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A vast silvicultural experiment was set up in 1982 nearby the town of M'Baïki in the Central African Republic to monitor the recovery of tropical forests after disturbance. The M'Baïki experiment consists of ten 4-ha Permanent Sample Plots (PSPs) that were assigned to three silvicultural treatments in 1986 according to a random block design. In each plot, all trees with a girth at breast height greater than 30 cm were spatially located, numbered, measured, and determined botanically. Girth, mortality and newly recruited trees, were monitored almost annually over the 1982–2022 period with inventory campaigns for 35 years. The data were earlier used to fit growth and population models, to study the species composition dynamics, and the effect of silvicultural treatments on tree diversity and aboveground biomass. Here, we present new information on the forest stand structure dynamics and tree demography. The data released from this paper cover the three control plots and constitute a major contribution for further studies about the biodiversity of intact tropical forests.

Selective logging can impact tree composition and the long-term sustainability of forests. Studying the ecological consequences of logging practices is crucial for guiding forest management strategies aiming at maintaining ecological integrity and supporting landscape-level conservation goals. We investigated the consequences of very low-intensity selective logging in multiple tree life stages across a logged forest chronosequence in Gabon. We found that species composition differed between logged and unlogged forests at all life stages (seedlings, saplings, and adults), which were most pronounced in the understory of older forests (logged 10 years prior) compared to unlogged areas. However, logging explained a small portion of the variation in species composition (<3% alone, <8% in combination with habitat). For functional composition, we observed higher wood density in the understory of older logged forests than in unlogged forests. Light-demanding saplings and saplings with animal-dispersed seeds were more prevalent in older logged forests than in unlogged forests. Timber species were less prevalent as seedlings and adults but more prevalent as saplings in logged forests compared to unlogged forests. Our results suggest that very low-intensity logging does not negatively impact key ecosystem services like carbon storage and food availability for frugivores. However, reduced prevalence of timber species may impact logging sustainability. Our study indicates that, when considering best-case scenarios, selectively logged forests have the potential to support conservation goals by offering refugia for biodiversity and maintaining essential ecosystem services. Thus, these forests have the potential to complement protected areas and serve as a sustainable alternative to more intensive land use.

Aim: Successional changes in functional diversity provide insights into community assembly by indicating how species are filtered into local communities based on their traits. Here, we assess successional changes in taxonomic and functional richness, evenness and redundancy along gradients of climate, soil pH and forest cover. Location: Neotropics. Time period: Last 0–100 years. Major taxa studied: Trees. Methods: We used 22 forest chronosequence studies and 676 plots across the Neotropics to analyse successional changes in Hill's taxonomic and functional diversity of trees, and how these successional changes vary with continental-scale gradients in precipitation, soil pH and surrounding forest cover. Results: Taxonomic and functional richness and functional redundancy increased, while taxonomic and functional evenness decreased over time. Functional richness and evenness changed strongly when not accounting for taxonomic richness, but changed more weakly after statistically accounting for taxonomic richness, indicating that changes in functional diversity are largely driven by taxonomic richness. Nevertheless, the successional increases in functional richness when correcting for taxonomic richness may indicate that environmental heterogeneity and limiting similarity increase during succession. The taxonomically-independent successional decreases in functional evenness may indicate that stronger filtering and competition select for dominant species with similar trait values, while many rare species and traits are added to the community. Such filtering and competition may also lead to increased functional redundancy. The changes in taxonomically-independent functional diversity varied with resource availability and were stronger in harsh, resource-poor environments, but weak in benign, productive environments. Hence, in resource-poor environments, environmental filtering and facilitation are important, whereas in productive environments, weaker abiotic filtering allo

Secondary tropical forests play an increasingly important role in carbon budgets and biodiversity conservation. Understanding successional trajectories is therefore imperative for guiding forest restoration and climate change mitigation efforts. Forest succession is driven by the demographic strategies—combinations of growth, mortality and recruitment rates—of the tree species in the community. However, our understanding of demographic diversity in tropical tree species stems almost exclusively from old-growth forests. Here, we assembled demographic information from repeated forest inventories along chronosequences in two wet (Costa Rica, Panama) and two dry (Mexico) Neotropical forests to assess whether the ranges of demographic strategies present in a community shift across succession. We calculated demographic rates for >500 tree species while controlling for canopy status to compare demographic diversity (i.e., the ranges of demographic strategies) in early successional (0–30 years), late successional (30–120 years) and old-growth forests using two-dimensional hypervolumes of pairs of demographic rates. Ranges of demographic strategies largely overlapped across successional stages, and early successional stages already covered the full spectrum of demographic strategies found in old-growth forests. An exception was a group of species characterized by exceptionally high mortality rates that was confined to early successional stages in the two wet forests. The range of demographic strategies did not expand with succession. Our results suggest that studies of long-term forest monitoring plots in old-growth forests, from which most of our current understanding of demographic strategies of tropical tree species is derived, are surprisingly representative of demographic diversity in general, but do not replace the need for further studies in secondary forests.

La procédure officielle d'inventaire des ressources ligneuses pour les forêts communautaires camerounaises constitue un obstacle technique et financier majeur. Plusieurs études ont testé des démarches simplifiées mais sans jamais pouvoir proposer une alternative satisfaisante à la méthode standard d'inventaire, à savoir plus abordable financièrement et techniquement pour les populations locales, tout en étant statistiquement robuste. L'article récapitule la démarche et les résultats d'un inventaire forestier à dire d'acteurs, qui a été expérimenté dans une forêt communautaire de 4 800 ha, au couvert forestier dégradé. Cet inventaire repose sur cinq simplifications (1) les seules espèces inventoriées sont celles vendues sur le marché domestique ; (2) les arbres inventoriés sont ceux situés à une distance inférieure à deux kilomètres d'une piste ou d'une rivière d'évacuation ; (3) seuls les arbres ayant un diamètre supérieur ou égal au diamètre minimum d'exploitabilité sont relevés ; (4) l'inventaire n'est réalisé qu'avec les propriétaires coutumiers volontaires ; (5) leur droit de possession coutumière sur les arbres est reconnu. Cet inventaire à dire d'acteurs a permis de recenser 3 885 arbres pour un volume de 19 297 m3 dans la forêt communautaire. La quasi-totalité (93 %) de ces arbres sont situés en cacaoyères. La démarche est techniquement robuste puisque le taux de sondage est estimé au minimum à 35 %, et est donc largement supérieur à celui de l'inventaire forestier standard de 2 %. Cet inventaire est également économique puisque son coût revient à moins de 0,5 €/ha, c'est-à-dire moins de la moitié du coût d'un inventaire classique. Il est enfin socialement acceptable puisqu'il valorise les savoirs traditionnels et permet d'élaborer un mode d'exploitation des arbres favorable aux propriétaires coutumiers. Il incite ces derniers à la durabilité en leur permettant de devenir les principaux bénéficiaires de cette activité. Cette méthode paraît adaptée au contexte