Central Ayeyarwady floodplain grasslands

ဧရာဝတီအလယ်ပိုင်း ရေလွှမ်းလွင်ပြင် မြက်ခင်းတောများ

Extinction Risk

National IUCN statusCR

Climate and ecology




Palustrine Wetlands

Functional Group

Seasonal floodplain marshes


Central Ayeyarwady floodplain grasslands have been almost entirely converted to rice paddies. It formerly occurred over vast areas of the flat Ayeyarwady floodplain where it was seasonally inundated with monsoonal rain between about May and October. Now, extensive engineering of levee banks and drainage channels have dramatically altered the majority of this ecosystem type. Floodplain grasslands lack woody vegetation and are completely dominated by grasses that persist through dry periods, although in some areas may remain nearly permanently inundated depending on rainfall patterns. In its natural state, this ecosystem supports a very high abundance of waterbirds, including bitterns, herons, egrets, ibis.


Occurs across the majority of the mid- and elevated portions of the Ayeyarwady floodplain. Most have been converted to rice agriculture.


Native biota


Consists of mostly elephant grass Saccharum arundinaceum, (Kress et al., 2003), but also shorter grasses including Paspalum spp. and Cynodon dactylon (Poaceae). These seasonally wet grasslands support very high abundance and diversity of wetland bird species, including migratory birds, waterbirds and passerines such as Asian Golden Weaver Ploceus hypoxanthus (NT), Streaked Weaver Ploceus manyar and Red Avadavat Amandava amandava. Waterbird species in the wet season include Lesser Whistling Duck Dendrocygna javanica, Asian Openbill Anastomus oscitans, Little Cormorant Microcarbo niger, Yellow Bittern Ixobrychus sinansis, Cinnamon Bittern Ixobrychus cinnamomeus, Intermediate Egret Ardea intermedia, and Little Egret Egretta garzetta.

Abiotic environment

Mean temperature

No data


No data


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Flat areas of the Ayeyarwady floodplain, slightly more elevated than Ayeyarwady floodplain wetlands and sometimes on slightly sloping surfaces enabling slow drainage. Regular inundation during the monsoonal months of May to October, primarily fed by local rainfall and overbank river flows from upstream, but drying rapidly over the dry season.

Key processes and interactions

Regular inundation is the primary driver of ecosystem dynamics in this system. A regular influx of water, along with nutrients and aquatic species, supports an assemblage of predator species including migratory waterbirds. During dry periods, mobile fauna migrate to nearby floodplain wetlands that tend to hold water throughout the year.

Major threat

Major threat

Owing to frequent inundation by freshwater and occurring on flat landforms, the majority of this ecosystem is now converted to rice paddies. Invasion by exotic plants is promoted by eutrophication and soil disturbance. Increasing control of water flows throughout flat areas of Myanmar, including levees, dams and engineered river banks

Instruction: The visualization shows threats that are present within each ecosystem. According to IUCN, direct threats are the proximate human activities or processes that have impacted, are impacting, or may impact the the status of the taxon being assessed. Click of the highlighted icons to see details each threat category.

Ecosystem Assessment

Assessment Summary

Satellite derived data on the extent of seasonal surface water in the Ayeyarwady floodplain suggests that only 190 km2 of this ecosystem has not been converted to cropland. Assuming all seasonally inundated areas of the floodplain were once the Central Ayeyarwady floodplain grassland ecosystem, an estimate 92.4% of this ecosystem has now been converted to cropland. No data on other components of ecosystem degradation was available. Thus, the ecosystem is listed as Critically Endangered (A3).

Instruction: Click on the chart to view the detailed assessment result for each RLE risk criteria. Risk is defined as the probability of an adverse outcome over a specified time-frame. Here, the adverse outcome is the endpoint of ecosystem decline, which the RLE terms ecosystem collapse.

Ecosystem collapse definition

This ecosystem is considered collapsed when its area has declined to 0 km2, when regular inundation by freshwater ceases or all characteristic native biota (particularly plants) cease to occur.

Date Assessed


Year published


Assessed by

Nicholas Murray

Reviewed by

David Keith

Contributed by

Adam Duncan