Search Results (3)

This study investigates the Fukugi (Garcinia subelliptica) windbreak landscapes on Iriomote Island through case studies in two of its oldest villages, Sonai and Hoshitate. These windbreak forests, integral to the cultural landscape of Okinawa, offer both ecological and socio-economic benefits. Using field measurements and surveys, the research analyzes the distribution, growth patterns, and historical significance of Fukugi groves within the village setting and compares naturally regenerated forests with those planted by humans. The findings underscore the importance of Fukugi trees in promoting sustainable rural landscapes, where they dominate the local ecosystem of rural settlements. Fukugi windbreak landscapes in Okinawa are characterized by trees encircling homes on all four sides, distinguishing them from homestead windbreaks found in other regions of Japan. Surveys from the two villages suggest that the original homestead windbreak forests in the Yaeyama region contain a diverse mix of tree species, with Fukugi and Calophyllum inophyllum being predominant, along with other useful species like Diospyros ferrea and Podocarpus macrophyllus. These species were selected not only for their windbreak capabilities but also for timber and home furniture production. The study’s findings on naturally regenerated Fukugi groups support the hypothesis that the cultivation of Fukugi as a windbreak species originated in the Yaeyama region and likely spread to other parts of Okinawa, influencing both the ecological and cultural evolution of the region’s landscapes. Full article

Cytotoxicity and apoptosis-inducing properties of compounds isolated from Garcinia subelliptica leaves were investigated. The hexane-soluble portion of MeOH extracts of G. subelliptica leaves that showed cytotoxic activity was separated to yield seven compounds 1–7. Chemical structure analysis using NMR spectroscopy and mass spectrometry confirmed that compound 1 was canophyllol, and compounds 2–7 were garcinielliptones N, O, J, G, F, and garcinielliptin oxide, respectively. Among them, garcinielliptone G (5) showed growth inhibition by causing apoptosis in THP-1 and Jurkat cells derived from human acute monocytic leukemia and T lymphocyte cells, respectively. Apoptosis induced by garcinielliptone G (5) was demonstrated by the detection of early apoptotic cells with fluorescein-labeled Annexin V and increases in cleaved caspase-3 and cleaved PARP protein levels. However, the addition of caspase inhibitor Z-VAD-FMK did not affect growth arrest or apoptosis induction. These results suggest that garcinielliptone G (5) can induce both caspase-3 activation and caspase-independent apoptosis. Therefore, garcinielliptone G (5) may be a potential candidate for acute leukemia treatment. Full article

Research Highlights: This study contributes to the improvement of the understanding of ecosystem functions of trees growing outside the forest, by quantifying the carbon sequestration function of a homestead windbreak, for example, a linear forest belt planted bordering a farmhouse in small islands. Background and objectives: Carbon storage in small-scale stands of forests have been less studied compared to that in large-scale forests. The aims of the present study were to clarify the ecological functions of carbon storage and the economic value of homestead windbreaks to propose effective conservation strategies for old-growth homestead windbreaks in the face of climate change. Materials and Methods: On the small islands of Okinawa Prefecture, the dominant tree species used for the homestead windbreaks is fukugi (Garcinia subelliptica Merr.). We collected data on the diameter at breast height (DBH) and the height of 23,518 fukugi trees in 10 villages from 2009 to 2018. Results: The total amount of carbon stored in the remnant fukugi homestead trees of the 10 surveyed hamlets was 6089 t-CO₂. The amount is equivalent to the carbon amount that is stored in a 40-year-old Japanese cedar (Cryptomeria japonica) forest, a representative tree species in Japan, of 20.9 ha area. Furthermore, the estimated economic value of the homestead trees was equivalent to USD 235,433, in terms of the plantation and management costs of 40-year-old Japanese cedar forests. This study revealed that homestead trees planted in an orderly line usually have a high density; hence, they have a high potential for biomass accumulation, carbon sequestration, and climate change mitigation. Moreover, homestead trees could contribute to a reduction in carbon diffusion, by cooling the house and reducing potential energy consumption. The findings related to homestead trees are consistent with those of other types of trees outside forests or small patches of trees: not adding to future land use competition and highly effective at carbon sequestration. Conclusions: The finding related to the carbon storage of homestead trees will provide basic information, as well as a new perspective on future local conservation and its contribution to climate change mitigation. This study suggests the necessity of the existing trees being properly managed, recruiting trees to be planted to replace old-growth trees, and replanting trees near newly established houses or old homesteads where trees have been cut. Full article