One of five threatened species of Podocarpus endemic to Madagascar where it is has a fragmented distribution due to grazing and habitat degredation.
Distribution
Endemic to northern Madagascar where all localities are in Antsiranana. Important sites are Mont Anjanaharibe, Mont Tsaratanana and Mont Marojezy. The estimated extent of occurrence is 16,866km² and the area of occupancy 150km² based on the distribution of herbarium specimens. There are five to seven locations and subpopulations are severely fragmented. There are no data indicating the size of subpopulations but there is no doubt that this is relatively small as the species is known from only a few disjunct localities. Dispersal is by birds, but little is known about distances and/or limits.
Habitat and Ecology
Podocarpus humbertii is reported from sub-humid forest, dry lowland deciduous forest, and ericoid thickets or wooded heath on mountain summits of gneiss and granite. The elevation ranges from altitudes of between 1600 to 2800m.
Human Uses
No economic uses have been recorded of this species. It is probably used for firewood locally.
Conservation Status
Global status
Endangered B2ab(ii,iii,v)
Global rationale
The area of occupancy (AOO) of this species is definitely below the threshold for Endangered (500km²) and may well now be less than here calculated due to continuing degradation of habitat, which occurs without as well as within protected areas due to grazing pressures. Although it is known from more than five locations, subpopulations are severely fragmented. This species therefore meets the criteria under B2 for Endangered.
Global threats]
This species is know from five to seven subpopulations (locations) and most of the herbarium collections were made between 1950-1960 with only one recent collection in 2001. Based on the mapped herbarium collections, the area of occupancy (AOO) is calculated as <150km², which falls within the threshold of Endangered (EN). Its habitat is (in part) dry lowland deciduous forest, which is under pressure from grazing. A continuing decline is inferred from the collection dates and the degradation of parts of its habitat. Only one collection, from Mont Tsaratanana, was made recently, in 2001.
Conservation Actions
This species has been collected in the following protected areas: Tsaratanana Reserve, Marojejy National Park and Anjanaharibe-Sud Special Reserve. Only one collection, from Mont Tsaratanana, was made recently, in 2001.
References and further reading
Farjon, A., Bachman, S., Gardner, M.F., Luscombe, D., Reynolds, C. and Thomas, P. (2006). Conservation Assessments of Data Deficient (DD) Conifers Using Herbarium and Geographical Information System (GIS) data. RBG Kew, Bedgebury Pinetum, RBGE, Edinburgh.
de Laubenfels, D.J. (1971). Deux nouveaux Podocarpus endémiques de Madagascar. Adansonia ser. 2 11(4): 713–715
de Laubenfels, D.J. (1972). Flore de Madagascar et des Comores. Gymnospermes - Cycadacees Podocarpacees. Museum National D'histoire Naturelle, Paris.
