Resident aquatic species are adapted to drying and wetting, enabling them to persist through extended dry periods. Grasses dominate including Phragmtes australis, other canegrasses, Leersia and Cynodon dactylon. Aquatic herbs such as Persicaria and Ludwigia are common. Ottelia alismoides is abundant in most permanent and seasonal wetland ecosystems across the Ayeyarwady floodplain (Kress et al., 2003). There is a very high abundance and diversity of wetland bird species, including migratory birds, waterbirds and specialist passerines such as Jerdon's Babbler Chrysomma altirostre (VU), Asian Golden Weaver Ploceus hypoxanthus (NT), Streaked Weaver Ploceus manyar, and Yellow-throated Bunting Emberiza elegans (CR). Waterbird species include Lesser Whistling-duck Dendrocygna javanica, Cotton Pygmy-goose Nettapus coromandelianus, Little Grebe Tachybaptus ruficollis, Purple Swamphen Porphyrio porphyrio, Asian Openbill Anastomus oscitans, Glossy Ibis Plegadis falcinellus, Little Cormorant Microcarbo niger, Oriental Darter Anhinga melanogaster (NT), Pheasant-tailed Jacana Hydrophasianus chirurgus, Bronze- winged Jacana Metopidius indicus and Black- winged Kite Elanus caeruleus. There is also a very broad range of Herons (Ardeidae), Sandpipers, Snipes and Phalaropes (Scolopacidae). This ecosystem also supports an important population of Fishing Cat Prionailurus viverrinus (VU).
Ayeyarwady floodplain wetlands
ဧရာဝတီ ရေလွှမ်းလွင်ပြင် ရေဝပ်ဒေသများ
Extinction Risk
Climate and ecology
RealmFreshwater/Terrestrial
BiomePalustrine Wetlands
Functional GroupSeasonal floodplain marshes
Description
Ayeyarwady floodplain wetlands are shallow, often small, lakes that occur across the Ayeyarwady floodplain. They can be fully vegetated with non-woody vegetation or occur as patches of open water, and undergo regular seasonal drying and filling with monsoonal rain. Generally, they maintain some permanent water in at least part of their distribution throughout the year in most years.
Scattered across the Ayeyarwady floodplain.
Native biota
Abiotic environment
Mean temperature
No data
Soil
No data
Precipitation
No data
Elevation
No data
This ecosystem occurs as small wetland lakes in shallow depressions and catchments across the flat, sandy Ayeyarwady floodplain. During the monsoon, from May to October, these lakes fill with direct rainfall and from upstream and overbank flows, often increasing the size of open water patches by an order of magnitude. The pronounced dry season, lasting up to 6 months causes significant drying, with deeper wetlands acting as dry season refuge for a wide range of native fauna.
Key processes and interactions
Filling and drying between wet and dry seasons drive a highly variable ecosystem, with considerable variability in water quality, temperature, dissolved oxygen and nutrients. Depth is shallow (generally <2 m). Some wetlands may retain standing water year- round, within minimal depth in the dry season. They are often isolated for long periods of each year, and may be considerable variability between individual lakes across the distribution of this ecosystem.
Major threat
Conversion to rice paddies and aquaculture, and water extraction threaten this ecosystem throughout its range. Engineered drainage channels are also a key threat, diverting seasonal waterflows away from the wetlands.
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.
Assessment Summary
This ecosystem is widespread with EOO and AOO not meeting category thresholds for threatened. However, an assessment of present distribution (~2016) against an assumed historical distribution that approximates the same distribution as rice- paddies today, suggests that at least 70.1% of this ecosystem has been transformed to agriculture since the 1750s. The ecosystem therefore qualifies as Endangered under Criterion 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
2019-09-21
Year published
2019
Assessed by
Nicholas Murray
Reviewed by
David Keith
Contributed by
Adam Duncan
references
Resources
ecosytems-MM view.csv
Myanmar Translation
