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Allometry, biomass and productivity in pinus massoniana forests of China: an updated review of published data

Jin Ling, Li Xiaodong, Huang Qiuchan, Yang Honglan, Huang Ju

Polish Journal of Ecology

2022

Vol. 70, nr 1

1--32

Field measurements of forest biomass are labor-consuming and usually destructive, but such direct datasets are the foundation for further developing indirect estimation such as biomass equation and biomass expansion factors that were used to scale biomass estimation or carbon storage from site or local surveys up to regional or national level. Pinus massoniana is widely distributed throughout 17 provinces of China and has a high economic value. This study is an updated review of the allometric equations, biomass allocation data and productivity estimations in Pinus massoniana forests of China published in articles during the period from 1982 to 2019. Different allometric equations of Pinus massoniana showed site-specific dependences. The aboveground and total tree biomass were expressed as power equations of mean age for Pinus massoniana forests. The mean value of aboveground tree biomass, total tree biomass and ecosystem biomass across all ages for Masson pine forests was 109.81, 127.65 and 138.76 Mg/ha, respectively. The mean proportion of stem, branch and foliage to aboveground tree biomass for Pinus massoniana was 77.1%, 15.9% and 7%, respectively. The tree root biomass continuously increased with the aboveground tree biomass and a power relationship was found between the tree root biomass and aboveground tree biomass for Pinus massoniana forests. The tree net primary productivity increased with aboveground tree biomass for Pinus massoniana forests, and the relationship was expressed as a linear equation. The mean tree, litter and ecosystem net primary productivity was 7.04, 4.88 and 8.30 Mg/ha/year, respectively. These findings provide key parameters for the biomass estimation and carbon accounting studies of widely planted Pinus massoniana forests in China.

Simulation analysis for optimal design of pneumatic bellow actuators for soft-robotic glove

Guo Ning, Sun Zhidao, Wang Xiaojun, Yeung Eric Hiu Kwong, To Michael Kai Tsun, Li Xiaodong, Hu Yong

Biocybernetics and Biomedical Engineering

2020

Vol. 40, no. 4

1359--1368

Soft actuators that have a bellows structure are favorable candidates for robots designed to interact with humans. However, a weak point in the actuator can occur as a result of deformation from the driving pressure. In this study, a simulation analysis of a soft bellows actuator composed of ethylene-vinyl acetate copolymer molding was conducted. The mechanical characteristics along different latitudes of the bellows in the soft actuator were evaluated using finite element modeling and analysis. Functional performance was studied during both compression and inflation using two driving methods (constant pumping rate-driven and constant displacement-driven). To validate the simulation, experimental tests were performed on a version of the soft bellows actuator that was constructed according to the same specifications as the model version; simulation and experimental displacements in relation to air pressure were compared. The results showed points near the trough were more likely to experience the largest stress during inflation and may suffer critical structural damage. During compression, points near the crest were more easily damaged. Stress variation showed good symmetry at points of interest on either side of the trough, during both inflation and compression. These findings provide a basis for precise control of and design improvements to soft bellows actuators for human-friendly usage.