in the East Java Monsoon Forest Area

Tree breeding of teak results in selected clones with high growth. Intensive silviculture is required to support a large-scale clonal teak plantation. Appropriate spacing is one of the methods to increase forest plantation productivity. Research of teak clone spacing was conducted on a seven-year-old clonal teak plantation with randomized completely block design. The treatments tested in this study were four plant spacing distances, namely, 3 m × 3 m, 6 m × 2 m, 8 m × 2 m, and 10 m × 2 m. Results show that spacing had significantly different effects on diameter, height, bole height, branch angle, crown area, crown projections, volume, and competition index. However, the height growth did not exhibit any significant differences. The 10 m × 2 m spacing produced the best diameter growth, crown area, and competition index, but has a low volume per hectare and the lowest height of free branch and branch angle. Meanwhile, the 3 m × 3 m spacing will increase bole height and stand volume per hectare. This result suggests that spacing could improve the growth of teak clone but must be followed by intensification of proper maintenance to reduce branch angle and increase bole height.

FEATURES OF THE CONTENT OF CHEMICAL ELEMENTS IN THE CONIFEROUS LARCH GMELINA IN THE AR-EA OF THE UDOKAN COPPER DEPOSIT

The article presents materials for the study of the content of chemical elements in the coniferous larch Gmelina (Larix gmelinii (Rupr.) Rupr.) family Pinaceae (syn.: Larix dahurica Turcz. ex Trautv., Larix amurensis Beissn.), growing in the high-altitude region of the North of the TRANS-Baikal territory, near the Udokan copper Deposit. The purpose of the research is to assess the concentration of a number of chemical elements in high-altitude and permafrost soils, while preparing the territory of the copper Deposit for exploitation. Selection of larch plant samples was carried out in the types of larch forests widely distributed in the research area, in June 2011. The analysis of pine needles samples was performed according to approved methods using modern instruments and equipment in the laboratory of Institute of Natural Resources, Ecology and Cryology SB RAS. It was found that in General L. Gmelin needles have a low concentration of chemical elements, which are arranged in the following sequence: Mg> Sr> Al> Ba> Fe > Ti> Ni> Cu> Mn> Hg> Zn> V> Ag> Cr> Pb> Cd> Sb> Co> Se> As. At the same time, mercury is the only element whose concentration in larch conifers is much higher, 3.8 times, than that of land plants. The article presents a correlation table of the interaction of chemical elements. The table shows that titanium, aluminum, zinc, and silver have a greater effect on the content of chemical elements in conifers. The results presented in the article were obtained in the studied area for the first time. It is important to use the results of this work to monitor environmental pollution, to take into account when using larch to obtain medicinal substances, and to increase the productivity of forest plantations. Further research in this area may be related to other areas of distribution of larch forests, geochemical assessment of the region.

Комплексная оценка качества древесины сосны в лесных культурах разных условий местопроизрастания

Комплексная оценка качества древесины сосны в лесных культурах разных условий местопроизрастания

Resilience of natural forests can jeopardize or enhance plantation productivity

The demand for wood products continues to increase globally. Productivity of forest plantations can be greater than that of naturally regenerated forests. Plantation forestry could thus be employed to meet up to 75% of global wood supply by 2050. The resilience of natural forests could jeopardize plantation productivity. If the plantation scenario is not oriented in the same direction as the natural successional trajectories that are driven by resilience, then naturally regenerating tree species could recover to the detriment of planted species. Unproductive plantations will likely generate sustainability issues, as they must provide ecosystem services (e.g., wood fiber production) while being economically viable for forest management to be sustainable. Our general objective of our study was to assess whether resilience of natural forests can jeopardized plantation productivity. We studied successional trajectories in recent, young and old black spruce plantations that are located within the balsam fir ecological region on balsam fir ecological site types. To compare with a plantation scenario that was more susceptible to aiming in the same direction as resilience-driven successional trajectories, we also studied successional trajectories in recent, young and old black spruce plantations that are not only located within the balsam fir ecological region, but on black spruce ecological site types. Successional trajectories on balsam fir ecological site types pointed towards recovery of balsam fir and white birch, to the detriment of black spruce. Successional trajectories on black spruce ecological site types pointed towards the recovery of black spruce. Thus, we showed that resilience of natural forests could jeopardize plantation productivity when the plantation scenario is not oriented in the same direction as resilience-driven successional trajectories. It also can enhance plantation productivity when the regime is oriented in the same direction as resilience-driven successional trajectories. To ensure that plantations are economically viable and promote sustainability, forest managers should thus favor plantation scenarios that point in the same direction as resilience-driven successional trajectories. Finally, we suggest adopting such scenarios, and stress that it would also be necessary to develop regimes that would promote sustainability in the context of alternative successional trajectories that will undoubtedly arise because of global changes.

Forest plantation productivity – soil interactions within Western Forest-Steppe of Ukraine: effects of pH and cations

Abstract Dark grey podzolized soils on the loess like loams, which are represented in the soil cover within fresh and humidity gradients in the Western Forest Steppe of Ukraine, are characterized by high forest vegetation potential, which ensure the formation of mostly pure and mixed larch and spruce stands with high level of the productivity. Despite the fact that both species are coniferous, their effect on the soil, in particular, on its acid-base indicators (actual and potential forms of acidity, sum of absorbed bases, degree of saturation of bases, content of mobile aluminium), which are important components of soil fertility, are specific. Due to the fact that there is a close interaction between forest plantations and soil properties, changing the participation of species in the stand, it is possible to adjust the actual soil fertility. The soils under both pure and mixed spruce and larch stands are characterized by a high level of potential acidity that reaches the high acidic values in the upper horizons. A similar reaction of soil solution under coniferous forests is caused by acid hydrolysis of aluminosilicates and accumulation of mobile Al in the rhizosphere zone. Simultaneously, the same acidic characteristics, including the presence of movable aluminium, are also found in soils under broadleaved plantations. In general, acid-exchange properties of soils (high potential acidity, unsaturation of bases and availability of movable aluminium) traditionally are considered as unfavourable for vegetation. However, our researches refute it and prove that within certain values, these indicators do not limit the productivity of pure and mixed spruce and larch stands.

Responses of root morphology and seedling growth in three tree species to heterogeneous supplies of ammonium and nitrate

Distribution of absorbable N forms (NH4+ and NO3−) in soil is subject to high spatial heterogeneity, and NH4+ and NO3− deficiency is one of the major factors limiting the productivity of forest plantations. Tree species may have developed different N preferences during their evolution. Here, we investigated the N uptake preference and root growth characteristics in three major tree species (Cunninghamia lanceolata, Pinus massoniana, and Schima superba) in southern China under homogeneous and heterogeneous environments of N forms. Seven N-supply proportions were created with two N forms to establish four levels of heterogeneity, with the NH4+ to NO3− ratio being either 10:0 or 0:10 as high hetero-N, either 8:2 or 2:8 as medium hetero-N, either 6:4 or 4:6 as low hetero-N, and 5:5 as homo-N, respectively. Each seedling was cultured in a specially designed container with two tray halves supplied with equal amounts of total nitrogen but reversed ratios of ammonium and nitrate. Root morphology, root and seedling growth, root-to-shoot ratio, N accumulation and N use efficiency of seedlings were quantified. For all the three species, the root traits were either symmetrical or asymmetrical between the paired patches with the homogenous and heterogeneous supplies of NH4+ and NO3−, respectively. Roots of C. lanceolata in the patch of higher NO3− tend to grow thinner and longer than their counterparts with higher NH4+ supply, whereas roots for P. massoniana and S. superba tend to grow thinner and longer in the higher NH4+ supply patch. The belowground growth increased with the increase in heterogeneity level, but the aboveground growth decreased. The N heterogeneity magnitude was negatively correlated with specific root length and total N accumulation, and positively correlated with root-to-shoot ratio and N use efficiency. The change of root growth pattern might be a strategy to adapt to heterogeneous environments of N forms in soil, and the increase in root-to-shoot ratio would optimize nutrient partitioning and improve N-nutrient absorption in hetero-N soils. Among the three tree species, S. superba had higher responsiveness to the level of N heterogeneity than C. lanceolata and P. massoniana. Our results suggested that C. lanceolata prefers NO3− over NH4+, whereas P. massoniana and S. superba prefer NH4+over NO3−. The findings confirmed a species-specific preference for different N forms and could provide a reference for the nitrogen management of different species in silviculture practice.

Biochar addition to forest plantation soil enhances phosphorus availability and soil bacterial community diversity

Depletion of soil nutrients is a major cause of decline in productivity of forest plantations in successive rotations. Biochar amendment in agricultural systems has been shown to yield various beneficial effects, including increasing soil phosphorus (P) availability. However, the direct and indirect effects of biochar addition on forest soil P dynamics have largely been unexplored. The objective of this study was to examine how biochar produced from harvest residue (leaves and woodchips) affect the P dynamics in second rotation Cunninghamia lanceolata (Chinese fir) plantation soil. An incubation experiment which involved mixing of forest soil with 1% or 3% w/w leaf or woodchip biochar, pyrolyzed at 300 °C or 600 °C, was conducted for 80 days at 20 °C. After 7, 40 and 80 days of incubation, soil samples were analyzed for total and available P, inorganic and organic P pools, and soil phosphatase activity. At the end of the incubation period, bacterial community composition and diversity were analyzed by 16S rDNA sequencing. The leaf biochar produced at both pyrolysis temperatures was more alkaline and had significantly higher soluble P, nitrogen and calcium contents than the woodchip biochar. Soil total and available P increased significantly in all leaf biochar treatments after 80 days incubation compared to the untreated control soil, but the woodchip biochar treatments had no significant effects. At the end of the experiment, Al-P content was significantly lower and Ca10-P content higher in soil amended with both biochar types compared to the control soil, and Fe-P content was significantly higher in the leaf biochar treatments. Contrary to expectations, acid and alkaline phosphatase enzyme activities were significantly lower in some of the biochar treatments after 80 days incubation compared to the control soil. Nevertheless, the diversity of the bacterial community was higher in leaf biochar-amended forest soil than the woodchip biochar-amended and untreated soil at the end of the experiment. In particular, the abundance increased in the leaf biochar soil treatments of P-solubilizing bacteria, such as Burkholderia-Paraburkholderia, Planctomyces, Sphingomonas and Singulisphaera, which can indirectly improve P availability in soil. Thus, conversion of tree harvest residues, particularly leaves, into biochar and recycling back into the soil could be a viable option to boost P availability and help to conserve nutrients or reduce nutrient losses for the next rotation. Before recommending plantation management with biochar, long-term studies are required assessing the life cycle of biochar under field conditions and its promoting effect on growth of C. lanceolata.

RESULTS OF THE 70-YEAR RESEARCH AT THE INTERFACE OF FORESTRY AND SOIL SCIENCE

The main results of studying the effect of artificial woody vegetation on chernozem are briefly described in the article, as well as the influence of soil and soil condition on composition and productivity of forest plantations. The effect of soil salinity on plant growth is characterized. The toxicity of different groups of readily soluble salts, especially chlorides and soda, has been evaluated. The decisive role of the depth of toxic amounts of chlorides and the level of water availability in the soil usability has been established. The ecological series of water availability for plants in different soil types have been developed and the degree of suitability of groundwater of different salinity has been evaluated. The power of the root zone as a limiting factor has been estimated, as far as the level of mineral elements supply for plant nutrition (trophicity) in the soil is determined by the greatest total amounts of phosphorus and potassium in the root zone (excluding potassium enclosed in feldspar lattices). All the intrazonal diversity of nature is due to the nutrient status and moisture content in the soil. Along with the warmth level these limiting resources develop one or another level of soil fertility. The role of subsurface runoff in the formation of forest-steppe landscapes is characterized. The stages and phases of the primary soil-forming process are highlighted. It is argued that soil zonality results from bioinert nature of the soil. The article substantiates the statement that soil fertility is a factor ensuring the stability of life on Earth; and the ways of promoting Soil Science at the level of the theoretical basis for agriculture have been proposed.

Forestry-Taksatic Structure of Forests at SE "Kremenetsk LH"

The study of the forestry-taxation structure of plantations plays an important role during the conduct of economic activities in the territory of forest enterprises of Ukraine. So, timely taken forestry measures will allow to increase the productivity of forest plantations in the territory of forestry enterprises in the future. The database of the Ukrderzhlisproekt JSC as of 01.01.2012 was used for the analysis of the forestry-taxation structure of forests at the State Enterprise "Kremenets Forestry". The typological diversity of forests was characterized according to the developed classification of Alekseiev-Pogrebniak. The total area of the forestry land of the state enterprise “Kremenets Forestry” for the period from 01.01.2009 to 01.01.2012 has not changed and makes up 28,9 hectares, only the area of forest crops increased by 369 hectares and areas covered with forest vegetation increased by 184 ha, the total reserve increased by 246cubic meters and a natural renewal increased by 27 hectares. The structure of areas covered with forest operational forests are prevailing, the share of which is 51 %, forests of nature protection, scientific, historical and cultural purposes – 28 %, recreational-and-health-improving forests – 19 %, and protective ones – 2 % only. The typological diversity of forests in the territory of the experimental site is characterized by a significant number of forest types. The largest area is under the fresh hornbeam forest – 12374 hectares (of which 7378 hectares (60 %) under common oak and other species), and the least area is under the raw black-alder sudubrava – 333 hectares, while other types of forests occupy 408 hectares. The largest total reserve is the pine forest, which is 2785 thousand m3, the second by the number - common oak – 2319 thousand m3, the smallest reserve is forest beech (0,5 thousand m3) and other wood species (0,3 thousand m3). The average change in the reserve at the state enterprise "Kremenets Forestry"; pine forest and common oak have the largest change (49 and 37 thousand m3), and the smallest change in the reserve is in forest beech and other wood species and makes up only 0,26 thousand m3. The average age of wood species: common oak – 67 years (the largest one), common hornbeam – 66 years, pine and silver birch – 57 years, norway spruce has the smallest average age – 33 years. By improvement cutting, the formation of plantations of good natural composition and improvement of the sanitary condition of forests is carried out in an area of about 1,4 hectares in average over the last revision period

Contrasting effects of N addition on the N and P status of understory vegetation in plantations of sapling and matureLarix principis-rupprechtii

Aims The productivity of forest plantations in temperate areas is often limited by nitrogen (N), but may shift towards phosphorus (P) limitation with increasing atmospheric N deposition. Nutrient resorption is a nutrient conservation strategy in plants. Although data on nutrient resorption are available for overstory trees, there are few data for understory vegetation. Methods We examined leaf N and P concentrations and N and P resorption efficiencies (NRE and PRE, respectively) in eight understory species in 11- and 45-year-old Larix principis-rupprechtii stands subjected to N supplementation over a 3-year period.Important findings Leaf N concentrations and N:P ratios increased and P concentrations decreased, with N input in species within the 45-year-old stand, but not in the 11-year-old stand. NRE and PRE were not altered by N input in any of the species in either stand, but N resorption proficiency decreased and P resorption proficiency increased, in the species in the 45-year-old stand. Thus, the growth of understory species may be more P-limited in the 45- versus 11-year-old stand, and nutrient resorption proficiency was more sensitive to N addition than nutrient resorption efficiency. These results will improve the understanding of nutrient use strategies and their responses to N addition in understory vegetation. The contrasting effects of N addition on nutrient status between stand ages cannot be ignored when modeling ecosystem nutrient cycling under global N deposition conditions.

ВЗАЄМОЗВ'ЯЗОК І ВЗАЄМОЗУМОВЛЕНІСТЬ ПРОЯВУ СТИХІЙНИХ ЯВИЩ У ГІРСЬКО-ЛІСОВИХ ЕКОСИСТЕМАХ

Розглянуто взаємозв'язки та взаємовпливи між стихійними явищами у гірсько-лісових екосистемах Карпат – паводками, ерозією ґрунту, селями, зсувами, вітровалами, сніголамами, сходженням снігових лавин, періодичними засухами, лісовими пожежами та іншими. Наведено перелік стихійних явищ, які, взаємодіючи між собою, підсилюють окремі з них, уповільнюючи цим самим інші. З'ясовано, що внаслідок антропогенних змін лісових формацій інтенсифікувалися шкідливі процеси, знизилася продуктивність і стійкість лісових насаджень. Проаналізовано причини виникнення окремих видів стихійних явищ, їх вплив на лісові насадження в нинішній час і в перспективний період. Відзначено значну шкідливість для лісового господарства перманентних вітровалів. Наголошено на збитковості для лісових екосистем катастрофічних сніголамів і сніговалів, які деформують деревину, знижують її приріст за висотою і запасом, та є осередками виникнення грибкових захворювань. Зазначено, що у місцях стихійних явищ зростає небезпека лісових пожеж, знижується естетична і рекреаційна цінність лісових ландшафтів. Наведено перелік заходів, що послаблюють дію негативних природних стихійних явищ та підвищують стійкість лісових екосистем до антропогенного фактору. Важливим є твердження, що вітростійкість насаджень залежить від їх породного складу. Найбільш вітростійкими є насадження за участі ялиці білої та листяних порід.

Effect of pulp and paper mill sludge on the development of 17-year-old loblolly pine (Pinus taeda L.) trees in Southern Brazil

Pinus taeda is a principal conifer tree species and has long been used in forest plantations in Southern Brazil. At the same time, experiments have been carried out in order to determine the wood productivity concerning the economic, social and sustainable forest management practices. In that sense, the organic fertilizers, such as the biosolid residues from pulp and paper industries, are one of the alternatives to achieve this sustainability. Nevertheless, few studies addressing this objective have been reported in Brazil. This study aimed to analyze the growth responses of loblolly pine trees treated with different doses of composted pulp-mill sludge and to propose a management guide based on a wood production simulation. A randomized block design with four replicates for every six treatments - control, 20, 40, 60, 80 and 100 t ha−1 of composted pulp-mill sludge - were carried out in an experimental plantation located in Arapoti, Paraná state, Brazil. Ten 17 year-old-trees for each treatment were selected, the stem variables were analyzed and the stand wood productivity for the optimal dosage was simulated. The trees were significantly influenced by the application of the composted pulp-mill sludge, increasing up to 24, 37 and 127% in stem diameter, height and volume, respectively, and the rotation of the pine plantation control and treated stands was 33 and 21 years, respectively. The forest management applied for a 21-year harvesting cycle (thinning at 7 and 13 years) with 84 t ha−1 of composted pulp-mill sludge resulted in a wood productivity of 11.9 m3 ha−1 or 5.04 Mg ha−1 per year. The results confirm the potential application of pulp-mill sludge as a fertilizer to improve the wood productivity of forest plantations established in poor-nutrient sites. Also, the forest management plans, using the guide proposed, could be replicated in loblolly pine and other tree species plantations according to the end use of wood.

Fate of Acacia mangium in eucalypt mixed-species plantations during drought conditions in the Congolese coastal plains

A mixed-species plantation of Acacia mangium (acacia) and Eucalyptus urophilla x grandis (eucalypt) hybrid was established on the Arenosols of the coastal Congolese plains to improve soil fertility and sustain forest plantation productivity. At one year into the second rotation, some of the acacia started to exhibit yellowing and drying of leaves, resulting in the death of the whole tree. One-third of the pure acacias (100A) and the mixed, 50 % acacia and 50 % eucalypt (50A50E) hybrid, exhibited these characteristics five months later. To limit the damage, the acacias were pruned up to 1.30 meters. The acacias were threatened by a dry season that extended two months longer than during the previous year, probably triggered by sandy textured soils and poor soil fertility (nitrogen < 0.07 % in the 0.05 meters). Soil moisture to a depth of 0.15 meters was higher under eucalypt compared to acacia. It appears that the acacia root structure may have been less tolerant to drought conditions compared with the eucalypts, leading to damage of acacias, which was exacerbated by the acacia’s young age, poor soil fertility and sandy soil texture. One year after pruning, acacias in both 100A and 50A50E presented a healthier tree structure. Furthermore, no negative impact on aboveground biomass -i.e., wood, bark, leaves and branch- has been recorded at 12 and 24 months.

Технологія створення та особливості росту сосни і модрини у лісових культурах Західного Полісся

Встановлено основні технологічні елементи створення модриново-соснових культур, здійснено порівняння особливостей росту у висоту сосни звичайної та різних видів модрини в молодих насадженнях штучного походження свіжих та вологих суборів і сугрудів. Досліджено лісові культури, які ростуть на території Державного лісового фонду державних підприємств «Сарненське ЛГ», «Рівненське ЛГ» та «Соснівське ЛГ» Рівненського обласного управління лісового і мисливського господарства.&#x0D; З’ясовано, що в 1-2-річних лісових культурах значну перевагу за висотою, порівняно із сосною звичайною, має модрина європейська (1,5-2,1 раза), а особливо – модрина широколуската (3,1 раза). У 3-річних культурах перевага модрини європейської над сосною звичайною за середньою висотою становить 1,5, за максимальним показником – 1,7 раза.&#x0D; У 4-річних культурах перевага модрини над сосною за висотою у вологих суборах становить 2,0, а над сосною та ялиною у вологих сугрудах – 2,3-2,4 раза. У 5-річних лісових культурах за показником середньої висоти модрина має перевагу над сосною в 1,5-2,2, над ялиною – в 2,6-3,6 раза.&#x0D; Під час створення лісових культур використано переважно схему розміщення садивних місць – 2,0 х 1,0 м з розрахунку на можливий відпад модрини. Однак він виявився незначним (4-7%), тому крок садіння для породи, враховуючи її високу інтенсивність росту, є недостатнім.&#x0D; З урахуванням підтипів лісорослинних умов, в умовах С2-С3, крок садіння модрини доцільно запровадити в межах 1,5-2,0 м, а в умовах В2-В3 – 1,3-1,5 м.