Cunninghamia konishii Hayata is a rare and endangered plant species that plays a relevant role in ecological andcommercial systems of natural forests in Vietnam. In this research, we evaluated the potential geographic distribution ofC. konishii under current and future climatic conditions in Northern Vietnam using the ecological niche modelling approachbased on the largest available database of occurrence records for this species. C. konishii is mainly distributed inthe northern part of Vietnam at altitudes above 1000 m where the slopes range between 12 and 25 degrees, particularlyin special-use and protected forest. The optimal distribution area of C. konishii requires specific climatic conditions: anannual precipitation around 1200 mm, precipitation of the warmest quarter ranging from 600 to 800 mm, a precipitationseasonality of 90 to100 mm, an annual mean temperature ranging from 12°C to 19°C, and a temperature seasonalityranging from 300 to 350. Additionally, the species requires specific soil groups: humic acrisols, ferralic acrisols, andyellow-red humic soils. Considering these requirements, the results of our research show that the suitable regions for thegrowth of C. konishii are found in the provinces of Ha Giang, Son La, Thanh Hoa and Nghe An, covering a total area of1509.56 km2. However, analyzing the results under the Community Climate System Model version 4 (CCSM4) model, itis possible to observe that the area will decline to 504.39 km2 by 2090 according to RCP 2.6 scenario, to 406.25 km2 inthe RCP 4.5 scenario, and to 47.62 km2 in the RCP 8.5 scenario. The findings of this present research may be applied toseveral additional studies such as identifying current and future locations to establish conservation areas for C. konishii.

Tree species inventories, particularly of poorly known dry forests, are necessary to protect and restore them in degraded landscapes. The present research has been conducted to compare taxonomic diversity and community composition in four dry forests (DF) categories with different standing volume levels: very low (DFV), low (DFP), medium (DFM) and high (DFR). This quantitative assessment of taxonomic diversity, forest structure and species composition were obtained from 103 sample plots (0.1 ha each). The regeneration potential of trees was assessed in 515 subplots (4 m × 4 m) located within the 103 plots. A total of 1,072 trees representing 87 species belonging to 37 families were recorded in 10.3 ha of total sampled area. The ranges of diversity indices observed in the four forest types were: Margalef's (5.44–8.43), Shannon-Wiener (1.80–2.29), Simpson diversity (0.76–0.87) and evenness (0.32–0.35). The regeneration potential of rare and threatened species Dalbergia oliveri, Hopea recopei, Dalbergia bariensis, Sindora siamensis, Parashorea stellata was observed to be poor. Conversely, Cratoxylon formosum, Shorea obtusa, Dipterocarpus tuberculatus, Dipterocarpus obtusifolius, Terminalia alata, Shorea siamensis and Xylia xylocarpa were the most dominant species at the seedling and sapling stage, showing a strong potential for regeneration. Overall, this study provides useful information on tree species diversity and composition for tropical dry forests which can be used as baseline data to develop incoming plans for forest management and conservation in Vietnam's Central Highlands Region.