AMAZING USAMBARA MOUNTAINS.

East Usambara Mountains: An overview
Geographical history.
Amani Nature Reserve is located in the East Usambara region. This is part of the Eastern Arc Mountains, an isolated mountain chain of ancient crystalline rock formed through a cycle of block faulting and erosion, which stretches from the Taita Hills in Kenya down to the Southern Highlands in Tanzania. Due to their age, status as forest ‘islands’ and role as condensers of moisture from the Indian Ocean, the Eastern Arc forests are rich in endemic species (Hamilton, 1989). Many species have been geographically separated from their closest relatives for long periods. The mountains appear to serve both as a refuge for formerly widespread flora and fauna (Iversen, 1991) as well as centres of speciation (Fjeldsaa, 1997). Patches of forests, such as Amani Nature Reserve, have been likened to the African equivalent of the Galapagos Islands in terms of their endemism and biodiversity, therefore, considered to be one of the most important forest blocks in Africa.
Flora and fauna of the Usambara Mountains
Of the approx 3450 species of vascular plants recorded in the Usambara Mountains, over one quarter are likely to be endemic or near-endemic. In addition to the variety of plants, the mountains host a number of endemic or rare fauna species, including the Usambara eagle owl and a vivaparous frog species.
Human impacts
Over the past century, depletion of forests through logging activities and increasing clearance of forest areas for small-scale farm plots, has become a serious problem in forest management throughout the Usambaras. One of the most obvious and deleterious effects of this deforestation is soil erosion. The East Usambaras are an important water catchment area for lowland populations and so siltation through soil erosion causes a major problem for management in the area.
Amani Nature Reserve: facts & figures
Longitude/Latitude: 5°14’10’’ - 5°04’30’’ S, 38°30’34’’ - 38°40’06’’ E
Elevation: Approx 190 m – 1130 m above sea level
Topography: Catchment of Sigi river
Forest vegetation: Submontane, lowland and plantation forests
Forest area: The largest single block of forest in the East Usambara Mountains and is
connected to northern forest blocks only by the Derema forest corridor on public land
Hectares: 8360 ha
Status: Nature Reserve, gazetted in 1997, and a Man and Biosphere Reserve
Mean annual rainfall: 1,910mm per annum
Mean maximum temperature: 24.1 C
Mean minimum temperature: 16.3 C
UTM: 94 21640 - 94 39000 S, 45 0600 - 46 3200 E

Summary of biodiversity in Amani Nature Reserve
Please note this may not be a complete guide, but does give an idea of the species present.
Taxon
Total no. of species
% forest dependent
No. of non-forest species
No. of endemic species
No. of near-endemic species
No. of forest dependent endemics and near-endemics
Trees and shrubs
264*
367**
8***
43%
22
19
49
53
Mammals
59
(includes 16 bat species)
15.3%
6
0
3
2
Birds
65
33.8%
15
2
3
3
Reptiles
49
46.7%
6
3
15
17
Amphibians
27
66.6%
0
2
14
16
Butterflies
112
20.5%
4
1
10
9
Total
943
n/a
53
27
94
100

(Frontier)
* Species recorded in vegetation plots
**Species recorded opportunistically
***Species recorded in the regeneration plots only
History of Amani
Amani Nature Reserve was gazetted in 1997, amalgamating six forest reserves (Amani-Sigi, Amani-east, Amani-west, Kwamsambia, Kwamkoro and Mnyuzi Scarp), public land and 1068ha of forest donated by the East Usambara Tea Company into Tanzania’s first nature reserve.
History of Amani Botanical Gardens
The Amani Botanical Garden, was set up by the Germans in 1902 as an extensive arboretum of long-term botanical trial plots for exotic plant species. Species were introduced from various parts of the world for agricultural trials with different economic interests such as medicinal (ie Cinchona spp.), fruit and spices (e.g. Garcinic spp.), valuable timber (e.g Cedrela, Eucalyptus), cosmetic (ie Cananga), rubber, fibre, oil (e.g. Hevea) and ornamental (e.g. fan palms). In 1950, the Botanical Garden was closed by the British. Today a lot of these botanical plots are derelict and bear local naturalization (48 spp listed by Shiel in 1994). Alien species introduced by the Botanical Garden are a large conservation issue for the Amani Nature Reserve.
The Amani Botanical Garden has a gazetted area of 244ha, however, some parts are outside legal protection (106ha), the majority of which is occupied by National Institute for Medical Research (62ha) and 44ha is ungazetted public land. Encroachment into the botanical gardens has occured, especially in the non-gazetted areas. These include new buildings and other human activities such as grazing, vegetable gardens, are mainly all around Amani village where part of NIMR is located. The Amani Botanical Garden therefore has several stakeholders responsible for its management: the Ministry of Agriculture, TAFORI, NIMR which can complicate the situation.

FLORA OF THE EASTERN USAMBARAS & AMANI
Vegetation cover of East Usambara Mountains
• The East Usambara forests are composed of 13 forest blocks, although there are current efforts to link some of these with corridors.
• Approximately 45,137ha of the East Usambara Mountains remains as natural forest. 30.6% is classified as submontane rainforest and 63% as lowland forest. Altitude is the factor differentiating these forest types (Hamilton, 1989), with submontane forest generally occurring above 850m.
• Moreau (1935) stated that prior to European colonization in 1880’s, there was virtually a continuous forest cover on the mountains except for grassland habitat along the western ridge tops.

Land-use distribution in Amani Nature Reserve
Habitat type Area (hectares) % of area
Dense lowland forest 2199.2 35.5
Poorly stocked lowland forest 421.3 6.8
Dense submontane forest 2816.5 45.4
Poorly stocked submontane 1.8 0.03
Peasant cultivation 36.7 0.6
Cultivation under forest 18.1 0.3
Maesopsis plantation 508.5 8.2
Teak plantation 83.9 1.4
Tea plantation 6.5 0.1
Eucalyptus plantations 1.7 0.03
Bush 96.5 1.6
Settlement 7.3 0.12
Barren 1.5 0.02
Pond and rivers 1.1 0.02
Total 6200.6ha 100%
(Johansson and Sandy, 1996)
Note: This table does not include the public land and the 1068 ha of Tea Estate forest that was incorporated into the nature reserve.
Also not mentioned is that within the Submontane forests is small plantations of Japanese campher (Cinnamomum camphora).
Endemic plants in Amani
An estimated 23% of montane plant species are endemic to the Eastern Arc. Such species include 15 wild relatives of coffee and 20 African violet species. The most commonly recorded near-endemic tree and shrub species in Amani Nature Reserve are: Leptonychia usambarensis, Cephalosphaera usambarensis and Allanblackia stuhlmannii.
Allanblackia is commonly seen around the Amani field station, with large fruits up to 12 inches in length which may contain 40-50 seeds. The kernels produce a hard white fat can be extracted and used as soap or in cooking.
Introduced (aliens and invasive) species
Isolated "island" systems are thought to be most at risk from plant invasions. Localised naturalisation is quite common around Amani Nature Reserve as a result of the human encroachment and the Amani Botanical Gardens. Clidemia and Lantana are major invasives in Amani Nature Reserve. They may be influencing successionary processes because of their prevalence (Fowler and Nyambo, 1996). There are other species in Eastern Usambaras which are known to exhibit invasive tendencies elsewhere e.g. Grevillea, Casuarina, Cinnamomum, Cupressus. See the following section for a more complete list on the invasive plants in Amani.

Examples of introduced plants in Amani
• Cedrela odorata (Meliacae) has now spread from Amani Botanical Gardens to natural forest. Local communities plant it on their farms because it produces good timber tree. It originates from Neotropics and the Americas.
• *Clidemia hirta was introduced to Amani and has now spread to most forests in the surrounding areas. It is the only site in East Africa. It is a serious weed in other tropical moist areas, eg Hawaii. It originates from the Neotropics and the Americas.
• Elettaria cardamonum (Zingiberaceae) is now naturalised in derelict sites. Invasive in Sri Lanka, it originated in Asia.
• *Lantana camara (Verbenaceae) may inhibit regeneration in larger gaps. From Neotropics and the Americas. It is also invasive in forests in southern Africa.
• * Psidium cettoleauum (Guava) was considered the worst weed of closed forests. It may only be a recent introduction to Eastern Usambaras. Originates from Neotropics and the Americas.
• *Rubus Their fruit, called bramble fruit, is an aggregate of drupelets.
• *Phyllostachys bambusoides (Bamboo) from Asia.
• *Maesopsis eminii (see below).
• *Landolphia sp. This is commonly known as the Congo vine.

*These are species that are considered a problem or threat (naturalised).
Case study of an introduced species: Maesopsis eminii (Rhamnaceae)
• It occurs naturally in western Tanzania.
• First planted in 1913, it was a shade tree for Cephalospahera usambarensis (eg the Kwamkoro tea plot).
• About 580ha was also used for planting carried out to infill logging gaps.
• Seeds last approximately eight months. No one knows for sure what pollinates it.
• It was thought Maesopsis would not be able to regenerate naturally without management, but is now naturalized and dominates considerable areas of forest.
• Since the introduction of Maesopsis eminii into the area this species has spread rapidly in the Usambara Mountains particularly around Amani where there is concern that it may begin to dominate the forest (Binggeli, 1989). The high Maesopsis eminii density areas e.g. near the Kwamkoro Nature Trail, are the areas of forest where the species was originally planted, and/or forest edge plots.
• There has been much debate on the potential threat of this species, however, it is largely a pioneer species which doesn’t regenerate in the dense forest.

FAUNA OF AMANI
VERTEBRATES
Endemism
• There are 74 endemic vertebrates in the Eastern Arc (and another 18 endemic to lowland coastal Eastern Arc forests).
• Most of these 74 endemic vertebrates are forest dependent, including all the strict endemic bird, mammals and amphibians.

Mammals
The most commonly recorded small mammal species in Amani are shrews (Crocidura sp.) and African soft-furred rats (Praomys sp.). The most common larger species is the blue monkey (Cercopithecus mitis neumanni), while black and white colobus monkey (Colobus angolensis palliates) is also seen. In the evenings, bushbabies are commonly heard around the camp.
There are an estimated 16 species of bat from 5 families. Bat species that appear to be locally common are: Rhinolophus landeri lobatus, Rhinolophus hildebrandti, Hipposideros ruber, Miniopterus fraterculus and Pipistrellus grandidieri grandidieri.

Six percent of all Eastern Arc mammal species are endemic, most of which are threatened. In the Amani Nature Reserve, there are at least 24 species of mammals (excluding bats) from seven families. There are several species of special interest. These include:
• The restricted Zanj elephant shrew, Rhynchocyon petersi, which is common in the Usambara Mountains (Collar and Stuart 1987) yet listed as globally ‘Endangered’ by IUCN due to a decline in habitat extent and quality;
• The eastern tree hyrax, Dendrohyrax validus, listed as ‘Vulnerable’ by IUCN (Hilton-Taylor, 2000);
• The lesser pouched rat, Beamys hindei which is also considered ‘Vulnerable’ by IUCN (Hilton-Taylor, 2000);

Birds
Three percent of all bird species in the Eastern Arc are endemic. Within the East Usambara Mountains there is a high diversity with at least 110 forest bird species (Stuart 1989). There are a few globally-threatened avian species (Collar & Stewart 1985, IUCN 1996), all found in Amani region but at low densities.
Endemic birds of Eastern Usambaras
Common name
Scientific name
IUCN threat category
Usambara eagle owl
Bubo vosseleri
Endemic/ vulnerable
Dappled mountain robin
Arcanator orostruthus
Vulnerable
Long-billed apalis
Orthotomus moreaui
Critically endangered
Amani sunbird
Anthreptes pallidigaster
Vulnerable
Banded green sunbird
Anthreptes rubritorques
Vulnerable
Tanzanian mountain weaver
Ploceus nicolli
Endemic/ vulnerable
Sokoke scops owl
Otus ireneae
Vulnerable
East coast akalat
Sheppardia gunningi
Vulnerable
Mrs Moreau’s warbler
Bathmocercus winifredae
Endemic/vulnerable

Reptiles and Amphibians
With 7 chameleon species and 26 snake species, Amani Nature Reserve has a rich reptilian fauna.
The most commonly recorded reptile species are: The geckos (Cnemaspis africana and Cnemaspis barbouri), the skinks (Mabuya maculilabris, Mabuya striata, Lygosoma afrum, Leptosiaphos kilimensis), and an agama lizard (Agama agama).
Common chameleon species are: Bradypodion (Chamaeleo) fischer, Bradypodion (Chamaeleo) tenue, Chamaeleo dilepis, Chamaeleo deremensis, Rhampholeon brevicaudatus, Rhampholeon temporalis.
Common snake species are: Typhlops gierrai, Python sebae, Atheris ceratophorus, Elapsoidea nigra, Dendroaspis angusticeps, Lamprophis capensis, Buhoma (Geodipsas) vauerocegae, Aparallactus werneri, Natriciteres olivacea, Philothamnus macrops, Philothamnus hoplogaster, Crotaphopeltis tornieri, and Thelotornis capensis mossambicanus.
With 35 amphibian species Amani Nature Reserve has a particularly rich amphibian fauna, 8 of which are endemic (see below for full list).
FROGS
DESCRIPTION
Arthroleptis affinis
Medium sized, brown, forest floor, lay eggs in leaf litter
A.stenodactylus
Medium sized, brown, forest floor
Schoutedenella xenodactylus
Small, brown, forest floor
S.xenodactyloides
Small, brown, forest floor
Bufo brauni
Large, brown, forest floor, near stream
Nectophrynoides tornieri
Small, brown, forest floor, life-bearing
Afrixalus fornasini
Medium, brown, in pond, grey morphs, vertical pupils

A.uluguruensis
Medium, brown, in pond, grey morphs, vertical pupils
Hyperolius argus
Small, in pond, female: green, male: red/brown with spots, horizontal pupils, for all Hyperolius
H.mitchelli
Small, in pond, two light strips along flanks, light spots on ‘heel’
H.parkeri
Small, green/brown, in pond, with small spots
H.puncticulatus
Small, pond, various different types of spots on an orange background, often a mask on their face
H.spinigularis
Small, pond, green with light mask
H.tuberilinguis
Small, pond, brown/green, rare
H.viridiflavus mariae
Small, pond, red-grey, black eyes, red finger pads
Kassina maculata
Large, pond, under vegetation in mud, green/brown with darker spots, more heard than seen
K.senegalensis
Large, pond, under vegetation in mud, green/brown, with darker strips, more heard than seen
Leptopelis barbouri
Medium, treefrog, green-yellow with reddish eyes, only seen after rain when it descends
L.flavomaculatus
Large, treefrog, brown, commonly heard around the pond, green juveniles, vertical pupils
L.parkeri
Large, treefrog, grey-brown, red eyes, only seen after rain when it descends
L.uluguruensis
Medium, treefrog, blue throat and light spots on brownish coat, only seen after rain
L.vermiculatus
Large, treefrog, green or brown, usually has a dappled dorsal coat. Green juveniles
Callulina kreffti
Small, forest frog but tends to be found above the ground, stout, grey, warty-skin, expands as a defense mechanism
Hoplophryne rogersi
Small, forest frog, brown, breeds in water fulled-bamboo cups, quite common
Probreviceps macrodactylus
Large, treefrog, stout, short legs, brown, forest floor, releases sticky substance to attach itself to the female and as a defense mechanism
Arthroleptides martiensseni
Medium, forest floor, near streams, brown, usually with black strip over the eyes
Phrynobatrachus acridoides
Small, forest floor, brown
P.kreffti
Medium, stream, brown, males with yellow throat, is uncommonily diurnal
Ptychadena mascareniensis
Medium, pond, brown with green dorsal strip, long legs
Rana angolensis
Large, stream, brown-grey with loud deep croak, jumps very far
Xenopus muelleri
Medium, muddy-puddles, dark grey, only in water (aquatic), have claws and webbed feet
Xenopus laevis
Medium, muddy-puddles, dark grey, only in water (aquatic), have claws and webbed feet with tentacle under the eye
CAECILIANS (APODANS)
DESCRIPTION
Boulengerula boulengeri
Approx. 15cm, pink, burrowing, look like an earthworms, common
Scolecomorhpus vittatus
Approx. 45cm, dark blue with bright red on the ventral, come out on rainy nights, rare

The locally uncommon species that are both forest dependent and near-endemic or endemic species should be of conservation concern due to their low population density. There are ten such reptilian and amphibian species. These are: Bradypodion spinosum, Agama mossambica montana, Probreviceps macrodactylus, Urocotyledon wolterstorffi, Scelotes ulugurensis, Leptotyphlops macrops, Dipsadoboa werneri, Hyperolius mariae and Scolecomorphus vittatus.
INVERTEBRATES
The invertebrates are not well-studied and our current knowledge is probably strongly influenced by collecting effort. The insect fauna of the Amani region is diverse and includes some spectacular species. Butterflies are common in both open areas and in the forest, and a diverse range of species can be seen. Trails of driver ants (Formicidae: Dorylus sp.) will be encountered on roads and tracks, and the galleries and nests of termites (Isoptera) can be seen on tree trunks. Crickets (Gryllidae) are numerous in the forest, and can be heard almost everywhere. Other Orthoptera, including several families of grasshoppers, comprise a substantial component of the insect fauna.

Moths can easily be seen by the use of an illuminated sheet will attract a wide range at night from large and spectacular members of the families Saturnidae and Sphingidae to tiny Microlepidoptera. Other moth families that commonly come to light include the Arctiidae, Geometridae and Noctuidae. Beating and sweeping forest vegetation yields a rich insect fauna including many species of leaf beetles (Chrysomelidae) and weevils (Curculionidae) as well as bugs (Hemiptera). Pitfall trapping and sieving litter from the forest floor are good methods for collecting ground-inhabiting fauna. The dominant beetle groups are rove beetles (Staphylinidae) and dried fruit beetles (Nitidulidae), with some ground beetles (Carabidae) and a few dung beetles (Scarabaeidae). Cockroaches (Blattodea) are common in the litter.
Those invertebrate groups that have been studied in the East Usambara Mountains show high rates of endemism, especially those whose members have limited dispersal capability. Generally there tend to be great endemism in poor dispersers such as millipedes. At least 30 of the 41 species of millipedes (Diplopoda) found around Amani are believed to be endemic to the East Usambara Mountains. Of the terrestrial molluscs (Gastropoda) the East Usambaras has 55 endemic species of gastropods.
In a family of predatory wasps (Sphecidae), a considerably more mobile group, the proportion of endemic species is still high at 21%. Of the 112 species of butterflies recorded from Amani, two species are probably endemic, and a further nine are near endemic. While 20% of all butterfly species recorded are forest dependent, over 80% of the endemics and near endemics are forest dependent, and all are forest species. The spectacular Hypolimnas antevorta (Nymphalidae) is a large, blue-black and blue butterfly with white markings that is endemic to the East Usambaras and feeds on Urera hypselodendron (Urticaceae). Charaxes usambarae usambarae (Nymphalidae) is another large species, also endemic or near endemic that feeds on Albizia (Fabaceae). Forest ground beetles are likely to be endemic, as they are often flightless; a study in the nearby Uluguru Mountains, showed 94% of carabid beetle species believed to be endemic.
MANAGEMENT OF ANR
The forests of the East Usambaras have been under continuous exploitative human pressure for at least 2,000 years (Schmidt 1989). Until the last centuary, this pressure was sustainable (Kikula 1989). However, tea estates now employ roughly 4000 people in the high season and this growing human population is leading to increased pressure on the remaining natural forest in the area.
Amani Nature Reserve encompasses a large area within which there are numerous villages and sub-villages. People from the local communities are permitted to collect dead wood from the nature reserve for fuel-wood twice a week. Any changes in the management of Amani Nature Reserve will impact upon the adjacent communities; thus management decisions are not isolated to consideration of forest issues alone. Management issues are discussed at biannual Amani Nature Reserve Board meetings attended by representatives of all interested parties, including local communities.
Disturbance
Poles continue to be taken illegally from across the reserve. Areas of particularly high levels of new pole cutting are on the eastern side of the reserve. Evidence of pit-sawing is observed throughout the reserve however no active saw-pits are being recorded at the moment. Fire is a threat to specific areas of the forest; extensive patches of forest are continuously being burnt. Open grass/bushland habitats dominate in burnt areas. It is possible that the fires are limiting forest expansion within the Nature Reserve. The impact of fire is of serious concern on the southern and western borders of Amani Nature Reserve. Hunting continues illegally, the full impact of hunting on the populations of targeted species is unknown.
Conservation
The forests of the East Usambara Mountains are recognised as being part of a Biodiversity Hotspot (Myers et al, 2000), an Endemic Bird Area (ICBP, 1992), a Centre of Plant Diversity (WWF and IUCN) and a Globally Important Ecoregion (WWF), it is also a member of the Man and Biosphere Reserve network (MAB). These forests are a conservation priority due to their floral and faunal diversity, and to the high number of endemic species.

The forests of the East Usambara Mountains have been reduced to fragments within a matrix of agricultural land. Little forest remains outside of the gazetted forest reserves. For those species that are forest dependent, the forest reserves now provide almost the only available habitat. Amani Nature Reserve being the largest forest block in the East Usambara Mountains, has a lower risk of population extinction than smaller highly fragmented forest reserves. This gives Amani Nature Reserve a special value as a ‘pool’ of individuals of species. However, Amani is largely isolated from other forest reserves in the East Usambara Mountains, the only forested connection is the Derema forest corridor to translocate any species to repopulated other forested areas. At present, no legal status protects the Derema forest, other than basic legislation regarding water catchments and the felling of specific tree species. Recently there has been extensive discussion regarding the type of legislation that should be instated to protect the Derema forest corridor (pers. comm. Dr Veli Pohjonen, Jambiya. 2000.). The proposals range from gazetting the Derema forest corridor as a non-extractive forest reserve, to handing complete control of the forests to the local communities. From a biological perspective, effective protection of this only forested link from the largest block of forest (Amani) to more northerly forests is of up-most importance. However this decision is not purely based on biological considerations, social factors have to be taken into account to ensure the sustainable protection of the Derema forest corridor.