 | This article relies largely or entirely on a single source. (January 2023) |
Pachypodium habitats consist of isolated, specialized, micro–environmental niches, generally xeric, rocky, frost-free areas within parts of western Madagascar and southern Africa. Pachypodium species are often indifferent to the regional ecological, biotic zone of vegetation, a fact which explains some of Pachypodium morphology and architecture. The large scale vegetation zones are in some cases irrelevant to the micro-environments of Pachypodium, in the sense that the xeric niches may be embedded in larger mesic biomes.
Most Pachypodium are rupicolous species occur on rocky outcrops, steep hills, and on inselbergs or kopjes, land or rocky masses which have resisted erosion and stand isolated in level or gently sloping terrain, sometimes above a forest canopy. Rocky outcrops, steep hills, and inselbergs create microclimate conditions that may be different from the general climate of a region.
The habitats of Pachypodium are thought of as arid ecological, even when they occur in pre-humid zonobiomes, because the taxon's topographic position and microclimate conditions differ significantly from the context of the greater ecological conditions within the landscape. The pre-humid zonobiomes are humid zones of regional biotic community characterized chiefly by the dominant forms of plant life and prevailing climate, such as forests or mountains. On these ecological islands the flora significantly differs from the greater surrounding zones of vegetation, where a smaller immediate area under the influence of a micro-environmental condition is defined. In larger areas of vegetation, the isolation of these plants in these "arid islands" become very conspicuous during prolonged periods without rain.