Diversity of Upper Katanga epiphytes (mainly orchids) and distribution in different vegetation units

Vascular epiphytism in Upper Katanga is approached for the first time. It concerns holoepiphytes and occasional epiphytes but not lianas. Some 127 taxa were encountered. Orchidaceae takes the top position with 79 species. Their distribution regarding the five main woody vegetation units (open forest or woodland, dry evergreen forest, gallery forest, mountain forest, swampy forest) has been recorded by a weekly survey made during twenty years. Regarding diversity, gallery forests take the pole position with 14 taxa restricted to this unit as well as 50 other taxa occurring in other units as well. This is tremendous, notably according to the heavy anthropogenic pressure on this ecosystem, of which the expanse is continuously reduced and which covers far below 1% of the country. Open forests or woodlands, mainly of wetter miombo type, occur in second position with respectively 7 and 48 taxa. Other main vegetation units take a tiny part regarding epiphytic orchid biodiversity. With 36 taxa, pteridophyte diversity is in second position, as in African rain forests. The flowering periods of orchids are tackled. The phenological spectrum is saturated, whilst the phenogram indicates seasonal trends, with a maximum in November-December. Finally, epiphytic diversity confirms to be a suitable information for forest vegetation monitoring.