Bulbophyllum pachypus, an epiphyte endemic to Madagascar, occurs in humid and subhumid forests of CE, E, NW and SE of Madagascar, at elevation of c. 607–1,770 m.

The species is recorded from 77 collections made between 1925 (Perrier de la Bâthie 17121) and 2020 (Ambatovy Spirit Collection 4062A5612/2). Twenty-nine collections representing 21 occurrences have been recorded within 11 protected areas. In addition to these legally protected sites, three collections representing three occurrences have been made in the conservation zone surrounding the footprint of a mining project in Madagascar, which would be subject to protection in the near future. Forty collections representing 19 occurrences have been made in the Ambatovy footprint of a mining project undergoing intense human pressure such as forest clearing. This occurrences should be considered as extirpated due to the forest clearing by mining project activities. It is also known from five collections representing four occurrences have been located in unprotected forest subjected to selective logging, timber harvesting for small-scale subsistence and slash-and-burn practices (tavy) and fire for grazing. The species is thus known from 77 collections representing 19 extirpated occurrences, 28 existing occurrences and 16 subpopulations.

The extent of occurrence (EOO) of B. pachypus is estimated to be 41,617 km² (far exceeding the limits for Vulnerable status under criterion B1) whereas its area of occupancy (AOO) is estimated at 96 km² (which falls within the limits for Endangered status under criterion B2). These 28 remaining occurrences represent a total of 16 locations (sensu IUCN 2022) with respect to the most serious plausible threat, slash-and-burn agricultural practice (tavy), exceeding the upper limit for Vulnerable status. We estimate that the past loss of its habitat, which will continue, has and will induce a strong continuous decline in habitat quality, number of subpopulations, and mature individuals in the next ten years as well as an important decline in its EOO and AOO. We also suspect an ongoing population reduction (number of subpopulations) of 49 % (23 of the 47 occurrences), the ones occurring in Moramanga and surrounding, Anosibe An’Ala for this species over 30 years period (three generations) in the past and the future, where the causes of reduction, forest clearing, will not cease and may not be reversible based on a decline in extent of occurrence, area of occupancy and habitat quality falling within the threshold for Endangered status. Since the threat level is higher under criterion A than criterion B, based on IUCN guidelines, the first applies. Bulbophyllum pachypus is thus assigned a Vulnerable status; VU A4(c).

Bulbophyllum pachypus is an epiphyte endemic to Madagascar, seven Regions: Alaotra-Mangoro (Ambatovy, Anosibe an'Ala, Ambatofotsy, Lakato, Andasibe, Analamazaotra, Maromizaha) and Atsinanana (Vohibe-Ambalabe) in the formerly recognized Toamasina Province; Analamanga (Anjozorobe, Amparafaratany) in the formerly recognized Antananarivo Province; Sava (Marojejy) in the formerly recognized Antsiranana Province; Sofia (Anjiabe, Andranomena) in the formerly recognized Mahajanga Province; Ihorombe (Andringitra), Vatovavy (Ranomafana) in the formerly recognized Fianarantsoa Province and Sofia (Bealanana) in the formerly recognized Mahajanga Province in humid and subhumid forests (Madagascar Catalogue 2022).

Bulbophyllum pachypus is currently thought to be stable even though some habitats of the species habitat are threatened. The number of mature individuals of B. pachypus is not known and further research is needed to gather population data.

Bulbophyllum pachypus is an epiphytic herb, occurring in subhumid and humid, evergreen forests between 607 and 1,770 m elevation.

This species experiences a continuing decline in EOO, AOO, and habitat quality due to shifting cultivation and mining. Nineteen subpopulations of this species have been recorded on the footprint of a mining project undergoing intense human pressure such as forest clearing. Four subpopulations are known from unprotected forests subjected to selective logging, timber harvesting for small-scale subsistence, slash-and-burn agricultural practices (tavy), and fire for grazing.

There are no reported uses of this species, but it may be sought after by specialist collectors.

Twenty-nine collections (21 occurrences) have been recorded in 11 protected areas, the Analamazaotra National Park (two occurrences), the Andringitra National Park (one occurrence), the Makira Natural Park (two occurrences), the Protected Harmonious Landscape of the Anjozorobe-Angavo Complex (two occurrences), the Ambatofotsy Protected Harmonious Landscape (four occurrences), the Ranomafana National Park (one occurrence), the CAZ (Natural Resources Reserve of the Ankeniheny Zahamena Corridor) (four occurrences), the Marojejy National Park (one occurrence), the Maromizaha Protected Area (one occurrence), the CAZ - Vohibe Forest (Natural Resources Reserve of the Ankeniheny Zahamena Corridor) (one occurrence), and the Torotorofotsy Protected Area (two occurrences). The species is included in Appendix II of CITES. Three collections have been made in the conservation zone surrounding the Ambatovy mining project. It has been also brought to cultivation at Ambatovy, Ambalabe, and Antananarivo shade houses.