Kachin warm temperate rainforest

Description

Kachin Warm Temperate Rain Forest occurs between c. 1,500 – 2,000 m in montane areas with distinct winter and spring seasons with little snow in winter. What makes this altitudinal zone special is the unique mix of taxa that are typically considered “tropical” with those that are considered “temperate” growing together. Kingdon-Ward (1945) noted that in this zone the temperate rain forest is probably richer in species than any other zone of equal depth in northern Myanmar. Many trees regarded as properly belonging to the “subtropical hill jungle” actually extend far into the temperate zone, and, it is impossible to draw a hard and fast line between the two. A subtler transition is also in effect, where different species in the same genus (e.g. Rhododendron, Symplocos or Magnolia) phase in and out as altitude increases. The upper canopy of this forest attains heights of 30 to 40 m and is heavily burdened with epiphytes. Many of them are shrubs and small trees (Agapetes, Rhododendron, Sorbus medogensis, Aralia leschenaultii, orchids and ferns). The burden of epiphytes and occasional gales cause tree limbs to break, opening the shade of the crown cover and giving way to new forest successions, often with bamboo.

This forest type is similar to the Kachin hills subtropical rain forest, however, there is not a distinct boundary between the two zones. According to Kingdon-Ward (1944), the lower and upper limits of Exbucklandia populnea mark this ecosystem.

Assessment summary

This ecosystem is broadly distributed and relatively free from human impact throughout its range except for a few pockets. Some climate simulations suggested environmental conditions may reduce over the next three decades sufficiently to meet Vulnerable category thresholds, but the majority of model runs suggested that this will not occur on a scale or severity suitable to result in listing within a threatened category. However, a post-assessment expert review suggested this ecosystem could meet threatened category thresholds if further data were available on reductions in geographic distributions and ecosystem degradation. Therefore, the ecosystem is assessed as Data Deficient and we recommend urgent further work to address this knowledge gap to enable a complete assessment of this ecosystem type Data Deficient.