Plant Functional Diversity Is Linked to Carbon Storage in Deciduous Dipterocarp Forest Edges in Northern Thailand

Studies of carbon storage using functional traits have shown that it is strongly affected by functional diversity. We explored the effects of functional diversity on carbon storage at the edge of a deciduous dipterocarp forest (DDF) ecosystem in Thailand. Aboveground biomass carbon (AGBC), soil organic carbon (SOC), and total ecosystem carbon (TEC) were used as indicators of carbon storage. Five functional traits were measured in 49 plant species to calculate the community-weighted mean (CWM) and Rao’s quadratic diversity (FQ). We assessed which functional diversity metrics best-explained carbon storage. The results indicated that AGBC had a significant, positive relationship with the FQ of wood density, and a negative relationship with the CWM of leaf thickness. SOC had a significant, negative association with the FQ of leaf thickness and a positive relationship with the CWM of specific leaf area (SLA). TEC was best predicted by increases in the FQ of wood density and the CWM of SLA. These findings indicate that CWM and FQ are important for understanding how plant traits influence carbon storage in DDF edge ecosystems and suggest that promoting a high diversity of species with dissimilar wood density and high SLA may increase carbon storage in chronically disturbed DDF ecosystems.

Diversity, traditional uses and conservation status of Zingiberaceae in Udorn Thani Province, Thailand

Saensouk P, Saensouk S. 2021. Diversity, traditional uses and conservation status of Zingiberaceae in Udorn Thani Province, Thailand. Biodiversitas 22: 3083-3097. Southeast Asia is recognized as the center of Zingiberaceae distribution with Thailand is among the important regions. Nonetheless, a comprehensive study in a regional context that investigates the biological aspects of the family is lacking. This study aimed to determine the diversity, distribution, ecology, conservation status, and traditional uses of the family Zingiberaceae in Udorn Thani Province, northeastern Thailand. In total, three tribes, nine genera, 47 species of Zingiberaceae were identified during a botanical survey between January and December 2020 in Udorn Thani. Curcuma and Kempferia were the most diverse genera with nine and eight species, respectively, followed by Zingiber as the third most diverse genus with seven species and Alpinia as the fourth most diverse genus with six species. While the genera Etlingera and Hedychium were the least diverse with each containing just one species. For all Zingiberaceae species, the flowering period was found between March and September, while the fruiting period was found between May and October. Zingiberaceae was found with the greatest frequency in five ecosystem types, namely cultivated areas, deciduous dipterocarp forest, mixed deciduous forest, dry evergreen forest and river basin. Twenty-one species were reported as rare species in research area, i.e. Boesenbergia baimaii, B. isanensis, Kaempferia picheansoonthonii, and K. udonensis. It was revealed that the traditional uses of many Zingiberaceae species from villagers in Udorn Thani Province were most frequently used for medicine, food, ornamentals, rituals, spices, perfume and cosmetics. Rhizomes, roots, pseudostems, young inflorescences, inflorescences, young leaves, leaves and fruits were the parts of this plant used.

Utilization of waterholes by globally threatened species in deciduous dipterocarp forest of the Eastern Plains Landscape of Cambodia

Deciduous dipterocarp forests throughout Asia provide crucial habitat for several globally threatened species. During the dry season water availability in these forests is primarily limited to perennial rivers and waterholes. Such water sources form an essential part of these dry forests and are used by multiple species, including large mammals and birds, but little is known regarding how waterhole characteristics affect wildlife use. We investigated waterhole utilization by six globally threatened dry forest specialists: banteng Bos javanicus, Eld's deer Rucervus eldii, giant ibis Thaumatibis gigantea, green peafowl Pavo muticus, lesser adjutant Leptoptilos javanicus and Asian woolly-necked stork Ciconia episcopus. We camera-trapped 54 waterholes in Srepok Wildlife Sanctuary, eastern Cambodia, during the dry season of December 2015–June 2016. We measured nine waterhole and landscape characteristics, including indicators of human disturbance. Waterhole depth (measured every 2 weeks) and the area of water at the start of the dry season were the main environmental factors influencing waterhole use. Additionally, waterholes further from villages were more frequently used than those nearer. Our study reaffirmed the importance of waterholes in supporting globally threatened species, especially large grazers, which are critical for maintaining these dry forest ecosystems. The results also suggested that artificially enlarging and deepening selected waterholes, particularly those further from human disturbance, could enhance available habitat for a range of species, including grazers. However, this would need to be conducted in coordination with patrolling activities to ensure waterholes are not targets for illegal hunting, which is a problem throughout South-east Asian protected areas.