Adaptation strategies for rainfed rice water management under climate change in Songkhram River Basin, Thailand

This study investigates the potential impacts of climate change on water resources and evaluates adaptation strategies on rainfed rice water management under climate change scenarios in the Songkhram River Basin, Thailand. The Soil and Water Assessment Tool (SWAT) model was used to project the future water availability under climate change scenarios for the period of 2020–2044. Future annual water availability is expected to remain unchanged due to unchanged future rainfall but expected to reduce from June to November due to changes in seasonal rainfall. The effects of supplying irrigation water to reduce the impact of climate change and increase rainfed rice production were evaluated. To increase the rice production by 15%, it is proposed to construct a reservoir with a capacity of below 65 MCM in each of the 15 sub-basins to fulfill the irrigation water requirements during the rainfed rice season. Alternatively, adaptation at the farm scale can be implemented by constructing ponds with a capacity of 900 m3 to store water for 1 ha of rice field to meet the potential rice yield during the non-rainfed rice season. The results of this study are helpful to policymakers in understanding the potential impacts of climate change and the formulation of adaptation strategies for water and rice sectors in the basin.

Molecular assessment and transcriptome profiling of wild fish populations of Oryzias mekongensis and O. songkhramensis (Adrianichthyidae: Beloniformes) from Thailand

Among the fish of the genus Oryzias, two species are frequently used as model animals in biological research. In Thailand, Oryzias mekongensis is usually found in natural freshwater near the Mekong Basin in the northeast region, while O. songkhramensis inhabits the Songkhram Basin. For differential morphological identification, the coloured bands on the dorsal and ventral margins of the caudal fin are used to distinguish O. mekongensis from O. songkhramensis. However, these characteristics are insufficient to justify species differentiation, and little molecular evidence is available to supplement them. This study aimed to investigate the molecular population and transcriptome profiles of adult O. mekongensis and O. songkhramensis. In the molecular tree based on cytochrome b sequences, O. mekongensis exhibited four clades that were clearly distinguished from O. songkhramensis. Clade 1 of the O. mekongensis population was close to the Mekong River and lived in the eastern portion of the upper northeast region. Clade 2 was far from the Mekong River and inhabited the middle region of the Songkhram River. Clade 3 was positioned to the west of the Songkhram River, and clade 4 was to the south of the Songkhram River Basin. After RNA sequencing using an Illumina HiSeq 2500 platform, the gene category annotations hardly differentiated the species and were discussed in the text. Based on the present findings, population dispersal of these Oryzias species might be associated with geographic variations of the upper northeast region. Molecular genetics and transcriptome profiling might advance our understanding of the evolution of teleost fish.

Influence of Indigenous Spiritual Beliefs on Natural Resource Management and Ecological Conservation in Thailand

Understanding how indigenous people manage their natural resources can provide a basis for formulating appropriate policies for natural resources management that benefits them while preserving their cultural beliefs. The objective of this study is to investigate the factors that influence the management of natural resources and the conservation of river ecology by the indigenous people in the Nongchaiwan wetland. We conducted in-depth interviews with 5 key informants and quantitative surveys with 158 households in two phases over a period of 3 years. Ancestral spiritual beliefs that are still salient in the Lower Songkhram River Basin influence natural resources management because they traditionally link people and natural resources. Such spiritual beliefs in the Lower Songkhram River Basin supported the indigenous people to continue conserving the natural resources in their territory. In addition, property rights granted to indigenous people also contribute to the conservation of natural resources. Our findings suggest that policy makers should engage with local beliefs in order to achieve sustainable resource management and, therefore, such practices should be recognized and included in the government’s policies on natural resources management in locations, where indigenous people live for generations.