The 950 hectares (2,300 acres) Chirinda Forest Botanical Reserve is situated on the slopes of Mount Selinda, 30 km (19 miles) south of Chipinge, in the Chipinge Highlands of Manicaland, Zimbabwe,[2][3] and is administered by the Forestry Commission.[4] The reserve is situated at between 900 and 1,200 m (3,000 and 3,900 ft) in altitude,[5] and receives some 1,370 mm (54 in)[6] to 1,466 mm (57.7 in) of annual rainfall. 606 hectares (1,500 acres) of its higher levels, above 1,076 m (3,530 ft), is covered by moist evergreen forest,[7] specifically Zanzibar-Inhambane transitional rain forest,[8] of which it represents the southernmost occurrence. The headwaters of three streams, namely the Zona, Chinyika and Musangazi, drain the two broad highlands which it encloses. The boundaries of the reserve are not strictly enforced, so that cattle grazing and plant harvesting are ongoing.[5] The reserve is surrounded by communal settlements, commercial timber plantations (eucalypts and pines) and small-scale commercial farming units. The naturalist Charles Swynnerton was appointed manager of the nearby Gungunyana farm in 1900, and a number of plant, bird and insect names commemorate his collecting activities of the next two decades.[9] Chirinda means "lookout" or "vantage point" in the chiNdau language, or perhaps "place of refuge".[10]
Ecology
The medium altitude forest is likely the southernmost patch of subtropical rainforest in Africa. Phytogeographically it is classed as Afromontane forest, but with lowland and Guineo-Congolian elements. It is situated on two hill tops on dolerite-derived soils, and Müller (1991) proposed that these soil types determine its extent.[7] Goldsmith (1876) however suggested that it is only a relic of a once much larger forest which has been reduced by gradual climatic changes in a few hundred years.
Year-round moisture, in the form of rain, mist or dew, provides for a substantial and intact moist leaf litter layer, on which its ecological processes depend. Decomposition is fungal, and not by termites or similar insects as would be the case in drier woodlands of the region.[7] Several tree species bear fleshy fruit, resulting in a good representation of mammal and bird frugivores,[7] which impact both negatively and positively on seed dispersal. Much of the fauna shows affinities to forests elsewhere, particularly those at lower altitudes along the East Africa coastal plains.[7]
Protection
Protection from fires is expected to facilitate the regeneration and expansion of the forest. During his time of residence, Swynnerton noted that recurring fires had been gradually reducing outlying forest patches. Destruction of portions of the Chipete and Chipungambira satellite forest patches occurred during the 1860s.[11] It may have been aided by elephants which opened up forest, but more likely resulted from indigenous people who regularly cleared land by fire in spring time.[11] Fire-resistant mobola plum and mahobohobo trees are pioneer species in such areas.[11]
Maupare (1993) however noted that the forest boundary was stable and that former logging operations in the northern section had no lasting effect on the plant diversity.[11] This extraction of red mahogany, peawood and tannodia during the 1940s also had little effect on its extent.[7]
Flora and fauna
The area is home to a high diversity of plants,[12] fungi, birds, butterflies, insects and reptiles.
Samango monkeys are regularly seen, and leopard on the odd occasion. The local races of the mutable sun squirrel (H. m. chirindensis) and red-bellied coast squirrel (i.e. Selinda mountain squirrel, P. p. swynnertoni) are mountain isolates.[7] The Selinda veld rat occurs in tangled vegetation on rocky areas, and is only known from two other sites in Zimbabwe.[16]
The reptile fauna includes pythons, cobras, vipers, mambas, adders, chameleons, geckos, skinks and lizards. Marshall's leaf chameleon, an endemic of the Eastern Highlands, is found within the forest and along its margins. The type speciesC. swynnertoni of the worm lizard genus Chirindia was described from this locality, while another worm lizard, Zygaspis ferox, is endemic to the forest and its vicinity.[22]
The Mount Selinda acraea mimic butterfly (Mimacraea neokoton) is found nowhere else.[7] The type of the ebony bush brown was obtained from Chirinda forest, and it is also known from the Vumba. It flies all year and has distinct seasonal forms.[23] The Chirinda bush brown is named for the forest, but it is in fact a widespread species. Its type was obtained at an unknown location in the Eastern Highlands, and it is distinguished from the previous species by its lighter upperside ground colour, and the contrasting hair-pencils of the male.[23]
Facilities
The well-marked route to the campsite leaves the main road just east of the mission hospital in Mount Selinda. It is located 4 km into the forest, and also has chalets with clean facilities and braai stands.[15]
Mapaure I (1997). A floristic classification of the vegetation of a forest-savanna boundary in south-eastern Zimbabwe. Bothalia 27(2):185-195.
Mujuru L, Kundhlande A (2007). Small-scale vegetation structure and composition of Chirinda Forest, southeast Zimbabwe. Afr. J. Ecol. 45:624-632.
Müller T (1991). Rainforests of Zimbabwe. Unpublished report, National Herbarium and Botanic Garden, Department of Research Specialist Services, Harare.
Swynnerton, CFM (1918). Some factors in the replacement of the ancient East African forest by wooded pasture land. S. Afr. J. Sci. 14, 493-518
Timberlake J (1991). Tour report - Chirinda, Haroni and Rusitu Forests. Internal report, Forest Research Centre, Harare.
Timberlake J (1992a). Findings from a comparison of aerial photographs of Chirinda forest from 1959 to 1987. Unpublished Report, Forest Research Centre, Harare.
Timberlake J (1992b). Chirinda Forest: Conservation of a Rainforest in Zimbabwe. Paper presented at the SAREC International Symposium on Ecology and Conservation of Indigenous Forests, July 1992, Victoria Falls, Zimbabwe.
Timberlake J (1994b). Changes in the extent of moist forest patches in the Eastern Highlands: Case studies based on aerial photographs. Forest Research Paper No. 7. Forestry Commission, Harare.