Cone-Bearing Branches of Pinus koraiensis Are Not Carbon Autonomous during Cone Development

Cone development in conifer species is crucial to ensure sexual regeneration. A better understanding of carbon (C) source-sink relations at the branch level can guide strategies for improving resource allocation to reproduction. In particular, the evaluation of C relations between vegetative and reproductive branches is helpful to test whether tree branches are carbon autonomous. With this aim, we integrated girdling and defoliation treatments with 13C pulse labeling in situ to evaluate C autonomy in cone-bearing branches of P. koraiensis during the growing season. Girdling significantly reduced branch volumetric development, branch biomass, and non-structural carbohydrates across foliar, twig, and cone tissues; it also arrested cone development. Defoliation effects on these variables were minor, although they tended to increase with defoliation intensity. In addition, 13C increased by 4.5% and 45.4% after 4 h and 24 h of 13C labeling in unlabeled cone-bearing branches, respectively, indicating the C translocation from labeled vegetative branches. These results indicate that the cone-bearing branches are not C autonomous and that the development of female cones relies to a great extent on C import from neighboring branches. However, the amount of C translocated was largely dependent on manipulative alterations of the source-sink balance, thereby denoting extensive plasticity in the degree of branch C autonomy. These results shed light on the reproductive physiology of P. koraiensis.

Exploring the Potential to Improve the Estimation of Boreal Tree Structural Attributes with Simple Height- and Distance-Based Competition Index

In many cases, the traditional ground-based estimates of competition between trees are not directly applicable with modern aerial inventories, due to incompatible measurements. Moreover, many former studies of competition consider extreme stand densities, hence the effect of competition under the density range in managed stands remains less explored. Here we explored the utility of a simple tree height- and distance-based competition index that provides compatibility with data produced by modern inventory methods. The index was used for the prediction of structural tree attributes in three boreal tree species growing in low to moderate densities within mixed stands. In silver birch, allometric models predicting tree diameter, crown height, and branch length all showed improvement when the effect of between-tree competition was included. A similar but non-significant trend was also present in a proxy for branch biomass. In Siberian larch, only the prediction of branch length was affected. In Scots pine, there was no improvement. The results suggest that quantification of competitive interactions based on individual tree heights and locations alone has potential to improve the prediction of tree attributes, although the outcomes can be species-specific.

PENGARUH PEMUPUKAN N, P DAN K TERHADAP PRODUKTIVITAS DAN MUTU MINYAK Mentha arvensis

Mentha arvensis is an annual herbaceous plant that produces cornmint oil used for pharmaceutical and food industries. As a source of menthol and dimentolized oil, M. arvensis has a profitable opportunity to be cultivated in Indonesian agroclimate. The research was conducted to obtain the optimal dosages of N, P and K fertilizers, for increasing the yield and oil quality of M. arvensis, planted in Cicurug Research garden (latosol soil, 550 m asl.), by using randomized block design, with two factors, arranged factorially, with 3 replications. First factor was M. arvensis promising number (Mear 0010 and Mear 0012), and fsecond factor was NPK fertilizer, included: a). control, b). 69 kg N + 54 kg P2O5 + 94,5 kg K2O, c). 69 kg N + 72 kg P2O5 + 94,5 kg K2O, d). 69 kg N + 90 kg P2O5 + 94,5 kg K2O, e). 92 kg N + 90 kg P2O5 + 126 kg K2O, f). 92 kg N + 72 kg P2O5 + 126 kg K2O, and g). 138 kg N + 90 kg P2O5 + 126 kg K2O per ha. Variables observed were plant height, number of leaf and branch, biomass weight, oil content, free menthol content, and total menthol content. The results showed that application of 92 kg N + 72 kg P2O5 + 126 kg K2O/ha equivalent to 200 kg Urea+ 200 kg SP-36 + 200 kg KCl/ha to M. arvensis, resulted better herb biomass, oil content, total menthol content and oil yield at first harvest compared with other fertilizer treatments. At first harvest, oil and menthol yield were 41 and 25 kg / ha. The uptake of N, P, K nutrients were N > K > P, respectively.

Above-Ground Biomass Models of Caragana korshinskii and Sophora viciifolia in the Loess Plateau, China

The quantification of above-ground biomass is based on the calculation of carbon storage, which is important for the balance of carbon cycling. However, the allometric models of shrubs for calculating the above-ground biomass of shrubs in the Loess Plateau are scarce. In order to solve this issue, this study analyzed some highly correlated variables, including height (H), branch diameters (D), canopy volume (Cv), canopy area (Ca), and then built a regression model to predict the above-ground biomass in two common shrubs (Caragana korshinskii and Sophora viciifolia) in the Loess Plateau, China. The results show that the above-ground biomass of these two shrubs can be accurately predicted by H and D, and then we can use allometric model (y = axb) to calculate shrub above-ground biomass (including leaf biomass and branch biomass). Furthermore, the correlation between leaf biomass and branch biomass in Caragana korshinskii and Sophora viciifolia indicates that the components of above-ground biomass are closely related to each other. In addition, there is a strong linear relationship (p < 0.01) between the observed and estimated biomass values, which confirms the data accuracy of the above-ground biomass estimation models. In summary, these two biomass estimation models provide an accurate way to estimate the quantification of carbon for shrubs in the Loess Plateau.

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

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.

Methods for estimating aboveground biomass and its components for Douglas-fir and lodgepole pine trees

Estimating aboveground biomass and its components requires sound statistical formulation and evaluation. Using data collected from 55 destructively sampled trees in different parts of Oregon, we evaluated the performance of three groups of methods to estimate total aboveground biomass and (or) its components based on the bias and root mean squared error (RMSE) that they produced. The first group of methods used an analytical approach to estimate total and component biomass using existing equations and produced biased estimates for our dataset. The second group of methods used a system of equations fitted with seemingly unrelated regression (SUR) and were superior to the first group of methods in terms of bias and RMSE. The third group of methods predicted the proportion of biomass in each component using beta regression, Dirichlet regression, and multinomial log-linear regression. The predicted proportions were then applied to the total aboveground biomass to obtain the amount of biomass in each component. The multinomial log-linear regression approach consistently produced smaller RMSEs compared with both SUR methods. The beta and Dirichlet regressions were superior to both SUR methods except for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) branch biomass, for which the simple SUR method produced smaller RMSE compared with the beta and Dirichlet regressions.

ESTIMATING SINGLE TREE STEM AND BRANCH BIOMASS USING TERRESTRIAL LASER SCANNING

This paper presents a novel non-destructive approach for individual tree stem and branch biomass estimation using terrestrial laser scanning data. The study area is located at the Royal Belum Reserved Forest area, Gerik, Perak. Each forest plot was designed with a circular shape and contains several scanning locations to ensure good visibility of each tree. Unique tree signage was located on trees with diameter at breast height (DBH) of 10cm and above. Extractions of individual trees were done manually and the matching process with the field collected tree properties were relied on the tree signage and tree location as collected by total station. Individual tree stems were reconstructed based on cylinder models from which the total stem volume was calculated. Biomass of individual tree stems was calculated by multiplying stem volume with specific wood density. Biomass of individual was estimated using similar concept of tree stem with the volume estimated from alpha-hull shape. The root mean squared errors (RMSE) of estimated biomass are 50.22kg and 27.20kg for stem and branch respectively.

BRANCH DEVELOPMENT OF EUCALYPTS MANAGED FOR SAWLOGS

ABSTRACT Species of the genus Eucalyptus managed for sawlogs in fast-growing plantations show high potential for substitution for valuable native hardwoods. To obtain high quality wood, technical pruning is necessary. The objective of the study is to analyse the development of the branches for the first and second pruning lifts and to quantify the biomass of the pruned branches. For the study two stands of Eucalyptus grandis were selected (age 18 and 36 months) for evaluating a pruning lift from 0 to 3 m and 3 to 6 m. The average branch diameter and length were 18 mm and 2.1 m in the younger stand and 21 mm and 2.3 m in the older one. The relation between branch diameter and branch length could be expressed in a linear model (R² = 0.8). In both stands a higher proportion of branches were already dead. The oven-dry biomass of the pruned branches was 2.2 ton.ha-1 in the first pruning lift and 1.2 ton.ha-1 in the second. The results showed that branch development in wide spaced and early thinned eucalypt plantations is in line with the objective of high quality wood production. Pruning should take place before 18 month to avoid dead branches. The oven-dry branch biomass cut in the two pruning lifts shows a low volume making a commercial utilization difficult.