Secondary xylem maturation evaluated by modeling radial variations in anatomical characteristics and wood properties of Shorea macrophylla (De Vr.) Ashton planted in Sarawak, Malaysia

Radial variations in anatomical characteristics and wood properties were investigated in 23-year-old Shorea macrophylla (engkabang) trees planted in Sarawak, Malaysia. The efects of radial growth rates on anatomical characteristics and wood properties and the manner of xylem maturation were determined based on selected mixed-efects models. The best models of radial variation were ftted by linear functions for wood fber length, wood fber wall thickness, basic density, and compressive strength. Logarithmic functions were applied for vessel element length and vessel frequency, and quadratic functions were applied for vessel diameter and wood fber diameter. Vessel diameter and wood fber length were afected by radial growth rates although these efects on the other properties were minimal. In the fxed part of the models, the results showed small mean absolute error values of radial variation in relation to the distance from the pith according to vessel frequency and vessel diameter. In contrast, in relation to the estimated cambial age, smaller mean absolute error values were obtained for cell length, wood fber traits, and basic density, suggesting that all properties varied from pith to bark in relation to the cambial age, except for vessel traits. Thus, in S. macrophylla, xylem maturation in cell length, wood fber traits, and basic density were due to cambial age rather than diameter growth, but xylem maturation in vessel traits depended on diameter growth

Basic wood properties of Borneo ironwood (Eusideroxylon zwageri) planted in Sarawak, Malaysia

The aim of this study is to obtain the basic wood properties of planted Borneo ironwood (Eusideroxylon zwageri) from a plantation established about 80 years ago. Stem diameter at 1.3 m above the ground, tree height, and stress-wave velocity (SWV) of stem were measured on 36 planted E. zwageri trees. Later, core samples were collected from four trees whose measurements represented the average stem diameter of all the measured trees. Using the core samples, the moisture content (MC), basic density (BD), and compressive strength parallel to grain (CS) were measured. Dynamic Youngʼs modulus for longitudinal direction at green condition (E) was also calculated from SWV. There was no significant relationship between growth characteristics and SWV. Mean values of MC, BD, CS, and E were 37.2 %, 0.86 g/cm3 , 64.3 MPa, and 18.47 GPa, respectively. Significant differences among individual trees were found in MC, BD, and CS. In addition, radial variations were almost constant from bark side to pith side. The results indicate that longitudinal E is independent from growth characteristics, and that the E. zwageri wood tested in this study has uniform BD and CS in the radial direction

那須山系におけるミヤマナラの更新様式

This study aimed to clarify clonal structure and reproductive modes, layering (asexual) and/or seedling regeneration (sexual), of Quercus crispula var. horikawae using eight nuclear EST-SSR markers; the species has stunt creeping multiple stems and occurs in pseudo-alpine zone of the mountains in the Sea of Japan side. This study was conducted in an isolated stand (alt. 1,570 m) of the species near Ohtoge-pass in Mts. Nasu, northern Tochigi Prefecture. DNA was extracted from leaves of 92 stems that did not have any distinct connection of roots and creeping stems above the ground. The results of DNA analysis indicated that the stand consisted of four genets (clones). Genet A, which had 87 stems (ramets), occupied throughout the study plot. The other clones (B, C and D), which were composed of 1-3 ramets, might be derived from seedling regeneration. In conclusion, reproductive modes in the stand were likely to be dominated by layering regeneration resulted from the creeping of stems rather than seedling regeneration that rarely occurred

北関東高原山系におけるフモトミズナラの種特性とミズナラおよびコナラの種特性との比較

We revised the taxonomic status of Quercus serrata subsp. mongolicoides (QSM) population occurring in hilly and lower mountainous regions of northern Kanto district. We conducted analysis of leaf morphology, genetic analysis and observation of leaf phenology for three congener species, QSM, Q. serrata (QS), and Q. mongolica var. grosseserrata (QMG). We set three sites, University forest at Funyu (S1), Kenminno-mori (S2) and Shojin-zawa (S3) in Mt. Takahara. Principal component analysis based on leaf morphological characters measured for the samples from the three sites showed that QSM and QMG apparently distinguished from QS. Genetic analysis including principal coordinates analysis, Bayesian clustering, and analysis of molecular variance using five loci of nuclear EST-SSR showed that QSM and QMG unambiguously distinguished from QS, but QSM and QMG were not discriminable from each other. Our observation of leaf phenology from the end of March to the middle of May in three years (2010-2012) in S1 and S2 indicated that QSM and QMG exhibited a similar pattern of the phenology and that their phenology progressed earlier than that observed in QS. Thus, we concluded that the QSM population in northern Kanto district should not be regarded as an intraspecific taxon of QS, but as intraspecific taxon of Q. mongolica, or intraspecific variation of QMG

Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models

Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and \u3e 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality. © 2006 Blackwell Publishing Ltd/CNRS

Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests

The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests

Broadening the Horizon of International Student Mobility Programme: Transformation of the EduTour Programme to Beyond Normal

The intense advancement in globalization in the past two decades has prompted the need for internationalization of higher education. Institutions of higher learning have realigned their approaches to include initiatives to develop their graduates’ global mindedness that would underpin their personal and professional lives. One of the strategies employed to meet this goal is through student mobility programmes which require experiences with host universities ranging from a few days to a year in length. This paper provides an illustration of the international student mobility programme called EduTour which is collaboratively designed by Universiti Malaysia Sarawak (UNIMAS) and Utsunomiya University Japan (UU), describes its journey from face-to-face to virtual, to the creation of intellectual property (IP) and commercialisation. In 2017, UNIMAS and UU signed the Memorandum of Understanding to strengthen their collaboration in teaching, learning and research. One of the initiatives is to establish student mobility programmes. After several rounds of discussion between UNIMAS and UU academics, the EduTour which is a two-week programme hosted by UNIMAS was planned and successfully implemented in 2018. Following its huge success, the programme continued in 2019 and 2020 with an increased number of participants and improvements made based on the feedback gathered from the participants. The EduTour includes English language classes based on Sustainable Development Goals (SDG) themes, campus tour, faculty visits, visits to historical sites and highlights of Kuching, recreational activities, food and cultural exchanges. Throughout the programme, UNIMAS participants take on the role of student buddies and provide a holistic support system that adds a special meaning to the programme. They are actively involved from welcoming the UU students and staff at the airport, as teaching assistants during the English classes, local guides during the visits, playmates during recreational activities, co-performers during the closing event, right up to bidding adieu at the airport. While the EduTour participants’ friendship continues beyond the programme through various social media platforms, it also became a catalyst for the students’ participation in other exchange programmes, internships, and scholarship opportunities. However, the EduTour’s continuity in 2021 was blurred by the travel restrictions imposed due to the COVID-19 pandemic. Nevertheless, motivated by requests from previous and potential participants and the valuable experiences gained from successfully carrying out the programme for three consecutive years, UNIMAS and UU decided to continue offering the programme despite all odds. UNIMAS and the UU coordinators discussed the possibility of conducting the EduTour virtually without compromising its quality. Decision was made to employ the hybrid approach with a combination of pre-recorded contents and live interactions that are similar to the old normal EduTour programme. The new beyond normal programme was aptly named e-EduTour and successfully carried out in February 2021. The uniqueness of the e-EduTour unfolded the opportunity for the creation of IP followed by the commercialisation of the programme. The presentation will discuss the full cycle of the student mobility programme from the improvements made based on the feedback gathered, to the application for IP and commercialisation of the beyond normal e-EduTour Module

Legacy Trees of Ernest Henry Wilson and John George Jack in Nikko, Japan

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