Foliage Biomass Research Articles

Interactions among defoliation level, species, and soil richness determine foliage production during and after simulated spruce budworm attack

Defoliation level and site type are thought to influence tree response during spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks. We determined the effects of four manual defoliation treatments (0%, 50%, 100%, and 100% + bud removal of current foliage) for 3 years on foliage production of balsam fir (Abies balsamea (L.) Mill.), black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.), and white spruce (Picea glauca (Moench) Voss) trees on four site-quality classes. After 3 years of defoliation and 2 years of recovery, foliage biomass was reduced by 34%–98%. During defoliation, the number of shoots generally increased and shoot length of spruce generally decreased, especially on rich sites. During recovery, the number of shoots increased substantially, shoot length decreased, and bud destruction reduced the number of shoots by about 50% compared with that of trees that received the 100% defoliation treatment. Defoliation did not substantially affect needle length. Trees on rich sites had two- to fourfold greater foliage production than trees on poor sites. Effects of site and defoliation differed among species, but site quality, especially nutrition, played an important role in production of shoots and needles and the tree’s ability to withstand defoliation. Black spruce had more limited ability to recover foliage biomass, only producing more shoots, whereas balsam fir and white spruce had stronger ability to recover needle and shoot length, respectively.

Biomass, carbon and nitrogen in single tree components of grey poplar (Populus × canescens) in an uncultivated habitat in Van, Turkey.

The biomass, carbon and nitrogen storage in the single tree components (foliage, branch, crown, bark, stem and total aboveground) of the grey poplar (Populus × canescens) in its distribution in Eastern Anatolia (Van, Turkey) were determined and modelled. The biomass, carbon and nitrogen storages were not estimated at a stand level but were based on single trees. Regression models based on the tree diameter at breast height (DBH) and total tree height (H) were developed to estimate the biomass, carbon (C) storage and nitrogen (N) storage of the different tree components of a total of 28 grey poplar trees. The two main regression models in the power function were developed based only on the DBH (Model 1) and the combination of the DBH and height (D2H) (Model 2). All regression models, except for those of the foliage components, developed to estimate the biomass and C and N storages of the tree components were found to be statistically significant (p< 0.001). The partitioning of the total aboveground biomass in the bark, foliage, branches and stems was 0.7, 9, 17 and 73%, respectively. The average C concentrations of the tree components ranged from 48 (foliage) to 50% (bark, branch and stem), while the N concentrations ranged from 0.35 (stem) to 1.32% (foliage). Higher biomass and lower nitrogen concentrations of foliage compared with cultivated poplars were likely related to the natural site conditions, low soil nitrogen and/or characteristics of single tree growth.

Shifts in Foliage Biomass and Its Vertical Distribution in Response to Operational Nitrogen Fertilization of Douglas-Fir in Western Oregon

Nitrogen (N) fertilization is a commonly applied silvicultural treatment in intensively managed coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantations. Field trials were established in a randomized complete block design by Stimson Lumber Company (Gaston, Oregon), to test the economic viability of N fertilization on their ownership and to better understand Douglas-fir growth responses. The 23 stands comprising the trials were Douglas-fir dominated, had a total age of 16–24 years, had been precommercially thinned, and had a density of 386–1021 trees ha−1. Fertilizer was applied aerially at a rate of 224 kg N ha−1 as urea during the 2009–2010 dormant season. In the dormant season of 2016–2017, seven growing seasons following application, 40 trees were felled and measured with the objective of assessing crown attributes and aboveground allometrics. Branch-level foliage mass equations were developed from 267 subsampled branches and were applied to the 40 felled sample trees on which the basal diameter and height of all live branches were measured, allowing estimation of both the total amount of foliage and its vertical distribution. A right-truncated Weibull distribution was fitted to data, with the truncation point specified as the base of live tree crown. The resulting tree-level parameter estimates were modeled as functions of tree-level variables. Stand-level factors not explicitly measured were captured through the use of linear and nonlinear mixed-effects models with random stand effects. Fertilization resulted in more total crown foliage mass in the middle crown-third and caused a downward shift in the vertical distribution of foliage, with implications for feedback responses in crown development and photosynthetic capacity. Defining the morphological responses of Douglas-fir crowns to nitrogen fertilization provides a framework for studying influences on stand dynamics and should ultimately facilitate improved site-specific predictions of stem-volume growth.

Carbon and Macronutrient Budgets in an Alder Plantation Grown on a Reclaimed Combustion Waste Landfill

Combustion waste landfills are unfavorable for revegetation due to nitrogen deficiency, and therefore, the introduction of nitrogen-fixing organisms, such as alder species (Alnus sp.), may be promising for reclamation and restoration of these sites. We investigated the carbon and macronutrient stocks in the combustion waste technosols and biomass of black alder (Alnus glutinosa) and grey alder (Alnus incana) 10 years after introduction onto a combustion waste landfill. The alder species were planted with or without lignite addition in planting holes, the latter acting as control plots. Black alder biomass was higher than that of grey alder. The total macronutrient stocks were higher in the uppermost technosol layer (0–30 cm) than in the biomass nutrient stocks. However, the K and P stocks in the black alder biomass were still greater than the exchangeable K+ and available phosphorus (Pav) stocks in technosols. This is important for the nutrition of the trees planted in combustion waste landfills and confirms the Pav deficit in investigated technosols. The differentiation of nutrients in biomass shows that the largest stock was found in the wood of trunks and branches (40–70% of the stock of individual biomass macronutrients). Although foliage biomass represented approximately 7% of the total tree biomass, the nutrient stocks therein represented a significant proportion of total nutrient stocks: approximately 27–29% nitrogen, 17–22% calcium, 28% magnesium, 7–10% potassium and 12–16% phosphorus. This is particularly important in the context of the turnover of nutrients from litterfall and soil organic matter and the circulation of nutrients in the ecosystem developed on combustion waste technosols.

Correction: Scots pine and Norway spruce foliage biomass in Finland and Sweden — testing traditional models vs. the pipe model theory

Correction: Scots pine and Norway spruce foliage biomass in Finland and Sweden — testing traditional models vs. the pipe model theory

Seemingly Unrelated Mixed-Effects Biomass Models for Young Silver Birch Stands on Post-Agricultural Lands

Secondary succession that occurs on abandoned farmlands is an important source of biomass carbon stocks. Both direct and indirect tree biomass estimation methods are applied on forest lands. Using empirical data from 148 uprooted trees, we developed a seemingly unrelated mixed-effects models system for the young silver birch that grows on post agricultural lands in central Poland. Tree height, biomass of stem, branches, foliage, and roots are used as dependent variables; the diameter at breast height is used as the independent variable. During model elaboration we used restricted cubic spline: 5 knots at the quantiles (0.05, 0.275, 0.5, 0.725, and 0.95) of diameter at breast height provided sufficiently flexible curves for all biomass components. In this study, we demonstrate the use of the model system through cross-model calibration of the biomass component model using tree height measured from 0, 2, 3, and 4 available extreme trees feature in the plot in question. A different number of extreme trees were measured for final model system and our results indicated that for all analyzed components, random-effect predictions are characterized by higher accuracy than fixed-effects predictions.

Scots pine and Norway spruce foliage biomass in Finland and Sweden — testing traditional models vs. the pipe model theory

The pipe model approach was compared with foliage biomass models by using the cross-sectional area at the tree crown base for predicting foliage biomass of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). We evaluated the impacts of site type, fertilization, and climate on the relationship between foliage biomass and cross-sectional area at the tree crown base, referred as to the pipe model ratio. Our hypotheses were that (i) the pipe model approach is a more precise and accurate method for foliage prediction than the traditional biomass models and (ii) the pipe model ratio for foliage does not explicitly depend on any single environmental driver. Data used here consisted of felled trees from Finnish and Swedish biomass studies. These data were analyzed by linear mixed models with different covariates, and the uncertainties of different modelling approaches were evaluated. The pipe model outperformed other models for Scots pine but not for Norway spruce. Results showed larger pipe model ratios for Scots pine in herb-rich forests compared with those of trees in subxeric heath forest. Results from fertilized trees indicated that the addition of nitrogen temporarily increased foliage biomass.

Rising CO2 in the field does not offset warming or drought constraints on leaf growth of a C3 forage

AbstractThe regrowth of a C3 forage Stylosanthes capitata in a rain-fed field provided the weekly data collection in the southeast of Brazil during a heat event in autumn. A system named Trop-T-FACE simulated the free-air carbon dioxide enrichment and the enhanced temperature in four climatic regimes: current atmospheric conditions (Control), CO2 enrichment (600 ppm, eC), warming (2 °C above ambient canopy temperature, eT), and a combination of eC + eT. The area and biomass of foliage per shoot decreased, and the number of flowers per shoot and flowered ramification increased under single eC treatment besides the increment in palisade parenchyma of leaves. Increased investment in flowering in eC occurred notably when the soil water content was higher than 0.30 m3 m–3. Single eT treatment also impaired the area or biomass of foliage production per shoot, raised the shoot mortality, and promoted the increment of the spongy leaf parenchyma. There was some mitigation of the adverse effects of foliage production of eT or eC in eC + eT, but under this combined treatment, the shoot mortality also increased. Changes in leaf tissues under eC or eT or some mitigation of adverse effects in eC + eT did not offset the constraints on leaf growth per shoot. The harmful impact on foliage production by eC, eT, or eC + eT under rain-fed conditions indicated no advantages for feeding the livestock with the C3 forage S. capitata in expected climate change under field conditions.

Improving models of fine root carbon stocks and fluxes in European forests.

Fine roots and above‐ground litterfall play a pivotal role in carbon dynamics in forests. Nonetheless, direct estimation of stocks of fine roots remains methodologically challenging. Models are thus widely used to estimate these stocks and help elucidate drivers of fine root growth and turnover, at a range of scales.We updated a database of fine root biomass, necromass and production derived from 454 plots across European forests. We then compared fine root biomass and production to estimates obtained from 19 different models. Typical input variables used for the models included climate, net primary production, foliage and above‐ground biomass, leaf area index (LAI), latitude and/or land cover type. We tested whether performance could be improved by fitting new multiple regression models, and explored effects of species composition and sampling method on estimated fine root biomass.Average fine root biomass was 332 g/m2, and necromass 379 g/m2, for European forests where the average fine root production was 250 g m−2 year−1. Carbon fraction in fine roots averaged 48.4%, and was 1.5% greater in broadleaved species than conifers.Available models were poor predictors of fine root biomass and production. The best performing models assumed proportionality between above‐ and below‐ground compartments, and used remotely sensed LAI or foliage biomass as key inputs. Model performance was improved by use of multiple regressions, which revealed consistently greater biomass and production in stands dominated by broadleaved species as well as in mixed stands even after accounting for climatic differences. Synthesis. We assessed the potential of existing models to estimate fine root biomass and production in European forests. We show that recalibration reduces by about 40% errors in estimates currently produced by the best available models, and increases three‐fold explained variation. Our results underline the quantitative significance of fine roots (live and dead) to the global carbon cycle.

Продукція фітомаси надземної частини робінієвих деревостанів у лісових культурах Північного Степу України

Поточний об'ємний приріст деревини стовбурів і продукція компонентів фітомаси надземної частини насаджень Robinia pseudoacacia L. визначено для модальних деревостанів, які характеризуються такими таксаційними показниками: A = 3-82 р., D1,3 = 3,9-24,8 см, H = 5,2 -21,5 м, P = 0,1-1,15.&#x0D; Як вхідні аргументи регресійних рівнянь використано таксаційні показники робінієвих деревостанів. Розраховані регресійні алометричні моделі оцінювання фітомаси деревини і кори стовбурів, фітомаси компонентів крони – деревини і кори гілок, фітомаси листкі, поточного об'ємного приросту за запасом. Коефіцієнти детермінації рівнянь (0,24-0,96) не перевищують їх критичного значення. Найбільш значущою визначено пʼятифакторну модель, яка враховує вік, середній діаметр, середню висоту головної породи, запас і відносну повноту насадження.&#x0D; Розрахунок продукції деревини стовбурів робінієвих насаджень здійснено через оцінювання поточного приросту за запасом і середньої базисної щільності деревини стовбурів робінії, яка становить 499,8 кг (м3)-1. Наведено нормативи продукції стовбурової деревини у межах значень середнього діаметра деревостану від 4 до 28 см і запасу стовбурової деревини від 20 до 180 м3∙га-1.&#x0D; Продукція стовбурової деревини зі збільшенням середнього діаметра деревостану зменшується, а зі збільшенням запасу за умови однакового значення діаметра – збільшується. У віковій структурі робінієвих насаджень Північного Степу домінує група перестиглих деревостанів, для яких у діапазоні середніх діаметрів 14-24 см продукція стовбурової деревини становить 1,73-2,69 т∙га-1∙рік-1.&#x0D; Загальну продукцію фітомаси надземної частини робінієвих деревостанів лісогосподарських підприємств Державного агентства лісових ресурсів України у Дніпропетровській області оцінено в 138,3 тис. т∙рік-1.

Similar Impacts of Alien and Native Tree Species on Understory Light Availability in a Temperate Forest

Research Highlights: We evaluated influence of alien and native trees and shrubs on stand leaf area index to basal area ratio, indicating that both groups provide similar amounts of foliage. Background and Objectives: Foliage traits determine tree species effect on understory light availability. Direct comparisons of understory light availability due to different foliage traits of tree species are conducted less often at the stand level. We hypothesized that light availability is driven by canopy leaf area, and alien species contribution to canopy foliage will be similar to native species due to analogous patterns of biomass allocation in tree species. Materials and Methods: We studied forests dominated by alien and native tree species in Wielkopolski National Park (Western Poland). We measured light availability using the LAI-2200 canopy analyzer (Li-Cor Inc., Lincoln, NE, USA) and we calculated leaf area index (LAI) in 170 stands using published models of foliage biomass and data on specific leaf area. Results: Our study confirmed an impact of LAI on light availability in the understory layer. Analyzing the proportion of contribution to stand LAI and basal area (BA) we found that most alien species did not differ in LAI to BA ratio from native species. The exception was Prunus serotina Ehrh., with a LAI to BA ratio higher than all native and alien trees. However, the highest LAI to BA ratios we found were for the alien shrub Cotoneaster lucidus Schltdl. and native shrubs of fertile broadleaved forests. Conclusions: Our study showed that alien species contribution to shading the understory is comparable to native species, with the exception of P. serotina due to its dominance in the higher shrub canopy strata where it exhibits different patterns of biomass allocation than native trees. Our study explained that invasive tree species impact on light availability in forest ecosystems is mainly mediated by the increased quantity of foliage, not by more effective LAI to BA ratio.

Evaluation of Macaranga tanarius as a biomass feedstock for fermentable sugars production

Macaranga tanarius is a fast-growing tree species that could be potentially utilized as a biomass feedstock for biorefinery. The average productivity of M. tanarius biomass was estimated to be ~19.2 ton/ha if the above-ground biomass is harvested bi-annually. Different pretreatment approaches were investigated to increase the enzymatic digestibility of foliage and woody biomass. The results indicated that no pretreatment was required for the foliage biomass while sequential acid/alkali pretreatment was necessary for the woody biomass before enzymatic hydrolysis. For the woody biomass, the delignification was 34.5% after sequential dilute acid/alkali pretreatment. The reducing sugar yields from enzymatic hydrolysis of foliage and pretreated woody biomass were 0.31 and 0.42 g/g dry biomass, respectively. The results also showed that both hydrolysates were fermentable by lactic acid bacteria. Overall, the results suggested that M. tanarius could be a potential feedstock for biorefinery based on the findings and processes derived from this study.

Allometric Equations for Estimating the Above-Ground Biomass of Five Forest Tree Species in Khangai, Mongolia

Understanding the contribution of forest ecosystems to regulating greenhouse gas emissions and maintaining the atmospheric CO2 balance requires the accurate quantification of above-ground biomass (AGB) at the individual tree species level. The main objective of this study was to develop species-specific allometric equations for the total AGB and various biomass components, including stem, branch, and foliage biomass in Khangai region, northern Mongolia. We destructively sampled a total of 183 trees of five species (22–74 trees per species), including Siberian stone pine (Pinus sibirica Du Tour.), Asian white birch (Betula platyphylla Sukacz.), Mongolian poplar (Populus suaveolens Fisch.), Siberian spruce (Picea obovata Ldb.), and Siberian larch (Larix sibirica Ldb.), across this region. The results showed that for the five species, the average biomass proportion for the stems was 75%, followed by branches at 20% and foliage at 5%. The species-specific component and total AGB models for the Khangai region were developed using tree diameter at breast height (D) and D² and tree height (H) combined ( D 2 H ); and both D and H were used as independent variables. The best allometric model was lnŶ = lna + b × lnD + c × lnH for the various components and total AGB of B. platyphylla and L. sibirica, for the stems and total AGB of P. suaveolens, and for the stem and branch biomass of P. obovata. The equation lnŶ = lna + b × ln( D 2 × H ) was best for the various components and total AGB of P. sibirica, for the branch and foliage biomass of P. suaveolens, and for AGB of P. obovata. The equation lnŶ = lna + b × ln(D) was best only for the foliage biomass of P. obovata. Our results highlight that developing species-specific tree AGB models is very important for accurately estimating the biomass in the Khangai forest region of Mongolia. Our biomass models will be used at the tree level inventories with sample plots in the Khangai forest region.

Efectividad de hongos micorrízicos arbusculares nativos de rizósfera de Agave como promotores de crecimiento de papaya

Arbuscular mycorrhizal fungi (AMF) are benef icial symbionts of most terrestrial plants. This symbiosis brings benef its to both symbionts. The plant involved in the symbiosis is supplied with nutrients by the fungus that promotes plant growth, in exchange for energy for reproduction of the AMF. In this context, the effectiveness of multi-specif ic AMF inocula from the rhizosphere of Agave cupreata from Michoacán, Mexico, in promoting the growth of papaya plants was evaluated. An experiment was carried out in ten random blocks with eleven treatments: eight consortiums of AMF, a commercial biofertilizer based on AMF (EndoMic®), a reference strain (Claroideoglomus claroideum) and a control without AMF. One hundred days after establishing the experiment, we evaluated the variables plant height, stem diameter, dry biomass of foliage, root and total, foliar area, relative index of mycorrhizal dependence, mycorrhizal colonization and density of mycorrhizal spores. The data were analyzed through an analysis of variance and correlation. The results showed that two of the consortiums promoted plant growth eff iciently; the plants inoculated with the consortiums AD-MTu and CM-MT signif icantly increased (Tukey, P ≤ 0.05) dry biomass by 240 and 225%, respectively, relative to the control without AMF, while with the biofertilizer EndoMic® the increase for the same variable was only 12%. It is concluded that the use of consortiums of AMF promotes the growth of papaya and therefore could be used in nurseries or greenhouses.

Partitioning and predicting forage biomass from total aboveground biomass of regenerating tree species using dimensional analyses

Foresters and wildlife biologists use biomass estimates as proxies of habitat structure, productivity, and carrying capacity. Determining biomass, however, is challenging without destructive harvests. We provide a dimensional analysis approach to partition browse biomass (BB) from total aboveground biomass (AGB) of six regenerating hardwoods in the Allegheny forests of Pennsylvania, USA. First, we determined the average diameter of browsed twigs for each species. Then, we created a subset of potential browsable twig and foliage biomass from total AGB in 439 individuals harvested within paired exclosure (fenced) and control (unfenced) plots at 15 sites. We fit species-specific allometric equations to estimate BB and AGB using basal diameter and height as predictors and tested the effects of fencing. Although overall stem height and BB were greater within exclosures, fencing did not significantly affect relationships between either predictor and BB or AGB, thereby enabling general and robust (R2 ≥ 0.80) equations for most species. Our work provides biomass equations for regionally dominant species and size classes that are underrepresented in the literature, yet critical to forest renewal and wildlife. Moreover, by sampling variable sites and levels of browse pressure, reported equations lessen site-specific biases. Finally, our methodology provides a template to generate forage biomass prediction equations for other plant and ungulate species.

Biomass Accumulation and Carbon Sequestration in an Age-Sequence of Mongolian Pine Plantations in Horqin Sandy Land, China

The Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) was first introduced to the southeastern Horqin sandy land in the mid-1950s. Since then, it has been widely planted and has become the most important conifer species in Northern China, providing significant ecological, economic and social benefits. However, its function in sequestering carbon at different developmental stages has been little studied. In this study, twenty plots inventory and destructive sampling of eight trees were conducted in 12-, 19-, 34-, 48- and 58-year-old Mongolian pine stands of China. Allometric biomass equations (ABEs) for tree components were established and used to determine the magnitude and distribution of tree biomass and carbon density. The carbon density of the understory, forest floor and soil was also determined. The ABEs with age as the second variable could simply and accurately determine the biomass of plantation tree branches, foliage and fruit, which were considerably influenced by age. With increasing stand age, the proportion of stem biomass to total tree biomass increased from 22.2% in the 12-year-old stand to 54.2% in the 58-year-old stand, and the proportion of understory biomass to total ecosystem biomass decreased, with values of 7.5%, 4.6%, 4.4%, 4.1% and 3.0% in the five stands. The biomass of the forest floor was 0.00, 1.12, 2.04, 6.69 and 3.65 Mg ha−1 in the five stands. The ecosystem carbon density was 40.2, 73.4, 92.9, 89.9 and 87.3 Mg ha−1 in the 12-, 19-, 34-, 48-, and 58-year-old stands, in which soil carbon density accounted for the largest proportion, with values of 67.4%, 76.8%, 73.2%, 63.4%, and 57.7% respectively. The Mongolian pine had the potential for carbon sequestration during its development, especially in the early stages, however, in the later growth stage, the ecosystem carbon density decreased slightly.

Estimating canopy structure and biomass in bamboo forests using airborne LiDAR data

The Bamboo species accounts for almost 1% of the Earth’s forested area with an exceptionally fast growth peaking up to 7.5–100 cm per day during the growing period, making it an unique species with respect to measuring and monitoring using conventional forest inventory tools. In addition their widespread coverage and quick growth make them a critical component of the terrestrial carbon cycle and for mitigating the impacts of climate change. In this study, the capability of using airborne Light Detection and Ranging (LiDAR) data for estimating canopy structure and biomass of Moso bamboo (Phyllostachys pubescens) was assessed, which is one of the most valuable and widely distributed bamboo species in the subtropical forests of south China. To do so, we first evaluated the accuracy of using LiDAR data to interpolate the underlying ground terrain under bamboo forests and developed uncertainty surfaces using both LiDAR-derived vegetation and topographic metrics and a Random Forest (RF) classifier. Second, we utilized Principal Component Analysis (PCA) to quantify the variation of the vertical distribution of LiDAR-derived effective Leaf Area Index (LAI) of bamboo stands, and fitted regression models between selected LiDAR metrics and the field-measured attributes such mean height, DBH and biomass components (i.e., culm, branch, foliage and aboveground biomass (AGB)) across a range of management strategies. Once models were developed, the results were spatially extrapolated and compared across the bamboo stands. Results indicated that the LiDAR interpolated DTMs were accurate even under the dense intensively managed bamboo stands (RMSE = 0.117–0.126 m) as well as under secondary stands (RMSE = 0.102 m) with rugged terrain and near-ground dense vegetation. The development of uncertainty maps of terrain was valuable when examining the magnitude and spatial distribution of potential errors in the DTMs. The middle height intervals (i.e., HI4 and HI5) within the bamboo cumulative effective LAI profiles explained more variances by PCA analysis in the bamboo stands. Moso bamboo AGB was well predicted by the LiDAR metrics (R2 = 0.59–0.87, rRMSE = 11.92–21.11%) with percentile heights (h25-h95) and the coefficient of variation of height (hcv) having the highest relative importances for estimating AGB and culm biomass. The hcv explained the most variance in branch and foliage biomass. According to the spatial extrapolation results, areas of relatively low biomass were found on secondary stands (AGB = 49.42 ± 14.16 Mg ha−1), whereas the intensively managed stands (AGB = 173.47 ± 34.16 Mg ha−1) have much higher AGB and biomass components, followed by the extensively managed bamboo stands (AGB = 67.61 ± 13.10 Mg ha−1). This study demonstrated the potential benefits of using airborne LiDAR to accurately derive high resolution DTMs, characterize vertical structure of canopy and estimate the magnitude and distribution of biomass within Moso bamboo forests, providing key data for regional ecological, environmental and global carbon cycle models.

Basic density and crown parameters of forest forming species within Steppe zone in Ukraine

Abstract The parameters of wood density (WD), bark density (BD) and tree crown characteristics are not only important for estimation of the aboveground biomass, but they also serve as indicators for the timber quality. This study had two objectives: Black locust (Robinia pseudoacacia L.) – an introduced species; Scots pine (Pinus sylvestris L.) – an aboriginal species. Black locust and Scots pine from the Steppe zone in Ukraine were compared in their WD and BD, and in the morphological parameters of their tree crowns. There were determined basic WD and BD for differently aged individuals of Black locust and Scots pine. Generally, a higher WD was found for Black locust trees. The average Black locust WD was 518 kg m−3, ranging from 375 kg m−3 to 612 kg m−3; with the average BD – 294 kg m−3, ranging from 214 kg m−3 to 421 kg m−3. The average Scots pine WD was 414 kg m−3, ranging from 254 to 491 kg m−3; with average BD – 317 kg m−3, ranging from 178 to 433 kg m−3. The dependences between WD, BD and biometric tree parameters were identified by correlation analysis. The crown diameter for Black locust and Scots pine was described with fixed prediction models. We proposed particular equations for relationships between foliage biomass and branch biomass, derived from the crown volume of the investigated species.

Research into Influence from Different Ranges of PAR Radiation on Efficiency and Biochemical Composition of Green Salad Foliage Biomass

Results of the first photobiological studies of optimisation of LED phyto irradiators spectrum and irradiance level, when growing salad­greengrocers plants in greenhouses and plant factories in photoculture conditions, are presented in the article. The results are given as a series of producing capacity curves for salad and basil plants when irradiating by quasi­monochromatic spectrum for three PAR ranges: blue, green and red. In the experiment, levels of photosynthetic photon irradiance (70 ? 230) µmol/s·m2 and of irradiance (13 ? 60) W/m2 were varied within a wide range. “Rough” spectra of optical radiation action estimated over producing capacity of plants with different irradiance levels are given, and questions of additivity of different spectral radiation influence in forming vegetable biomass are considered. Evaluations of efficiency of various PAR intervals for synthesis of biochemical combinations determining nutrition facts of the studied cultures are performed.

Carbon stocks in biomass and soils of woody species fodder banks in the dry tropics of Mexico

AbstractUnderstanding carbon (C) dynamics of the silvopastoral systems can help mitigate greenhouse gas emissions. The aim of this study was to evaluate the C concentration and storage in above‐ and belowground tree biomass as well as in the soils of fodder banks of Leucaena leucocephala (Lam.) de Wit, Guazuma ulmifolia (Lam.) or a combination of the both species. The above‐ and belowground biomass was quantified by the destructive sampling. We also obtained samples from soil pits, 20‐cm deep, and determined bulk density and organic carbon concentration. The mixed species banks produced more foliage dry matter (DM) (6.3 t DM/ha) than the pure fodder banks. The total living biomass stocks ranged from 31.5 to 33.5 t DM/ha and did not differ between fodder bank types. The tissue C concentration was greater in stems (45.1%) and roots (44.9%) compared to the foliage component (43.4%). Total soil carbon (TSC) in the 5–10 cm layer was greater in the fodder banks with legumes alone than in mixed species banks (35.7 vs. 30.8 t C/ha). TSC storage in the 15–20 cm layer was greater in the nonlegume fodder bank than in the legume fodder bank (39.8 vs. 34.5 t C/ha). However, to the 0–20 cm layer, TSC was similar for all fodder banks. Thus, the three types of fodder banks had similar total C storage in plant biomass and soil, but the production of foliage biomass was higher in the mixed species banks.