Biomass Volume Research Articles

Unravelling patterns of forest carbon stock along a wide elevational gradient in the Himalaya: Implications for climate change mitigation

In an era of climate change, quantifying forest biomass and carbon stock along elevational gradients in mountainous areas assumes immediate relevance for carbon budgeting and forest management. Here, we carried out extensive field studies to quantify the tree biomass and carbon stock of major forest types along a wide elevational gradient (350–3450 m) in Jammu and Kashmir, a region located in the northwestern Himalaya. We adopted a stratified random cluster sampling approach to generate ground-based data on structural variables (diameter at breast height-DBH, stem height, basal area, stem density, species richness), and quantified biomass and carbon stock volume using allometric equations in 12 major forest types in the region. We found a significant difference in all the tree structural variables among the forest types. Our results show a significantly positive correlation between DBH and height, but a significantly negative correlation of stem density with DBH and height. We observed a higher basal area in the forest types between 1750 and 3350 m elevation, with the highest value (104.4 ± 29.0) found in Fir forest. We also found higher stem density values at mid- and high-elevations in comparison to low-elevation, but the trend was inconsistent. To evaluate the influence of elevation on the structural attributes, we fitted a Linear Regression Model (LM) for each variable, followed by F-test. We observed a significant effect (p < 0.008) of elevation on all the forest tree structural variables, species richness, biomass and carbon stock. All these variables, except species richness, showed a positive relationship with elevation. We found the highest aboveground-, belowground-, total biomass, and carbon stock in the forest types at high elevation above 1750 m. The most significant tree species in terms of biomass and carbon stock contribution was Abies pindrow, followed by Cedrus deodara and Pinus roxburghii, thus making them suitable tree species for forest conservation and restoration in this Himalayan region. Principal component analysis of anthropogenic disturbances revealed the fire mostly associated with the forest types dominated by P. roxburghii, stem cutting with those dominated by C. deodara, P. wallichiana and A. pindrow, and grazing with the high-elevation forest types. Overall, our study unravels the patterns of forest carbon stock along a wide elevational gradient in this Himalayan region, with immediate implications for climate change mitigation policy and practice in mountainous landscapes.

Geographical variation in the trait‐based assembly patterns of multitrophic invertebrate communities

Abstract It has been argued that the mechanisms structuring ecological communities may be more generalizable when based on traits than on species identities. If so, patterns in the assembly of community‐level traits along environmental gradients should be similar in different places in the world. Alternatively, geographical change in the species pool and regional variation in climate might result in site‐specific relationships between community traits and local environments. These competing hypotheses are particularly untested for animal communities. Here we test the geographical constancy of trait‐based assembly patterns using a widespread multi‐trophic community: aquatic macroinvertebrates within bromeliads. We used data on 615 invertebrate taxa from 1,656 bromeliads in 26 field sites from Mexico to Argentina. We summarized invertebrate traits with four orthogonal axes, and used these trait axes to examine trait convergence and divergence assembly patterns along three environmental gradients: detrital biomass and water volume in bromeliads, and canopy cover over bromeliads. We found no overall signal of trait‐based assembly patterns along any of the environmental gradients. However, individual sites did show trait convergence along detrital and water gradients, and we built predictive models to explore these site differences. Sites that showed trait convergence along detrital gradients were all north of the Northern Andes. This geographical pattern may be related to phylogeographical differences in bromeliad morphology. Bromeliads with low detritus were dominated by detritivorous collectors and filter feeders, where those with high detritus had more sclerotized and predatory invertebrates. Sites that showed the strongest trait convergence along gradients in bromeliad water were in regions with seasonal precipitation. In such sites, bromeliads with low water were dominated by soft‐bodied, benthic invertebrates with simple life cycles. In less seasonal sites, traits associated with short‐term desiccation resistance, such as hard exoskeletons, were more important. In summary, we show that there are strong geographical effects on the trait‐based assembly patterns of this invertebrate community, driven by the biogeography of their foundational plant species as well as by regional climate. We suggest that inclusion of biogeography and climate in trait‐based community ecology could help make it a truly general theory. Read the free Plain Language Summary for this article on the Journal blog.

3D Assessment of Vine Training Systems Derived from Ground-Based RGB-D Imagery

In the field of computer vision, 3D reconstruction of crops plays a crucially important role in agriculture. On-ground assessment of geometrical features of vineyards is of vital importance to generate valuable information that enables producers to take the optimum actions in terms of agricultural management. A training system of vines (Vitis vinifera L.), which involves pruning and a trellis system, results in a particular vine architecture, which is vital throughout the phenological stages. Pruning is required to maintain the vine’s health and to keep its productivity under control. The creation of 3D models of vineshoots is of crucial importance for management planning. Volume and structural information can improve pruning systems, which can increase crop yield and improve crop management. In this experiment, an RGB-D camera system, namely Kinect v2, was used to reconstruct 3D vine models, which were used to determine shoot volume on eight differentiated vineyard training systems: Lyre, GDC (Geneva Double Curtain), Y-Trellis, Pergola, Single Curtain, Smart Dyson, VSP (Vertical Shoot Positioned), and the head-trained Gobelet. The results were compared with dry biomass ground truth-values. Dense point clouds had a substantial impact on the connection between the actual biomass measurements in four of the training systems (Pergola, Curtain, Smart Dyson and VSP). For the comparison of actual dry biomass and RGB-D volume and its associated 3D points, strong linear fits were obtained. Significant coefficients of determination (R2 = 0.72 to R2 = 0.88) were observed according to the number of points connected to each training system separately, and the results revealed good correlations with actual biomass and volume values. When comparing RGB-D volume to weight, Pearson’s correlation coefficient increased to 0.92. The results reveal that the RGB-D approach is also suitable for shoot reconstruction. The research proved how an inexpensive optical sensor can be employed for rapid and reproducible 3D reconstruction of vine vegetation that can improve cultural practices such as pruning, canopy management and harvest.

Co-firing의 위험분석 및 완화방안: 인도네시아 사례로부터

The co-firing program initiative in Indonesia involves mixing a portion of biomass into the coal that is being used for the operation of coal power plants. It is expected that biomass will replace 10% of the coal that currently is being used by 2025. Through robust risk analysis and appropriate mitigation plans, all of the challenges and obstacles that are encountered should be overcome, thereby achieving the desired goals of the renewable policy. This research assesses the risk of co-firing based on the empirical data of the coal powered plants in Indonesia. The two extreme risk factors of co-firing are identified as the discontinuous supply of the required volume of biomass and the low quality of the available biomass. The remaining risk factors, which are classified as moderate, are the technical efficiency, reliability, the cost of the fuel, environmental impact, the management of the Fly Ash Bottom Ash (FABA), and the decreasing quality of the biomass. We found that the greatest challenge in implementing co-firing power plants is not their technical readiness; rather, it is the development of the supply channel, using the advantage of the abundant local biomass potential. As such, risk mitigation measures are needed to sustain the supply of biomass for the long term and to ensure that the biomass is available at a competitive price to ensure that electricity can be supplied at an acceptable price.

Факторы, оказывающие влияние на численность и пространственное распределение жужелиц (Coleoptera, Carabidae) в агроценозах с разным уровнем интенсификации агротехнологий

This paper describes the results of data analysis on species composition and population of ground beetles (Coleoptera, Carabidae) in agrocenoses of spring wheat and corn at different levels of intensification in the forest-steppe of Western Siberia in the period of 2019-2021. The research was aimed at identifying correlating factors with the abundance of ground beetle communities and assessing their significance. The data analysis methods were specified with regard to the peculiarities of the structure and nature of the initial data distribution. Analysis of the population dynamics was performed for 20 species common and abundant for all agrocenoses (represented by dominants and subdominants). A position of the crop in the crop rotation was a significant factor for the agrocenoses of spring wheat, given that the distance from the steam increases the total biomass of vegetation due to weeds, as well as the number of pests, which probably forms more favorable conditions for the activity of ground beetles. Another correlation was also established between the index of dynamic density of ground beetles in wheat crops and the sum of active temperatures (t&gt;5 ºC), revealing the significant role of heat supply for poikilothermic organisms. The correlation between the index of dynamic density of ground beetles and the vegetation index NDVI values in corn pointed to the features of microclimate formation, given the biology of corn and the ability to build up a large volume of biomass already by mid-summer. No significant correlation between the technology of cultivation (level of intensification) and the dynamic density of ground beetles in agrocenoses was found. Therefore, the level of intensification (the use of crop protection agents and fertilizers regulated by the cultivation technology) does not have a significant effect on the number of ground beetles in the crops. Keywords: GROUND BEETLES, SPECIES DIVERSITY, COMMUNITY STRUCTURE, COMMUNITY DYNAMICS, AGROCENOSIS, INTENSIFICATION OF AGRICULTURAL TECHNOLOGY

Assessing Seagrass Restoration Actions through a Micro-Bathymetry Survey Approach (Italy, Mediterranean Sea)

Underwater photogrammetry provides a means of generating high-resolution products such as dense point clouds, 3D models, and orthomosaics with centimetric scale resolutions. Underwater photogrammetric models can be used to monitor the growth and expansion of benthic communities, including the assessment of the conservation status of seagrass beds and their change over time (time lapse micro-bathymetry) with OBIA classifications (Object-Based Image Analysis). However, one of the most complex aspects of underwater photogrammetry is the accuracy of the 3D models for both the horizontal and vertical components used to estimate the surfaces and volumes of biomass. In this study, a photogrammetry-based micro-bathymetry approach was applied to monitor Posidonia oceanica restoration actions. A procedure for rectifying both the horizontal and vertical elevation data was developed using soundings from high-resolution multibeam bathymetry. Furthermore, a 3D trilateration technique was also tested to collect Ground Control Points (GCPs) together with reference scale bars, both used to estimate the accuracy of the models and orthomosaics. The root mean square error (RMSE) value obtained for the horizontal planimetric measurements was 0.05 m, while the RMSE value for the depth was 0.11 m. Underwater photogrammetry, if properly applied, can provide very high-resolution and accurate models for monitoring seagrass restoration actions for ecological recovery and can be useful for other research purposes in geological and environmental monitoring.

Optimizing seed‐based Miscanthus plug plant production with supplemental heat and light, compost type and volume

AbstractTo help meet greenhouse gas mitigation targets perennial biomass crops will need to be planted at large scales and at a much greater pace over the coming decades. Miscanthus is a leading biomass crop but rapid upscaling is technically challenging due to costly and time‐consuming clonal propagation. Seed‐based hybrids are considered a viable route to rapid upscaling, but direct sowing has not been found feasible under temperate climate conditions due to high thermal requirements for germination and slow early plant development compared with larger seeded annuals. Seed‐based plug plants, initially propagated in greenhouses, provide a suitable route to improve field establishment. Here, we describe an input optimization experiment for seeded Miscanthus plugs raised for spring planting in a naturally lit greenhouse with the following treatments: supplemental heat to maintain a minimum of 15°C, supplemental predawn light from modern LEDs at PPFD 300–400 μmol m−2 s−1, two proprietary types of compost (known as 50k and 70k), and two compost volumes (35 and 15 cm3). Our results showed that variations in all four factors had significant effects on above‐ and belowground biomass: (i) supplemental heat increased root‐to‐shoot ratio, (ii) supplemental light increased total biomass and root‐to‐shoot ratio, (iii) compost type affected total biomass and (iv) compost volume was positively correlated with total biomass and stem base diameter. No factor had a significant effect on axillary shoot formation. We recommend nurseries in the United Kingdom use LEDs as predawn supplemental light but no supplemental heat, compost that has both good water‐holding capacity and aeration, and a larger compost volume, which provided optimized cost‐plug resilience for spring‐sown, seed‐based Miscanthus plug production.

Why Does Piscirickettsia salmonis Break the Immunological Paradigm in Farmed Salmon? Biological Context to Understand the Relative Control of Piscirickettsiosis

Piscirickettsiosis (SRS) has been the most important infectious disease in Chilean salmon farming since the 1980s. It was one of the first to be described, and to date, it continues to be the main infectious cause of mortality. How can we better understand the epidemiological situation of SRS? The catch-all answer is that the Chilean salmon farming industry must fight year after year against a multifactorial disease, and apparently only the environment in Chile seems to favor the presence and persistence of Piscirickettsia salmonis. This is a fastidious, facultative intracellular bacterium that replicates in the host’s own immune cells and antigen-presenting cells and evades the adaptive cell-mediated immune response, which is why the existing vaccines are not effective in controlling it. Therefore, the Chilean salmon farming industry uses a lot of antibiotics—to control SRS—because otherwise, fish health and welfare would be significantly impaired, and a significantly higher volume of biomass would be lost per year. How can the ever-present risk of negative consequences of antibiotic use in salmon farming be balanced with the productive and economic viability of an animal production industry, as well as with the care of the aquatic environment and public health and with the sustainability of the industry? The answer that is easy, but no less true, is that we must know the enemy and how it interacts with its host. Much knowledge has been generated using this line of inquiry, however it remains insufficient. Considering the state-of-the-art summarized in this review, it can be stated that, from the point of view of fish immunology and vaccinology, we are quite far from reaching an effective and long-term solution for the control of SRS. For this reason, the aim of this critical review is to comprehensively discuss the current knowledge on the interaction between the bacteria and the host to promote the generation of more and better measures for the prevention and control of SRS.

Macroalgal morphology mediates microplastic accumulation on thallus and in sediments

The accumulation process of microplastics (MPs) is a key to understanding their fate in the environment. However, there is limited information about the short-term accumulation of MPs on macrophytes. The ability of macrophyte to attenuate wave and reduce current velocity is potentially facilitating MPs deposition. We hypothesize that the macroalgae retain MPs with their morphologies (filamentous and non-filamentous) being one of the factors to govern retention. Our hypothesis was tested by field observation during the dry season in Hong Kong when the macroalgae communities were the most diverse. MPs per biomass, surface area, or interstitial volume were used to represent the abundances on macroalgae. We found that filamentous algae retained a 2.35 times higher number of MPs when compared with non-filamentous algae if unit per biomass was considered. Other units, however, showed insignificant differences in MPs abundances between algal morphologies. Fibre was the most dominant shape of MPs with no significant difference in their abundances between filamentous and non-filamentous algae, suggesting fibres were retained regardless of the algal morphologies. To further evaluate the potential accumulation in the environment, sediment samples were also collected under the algal mat and immediate vicinity (~50 cm) of the algal mat. We found that sediment collected under the vegetated area contained significantly higher MPs. This was 3.39 times higher than the unvegetated area. Sediment collected under/near filamentous algae retained much higher abundances of MPs than those of non-filamentous algae. Provided that the observed retention of MPs on macroalgae, we speculate macrophyte system is one of the short-term MPs accumulation hotspots where the temporal increase of MPs depends on the seasonality of macrophyte in a given region.

Алгоритм моделирования и визуализации роста дерева

The developed algorithm for modeling the growth of a tree using the example of European spruce (Picea abies) for three-dimensional visualization of plant development is presented. A special structure of classes is proposed that form the internal structure of a tree by a set of interconnected shoots that grow from buds. They store the numerical characteristics of the structure (age, trunk diameter, shoots length and the volume of tree photosynthetic biomass) and the spatial coordinates of structural elements on the parent object (last year’s shoot). The algorithm for modeling the growth of a spruce tree includes the generation of random values for the characteristics of shoots and buds. The proposed algorithm makes it possible to realize the structural diversity of branching processes and the stochastic nature of development under the conditions of tree growth in the Republic of Karelia.

Hybrid grid-tie electrification analysis of bio-shared renewable energy systems for domestic application

Increasing household energy demand in the countries of the global south and the lack of conventional fuels and their high prices is forcing local authorities to look for alternatives. Based on the example of the city of Gaza, the primary renewable energy sources are large volumes of biomass, particularly waste-derived, which causes environmental and health damage, as well as abundant amounts of solar radiation. Hybrid renewable energy system (HRES) of solar and biomass is proposed, providing sustainable electrification for highly populated communities. By reviewing the literature studies on the electrification systems consisting of biomass and solar energy systems in the Middle East and North Africa (MENA) countries, and with respect to the corresponding technologies applied, we decided to incorporate a biogas engine generator. Simulation experiments are conducted by HOMER Pro-software of the residential district average daily demand is about 1074 kWh/day, and peaks of 84.5 kWp. The grid-connected system utilises renewable resources through photovoltaic panels and a biogas generator. Pre-mathematical model to evaluate the system components capacities is provided with different zones of load profile to achieve optimum solution of the biomass contribution and reveals at least $2.30 M net present cost (NPC) and $0. 438/kWh cost of energy (CoE).

Co-gasification of biomass and coal in a top-lit updraft fixed bed gasifier: Syngas composition and its interchangeability with natural gas for combustion applications

The co-gasification of biomass and coal is a promising approach for efficiently integrating the unique advantages of different gasification feedstock with syngas production. Additionally, syngas from the co-gasification of locally available biomass and coal could supplement the natural gas used in household and industrial burners. The top-lit updraft gasifier features a moving ignition front that starts at the top and propagates downward through the solids bed, while air enters from the bottom and the gas product flows upwards. This study assesses the co-gasification performance of palm kernel shell and high-volatile bituminous coal in a top-lit updraft fixed bed gasifier using 70, 85, and 100 vol% biomass and equivalence ratios ranging from 0.26 to 0.34. The results indicate that the ignition front propagates faster and is more uniform as the biomass volume increases. Micro GC analysis revealed that the H2/CO ratio remained in the range of 0.57–0.59, 0.49–0.51, and 0.42–0.46 for experiments with 70, 85, and 100 vol% biomass, respectively. A gas interchangeability analysis showed that syngas-natural gas blends with up to 15 vol% of syngas could combust in atmospheric natural gas burners without modifications. Thus, the top-lit updraft gasifier shows excellent potential for the co-gasification of coal and biomass. Further research on this technology should explore steam as a gasification agent to enhance the syngas energy content and continuous solids feeding.

Oceanic Crustal Fluid Single Cell Genomics Complements Metagenomic and Metatranscriptomic Surveys With Orders of Magnitude Less Sample Volume.

Fluids circulating through oceanic crust play important roles in global biogeochemical cycling mediated by their microbial inhabitants, but studying these sites is challenged by sampling logistics and low biomass. Borehole observatories installed at the North Pond study site on the western flank of the Mid-Atlantic Ridge have enabled investigation of the microbial biosphere in cold, oxygenated basaltic oceanic crust. Here we test a methodology that applies redox-sensitive fluorescent molecules for flow cytometric sorting of cells for single cell genomic sequencing from small volumes of low biomass (approximately 103 cells ml–1) crustal fluid. We compare the resulting genomic data to a recently published paired metagenomic and metatranscriptomic analysis from the same site. Even with low coverage genome sequencing, sorting cells from less than one milliliter of crustal fluid results in similar interpretation of dominant taxa and functional profiles as compared to ‘omics analysis that typically filter orders of magnitude more fluid volume. The diverse community dominated by Gammaproteobacteria, Bacteroidetes, Desulfobacterota, Alphaproteobacteria, and Zetaproteobacteria, had evidence of autotrophy and heterotrophy, a variety of nitrogen and sulfur cycling metabolisms, and motility. Together, results indicate fluorescence activated cell sorting methodology is a powerful addition to the toolbox for the study of low biomass systems or at sites where only small sample volumes are available for analysis.

AGRICULTURE LAND AFFORESTATION WITH FAST-GROWING WOODY CROPS: ECONOMIC EVALUATION ACCORDING TO YIELDS OF PREVIOUS EXPERIMENTAL TRIALS

European Union (EU) aims to increase the share of renewable energy in total energy consumption in the next decades. The main renewable resource, which is mentioned in the policy documents, is biomass, especially wood biomass. Wood biomass for energy purposes could be successfully acquired from fast-growing woody plantations, growing on non-used agricultural lands. In Latvia, in 2019 were around 250 000 ha non-used agriculture land and part of it could be used for plantation growing. In Latvia, suitable woody species for use in plantations are willow, hybrid aspen, and grey alder. For economic calculations plantation site preparation before planting, planting, management, and biomass harvest costs were calculated, as well as revenues from selling biomass. In total 7 different plantation models were evaluated. Comparing the economic indicators for fast-growing woody crop plantation models during their cultivation and applying a discount rate of 7.63%, average service costs and product selling prices for the period 2015-2019, and under the existing plantation support system in 2021, intensively managed willow plantations, extensively managed willow plantations and hybrid aspen agroforestry plantations show positive accumulated cash flow. Hybrid aspen woody plantations and plantation forest, and grey alder energy wood and woody plantations show a negative accumulated cash flow, and their establishment in 2021 does not pay off. Factors that mostly affect plantation cash flow and therefore economic return are the biomass selling price and harvested biomass volume.

Optimum plant density and harvest age for maximizing productivity and minimizing competition in a Calliandra short-rotation-coppice plantation in West Java, Indonesia

To produce large volumes of biomass for implementing its green energy policy, the Government of Indonesia has issued a short rotation energy plantation program for a number of tree species including Calliandra calothyrsus (Meissn.). Optimum density and prompt harvesting are needed to maximise productivity, but information regarding both factors is insufficient. This study aimed to investigate the optimum growth spacing and ideal felling age to produce the largest volumes of biomass both economically and sustainably. Experiments were arranged on one hectare of land, which was divided into four plots with different plant spacing treatments (1 × 1.5 m; 1.5 × 1.5 m; 2 × 1.5 m; and 2 × 2 m). Growth and yield observations were carried out on plants aged 12, 18, and 24 months in each plot, with 30 sample trees left for growth observations and ten sample trees cut at each of the three ages after planting. This resulted in a total of 240 samples from the 2,710 trees planted. Trees were felled at 50 cm from the soil surface, and the resulting stools were left to regrow. A year after felling, resulting coppices, were observed and cut. Growth, productivity and calorific value were studied for both ‘primary’ and ‘coppiced’ wood. Study results demonstrate that competition between plants strongly determines the growth and productivity of ‘primary’ wood. The plot with the densest plant spacing had the lowest nutrient content for almost all soil nutrients. Higher plant density showed higher competition index values, and resulted in fewer and smaller diameter stems emerging from stools, and lower biomass productivity. Competition index values, which increased with plant age, can be used as an indicator for determining harvest timing. Productivity increased by up to 15% following development as a coppice plantation. Optimum wood productivity and greatest economy came from parent stands with plant spacing of 2 × 2 m, harvested at 18 months old and coppiced. This treatment yielded an average biomass/tree of primary wood 7.2 kg and coppice wood 8.22 kg, respectively, with lignin content of approximately 22%, and calorific value of around 18,807 kJ. These values match biomass energy requirements for feedstock for electricity generation. Harvesting at 24 months showed no significant increases in productivity, lignin content, or calorific value.

Mixed-Species Allometric Equations to Quantify Stem Volume and Tree Biomass in Dry Afromontane Forest of Ethiopia

Volume and biomass equations are essential tools to determine forest productivity and enable forest managers to make informed decisions. However, volume and biomass estimation equations are scarce for Afromontane forests in Africa in general and Ethiopia in particular. This limits our knowledge of the standing volume of wood, biomass, and carbon stock of the forests therein. In this study, we developed a new mixed-species volume and biomass equations for Afromontane forests and compared them with generic pantropical and local models. A total of 193 sampled trees from seven dominant tree species were used to develop the equations. Various volume and biomass equations were fitted using robust linear and nonlinear regression. Model comparison indicated that the best model to estimate stem volume was ln(v)=-9.909+ 0.954*ln(d2h), whereas the best model to estimate biomass was ln(b)=-2.983+ 0.949*ln(ρd2h) . These equations explained over 85% of the variations in the stem volume and biomass measurements. The mean density and basal area of trees in the forest with d ≥ 2 cm was 631.5 stems·ha-1 and 24.4 m2·ha-1. Based on the newly developed equations, the forest has on average 303.0 m3·ha-1 standing volume of wood and 283.8 Mg·ha-1 biomass stock. The newly developed allometric equations derived from this study can be used to accurately determine the stem volume, biomass, and carbon storage in the Afromontane forests in Ethiopia and elsewhere with similar stand characteristics and ecological conditions. By contrast, the generic pan-tropical and other local models appear to provide biased estimates and are not suitable for dry Afromontane forests in Ethiopia. The estimated stem biomass and carbon stock in the Chilimo forest are comparable with the estimates from various tropical forests and woodlands elsewhere in Africa, indicating the importance of dry Afromontane forest for climate change mitigation.

Cotton Bed Promotes Faster Growth and Higher Biomass Production of Mat-Forming Cyanobacterium &amp;lt;i&amp;gt;Oscillatoria&amp;lt;/i&amp;gt; sp.

The high biomass is the fundamental requisite for harnessing the commercial potentials of cyanobacteria. The present study demonstrates the faster production of high biomass of <i>Oscillatoria</i> sp. in the open-tray culture system. <i>Oscillatoria</i> sp. requires a suitable surface for forming its mat; therefore, initially, we have screened cotton, rice husk, gravels, and mud as supporting beds for the quicker growth of the <i>Oscillatoria</i> sp. Based on the expansion rate, the development of the <i>Oscillatoria</i> mat was the fastest on the cotton bed. Based on the result, the <i>Oscillatoria</i> mat grown on the cotton bed was superior in thickness, biomass quantity, and ability to produce phycocyanin to the naturally growing <i>Oscillatoria</i> mat. The <i>Oscillatoria</i> mat on the cotton bed was approximately 57.0% thicker than the naturally growing mat of <i>Oscillatoria</i> sp. Similarly, the Oscillatorial mat on the cotton bed generates almost double biomass and 15.0% higher phycocyanin content than that of the naturally growing mat of <i>Oscillatoria</i> sp. Finally, we compared four different harvesting methods, e. g. wiping, squeezing, centrifugation and vortexing with centrifugation for their efficiency to harvest the <i>Oscillatoria</i> biomass generated on the cotton bed. These four methods harvested more than 85.0% of the biomass of <i>Osciallatoria</i> sp., with more than 96.0% harvesting efficiency wiping was recorded as the most efficient harvesting method followed by vortexing and centrifugation with approximately 94.0% harvesting efficiency. The present findings suggest using the cotton bed as a supporting surface for the quick generation of a high volume of biomass of <i>Oscillatoria</i> sp. in the open culture system.

A mathematical model to study the dynamics of carbon capture in forest plantations

Fast-growing forest plantations play an important role in reducing global warming and have great potential for carbon capture. In this study, we aimed to model the dynamics of carbon capture in fast-growing plantations. A mathematical model is proposed consisting of a tridimensional nonlinear system. The variables involved are the amount of living biomass, the intrinsic growth of biomass, and the burned area by forestry fire. The environmental humidity is also considered, assumed as a parameter by simplicity. The solutions of the model are approximated numerically by the Runge-Kutta fourth-order method. Once the equilibria of the model have been obtained and its local stability determined, the analysis of the model reveals that the living biomass, as well as the stored carbon, decreases in each harvest cycle as a consequence of the negative effects of fire on soil properties. Furthermore, the model shows that the maximum area burned is attained always after the maximum volume of biomass is obtained. Numerical simulations show that the model solutions are reasonable for the growth dynamics of a plantation, from a theoretical perspective. The mathematical results suggest that a suitable optimal management strategy to avoid biomass losses in the successive regeneration cycles of the plantation is the prevention of fires together with soil fertilization, applied to fast-growing plantations.

Prediction of dasometric variables using linear mixed models and airborne LiDAR data

Adequate estimation of dasometric parameters such as basal area (AB), above-ground biomass (B), and timber volume (VOL) inmanaged forests is a primary requirement to quantify the role of forests in mitigation climate change mitigation. In this context,forest inventories represent the general technique to estimate dasometric parameters, however, they represent a greater consumptionof time and resources. Using data derived from remote sensors in the dasometric modeling offers huge possibilities as an auxiliarytool in forestry activities. The objective of this work was to obtain a statistical model for each forest variable of interest: basal area,above-ground biomass and timber volume in a temperate forest under management in Zacualtipán, Hidalgo, Mexico, using linearmixed models and LiDAR (Light Detection And Ranging) data as predictor variables. For this, we consider that the cluster samplingunits have spatial correlation with respect to them distributed independently in the field. Metrics derived from LiDAR data wereused to fit the models. The metrics related to height and density of the vegetation presented the highest Pearson correlations (r = 0.52- 0.86) with the different dasometric variables and these were used as predictors in the adjusted models. The results indicated thatthe random effect of the cluster and the use of variance function significantly improved the heteroscedasticity, since the spatialcorrelation of the sites was included. This work showed the potential of using linear mixed models to take advantage of thedependency between sites in the same cluster and improve traditional estimates that do not model this hierarchical relationship.

On the way to balance of forestry land use of Ukraine: ecological-and-economic aspect

Purpose. The purpose of this work is to investigate the ecological-and-economic aspect of certain factors to ensure the balanced use of forest lands; develop proposals for the formation of the basis for the development of sustainable forestry. &#x0D; Methodology / approach. We used the following methods: dialectical method of cognition for the analysis of scientific works of scientists concerning problems of balanced use of lands of forestry purpose; method of analogies (transfer of patterns of development of one process with certain amendments to another process or territory); statistical (based on quantitative indicators that allow drawing conclusions about the pace of the process); comparative analysis (comparison of indicators of forest resources and their use for Ukraine and Poland); correlation analysis (identification of factors on which the forecast significantly depends; clarification of relationships, their relationship with the predicted phenomenon under the influence of certain factors), graphical, abstract-logical (theoretical generalizations and formulation of conclusions). The information base of the study is the data of the Global Assessment of Forest Resources of FAO 2020, the data of the Monitoring of Land Relations in Ukraine, the reporting of the State Forest Agency of Ukraine, the data of the Forest Stewardship Council®. Based on the annual reports of the State Forestry Agency of Ukraine, some indicators of the report of 288 state forestries for 2018–2020 are consolidated in terms of 24 regional departments of forestry and hunting.&#x0D; Results. In the dynamics for 2018–2020, changes in the volume of forest resources, forest reserves, biomass, and carbon density were studied; the indicators of forest resources and their use for Ukraine and Poland are compared. The volumes of forest certification by regions of Ukraine are estimated. The relationships between capital investments in forestry production and the price of sold wood, the volume of net income of state forestry, the amount of profit, the degree of depreciation of fixed assets; between the tax burden on state forestries and financial stability was studied. Based on the assessment of the relationships and changes in individual indicators, the need to update the fixed assets of forest enterprises through the improvement of the investment instrument is justified. The results of this study are a summary of evidence on the environmental and economic aspects of the impact of certain factors on the sustainable use of forest lands, which in turn forms the scientific basis for achieving the goals of state environmental policy of Ukraine.&#x0D; Originality / scientific novelty. The studied interdependencies between the statistical characteristics of individual indicators of forestry land use made it possible to identify factors to ensure balanced use of forestry lands. It is substantiated that reforestation, forest certification, renewal of fixed assets of forestry enterprises through the improvement of the investment instrument, optimization of the tax burden of forestry activities are favorable factors to ensure the balance of forestry land use. It is proved that the excessive tax burden is a deterrent to the balanced use of forest lands. It is proposed to alleviate the tax burden on forestry activities by reducing the rate of deduction of net income of state forestry enterprises, eliminating the problem of double taxation of the forest fund, which under limited budget funding will allow state forestries to accumulate their own financial resources to ensure sustainable land use.&#x0D; Practical value / implications. The main results of the study can be used to: (I) structure the factors of sustainable use of forest lands; (II) defining the goals of sustainable development when developing the strategy of forestry enterprises; (III) analysis of the achievement of sustainable development goals at the national level, defined by the Basic Principles (strategy) of the state environmental policy of Ukraine for the period up to 2030. The results of the study can be used both at the level of forest management entities, as well as at the regional and national levels, to make management decisions on the implementation of measures that ensure the balanced use of forest land. Also, the causal links between indicators that arise from the response of indicators to certain factors open up new opportunities for forest management planning. These results can provide important information for the protection and use of forest resources in all regions of Ukraine.