Growth, photosynthesis and carbon allocation pattern were studied in four dry afromontane forest tree species (Olea europea subspecies cuspidata, Podocarpus falcatus, Hagenia abyssinica and Juniperus procera) under varied light regimes in a greenhouse. The objective of the study was to assess the potential of the species for growth under forest canopies and to identify their habitat preferences. The light regimes were created using shade cloth and they corresponded with deep forest understoreys (2% of the light in the open gap); moderate shade (10%), slight shade as is found in edges of forest gaps (20%) and 100% representing open gaps.

Seedling biomass was significantly influenced by light regimes for all species as were total leaf area and relative growth rate. H. abyssinica had the highest growth rate but the lowest survival rate in shade. There was a consistent trend for higher specific leaf area (SLA) and leaf area ratio (LAR) at lower growth light regimes in O. europea and P. falcatus. O. europea and P. falcatus had similar allocation patterns whereby between 20-40% of the total biomass was allocated to stem, 20-30% to roots and 50-60% to leaves. In H. abyssinica up to 80% was allocated to leaves and only a small percentage to stem and to roots.

Within species there were significant differences in the light saturated rate of photosynthesis (Amax) per unit area among the plants grown at the lowest light level and in the open. For plants grown in the open there were very little among species differences in Amax per unit area. However, there were significant differences in the Amax of the different species grown at the lowest light level. Chlorophyll fluorescence measurements indicated that open-grown P. falcatus and O. europea experienced moderate photoinhibition. From the growth and photosynthesis results P. falcatus and O. europea appeared to be non-pioneer, shade-tolerant species, while J. procera and to a larger extent H. abyssinica showed pioneer, light-demanding characteristics. The results are discussed in terms of the occurrence of the species in the mosaic climaxes of afromontane forests.

In 1996, the first major biological surveys in the Itombwe Massif in over 30 years revealed that significant areas of natural habitat and remnant faunal populations remain, but that these are subject to ongoing degradation and over-exploitation. At least 10 areas of gorilla Gorilla gorilla graueri occurrence, including eight of 17 areas identified during the first survey of the species in the massif in 1959, were found. Seventy-nine gorilla nest sites were recorded and at least 860 gorillas were estimated to occupy the massif. Fifty-six species of mammals were recorded. Itombwe supports the highest representation, of any area, of bird species endemic to the Albertine Rift highlands. Twenty-two of these species were recorded during the surveys, including the Congo bay owl Phodilus prigoginei, which was previously known from a single specimen collected in Itombwe nearly 50 years ago. No part of Itombwe is officially protected and conservation initiatives are needed urgently. Given the remoteness and continuing political instability of the region, conservation initiatives must collaborate with traditional authorities based in the massif, and should focus at the outset on protecting the gorillas and limiting further degradation of key areas.