The Chagga home gardens – Relict areas for endemic Saltatoria species (Insecta: Orthoptera) on Mount Kilimanjaro

doi:10.1016/j.biocon.2005.03.018

Biological Conservation

Volume 125, Issue 2, September 2005, Pages 203-209

https://doi.org/10.1016/j.biocon.2005.03.018 Get rights and content

Abstract

The sub-montane cultivation belt, with its so-called Chagga home gardens on Mount Kilimanjaro, was investigated for its Saltatoria fauna. Since these cultivated fields still have the structure of a forest, differing mainly in the undergrowth, more than half of the 52 recorded species are forest species, whilst the remainder originate from open habitats. Moreover, the Chagga home gardens harbour >70% of all forest species and >50% of the endemic species of Mount Kilimanjaro. Most endemics in the plantations originate from sub-montane habitats, and contribute 72% of the total number of sub-montane endemics found in the region. More than half of all endemics from the montane zone are also found in the Chagga home gardens. Therefore, the Chagga home gardens act as an important refuge for both generalist forest species and endemic fauna. In recent years, new coffee varieties have been introduced to the gardens that are less shade demanding, and tree removal may impinge on the indigenous Saltatoria fauna.

Introduction

The sub-montane slopes of Mount Kilimanjaro have been affected by man for at least 2000 years (Schmidt, 1989), but in the last century the population has increased from 50 to 60,000 (Widenmann, 1899) to over 1 million in 2002 (National Bureau of Statistics, 2003). The sub-montane forest, which covered the area in former times (Volkens, 1897) has gradually been replaced by agricultural fields, the so-called Chagga home gardens, and natural forest has been restricted to inaccessible gorges and along rivers.

The Chagga home gardens are cultivated by a traditional and sustainable system using the different vegetation strata. The tree layer consists of many indigenous species from the former sub-montane forest communities e.g., Albizia schimperiana, Olea capensis or Ekebergia capensis (Hemp, in press), and they are harvested for firewood, timber and livestock fodder, as well as providing shade for the coffee trees cultivated as a cash crop. Several varieties of banana are also grown with various vegetable crops below. Plants and animals, including insects, are also used for medicinal purposes (Hemp, 1999, Hemp, 2001c).

The aim of the present study is to investigate the refuge function of the forest-like Chagga home gardens for the Saltatoria fauna of Mount Kilimanjaro.

Section snippets

Methods

Mount Kilimanjaro is situated at the northern Tanzanian border with Kenya (between 2°45′ and 3°25′S and 37°00′ and 37°43′E), and rises to altitudes of nearly 6000 m. The following ecological zones have been described (Hemp, 2001): wet and arid savanna habitats (800–1000 m); dry to moist meadows, as well as shady banana plantations of the sub-montane cultivation belt (1000–1800 m); clearings, differently disturbed and undisturbed forests in the montane zone (1800 – ca. 3000 m); and (sub)alpine

Results

192 Saltatoria species were recorded for the whole of Mt. Kilimanjaro, the majority in grassland (130 species), followed by waste land (includes fallow arable land, roadsides and open disturbed places) with 83 species, forests with 38 species, and clearings with 47 species (Fig. 2). The Chagga home gardens form an important habitat in respect to biodiversity, with 52 species, about a quarter of the whole Saltatoria fauna (Table 1). Comparatively few species were found in swamps (14 species) and

Discussion

The multi-layered Chagga home gardens retain a forest-like structure, so it might be expected that they would contain forest species; indeed >70% of the 52 species recorded from the Chagga home gardens were typical of forest or forest-edge situations. An important find was that forest canopy dwellers can persist in these plantations (Fig. 3). Species of the undergrowth are also frequent inhabitants, favouring the more open areas. Since the forest-like Chagga home gardens are most luxuriant in

Acknowledgements

I thank the Commission for Science and Technology of Tanzania, Dar es Salaam, for granting the research clearance and the Deutsche Forschungsgemeinschaft for funding. Many thanks also to two anonymous reviewers.

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Biological Conservation

Abstract

Introduction

Section snippets

Methods

Results

Discussion

Acknowledgements

References (15)

An ethnobotanical study on Mt. Kilimanjaro

Ecotropica

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Plant Biology

Aerotegmina, a new genus of African Listroscelidinae (Orthoptera: Tettigoniidae, Listroscelidinae, Hexacentrini)

Journal of Orthoptera Research

Two new species of Amytta Karsch (Orthoptera: Meconematinae) from East Africa (Tanzania, Mt. Kilimanjaro)

Journal of Orthoptera Research

Ethnozoological research on invertebrates on Mt. Kilimanjaro, Tanzania

Ecotropica

Ecology of the pteridophytes on the southern slopes of Mt. Kilimanjaro. Part I: Altitudinal distribution

Plant Ecology

Cited by (32)

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Traditional agricultural gardens conserve wild plants and functional richness in arid South Sinai

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