The patch of forest considered here is part of the Matandwe Forest Reserve, at the southern tip of the country. The hills rise abruptly 900 m above the level of the Lower Shire plain (the peak is at 945 m). Forest occupied the slopes facing north-east to south-east, and was most dense between 700 and 940 m. The soils are very shallow, with many boulders; a few ridges are covered with transition woodland or rock-loving communities (Aloe, Obetia, etc.). Along the main western ridge the edge of the forest was sharply defined and gave way suddenly to open woodland–much of it now planted with Toona ciliata. The forest was an example, unique in Malawi, of Zanzibar-Inhambane lowland rainforest community, the largest trees being Newtonia buchananii, Burttdavya nyasica and Khaya anthotheca (syn. K. nyasica).
Nearly 100 species have been recorded; the site was important for its population of Batis fratrum, estimated at over 100 pairs in 1983. In Malawi the species was otherwise only recorded from the Thangadzi valley (where riparian forest has been destroyed) and Lengwe (site MW021) where it was much scarcer and is probably extinct today. In addition, two species of the Zambezian biome have been recorded (see Table 3).
Non-bird biodiversity: Vegetation: 10 ‘Eastern’ woody plant species and two others occur nowhere else in the country; a species of Tricalysia and of Wrightia cannot presently be matched and fertile material is needed. Butterflies: amongst a forest fauna of some 35 species, Salamis cacta, Acraea quirina and Pentila tropicalis are found nowhere else in the country (they are Eastern elements). A. quirina reaches its southern limit here. Reptiles: a new species of dwarf chameleon (Rampholeon chapmani) was described recently (1992) and is not known from anywhere else. Some live specimens were transferred to a patch of forest on a private tea estate (Mikundi) in 1996 as the new species faced extinction in the Malawi Hills.
Pressure/threats to key biodiversity
In 1983 the lower edges of the forest (above Nsanje) suffered from inroads by fire, otherwise the main block was intact. In December 1999 the site was visited by J. Haugaard and L. D. C. Fishpool and found to be in a state of advanced degradation and whole-scale clearing for maize-fields. At the current rate of destruction, it is feared that the remaining forest could disappear within two years.