23 research outputs found
From forest to farmland: Species richness patterns of trees and understorey plants along a gradient of forest conversion in southwestern Cameroon
No full textVegetation surveys were carried out at 24 sampling stations distributed over four land use types, namely near-primary forest, secondary forest, agroforestry systems and annual crop lands in the northeastern part of the Korup region, Cameroon, to assess the impact of forest conversion on trees and understorey plants. Tree species richness decreased significantly with increasing level of habitat modification, being highest and almost equal in secondary and near-primary forests. Understorey plant species richness was significantly higher in annual crop lands than in other land use types. The four land use types differed in tree and understorey plant species composition, the difference being smaller among natural forests. Tree and understorey plant density differed significantly between habitat types. Density was strongly correlated with species richness, both for trees and understorey plants. Five tree and 15 understorey plant species showed significant responses to habitat. A 90% average drop in tree basal area from forest to farmland was registered. Our findings support the view that agroforestry systems with natural shade trees can serve to protect many forest species, but that especially annual crop lands could be redesigned to improve biodiversity conservation in agricultural landscapes of tropical rainforest regions
From forest to farmland: Habitat effects on afrotropical forest bird diversity
No full textAlthough the Guinea-Congolian rain forest region is an important focal point for conservation in Africa, very little information is available on the effects of forest modification and land use on the region's biodiversity. We studied bird communities and vegetation characteristics in 24 sampling stations distributed over two near-natural forests (near-primary forest, secondary forest), and two land use types (agroforestry, annual cultures) in the lowlands of the Korup region, Cameroon. Repeated sampling was used to establish near-complete inventories of bird assemblages for each site. Despite a 90% average drop in tree basal area, from forest to farmland, overall bird species richness did not decrease significantly with increasing habitat modification. However, different groups of birds responded in different ways. Frugivorous and omnivorous bird species richness did not differ between habitats, whereas richness in granivorous, flower-visiting, and nonbreeding species was higher in land use systems compared to forests. In contrast, insectivorous birds, especially terrestrial and large arboreal foliage gleaning insectivores, and ant followers showed,a declining species richness from forest to farmland. Also, richness in species of those restricted to the Guinea-Congolian forest biome and of the family Pycnonotidae showed a pronounced decline with increasing habitat modification. Species richness of overall insectivores, terrestrial insectivores, large- and medium-sized arboreal foliage gleaners, ant followers, as well as pycnonotids and biome-restricted species, were strongly or even very strongly positively correlated with overstory tree density and, in most cases, also with basal area. In contrast, tree density and basal area were strongly negatively correlated with species richness of nonbreeding visitors and flower-visiting bird species. Species composition was most distinct between near-primary forest and annual culture sites, and the abundance of 23 out of 165 species was affected by habitat, suggesting considerable partitioning of habitat niches along the habitat gradient. Our results stress the importance of tree cover in tropical land use systems for the maintenance of resident forest bird populations and confirm that natural forest management is more beneficial for global bird conservation compared to other forms of forest exploitation, including agroforestry systems
Lactarius megalopterus, a new angiocarpous species from a tropical rainforest in Central Africa, shows adaptations to endozoochorous spore dispersal
No full textISSN:1617-416XISSN:1861-8952ISSN:1861-895
Endemism and geographic distribution of African Thismiaceae
No full textBackground 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
Diversity, above-ground biomass, and vegetation patterns in a tropical dry forest in Kimbi-Fungom National Park, Cameroon
No full textThis work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.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
A New Species of Cassipourea (Rhizophoraceae) from Western Cameroon
No full textVolume: 16Start Page: 61End Page: 6
Making forest data fair and open
No full textData 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.Fil: de Lima, Renato A. F.. Universidade de Sao Paulo; BrasilFil: Phillips, Oliver L.. University of Leeds; Reino UnidoFil: Duque, Alvaro. Universidad Nacional de Colombia; ColombiaFil: Tello, J. Sebastian. Missouri Botanical Garden; Estados UnidosFil: Davies, Stuart J.. Smithsonian Tropical Research Institute; PanamáFil: de Oliveira, Alexandre Adalardo. Universidade de Sao Paulo; BrasilFil: Muller, Sandra Cristina. Universidade Federal do Rio Grande do Sul; BrasilFil: Honorio Coronado, Euridice N.. Instituto de Investigaciones de la Amazonía Peruana; Perú. University of St. Andrews; Reino UnidoFil: Vilanova, Emilio. Wildlife Conservation Society; Estados Unidos. Universidad de Los Andes; VenezuelaFil: Cuni Sanchez, Aida. Norwegian University of Life Sciences; Noruega. University of York; Reino UnidoFil: Baker, Timothy R.. University of Leeds; Reino UnidoFil: Ryan, Casey M.. University of Edinburgh; Reino UnidoFil: Malizia, Agustina. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Lewis, Simon L.. Colegio Universitario de Londres; Reino Unido. University of Leeds; Reino UnidoFil: ter Steege, Hans. Naturalis Biodiversity Center; Países BajosFil: Ferreira, Joice. Embrapa Amazônia Oriental; BrasilFil: Marimon, Beatriz Schwantes. Universidade Do Estado de Mato Grosso (unemat);Fil: Luu, Hong Truong. Vietnam Academy Of Science And Technology; VietnamFil: Imani, Gerard. Université Officielle de Bukavu; República Democrática del CongoFil: Arroyo, Luzmila. Museo de Historia Natural Noel Kempff Mercado; Bolivia. Universidad Autónoma Gabriel René Moreno; BoliviaFil: Blundo, Cecilia Mabel. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Kenfack, David. Smithsonian Tropical Research Institute; PanamáFil: Sainge, Moses N.. University Of Sierra Leone; Sierra Leona. Institute Of International Education; Estados Unidos. Cape Peninsula University of Technology; SudáfricaFil: Sonké, Bonaventure. Université de Yaoundé I; CamerúnFil: Vásquez, Rodolfo. Jardin Botanico de Missouri; Per
Wild meat consumption in urban Sierra Leone during Coronavirus-19
No full textWild meat is associated with an increased zoonotic disease risk. In some West African countries, wild meat consumption declined as the result of official restrictions following Ebola outbreaks in 2013-2016 and was also affected by the current Coronavirus 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 sex on the types of wild meat eaten and reasons for their consumption. We found that more males than females consumed wild meat often, and in both sexes, taste was the main reason for eating wild meat. Age did not affect wild meat consumption among females. Evidence for changes in consumer behaviour in response to zoonotic disease risk was mixed. While some consumers avoided wild meat because of disease, nobody stated it was the primary reason for not eating wild meat, and monkeys (presumed higher zoonotic disease risk) were amongst the species cited as being consumed often. More work is needed to help identify the best pathway towards safe and sustainable consumption of wild meat in urban Sierra Leone
Diversification of myco-heterotrophic angiosperms: evidence from Burmanniaceae.
No full textBackground - 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 dramaticall
