Central Ayeyarwady Than-Dahat grassy forest

Description

This ecosystem is a grassy open woodland dominated by Tectona hamiltoniana (dahat) and Terminalia oliveri (than) that occurs throughout the rolling hills of the dry zone, corresponding to community types 1-7 of Oo and Koike (2015). The presence of dry clay soils is thought to be the key driver of its distribution (Davis, 1960). Trees in Than-Dahat grassy forests are rarely greater than 10 metres tall, and have a fairly sparse, open, distribution, as is characteristic of a savanna. A thick ground cover of grasses is present, and bamboo may occur (Oo and Koike, 2015). Mostly deciduous with C4 grassy groundcover (Ratnam et al., 2016). Two other isolated Than-Dahat ecosystems fringe the central dry zone in Myanmar.

Assessment summary

This ecosystem has a restricted range, and ongoing threats suggest that it is undergoing a continuing decline. The ecosystem is assessed as Vulnerable under Criterion B1. Further work is recommended to fill key knowledge gaps in biotic and abiotic degradation, as well as refining the distribution map for this ecosystem type.