Plants

The vegetation varies widely, however the most widespread vegetation types found are tropical lowland rainforest, tropical montane rainforest and Puna vegetation (grasslands). The lowland forests occur on the alluvial plains and the interfluvial hills. Those on the hills may experience seasonal water supply, given the monthly variation in rainfall, while the forests on the alluvial plains are likely to be seasonally flooded. The montane forests experience less variation in the water supply and are exposed to lower temperatures. The management plan (La Molina, 1986) maps 14 forest types using the Holdridge system (after Tosi, 1960), although, given the lack of rainfall data, this must be to some extent speculative. Despite the high diversity of plant species in this region, the flora of Manu is still poorly known and floristic inventories must be considered as preliminary (Gentry, 1985). The few collections of plants are those of Foster (1985) and Gentry (1985) made in the alluvial plains near the Biological Station, and in the Tres Cruces region of the uplands. Other collections have been made by Terborgh (1985) and Janson (1985) on trees where birds and primates obtain food. Despite this, in the last ten years, 1147 plant species have been identified in the park within quite a small area (500 ha), and it is likely that the number of species to be found within the park is well over this figure. More recent data (Saavedra, 1989) indicate 1,200 lowland vascular species and a single one hectare plot near the Cocha Cashu research station supported more than 200 tree species.