Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 23 Issue 2

The vegetation of the region is the Guineo- Congolese dense forest (White 1983). For Letouzey (1968), FMU 10 025 is in the transition zone between dense, moist evergreen forest and semi-evergreen forest. This FMU was certified by the Forest Stewardship Council (FSC) until 2014, and now it only has a traceability and legality certificate. This study concerned nine legally harvested tree species. In 2013 cutting block of Forest Management Unit 10 025 of SFIL-GDC logging company (SFIL 2009). The selection of these species was based on their commercial potential, the availability of the resource, and the visibility of growth rings among the eighteen species harvested b) Study Species The following species were examined: Afzelia bipendensis Harms, Cylicodiscus gabunensis Harms, Erythrophleum suaveolens A. Chev. and Pterocarpus soyauxii Taub. (Fabaceae); Entandrophragma cylindricum Sprague and Entandrophragma utile (Dawe & Sprague) Sprague (Meliaceae); Milicia exselsa (Welw.) C. C. Berg (Moraceae); Mansonia altissima (A. Chev.) A. Chev. and Triplochiton scleroxylon K.Schum (Malvaceae) (Amougou et al. 2022). The specific wood density was extracted from the Global Wood Density Database (Chave et al. 2009; Zanne et al. 2009). Leaf phenology at the adult stage, regeneration guilds (Hawthrone 1995; Bénédet et al. 2019), and dispersal mode (Hawthrone 1995) at the species level. c) Tree Logging and Sample Collection Tree DBH was measured before trees were felled by a diameter tape. One stem disc was collected at the base of the trunk of each tree (around 0.5 m from the ground or more if buttresses were observed). All stem discs were collected with a chainsaw and immediately they were divided into two halves and each half was divided into three fragments by ensuring that all parts of the stem discs were taken (pith-to-bark). Randomly, a total of 20 fragments of stem discs were collected: 3 fragments of stem discs for M. excelsa , P. soyauxii, and T. scleroxylon ; 2 for A. bipendensis , C. gabunensis , E. cylindricum , E. ivorensis, and 1 for E. utile . The samples were transported by plane to the Royal Museum of Central Africa in Tervuren, Belgium, where they received unique Tervuren wood (Tw) identification numbers and were stored in the Xylarium. (Table 1). a c b 1 Year 2023 67 © 2023 Global Journals Global Journal of Science Frontier Research Volume XXIII Issue ersion I VII ( H ) Wood Density Variations of Tropical Trees Differing in Shade-Tolerance and Leaf Phenology of the Congo Basin Fig. 1: a. Map of Study Site: 2013 cutting block (hatched) of Forest Management Unit 10 025 (wheat), the neighboring Forest Management Unit (pink), and the major village are also shown, b. the climate diagram for the meteorological station in Yokadouma town (1961-2013), c. the inlay shows the location of the study site in Cameroon