Bulbophyllum argoxanthum

The drivers of forest change in Papua New Guinea's forests were identified as subsistence agriculture, logging, forest fires, clearance for plantations and mine-related forest clearance (Shearman et al. 2008). The locality of collection appears, from satellite imagery, to have continuous forest at higher altitudes, although the valley has some small settlements, an airstrip and small scale agricultural activity and the vegetation here appears to be largely grassland. No specific information was available, for the known site of collection for this orchid, in relation to threat of fire, however, the likelihood of fire increases particularly in dry years and droughts associated with El Niño events. Impacts are becoming more frequent and severe and the area of Papua New Guinea's montane forests has been significantly reduced through burning (Shearman et al. 2008). Although forests may recover, in high altitude valleys there is evidence of trees being killed by fire spreading up from grasslands in the valley bottoms, which may result in permanent conversion of forest to grasslands (Filer et al. 2009) and there is a low frequency and diversity of epiphytic plants in many forests known to have been burned (Johns 1989). The impact of drought itself may also cause decline in orchid populations (E. De Vogel pers. comm. 2017). Analysis of forest loss, with more than 30% canopy density, suggests a loss of c. 400 ha in the nearby 17,760 ha mountain area between 2001 and 2015 (Global Forest Watch 2017) although the causes are not specified. A gain of 97 ha is also estimated in this area between 2001-2012, which may represent recovery, for example after logging. The Tolukuma gold mines lie just to the east and online images suggests local impacts on the montane forests here. There are logging concessions within 40 km of the area and an area demarcated for future mineral exploration to the north. Species of the genus Bulbophyllum can be in demand for cultivation and may be targeted by orchid collectors, particularly as improvements in air transport have allowed other orchids from remote areas, such as the Highlands of New Guinea, to reach nurseries, for example in the U.S.A. within a few days of their collection from the wild (Cribb 1983) and collection from the wild is a potential threat to this species.

The area where this orchid was collected has no protected status and there are no nearby protected areas. Protected area status would be beneficial to conserve the montane forest habitat from any ongoing and future threats. There are no ex situ sites recorded (BGCI 2017), but this species was grown in cultivation in Leiden Botanic Garden in 2003 (de Vogel et al. 2017). Surveys and further research are needed to provide information about the current distribution, population and habitat status for this species. Further studies are needed to understand its life history, ecology and any specific threats, in order to determine if any targeted conservation measures or monitoring are required.