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    Hermann Taedoumg

    Thermal sensitivity of tropical trees A key uncertainty in climate change models is the thermal sensitivity of tropical forests and how this value might influence carbon fluxes. Sullivan et al. measured carbon stocks and fluxes in... more
    Thermal sensitivity of tropical trees A key uncertainty in climate change models is the thermal sensitivity of tropical forests and how this value might influence carbon fluxes. Sullivan et al. measured carbon stocks and fluxes in permanent forest plots distributed globally. This synthesis of plot networks across climatic and biogeographic gradients shows that forest thermal sensitivity is dominated by high daytime temperatures. This extreme condition depresses growth rates and shortens the time that carbon resides in the ecosystem by killing trees under hot, dry conditions. The effect of temperature is worse above 32°C, and a greater magnitude of climate change thus risks greater loss of tropical forest carbon stocks. Nevertheless, forest carbon stocks are likely to remain higher under moderate climate change if they are protected from direct impacts such as clearance, logging, or fires. Science , this issue p. 869
    Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these... more
    Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable ...
    Research Interests:
    Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the... more
    Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. We sampled all trees (diameter in breast height [dbh]≥10 cm) within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450-800 m apart). Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographic...
    ABSTRACT Background - The inventory of Cameroon's flora is far from complete and additional work is needed to document the country's extremely rich flora, and thus enhance its conservation. In this framework, botanical... more
    ABSTRACT Background - The inventory of Cameroon's flora is far from complete and additional work is needed to document the country's extremely rich flora, and thus enhance its conservation. In this framework, botanical exploration was conducted between 2007 and 2011 in various regions of Cameroon and resulted in the discovery of several new national records and new species. Methods - Normal practices of herbarium taxonomy have been applied. For the endemic or subendemic species, a preliminary IUCN conservation has been proposed using the IUCN criteria. Results - A total of twelve taxa are recorded as new for the flora of Cameroon. Significant range extensions are reported for eight restricted-range species. A new species, Psychotria yaoundensis O.Lachenaud, endemic to Cameroon and only know from two rocky hills in the surroundings of Yaounde, is described and illustrated. Additions to the flora of Equatorial Guinea (five species), Nigeria, Ivory Coast and the Democratic Republic of Congo (one species each) are also reported. Psychotria moliwensis and Vangueriopsis gossweileri are synonymised under P fernandopoensis and V rubiginosa, respectively. Conclusion - Many areas within Cameroon remain botanically poorly explored. Our exploration highlights the importance of the Rumpi Hills, Tchabal Mbabo, and the rocky hills around Yaounde for plant conservation. Our data will help conservationists in determining areas highly valuable for conservation.
    We report above-ground biomass (AGB), basal area, stem density and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass... more
    We report above-ground biomass (AGB), basal area, stem density and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha −1 (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region attaining AGB values (429 Mg ha −1 ) similar to those of Bornean forests, and significantly greater than East or West African forests. AGB therefore appears generally higher in palaeo- compared with neotropical forests. However, mean stem density is low (426 ± 11 stems ha −1 greater than or equal to 100 mm diameter) compared with both Amazonian and Bornean forests (cf. approx. 600) and is the signature structural feature of African tropical forests. While spatial autocorrelation complicates analyses, AGB shows a positive relationship with rainfall in the driest nine months of the year, and an opposite association with the wettest three ...
    Abstract The influence of functional traits on floristic patterns remains poorly understood in tropical rain forests. This contribution explores whether patterns of endemism of plant species are influenced by their life form and mode of... more
    Abstract The influence of functional traits on floristic patterns remains poorly understood in tropical rain forests. This contribution explores whether patterns of endemism of plant species are influenced by their life form and mode of dispersal. We used a comprehensive ...