African Forest Research Articles

World Bank Financing and Sustainable Management of Tropical Forests

ABSTRACT Tropical forests contribute to maintaining the global ecological balance and to climate regulation. In 2002, the World Bank adopted a revised Forest Strategy to harness the economic potential of tropical forests, reducing poverty and promoting sustainability. This paper conducts a comparative analysis of forest sector project allocations between 2002 and 2020 using the institution’s global project database. The research results confirm that the forest cover of tropical countries is not a priority for World Bank funding, thus contradicting the stated aims of this institution. Only US$ 4.33 billion was allocated to tropical forests between 2002 and 2020, representing 0.41% of the total resources managed. At a particular disadvantage, due to the limited support received, is the African forest, which experienced a decline of more than 10% in its forest cover between 2002 and 2020. The evidence reported in this study justifies the need to significantly increase funding, reinforcing the link between productive development and sustainable forest management. In order to combat deforestation and restore forest cover in low-income countries, the World Bank must extend project benefits to more tropical countries, tailor new mechanisms to local conditions, and make it a priority to facilitate access to financing and increase non-repayable aid.

Population trends of the Cape Parrot Poicephalus robustus in the Amatholes, Eastern Cape: trialling ground-based flock photography for demographic and health assessment

Globally, 60% of species in the order Psittaciformes are experiencing population declines. Understanding demographic and health trends in populations is vital for the prioritisation of limited conservation resources. The Cape Parrot Poicephalus robustus is a South African endemic forest species that is endangered by habitat degradation and Psittacine Beak and Feather Disease (PBFD). In the Amathole region of the Eastern Cape province, Cape Parrots gather in large numbers every autumn to feed at a particular orchard of Pecan trees Carya illinoinensis. This annual event is an opportunity for researchers to assess trends in a population that does not otherwise typically form large flocks. We used a novel, non-invasive method of flock photography analysis between 2017 and 2022 to assess the demographics and PBFD symptoms of the population. A mean of 439 ± SD 127 Cape Parrots visited the orchard on the peak day each year, with 1.2 males per female and 3 adults per juvenile overall. Proportions of juveniles fluctuated between extremes of 70% in 2019 and < 4% in 2020. PBFD symptoms increased markedly in the food-scarce year of 2019, with a gradual recovery seen in the years following. Roosting numbers were also tracked monthly from 2018 to 2022 to indicate local population fluctuations in the study area around Hogsback. An average of 112 ± SD 31 Cape Parrots roosted there, with roost counts notably higher from January to June, bolstered by newly-fledged juveniles prior to their dispersal. This study demonstrates the use of flock photographs as an effective, non-invasive tool to assess the demographics and health of an avian population.

Survey-based inference of continental African elephant decline

Long-term quantification of temporal species trends is fundamental to the assignment of conservation status, which in turn is critical for planning and targeting management interventions. However, monitoring effort and methodologies can change over the assessment period, resulting in heterogeneous data that are difficult to interpret. Here, we develop a hierarchical, random effects Bayesian model to estimate site-level trends in density of African elephants from geographically disparate survey data. The approach treats the density trend per site as a random effect and estimates a parametric distribution of these trends for each partitioning of the data. Data were available from 475 sites, in 37 countries, between 1964 and 2016 (a total of 1,325 surveys). We implemented the model separately and in combination for the African forest (Loxodonta cyclotis) and savannah (Loxodonta africana) elephant species, as well as by region. Inference from these distributions indicates a mean site-level decline for each species over the study period, with the average forest elephant decline estimated to be more than 90% compared to 70% for the savannah elephant. In combination, there has been a mean 77% decline across all sites; but in all models, substantial heterogeneity in trends was found, with stable to increasing trends more common in southern Africa. This work provides the most comprehensive assessment undertaken on the two African elephant species, illustrating the variability in their status across populations.

Why models underestimate West African tropical forest primary productivity

Tropical forests dominate terrestrial photosynthesis, yet there are major contradictions in our understanding due to a lack of field studies, especially outside the tropical Americas. A recent field study indicated that West African forests have among the highest forests gross primary productivity (GPP) yet observed, contradicting models that rank them lower than Amazonian forests. Here, we show possible reasons for this data-model mismatch. We found that biometric GPP measurements are on average 56.3% higher than multiple global GPP products at the study sites. The underestimation of GPP largely disappears when a standard photosynthesis model is informed by local field-measured values of (a) fractional absorbed photosynthetic radiation (fAPAR), and (b) photosynthetic traits. Remote sensing products systematically underestimate fAPAR (33.9% on average at study sites) due to cloud contamination issues. The study highlights the potential widespread underestimation of tropical forests GPP and carbon cycling and hints at the ways forward for model and input data improvement.

Do elephants really never forget? What we know about elephant memory and a call for further investigation.

Despite popular culture's promotion of the elephant's ability to "never forget," there is remarkably limited empirical research on the memory capacities of any living elephant species (Asian, Elephas maximus; African savanna, Loxodonta africana; African forest, Loxodonta cyclotis). A growing body of literature on elephant cognition and behavioral ecology has provided insight into the elephant's ability to behave flexibly in changing physical and social environments, but little direct evidence of how memory might relate to this flexibility exists. In this paper, we review and discuss the potential relationships between what we know about elephant cognition and behavior and the elephants' memory for the world around them as they navigate their physical, social, and spatial environments. We also discuss future directions for investigating elephant memory and implications for such research on elephant conservation and human-elephant conflict mitigation.

Museomics reveal origins of East African Pleophylla forest chafers and Miocene forest connectivity

Here we present a nearly complete species-level phylogeny including 23 of the 25 known species of the forest-dwelling herbivorous scarab chafer beetle genus Pleophylla (Coleoptera: Scarabaeidae: Sericinae), based on the analysis of 950 nuclear genes (metazoan-level universal single-copy orthologs; mzl-USCOs). DNA sequences were obtained from freshly collected, ethanol-preserved samples and from dried museum specimens by target enrichment or genome shotgun sequencing. Alignment completeness of mzl-USCOs newly obtained here by target DNA enrichment of ethanol samples were very heterogenous and lower (29–62 %) than in Dietz et al. (2023a), while that of sequences recovered from dried samples was even lower (∼19 %). Alignment completeness of the sequences obtained from low coverage shotgun sequencing was highest (∼92 %), although the average coverage was much lower than for the target enrichment samples. We used the resulting phylogeny to reconstruct the historical biogeography of the group. To estimate a time-calibrated tree, we combined the mzl-USCO data of Pleophylla with a nucleotide alignment from an available transcriptomic dataset of Scarabaeoidea and used two different sets of secondary calibration points. Despite the problems associated with the capture rate of mzl-USCO sequences from museum specimens, we were able to infer a well-resolved phylogeny of the genus Pleophylla that also provided reliable estimates of the phylogenetic position of species for which we had little sequence data. Our study clearly identified South Africa as the geographic origin of Pleophylla. Timing and biogeographic history confirm a persistent fragmentation of forests since the Eocene. The occurrence of only one long-distance dispersal event from southern Africa to the Eastern African Arc even during the Miocene highlights the limited dispersal possibilities for these forest-adapted chafers, which do not seem to have had important northerly range expansions along hypothetical forest corridors during the Pleistocene.

Mapping South Africa's canopy-forming kelp forests using low-cost, high-resolution Sentinel-2 imagery

Globally, kelp forests play a vital role in providing ecological, social and economic services. They contribute to the livelihoods and resilience of many coastal communities. To date, a gap exists in contemporary, comprehensive and consistent maps of South African kelp forests, since they were last mapped partially in 2006 by covering 900 km of South Africa's coastline. This study addresses this gap by producing a comprehensive remotely sensed high-resolution 2016 map of canopy forming coastal kelp forests. Using the 10m resolution Sentinel-2 A and B spectral bands 4 (RED) and 8 (NIR), an expert derived Normalized Difference Vegetation Index (NDVI) threshold was used to detect surface protruding kelp forests along 1300 km coastline. The results were validated with expert verification and using Google Earth, data from historic maps, remote sensing and biomass estimation of South African kelp resources. Our study demonstrates the aptitude of Sentinel-2 for detecting canopy-forming kelps at low cost along South Africa's west and south coast. We report the encountered drawbacks in mapping an expansive coastline with varied sea conditions including wave activity, tides and turbidity. Comprehensive ground validation, long-term monitoring sites and the use of time series datasets remain a gap towards improving the calibration of remote sensing methods and long-term monitoring of South African kelp forests. Our results provide a foundation for continuous monitoring of South African kelp forests as well as exploring other unmapped kelp/similar habitats to inform research and environmental management.

Divergent seed dispersal outcomes: Interactions between seed, disperser, and forest traits.

Animals disperse seeds in various ways that affect seed deposition sites and seed survival, ultimately shaping plant species distribution, community composition, and ecosystem structure. Some animal species can disperse seeds through multiple pathways (e.g., defecation, regurgitation, epizoochory), each likely producing distinct seed dispersal outcomes. We studied how seed traits (size and toughness) interact with disperser species to influence seed dispersal pathway and how this ultimately shapes the proportion of seeds deposited in various habitat types. We focused on three frugivorous species of duikers (African forest antelopes) in the Dja Faunal Reserve, a tropical rainforest in southern Cameroon. Duikers can both defecate and regurgitate seeds, the latter predominantly occurring during rumination at their bedding sites (or "nests"). We located duiker nests and dungs along 18 linear 1-km-transects to assess: (1) how seed traits affect the likelihood of dispersal via defecation versus regurgitation, (2) if defecated versus regurgitated seeds are deposited at different rates in different forest types (assessed by indigenous Baka), microhabitats, and forest structural attributes (measured by drone lidar), and (3) if these differ between three duiker species that vary in size and diel activity patterns. We found that duikers predominantly defecated small seeds (<3 mm length) and regurgitated larger and tougher seeds (>10 mm length), the latter including 25 different plant species. The three duiker species varied in their nesting habits, with nocturnal bay duikers (Cephalophus dorsalis) nesting in dense understory vegetation at proportions 3-4 times higher than Peter's and yellow-backed duikers (Cephalophus callipygus and Cephalophus silvicultor). As a result, bay duikers deposited larger regurgitated seeds at a higher rate in habitats with denser understory where lianas and palms predominate and near fallen trees. This directed regurgitation seed deposition likely plays an important and unique role in forest succession and structure. This study highlights the importance of ungulate seed dispersal by regurgitation, a vastly understudied process that could impact many ecosystems given the prevalence of ruminating ungulates worldwide.

Four new Afrotropic Hapsimachogonia (Lepidoptera, Lasiocampidae, Lasiocampinae, Argudini)

Four new species of the genus Hapsimachogonia Prozorov &amp; Zolotuhin, 2016 are described: 1) Hapsimachogonia graham sp. n. from Uganda; 2) Hapsimachogonia margit sp. n. from Angola and Namibia; 3) Hapsimachogonia max sp. n. from West African Sahel; and 4) Hapsimachogonia michael sp. n. predominantly occurring in West African forests but also recorded in a few locations northwards in the Sahel. Hapsimachogonia cavuata Prozorov &amp; Zolotuhin, 2016 is recorded for the first time in the Central African Republic. Adults of both sexes, their genitalia, map with collecting localities, and phylogenetic tree with p-distances are analyzed and illustrated.

Genetic resources of African mahogany in Brazil: genomic diversity and structure of forest plantations

BackgroundAfrican mahogany species (Khaya sp.) have been introduced to Brazil gaining increasing economic interest over the last years, as they produce high quality wood for industrial applications. To this date, however, the knowledge available on the genetic basis of African mahogany plantations in Brazil is limited, which has driven this study to examine the extent of genetic diversity and structure of three cultivated species (Khaya grandifoliola, Khaya senegalensis and Khaya ivorensis) and their prospects for forest breeding.ResultsIn total, 115 individuals were genotyped (48 of K. grandifoliola, 34 of K. senegalensis and 33 of K. ivorensis) for 3,330 filtered neutral loci obtained from genotyping-by-sequencing for the three species. The number of SNPs varied from 2,951 in K. ivorensis to 4,754 in K. senegalensis. Multiloci clustering, principal component analysis, Bayesian structure and network analyses showed a clear genetic separation among the three species. Structure analysis also showed internal structure within each species, highlighting genetic subgroups that could be sampled for selecting distinct genotypes for further breeding, although the genetic distances are moderate to low.ConclusionIn our study, SNP markers efficiently assessed the genomic diversity of African mahogany forest plantations in Brazil. Our genetic data clearly separated the three Khaya species. Moreover, pairwise estimates of genetic distances among individuals within each species showed considerable genetic divergence among individuals. By genotyping 115 pre-selected individuals with desirable growth traits, allowed us not only to recommend superior genotypes but also to identify genetically distinct individuals for use in breeding crosses.

Expanding forest carbon sinks to mitigate climate change in Africa

Forests significantly contribute to climate change mitigation by acting as carbon sinks, sequestering atmospheric carbon dioxide, and keeping it in soil and biomass. Covering 22 % of its land, African forests offer numerous benefits to millions of people. Nevertheless, they face threats from human activities like deforestation and degradation. A holistic approach encompassing social, economic, and environmental factors is necessary to sustain forests as carbon sinks for maximum carbon sequestration potential. This study used carbon dioxide emissions, forest loss and gain, and land use change to investigate the level of carbon dioxide emissions and their relationship to forest loss and climate change in Africa from 1992 to 2020. Using ArcGIS, land use change was reclassified, InVEST model calculated carbon storage and sequestration, and annual changes in forest cover were assessed using the K and S indices. In the last two decades, 77.36 % of African countries had greater forest losses than gains, leading to 32 × 103 kha net loss, resulting in 15.73 Pg C of carbon dioxide emissions. Annual forest loss rate is 1.6 × 103 kha, equivalent to 0.786 Pg C, and that of carbon storage and sequestration decreased to −0.69 and −1.37, respectively. Results indicate that deforestation, particularly in the Democratic Republic of the Congo, significantly contributes to carbon emissions, and persistent tropical deforestation will affect future greenhouse gas concentrations. This research provides a detailed spatiotemporal analysis, highlighting areas experiencing severe forest cover change and carbon loss, underscoring the importance of forest conservation in mitigating climate change, and promoting effective land management policies.

Deforestation amplifies climate change effects on warming and cloud level rise in African montane forests

Tropical montane forest ecosystems are pivotal for sustaining biodiversity and essential terrestrial ecosystem services, including the provision of high-quality fresh water. Nonetheless, the impact of montane deforestation and climate change on the capacity of forests to deliver ecosystem services is yet to be fully understood. In this study, we offer observational evidence demonstrating the response of air temperature and cloud base height to deforestation in African montane forests over the last two decades. Our findings reveal that approximately 18% (7.4 ± 0.5 million hectares) of Africa’s montane forests were lost between 2003 and 2022. This deforestation has led to a notable increase in maximum air temperature (1.37 ± 0.58 °C) and cloud base height (236 ± 87 metres), surpassing shifts attributed solely to climate change. Our results call for urgent attention to montane deforestation, as it poses serious threats to biodiversity, water supply, and ecosystem services in the tropics.

Human-De Brazza’s monkey conflict in Kafa Biosphere Reserve, Kafa Zone South West, Ethiopia

BackgroundHuman-wildlife conflict (HWC) is any interaction between humans and wildlife that arises when wildlife necessities encroach on those of the human population. It affects all areas where animal and peoples cohabit regardless of geography or climatic circumstances; but the burden is great in developing nations. De Brazza’s monkey (DM) (Cercopithecus neglectus) is one of the most unusual species in the group of Old-World monkeys commonly known as guenons. The De Brazza’s monkey is distributed in different parts of African forests from Guinea to Ethiopia. This study was conducted in Kafa Biosphere Reserve, Kafa Zone, South West Ethiopia, to assess the causes of human wildlife conflict in the area. The methods used were, household questionnaire, focus group discussion and direct field observation from June 2022 to May 2023.ResultsThe study revealed that the major causes of human De Brazza’s monkey conflicts were; habitat destruction 52.9%, (n = 72), human proximity to natural forest, 25.7%, (n = 35) and increasing of its population size 8.1 %, (n = 11). These monkeys’ raids crop usually early in the morning 42.6%, (n = 58), and late evening 29.4%, (n = 40). Maize was the most damaged crop by De Brazza’s monkey followed by coffee. The study also confirmed that guarding was the most common method used to protect crops from crop raiding wildlife in the area. Majority 66.2%, (n= 90) of the informants had negative attitude but 22.1%, (n = 30) had positive attitude towards De Brazza’s monkey conservation.ConclusionThe study discovered that, in contrast to olive baboons and grivet monkeys in the area, De Brazza's monkeys were not previously identified as crop raiders; however, they are currently causing damage to crops, especially maize and coffee crops. This could be due to habitat destruction and human proximity to the forest boundary. Thus, the conflict between humans and De Brazza's monkeys is escalating. As such, we recommended more research on the population status of the monkeys and strategies for coexist in the area.

Exploring the West African forest island phenomenon: scientific insights gained, successes achieved and capacities strengthened.

Anthropogenic activities around local villages in mesic savanna landscapes of West Africa have resulted in soil improvement and forest establishment outside their climatic zones. Such unique 'forest islands' have been reported to provide ecosystem services including biodiversity conservation. However, the science underpinning their formations is limitedly studied. In 2015 and with funding support from the Royal Society-DFID (now FCDO), we set out to investigate the biogeochemistry of the forest islands in comparison with adjacent natural savanna and farmlands across 11 locations in Burkina Faso, Ghana and Nigeria. Our results showed that the forest islands do not differ significantly from the adjoining ecosystems in soil mineralogy implying that their formation was anthropogenically driven. We observed greater soil organic carbon and nutrient distributions in the forest islands, which also had more stable macro (>500 μm) and meso-aggregates (500-250 μm) than the adjoining agricultural lands. We found that soil micro-aggregate (250-53 μm) stability was climate (precipitation) driven in the West African ecosystems while meso- and macro-aggregate stability was land-use driven. In one of the unique forest islands we studied in the Mole National Park of Ghana, we found its mineral-associated organic carbon over 40% greater than the adjoining natural savanna with potential implications for the achievement of the global initiative of the '4p1000' in West Africa. We conclude that the North-South-South research collaboration has established clearly, the science underlying the age-long West African forest island phenomenon and has, among many successes, led to capacity building of young scientists driving cutting-edge research in climate change adaptation and food systems transformation in the sub-region.

Traditional taboos: informal and invisible protection of remaining patches of forest in Vhembe District in Limpopo, South Africa

IntroductionSince 1990, there has been a global decline in forest areas. Between 2010 and 2020, the greatest annual net loss of forests was on the African continent. Despite South African indigenous forests and trees being protected under the National Forests Act of 1998 (Act No. 84 of 1998), the country has also shown an increased annual net loss of forests. Although the Vhembe District Municipality in South Africa has lost forest owing to human-induced deforestation and other land use activities, sacred forests have not been affected. According to traditional beliefs, exploitation of such indigenous patches of sacred forests is taboo. This study aims to explore the role of taboos in the protection of the remaining patches of sacred forest.MethodsThe study relies on data collected between December 2022 and December 2023. Semi-structured interviews were conducted with key informants (n = 61) and local communities in Tshidzivhe and Duthuni villages (n = 60). Observations were used as a further data collection tool. The interview questions were prepared to assess the role of taboos in the protection and management of sacred forests. Data collected through interviews were analysed using thematic content analysis, while field observations helped to corroborate the results from the interviews. Results and discussionThe study identified two main taboos – one that restricts entry into the sacred forests (i.e. preventing entry into the sacred forests, and harvesting, hunting and hiking in these areas), and another that prohibits noise or activities that disrespect sacred forests. The study found that believers and non-believers alike, for fear of retribution by the spirits, still obey these taboos and their related myths. This has allowed these areas to develop dense stands of closed-canopy evergreen forest that support more diverse flora and fauna than found in surrounding areas. Although sacred forests are not meant for biodiversity conservation, they offer opportunities to be integrated into global conservation targets of “30x30” and “Half-Earth” by 2030. They also offer the opportunity of serving as carbon sinks which is key to climate change mitigation. Recommendations for protecting sacred forests and associated taboos are drawn up based on these results.

Effects of habitat biotic features on hymenopteran diversity in East Africa

PurposeOriginally, the coastal region of East Africa was largely covered with coastal forest. With the human settlement, the majority of these forests have been transformed into agricultural land for subsistence farming. Today, only small and geographically isolated forest remnants exist and form a mosaic of different habitat types, including natural, semi-natural and anthropogenic ones. The forest remnants may still represent valuable habitats for typical forest plant and animal species.MethodsIn this study, we surveyed hymenopteran diversity and community composition in different habitat types in southern Kenya. Hereby we considered a small remnant of East African coastal forest, adjoining orchards, shrublands, tree plantations, agricultural fields, and settlements. Hymenoptera represent a large variety of taxa and provide relevant ecosystem services such as pollination to the local people. Hymenoptera were collected with coloured pan traps, identified to family or genus level, and sorted to morphospecies. Habitat parameters such as dead wood, leaf litter, vegetation structure, and the availability of flowers has been assessed for each study site.ResultsIn total, we found 419 Hymenoptera individuals of 153 morphospecies. The different habitat types showed distinct species communities of Hymenoptera. Increasing shrub layer and increasing herb cover had a negative effect on hymenopteran species richness and abundance. Flowers, trees, leave litter, and deadwood showed no significant effect on hymenopteran diversity.ConclusionOur results underline that small-scale habitat diversity lead to high overall diversity of Hymenoptera. Implications for insect conservation: The coastal forest remnant still holds a unique hymenopteran community with 20 Hymenoptera species exclusively found in this habitat type. It is thus of very high conservation value.

Arbuscular mycorrhizal fungal diversity and potential association networks among African tropical forest trees.

Tropical forests represent one of the most diverse and productive ecosystems on Earth. High productivity is sustained by efficient and rapid cycling of nutrients, which is in large part made possible by symbiotic associations between plants and mycorrhizal fungi. In these associations, an individual plant typically associates simultaneously with multiple fungi and the fungi associate with multiple plants, creating complex networks among fungi and plants. However, there are few studies that have investigated mycorrhizal fungal composition and diversity in tropical forest trees, particularly in Africa, or that assessed the structure of the network of associations among fungi and trees. In this study, we collected root and soil samples from Ise Forest Reserve (Southwest Nigeria) and used a metabarcoding approach to identify the dominant arbuscular mycorrhizal (AM) fungal taxa in the soil and associating with ten co-occurring tree species to assess variation in AM communities. Network analysis was used to elucidate the architecture of the network of associations between fungi and tree species. A total of 194 Operational Taxonomic Units (OTUs) belonging to six AM fungal families were identified, with 68% of all OTUs belonging to Glomeraceae. While AM fungal diversity did not differ among tree species, AM fungal community composition did. Network analyses showed that the network of associations was not significantly nested and showed a relatively low level of specialization (H2 = 0.43) and modularity (M = 0.44). We conclude that, although there were some differences in AM fungal community composition, the studied tree species associate with a large number of AM fungi. Similarly, most AM fungi had great host breadth and were detected in most tree species, thereby potentially working as interaction network hubs.

Solar Radiation Triggers the Bimodal Leaf Phenology of Central African Evergreen Broadleaved Forests

AbstractCentral African evergreen broadleaved forests around the equator exhibit a double annual cycle for canopy phenology and carbon uptake seasonality. The underlying drivers of this behavior are poorly understood and the double seasonality is not captured by land surface models (LSM). In this study, we developed a new leaf phenology module into the ORCHIDEE LSM (hereafter ORCHIDEE‐AFP), which utilizes short‐wave incoming radiation (SWd) as the main driver of leaf shedding and partial rejuvenation of the canopy, to simulate the double seasonality of central African forests. The ORCHIDEE‐AFP model has been evaluated by using field data from two forest sites and satellite observations of the enhanced vegetation index (EVI), which is a proxy of young leaf area index (LAIYoung) with leafage less than 6 months, as well as six products of GPP or GPP proxies. Results demonstrate that ORCHIDEE‐AFP successfully reproduces observed leaf turnover (R = 0.45) and young leaf abundance (R = 0.74), and greatly improve the representation of the bimodal leaf phenology. The proportion of grid cells with a significant positive correlation between the seasonality of modeled LAIYoung and observed EVI increased from 0.2% in the standard model to 27% in the new model. For photosynthesis, the proportions of grid cells with significant positive correlations between modeled and observed seasonality range from 26% to 65% across the six GPP evaluation products. The improved performance of the ORCHIDEE‐AFP model in simulating leaf phenology and photosynthesis of central African forests will allow a more accurate assessment of the impacts of climate change in tropical forests.

Environmental variation predicts patterns of genomic variation in an African tropical forest frog

Central African rainforests are predicted to be disproportionately affected by future climate change. How species will cope with these changes is unclear, but rapid environmental changes will likely impose strong selection pressures. Here we examined environmental drivers of genomic variation in the central African puddle frog (Phrynobatrachus auritus) to identify areas of elevated environmentally-associated turnover. We also compared current and future climate models to pinpoint areas of high genomic vulnerability where allele frequencies will have to shift the most in order to keep pace with future climate change. Neither physical landscape barriers nor the effects of past Pleistocene refugia influenced genomic differentiation. Alternatively, geographic distance and seasonal aspects of precipitation are the most important drivers of SNP allele frequency variation. Patterns of genomic differentiation coincided with key ecological gradients across the forest-savanna ecotone, montane areas, and a coastal to interior rainfall gradient. Areas of greatest vulnerability were found in the lower Sanaga basin, the southeastern region of Cameroon, and southwest Gabon. In contrast with past conservation efforts that have focused on hotspots of species richness or endemism, our findings highlight the importance of maintaining environmentally heterogeneous landscapes to preserve genomic variation and ongoing evolutionary processes in the face of climate change.

Integrative taxonomic revision of the African thicket rats (Murinae: Grammomys): how genomics decreases the number of currently recognized species

Abstract Thicket rats of the genus Grammomys are partly arboreal rodents distributed across a large part of sub-Saharan Africa. Previous work showed that their highest diversity is in forests and woodlands of Eastern Africa, that the evolutionary history of the genus roughly mirrors the evolution of African forests, and that the currently delimited species (names) do not correspond to major genetic clades. We used thousands of single nucleotide polymorphisms to perform phylogenomic analysis and to delimit genomic pools (i.e. candidate biological species). The resulting molecular operational taxonomic units were then compared with the most comprehensive sets of other available data (mitochondrial DNA variability, ecological requirements, morphology, karyotypes, sequences from the type material, etc.) and used for an integrative solution to the taxonomy of the genus. Our revision delimited seven species, which is less than the 12 recognized in the most recent literature on African rodents. We conclude that the African thicket rats represent a classic example of challenging problems in current integrative taxonomy. It is now relatively easy to obtain genomic data and to delimit candidate species, but it is much more complicated to give them species names using the valid rules of zoological nomenclature.