Background: The stock dynamics of harvested wood products (HWPs) are a relevant component of anthropogenic carbon cycles. Generally, HWP stock increases are treated as carbon removals from the atmosphere, while stock decreases are considered emissions. Among the different approaches suggested by the Intergovernmental Panel on Climate Change (IPCC) for accounting HWPs in national greenhouse gas inventories, the production approach has been established as the common approach under the Kyoto Protocol and Paris Agreement. However, the 24th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change decided that alternative approaches can also be used. The IPCC has published guidelines for estimating HWP carbon stocks and default parameters for the various approaches in the 2006 Guidelines, 2013 Guidance, and 2019 Refinement. Although there are significant differences among the default methods in the three IPCC guidelines, no studies have systematically quantified or compared the results from the different guidelines on a global scale. This study quantifies the HWP stock dynamics and corresponding carbon removals/emissions under each approach based on the default methods presented in each guideline for 235 individual countries/regions. Results: We identified relatively good consistency in carbon stocks/removals between the stock-change and the atmospheric flow approaches at a global level. Under both approaches, the methodological and parameter updates in the 2019 Refinement (e.g., considered HWPs, starting year for carbon stocks, and conversion factors) resulted in one-third reduction in carbon removals compared to the 2006 Guidelines. The production approach leads to a systematic underestimation of global carbon stocks and removals because it confines accounting to products derived from domestic harvests and uses the share of domestic feedstock for accounting. The 2013 Guidance and the 2019 Refinement reduce the estimated global carbon removals under the production approach by 15% and 45% (2018), respectively, compared to the 2006 Guidelines. Conclusions: Gradual refinements in the IPCC default methods have a considerably higher impact on global estimates of HWP carbon stocks and removals than the differences in accounting approaches. The methodological improvements in the 2019 Refinement halve the global HWP carbon removals estimated in the former version, the 2006 Guidelines.

Background: Various plant odours have been shown to decrease heart rate and increase parasympathetic nervous activity. However, ‘innate’ autonomic responses without the influences of experience, assumptions, and prejudices of odours remains unclear. Aim: To clarify changes in heart rate and heart rate variability in infants while presenting different components of plant odours. Subjects and methods: The study participants included 17 infants aged 1–3.5 months. Each infant was exposed to the odours of α-pinene, D-limonene, and air (as a control) for two minutes after a two minute resting period without any odours. The intervals of heartbeat (R-R intervals) were recorded during this process. Results: Heart rate significantly decreased in response to the odour of limonene. Frequency analysis of heart rate variability revealed that the power value at 0.2 Hz was significantly higher during the odour presentation of limonene compared to the baseline, and that at 0.1 Hz and 0.4 Hz was significantly lower during α-pinene presentation. Conclusion: Autonomic responses to specific natural odours may be partly shaped innately, while underlying physiological mechanisms may be different between infants and adults.

This study investigated the effects of wood-derived visual and olfactory stimuli on subjective evaluations during work and rest. Twelve participants experienced seven conditions involving walnut panel interiors, Hinoki cypress scents, or their combination, introduced during either work or rest phases. A within-subjects design was used to assess spatial impressions, mood states, and fatigue. Visual stimuli significantly improved visual impressions across items such as “settling–unsettling” and “luxurious–simple” (p < 0.05). The Hinoki scent enhanced olfactory impressions and, when introduced during rest, reduced negative mood states including “Anger–Hostility” and “Confusion–Bewilderment” (p < 0.05). Combined stimuli further improved scent impressions (p < 0.1), suggesting cross-modal effects. However, their introduction during work increased “Anger–Hostility” (p < 0.05), highlighting the importance of context. Although the within-subjects design supports internal validity, the small sample size (n = 12) limits generalizability. These findings provide insight into the context-sensitive use of wood-derived sensory elements in workplace design.

This study mapped a wide range of naturally derived odors, including those derived from wood, on the two-dimensional axes of tense arousal (TA) and energetic arousal (EA), and examined whether quadrant differences influenced recovery following stress. In the context of Attention Restoration Theory and biophilic design, the study provided preliminary evidence that olfactory stimuli can be treated as a designable element in a functional and reproducible manner. In Experiment 1, wood flours, wood essential oils, and non-wood oils were mapped based on subjective ratings conducted under identical conditions, and differences in their TA–EA positions were revealed. Ratings of “naturalness” were associated with lower EA, suggesting that quadrant mapping can capture meaningful dimensions of odor perception. In Experiment 2, Hinoki and camphor were selected as contrasting stimuli. Hinoki facilitated initial recovery of autonomic nervous system activity, as shown by lower heart rate compared with no odor, whereas camphor showed no effect. These findings demonstrate that TA–EA quadrant mapping provides a practical framework for olfactory design in indoor environments.

This study aimed to explore the psychological effects of wooden frames and interiors in open-plan offices (OPO) and to understand the evaluation structure associated with wooden materials. A combination of quantitative subjective evaluations and qualitative interviews was conducted, utilizing the Evaluation Grid Method (EGM) to understand participants’ evaluation structure and criteria for wooden OPO. The study involved 20 Japanese participants who evaluated 16 computer-generated images of OPO, designed with varying factors related to wood placement, material, and spatial elements. Findings revealed that OPO utilizing wooden columns and beams significantly enhances users’ willingness to use the office compared to those without. Notably, the combination of wood’s placement and other spatial elements is critical rather than the mere quantity of wood. Furthermore, the study reveals that factors such as age and gender affect the willingness to use OPO suggesting that different user attributes may lead to varying perceptions of comfort and privacy. The results indicated that while the evaluation criteria for assessing spaces were generally shared across participants, the relative importance of specific items varied depending on user attributes. This study offers valuable insights into the complex evaluation structures related to wooden office spaces, contributing to the growing field of research on wooden interiors.

In recent years, wooden construction and interior materials in the nonresidential sector have attracted attention for their potential to reduce environmental impacts and improve occupant performance. Previous studies have provided foundational knowledge on the effects of wooden spaces on humans. However, in nonresidential buildings, it is essential to investigate the effects of wooden spaces on humans based on building type, as the performance requirements of each building differ from those of residential buildings. Since school buildings symbolize the community and represent a space, where students spend most of their time, this study investigated the actual environment of school buildings. The purpose of this study was to investigate the actual conditions of students enrolled in wooden and non-wooden classrooms and to consider the advantages of wooden classrooms in real environments. Environmental measurements and surveys on psychological, physiological, and student activity were conducted for 5 days with 144 second-year students at a junior high school in Japan, in both wooden and non-wooden classrooms. Environmental measurements included illuminance, spectral irradiance, temperature, humidity, and atmospheric pressure. Students’ psychological evaluations (concentration, fatigue, comfort, coziness, blackboard visibility, sleepiness, and thermal sensation) were conducted on a 7-point or 9-point scale. In addition, responses regarding mood states to the Profile of Mood States, 2nd Edition, were gathered. Physiological parameters such as pulse rate and blood pressure were measured over time. Activities such as steps and acceleration were measured. The measurements showed that although students in wooden classrooms were less aroused, they scored more positively than those in non-wooden classrooms for most other subjective evaluation items. Students in wooden classrooms had lower negative mood states than those in non-wooden classrooms. No statistically significant physiological differences were identified between students in both interior types. Therefore, this study provides a case study on the positive impact of wooden interiors in junior high schools, particularly on students’ subjective evaluations and mood states.