Afromontane Research Articles

Population and conservation status of the endangered Dracaena ombet tree in dry Afromontane forests

Dracaena ombet, a flagship tree species in arid ecosystems, holds a significant ecological, economic, and socio-cultural value. However, its persistence is currently under threat from both anthropogenic and natural factors. Consequently, the species has been listed as an endangered tree species on the IUCN Red List, requiring urgent conservation actions for its continued existence. To develop effective conservation actions, it is necessary to have information on the population dynamics of the species. A study was conducted in the lowland and midland agroecological zones (sites) within the Desa'a dry Afromontane forest, northern Ethiopia to analyze the population status of D. ombet and identify its site-specific threats. At each site, abundance, health status, diameter, height and threats of the species were collected using 60 sample plots (20 m × 20 m) distributed over six transects (500 m × 20 m) spaced one km apart. The study showed that the D. ombet population was characterized by low abundance and unstable structure. It was further characterized by a substantial number of unhealthy damaged and dead trees. The low abundance of the species with unstable age structure in the dry Afromontane forests can be attributed to various factors such as stem cutting and debarking, leaf defoliation, overgrazing, soil erosion, and competition from expansive shrubs. Alternative livelihood options for the local inhabitants should be introduced to minimize the overexploitation of D. ombet for subsistence use in the dry Afromontane forests. The impacts of overgrazing and soil erosion on D. ombet and its Desa'a habitats should also be addressed through the introduction of community-based exclosures and in-situ soil and water conservation practices, respectively.

Species composition, relative abundance, and habitat association of birds in Dodola dry evergreen afro-montane forest and sub-afro-alpine scrubland vegetation, southeast Ethiopia.

Birds' functional groups are useful for maintaining fundamental ecological processes, ecosystem services, and economic benefits. Negative consequences of loss of functional groups are substantial. Birds are usually found at a high trophic level in food webs and are relatively sensitive to environmental change. The first surveillance bird study was carried out southeast of Ethiopia adjacent to Bale Mountain National Park aimed at investigating the composition, relative abundance, and distribution of Aves. Using regular systematic point transact sampling, the density and species composition were analyzed through the mark recapture distance sampling engine assisted by R statistical software. This study recorded a total of seventy-eight bird species over two distinct seasons. Among these, fifteen species were exclusive to Erica habitats, twenty-six were found in natural forest habitats, and three were specific to plantation forest habitats. The study also discovered three endemic species. Based on the 2018 IUCN Red List categories, six of the species are globally threatened, three are near threatened, and the remaining sixty-nine are classified as least concern. The relative abundance of birds did not significantly differ across habitats and seasons, but variations were observed among blocks. Bird density was found to fluctuate across the three habitats and two seasons; however, these habitat differences were not influenced by seasonal changes. The findings of this study reveal that the differences in composition and relative abundance are not merely seasonal changes in the forest and Erica habitats. Instead, these habitats create microclimates that cater to specific bird species. However, this localized endemism also presents challenges. The concentration of endemic species and potential resource constraints could pose a threat to these habitat-specialist birds.

Species-specific allometric models for reducing uncertainty in estimating above ground biomass at Moist Evergreen Afromontane Forest of Ethiopia

An allometric equation is used to convert easily measured tree variables into biomass. However, limited species-specific biomass equations are available for native tree species grown in various biomes of Ethiopia. The available pantropic generic equation has resulted in biases owing to the uncertainty of the generic model estimation due to the difference in tree nature and response to growth conditions. The objective of the study is, thus, to develop a species-specific allometric equation for reducing uncertainty in biomass estimation at the Moist Evergreen Afromontane Forest in south-central Ethiopia. Five tree species were selected for model development, these selected trees were harvested and weighed in the field. The measured above-ground biomass data related to easily measured tree variables: diameter at stump height, diameter at breast height (dbh), crown diameter, and total tree height. The developed model evaluated and compared with previously published model by using measures of goodness of fit such as coefficient of determination (R2), total relative error, mean prediction error, root mean square error, and Akaike information criteria. The analysis showed that a model with dbh as a single predictor variable was selected as the best model for the estimation of above-ground biomass. It gives the highest R2 for Syzygium guineense (0.992) and the lowest for Bersama abyssinica (0.879). The additions of other tree variables did not improve the model The pantropic model by Brown overestimates the biomass by 9.6–77.8% while both Chave models resulted in an estimation error of 12–50.3%. Our findings indicated that species-specific allometric equations outperformed both site-specific and pantropic models in estimating above-ground biomass by giving 0.1% up to 7.9% estimation error for the respective tree species.

Afromontane forests and human impact after the African Humid Period: wood charcoal from the Sodicho rock shelter, SW Ethiopian highlands

The SW highlands of Ethiopia are a key component in the evolution of modern humans. Yet, palaeoecological studies, essential to understand past human-vegetation relationships, are almost inexistent in this region. In this paper, we present an anthracological study of the Sodicho rock shelter, located at 1,930 m a.s.l. in the SW Ethiopian Afromontane forest zone, reconstructing the past woody vegetation since the end of the African Humid Period (ca. 5,000 cal bp). Our results show that the vegetation around the rock shelter from ca. 4,750 to 1,750 cal bp was an ecotone between Afromontane forest and wooded grasslands of the lowlands, maintained open by the use of fire, although the climatic conditions were favourable for closed forest. The charcoal assemblage also demonstrates strong wood selection, with Syzygium guineense, Acacia and Proteaceae as the preferred taxa, even during a volcanic event when human occupation had been assumed to be absent. We therefore suggest that the rock shelter might have been visited more continuously than previously thought. Finally, under less intense occupation activities from ca. 1,700 to 300 cal bp, forest taxa became comparatively more dominant than before, as documented in the charcoal record. This demonstrates that the forest can recover under reduced human impact. The fact that the Afromontane forest is resilient is of utmost importance, indicating that reforestation is still possible despite the strong agricultural and demographic pressures the Ethiopian highlands are currently facing.

Predictive Role of Species Diversity on Aboveground Carbon via Functional Diversity and Dominance in the Moist Afromontane Forest: Implications for Conservation Policies

Predictive Role of Species Diversity on Aboveground Carbon via Functional Diversity and Dominance in the Moist Afromontane Forest: Implications for Conservation Policies

Vegetation Structure and Regeneration Status of Woody Species in Gerba Dima Moist Afromontane Forest of Southwestern Ethiopia: Implications for Conservation

This study assessed vegetation structure and regeneration status of woody species in Gerba Dima forest, southwestern Ethiopia. Ninety sample plots measuring 25 m × 25 m were laid through a stratified random sampling procedure. The studied forest was stratified into three forest strata based on its altitudinal variation. Stratum I was found at an altitudinal range of 1500−1800 m, while strata II and III were located at altitudinal ranges of 1801−2000 m and 2001−2300 m, respectively. All woody plant species with a diameter at breast height (dbh) equal to or larger than 2.5 cm and a height of at least 1.5 m were recorded. Analysis of the structure of the vegetation was conducted using frequency distribution of dbh, height, and importance value (IV). The regeneration pattern of the study species was assessed by employing the total count of seedlings and saplings. The density of woody species in the study area was 1829 individuals ha−1. Basal area of the Gerba Dima forest was 65.05 m2ha−1. Total densities of seedlings, saplings, and trees/shrubs were 4558 ha−1, 2149 ha−1, and 1515 ha−1, respectively. Structural analysis and assessment of the regeneration status of woody species in the Gerba Dima forest showed that the overall ecological condition of the forest was healthy as indicated by inverse J‐curve dbh distribution, which showed a large number of individuals in lower dbh classes. Furthermore, a large number of seedlings and saplings were recorded for most species, in addition to the presence of a sufficient number of matured trees. However, some species exhibited abnormal population structure and abnormal patterns of regeneration characterized by fewer or no individuals in lower dbh, as well as in seedling and sapling stages. It was thus concluded that species with abnormal population structure and regeneration status (e.g., Sapium ellipticum and Trichilia dregeana) require urgent conservation attention.

Assessing vegetation cover and valuing ecosystem services in southwestern Ethiopia: Implications for conservation.

The Bench-Sheko zone, parts of the Eastern Afromontane Biodiversity Hotspot, is characterized by its rich biodiversity. However, recent reductions in vegetation cover have drawn concern, highlighting the critical role of remote sensing in monitoring these alterations is critical. Furthermore, this study evaluates the economic value of the ecosystem services rendered by the diverse types of vegetation cover class in the area. The classification of vegetation types and measuring their ecosystem benefits are crucial for monitoring vegetation and analyzing land cover changes. estimating the value of ecosystem services is vital for environmental impact assessments, cost-benefit analyses, and creating payment schemes for these natural services. For the vegetation cover map, it uses Sentinel-2 satellite data and a Random Forest classifier using Google Earth Engine. Based on a properly chosen reference, ecosystem service assessment approaches include benefit transfer, direct market value, and the social cost of carbon. The results highlight the vegetation classes' enormous value and the services they offer. The largest value for Supporting Services (2829.3 USD ha⁻1yr⁻1) is found in the Remnant Forest, which makes up 30.98% of the total area. With the highest value for both cultural services (2847.7 USD ha⁻1yr⁻1) and regulatory services (5063.9 USD ha⁻1yr⁻1), the wetlands, which make up 4.35% of the total area, stand out. The total annual value of all ecosystem services provided by all vegetation classes is estimated to be 2.089 billion USD. When paired with methods for tracking and assessing changes in vegetation cover over time, high-resolution satellite images and precise classification algorithms can offer insightful information on the condition of the environment and support informed decision-making. In order to evaluate and convey to society and policymakers the advantages of vegetation cover, the value of ecosystem services is essential.

Seed removal and fate of Carapa oreophila Kenfack (Meliaceae) across time and habitat in an Afromontane forest landscape

Seed removal and fate of Carapa oreophila Kenfack (Meliaceae) across time and habitat in an Afromontane forest landscape

The role of Dodola Community Conservation Area for large mammal conservation, Ethiopia

The role of community conservation areas for large mammals is rarely evaluated. We investigated the species richness and frequency of sightings of large mammals in the Dodola Community Conservation Area. The study area was stratified into three habitat types, and 49 lines transect was laid (27 Dry evergreen Afromontane forests, 20 Sub-afro-alpine habitats, and 2 plantation forests) based on the topography, land use, and vegetation cover of the study area. A total of 24 species of large mammals were identified and recorded in the study area. Though the community conservation area is home to diverse species of mammals, including some endemic and endangered ones such as mountain nyala and Bale Monkey, human encroachment, agriculture, and overgrazing are prominent in the area, putting huge pressure on flora and fauna. Therefore, we recommend the participatory approach be strengthened to ensure sustainable coexistence between people and wildlife.

Thermophilisation of Afromontane forest stands demonstrated in an elevation gradient experiment

Abstract. The response of tropical trees and tree communities to climate change is crucial for the carbon storage and biodiversity of the terrestrial biosphere. Trees in tropical montane rain forests (TMFs) are considered particularly vulnerable to climate change, but this hypothesis remains poorly evaluated due to data scarcity. To reduce the knowledge gap in the response of TMF trees to warming, we established a field experiment along a 1300–2400 m elevation gradient as a proxy for warming in Rwanda. Seedling-size trees of 20 species native to montane forests in eastern and central Africa were planted in multi-species plots at three sites along the gradient. They have overlapping distributions but primarily occur in either transitional rain forests (∼ 1600–2000 ma.s.l.) or mid-elevation TMFs (∼ 2000–3000 ma.s.l.), with both early- (ES) and late-successional (LS) species represented in each elevation origin group. Tree growth (diameter and height) and survival were monitored regularly over 2 years. We found that ES species, especially from lower elevations, grew faster at warmer sites, while several of the LS species, especially from higher elevations, did not respond or grew slower. Moreover, a warmer climate increased tree mortality in LS species, but not much in ES species. ES species with transitional rain forest origin strongly increased proportional to stand basal area at warmer sites, while TMF species declined, suggesting that lower-elevation ES species will have an advantage over higher-elevation species in a warming climate. The risk of higher-elevation and LS species of becoming outcompeted by lower-elevation and ES species due to a thermophilisation response in a warmer climate has important implications for biodiversity and carbon storage of Afromontane forests.

The coffee leaf rust pandemic: An ever‐present danger to coffee production

AbstractCoffee leaf rust (CLR) is caused by the biotrophic pathogenic fungus Hemileia vastatrix. Despite being the most researched coffee disease, mysteries still exist relating to its epidemiology and biology. The objective of this work is to highlight past and present events concerning this prominent coffee disease. We start with an historical overview of the homeland of Coffea arabica, the Afromontane forest of south‐west Ethiopia, and then follow its journey across the globe linked to colonial trade and power struggles. We report the relevance of CLR to coffee production today, with a focus on the Americas and summarize unproven hypotheses in relation to the cause of recent epidemics. We present an original hypothesis concerning the first major outbreak occurring in 1869 in Ceylon (Sri Lanka), based on geopolitical connections to global trade. We review old and new options for management of the disease. The likelihood of a yet undetected alternate host of H. vastatrix is also considered as an additional piece of the epidemiological puzzle. Finally, we reflect on the interactions between H. vastatrix and a changing climate. By better understanding past events, linked to CLR, we may be better prepared for future outbreaks.

The impact of land cover change on the carbon stock of moist afromontane forests in the Majang Forest Biosphere Reserve

BackgorundForest plays an important role in the global carbon cycle by sequestering carbon dioxide and thereby mitigating climate change. In this study, an attempt was made to investigate the effects of land use/land cover (LULC) change (1989–2017) on carbon stock and its economic values in tropical moist Afromontane forests of the Majang Forest Biosphere Reserve (MFBR), south-west Ethiopia. Systematic sampling was conducted to collect biomass and soil data from 140 plots in MFBR. The soil data were collected from grassland and farmland. InVEST modelling was employed to investigate the spatial and temporal distribution of carbon stocks. Global Voluntary Market Price (GVMP) and Tropical Economics of Ecosystems and Biodiversity (TEEB) analysis was performed to estimate economic values (EV) of carbon stock dynamics. Correlation and regression analyses were also employed to identify the relationship between environmental and anthropogenic impacts on carbon stocks.ResultsThe results indicated that the above-ground carbon and soil organic carbon stocks were higher than the other remaining carbon pools in MFBR. The mean carbon stock (32.59 M tonne) in 2017 was lower than in 1989 (34.76 Mt) of MFBR. Similarly, the EV of carbon stock in 2017 was lower than in 1989. Elevation, slope, and harvesting index are important environmental and disturbance factors resulting in major differences in carbon stock among study sites in MFBR.ConclusionsTherefore, the gradual reduction of carbon stocks in connection with LULC change calls for urgent attention to implement successful conservation and sustainable use of forest resources in biosphere reserves.

Ecological determinants in plant community structure across dry afromontane forest patches of Northwestern Ethiopia

Ethiopia is a mountainous country with great geographic diversity. The diversified topographic features in Ethiopia made the country have a rich biodiversity forest cover in tropical Africa. This made Ethiopia have the largest floral diversity in tropical Africa. This floral diversity is rich in endemic elements. About 6,027 vascular plant species (including subspecies) with about 10.7% endemism have been documented. Plant community types are primarily influenced by topographic factors, as well as disturbance and environmental factors. The objective of this study is to demonstrate that 1: The forest patches in the study area exhibit distinct plant community types. 2: The composition and structure of these plant communities are influenced by various environmental variables. To achieve this, a total of 76 plots were used to collect vegetation and environmental data. The collected data were then analyzed using the R software, employing agglomerative hierarchical cluster analysis and redundancy analysis (RDA) to identify plant communities and assess the relationship between these communities and environmental variables.R software was used to identify plant communities and analyze the relationship between plant community types and environmental variables using agglomerative hierarchical cluster analysis and redundancy analysis (RDA). Four plant community types were identified. The RDA results highlighted the significant impact (p < 0.005) of altitude, aspect, slope, grazing, and human interference on species distribution and the formation of plant communities. The RDA results highlighted the significant impact (p < 0.005) of altitude, aspect, slope, grazing, and human interference on species distribution and the formation of plant communities.The findings indicate that the variation in plant communities is closely associated with topographic factors such as altitude, slope, aspect, as well as disturbance factors like grazing, and human interference, with altitude being the most influential factor. Based on these findings, it is recommended that conservation plans take into consideration the effects of grazing and human interference in order to address the challenges faced in conserving forest patches in the future.Additionally, further research efforts should focus on mitigating disturbance factors and understanding the environmental variables that affect forest patches to enhance their conservation.

Effects of environmental changes on vegetation and soil characteristics at Lewi Afromontane forest and wetland in Northwestern Ethiopia.

Due to anthropogenic pressures, Ethiopian Afromontane forests, particularly Lewi Mountain and Wetland, are threatened and require urgent restoration planning and implementation. However, there is a lack of scientific baseline information to provide efficient restoration planning and implementation. Thus, this scientific research is being conducted to evaluate the condition of the vegetation and soil properties, specific to environmental variability in the study area. The study area was stratified as a natural forest patch, plantation stands, and wetland, and transect lines were established at a distance of 200m across the elevation. The 0.04-ha plots were established at transects with a distance of 200m. The biophysical and environmental data were collected and analyzed at each plot using descriptive and inferential statistics. The vegetation and soil parameters of natural forest patches, slopes, aspects, and elevation gradients vary considerably (p 0.029). The natural forest patches, gentle slopes, lower elevations, and northeast-facing gradients had the largest species diversity (1.7-2.4) and carbon stock (1105.9 tons ha-1). At the natural forest patch, there was significant human and livestock disturbance (3) and sporadic vegetation cover (< 50%). Natural forest patches and plantation stands had the best textural proportion, organic carbon (2.5-2.63%), total nitrogen (0.22-0.23%), available phosphorus (27.9ppm), and available potassium (11.3-12.9ppm). The study discovered that the soil and vegetation state at Lewi Mountain and the wetland fluctuated in response to environmental changes, necessitating restoration design and implementation tailored to environmental variability. This data is critical as a foundation for local, national, and international ecological restoration agents.

Responses of soil and water-related ecosystem services to landscape dynamics in the eastern Afromontane biodiversity Hotspot

The investigation of soil and water-related ecosystem services (ES) and recognizing the spatiotemporal effects of land-use and land cover changes (LULC) are essential for the formulation of conservation strategies. The research employed the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and the Revised Universal Soil Loss Equation (RUSLE) models for the assessment of ES. The study was carried out in the Kaffa Forest Biosphere Reserve in Ethiopia, which is part of the eastern Afromontane biodiversity hotspots. The aim of this investigation was to examine and map the temporal and spatial fluctuations in sediment retention, soil erosion, and water yield resulting from LULC modifications between 1986 and 2019, and to provide forecasts for the next three decades. According to the RUSLE analysis, the landscapes exhibited estimated soil losses ranging from zero to 1.5 tons ha-1 yr-1 in 1986, 2009, and 2019, respectively. The mean annual sediment exports for the years 1986, 1999, and 2019 were estimated to be 12.6, 9.9-, and 28.7-tons ha−1, respectively. The water yield of the site experienced a notable increase from 9.8 × 109 m3 in 1986 to 19.6 × 10 9 m3 in 1999, and subsequently rose to 39.3 × 109 m3 in 2019, which is considered to be a disadvantageous to the site. The study found a significant positive correlation between water yield and the expansion of settlement area (r = 0.99, P = 0.015) as well as agricultural land (r = 0.99, P = 0.05). It was also found that significant positive correlation found between vegetation dense area such as forest (r < 0.999, P < 0.001) and shrub & bamboo (r = 0.998, P = 0.036) with sediment retention service. The investigation discovered that there existed tradeoffs between the ES of sediment retention and water yield as the slope increased. The results may be attributed to the presence of dense vegetation cover on the elevated slope regions, rendering them unsuitable for agricultural activities, and the concurrent expansion of arable lands in the lower slope areas, which are flat terrains more conducive to cultivation. The transition from land with more vegetation density to land with lower or no vegetation coverage resulted in an increase in soil loss and water yield, while simultaneously decreasing the sediment retention service. Therefore, the findings can be used as a document to guide decision-makers to design soil-water conservation technologies to enhance the ecological integrity of the biosphere reserve.

Vegetation density and altitude determine the supply of dry Afromontane forest ecosystem services: Evidence from Ethiopia

Mapping forest ecosystem services (ES) and identifying both natural and anthropogenic factors influencing their supply and distribution is a key step for sustainable and climate-smart forest management planning. This is particularly important for dry and mountain forests which are among the most threatened and neglected ecosystems globally. These forests are facing increasing demands for different land uses and ES with rising conflicts with each other.This study identifies, quantifies, and maps the spatial distribution of one supporting, three regulating, and four provisioning forest ES. Furthermore, a set of potential natural and anthropogenic factors influencing ES distribution in Desa’a forest, a dry Afromontane Forest in Tigray, Ethiopia, was assessed. The supply of some of the assessed ES depended on vegetation density, while the supply of others depended on woody species diversity, which resulted in a clustering of ES in two different geographical areas. Both natural and anthropogenic factors were important for explaining variations in the spatial distribution of ES, of which altitude and vegetation density were the most influential factors.Our findings can contribute to the development of sustainable forest management strategies for dry and mountain forests by providing knowledge on the spatial supply of ES. The ES maps can be used as a basis for developing dedicated zoning plans which could improve forest management.

Isotopic insights into the Early Acheulean (1.95 Ma–1.66 Ma) high-elevation paleoenvironments at Melka Kunture (Upper Awash Valley, Ethiopia)

In this paper, we present stable carbon and oxygen isotope analyses of fauna tooth enamel from Garba IVD (1.95 Ma) and Gombore IB (1.66 Ma), two Early Acheulean sites of Melka Kunture (Upper Awash, Ethiopia), and discuss faunal taxonomy and fossil pollen. Our aim is to infer the diet and habitat of the fossil fauna, as well as the environment of both sites, in order to provide a broader paleoecological reconstruction. During the Pleistocene, the vegetation of the highlands of Ethiopia belonged to the Dry evergreen Afromontane Forest and grassland complex, which is distinct from the savanna of lower elevations in eastern Africa. Our carbon isotopic results indicate that all the analyzed faunal taxa were grazers consuming C4 plants, whereas oxygen isotopic results discriminate the taxa according to their semiaquatic or terrestrial habitats. These results are consistent with the taxonomic composition of the faunal assemblages and the palynological results, suggesting extended mountain grasslands in the landscape at Garba IVD. In contrast, the carbon isotopic results do not totally agree with the pollen paleoenvironmental reconstruction at Gombore IB, where the open vegetation was interrupted by forests and bushy vegetation. Stable isotope and pollen data provide different outcomes (feeding strategies vs. nearby plants) and have different temporal and spatial resolutions. This is relevant when reconstructing past environments by using independent proxies. Furthermore, isotopic comparisons with other Early Pleistocene paleontological and archaeological sites from eastern Africa indicate that all the analyzed taxa in common fed on C4 plants and that their dietary strategies were not affected by variations linked to the difference in elevations.

Parvapila lyncispinnae new genus and new species (Coleoptera, Melandryidae) from South Africa

The first Orchesiini of South Africa, Parvapila lyncispinnaegen. nov. and sp. nov., is described. Specimens were collected at the foot of the Langeberg Range and of the Kogelberg, mountains of Western Cape. Individuals were collected by sifting soil litter in Afromontane forests, an endemic vegetation community of Afrotropical mountainous areas.

Functional diversity along disturbance and environmental gradients in Ethiopian moist Afromontane forest

Considering multiple measures to fully capture functional diversity is important. However, the effects of disturbance gradients on diversity have been controversial, as species diversity alone may not fully capture these effects. This study aimed to evaluate trait-based diversity across disturbance gradients in the moist Afromontane forest of Ethiopia, Yayu Coffee Forest Biosphere Reserve (YCFBR). Vegetation data and relevant traits related to plant-life strategies, competition, and responses to disturbances were collected. A multiple regression model was used to test the response of functional diversity to disturbances and environmental gradients. The results revealed functional diversity in plant communities, including dendrogram-based functional diversity for plot-based (FDp), functional richness (FRic), functional evenness (FEve), functional divergence (FDiv), functional dispersions (FDis), and community-weighted mean of maximum tree height (CWM.Hmax), showed decreasing patterns with increasing disturbance intensity in the YCFBR. Additionally, the findings highlighted that FDis and Hmax are the most vulnerable functional traits to anthropogenic factors and are less tolerant in disturbed ecosystem environments. Therefore, reducing disturbances is crucial to maintaining higher levels of these functional diversities. For example, the results showed that the CWM.Hmax declined from 27.25 m to 15 m, indicating a shift towards shorter plant species. In contrast, the community-weighted mean of woody density (CWM.WD), the community-weighted mean of specific leaf area (CWM.SLA), and the community-weighted mean of seed mass (CWM.SM) increased significantly with an increase in disturbance intensity. For instance, CWM.SM and CWM.SLA changed from 5 to 14.25 (g) and 90 to 130 (cm2/g), respectively. These indices may serve as indicators of ecosystem resilience at disturbed forest ecosystem sites. Furthermore, the regression results indicated that FDp, FRic, FEve, FDiv, FDis, CWM.WD, and CWM.Hmax showed increasing patterns with increasing species richness, which suggests that protecting and promoting species diversity can contribute to maintaining high levels of functional diversity. The mixed effects model revealed that anthropogenic disturbance and elevational gradients had significant effects on functional diversity in the YCFBR. Therefore, when managing and conserving biodiversity in heterogeneous environments, both anthropogenic factors and environmental variables need to be considered. Species with low SLA and SM are recommended for the restoration of disturbed ecosystems. Overall, this study demonstrates that trait-based functional diversity is useful for predicting the adaptation potentials of species in heterogeneous environments and disturbance gradients.

14,000 years of climatic and anthropogenic change in the Afromontane forest of São Tomé Island, Gulf of Guinea

São Tomé (Gulf of Guinea, Central Africa) is a 854 km2 tropical island that had a pivotal role in early European colonial expansion through the Atlantic between the 15th and 16th centuries. Historical sources suggest that native vegetation has been heavily impacted since human arrival (1470 CE) due to monoculture economies and the introduction of mammals and plants, some of which now have established wild populations. The Afromontane forest of São Tomé, located above 800 m.a.sl., is particularly rich in endemic plant species and has remained relatively unaffected by direct human impacts. Here, we explore how environmental change influenced this forest through the study of a sedimentary sequence from the volcanic crater of Lagoa Amélia (1340 m a.s.l.), a palustrine system located at the boundary between submontane (800–1400 m a.s.l.) and mist forest (above 1400 m a.s.l.). We used fossil pollen, non-pollen palynomorphs, sedimentology and charcoal to determine forest dynamics from the Late Pleistocene to the present. From 14,000 to 12,500 cal yr BP the forest was dominated by taxa from higher altitudes, adapted to cooler and drier climates (e.g. Afrocarpus mannii trees and Psychotria nubicola). After 12,500 cal yr BP, a potential uphill migration was identified by an increase in taxa like the trees Symphonia globulifera and Craterispermum cerinanthum. From 11,200 cal yr BP through the rest of the Holocene taxa from lower altitudes became dominant (e.g. Prunus africana, Polyscias, and Sabicea), except at c. 8500 cal yr BP when rapid cooling led to forest opening. Charcoal showed that fires were frequent during the Late Pleistocene (14,000 to 11,200 cal yr BP), becoming rare during the Holocene until anthropogenic fires started at c. 220 cal yr BP. Other recent anthropogenic impacts detected in Lagoa Amélia included the appearance of pollen of introduced plant species (e.g., Cestrum), and the increase in pollen of economically important species (Elaeis guineensis, Zea mays) and in fungal spores related to introduced herbivores. Our results reveal that climate changed the altitudinal distribution of the Afromontane forest in São Tomé during the Late Pleistocene, as observed on the African continent, and that this ecosystem was also strongly impacted by human arrival, through fire, farming, and introduced species.