Most of the natural vegetation in Thyolo District disappeared with the establishment of extensive tea estates around the beginning of the twentieth century. It must have consisted largely of moist Brachystegia or transition woodland (miombo interspersed with evergreen species), with rainforest in stream depressions and on the summit of Thyolo Mountain. Forest existed in a continuum down to the lower levels (c.1,000 m) around the mountain. This is no longer the situation, but a dozen patches of lowland rainforest have been preserved privately amid the tea fields to the north-east and within 2–10 km of Thyolo Mountain. They lie in stream depressions, at c.1,050 m, with a tall canopy of mainly Albizia gummifera and Khaya anthotheca (syn. K. nyasica). The three most important patches visited in the 1980s were on the estates of Mwalantunzi (93 ha), Namingomba (80 ha) and Mikundi (40 ha).
See Box and Tables 2 and 3 for key species. Some 50 species have been recorded so far; these forest remnants are important for their relatively high densities of Apalis chariessa (6–7 pairs/100 ha) and Oriolus chlorocephalus (4–7 pairs/100 ha). In addition, one species of the Zambezian biome occurs (Table 3) while five Afrotropical Highlands biome species are winter visitors; see Table 3.
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
Most forest patches left on the tea estates have been more effectively protected than the adjacent Forest Reserve on Thyolo Mountain. Their present status, however, needs reassessment and contact must be established with the managers of the tea estates concerned, to stress the scientific importance of ‘their’ forests; the main reason for their retention so far has been for conserving water.