Despite the potential of secondary tropical forests to store and sequester substantial amounts of carbon, little is known about their above-ground carbon (AGC) stocks and the factors affecting them, especially in West Africa. This information is of key importance if the countries in this region want to achieve their forest restoration and climate mitigation commitments. To fill in this gap, we investigated how environmental and local management (e.g. remnant trees) factors influenced AGC and tree species richness in secondary forests at seven sites across Guinea, Sierra Leone and Liberia. We established 140 plots (20 x 50 m) in fallows <15 years (20 plots per site) and sampled all trees >= 10 cm diameter following standardised protocols. We found that AGC stocks and tree species richness increased with fallow age, but were highly variable across sites driven by both climatic and local management practices. While drought stress negatively affected AGC, remnant trees had a positive effect. AGC recovery rates ranged between 0.72 Mg C ha(-1) y(-1) (second driest site) and 13.76 Mg C ha(-1) y(-1) (wettest site). Given its low cost, our findings highlight the potential of passive restoration in secondary forests for carbon sequestration, particularly in wetter landscapes and areas with remnant trees from prior land use.

The submontane forests in the Congo Basin have not been studied sufficiently in terms of floristic diversity, biomass, and geographic distribution. The region's lack of resources and rugged terrain are among the barriers to sampling biodiversity. This study focuses on two understudied submontane forest areas, Bakossi National Park (BNP) and Mt. Nlonako (MN), which form part of the continental Cameroon Mountains and are believed to have high species diversity and endemism. However, significant gaps exist in biodiversity data across the continental Cameroon Mountains. This study is the first detailed quantitative survey of forests in the BNP and MN through permanent plot sampling. The results of this study can be used to guide policies for managing montane ecosystems in Cameroon and enhancing conservation efforts. The study also provides an opportunity for long-term monitoring of forest health and REDD+ status.

Changes in lunar illumination alter the balance of risks and opportunities for animals, influencing activity patterns and species interactions. We examined if and how terrestrial mammals respond to the lunar cycle in some of the darkest places: the floors of tropical forests. We analysed long-term camera trapping data on 86 mammal species from 17 protected forests on three continents. Conservative categorization of activity during the night revealed pronounced avoidance of moonlight (lunar phobia) in 12 species, compared with pronounced attraction to moonlight (lunar philia) in only three species. However, half of all species in our study responded to lunar phases, either changing how nocturnal they were, altering their overall level of activity, or both. Avoidance of full moon was more common, exhibited by 30% of all species compared with 20% of species that exhibited attraction. Nocturnal species, especially rodents, were over-represented among species that avoided full moon. Artiodactyla were more prominent among species attracted to full moon. Our findings indicate that lunar phases influence animal behaviour even beneath the forest canopy. Such impacts may be exacerbated in degraded and fragmented forests. Our study offers a baseline representing relatively intact and well-protected contexts together with an intuitive approach for detecting activity shifts in response to environmental change.

AbstractWild meat is associated with an increased risk of zoonotic diseases. In some West African countries wild meat consumption declined as the result of official restrictions following Ebola outbreaks during 2013–2016, and was also affected by the current Covid-19 pandemic. In Sierra Leone, a country affected by these diseases, we documented wild meat use in four markets in the capital, Freetown. From a total of 197 interviews, we analysed the influence of age and gender on the types of wild meat eaten and the reasons for their consumption. We found that more men than women consumed wild meat, and for both genders taste was the main reason for eating wild meat. Age did not affect wild meat consumption amongst women. Evidence for changes in consumer behaviour in response to zoonotic disease risk was mixed. Although some consumers avoided wild meat because of disease risk, none stated this was the primary reason for not eating wild meat, and monkeys (presumed to carry a high zoonotic disease risk) were amongst the species cited as being consumed often. More work is needed to identify the best pathway towards safe and sustainable consumption of wild meat in urban Sierra Leone.

Mangrove ecosystems remove carbon from the atmosphere and store it predominantly in soils constituting an important carbon sink. Additionally, they foster biodiversity and provide ecosystem services supporting local livelihoods and enhancing coastal protection. However, mangroves are declining in extent and experiencing degradation due to human activities as well as climate change impacts like sea-level rise and increasing frequency of extreme events. This study investigated how different levels of human-driven degradation affect forest structure, above- and belowground carbon stocks, tree species composition, and the population structures of dominant tree species. We investigated 19 transects of different degradation levels (pristine, moderately degraded, heavily degraded) in various locations (oceanic, riverine, interior) in the Sherbro river estuary in Sierra Leone. Results showed that total carbon stocks of pristine mangroves amounted to 707 Mg C ha(-1) including soils to 1 m depth, which is higher than carbon stocks reported from many other regions in Africa. Degradation resulted in declining basal area, decreasing density of large trees (>= 30 cm diameter) but increasing stem density of small trees (5-10 cm diameter). All carbon pools declined with increasing degradation across all locations. While above- and belowground carbon decreased by 96 %, soil carbon (up to 1 m depth) decreased by 44 %. Heavy degradation resulted in a change in the dominating species from Rhizophora racemosa to Rhizophora mangle across all locations. Overall, we found major effects of degradation on mangrove characteristics and minor effects of location. We urge conservation of pristine forests, restoration of degraded mangroves, and the establishment of management systems that are ecologically informed and based on a comprehensive understanding of human-driven degradation impacts.

Data on tropical forests are in high demand. But ground forest measurements are hard to sustain and the people who make them are extremely disadvantaged compared to those who use them. We propose a new approach to forest data that focuses on the needs of data originators, and ensures users and funders contribute properly.

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers. Examining drivers of the latitudinal biodiversity gradient in a global database of local tree species richness, the authors show that co-limitation by multiple environmental and anthropogenic factors causes steeper increases in richness with latitude in tropical versus temperate and boreal zones.

Tropical forests store 40–50 per cent of terrestrial vegetation carbon1. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests2. Owing to climatic and soil changes with increasing elevation3, AGC stocks are lower in tropical montane forests compared with lowland forests2. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane2,5,6 and lowland7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa8. We find that the low stem density and high abundance of large trees of African lowland forests4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse9,10 and carbon-rich ecosystems. The aboveground carbon stock of a montane African forest network is comparable to that of a lowland African forest network and two-thirds higher than default values for these montane forests.

Department of Environmental and Occupational Studies, Faculty of Applied Sciences, Cape Peninsula University of Technology, Cape Town Campus, Keizersgracht, P.O. Box 652, Cape Town 8000, South Africa Department of Horticultural Sciences, Faculty of Applied Sciences Cape Peninsula University of Technology, P.O Box 1906, Bellville 7535, South Africa Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045 USA Corresponding author’s email: Moses.sainge@gmail.com, mnsainge@tropegcam.org Tel: (+233) 556479170

Research highlights: This study is one of few detailed analyses of plant diversity and vegetation patterns in African dry forests. We established permanent plots to characterize plant diversity, above-ground biomass, and vegetation patterns in a tropical dry forest in Kimbi-Fungom National Park, Cameroon. Our results contribute to long-term monitoring, predictions, and management of dry forest ecosystems, which are often vulnerable to anthropogenic pressures. Background and objectives: Considerable consensus exists regarding the importance of dry forests in species diversity and carbon storage; however, the relationship between dry forest tree species composition, species richness, and carbon stock is not well established. Also, simple baseline data on plant diversity are scarce for many dry forest ecosystems. This study seeks to characterize floristic diversity, vegetation patterns, and tree diversity in permanent plots in a tropical dry forest in Northwestern Cameroon (Kimbi-Fungom National Park) for the first time. Materials and methods: We studied associations between above-ground biomass and species composition, and how different vegetation types vary in terms of species composition, diversity, and carbon storage, in a dry forest in Kimbi-Fungom National Park, Cameroon. Vegetation was inventoried in 17 permanent 1-ha plots. Allometric equations were used to calculate above-ground biomass and carbon. Results: We found an average of 269.8 tree stems ha−1 and 43.1 species ha−1. Five vegetation types: semi-deciduous, gallery, mixed vegetation, secondary and the grassland/woody savanna forest were classified using TWINSPAN analysis. The five vegetation types had an average above-ground biomass of 149.2 t ha−1 and 74.6 tC ha−1 of carbon in the 17 ha analyzed. Canonical correspondence analysis (CCA) showed the importance of semi-deciduous forest over grassland/woody savanna forest. Conclusions: This study demonstrated that the forest of the Kimbi-Fungom National Park is poor in plant diversity, biomass, and carbon, highlighting the need to implement efficient management practices. Fine-scale inventory data of species obtained in this study could be useful in developing predictive models for efficient management of tropical dry forests.

PremiseThe field of biodiversity informatics has developed rapidly in recent years, with broad availability of large‐scale information resources. However, online biodiversity information is biased spatially as a result of slow and uneven capture and digitization of existing data resources. The West African Plants Initiative approach to data capture is a prototype of a novel solution to the problems of the traditional model, in which the institutional “owner” of the specimens is responsible for digital capture of associated data.MethodsWe developed customized workflows for data capture in formats directly and permanently useful to the “owner” herbarium, and digitized significant numbers of new biodiversity records, adding to the information available for the plants of the region.ResultsIn all, 190,953 records of species in 1965 genera and 331 families were captured by mid‐2018. These data records covered 16 West African countries, with most of the records (10,000–99,999) from Côte d'Ivoire, Ghana, Togo, Nigeria, and Cameroon, and the fewest data records from Mauritania (<100 records). The West African Plants Initiative has increased available digital accessible knowledge records for West African plants by about 54%. Several of the project institutions have put initial project data online as part of their Global Biodiversity Information Facility data contributions. The average cost of data capture ranged from US$0.50−1.00 per herbarium sheet.DiscussionData capture has been cost‐effective because it is much less expensive than de novo field collections, allows for development of information resources even for regions in which political situations make contemporary field sampling impossible, and provides a historical baseline against which to compare newer data as they become available. This new paradigm in specimen digitization has considerable promise to accelerate and improve the process of generating high‐quality biodiversity information, and can be replicated and applied in many biodiversity‐rich, information‐poor regions to remedy the present massive gaps in information availability.

Tropical montane forests can store and sequester substantial amounts of carbon in above-ground biomass (AGB), but variations in this storage related to location or degradation have not been quantified in the Cameroon Highlands. We established 25 permanent plots (20 m x 40 m) and sampled all trees >= 10 cm diameter following standard RAINFOR protocols. We estimated AGB and investigated variations related to taxonomic and structural forest attributes, including the height-diameter allometry in five forest types (four old-growth dominated by different species and one secondary forest). Secondary forests had significantly lower AGB than old-growth forests (49.4 +/- 2.5 vs. >476.3 +/- 168.7 Mg/ha, respectively), mostly related to lower basal area and tree height. Significant differences in species composition but not in forest structure or AGB were found between the four types of old-growth forests studied, located at different altitudes and mountains. We discuss the importance of these montane forests for carbon storage and, considering their high diversity and current threats, their potential for carbon finance mechanisms related to both avoided deforestation and forest restoration.

Background: The Rumpi Hills Forest Reserve (RHFR) is a montane forest area in south-western Cameroon. Although RHFR is presumed to be rich in biodiversity and vegetation types, little information exists regarding its floristic composition and vegetation patterns.Objectives: Our goal was to characterise vegetation patterns in the reserve and to understand how elevation influences distributions and diversity of species. We aimed to provide a first detailed plant species inventory for this important forest area, as well as basic information on forest structure.Method: We characterised floristic composition and vegetation patterns of the reserve in 25 1-ha plots along an elevational gradient from 50 m to 1778 m. In each plot, trees and lianas of diameter at breast height (dbh) ≥ 10 cm were measured; shrubs 10 cm were measured in nested plots of 0.01 ha.Results: In all, 16 761 trees, shrubs and lianas with dbh ≥ 1 cm were censused, representing 71 families, 279 genera and 617 morphospecies. Floristic composition ranged from 94 to 132 species, with a mean of 117.5 species per hectare in lowland forest (50 m – 200 m) and 36–41 species, with a mean of 38.5 species per hectare in montane cloud forest (1600 m – 1778 m) near the summit of Mount Rata. Two-way indicator species analysis classified the 25 plots into six vegetation types corresponding to lowland evergreen rainforest, lowland evergreen rainforest on basalt rocks, middle-elevation evergreen forest, submontane forest, transitional submontane forest and montane cloud forest. In all, 0.006% of the reserve was included in our sample plots. Detrended correspondence analysis highlighted the importance of elevation in shaping vegetation patterns.Conclusion: The RHFR is composed of different vegetation types, which show impressive variation in terms of structure, species composition and diversity. The detailed, fine-scale inventory data obtained in this study could be useful in planning efficient management of this and other montane tropical forests.

Human culture has an important influence on how forests are utilised, yet its influence on ecosystem service (ES) use and valuation remains underexplored. We address this gap by investigating how livelihood strategy and ethnicity affect local peoples' perceptions of forest ES in Cameroon. Data were collected through 20 focus-group discussions in villages of farmers (Oku and Banso) and pastoralists (Fulani) in two mountains. Pastoralists identified fewer ES than farmers, and used some ES differently (e.g. wildlife was only valued for aesthetics instead of as food). Some differences were also observed between farmer groups (e.g. identity link with the forest unique to Oku farmers). While water availability was perceived as the most important forest ES for all groups, the second most important was fodder for pastoralists and medicine resources for farmers. Pastoralists also identified fewer useful forest species, most likely related to their origin in the lowlands. Our findings help highlight trade-offs in important ES for different groups (fodder vs. medicine resources), and in access to certain ES (e.g. Fulani pastoralists' unequitable access to tourism and forest income). We show that locals dependent on provisioning ES are not a homogenous group and that the wider socio-cultural context has to be taken into account for conservation and development projects to be successful.

Background and aims – Cola, the second largest genus of the Malvaceae-Sterculioideae comprises 100–135 small to large tree species confined in nature to African forests, though cultivated elsewhere. Current species distribution ranges show that the genus is highly diverse in the seasonally wet forests along the Nigeria-Cameroon border, including the Korup National Park (KNP). In this paper we examine the diversity and abundance of Cola in KNP compared to other forests for which comparable data are available. We also describe two novelties in the genus.Methods – We used inventory data from a 50-ha permanent plot in southern KNP where all Cola trees and saplings down to 1 cm in diameter were tagged, mapped and identified. Additional collections of the genus came from the 11 km trail leading to the plot. Classic herbarium techniques and field observations were used for the morphological identification and description of specimens at MO and YA and from our personal collections. Cola species richness and abundance was estimated from the plot data and compared to other African forest sites for which comparable data are available. The evaluation of the conservation status of the two new species described in this paper followed the IUCN Red List Categories and Criteria. Key results – Twenty-five species of Cola were identified in the southern part of the KNP, including four undescribed species, raising the total number of Cola species in Cameroon to 46. The abundance of the genus in KNP was three orders of magnitude higher than in the Rabi forest in southwestern Gabon or in the Ituri forest in eastern D.R. Congo. This high species richness and abundance suggests that KNP is part of the center of diversity of the genus. Two new species, Cola zemagoana Kenfack & D.W.Thomas and C. mamboana Kenfack & Sainge are described and illustrated. Both species are only known from the lowland rainforest of southwestern Cameroon. Cola zemagoana is narrow endemic of southern KNP and its conservation status is assessed as Endangered. Cola mamboana is confined to the lowland forests of southwestern Cameroon, is locally very abundant in protected areas and is also assigned the conservation status Endangered.

Background and aim The occurrence of the enigmatic plant family Thismiaceae has never been characterized in detail, but appears to be focused in three vegetation types. This study used data from the literature, in tandem with detailed new field data from Cameroon, to document, map, and predict potential distributions of Thismiaceae species across Africa, and relate their occurrence to features of climate. Methods - We reviewed known occurrences of Thismiaceae species across Africa; in Cameroon, Thismiaceae occurrences were studied in 22 1-ha plots (220 000 m(2)), at lowland, sub-montane, and montane sites in evergreen forest, semi-deciduous forest, and woody and grassland savannah vegetation types. Assembling known occurrences from across the continent, ecological niche modeling was used to map potential geographic ranges of African Thismiaceae under present-day climate conditions across Africa. Results and discussion - In Cameroon fieldwork, 338 individual Thismiaceae were recorded, corresponding to eleven species of Afrothismia. The most occupied vegetation type for Thismiaceae was sub-montane forest. Occurrence of Thismiaceae seems to depend principally on rainfall, as most specimens were recorded in areas with high rainfall, about six weeks after the first rains, toward the middle or end of the rainy season. This pattern seems to be consistent across all of the species. Soil analyses shows that Afrothismia was most frequent under conditions of low calcium (0.09-15.21 %) and pH of 3.58-6.16. Niche models predicted that additional Thismiaceae populations may be discovered at high-rainfall sub-montane forest sites in Democratic Republic of Congo, Rwanda, Tanzania, and Kenya. Across tropical Africa, the Thismiaceae comprise 22 species in two genera (twenty Afrothismia and two Oxygyne), recorded from seven countries. Many of these species are narrowly endemic to one or a few specific sites, so that detailed knowledge of distributional patterns is important for their conservation.

With the emergence of a new field, biodiversity informatics, an important task has been to evaluate completeness of biodiversity information that is existing and available for various countries and regions. This paper offers a first and very basic assessment of sampling gaps and inventory completeness across the Cameroon Mountains. Because digital accessible knowledge is severely limited for the region, we relied on qualitative evaluations of inventory completeness, supplemented by large amounts of data from the National Herbarium of Cameroon (YA) database. Detailed botanical inventories have been developed for Mt Cameroon, the Kupe-Mwanenguba Mountains, Mt Oku, and the Mambila Plateau, leaving substantial geographic and environmental coverage gaps corresponding to Rumpi Hills, Mt Nlonako, Kimbi Fungom National Park, Bali and Bafut Ngemba, Mt Bamboutos, Kagwene, and Tchabal Mbabo. This paper provides a roadmap for a comprehensive botanical survey for this region. Completing this survey plan, the resulting data will allow researchers to track changes in biodiversity and identify priority areas for conservation on the various mountain ranges that make up this important biodiversity hotspot.

The Neotropics, Afrotropics and Madagascar have different histories which have influenced their respective patterns of diversity. Based on current knowledge of these histories, we developed the following predictions about the phylogenetic structure and composition of rainforest tree communities: (Hypothesis 1) isolation of Gondwanan biotas generated differences in phylogenetic composition among biogeographical regions; (H2) major Cenozoic extinction events led to lack of phylogenetic structure in Afrotropical and Malagasy communities; (H3) greater angiosperm diversification in the Neotropics led to greater phylogenetic clustering there than elsewhere; (H4) phylogenetic overdispersion is expected near the Andes due to the co-occurrence of magnoliids tracking conserved habitat preferences and recently diversified eudicot lineages. Using abundance data of tropical rainforest tree species from 94 communities in the Neotropics, Afrotropics and Madagascar, we computed net relatedness index (NRI) to assess local phylogenetic structure, i.e. phylogenetic clustering vs. overdispersion relative to regional species pools, and principal coordinates of phylogenetic structure (PCPS) to assess variation in phylogenetic composition across communities. We observed significant differences in phylogenetic composition among biogeographical regions (agreement with H1). Overall phylogenetic structure did not differ among biogeographical regions, but results indicated variation from Andes to Amazon. We found widespread phylogenetic randomness in most Afrotropical and all Malagasy communities (agreement with H2). Most of central Amazonian communities were phylogenetically random, although some communities presented phylogenetic clustering (partial agreement with H3). We observed phylogenetic overdispersion near the Andes (agreement with H4). We were able to identify how differences in lineage composition are related to local phylogenetic co-occurrences across biogeographical regions that have been undergoing different climatic and orographic histories during the past 100 Myr. We observed imprints of the history following Gondwana breakup on phylobetadiversity and local phylogenetic structure of rainforest tree communities in the Neotropics, Afrotropics and Madagascar.

A new sequestrate Lactarius species was found in a humid evergreen tropical rainforest dominated by Fabaceae of the subfamily Caesalpinioideae in Cameroon, Central Africa. It is described here as new to science and is named Lactarius megalopterus, referring to its spore ornamentation of extraordinarily high wings. Anatomical characters and molecular systematic analyses confirm its relationship to Lactarius subgenus Plinthogali. Phylogenetic analyses based on two nuclear DNA regions revealed its close relationship to Lactarius angiocarpus, which is also an angiocarpous species from Zambia in Africa. Molecular studies have shown that tuber-like, sequestrate sporocarps evolved independently in several lineages of Basidiomycota. The findings of sequestrate fungi in tropical rainforests raise questions regarding the evolutionary benefit of enclosing the spore-producing hymenium. The enclosure of spore-producing tissue has often been associated with the protection of the delicate hymenium against desiccation in arid habitats or against frost in cold habitats. However, these cannot be the selective factors in warm and humid areas like the tropics. This controversy is exemplarily studied and discussed in the family of Russulaceae, especially in the genus Lactarius. Characters shown by the angiocarpous sporocarp of the new Lactarius, such as thick-walled statismospores, an aromatic smell and mild taste, can be interpreted as adaptations to endozoochorous spore dispersal by mammals. Therefore, here we prefer the alternative hypothesis that sequestrate sporocarps are the result of adaptation to endozoochorous spore dispersal.

Gambeya korupensis Ewango & Kenfack (Sapotaceae: Chrysophylloideae), a new rain forest tree species from the Southwest Region in Cameroon, is described and illustrated. A distribution map is provided. G. korupensis has the leaf blade below pubescent on the midribs and secondary nerves, flowers with a pedicel 0.5 – 1 mm long, and a fruit which is ovoid, attenuate at the apex, 5-ridged, verrucose between the ridges, and bright red at maturity. The conservation status of G. korupensis is assessed as Vulnerable according to IUCN criteria.