Native biota include invertebrates, fungi, bacteria and some vertebrates, notably bats. One hundred and thirteen species of bat have been recorded in Myanmar, including recently discovered endemics such as the Kachin Woolly Bat (Kerivoula kachinensis; Bates et al, 2004; Darwin Initiative, 2005, Francis, 2019). There is a single near- endemic bird, Greyish Limestone-babbler Turdinus crispifrons restricted to karst in Myanmar and neighboring Thailand. Most biota are well-adapted to light scarcity, including reduced eyes, pigmentation and wings, and specialised non- visual sensory organs (Keith et al., 2019). Beyond bats, no publications were found to further identify the characteristic biota of karst caves in Myanmar.
Aerobic Karst caves
အောက်စီဂျက်ရနိုင်သော ထုံးကျောက် လှိုဏ်ဂူများ
Extinction Risk
NE
DD
National IUCN statusLC
NT
VU
EN
CR
CO
Climate and ecology
RealmSubterranean
BiomeDry Subterranean
Functional GroupSubterranean lithic systems
Description
Aerobic karst caves are dark subterranean limestone caves that are air-filled and support simple, low productivity ecosystems (Keith et al., 2019). Owing to light limitation, there is a distinct lack of photosynthetic primary producers and herbivores, and Karst cave biota is therefore typically dominated by detritivores and a few predators. In Myanmar Karst caves are widespread (Waltham and Eavis, 2004). Subterranean streams and pools also occur within Karst voids. These are transitional subterranean freshwater ecosystems that are distinct from the aerobic ecosystems with which they co-occur, and outside the scope of this assessment. High degrees of endemism within, and diversity among isolated karstic hills, caves, and towers result from a multitude of ecological niches afforded by their complex terrain along with their highly fragmented habitat-island nature. The high levels of biodiversity and site-specific endemism in karst habitats rival those of most other habitats throughout the tropics, yet karstic regions are rapidly becoming some of the most imperilled ecosystems on the planet (Clements et al., 2006). Southeast Asia harbors more karst habitat than anywhere else on earth (Day and Ulrich, 2000) but unregulated and unsustainable quarrying practices continue to threaten their integrity and are the primary threat to the survival of karst-associated species.
Distribution
An estimated 80,000 km2 of Myanmar consists of Karst environments (Day and Urich, 2000). A recent assessment of bat caves recorded 66 bat caves distributed across Myanmar, which is the best available indicative of the distribution of karst cave ecosystems in Myanmar, but likely underestimates the total number of Karst caves by a substantial margin. The distribution of karst caves follows the distribution of karst, which is primarily located in the Shan plateau, Kayin State, Mon State and Taninthyari Region.
Characteristic
Native biota
Details
Abiotic environment
Mean temperature
No data
Soil
No data
Precipitation
No data
Elevation
No data
Details
Karst caves form in rocky karst environments from the chemical weathering of limestone by surface water or by phreatic sources (Keith et al., 2019). They are characterised by lack of light, except at their openings, and low variability in temperature and humidity.
Key processes and interactions
The availability of light and nutrients is a key ecological driver in cave ecosystems. Energy and nutrients are imported from seepage, tree roots, bats and birds, supporting a biota consisting mainly of detritovores and predators. Karst caves are normally insular in distribution with poor connectivity, and therefore frequently have very high levels of local endemism.
Major threat
Major threat
Bird nests from karst caves in the Myeik Archipelago are harvested and sold for human consumption (Dreybrodt, 2019). In Thailand and Indonesia, bats are hunted for human consumption, although the extent of this practice in Myanmar is unknown (Clements et al 2006). Cement production is a threat to karst landscapes (Clements et al 2006), and quarrying may threaten caves in nearby areas.
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
Although restricted across Myanmar, inferred threatening processes are unlikely to cause continuing declines of a non-negligible magnitude in extent. Limestone quarrying is a highly localised threat that warrants ongoing monitoring in this regard. Least Concern.
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
Karst caves are considered collapsed when their total volume reduces to 0 m3 through a process of collapse or weathering. In addition, karst cave ecosystems have collapsed if sufficient light is available at all parts in the cave system to limit the persistence of characteristic cave dwelling organisms.
Date Assessed
2019-08-07
Year published
2019
Assessed by
Nicholas Murray
Reviewed by
David Keith
Contributed by
Robert Tizard
references
references
Resources
ecosytems-MM view.csv
Myanmar Translation
