Evaluation of anatomical and physical properties of Khaya nthotheca (Welw.) C. DC. from forests of different altitudes in the democratic Republic of Congo

The anatomical and physical properties of Khaya anthotheca (Welw.) C. DC wood from the transition forest of middle altitude (zone 1) and the humid dense forest of low altitude (zone 2) in the East of the Democratic Republic of Congo were evaluated to ascertain the effect of growth area on the anatomical and physical properties. The heartwood vessels and rays number/mm2 varied significantly (P<0.001) between the two zones. The heartwood collected in zone 1 was significantly the richest (P<0.001) in vessel sand rays number. The average number of vessels and width of rays were higher in zone 2 and varied significantly (p < 0.0001) between the two zones.. Biotopes rays length was higher in zone 1 and varied significantly (p < 0.001) between the two zones. Nevertheless, the wood vessels distribution in the radial direction was homogeneous despite the zone; there was no significant difference in basic density, dry density and total volume shrinkage of K. anthotheca heartwood from the two zones..Keywords: Anatomy, vessel, rays, density, Khaya anthothec

La foresterie communautaire au Gabon : l'esprit de la loi

Les forêts communautaires constituent une des innovations sociales les plus importantes de la nouvelle loi n° 016/01 portant code forestier au Gabon. Cet article détaille les différentes parties de la loi relatives à ces dernières et fournit une première interprétation de l’esprit de cette loi et de la volonté du législateur. Les grands thèmes qui y sont défendus tournent autour de la communauté locale, de la décentralisation de la gestion des ressources, de l’aménagement et de la gratuité. La volonté de l’état gabonais d’associer les populations à la gestion de la forêt dans l’optique de contribuer à la réduction de la pauvreté est évidente

Newsletter N° 3 - DACEFI

Développements d'Alternatives à l'Exploitation Forestière Illégal

How host larval age, and nutrition and density of the parasitoid Dinarmus basalis (Hymenoptera: Pteromalidae) influence control of Acanthoscelides obtectus (Coleoptera: Bruchidae)

Choice of the targeted host developmental stage, regulation of parasitoid numbers released and introduction of food supplements are operational factors with a potential to influence the level of biological control. In a closed laboratory storage system maintained over two generations of the host, the impact of these three parameters on the control potential of the parasitoid Dinarmus basalis Rondani was investigated for high populations of larvae of Acanthoscelides obtectus (Say) feeding inside dry common bean seeds Phaseolus vulgaris. The beans were already infested with immature bruchids at the beginning of the storage period to simulate harvest conditions, characterized in a previous study. Treatments resulted in a reduction of 48–75% of the bruchid population within 16 weeks of storage. The best timing of parasitoid release was at the simulated harvest, as later releases reduced the bruchid population only by about half this percentage. Host feeding is postulated to be the key factor involved in the observed difference. The effect of increasing the number of parasitoids strongly depended on host age and food supplement. Addition of vials with honey had no direct effect on the bruchid population or on the parasitoid progeny. The ecological significance of these findings and implications for biological control are discussed.

Circadian Rhythms Differ between Sexes and Closely Related Species of Nasonia Wasps

<p>Activity rhythms in 24 h light-dark cycles, constant darkness, and constant light conditions were analyzed in four different Nasonia species for each sex separately. Besides similarities, clear differences are evident among and within Nasonia species as well as between sexes. In all species, activity in a light-dark cycle is concentrated in the photophase, typical for diurnal organisms. Contrary to most diurnal insect species so far studied, Nasonia follows Aschoff's rule by displaying long (>24 h) internal rhythms in constant darkness but short (</p>

Fulfilling global marine commitments; lessons learned from Gabon

As part of the Post-2020 Biodiversity Framework, nations are assessing progress over the past decade in addressing the underlying drivers that influence direct pressures on biodiversity and formulating new policies and strategies for the decade to come. For marine conservation, global marine protected area (MPA) coverage is still falling short of the 10% target set in 2010. Here we show that while this reflects a lack of progress in many low- and middle-income countries, a few of these nations have met or exceeded international commitments. To provide an in-depth explanation of how this was achieved in Gabon, we summarize the lessons learnt by our consortium of policy makers and practitioners who helped implement a comprehensive and ecologically representative network of 20 MPAs. We show the importance of creating a national framework, building long-term stakeholder support, and focusing on research that guides implementation and policy; and outline a four-step approach that countries and donors could use as an example to help meet international commitments. By responding to calls to share lessons learned to inform future Convention on Biological Diversity targets, we show how Gabon's experiences could inform change elsewhere