When considering all trees irrespective of their species, natural tropical rain forests typically exhibit spatial patterns that range from random to regular. The regularity is often interpreted as a footprint of tree competition. Using 23 permanent sample plots totalling 61 ha in the rain forests of central Africa, we characterized their spatial patterns and modelled those that exhibited regularity by a Strauss point process. This Strauss process is obtained as a Markov point process whose interaction function is an exponential function of a competition index commonly used in forestry. The parameter of this Strauss process characterizes the strength of competition. The 23 plots in central Africa differed in tree density and basal area, and could be discriminated depending on the type of spatial patterns: plots having a large basal area with respect to their density had a non regular pattern, whereas those having a small basal area with respect to their density had a regular pattern. For those plots that exhibited regularity, average tree size could be used to predict the strength of competition. The parameter of the Strauss process was significantly related to the average size by a linear relationship, such that competition decreases as average tree size increases. This relationship extrapolated to a null value of the Strauss parameter when average tree size reaches 32 cm in diameter. This relationship between average tree size and spatial pattern is a testable feature for future studies on the relationship between competition and spatial pattern in natural forests. (Résumé d'auteur

Rattans, one of the major non‐timber forest products used by the population in and around Kisangani (Democratic Republic of Congo), are a significant source of income and the basis of a very active informal sector focused towards supplying the city with raw canes. We present the effects of harvest and light availability on the demography of two common rattan species in the Yoko forest reserve, near Kisangani: Eremospatha haullevilleana De Wild. and Laccosperma secundiflorum (P. Beauv.) Küntze. We studied clump demography for a year, under variable light condition and harvesting regimes (control, partial harvest and complete harvest of adult stems). We show a positive effect of full and partial light availability on the dynamic of individuals for both species but with variable treatment responses. We also demonstrate that a partial harvest of two‐thirds of adults cane is beneficial or nondetrimental to the production of new shoots under partial or full‐light conditions. These results suggest opportunities for multiple‐use management that integrate timber and rattan harvesting in forest around Kisangani.

Cybocephalus nipponicus Endrödy-Younga 1971 is recorded for the first time in Romania. An up-to-date map of its distribution in Europe is presented, together with pictures of the male collected at ‘Dunele Marine de la Agigea’ nature reserve.

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