Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon

Abstract

Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh <10 cm) comprised 93.7% of the total tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate.

A consensus phylogenomic approach highlights paleopolyploid and rapid radiation in the history of Ericales

“…The flowering plant clade Ericales contains several ecologically important lineages that shape the structure and function of ecosystems including tropical rainforests (e.g., Lecythidaceae, Sapotaceae, Ebenaceae), heathlands (e.g., Ericaceae), and open habitats (e.g., Primulaceae, Polemoniaceae) around the globe (ter Steege et al., ; Hedwall et al., ; He et al., ; Memiaghe et al., ; Moquet et al., ). With 22 families comprising ca.…”

Global importance of large‐diameter trees

“…We further analysed the diameter–abundance relationships of each plot based on six tree diameter classes (1 cm ≤ DBH < 5 cm, 5 cm ≤ DBH < 10 cm, 10 cm ≤ DBH < 30 cm, 30 cm ≤ DBH < 60 cm, 60 cm ≤ DBH < 90 cm and DBH ≥ 90 cm). Diameter classes were selected to include recognized differences in tree life‐history traits (Memiaghe, Lutz, Korte, Alonso, & Kenfack, ). We performed non‐metric multidimensional scaling (NMDS; Kenkel & Orloci, ) analyses on the density of each diameter class of each 100 m × 100 m area.…”

Contenido De Carbono en Un Bosque De Tierra Firme Del Resguardo Nonuya-Villazul, Amazonia Colombiana

“…Este resultado se corresponde con un estudio en Amazonia central donde se reporta hasta de 9.4% para árboles (Nascimento & Laurance, 2002) pero contrasta con otros a nivel mundial que reportan valores promedio de 5.5% (95% IC 4.3-6.9) (Vincent et al, 2015). Este promedio para bosques tropicales proviene de los reportes de 4.8% en Gabón (Memiaghe et al, 2016), entre 2.7-4.2% en Panamá (Chave et al, 2003;Kirby & Potvin, 2007), 7.5-7.8% en la amazonia ecuatoriana (Valencia et al, 2009), 4.58% en Singapur (Ngo et al, 2013) y 7.2% en Papua Nueva Guinea (Vincent et al, 2015).…”