Estimation of Plant Height and Aboveground Biomass of Toona sinensis under Drought Stress Using RGB-D Imaging

Rapid and accurate plant growth and biomass estimation is essential for formulating and implementing targeted forest cultivation measures. In this study, RGB-D imaging technology was used to obtain the RGB and depth imaging data for a Toona sinensis seedling canopy to estimate plant growth and aboveground biomass (AGB). Three hundred T. sinensis seedlings from 20 varieties were planted under five different drought stress treatments. The U-Net model was applied first to achieve highly accurate segmentation of plants from complex backgrounds. Simple linear regression (SLR) was used for plant height prediction, and the other three models, including multivariate linear (ML), random forest (RF) and multilayer perceptron (MLP) regression, were applied to predict the AGB and compared for optimal model selection. The results showed that the SLR model yields promising and reliable results for the prediction of plant height, with R2 and RMSE values of 0.72 and 1.89 cm, respectively. All three regression methods perform well in the prediction of AGB estimation. MLP yields the highest accuracy in predicting dry and fresh aboveground biomass compared to the other two regression models, with R2 values of 0.77 and 0.83, respectively. The combination of Gray, Green minus red (GMR) and Excess green index (ExG) was identified as the key predictor by RReliefF for predicting dry AGB. GMR was the most important in predicting fresh AGB. This study demonstrated that the merits of RGB-D and machine learning models are effective phenotyping techniques for plant height and AGB prediction, and can be used to assist dynamic responses to drought stress for breeding selection.

Callus inducement of Toona sinensis: Potential agents against SARS-Corona virus replication

Bioprospecting of anti-SARS-corona virus phytochemical agents is an important issue today as an alternative to chemical drugs whose effectiveness has not been fully successful with no light effect. Quercetin, a component of Toona sinensis young leaves extract, was reported to have anti-viral activity against SARS-corona virus replication in vitro. Currently, the low efficiency of secondary metabolite production is an obstacle. Production of secondary metabolites from callus induction in vitro is considered more efficient and in a short time for commercial applications. The composition of hormones in callus media affects the secondary metabolites formed. The study was conducted to determine the effect of synthetic hormones auxin (BAP) and cytokinin (NAA) on callus percentage, fresh and dry callus cell weight and the average time of callus formation. The call percentage (100%) was obtained in different combinations of BAP and NAA in MS medium. The highest fresh weight of callus (165.50 gL−1) and dry cell weight (28.47 gL−1) were observed in MS medium (1.5 mgL−1 BAP and 1 mgL−1 NAA) within 7 days initial formation time of callus. The results showed that all the indices measured were positively correlated with callus induction in T. sinensis.

Ex-situ conservation through selection and breeding: A Review On 15 Years Toona sinensis Roem. & Toona sureni Merr. base populations

The ex-situ conservation of Toona sinensis and Toona sureni or surian weren’t supported list threatened species threat but by reduction of huge trees and leaving only small trees that are identical with the reduction of their genetic potential. Genetic potential plays a crucial role within the development of basic and breeding populations. The existence of the 15-year ex-situ conservation plot requires evaluation for simpler management to extend conservation value. The conservation area has collected genetic material from 52 populations from various islands in Indonesia and the progeny test area by testing 100 families from 10 selected populations because the basic source for assembling selected genetic material to supply superior seeds. Currently, genetic material from surian ex-situ conservation has been wont to develop genetic tests that are converted into seed orchards. Limitations of ex-situ conservation include maintenance of genetic material in artificial habitats, decreased genetic diversity, depression of close relative mating, adaptation to climate stress, and the potential for accumulation of weak alleles.it’s many constraints in terms of personnel, costs, and reliance on electrical power sources. supported the challenges within the future, efforts are needed to revamp through the unification of ex-situ conservation and progeny test management to support breeding population development. Strengthening the ex-situ conservation value of T. sinensis & T. sureni can be optimalization through solving all identified challenges and strengthening long-term management.

Shrub Diversity and Niche Characteristics in the Initial Stage of Reconstruction of Low-Efficiency Cupressus funebris Stands

The upper reaches of the Yangtze River are a very important ecological barrier in China, but the ecological benefits of large-scale Cupressus funebris Endl.plantations are low. This study investigated 12 plantations of different compositions and densities, including two densities of Cinnamomum septentrionale Hand.-Mazz. (Cs), Alnus cremastogyne Burk. (Ac), and Toona sinensis (A. Juss.) Roem. (Ts), and mixed plantations of Cs + Ac (CA), Ts + Cs (TC), Ts + Ac (TA), and Ac + Ts + Cs (ATC) and the cutting-blank (CB), and, at the same time, the unreconstructed pure C. funebris (Cf) forest was set as the control. We aimed to explore the influence mechanism of upper tree composition and density on shrub diversity, as well as the relationship between shrub diversity and niche. Our research results are as follows: (1) Among all the patterns, the TA, CA, and TC patterns are the most conducive to improving the diversity of shrubs. The composition and density of different trees have a great influence on the diversity of shrubs. (2) Niche is closely related to the diversity of shrubs. In the patterns of low niche overlap between dominant shrubs, the diversity of shrubs is greater. These results contribute to a deeper understanding of the relationship between the diversity of overstory and shrubs, and reveals the relationship between niche and diversity.

Investigation of Sound Absorption Properties of Heat-Treated Indonesian Momala (Homalium foetidum (Roxb.) Benth.) and Korean Red Toon (Toona sinensis (A. Juss.) M. Roem.) Cross Sections

This study investigates the effects of heat treatment time and presence of an air back cavity on the sound absorption performance of Indonesian momala (Homalium foetidum (Roxb.) Benth.) and Korean red toon (Toona sinensis (A. Juss.) M. Roem.) cross sections. To examine the porous characteristics of the two species before and after heat treatment, gas permeability, pore size, and porosity analyses were conducted. Additionally, the sound absorption coefficient was measured based on various heat treatment times and air back cavity sizes. The results showed that, with heat treatment at 210 °C for 6 h, the gas permeability improved by 4.3% for the momala and 38.5% for the red toon, the maximum pore size was improved by 5.25% in the momala and 26.0% in the red toon, and the through-pore porosity improved by 22.7% for the momala and 117.0% for the red toon. Due to these pore structure changes, the noise reduction coefficient (NRC) of the heat-treated momala improved by 6.8%. When a 3-cm air back cavity was applied to the heat-treated momala, the NRC was improved to 92.5%. Similarly, when the same air back cavity was applied to the heat-treated red toon, the NRC was improved to 190.7%. This study demonstrated that an increase in pore size and through-pore porosity by heat treatment triggered an increase in the sound absorption coefficient. Additionally, when an air cavity was applied, the sound absorption coefficient of both heat-treated wood species was increased at low frequency. From the results of this study, we expected that heat-treated momala and red toon cross-sections can be utilized as eco-friendly ceiling materials with sound absorption function.

Delignification Effects on Indonesian Momala (Homalium foetidum) and Korean Red Toon (Toona sinensis) Hardwood Pore Structure and Sound Absorption Capabilities

Among the various methods used to improve the sound absorption capability of wood, we focused on delignification in Indonesian momala (Homalium foetidum) and Korean red toon (Toona sinensis). We performed gas permeability, pore size, and porosity analyses and evaluated how the change in the pore structure affects the sound absorption capabilities. Results show that delignification increased the through-pore porosity and improved sound absorption capability in both species. In addition, the air gap in the rear space maximized the sound absorption of momala and the red toon. The noise reduction coefficient (NRC) of delignified momala (90 min) with a 3 cm air gap was 0.359 ± 0.023. This is approximately 154.6% higher than that of untreated momala without an air gap. The NRC of delignificated red toon (90 min) with a 3 cm air gap was 0.324 ± 0.040, an increase of 604.3% over untreated red toon without an air gap.