|Scientific Name:||Pterocarpus dalbergioides Roxb. ex DC.|
Lingoum dalbergioides (Roxb.) Pierre
Pterocarpus advenus Baill.
|Red List Category & Criteria:||Vulnerable A2d ver 3.1|
|Reviewer(s):||Deepu, S. & Oldfield, S.|
Pterocarpus dalbergioides is a large tree species endemic to the Andaman islands. The species bears cultural significance as it produces a valuable timber, it can be classed as one of the most decorative Indian timbers and is worth protecting and cultivating. Within some parts of the island the species is dominant and forms pure stands, or 'padouk' forests. The species is commonly present in the deciduous and semi-deciduous forest in almost all the Islands of Andaman. The species geographic range is relatively restricted. Assuming it is found across all the islands of the Andaman the species estimated extent of occurrence (EOO) is 14,679 km2.
It is estimated that over the past three generations the population has declined by at least 30% as a result of historical timber harvesting. Logging of the species is now more strictly controlled but the species habitat is becoming fragmented. The overall population size of the species is not known but it is considered to be in decline due to poor seed regeneration, with no saplings or seedlings being found across 106, 0.1 ha sites. The tree is long lived and thought to need forest disturbance for there to be significant regeneration. The species is assessed as Vulnerable.
|Previously published Red List assessments:|
|Range Description:||Pterocarpus dalbergioides is endemic to the Andaman Islands. It occurs in both southern and northern parts of the Andamans. There are no point data records for this species but assuming it occurs across all the islands that make up the Andamans south to Little Andaman islands the species has a potential estimated extent of occurrence (EOO) of 14,679 km2.|
The species is grown in some plantations in Malappuram and Wayanad Districts of Kerala, India but the total cultivated area is not anticipated to exceed 4 km2 (S. Deepu pers. comm. 2017).
Native:India (Andaman Is.)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||On the Andaman Islands Pterocarpus dalbergioides can be dominant or co-dominant sometimes forming pure stands of trees called 'padouk' forests. Otherwise it is scattered throughout deciduous or semi-evergreen across the islands. There are representatives of all diameter classes up to and over 180 cm dbh, however abundance within each category is not consistent. Higher girth classes were poorly represented although overall, they made up a larger proportion of the basal area of the forest due to their sheer size. Across 106, 0.1 ha plots in the Andaman Islands P. dalbergioides was found to have a population density of 34 stems/ha. However, across these field sites no seedlings or saplings were sited suggesting poor seed regeneration of the species (Prasad et al. 2008). The majority of trees were estimated to be between 43 and 77 years old, though a few individuals were found to be over 132 years old. One quarter of trees were found to be under 43 years old, but no trees were estimated to be below 10 years old. While surveying the trees Prasad et al. (2008) observed cutting of the trees, and cited the species to be threatened by illegal logging and forest fragmentation. This alongside the species predicted low regeneration suggests the species population is currently in decline. The population has also suffered major historical losses as result of the timber trade of this species. This is thought to have been motivated by the arrival of the East Indian Trading company over 200 years ago. Prior to this time the species was much more common than the present day with an annual availability of 5,000 to 6,000 tons of wood (Pearson and Brown 1932).|
It is estimated that over a period of 300 years there has been a definite decline in the number of reproductive mature individuals of at least 30%. Decline is predicted to continue into the future as there are very few seedlings and saplings remaining and few are predicted to reach maturity.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Pterocarpus dalbergioides is a large tree species, growing to over 18 m in height (Prasad et al. 2008). It occurs in decidous and semi-evergreen forests, where it can be dominant or co-dominant. It grows on well drained slopes and undulating terrain. The species that P. dalbergioides is associated with is dependent on the soil type but occurs in forests with Diospyros oocarpa, Celtis wightii, Agalia oligophylla, Dipterocarpus gracilis and Pterocymbium tinctorium. The species experiences poor, wild generation from seed. It is thought that the species only regenerates in forest gaps and following widespread forest disturbance. Pterocarpus dalbergioides is long lived and it is estimated that the species takes 10 years to reach 30 cm dbh (Prasad et al. 2008).|
|Generation Length (years):||100|
|Use and Trade:||This species is harvested for its valuable timber which is mostly exported to the Indian mainland. The species produces a prized redwood which is used for furniture making, joinery, inlay, flooring, tool handles, veneer, boat building and decorative features (Prasad et al. 2008). The chief use of the timber is for decorative purposes, such as panelling, parqueting, balustrades and cabinet work. Andaman Padauk has been proposed as a Rosewood substitute in musical instrument manufacture but is not yet used very extensively due to its colour. Compared to the more common African Padauk, which is listed on CITES, Andaman Padauk is considered to have a finer texture (Terence 2010 ). It was also used for billiard tables, interior work in first-class railway carriages and Pullman cars. The East Indian Railway used this timber for first- and second-class carriages and even an aircraft propeller was made of this timber (Pearson and Brown 1932). It is estimated that overall timber exports for the Andamans are 75,000 m3 (Sekhsaria 2001) but the volume contributed by P. dalbergioides is not known. Most harvest is from wild sources and the species is also thought to be subject to illegal logging. The species is also grown as a street tree in Africa and is known to be cultivated on the mainland of India too (Louppe et al. 2008).|
|Major Threat(s):||This species is threatened by illegal logging on the Andaman Islands (Prasad et al. 2008, Sekhsaria 2001). This is leading to population decline within the wild. The species also suffers from poor regeneration, reducing its capacity to bounce back after illicit cutting and putting the future viability of the species at risk. The species also has a small native range which puts it at greater risk from depletion. Its native forests are also becoming fragmented, generating further risk to the species (Prasad et al. 2008).|
This species is reported from at least half a dozen ex situ collections (BGCI PlantSearch 2017). It was previously assessed as Data Deficient on the IUCN Red List 1998. It is recommended that the remaining species habitat is protected or well managed to ensure the longevity of the species.
Trade of this species is presently highly restricted by different policies of the forest department of the Andaman & Nicobar administration and activities for its multiplication, reintroduction and conservation are occurring under various programmes. There are restrictions even for carrying the samples out of the Islands without prior permission from the Forest Department (S. Deepu pers. comm. 2017). They are also practicing selective felling and plan to restock the species in the wild (J. Alappatt pers. comm. 2017). This requires further investigation for the best germination and propagation practice for the species. Regeneration may require investigation as it is likely the species needs an open canopy to grow (S. Deepu pers. comm. 2017).
|Citation:||Barstow, M. 2018. Pterocarpus dalbergioides. The IUCN Red List of Threatened Species 2018: e.T33261A67802958.Downloaded on 22 September 2018.|
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