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Protected areas (National Parks), other reserves (Forest Reserves) and areas of private forest found within the 14 districts of the Eastern Arc Mountains of Tanzania, and number of forestry staff available for management (as of 2004)
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The Eastern Arc Mountains are renown in Africa for high concentrations of endemic species of animals and plants. Thirteen separate mountain blocks comprise the Eastern Arc, supporting around 3300 km2 of sub-montane, montane and upper montane forest, less than 30% of the estimated original forested area. At least 96 vertebrate species are endemic, s...
Contexts in source publication
Context 1
... example, the forest zone divisions are at lower elevations in the cloudy and maritime East Usambara Mountains (Moreau, 1966), whereas they are much higher in inland rain-shadow areas, where evergreen forest is limited to top plateaus (>2000 m). At lower elevations (regarded by Pó cs, 1976 as below 800 m on the Ulugurus, but below 500 m elsewhere) the sub-montane forest grades in species composition and physiognomy into that of the Table 1 -Location, area (km 2 ) ...Context 2
... addition there are seven proposed Forest Reserves (611 km 2 ), and 14 proposed village FRs (22 km 2 ) that are not legally gazetted. Privately managed forests cover around 177 km 2 and are found at Mazumbai (owned by Sokoine University), and within the tea estates of Ambangulu in the West Usambaras, Mufindi in the Udzungwa Mountains and Amani/Kwamkoro in the East Usambaras (Table 2). Within the human-dominated landscape outside the Reserves and private estates smaller patches of forest remain under traditional village authority. ...Context 3
... government analysis of problems affecting the management of the Eastern Arc reserve network in Tanzania has shown that the key constraints to effective conservation are the lack of long-term availability of funding and inadequate management capacity. Apart from meagre salary support, the Tanzanian government (both central and local) provides about $50,000 USD as operational funding to the 340 government staff who are tasked with the management of over 7000 km 2 of Forest Reserves of the Eastern Arc ( Burgess and Kilahama, 2005) (Table 2). The funds available from TANAPA to its two National Parks containing Eastern Arc mountain forest (Udzungwa and a small area in Mikumi) are much greater than that allocated by FBD. ...Citations
... Here, we document the elevational changes in an Afromontane forest bird community from Mount Kasigau, an isolated mountain SE of Kenya, and an Important Bird Area (Birdlife International, 2022) in the Eastern Arc mountains global biodiversity hotspot (Burgess et al., 2007;Mulwa et al., 2007;Myers et al., 2000). We used systematic bird ringing data over a 10-year period to assess community-level parameters at four elevation levels ranging from 858 to 1547 m. ...
Mt. Kasigau is the northeastern most of the Eastern Arc Mountains global hotspot and harbours some endemic and threatened species, but little is known about bird community changes along its elevational gradient. We assessed the relationship between bird biodiversity metrics, season, human disturbance, elevation and temperature using mist-netting data collected biannually over a 10-year period. Birds were sampled along the mountain's elevational gradient at four elevation levels (858, 1104, 1321 and 1547 m). Bird richness, diversity and evenness decreased with increasing altitude in both dry and wet seasons. Bird abundance declined with increasing elevation for the lower three elevation levels but peaked at the highest elevation. All diversity metrics were higher in the wet season compared to the dry season across all the years. Elevation had a greater effect on species assemblages than season, disturbance and temperature. Temperature had significant effects on abundance, diversity and richness, while disturbance had significant effects on diversity, evenness and richness. We conclude that bird assemblages in Mt. Kasigau are strongly shaped by elevational changes, while temperature and disturbance constitute important factors influencing bird conservation in the face of global warming. Our study highlights that elevation, disturbance and temperature influence bird assemblages along tropical el-evational gradients. K E Y W O R D S bird ecology,
... There is an urgent need to understand the forest recovery of East African TMFs, which are known for their high number of endemic plant and animal species, yet are under pressure from anthropogenic disturbances including conversion to agriculture (Burgess et al., 2007). Although a few studies have compared forest structure and diversity (e. g. ...
Tropical montane forests are fragile ecosystems that provide a wide range of ecosystem services including hydrological services, biodiversity protection and storing carbon in the above and belowground and soils contributing to climate change mitigation. The world's tropical montane forests are increasingly exposed to degradation and their recovery after disturbance has not been adequately quantified. Here, using information from 47 plots in three blocks of the Mau Forest Complex of Kenya, we assessed the changes in aboveground biomass (AGB), tree species diversity, soil carbon and nitrogen stocks following forest clearance. AGB recovered at an annual rate of 6.42 Mg ha − 1 yr − 1 in the first 20 years, the rate then slowed down to 4.46-4.67 Mg ha − 1 yr − 1 at around 25-30 years. Around 25 years after disturbance, AGB in recovering forests was 70 % (198.32 ± 78.11 Mg ha − 1) of the AGB in the old secondary forest (OSF) (282.86 ± 71.64 Mg ha − 1) and was statistically indistinguishable. Stem density, species diversity and richness indices did not show significant differences across recovery classes. There was no significant difference in soil carbon and nitrogen stocks across classes with the soil carbon (184.1 ± 41 Mg ha − 1) of the young secondary forest (<10 years) being 84.5 % of that of the OSF (217.9 ± 51.8 Mg ha − 1). This study reports a rapid rate of AGB and carbon accumulation within 20 years of disturbance, and high levels of species richness in these previously disturbed fragments of tropical montane forests of East Africa.
... Trees mostly use for APs (such as Albizzia lebbek, Tectona grandis, and Ficus glomerata) are examples of a diversified multipurpose tree community that offer not only a variety of products but also consistent nutrient cycling; this minimizes nutrient loss on fields, promote stable output and sustainable agriculture [41]. According to Msafiri et al. [42], excellent nitrogen fixers include Markamia obtusifolia, Acacia species, and Albizia schemperana, for instance, a tree leaf biomass of 400 kg/ha of dead matter might enhance the soil by returning 80-120 kg/ha of nitrogen, 8-12 kg/ ha of phosphorus, and 40-120 kg/ha of calcium to the soil each year through litter fall [43]. Two more advantages of raising soil organic matter through organic farming are improved soil quality and, as a result, increased agriculture's long-term viability. ...
Rapid population growth has caused severe food insecurity and environmental problems. For increasing food productions, synthetic chemicals have been in used. This has enhanced agricultural output, with unfavorable effects on the environment and biodiversity. Microorganisms in soil have been affected, and the effects of climate change have been detrimental. For the wellbeing of mankind, organic farming (OF) and agroforestry practices (APs) could be the best option due to their multidimensional contributions. Organic farming helps to maintain soil productivity and manage pests and weeds. Conversely, agroforestry blends trees with agricultural crops and offers advantages. Improved soil and crop yields, for environmental resilience and better socioeconomic conditions for farmers, are some of the multiple benefits of APs and OF. These methods can lessen the damaging effects of technology developments on the environment and biodiversity. Also, APs and OF provide sustainable solutions to the problems of food security and poverty. APs and OF are related, combining the two disciplines, the benefits could be substantially greater. Boosting APs and OF improve soil, lessen the effect of technological development in agriculture, and support sustainable development and improved livelihoods. If effectively implemented, APs and OF can act as links between habitats, and preserve biodiversity and its ecosystems.
... Countries such as Tanzania and Ethiopia host some of the oldest stable mountain ecosystems in the eastern branch of the rift system (Lovett and Wasser 1993, Lovett et al. 2005, Corti 2009), and therefore also hold disproportionate amounts of diversity compared with areas such as Kenya, which is mostly recent and volcanic (e.g. Baker 1988, Lovett and Wasser 1993, Lovett et al. 2005, Burgess et al. 2007, Siu-Ting et al. 2014). The relatively lower species richness in Kenyan Afrotemperate zones has been noted in different taxonomic groups (Diamond and Hamilton 1980, Rodgers et al. 1982, Scharff 1992, Brühl 1997, and this paucity has been named the 'Kenyan interval' (Poynton 1999: 498). ...
Discoveries of new species can greatly impact our understanding of the biogeography of a region. For example, groups of amphibian lineages restricted to the Afrotemperate forests of Tanzania and Ethiopia are indicative of a shared biogeographical history of this highly discontinuous ecosystem. Curiously, many of these lineages are absent from the geographically intermediate Kenyan highlands. This phylogeographical interval is generally considered to be attributable to the younger, volcanic origins of much of the Kenyan highlands, and thus an amphibian fauna that is derived largely from recent colonization events rather than comprising older relicts. Contrasting with this view, here we report on the discovery of a single specimen of Bufonidae (true toad) from Mount Kenya. The specimen belongs to a species new to science and deserves recognition at the generic level owing to its notable molecular phylogenetic and morphological divergences from other described taxa. It is most closely related to the Tanzanian genera Churamiti and Nectophrynoides. The discovery of this new toad and its association with Afrotemperate species is significant because it links Kenya to the biogeographically more ancient Tanzanian mountains and supports the potential longevity of the Afrotemperate forests in Kenya. Broadly, it highlights that we are still adding major branches to the phylogeny of anurans.
... The Eastern Afromontane Biodiversity Hotspot (EABH) is one of the richest centres of biodiversity on Earth (Mittermeier et al., 2011). It is composed of a discontinuous chain of several mountain ranges, sometimes referred to as an 'archipelago of sky-islands', spreading from southwest Saudi Arabia and Yemen southward to Mozambique and Zimbabwe Plio-Pleistocene climatic cycles (Burgess et al., 2007), which resulted in their very high biodiversity. Similarly, the Eastern Arc Mountains are old (10-40 My) in southern Kenya and Tanzania. ...
Aim: The Eastern Afromontane Biodiversity Hotspot (EABH) offers an ideal location to investigate the evolutionary mechanisms producing a high level of endemic biodiversity. We tested the hypothesis that the cradle of Eastern Afromontane diversity is in the largest sub-region of the EABH montane archipelago, that is the Ethiopian Highlands. Further, we expected that climate oscillations followed by elevational shifts in montane habitats facilitated the dispersal of small mammal populations across unsuitable arid lowlands.
Location: Mountains and highlands of East Africa.
Taxon: Shrews of the genus Crocidura (Eastern Afromontane phylogenetic clade).
Methods: We collected comprehensive genetic data from 511 (mitochondrial gene for cytochrome b) and 147 (double digest Restriction-Associated DNA sequencing) samples of Crocidura shrews across the EABH. We estimated phylogenetic relationships with Bayesian and Maximum Likelihood approaches. Population genetic analyses were performed in STRUCTURE to evaluate the internal structure of species outside Ethiopia. Ancestral area and dispersal routes were analysed by the BioGeoBears package.
Results: Six major phylogenomic clades were delimited based on concatenated nuclear loci. The mitochondrial phylogeny roughly matches nuclear phylogenies, but with poorer resolution. Five of the six revealed clades are restricted to the Ethiopian Highlands, which is unambiguously the cradle of the diversity of this group of mammals (also confirmed by the biogeographic analysis). All non-Ethiopian and a single Ethiopian species fall into the sixth clade with poorly resolved internal relationships. Detailed population genetic analysis of SNP data revealed a pronounced structure with multiple gene pools in this clade; however, this structure only partly corresponds with the current taxonomy.
Main Conclusions: Eastern Afromontane Crocidura shrews originated in the Ethiopian Highlands. They radiated there, and through a single southward dispersal event across the Turkana depression, they colonised the rest of the EABH in response to diverse geomorphology and climatic changes during the Plio-Pleistocene.
... Unfortunately, over 70% of its forests are degraded due to illegal timber harvest, forest fires, expansion for agriculture, mining and biological invasions (Burgess et al. 2000, Newmark 2002, Hulme et al. 2013. As a result, ≥ 800 vascular plants and ≥ 96 vertebrate species occurring nowhere else in the world may be at risk of extinction (Myers et al. 2000, Burgess et al. 2007, Newmark & McNeally 2018. The protected forests in the EAMs provide important habitat for rare flora and fauna. ...
... (Fig. 2). This endemic species-rich natural forest is distinguished by two rainy seasons with high relative humidity, with extensive rains from March to May and short rains from October to December (Burgess et al. 2007 (Howell et al. 2021). AFNR is also an important habitat for Montane forest-adapted rodents, such as the soft-furred mouse (Montemys delectorum) (Bryja et al. 2013). ...
The Eastern Arc Mountain forests are recognised as the richest forests for biodiversity in mainland Africa. However, disturbances, particularly invasive plants, reduce the capacity of these forests to support biodiversity conservation. This study investigated the abundance, diversity and community composition of rodents in forest sites invaded and uninvaded by Maesopsis eminii in Amani Forest Nature Reserve. Rodents were captured through a capture-mark-recapture technique, using 300 Sherman traps located in invaded and uninvaded forest sites. A generalised linear model was applied to assess patterns in rodent community composition in invaded and uninvaded forest sites. The results indicated that the invasion by M. eminii significantly affected the diversity and assemblage of rodents, thereby reducing the abundance of Beamys hindei, suggesting that the invasive tree may be affecting various aspects of the rodent’s life. We recommend taking measures to prevent the spread of M. eminii into the uninvaded parts of the reserve to reduce habitat loss for rodents and other native species.
... These topographical uplifts also have indirect effects via the modification of climate (Sepulchre et al., 2006). In Africa, mountains harbour high levels of species diversity and endemism (Fjeldså and Lovett, 1997;Burgess et al., 2007). East Africa, which has the highest topographical complexity compared to the rest of Africa, has been inferred to be rich in both neo-and palaeo-endemics (Dagallier et al., 2020). ...
Background and aims:
Throughout the Cenozoic, Africa underwent several climatic and geological changes impacting the evolution of tropical rain forests (TRF). African TRF are thought to have extended from East to West in a 'pan-African' TRF, followed by several events of fragmentation during drier climate periods. During the Miocene, climate cooling and mountain uplift led to the aridification of tropical Africa and open habitats expanded at the expense of TRF, which likely experienced local extinctions. However, in plants, these drivers were previously inferred using limited taxonomic and molecular data. Here, we tested the impact of climate and geological changes on diversification within the diverse clade Monodoreae (Annonaceae) composed of 90 tree species restricted to African TRF.
Methods:
We reconstructed a near complete phylogenetic tree, based on 32 nuclear genes, and dated using relaxed clocks and fossil calibrations in a Bayesian framework. We inferred the biogeographic history and the diversification dynamics of the clade using multiple birth-death models.
Key results:
Monodoreae originated in East African TRF ca. 25 million years ago (Ma) and expanded toward Central Africa during the Miocene. We inferred range contractions during the middle Miocene and document important connections between East and West African TRF after 15-13 Ma. Our results indicated a sudden extinction event during the late Miocene, followed by an increase in speciation rates. Birth-death models suggested that African elevation change (orogeny) is positively linked to speciation in this clade.
Conclusion:
East Africa is inferred as an important source of Monodoreae species, and possibly for African plant diversity in general. Our results support a "sequential scenario of diversification" where increased aridification triggered extinction of TRF species in Monodoreae. This was quickly followed by rain forests fragmentation, subsequently enhancing lagged speciation resulting from vicariance and improved climate conditions. In contrast to previous ideas, the uplift of East Africa is shown to have played a positive role in Monodoreae diversification.
... EAMs are home to a number of forest types including lowland and montane forests that provide habitat for a range of plant and animal species. However, deforestation due to timber and charcoal production as well as agriculture, mining and settlement, has resulted in significant loss of forest cover in the region (Burgess et al., 2007). The EAMs harbour a number of plant and animal species that are considered endangered or critically endangered including Uluguru ...
... For example, the invasive vine Lantana camara and Maesopsis eminii have shown negative impact on native plant species in the EAMs (Burgess et al., 2007). On the other hand, climate change is expected to have significant impacts on the vegetation and biodiversity of the EAMs including changes in rainfall patterns and temperature regimes. ...
... The EAMs are a range of isolated, high-elevation mountains in East Africa, known for their unique climate and weather conditions. The region is characterized by a complex system of microclimates, with variations in temperature, precipitation, and cloud cover depending on elevation, aspect, and local topography (Burgess et al., 2007& EAMCEF, 2018. For instance, ...
The study aims to assess current population status, ethnobotanical values, and genetic variation for conservation of A. stuhlmannii across environmental, land tenure and land use gradients in Eastern Tanzania
... Although the genus occurs in a range of habitats, many of these range-restricted species are endemic to specific mountain ranges. For example, the Eastern Arc Mountains of Kenya and Tanzania -well known for their exceptionally high biodiversity and endemism (Burgess et al. 2007;Gereau et al. 2016 (Darbyshire 2009;Darbyshire et al. 2010). ...
Isoglossa pareensis I.Darbysh. & Hemp (Acanthaceae), from submontane moist forest at Mwala in the South Pare Mountains of northeastern Tanzania, is described and illustrated. This species is considered to be related to I. gregorii (S.Moore) Lindau and I. punctata (Vahl) Brummitt & J.R.I.Wood, which are widespread in the montane forests of eastern Africa, but it clearly differs from these species in inflorescence structure and indumentum and in anther morphology. Notes on the habitat requirements and extinction risk of this new species are provided; it is considered to be Vulnerable under IUCN criterion D2 because of its extremely limited range and a plausible future threat from wildfires. The recent discovery of the Critically Endangered acanthaceous herb Asystasia masaiensis Lindau at lower, drier elevations at the same site is also reported and the first known photograph of that species is reproduced
... The African Udzungwas are the key mountain range within the Eastern Arc Mountains that stretch from the Taita hills of Southern Kenya to Makambako Gap in Southern Tanzania. They have been hailed as the ' African Galapagos Islands', because they show stunningly high rates of endemism, and hold about onethird of Tanzanian biodiversity, which is currently at great risk owing to deforestation and loss of primeval habitats (Bjørndalen 1992, Burgess et al. 2007, Hall et al. 2009, Kideghesho et al. 2013. The wet season lasts from November to May, but the annual rainfall is much lower compared with that of the Western Ghats, ranging from 600 mm on the north-west slopes to 2000 mm in the eastern parts of the range. ...
Green, brown and black pigments are uncommon in the otherwise typically yellow to orange Echiniscidae. Viridiscus, a genus currently represented by a handful of species, in which cuticular coloration varies from a light green through dark green to almost black, has been an exception. Here, we uncover a new echiniscid lineage from the primeval subtropical and tropical rainforests of India and Tanzania, comprising three species with a caramel/brown body. Given that both Viridiscus and the new species complex lack dorsolateral trunk appendages and share dark cuticular pigmentation, they may be mistaken for each other. However, a closer inspection of the dorsal cuticular sculpture and molecular phylogenetic analyses indicate that the new complex belongs within the Echiniscus spinulosus morphogroup. Thus, the presence of dark pigments in two indirectly related lineages is evidence for the convergence of dark cuticular coloration in limno-terrestrial heterotardigrades. We detected three species in the new complex: Echiniscus brunus sp. nov., from the Western Ghats (Tamil Nadu, India), and two other candidate species, Echiniscus aff. brunus sp. can. 1 and Echiniscus aff. brunus sp. can. 2, from India and Tanzania, respectively. We refrain from describing the two latter species formally because they exhibit little or no morphological differences, which is yet another clear case of the crucial role of DNA barcoding in an accurate estimation of tardigrade species richness.
