Bale Mountains Research Articles

Variation in population structure and dynamics of montane forest tree species in Ethiopia guide priorities for conservation and research

AbstractThe greatest extent of Afromontane environments in the world is found in Ethiopia. These areas support exceptional biodiversity, but forest cover and ecological integrity have declined sharply in recent decades. Conservation and management efforts are hampered in part by an inadequate understanding of the basic ecology of major tree species. We investigated population structure and inferred population dynamics from size frequency distributions of 22 forest tree species encountered in montane forests of Ethiopia. We collected new empirical data from four sites in the Bale Mountains, where some of the country's most extensive and least disturbed forests remain, and conducted a systematic review and analysis of all such studies that reported population structure for one or more of these species in Ethiopia. Thirteen widespread montane tree species showed a reverse‐J size distribution, indicating a relatively stable population structure. Six other species had size‐frequency distributions that indicate episodic recruitment and/or removal of certain size classes. Specific causes of these patterns are uncertain: they may involve timber harvesting, herbivory, fire, or natural disturbances, but patterns were inconsistent and locality dependent. For three other tree species, existing data are inadequate for any interpretation of population structure and dynamics. A species of particular conservation concern that emerged from this analysis was Hagenia abyssinica, which was found in all areas to consist only of larger individuals with no recent recruitment. For management and conservation purposes, the species in most urgent need of new research are those with inadequate or inconsistent data, and H. abyssinica.

Daily activity patterns in the giant root rat (Tachyoryctes macrocephalus), a fossorial rodent from the Afro‐alpine zone of the Bale Mountains, Ethiopia

AbstractRodents adjust their activity to environmental conditions. The adjustment can be especially pronounced in climatically challenging environments. We studied activity patterns in the free‐living giant root rat (Tachyoryctes macrocephalus), a large fossorial rodent endemic to the Afro‐alpine ecosystem of the Bale Mountains, Ethiopia, by means of radio telemetry. We radio‐tracked 17 adults during two periods of a dry season differing in temperature and food supply. In both periods, root rats spent a large part of the day (around 79%) in their underground nests. The proportion of time the animals were active aboveground decreased from 6.9 to 3.8% between the early and late dry season, which contradicts our prediction that aboveground activity would increase under lower food supply. We propose that there are thermoregulation advantages of prolonged aboveground activity during warm hours in the colder early dry season. In both periods, the root rats displayed diurnal activity with a unimodal pattern positively related to the temperature at the soil surface. Unlike in some other burrowing rodents, there was no tendency to decrease activity in the warmest part of the day even in the relatively warm late dry season.

Orthoptera (Insecta: Tettigonioidea, Pyrgomorphoidea, Acridoidea) of Kafa Biosphere Reserve, Bale Mountains National Park and other areas of conservation interest in Ethiopia.

An annotated checklist of 51 Orthoptera taxa (Tettigonioidea, Pyrgomorphoidea and Acridoidea) of Kafa Biosphere Reserve, Bale Mountains National Park and some additional sites in Ethiopia is presented. Ten species are newly recorded for the country. Four species are new to science: Peropyrrhicia attilioi n. sp., P. keffensis n. sp., P. semiensis n. sp. and Coryphosima danieli n. sp. The status of Peropyrrhicia cooperi Uvarov, 1934 and P. scotti Uvarov, 1934 is revised: both are considered valid species.

Feasibility and efficacy of oral rabies vaccine SAG2 in endangered Ethiopian wolves

Diseases are a major cause of population declines in endangered populations of several canid species. Parenteral vaccination efforts to protect Ethiopian wolves (Canis simensis) from rabies have targeted the domestic dog reservoir, or the wolves themselves in response to confirmed outbreaks. Oral vaccination offers a more cost-efficient, safe and proactive approach to protect Ethiopian wolves and other threatened canids from rabies. Field trials of the oral vaccine Rabigen® SAG2Dog were undertaken in the Bale Mountains of southeastern Ethiopia. Four different bait types and three delivery methods were tested in twelve Ethiopian wolf packs, and the oral vaccine (using the preferred bait) was trialled in three packs. Vaccine uptake and immunization rates were measured through direct observations and in live-trapped animals through the assessment of biomarker levels and serological status. Commercial baits were never taken by wolves; goat meat baits had the highest uptake, compared to rodent and intestine baits. Targeted delivery from horseback and nocturnal delivery within a pack’s territory performed favourably compared to random bait distribution. Bait uptake by non-target species was lowest during the nocturnal blind distribution. Of 21 wolves trapped after vaccination, 14 were positive for the biomarker iophenoxic acid (i.e. ingested the bait and most likely pierced the sachet with the vaccine). Of these, 86% (n=12/14) had levels considered sufficient to provide protective immunity to wildlife (⩾0.20IU/ml), and 50% (n=7/14) demonstrated antibody titres above the universally recognised threshold (⩾0.5IU/ml) -the baseline average was 0.09IU/ml (n=12 wolves). All but one of the wolves vaccinated in 2014 were alive 14months later. Our trials confirm the potential for SAG2, delivered in a goat meat bait, to effectively protect Ethiopian wolves against rabies, supporting the initiative for a more efficient and proactive approach to manage and eventually eliminate rabies in Ethiopian wolf populations.

Effects of livestock grazing on an Afromontane grassland bird community in the Bale Mountains of Ethiopia

AbstractLivestock grazing has been considered to be one of the major causes for biodiversity degradation worldwide. In this study, we examined this effect on Afromontane grassland birds by comparing their diversity between ungrazed and grazed grassland sites in the northern Bale Mountains, Ethiopia. We counted birds and recorded vegetation height and cover along 28 (14 in each land‐use type) 1 km transects. We used six different diversity measures (richness, evenness, Shannon diversity, taxonomic diversity and taxonomic distinctness) to express bird diversity and explored which of these measures better reveal the diversity pattern. Vegetation structure differed significantly between the two sites; the first two principal components accounted for 78% of the variation. Discriminant function analysis (DFA) showed bird diversity to differ significantly between the two sites; taxonomic diversity (Delta) contributed the most to the difference between the two sites, while species richness contributed the least. The results of ANOVA indicated that all diversity measures, except species richness, were significantly higher in the protected site compared to the unprotected site. In general, this study showed that grazing had negatively affected bird diversity in the study area and the use of taxonomic diversity measures had enabled us to reveal the impact better.

Microbial eukaryote plankton communities of high-mountain lakes from three continents exhibit strong biogeographic patterns.

Microbial eukaryotes hold a key role in aquatic ecosystem functioning. Yet, their diversity in freshwater lakes, particularly in high-mountain lakes, is relatively unknown compared with the marine environment. Low nutrient availability, low water temperature and high ultraviolet radiation make most high-mountain lakes extremely challenging habitats for life and require specific molecular and physiological adaptations. We therefore expected that these ecosystems support a plankton diversity that differs notably from other freshwater lakes. In addition, we hypothesized that the communities under study exhibit geographic structuring. Our rationale was that geographic dispersal of small-sized eukaryotes in high-mountain lakes over continental distances seems difficult. We analysed hypervariable V4 fragments of the SSU rRNA gene to compare the genetic microbial eukaryote diversity in high-mountain lakes located in the European Alps, the Chilean Altiplano and the Ethiopian Bale Mountains. Microbial eukaryotes were not globally distributed corroborating patterns found for bacteria, multicellular animals and plants. Instead, the plankton community composition emerged as a highly specific fingerprint of a geographic region even on higher taxonomic levels. The intraregional heterogeneity of the investigated lakes was mirrored in shifts in microbial eukaryote community structure, which, however, was much less pronounced compared with interregional beta-diversity. Statistical analyses revealed that on a regional scale, environmental factors are strong predictors for plankton community structures in high-mountain lakes. While on long-distance scales (>10000km), isolation by distance is the most plausible scenario, on intermediate scales (up to 6000km), both contemporary environmental factors and historical contingencies interact to shift plankton community structures.

Livestock Grazing in Afromontane Grasslands in the Northern Bale Mountains, Ethiopia: Implications for Bird Conservation

Livestock Grazing in Afromontane Grasslands in the Northern Bale Mountains, Ethiopia: Implications for Bird Conservation

A new large species of Bitis Gray, 1842 (Serpentes: Viperidae) from the Bale Mountains of Ethiopia.

A new species of viperine viperid snake is described, Bitis harenna sp. nov. The new species is a member of the subgenus Macrocerastes based on it having three scales separating the nasal and rostral shields, and on the combination of 'divisions' of dorsal scale rows on the upper flanks and 'fusions' of rows on the lower flanks. Bitis harenna sp. nov. is distinguished from other members of the subgenus by its unique colour pattern, posterior parietal flange on the lateral wall of the braincase, and possibly by differences in scalation and head proportions. Only a single museum specimen is known, a female collected from 'Dodola' in Ethiopia probably in the late 1960s and previously identified as a possibly unusually coloured and patterned B. parviocula. A live, presumably male, specimen very closely resembling the holotype of Bitis harenna sp. nov. was photographed on the Harenna escarpment of the Bale Mountains National Park, Ethiopia in 2013, providing secure occurrence data and evidence that the holotype is not a uniquely aberrant specimen. A revised key to the species of Bitis in Ethiopia is presented. Aspects of body scalation are compared among species of the subgenus Macrocerastes and between species of Macrocerastes and Bitis, and several systematic characters are highlighted and clarified.

Interspecific association in ungulates of the Bale Mountains National Park, Ethiopia

AbstractThe aim of the study was to determine the frequencies of interspecific association formation and species preferences among five ungulates [bohor reedbuck (Redunca redunca), common warthog (Phacochoerus africanus), grey duiker (Sylvicapra grimmia), Menelik's bushbuck (Tragelaphus scriptus meneliki) and mountain nyala (Tragelaphus buxtoni)] in the northern Bale Mountains National Park, Ethiopia. Data were collected in three forest patches and in open grassland using total count technique in 2009 and 2011. The total number of ungulate groups found in interspecific associations was 444, comprising 26.8% of the total 1657 groups recorded. For the five study species, the relative frequency with which a given species occurred in interspecific association deviated significantly from the expected mean relative frequency (i.e. 26.8%). Each study species showed preferences to form interspecific associations with one or two other species. Interspecific association formation increased mean group sizes for bohor reedbuck and mountain nyala. And most of the species had greater overall mean group sizes in the open habitat compared to forest habitat. In general, the association pattern reported here could be attributed to antipredator response and/or mutual grazing facilitation, which might be beneficial to one or all of the species involved.

Institutional Arrangements and Management of Environmental Resources in Ethiopia

<p class="1Body">The study was conducted in three main eco-regions, namely Bale Mountains, South-West and Semien Eco-Regions in Ethiopia with the following objectives - to: (i) review the current institutional arrangements in terms of rights and responsibilities, planning system, capacity, and motivation of local communities for the management of environmental resources in Ethiopia in general, and the forest sector in particular and (ii) assess constraints for the successful implementation of policies/legislation, strategies, programs, projects and actions at a landscape level. Focus group discussion and semi-structured questionnaires were used to collect data. Purposive sampling method was employed to select respondents. Environmental resources conservation and management (ERCM) institutions considered in this study were agriculture and natural resources, water, irrigation and electricity, land and environmental protection, local administration, and road authorities. Within the above-mentioned institutions a total of 56 questionnaires were administered and 48 interviews were conducted. The results show that the capacity of the existing institutions is constrained by lack of clear rights and responsibilities, absence of common result framework, absence of common planning system, high staff turnover, absence of spatial planners and failure to respond to the demands of community-based organizations. The institutional arrangements need critical review and analyses in order to design responsible institutions for ERCM at all levels, which includes availing knowledgeable and all-rounded professionals at all levels, with proper incentive mechanisms, who would be able to cope with future challenges emanating from climate change and other social tensions.</p>

Phylogenetic position of a monotypic Ethiopian endemic rodent genus Megadendromus (Rodentia, Nesomyidae)

AbstractThe taxonomic and phylogenetic position of the Nikolaus’s African climbing mouse (

Laboratory Based Surveillance of Rabies Incidence in Ethiopian Wolf at Bale National Park, Ethiopia

In the Bale National Park s of Ethiopia, an estimated population of 250 wolves of greater than one year age exists, according to Ethiopian Wolf Conservation Authority (EWCA) pack observation done in 2010. A new outbreak of Ethiopian Wolf was observed between July 2015 and September, 2015 at Bale Mountains National Park. A collaborative investigation between Ethiopian Public Health Institute (EPHI) and Ethiopian Wild Life Conservation Authority (EWCA) was signed to undertake laboratory based surveillance of the dead wolves. Based on the MoU, field visits were made to collect and test rabies suspected samples for the presence of Lyssavirus antigens using the direct flouresent antibody test (FAT). Five samples collected for Lyssavirus diagnostic testing, demonstrated a positive result for the presence of Lyssavirus antigen whereas four samples revealed negative results using the direct flouresent antibody test. The rabies outbreak toll reached to fifteen wolves, of which nine samples were laboratory confirmed, and other six wolves were as epi-linked to the rabies laboratory confirmation result. Suspected dog rabies cases in and around the park was also observed some months before the outbreak occurred. The prevalence of wolf rabies in July was 2/250 (0.008), whereas it was 3/250 (0.012) in August, 2015. The death report of 4/250 (0.016) Ethiopian Wolf was registered as negative dFAT result in September, 2015. The other 6/250 (0.024) death cases were not submitted for laboratory confirmation. Human exposures occurred between these two months was zero. Mass vaccination of wildlife with oral vaccine is underway intensively to prevent non outbreak packs of the animals in the park to maintain the herd immunity level of the wolf population. Further molecular detection of the evolutionary history of wolf rabies in domestic dogs in and around the park and other wild animals’ rabies reservoirs should be undertaken.

Habitat use of ungulates in Bale Mountains National Park, Ethiopia

This study was conducted to determine habitat use, distribution and diversity of five ungulate species in the Bale Mountains National Park. Habitat use by each ungulate species was assessed using a total count method in 11 vegetation types between August and October 2009. Results showed the ungulates had wide and uneven distribution except for mountain nyala (Tragelaphus buxtoni) that mainly recorded in Adellay and Dinsho hill open lands. This nyala occupied all of the habitats, while Menelik's bushbuck (Tragelaphus scriptus meneliki) occupied nine habitats. Most species pairs had significant positive correlations regarding habitat use and preferences. Computed similarity index revealed the presence of considerable overlap in habitat among the ungulates (between 28% and 74%). The ungulates' habitat-use diversity index was 0.57–0.85, and mountain nyala had the highest and Menelik's bushbuck the lowest and the most habitat selective species. However, species known to be grazers had lower overlaps among themselves than between them and browsers, and vice versa reflecting a strategy used to avoid competition in some wildlife. The study provides useful information about ungulates and their habitats in the area. However, future research that focus on their feeding behaviour is needed to enhance our understanding of the ungulates relationships with their habitat.

Influence of topographic aspect on floristic diversity, structure and treeline of afromontane cloud forests in the Bale Mountains, Ethiopia

We studied the influence of east and west aspects on floristic composition, diversity, structure and treeline of afromontane cloud forests at Rira in the Bale Mountains, southeast Ethiopia. In addition, we studied how aspect relates to and/or interacts with other topographic and edaphic factors in influencing vegetation diversity. Stratified systematic plot sampling was used to survey the floristic composition, diversity and structure of forests on east- and west-facing slopes. The sample plot size was 20 × 20 m and a total of 36 plots were inventoried. A total of 72 composite soil samples were collected and analysed. Woody species richness of the forest on the east-facing slope was 1.7 times higher than on the west-facing slope. Shannon, Simpson and Log-series alpha diversity indices and evenness of forests on the east-facing slope were significantly higher than on the west-facing slope. NMDS ordination indicated that the east- and west-facing slopes formed two clusters of species and aspect explained 55.2 % and 10.4 % of the variation in species richness and abundance, respectively. There was no significant difference between aspects in stand structure except in dominant height, which was higher on the east-facing slopes. There was significant interaction between aspect and elevation in influencing woody species diversity. The four plant community groups, which were identified using cluster and indicator species analysis were represented differently on the east and west aspects. The treeline on the east-facing slope (3352 m) was located about 110 m higher than on the west-facing slope (3240 m). Soil moisture deficiency was unlikely to be a limiting factor on either site. Near the equator, east–west aspect was shown to have considerable impact on floristic composition, diversity, structure, and treeline position of montane forests. Diurnal cloud movement patterns and its impact on microclimate of slope aspect should be taken into account in future studies of cloud forest diversity, structure, and treeline position.

Correction: Unveiling Undercover Cropland Inside Forests Using Landscape Variables: A Supplement to Remote Sensing Image Classification

The worldwide demand for food has been increasing due to the rapidly growing global population, and agricultural lands have increased in extent to produce more food crops. The pattern of cropland varies among different regions depending on the traditional knowledge of farmers and availability of uncultivated land. Satellite images can be used to map cropland in open areas but have limitations for detecting undergrowth inside forests. Classification results are often biased and need to be supplemented with field observations. Undercover cropland inside forests in the Bale Mountains of Ethiopia was assessed using field observed percentage cover of land use/land cover classes, and topographic and location parameters. The most influential factors were identified using Boosted Regression Trees and used to map undercover cropland area. Elevation, slope, easterly aspect, distance to settlements, and distance to national park were found to be the most influential factors determining undercover cropland area. When there is very high demand for growing food crops, constrained under restricted rights for clearing forest, cultivation could take place within forests as an undercover. Further research on the impact of undercover cropland on ecosystem services and challenges in sustainable management is thus essential.

Phylogeography of Haplocarpha rueppelii (Asteraceae) suggests a potential geographic barrier for plant dispersal and gene flow in East Africa

East Africa is a biodiversity hotspot. Haplocarpha rueppelii (Sch.Bip.) Beauverd is mainly distributed in the alpine grassland of East Africa. Here we sampled 65 individuals of eight populations/locations of H. rueppelii including hairy and glabrous forms from Mts. Elgon, Aberdare, Kenya, Kilimanjaro and Bale Mountains. We then sequenced one nuclear and three chloroplast DNA fragments and conducted phylogeographic analyses to test the taxonomic rank of the two forms and causes for the differentiation (intrinsic reproductive isolation and geographic barrier). The results demonstrate that the species consists of two major groups, one includes the populations from Mts. Elgon, Aberdare and Bale, while the other includes Mts. Kenya and Kilimanjaro. The species has established in Mts. Kenya and Aberdare during the Pleistocene. However, migration rate for individuals between the two mountains was low as showed by gene flow analysis. A barrier for plant dispersal and gene flow would have existed between Mts. Aberdare and Kenya since at least Pleistocene. No change of the taxonomic concept of this species is needed. This study reveals a potential geographic barrier in East Africa. We hope it will arouse more scientists’ interests in phylogeography and biodiversity of East Africa.

Unveiling Undercover Cropland Inside Forests Using Landscape Variables: A Supplement to Remote Sensing Image Classification.

The worldwide demand for food has been increasing due to the rapidly growing global population, and agricultural lands have increased in extent to produce more food crops. The pattern of cropland varies among different regions depending on the traditional knowledge of farmers and availability of uncultivated land. Satellite images can be used to map cropland in open areas but have limitations for detecting undergrowth inside forests. Classification results are often biased and need to be supplemented with field observations. Undercover cropland inside forests in the Bale Mountains of Ethiopia was assessed using field observed percentage cover of land use/land cover classes, and topographic and location parameters. The most influential factors were identified using Boosted Regression Trees and used to map undercover cropland area. Elevation, slope, easterly aspect, distance to settlements, and distance to national park were found to be the most influential factors determining undercover cropland area. When there is very high demand for growing food crops, constrained under restricted rights for clearing forest, cultivation could take place within forests as an undercover. Further research on the impact of undercover cropland on ecosystem services and challenges in sustainable management is thus essential.

Canine distemper in endangered Ethiopian wolves.

The Ethiopian wolf (Canis simensis) is the world's rarest canid; ≈500 wolves remain. The largest population is found within the Bale Mountains National Park (BMNP) in southeastern Ethiopia, where conservation efforts have demonstrated the negative effect of rabies virus on wolf populations. We describe previously unreported infections with canine distemper virus (CDV) among these wolves during 2005-2006 and 2010. Death rates ranged from 43% to 68% in affected subpopulations and were higher for subadult than adult wolves (83%-87% vs. 34%-39%). The 2010 CDV outbreak started 20 months after a rabies outbreak, before the population had fully recovered, and led to the eradication of several focal packs in BMNP's Web Valley. The combined effect of rabies and CDV increases the chance of pack extinction, exacerbating the typically slow recovery of wolf populations, and represents a key extinction threat to populations of this highly endangered carnivore.

Assessment of Threat Status in the Northern Woodlands of the Bale Mountains, Ethiopia: Indicator for Management Effectiveness

The present study was carried out to identify the types and quantify the magnitude of human disturbances in six forest patches in the northern Bale Mountains, southeast Ethiopia. The principal objective was to compare three protected forest patches within the Bale Mountains National Park with three unprotected patches outside the park in terms of the severity of human-induced disturbances. Data was collected along five 1-km long transects in each patch. Eight major disturbance types were identified and quantified in the six forest patches: settlement, agriculture, selective logging, livestock herbivory, fuel wood collection, charcoal production, path/track formation and forest-fire. Results showed some degree of human disturbances in all patches, with logging, fuel wood collection, path/track formation and livestock grazing being the most widespread. Crop production, settlement and charcoal making, however, were only recorded in unprotected patches. Sixty percent and 47% of transects in these patches showed crop cultivation and houses respectively, covering 40% ha-1. The unprotected patches were characterized by significantly higher level of incidences of logged trees, fuel wood collection and livestock herbivory compared to the protected patches. For tree logging, this difference was however only observed for trees logged in recent years (estimated to be logged < 20 years) with logging of larger trees (DBH > 10 cm) than smaller trees. Generally the protected areas had reduced human disturbance as indicated by low logging activity. This is a positive indicator of effective management practices in the protected area. Key Words: Bale Mountains, Disturbance, Logging, Management effectiveness, Threat

Quaternary glacial and periglacial processes in the Ethiopian Highlands in relation to the current afro-alpine vegetation

Summary. The highlands of Ethiopia show a great variety in present and past climate. The environments differ in altitude, latitude and local conditions. This has an influence on vegetation and geomorphologic processes. Present knowledge of past glacial and periglacial landforms concentrates around the highest mountain ranges of Ethiopia, the Semien Mountains, the Bale Mountains and the Arsi Mountains. Many intermediate mountains stay unexplored or just briefly discussed. No present glaciated mountains exist in Ethiopia but current periglacial processes occur on the highest peaks. The climate change sensitivity of the mountain environment can be assessed which can contribute to the study of the temperature sensitive treeline and land cover changes. Afro-alpine vegetation can be influenced by the presence of relict (peri)glacial landforms, which change the growing conditions by different soil properties. Further research will need to complement the existing observations by unexplored mountains and to establish altitudinal north-south trajects in Ethiopia regarding vegetation, geomorphological processes and landforms.