RESUMEN
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.
RESUMEN
PREMISE: The 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. METHODS: We 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. RESULTS: In 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. DISCUSSION: Data 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.
RESUMEN
BACKGROUND: Myco-heterotrophy evolved independently several times during angiosperm evolution. Although many species of myco-heterotrophic plants are highly endemic and long-distance dispersal seems unlikely, some genera are widely dispersed and have pantropical distributions, often with large disjunctions. Traditionally this has been interpreted as evidence for an old age of these taxa. However, due to their scarcity and highly reduced plastid genomes our understanding about the evolutionary histories of the angiosperm myco-heterotrophic groups is poor. RESULTS: We provide a hypothesis for the diversification of the myco-heterotrophic family Burmanniaceae. Phylogenetic inference, combined with biogeographical analyses, molecular divergence time estimates, and diversification analyses suggest that Burmanniaceae originated in West Gondwana and started to diversify during the Late Cretaceous. Diversification and migration of the species-rich pantropical genera Burmannia and Gymnosiphon display congruent patterns. Diversification began during the Eocene, when global temperatures peaked and tropical forests occurred at low latitudes. Simultaneous migration from the New to the Old World in Burmannia and Gymnosiphon occurred via boreotropical migration routes. Subsequent Oligocene cooling and breakup of boreotropical flora ended New-Old World migration and caused a gradual decrease in diversification rate in Burmanniaceae. CONCLUSION: Our results indicate that extant diversity and pantropical distribution of myco-heterotrophic Burmanniaceae is the result of diversification and boreotropical migration during the Eocene when tropical rain forest expanded dramatically.
